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Sequence Stratigraphic Models forExploration and Production:

Evolving Methodology, Emerging Modelsand Application Histories

22nd Annual Gulf Coast Section SEPM FoundationBob F. Perkins Research Conference

2002

Program and Abstracts

Adam’s Mark HotelHouston, Texas

December 8–11, 2002

Edited by

John M. Armentroutand

Norman C. Rosen

ii Program and Abstracts

Copyright © 2002 by theGulf Coast Section SEPM Foundation

www.gcssepm.org

Published December 2002

Publication of the CD ROM Proceedings has been subsidized by generous grants from

Shell Exploration and Production CompanyShell International Exploration and Production

iii22nd Annual Gulf Coast Section SEPM Foundation Bob F. Perkins Research Conference—2002

Dedication

Mention the words “sequencestratigraphy” and the first two wordsthat will occur to you are “Peter Vail.”No matter whether you agree ordisagree with the “Exxon School,” I donot think that anyone could disagreewith the statement that Peter Vail hasbeen not only the most influentialperson in stratigraphy in the past 40years, but he has also greatlyinfluenced the explorationmethodologies in the oil industry.

Upon his retirement from RiceUniversity, a “Vail Fest” conferencewas held to honor him. Weacknowledge that the Foundationhelped support the conference andagreed that we would dedicate theseProceedings to him. This was an easyagreement for us as we had decidedalready that Peter would be elected as aGCSSEPM honorary member. Thenote that follows is from the GCAGS/GCSSEPM Transactions for 2002.

Peter R. Vail: “A Life Dedicated to Stratigraphy”

The spirit of this conference is tohonor Peter R. Vail for his originalconcepts and pioneering work insequence stratigraphy, and tocelebrate his contributions to bothindustry and academia during hiscareer of over 40 years. Thefundamental impact and influence ofhis ideas on industry and academiahave been very significant, and hisearnest desire to teach others both asa professor at Rice University and asa peer is a role that we can all aspire to.

Pete’s ideas on the unifying paradigm ofeustatic cycles are probably as close to anoriginal “breakthrough” concept as most of usare privileged to witness. Pete’s worldwideexperience with Exxon’s research andexploration groups honed the original conceptinto an immensely practical tool forhydrocarbon exploration, and provided a logicalframework in which all geoscientists could builda realistic, predictive stratigraphic frameworkfor their sedimentary rocks, at the seismic oroutcrop scale. His lectures, publications, anduntiring teaching efforts at Rice have made hismethods available to any interpreter or geologistwilling to try them.

Peter Vail graduated from DartmouthCollege in 1952 with an A.B. degree. He

attended Northwestern Universityfrom 1952 to 1956 where he receivedhis M.S. and Ph.D. degrees. AtNorthwestern, he was greatlyinfluenced by Professors Larry Slossand Bill Krumbein, who were at theheight of their work on quantifiedfacies mapping and North Americanunconformity-bounded cratonicsequences. He began his career withExxon in 1956 as a researchgeologist with the Carter Oil

Company, an Exxon affiliate in Tulsa,Oklahoma. He and his wife, Carolyn, reared afamily of three children, who at first grew fasterthan his reputation. He relocated to Houston in1965, at Esso Production Research Company,now ExxonMobil Upstream ResearchCompany, and advanced to a Senior ResearchScientist, the highest technical position.

In 1986, Pete was appointed the W. MauriceEwing Professor of Oceanography at RiceUniversity. Pete continued working toward therefinement and further understanding ofsequence stratigraphic techniques, which arefundamental concepts in common usage by manygeoscientists today. Pete took a sabbatical leavefrom 1992 to 1993 with CNRS in Paris, to lead

Dr. Norman C. Rosen,Executive Director

GCSSEPM Foundation

Peter R. Vail

iv Program and Abstracts

studies of the sequence stratigraphy of Europeanbasins and to revise and document the eustaticcycle chart. He retired from Rice in 2001.

Pete’s ideas evolved naturally from his firstpioneering work on the importance of stratalsurfaces in rocks as geologic time lines. He soonrecognized the cyclic occurrence of bundles ofstrata he called sequences in well logs, seismicreflections, and outcrops. When he began seeingthat sequence boundaries have the same ages inseveral basins worldwide, he postulated thatglobal sea level changes are a major control onthe stratigraphic record, along with basintectonics and sediment supply. This realizationled to the development of eustatic cycle charts.In 1977, these concepts were published in AAPGMemoir 26. His latest SEPM Special Publicationon the sequence stratigraphy of European basinsis a tremendous group effort, which led to amajor revision of the eustatic cycle chart.

In the natural course of his work, Pete has heldmany important roles in a variety of industry,government, and academic-based steeringcommittees, and has received the recognition ofhis peers in the form of many honors both fromacademic institutions and industry-basedsocieties. He served on a number of importantcommittees, including the U.S. Department ofEnergy Committee on Research Drilling (1987-88), the U.S. Geodynamics Committee of theNational Academy of Sciences, and theAmerican Commission on StratigraphicNomenclature. He has been honored byprofessional societies for his outstanding

contributions to geology. A few of his awardsinclude the Virgil Kauffman Gold Medal in 1976for the Advancement of the Science ofGeophysical Exploration by the Society ofExploration Geophysicists, the AmericanAssociation of Petroleum Geologists President’sAward in 1979, and the AAPG’s George C.Matson Memorial Award in 1980. In 1983 he wasthe recipient of the Offshore TechnologyConference Individual DistinguishedAchievement Award. More recently, he wasawarded the Twenhofel Medal by the SEPM(Society for Sedimentary Geology), andHonorary Memberships in the AAPG and SEG.He has been invited by several universities toserve on advisory committees for their GeologyDepartments, including Princeton andNorthwestern. In addition, he was recognized byuniversities and societies in France, Belgium,Scotland, England, and Australia with varioushonorary memberships and awards in recognitionof his leading-edge research work. Lists of hisother honors fill pages!

Pete’s extensive publications list, combinedwith the large number of scientific citations thathis papers receive each year, indicate thesignificance of his work and attest to the fact thathe is one of the most internationally recognizedexperts in the field of sequence stratigraphy.Above all, Pete’s greatest characteristics are hisintegrity, his dedication to his family, and hisfaithfulness to friends, colleagues and students.It is a great honor to have been part of his life.

Robert M. Mitchum and John B. Sangree

v22nd Annual Gulf Coast Section SEPM Foundation Bob F. Perkins Research Conference—2002

Foreword

Sequence stratigraphy as aninterpretation methodology is widelyapplied in petroleum exploration andproduction. This year’s Gulf CoastSection SEPM 22nd Annual Bob F.Perkins Research Conference isentitled “Sequence StratigraphicModels for Exploration andProduction: Evolving Methodology,Emerging Models and ApplicationHistories.” The program committeehas assembled 48 papers on sequencestratigraphy organized into sixcategories: Origin and Evolution of the Model,Variations of Sequence StratigraphicMethodology, Primary Controls on SequenceArchitecture, Primary Controls and CaseHistories, Applications to Exploration, andApplications to Production. Posters includetopics on Case Histories and SequenceCalibration. Depositional environmentsrepresented by case studies include alluvial,fluvial, lacustrine, eolian, coastal plain/deltaic,shelf, slope and basin floor.

In a sense, this year’s conference is an updateof the 1991, 11th Annual Conference titled“Sequence Stratigraphy as an Exploration Tool:Concepts and Practices.” Since that time theconcepts and interpretation methodologies haveevolved through the infusion of well data, cores,high-resolution biostratigraphy, geochemistryand 3D seismic data. Models for interpretationprovide information derived from seismicgeometries and attributes ahead of the drill-bit,and for prediction of reservoir type andperformance in development projects. Thepapers presented in this year’s program representa progress report on the evolution of sequencestratigraphic analysis.

Sequence stratigraphic analysiswas the “brain child” of Peter Vailand his associates at Esso ProductionResearch. It is with great pleasurethat the GCSSEPM dedicates the2002 program in honor of Peter R.Vail. While the development ofseismic sequence stratigraphy, andsubsequently sequence stratigraphy,was a collaborative effort of manygeoscientists, the initial teammembers acknowledge that it wasPeter Vail’s vision of the possible

that lead to the documentation of seismicreflections as time-significant horizons andseismic geometries and attribute facies asproxies for specific depositional environments.

This volume results from the combinedefforts of the program committee and the morethan 100 authors of the papers. All committeemembers and senior authors helped in the reviewprocess. Jory Pacht contributed vision in seekingauthors from a wide spectrum of disciplines.Norm Rosen completed the Herculean effort offinal editing, and Gail Bergan and staff compiledthe CD ROM, overcoming numerous softwarechallenges. Thus, this product reflects the effortsof more than 130 geoscientists. We also want tothank the numerous organizations that employthe contributors and approved publication of thepapers. Preparation of manuscripts forpublication is an arduous process, and themultitude of partners in most exploration andproduction projects requires approval forpublication from many sources. The authors arecommended for their perseverance throughoutthis process. We all benefit from their efforts.

John M. ArmentroutCommittee Co-Chair

vi Program and Abstracts

Gulf Coast Section SEPM Foundation

Trustees and Executive Director

Michael J. Nault, ChairmanApplied Biostratigraphix

Houston, Texas

Rashel N. RosenMicropaleontological Consultant

Houston, Texas

Nancy Engelhardt-MooreGeoFix-It Consulting

Houston, Texas

Michael J. Styzen

Shell International E&P Deepwater Services

New Orleans, Louisiana

Norman C. Rosen, Executive Director

NCR & Associates

Houston, Texas

Executive Council

President

Tony D’AgostinoPGS Reservoir Consultants

Houston, Texas

Vice President

Jory A. PachtSeis-Strat Services

Houston, Texas

Treasurer

Terri M. DunnNannofossil ConsultantNew Orleans, Louisiana

President Elect

Richard FillonEarth Studies AssociatesNew Orleans, Louisiana

Secretary

Lana CzerniakowskiConocoPhillipsHouston, Texas

Past-President

Ron F. WaszczakConocoPhillipsHouston, Texas

Audio-Visual and Poster Committee

Michael J. Nault (Co-Chairman)

Applied Biostratigraphix

Houston, Texas

Nancy Engelhardt-Moore (Co-Chairman)

GeoFix-It Consulting

Houston, Texas

Jerri Fillon

Earth Studies Associates

New Orleans, Louisiana

Arden Callender

Applied Biostratigraphix

Houston, Texas

vii22nd Annual Gulf Coast Section SEPM Foundation Bob F. Perkins Research Conference—2002

22nd Annual Bob F. Perkins Research Conference Program Advisory Committee Co-Chairmen

John M. ArmentroutCascade StratigraphicClackamas, Oregon

Jory A. PachtSeis-Strat Services

Houston, Texas

Marty A. PerlmutterChevronTexaco, Inc.

Houston, Texas

Grant D. WachDalhousie UniversityHalifax, Nova Scotia

Program Advisory Committee

Robert MitchumConsultant

Peter VailRice University

Nancy Engelhardt-MooreGeoFix-it Consulting

Barbara RadovichIntegrated Geophysics

Mary CarrColorado School of Mines

Michael GardnerColorado School of Mines

Gregg BlakeUnocal

David DockeryMississippi Department of Natural Resources

viii Program and Abstracts

Contributors to the Gulf Coast Section SEPM Foundation

Sponsorship Categories

Please accept an invitation from the GCSSEPM Section and Foundation for your support ofGeological and Geophysical Staff and Graduate Student Education in Advanced Applications ofGeological Research to Practical Problems of Exploration, Production, and Development Geology.

The GCSSEPM Foundation is NOT part of the SEPM Foundation. In order to keep ourconferences priced at a low level and to provide funding for university staff projects and graduatescholarships, we must have industrial support. The GCSSEPM Foundation provides severalcategories of sponsorship. In addition, you may specify, if you wish, that your donation be appliedto Staff support, Graduate support, or support of our Conferences. Please take a moment and reviewour new sponsor categories for 2002, as well as our current and past sponsors. In addition, we askthat you visit our sponsor's web site by clicking on their logo or name. Thank you for your support.

Corporate SponsorshipsDiamond

($15,000 or more)Platinum

($10,000 to $14,999)Gold

($6,000 to $9,999)Silver

($4,000 to $5,999)Bronze

($2,000 to $3,999)Patron

($1000 to $1,999)

Individuals & Sole ProprietorshipsDiamond

($3,000 or more)Platinum

($2,000 to $2,999)Gold

($1,000 to $1,999)Silver

($500 to $999)Bronze

($300 to $499)Patron

($100 to $299)

Sponsor Acknowledgment

For 2002, all sponsors will be prominently acknowledged on a special page inserted in the 2002and 2003 conference abstracts volume and CDs and with large placards strategically placedthroughout the meeting areas during these conferences.

Corporate level Diamond sponsors will be acknowledged by having their logo displayed on theback jewel box cover of the Conference CD. Corporate level Platinum sponsors will beacknowledged by having their logo placed on the first page of the CD. All contributions used forscholarships and/or grants will be given with acknowledgment of source.

In addition to the recognition provided to our sponsors in GCSSEPM publications, we proudlyprovide a link to our sponsors’ home Web site. Just click on their logo or name to visit respectiveGCSSEPM sponsors.

The GCSSEPM Foundation is a 501(c)(3) exempt organization. Contributions to it are taxdeductible as charitable gifts and contributions.

For additional information about making a donation as a sponsor or patron, please contact Dr.Norman C. Rosen, Executive Director, GCSSEPM Foundation, 2719 S. Southern Oaks Drive,Houston, TX 77068-2610. Telephone (voice or fax) 281-586-0833 or e-mail [email protected].

ix22nd Annual Gulf Coast Section SEPM Foundation Bob F. Perkins Research Conference—2002

2002 Sponsors

Corporate Sponsorships

Platinum

Shell E&P CompanyShell International E&P

Silver

Bronze

Patron

Individuals & Sole Proprietorships

Gold

SilverMichael J. Nault

Edward B. Picou, Jr.

PatronNancy Engelhardt-Moore

Paul J. PostWalter Pusey

2001 Sponsors

Platinum SponsorsUNOCAL Deepwater USA

Gold SponsorsBHPbilliton

bp ExplorationShell Exploration and Production

Silver SponsorsExxonMobil

Ocean Energy

Bronze SponsorsAgip Petroleum Company

Amerada HessConoco GOM Deep Water Business Unit

Conoco Exploration Production TechnologyDominion Exploration and Production

Kerr-McGee CorporationMariner Energy

Phillips PetroleumNorman C. and Rashel N. Rosen

Roxar, Inc.

http://www.bp.com

http://www.bp.com

http://www.shell.com

http://www.shell.com

http://www.unocal.com/

http://www.unocal.com/

http://www.conocophillips.com/

http://www.conocophillips.com/

http://www.hess.com/




http://www.oceanenergy.com/

http://www.kerr-mcgee.com/

http://www.kerr-mcgee.com/

http://www.paleodata.com/

http://www.paleodata.com/

x Program and Abstracts

Credits

Graphics Design and CD ROM Publishing

Houston, Texas

www.bergan.com

Cover Images

The three images used on the cover of this Program appear in papers in the conferenceproceedings:

Anderson, Keeping Pace: Continental (Nonmarine) Sequence Stratigraphy in a HighAccommodation-Sediment Supply Regime, Hornelen Basin (Devonian), Norway, Figure 4: faciesarchitecture map;

Dean et al., Multiple Fields within the Sequence Stratigraphic Framework of the Greater AugerBasin, Gulf of Mexico, Figure 7: three-dimensional perspective of three reservoirs;

and

Steel and Olsen, Clinoforms, Clinoform Trajectories and Deepwater Sands, Figure 3B: outcropphotograph of clinoforms.

xi22nd Annual Gulf Coast Section SEPM Foundation Bob F. Perkins Research Conference—2002

Sequence Stratigraphic Models for Exploration and Production: Evolving Methodology, Emerging Models and Application Histories

22nd Annual Gulf Coast Section SEPM Foundation Bob F. Perkins Research Conference

Adam’s Mark HotelHouston, Texas

December 8–11, 2002

Program and Abstracts

Sunday, December 8

4:00–6:00 p.m. Registration (Grand Foyer) and Poster Setup (Grand Pavilion)

6:00–8:00 p.m. Welcoming Reception and Poster Preview (Grand Pavilion)

Monday, December 9

7:00 a.m. Continuous Registration (Grand Foyer)

7:45 a.m. Welcome: Michael Nault, Chairman of the Board of Trustees, GCSSEPM Foundation(Grand Pavilion)

7:50 a.m. Introduction and Welcome: John Armentrout, Program Chair (Grand Pavilion)

Session I—Origin and Evolution of the Model

Presiding: Jory Pacht and Trey Meckel

8:00 a.m. Mitchum, Robert M., Peter R. Vail and John B. Sangree ...................................................1Sequence Stratigraphy: Evolution and Effects

8:30 a.m. Vail, Peter R., Robert M. Mitchum and John B. Sangree ....................................................2Concepts of Depositional Sequences

9:00 a.m. Brown, L. Frank, Jr., Robert G. Loucks and Ramón H. Treviño .......................................3Sequences, Depositional Systems, and Synsedimentary Tectonics, Oligocene Rocks, Corpus Christi Region, South Texas: Revisiting Mature Fields with New Prospecting Tactics

9:30 a.m. Refreshment Break and Poster Viewing

xii Program and Abstracts

10:00 a.m. Posamentier, Henry W. .......................................................................................................4Sequence Stratigraphy Past, Present and Future, and the Role of 3D Seismic Data

10:30 a.m. Zeng, Hongliu and Tucker R. Hentz ....................................................................................5High-Frequency Sequence Stratigraphy from Seismic Sedimentology: A Miocene Gulf Coast Example

11:00 a.m. Apps, Gillian M., Michael G. Moore, Mark A. Woodall and Bryan C. Delph ....................6Using Sequence Hierarchy to Subdivide Miocene Reservoir Systems of the Western Atwater Foldbelt, Ultra Deep Water, Gulf of Mexico

11:30 a.m. Snedden, John W., J.F. (Rick) Sarg and Yudong (Don) Ying .............................................7Exploration Play Analysis from a Sequence Stratigraphic Perspective

12:00–1:30 p.m. Lunch and Open Poster Booths

Session II—Variations of Sequence Stratigraphic Methodology

Presiding: Marty A. Perlmutter and Michelle Kominz

1:30 p.m. Galloway, William E. and Dennis A. Sylvia .......................................................................8The Many Faces of Erosion: Theory Meets Data in Sequence Stratigraphic Analysis

2:00 p.m. Meckel, Lawrence D., Gustavo A. Ugueto, H. David Lynch, Earl W. Cumming,Ben M. Hewett, Eric J. Bocage, Charlie D. Winker and Brian J. O’Neill ............................9

Genetic Stratigraphy, Stratigraphic Architecture, and Reservoir Stacking Patterns of the Upper Miocene—Lower Pliocene Greater Mars-Ursa Intraslope Basin, Mississippi Canyon, Gulf of Mexico

2:30 p.m. Bhattacharya, Janok, P. ....................................................................................................11Allostratigraphy versus Sequence Stratigraphy

3:00 p.m. Refreshment Break and Poster Viewing

3:30 p.m. Embry, Ashton F. ...............................................................................................................12Transgressive-Regressive (T-R) Sequence Stratigraphy

4:00 p.m. Mancini, Ernest A. and T. Markham Puckett ....................................................................13Transgressive-Regressive Cycles: Application to Petroleum Exploration for Hydrocarbons Associated with Cretaceous Shelf Carbonates and Coastal and Fluvial-Deltaic Siliciclastics, Northeastern Gulf of Mexico

4:30 p.m. Anderson, Donna S. ..........................................................................................................14Keeping Pace: Continental (Nonmarine) Sequence Stratigraphy in a High Accommodation-Sediment Supply Regime, Hornelen Basin (Devonian), Norway

5:00 p.m. Holbrook, John and Francisca E. Oboh-Ikuenobe ............................................................15Bounding-Surface Hierarchies and Related Sources of Heterogeneity in Seemingly Uniform Fluvial Sandstone Sheets

5:30–8:00 p.m. Hot Buffet and Poster Session

xiii22nd Annual Gulf Coast Section SEPM Foundation Bob F. Perkins Research Conference—2002

Tuesday, December 10

Session III—Primary Controls on Sequence Architecture

Presiding: Grant D. Wach and John Holbrook

8:00 a.m. Perlmutter, Martin A. and Roy E. Plotnick ......................................................................16Predictable Variations in the Marine Stratigraphic Record of the Northern and Southern Hemispheres and Reservoir Potential

8:30 a.m. Tinker, Scott W. and Charles Kerans .................................................................................17Depositional Topography: Key Element of Stratigraphic Interpretation and Panacea for Log Correlation: Part 1: Concepts and Transitional Icehouse-Greenhouse Systems

9:00 a.m. Kerans, Charles and Scott W. Tinker ................................................................................18Depositional Topography: Key Element of Stratigraphic Interpretation and Panacea for Log Correlation: Part 2: Concepts and Transitional Icehouse-Greenhouse Systems

9:30 a.m. Refreshment Break and Poster Viewing

10:00 a.m. Cecil, C. Blaine, Frank T. Dulong, Ronald R. West and N. Terence Edgar .......................19Paleoclimate and the Origin of Middle Pennsylvanian Cyclothems (Fourth-Order Sequences) of North America

10:30 a.m. Roberts, Harry H., John Sydow, Richard Fillon and Barry Kohl .....................................20Stratigraphic Architecture and Fundamental Sedimentology of Two Late Pleistocene Deltas: Gulf of Mexico and Indonesia

11:00 a.m. Kominz, Michelle A., William A. Van Sickel, Kenneth G. Miller and James V. Browning 21Sea-Level Estimates for the latest 100 Million Years: One-Dimensional Backstripping of Onshore New Jersey Boreholes

11:30 a.m. Miller, Kenneth G., James V. Browning, James D. Wright, Gregory S. Mountain,John C. Hernandez, Richard K. Olsson, Mark D. Feigenson, Michelle A. Kominz,William A. Van Sickel and Peter J. Sugarman .....................................................................22

ODP, Sequences, and Global Sea-Level Change: Comparison of Icehouse vs. Greenhouse Eustatic Changes

12:00–1:30 p.m. Lunch and Open Poster Booths

Session IV—Primary Controls and Case Histories

Presiding: Tony D’Agostino and Ken Nibbelink

1:30 p.m. Bohacs, Kevin M., Jack E. Neal and George J. Grabowski, Jr. .........................................23Sequence Stratigraphy in Fine-Grained Rocks: Beyond the Correlative Conformity

2:00 p.m. Kominz, Michelle A. and Stephen F. Pekar .......................................................................24Sequence Stratigraphy and Eustatic Sea Level

xiv Program and Abstracts

2:30 p.m. Steel, Ron and Torben Olsen ..............................................................................................25Clinoforms, Clinoform Trajectories and Deepwater Sands

3:00 p.m. Refreshment Break and Poster Viewing

3:30 p.m. Wagner, John B., Janok Bhattacharya, Kristian Soegaard, Richard J. Moiola andJames M. Coleman...............................................................................................................26

Allocyclic and Autocyclic Processes as Primary Controls on the Stratal Architecture and Sedimentological Expression of Depositional Systems from the Bolivian Sub-Andean Foreland Basin

4:00 p.m. Llinas, Juan Carlos ...........................................................................................................27Influence of Paleotopography, Eustasy and Tectonic Subsidence: Upper Jurassic Smackover Formation, Vocation Field, Manila Subbasin (Eastern Coastal Plain)

4:30 p.m. Bohacs, Kevin M., Jack E. Neal, George J. Grabowski, Jr., David J. Reynolds andAlan R. Carroll 28

Controls on Sequence Architecture in Lacustrine Basins—Insights for Sequence Stratigraphy in General

5:00 p.m. Sweet, Michael L. ..............................................................................................................29Contrasting Styles of Eolian, Fluvial and Lacustrine Sequence Development:UK Southern North Sea

5:30–8:00 p.m. Beer, Wine and Snacks, Poster Session

8:00 p.m. Authors remove posters (display boards removed at 8:15 p.m.)

Wednesday, December 11

Session V—Applications to Exploration

Presiding: Donna Anderson and John Wagner

8:00 a.m. Liro, Louis M. and Kimberly Cline ...................................................................................30Extracting Stratigraphic Information from 3D: Exploiting the Seismic Data

8:30 a.m. Radovich, Barbara J. ........................................................................................................31Cyclic Attributes on Seismic Data and Sequence Stratigraphy—New Criteria for Exploration, New Interpretation Styles

9:00 a.m. Nibbelink, Ken A. and J. D. Huggard ................................................................................32Oligocene/Miocene Depositional System, Volta Fan Fold Belt, Ghana

9:30 a.m. Refreshment Break

10:00 a.m. Houseknecht, David W. and Christopher J. Schenk ..........................................................33Sequence Stratigraphic Framework for Oil- and Gas-Prospective Brookian Turbidites, National Petroleum Reserve in Alaska (NPRA)

xv22nd Annual Gulf Coast Section SEPM Foundation Bob F. Perkins Research Conference—2002

10:30 a.m. Klein, George D. and Kenneth R. Chaivre .........................................................................34

Sequence and Seismic Stratigraphy of the Bossier Formation (Tithonian; Uppermost Jurassic), Western East Texas Basin

11:00 a.m. Nummedal, Dag and John R. Suter ....................................................................................35

Continental Shelf Sand Ridges: Genesis, Stratigraphy and Petroleum Significance

11:30 p.m. May, Jeffrey A., Mark S. Przywara, Thomas A. Mazza, Ruble Clark, John Dlouhy andRoger Hettenhausen ............................................................................................................36

Amplitude Anomalies in a Sequence Stratigraphic Framework: ExplorationSuccesses and Pitfalls in a Subgorge Play, Sacramento Basin, California

12:00–1:30 p.m. Lunch Break

Session VI—Applications to Production

Presiding: Marcello Badali` and Gillian Apps

1:30 p.m. Handford, C. Robertson, Dave L. Cantrell and Thomas H. Keith ...................................37

Regional Facies Relationships and Sequence Stratigraphy of a Super-Giant Reservoir (Arab-D Member), Saudi Arabia

2:00 p.m. D’Agostino, Anthony E. and J. Michael Party ..................................................................38

Facies and Sequence Stratigraphy of the Abo Formation in the Kingdom Field Area,Terry and Hockley Counties, West Texas

2:30 p.m. Kong, Fanchen, Guillermo Jalfin, Pujianto Lutkito and Ichsan Sarkawi ..........................39

Sequence Stratigraphic Framework in a Humid Alluvial Fan Complex,Quiriquire Oil Field, Venezuela

3:00 p.m. Refreshment Break

3:30 p.m. Howell, John and Stephen Flint ..........................................................................................40

Application of Sequence Stratigraphy in Production Geology and 3-D Reservoir Modeling

4:00 p.m. Phelps, Jeanne S.F., Jonathan L. Jee, Michael A. Fogarty and R. David Phelps ..............41

Examples of Fluvial Stratigraphy in the Wilcox Group, Louisiana as Revealed byHigh-Resolution 3D Seismic Data

4:30 p.m. Winker, Charles D. and R. Craig Shipp ............................................................................42

Sequence Stratigraphic Framework for Prediction of Shallow Water Flow in theGreater Mars-Ursa Area, Mississippi Canyon Area, Gulf of Mexico Continental Slope

5:00 p.m. Dean, Michael C., James R. Booth and Bruce T. Mitchell ................................................43

Multiple Fields within the Sequence Stratigraphic Framework of the Greater Auger Basin,Gulf of Mexico

xvi Program and Abstracts

Poster Only: Case Histories and Sequence Calibration

Badali`, Marcello .........................................................................................................................................44A Simple Methodology for Carbonate Sequence Stratigraphic and Seismic Stratigraphic Interpretation:Examples from the Lower Cretaceous Section in Offshore Alabama and Mississippi

Houseknecht, David W. ...............................................................................................................................45Squinting Through Leaded Glass: A Public Domain View of the Alpine Play in the National PetroleumReserve in Alaska (NPRA)

Mitchum, Robert M. and Grant D. Wach ....................................................................................................46Niger Delta Pleistocene Leveed-Channel Fans: Models for Offshore Reservoirs

Warren, Jeffrey D. and Louis R. Bartek, III.................................................................................................47The Sequence Stratigraphy of the East China Sea: Where are the Incised Valleys?

Wilson, James, Mark Holbrook and Jim Jones ............................................................................................48Oil Exploration Under the Catastrophic Paradigm

Wornardt, Walter W., Jr. ............................................................................................................................49Ages of Maximum Flooding Surfaces and Revisions of Sequence Boundaries and Their Ages, Cenozoic to Triassic

Author Index.............................................................................................. A-1

122nd Annual Gulf Coast Section SEPM Foundation Bob F. Perkins Research Conference—2002

Sequence Stratigraphy: Evolution and Effects

Mitchum, R. M.Consultant13039 PebblebrookHouston, Texas 77079e-mail: [email protected]

Vail, P. R.Professor EmeritusRice UniversityHouston, Texas

Sangree, J. B.Consultant13724 A La Entrada CalleCorpus Christi, Texas 78418

AbstractIn many ways, sequence stratigraphy’s effect on

stratigraphic interpretation is comparable to that of plate tec-tonics on structural geology. These are markers in the historyof geology upon which talented minds can build the nextadvances. However, concepts that seem self-evident totoday’s students faced painful periods of ridicule and resis-tance when first systematized by Peter Vail in the 1960s. Thehistory of this slow acceptance is marked by a gradual evolu-tion of concepts that bring basin tectonics, sea-levelfluctuations, and sediment supply into an integrated strati-graphic solution.

One basic idea is the time-significance of stratal sur-faces and surfaces of discontinuity, and of the seismicreflections generated by them. Another concept is that cyclicsedimentary sequences form in response to varying rates ofeustatic changes, tectonic subsidence, and sedimentary sup-

ply. The sequence model is highly variable but astonishinglyrobust in predicting facies and environments in a wide vari-ety of basin and tectonic settings.

Applications in industry and academia are wide-spread, especially in predicting deep-marine sands, seals,and source rocks in offshore settings. Other specific applica-tions include sequence stratigraphy of carbonates, estuarinesands, incised valleys, forced regressions, and well-log andoutcrop analysis. Development of eustatic cycle charts needshigh-quality biostratigraphy for dating and environmentalanalysis. Advent of 3-D seismic data opens a myriad of usesinvolving attributes of the seismic signal. No matter howspecialized, however, the good interpreter always starts witha rigorously defined chronostratigraphic framework ofsequences and systems tracts for proper interpretation.

mailto:[email protected]

2 Program and Abstracts

Concepts of Depositional Sequences

Vail, Peter R.Professor EmeritusRice UniversityHouston, Texas

Mitchum, Robert M.Consultant13039 PebblebrookHouston, Texas 77078

Sangree, John B.Consultant13729 A La Entrada CalleCorpus Christi, Texas 78418

AbstractThe depositional sequence was defined in 1977 as “a

stratigraphic unit composed of a relatively conformable suc-cession of genetically related strata and bounded at its topand base by unconformities or their correlative conformi-ties.” This definition has proven singularly robust in anynumber of sedimentary and tectonic settings.

The depositional sequence model evolves naturallyfrom recognition of stratal surfaces in rocks as geologicaltime lines and from the time-significance of unconformitiesand their correlative conformities as sequence boundaries.Seismic reflections follow stratal boundaries, and withinlimits of seismic resolution, represent time lines.

Sequence boundaries have been found to be of thesame age in basins worldwide, and it has been postulatedthat global sea level changes are a major control on thestratigraphic record, along with local basin tectonics andrates of sediment supply. Eustatic cycle charts plot the agesand magnitudes of global eustatic cycles. High-resolutionbiostratigraphy is essential to dating sequences and deter-mining paleo-environments.

The cyclic sequences bounded by these unconformi-ties have a basic pattern of deposition which results from arelative fall and rise of sea level. This pattern can vary

widely from basin to basin, depending on variations in basintectonics and sediment supply. The accommodation modelconsists of lowstand, transgressive, and highstand systemstracts formed in response to various stages of the sea-levelcycle.

The maximum flooding surface marks the maximumtransgression of marine facies on the shelf, and is an impor-tant correlation point. It is not a sequence boundary in ourmodel because strata bounded by maximum flooding sur-faces would include two disparate units separated by asignificant unconformity, which is our sequence boundary.

Several levels of sea level cyclicity may occur in ahierarchy that allows higher frequency cycles to be super-posed or stacked into lower frequency cycles. The stackingof parasequences (fourth- or fifth-order cycles) into third-order (sequence) cycles is an example.

Examples of stratigraphic sections from the Paleozoicof the Arabian plate and the northern Gulf of Mexico showapplications of sequence stratigraphy to both extremes of thePhanerozoic spectrum. They also contrast characteristics ofthe best-known models of sedimentary response to cyclicdepositional control.


Sequences, Depositional Systems, and Synsedimentary Tectonics, Oligocene Rocks, Corpus Christi Region, South

Texas: Revisiting Mature Fields with New Prospecting Tactics

Brown, L. Frank, Jr.Bureau of Economic GeologyJohn A. and Katherine G. Jackson School of GeosciencesThe University of Texas at AustinUniversity Station Box XAustin, Texas 78713 e-mail: [email protected]

Loucks, Robert G. Bureau of Economic GeologyJohn A. and Katherine G. Jackson School of GeosciencesThe University of Texas at AustinUniversity Station Box XAustin, Texas 78713e-mail: [email protected]

Treviño, Ramón H. Bureau of Economic GeologyJohn A. and Katherine G. Jackson School of GeosciencesThe University of Texas at AustinUniversity Station Box XAustin, Texas 78713e-mail: [email protected]

Abstract

Subregional 3-D seismic volumes and wireline logspermitted definition of second- to fifth-order (~10 my–10ky) Frio and Anahuac (Oligocene) sequences, systems tracts,and associated syntectonics. Third- and most fourth-ordersequences were correlated within several subregional wire-line-log and seismic networks. Vicksburg and Miocenesequences were of secondary interest. Composite sequencelogs characterized principal fields. Sequence analysis identi-fied and correlated all key surfaces: type 1 unconformities,maximum-flooding surfaces, and transgressive surfacesbounding systems tracts. Although microfossil occurrencesare not necessarily required for sequence analysis, limiteddata were integrated with the final sequence frameworks,providing secondary verification of assigned ages.

Lithostratigraphic Frio and Anahuac strata comprise sixchronostratigraphic, third-order depositional sequences(~32.0–23.6 Ma) and myriad fourth- and fifth-order sequencesor parasequence sets. Except for incised valley fills, lowstandtracts comprise off-shelf systems deposited within active,growth-faulted, intraslope subbasins. Maximum Anahuacflooding (~24.57 Ma) provides a regional, dated marker towhich latest published ages of sequence surfaces have beencalibrated. Maximum flooding surfaces and type 1 unconfor-mities are essentially isochronous, but sand-rich lithofacies are

mostly diachronous. Off-shelf and on-shelf deposition aretemporally unique. Many previously inferred Frio “stackedbarriers” are dip-oriented incised valley-fill facies.

Seaward, lowstand sedimentary wedges and super-posed shelves become younger. Entrenched rivers supplysediments via ephemeral deltas for gravity transport to basinfloor and slope fans. Eventually, overloaded lowstand depo-centers initiate gravity faulting, mobilized mud, and, hence,produce younger faulted, shale-withdrawal subbasins.Diminished faulting permits lowstand deltas to extend shelfedges basinward until the deltaic ramps are anchored at thebasinward margin of buried subjacent shale-ridges. Theseshale buttresses stabilize the upper continental slope andshelf edge. During a later cycle, highstand shorelines pro-grade basinward over the shallow, lowstand ramps. On-shelfregression eventually stalls by increasing accommodationspace near the continental shelf edge, establishing anotherdepocenter and intraslope subbasin.

Gas in lowstand deltaic and distal valley-fill reservoirsis trapped updip against hanging walls of extensional faultsoverlying shale-cored anticlines. Combination trapping andbasin-floor and slope-fan reservoirs are viable targets.Sequence ideas offer new, but deeper prospecting targets.





Sequence Stratigraphy Past, Present and Future,and the Role of 3-D Seismic Data

Posamentier, Henry W. Anadarko Canada Corporation

425 1st Street SWCalgary, Alberta T2P 4V4Canadae-mail: [email protected]

AbstractIn the twenty-five years since the landmark publica-

tion of AAPG Memoir 26 and later, SEPM SpecialPublication 42, the concepts of sequence stratigraphy haveevolved rapidly. This discipline, an outgrowth of seismicstratigraphy, has spread far beyond applications to 2-D seis-mic data alone. Sequence stratigraphy has seen applicationsembracing data sets ranging from biostratigraphic togeochemical to physical oceanographic, and from boreholeto outcrop, and finally, coming full cycle, to 3-D seismicdata. Initially the domain of industry geoscientists, sequencestratigraphy has gained widespread acceptance among geo-scientists in all professions, having been recognized as anapproach that facilitates integration of a broad range ofdisciplines.

The evolution of sequence stratigraphic concepts isfar from complete. In particular, recent increased availabilityof high-quality 3-D seismic coverage promises to provideinsights that will lead to further fine tuning of sequence con-cepts. In addition to enhanced 2-D profiles, 3-D seismic dataafford exceptional plan views of the subsurface that in thepast could only be inferred. These plan view images now

comprise a fundamental starting point from which geologicanalyses and interpretation can begin. Such images depictpaleo-landscapes, which can be analyzed using time-hon-ored principles of geomorphology, leading to thedevelopment of the discipline of seismic geomorphology.When used in conjunction with seismic stratigraphy, seismicgeomorphology can significantly enhance sequence strati-graphic interpretations.

The identification of depositional elements such aschannels, valleys, shore faces, shelf ridges, etc., in plan view,can be integrated with seismic stratigraphic analyses of asso-ciated seismic profiles to calibrate profile reflection patternsand refine analyses of basin fill histories. Systematic seismicgeomorphologic analysis of 3-D seismic volumes can bringto light spatial and temporal relationships of successive dep-ositional systems. Moreover, recognition of these systemsand analyses of their succession can help in the identificationof possible missing facies tracts. This approach, coupledwith direct and indirect recognition of unconformities, com-prises an integral aspect of sequence stratigraphicinterpretation.



High-Frequency Sequence Stratigraphy from Seismic Sedimentology: A Miocene Gulf Coast Example

Zeng, HongliuBureau of Economic GeologyJohn A. and Katherine G. Jackson School of GeosciencesThe University of Texas at AustinUniversity Station, Box XAustin, Texas 78713e-mail: [email protected]

Hentz, Tucker F.Bureau of Economic GeologyJohn A. and Katherine G. Jackson School of GeosciencesThe University of Texas at AustinUniversity Station, Box XAustin, Texas 78713e-mail: [email protected]

AbstractFor high-frequency (fourth-order) depositional

sequences, seismic-stratigraphic interpretation of verticalseismic sections commonly generates equivocal sequenceboundaries and systems tracts because of limited verticalseismic resolution. Extending well-based, high-frequencysequence stratigraphy into a 3-D seismic survey area conse-quently proves to be a major challenge. We show that criticalto such extension is recognition and interpretation of plano-form geomorphology of depositional systems. Emphasisshould be shifted from interpreting vertical seismic data todeveloping new tools capable of extracting more horizontal,seismic-sedimentologic information. This case study of the

Vermilion Block 50-Tiger Shoal field area, offshore Louisi-ana, shows that proportional, stratal slicing betweenMiocene flooding surfaces provides sequential and accurateseismic imagery of depositional systems. This imagery inturn serves as a basis for recognizing and mapping high-fre-quency systems tracts, sequence boundaries, and sequencesin a geologic-time domain. In the Miocene interval, all of thefourth-order sequences or sequence sets from study wellscan be seismically mapped at a resolution equivalent to 10 min thickness, which is necessary for accurate reconstructionof the high-frequency sequence-stratigraphic framework inthe region of seismic coverage outside well control.




Using Sequence Hierarchy to Subdivide Miocene Reservoir Systems of the Western Atwater Foldbelt,

Ultra Deep Water Gulf of Mexico

Apps, Gillian M.Moore, Michael G.Woodall, Mark A.Delph, Bryan C.BHPBilliton Petroleum, Americas Inc.Houston, Texas

Abstract

Recent major discoveries at Mad Dog, Atlantis, andNeptune have opened a major new hydrocarbon province inthe Western Atwater Foldbelt of the ultra-deepwater Gulf ofMexico. The hydrocarbons are reservoired in good qualityLower and Middle Miocene turbidite sandstones. There is aclear stratigraphic signature expressed in the ultra-deepwater, with the principal reservoir sands strongly partitionedinto discrete, high net/gross, laterally extensive bodies, at orclose to interpreted sequence boundaries. The upper part ofthe sequence is dominated by thin-bedded turbidites andmudstones.

Good quality biostratigraphic data allow us to corre-late third and fourth order stratigraphic boundaries throughall the wells across the region. Seismic data, south of theSigsbee salt, for these deeper, older reservoirs provides reso-lution of the third order sequence boundaries. Compensationcycles have been mapped between the third order sequenceboundaries, but it is not certain that these directly correspondto the fourth order sequences.

The observed stratigraphic hierarchy starts at secondorder cyclicity, demonstrated by a systematic change in thedistribution of net sand from one third order sequence to thenext. The highest resolution sequences that we have beenable to map are fifth order. As expected, there is a systematicrelationship between the stratigraphic hierarchy and the lat-eral correlation length of stratigraphic surfaces; ie.condensed sections associated with third order sequencescan be correlated over greater lengths than the flood surfacesassociated with higher order sequences. Third ordersequence boundaries are mapped over a distance of in excessof a hundred miles. Fourth order boundaries have been cor-related with confidence over a distance of at least 30 miles,

and the fifth order correlation surfaces can only be mappedconfidently within a single field, a distance of a few miles.

The nature of the flood surfaces changes with theposition in the stratigraphic hierarchy and with the locationrelative to the sand feeder systems. In the core of the deposi-tional system, we do not observe the foraminiferal marls thatare characteristic of significant condensed sections else-where in the Gulf of Mexico. Our interpretation is thatsediment is being supplied continuously to the basin floor inthe form of sediment gravity flows and suspended sedimentfall out from turbidity currents. As a result, third order flood-ing surfaces are characterized by high gamma shales, fourthorder flooding surfaces are commonly associated with inter-vals of thin bedded turbidites; and fifth order flood surfaceshave a variety of log signatures, and a ranges of facies asso-ciation. Away from the focus of sediment input,foraminiferal marls are observed and some are interpreted torepresent condensed sections.

The detailed high frequency sequence stratigraphythat has been carried through the three principal discoveriesin the Western Atwater Foldbelt has impacted the explora-tion and development strategy for the area. For example, wehave been able to demonstrate the presence of significantpaleotopography that affected the lowermost Miocene reser-voir distribution. We have proven that the thick sand bodiesassociated with the third order sequence boundaries are lat-erally extensive and so have reduced the risk of finding goodquality reservoir sands in appraisal wells and nearby explo-ration wells. We have also demonstrated that not all floodsurfaces are created equal and are therefore likely to havedifferent transmissibility properties. This could have a sig-nificant impact on fluid flow within the reservoir andtherefore medium and long-term field development.


Exploration Play Analysis from aSequence Stratigraphic Perspective

Snedden, John W.Sarg, J. F. (Rick)ExxonMobil Exploration CompanyPO Box 4778Houston, Texas 77210-4778e-mail: [email protected]: [email protected]

Ying, Yudong (Don)ExxonMobil Upstream Research CompanyP.O. Box 2189Houston, Texas 77252-2189e-mail: [email protected]

Abstract

Examination of exploration drilling histories formany different global basins indicates a counter-intuitivetemporal and spatial pattern in the way hydrocarbons aresometimes discovered. Conventional wisdom holds that forany given basin or play, a plot of cumulative discoveredhydrocarbon volumes versus time or number of wells drilledgenerally show a steep curve (rapidly increasing volumes)early in the play history and a later plateau or terrace (slowlyincreasing volumes). Such a plot is called a creaming curve,as early success in a play is thought to inevitably give way tolater failure as the play or basin is drilled-up. It is commonlythought that the “cream of the crop” of any play or basin isfound early in the drilling history.

By examining plays or basins with sufficiently longdrilling histories and range of reservoir paleoenvironmentand trap types, one actually finds two or three “terraces” tothe creaming curve. The first string of successes in a givenbasin generally corresponds to exploitation of the highstandsystems tract or sequence set reservoirs developed in updipstructural traps. These reservoirs are typically marginal toshallow marine “shelfal” deposits, laterally continuous butlacking internal sealing facies and are seldom self-sourcing.The second or third terrace in the creaming curve usuallyinvolves the lowstand reservoir component (systems tract or

sequence set), which is often developed in downdip deepwa-ter or slope paleoenvironments. Transgressive (systems tractor sequence set) reservoirs, typically shallow marine shelfalsandstones that are sometimes self-sourced, are variablydeveloped and may or may not occupy the second terrace ofthe creaming curve. These trends hold true for both second-order (3–10 my) and/or third-order (1–3 my) stratigraphiccycles, depending upon the scale of the basin or play.

This analysis fits well with the definition of an explo-ration play provided by Magoon and Sanchez (1995): a fullydeveloped play is the simple volume difference between thepetroleum system capability and the current discoveredhydrocarbon volumes (commercial or not). Where the differ-ence is large, either the petroleum system has significantleakage problems (e.g., Barents Sea Mesozoic play) or thelowstand systems tract or sequence set has not been fullyexploited.

Examples supporting these ideas are drawn from sev-eral global basins (Gulf of Mexico Miocene, Norway UpperJurassic, Mahakam Delta, and Texas Wilcox). Case studiesdemonstrate how critical elements of exploration risk shiftfrom trap and seal in highstand plays to reservoir and sourcein lowstand components of these plays.





The Many Faces of Erosion: Theory Meets Data inSequence Stratigraphic Analysis

Galloway, William E.Jackson School of GeosciencesDepartment of Geological SciencesThe University of Texas at AustinAustin, Texas 78712e-mail: [email protected]

Sylvia, Dennis A.Jackson School of GeosciencesThe University of Texas Institute for Geophysics4412 Spicewood Springs Rd.Austin, Texas 78759e-mail: [email protected]

AbstractSequence stratigraphic application has emphasized

the recognition and use of subaerial (fluvial entrenchment)or shallow marine/shoreface (regressive ravinement) sur-faces as critical boundaries for defining sequences. Thesesurfaces are variously objectively or conceptually associatedwith times of onset, maximum rate, and/or lowest position ofrelative sea level fall. However, well-dated Quaternary ana-logues demonstrate that the fluvial entrenchment surface isneither inherently synchronous nor regional, and that low-stand facies associations and their bounding surfaces arehighly dependent upon the vagaries of paleogeography andsediment supply. Furthermore, some basin fills displaystratigraphy in which demonstrable subaerial or ravinementsurfaces correlative to fall events are poorly preserved orentirely lacking, but in which sequences can be defined by

use of various combinations of transgressive ravinement,marine deflation, and marine starvation surfaces. These sur-faces may not and need not correspond to a relative fall (orrise) of sea level. Selection of stratigraphic surfaces assequence boundaries and interpretation of sequence systemstract compositions and relationships both require under-standing of the overall depositional systems tract and of thefull array of regime variables: sediment supply, sedimentcomposition, base level change, and energy regime. Func-tional, reproducible, and chronostratigraphic “… geneticallyrelated successions of strata bounded by unconformities ortheir correlative conformities…” can be defined, correlated,mapped, dated, and interpreted through the use of a varietyof regional stratigraphic surfaces of non-deposition anderosion.




Genetic Stratigraphy, Stratigraphic Architecture,and Reservoir Stacking Patterns of the Upper Miocene—Lower

Pliocene Greater Mars–Ursa Intraslope Basin, Mississippi Canyon, Gulf of Mexico

Meckel, Lawrence D., IIIUgueto, Gustavo A.Lynch, H. DavidCumming, Earl W.Hewett, Ben M.Bocage, Eric J.Shell Exploration & Production Company701 Poydras StreetNew Orleans, Louisiana 70139

Winker, Charlie D.Shell Technology EPBellaire Technology CenterPO Box 481Houston, Texas 77001

O’Neill, Brian J.Shell Deepwater Services701 Poydras StreetNew Orleans, Louisiana 70139

Abstract

The late Miocene–early Pliocene sediments of thenorthern greater Mars-Ursa intraslope basin in the Gulf ofMexico record high-resolution (ca. 0.5 Ma) cyclic depositionof couplets of deep water fan lobes (sheet sands) and chan-nelized or amalgamated systems bounded by local to regionalcondensed sections. Internally, the sheet sand and channel-ized systems are separated by a transitional surface of bypass,avulsion, and/or erosion. These fourth-order cycles are thebuilding blocks that make up third-order seismic faciesassemblages, which in turn record the progressive fill andspill sedimentary dynamics in salt-withdrawal minibasins.

Third-order sequences in the greater Mars-Ursaintraslope basin reflect regional variations in accommoda-tion and sediment supply. The rate of deposition of an older(10.0–7.0 Ma) third-order assemblage is significantly greaterthan that of a younger (7.0–4.2 Ma) assemblage. The olderassemblage has a greater abundance of thick, laterally exten-sive sheet sands and a higher composite net-to-gross ratiothan the younger assemblage, which contains more amal-gamated and bypass channels and associated over bankfacies, and has a lower composite net-to-gross.

Fourth-order cycles display compensational stackingpatterns in which the overlying channel system is best devel-oped where the sheet sand system is thin or not present. The

fourth-order stratigraphy of the basin is controlled by highfrequency variations in accommodation and sediment sup-ply. Eustatic changes affect the supply of sediment from theshelf to the slope, but they are not a primary control in theformation of fourth-order deepwater sequences.

Condensed sections that bound the fourth-ordercycles are deep marine (pelagic) mudstones that drapetopography. They occur in association with faunal abun-dance and diversity peaks and often correspond to abruptchanges in incremental overpressure. Because they representperiods of minimum relative sedimentation rates and maxi-mum relative rates of accommodation creation, basinmargins have their highest relief at the ends of these periods.Several of the condensed sections are interpreted to correlateto maximum flooding events on the shelf.

Thick, high net-to-gross fan lobes that occur abovethe condensed sections have been deposited as sedimenta-tion rates in the basin increased. They fill paleo-topographiclows and onlap abruptly against high-relief basin margins.Deep water faunal abundances in these sections are at rela-tive minima due to the influx of sediment, and in someinstances, the sands have a biofacies signature indicative ofreworking. However, a lack of corresponding increases in


either terrigenous content or reworked Cretaceous materialsuggests a local source for these reworked sands.

Subtle transitional surfaces separating the sheets andchannels are identified by the onset of apparent paleo-bathy-metric deepening at the bases of faunal abundance anddiversity peaks. Typically, these surfaces document intra-basinal avulsion or erosion and sediment bypass, caused byinfill of available accommodation by sheet sands.

The channelized systems or amalgamated channel/

sheet systems that overlie transitional surfaces are associated

with decreasing rates of sedimentation and low rates of cre-

ation of accommodation. Thin, laterally restricted

amalgamated channels and sheet deposits may accumulate

in the limited accommodation. If present, erosional channels

and bypass scours are filled by sand.


Allostratigraphy Versus Sequence Stratigraphy

Bhattacharya, Janok P.Geosciences, University of Texas at DallasP.O. Box 830688, FO21Richardson, Texas 75083-0688e-mail: [email protected]

AbstractAllostratigraphy is the only means available for for-

mally naming stratigraphic units defined on the basis ofobserved bounding discontinuities. Sequence stratigraphyrepresents a powerful way of interpreting allostratigraphicunits in the context of cyclic changes in accommodation andaccumulation. Lack of consistency in definition and usage ofsequence terms, however, shows that it is premature as ameans of formal naming. Sequence stratigraphic terms areinconsistent in that they may convey either positional or tem-poral concepts. For example, many sequence stratigraphers'reveal their temporal bias by referring to early and late sub-division within “systems tracts,” despite claims that"systems tracts" are defined purely physically. Sequencestratigraphic terminology also emphasizes that units aregenetically related by a particular process. For example,sequence boundaries are defined as unconformities, andtheir correlative conformities, that show evidence of sub-aerial exposure. Marine discontinuities, although highly

useful for allostratigraphic correlations, do not satisfy thisstrict definition of a sequence boundary. In addition, thereare significant practical problems in defining a sequenceboundary where it is expressed wholly as a correlative con-formity. This potentially limits the ability to definesequences in areas where evidence for an unconformity maybe cryptic or absent. The bias towards subaerial exposure hasresulted in confusion in the interpretation of tectonicallyproduced marine erosion surfaces in the Cretaceous Seawayof North America. Marine erosion may remove evidence ofprior subaerial exposure, which must then be inferred ratherthan observed. Allostratigraphy is inherently more practicalin that it emphasizes mappable, observable discontinuities,rather than inferred exposure surfaces. Until the terminologi-cal confusion in sequence stratigraphy has been mopped-up,it must remain a highly valuable tool for interpretation but aless valuable tool for formally naming rock units.



Transgressive-Regressive (T-R) Sequence Stratigraphy

Embry, Ashton F. Geological Survey of Canada Calgary, Alberta, Canada, T2L 2A7e-mail: [email protected]

AbstractA sequence, as originally defined by Sloss and col-

leagues, was a stratigraphic unit bounded by subaerialunconformities. Such a stratigraphic unit proved to be oflimited value because, in most instances, sequences could berecognized only on the margins of a basin where subaerialunconformities were present. Vail and colleagues greatlyexpanded the utility of sequences for basin analysis whenthey redefined the term as a unit bounded by unconformitiesor correlative conformities. The addition of correlative con-formities allowed a sequence to potentially be recognizedover an entire basin.

This revised definition has led to the formulation offour different types of sequences, each having a different setof bounding surfaces. Vail and colleagues have defined twotypes: a type 1 depositional sequence and a type 2 deposi-tional sequence. A type 1 depositional sequence utilizes asubaerial unconformity as the unconformable portion of theboundary and a time line equivalent to the start of base levelfall for the correlative conformity. Because the subaerialunconformity migrates basinward during base level fall,much of it is therefore included within such a sequencerather than being on the boundary. Also it is impossible toobjectively recognize a time line that corresponds to the startof base level fall. For these reasons a type 1 depositionalsequence has little practical value.

A type 2 depositional sequence also uses the subaerialunconformity as the unconformable portion of the boundarybut uses a time line equivalent to the end, rather than thestart, of base level fall for the correlative conformity. This

resolves the problem of including a portion of the unconfor-mity inside the sequence. However, it is essentiallyimpossible to objectively recognize a time line that corre-sponds with the end of base level fall (start of base level rise)and thus this type of sequence also has no practical value.Galloway proposed the use of maximum flooding surfacesas sequence boundaries and named such a unit a geneticstratigraphic sequence. This alleviated the problem of majorsubjectivity in boundary recognition because maximumflooding surfaces can be determined by objective scientificanalysis. However, this sequence type founders on the prob-lem that the subaerial unconformity occurs within thesequence and thus it lacks genetic coherency on the basinmargins.

To overcome these major deficiencies in sequencedefinition, Embry and Johannessen have defined a fourthtype of sequence that they term a T-R sequence. Thissequence uses the subaerial unconformity as the unconform-able portion of the boundary and the maximum regressivesurface as the correlative conformity. This methodologykeeps the subaerial unconformity on the boundary and alsoprovides for a correlative conformity that can be objectivelydetermined. It thus avoids the fatal flaws of previouslydefined types. A T-R sequence can be divided into a trans-gressive systems tract below and a regressive systems tractabove by using the maximum flooding surface as a mutualboundary. T-R sequence stratigraphy, unlike the other pro-posed methodologies, has maximum practical utility with aminimum of stultifying jargon.



Transgressive-Regressive Cycles: Application to Petroleum Exploration for Hydrocarbons Associated with Cretaceous Shelf

Carbonates and Coastal and Fluvial-Deltaic Siliciclastics, Northeastern Gulf of Mexico

Mancini, Ernest A.

Puckett, T. Markham Center for Sedimentary Basin StudiesDepartment of Geological SciencesBox 870338The University of AlabamaTuscaloosa, Alabama 35487-0338e-mail: [email protected]: [email protected]

Abstract

Stratigraphic analysis of sedimentary basins is criticalfor correlation in a basin, for reconstructing the geohistoryof a basin, and for developing a successful petroleum explo-ration strategy for a basin. In studying only the shelfal areasof basins that are characterized by carbonate or mixed car-bonate and siliciclastic deposition and in which stratalpatterns are driven by low-frequency, tectonic-eustaticevents, a stratigraphic analysis based on the cyclicityrecorded in the strata (transgressive-regressive cycles) hasutility for correlation, for geohistory interpretation, and informulating petroleum exploration strategies. This is thecase for the Cretaceous section in basins of the northeasternGulf of Mexico.

In utilizing the concept of transgressive-regressive(T-R) cycles, eight T-R cycles are recognized in Cretaceous(upper Valanginian to lower upper Maastrichtian) strata ofthe northern Gulf of Mexico. The cycles consist of a trans-gressive (aggrading and backstepping) phase and aregressive (infilling) phase. These T-R cycles are useful forintrabasin correlation of Cretaceous strata in the Mississippiinterior salt basin and for interbasin correlation of Creta-ceous strata in the Mississippi interior salt basin and the EastTexas salt basin. Six regional Cretaceous unconformities andassociated hiatuses (late Valanginian, middle Cenomanian,

late Turonian to middle Coniacian, middle Campanian, lateCampanian to early Maastrichtian, and late Maastrichtian)and nine regional transgressive events (early Aptian, earlyAlbian, middle Albian, early Cenomanian, late Cenomanianto early Turonian, late Santonian, early middle Campanian,early late Campanian, and early Maastrichtian) have beenidentified as major events in the geohistory of these basins.

Hydrocarbon production from Cretaceous reservoirsin the northeastern Gulf of Mexico can be categorized as tothe phase of T-R cycles. Sandstone reservoirs associatedwith the early transgressive aggrading phase have accountedfor 42% of the 7.437 TCF of natural gas produced from Cre-taceous reservoirs in this region. Sandstone reservoirsassociated with the late transgressive backstepping andregressive infilling phases have accounted for 63% of the 2BBO produced from Cretaceous reservoirs in this region.These findings indicate that the primary natural gas explora-tion target in the northeastern Gulf of Mexico should beCretaceous sandstone reservoirs of the transgressive aggrad-ing phase of T-R cycles and that the principal oil explorationtarget in this region should be Cretaceous sandstone reser-voirs of the transgressive backstepping and regressiveinfilling phases of T-R cycles. These exploration targets areassociated with structural traps related to salt movement.




Keeping Pace: Continental (Nonmarine) Sequence Stratigraphy in a High Accommodation-Sediment Supply Regime,

Hornelen Basin (Devonian), Norway

Anderson, Donna S.Department of Geology and Geological EngineeringColorado School of MinesGolden, Colorado 80401e-mail: [email protected]

AbstractCyclic alluvial fan, braid plain, and lake deposits in a

study area in the north-central Hornelen basin of west-cen-tral Norway yield insights into the formation of sequenceboundaries and condensed surfaces in a high accommoda-tion-sediment supply setting. Examination of faciesarchitecture at two critical stratigraphic positions (times)within three large-scale cycles (sequences), the time of max-imum basinward progradation of the orthogonally sourcedalluvial fan and braid plain facies tracts and the time of max-imum flooding across the basin, shows little erosion and

sediment starvation, respectively. Hence, two key strati-graphic surfaces, sequence boundaries and condensedsections, do not form. In addition, the systems-tract configu-ration, while readily recognizable, becomes modified by thelack of regional erosion during sequence-boundary forma-tion: a volumetrically displaced lowstand systems tract doesnot form. In this basin, high sediment supply keeps pacewith high tectonic subsidence, creating an aggradational yetcyclic stratigraphic architecture.



Bounding-Surface Hierarchies and Related Sources of Heterogeneity in Seemingly Uniform Fluvial Sandstone Sheets

Holbrook, John Department of GeosciencesSoutheast Missouri State UniversityCape Girardeau, Missouri 63701e-mail: [email protected]

Oboh-Ikuenobe, Francisca E. Department of Geology and GeophysicsUniversity of Missouri, RollaRolla, Missouri 65409

AbstractFluvial sandstone sheets may appear uniform initially,

but detailed examination tends to reveal sharp lithologic con-trasts across bounding surfaces. The mid-Cretaceous MuddySandstone of southeast Colorado, USA contains two sand-stone sheets and provides examples of such potentialpermeability barriers. Sediment bodies bound and respectivebounding surfaces are, in order of ascending rank: bar and

dune deposits (1st- to 3rd-order), nested channel fills (4th-

order), channel fills (5th-order), channel belts (6th-order),

nested valley-fills (7th-order), valley-fills (8th-order), and

sequences (9th-order). Bar and dune through channel-beltdeposits commonly have permeability barriers because the

episodes of waning flow common to their deposition tend tocause draping of surfaces and filling of scours locally withfiner grained deposits. Channel-fills through sequences tendto have permeability barriers related to juxtaposition of per-meable and non-permeable lithofacies during successiveincision-and-fill events. Fluvial sandstone sheets can havereduced permeability in paleodip orientation that operates onthe scale of individual wells because of draping of down-dip-oriented bar- and dune-accretion surfaces. A dip-ori-ented grain, reducing permeability in the strike direction,may arise on the scale of fields, because of permeability bar-riers formed at nested channel through higher-order valleyand sequence boundaries.



Predictable Variations in the Marine Stratigraphic Record of the Northern and Southern Hemispheres and Reservoir Potential

Perlmutter, Martin A.ChevronTexacoILT/ERTC4800 Fournace Place, Ste. W502Bellaire, Texas 77401e-mail: [email protected]

Plotnick, Roy E.Department of Earth and Environmental SciencesUniversity of Illinois at Chicago845 W. Taylor St.Chicago, Illinois .60607e-mail: [email protected]

AbstractVariation in the phase relationships of precession-

scale sediment yield cycles and glacioeustatic cycles maycause systematic differences in the marine stratigraphy ofthe Northern and Southern Hemispheres. These differencesshould be evident in the variations in lithology, and bedthickness and distribution and therefore could impact theinterpretation of reservoir potential.

At precession-scale (~20 kyr), Northern and SouthernHemisphere insolation cycles are 180° out of phase. Conse-quently, similar climatic successions in oppositehemisphere, and associated sediment yield cycles can be180° out of phase, as well. Prior to the Plio-Pleistocene, thecommon glacial condition was a unipolar icecap. Under thiscondition, precession-scale eustasy will tend to track theinsolation cycle of the glaciated hemisphere. The result is

that similar climatic successions in opposite hemisphereswill have yield cycles with distinctly different phase rela-tionships to glacioeustasy. Such differences should not existin an ice-free world.

By taking these variations into account, stratigraphicinterpretations will improve, reducing uncertainty associatedwith exploration analyses. Further, by determining whichregions will be prone to maximum sediment yield at low-stands, the regions that are prone to the development of sandrich submarine fans could be high graded. This approachmay also lead to a more complete understanding of the pale-oclimate record by being able to determine whether aparticular interpreted sea level shift occurred as a result ofglaciation, or a more local forcing agent.




Depositional Topography: Key Element of Stratigraphic Interpretation and Panacea for Log Correlation; Part 1: Concepts

and Transitional Icehouse-Greenhouse Systems

Tinker, Scott W.Kerans, CharlesBureau of Economic GeologyThe University of Texas at Austin

Abstract

In any modern or ancient carbonate setting, one depo-sitional environment eventually transitions into another, andfacies change. Topography is a primary driver of lateralfacies change. In a given shelf or ramp profile, carbonatefacies tend to be more continuous along strike and more aptto change along dip. If topographic dip is steep, facieschange in shorter distances than if topographic dip is grad-ual. Because facies (1) dictate original petrophysicalproperties and strongly influence diagenetic alteration, (2)strongly influence petrophysical properties and associatedwireline log and seismic responses, and most importantly (3)change within a time-bound package of rock, it is highlyunlikely that the correlation of similar wireline log signa-tures or the tracing of a continuous seismic reflector forgreat distances will result in an accurate chronostratigraphicinterpretation.

Although these concepts are widely understood andaccepted today, and in spite of ever-improved seismic imag-ing technologies, accomplishing the feat of building realisticdepositional topography into subsurface stratigraphic inter-pretation remains a difficult task. Even though sequencestratigraphy has revolutionized both exploration and exploi-tation in the oil industry by showing that chronostratigraphyimproves the ability to predict the 3D distribution of reser-voir, source, and seal strata, stratigraphers continue to hedgebets towards flat correlation by correlating similar log signa-tures and carrying continuous seismic reflectors.

The only way to avoid this tendency toward thehorizontal is to impose a facies-driven model of depo-sitional topography onto the stratigraphic interpreta-tion. An accurate assessment of depositionaltopography requires a sedimentologic analysis of coreand outcrop analog data to determine reasonable water-depth ranges for component facies, and the definitionof a hierarchy of stratigraphic cyclicity to determinelonger term water-depth variation represented by com-ponent facies. Concepts of depositional topography areapplied differently for each high-frequency cycle(cycle) as follows:

1. Constructional cycle—Individual cycles shouldillustrate depositional topography that representsthe water depth of the included facies (i.e., if acycle contains a range of facies from tidal flatthrough 100-ft-water-depth outer ramp facies,then the bounding surfaces should illustrate thattopography). Because of the relatively short timeduration represented by an individual cycle, eachcycle should allow reconstruction of paleo-bathymetry once compaction/subsidence areremoved.

2. Draped cycle—High-frequency cycles that drapepreexisting topography will not necessarily showa simple facies to predicted water-depth correla-tion.

3. Conformable high-frequency sequence (HFS)boundaries—are a composite stratigraphicrecord of short-term and long-term eustasy, sub-sidence, sedimentation rate, and compaction, andtherefore may not show a direct relationship tofacies that are found directly below them but willnonetheless control depositional topography ofthe facies in the overlying sequence.

4. Disconformable (erosional) HFS boundaries—are not candidates for reconstruction of deposi-tional topography of the underlying facies, butlike conformable HFS boundaries, they will con-trol depositional topography of the facies in theoverlying sequence.

Permian-age outcrops and subsurface datasets fromWest Texas and New Mexico, representing transitional ice-house-greenhouse systems, provide an excellent startingpoint to illustrate the importance of depositional topographyon stratigraphic interpretation. Eustatic amplitude in transi-tional icehouse-greenhouse systems was neither too greatnor too small, but just right to record a relatively completestratigraphic signal along the depositional profile. Examplesinclude ramp to steep-rimmed profiles.


Depositional Topography: Key Element of Stratigraphic Interpretation and Panacea for Log Correlation Part 2: Concepts

and Transitional Icehouse-Greenhouse Systems

Kerans, CharlesTinker, Scott W.Bureau of Economic GeologyThe University of Texas at Austin

Abstract

In any modern or ancient carbonate setting, one depo-sitional environment eventually transitions into another, andfacies change. Topography is a primary driver of lateralfacies change. In a given shelf or ramp profile, carbonatefacies tend to be more continuous along strike and more aptto change along dip. If topographic dip is steep, facieschange in shorter distances than if topographic dip is grad-ual. Because facies (1) dictate original petrophysicalproperties and strongly influence diagenetic alteration, (2)strongly influence petrophysical properties and associatedwireline log and seismic responses, and most importantly (3)change within a time-bound package of rock, it is highlyunlikely that the correlation of similar wireline log signa-tures or the tracing of a continuous seismic reflector forgreat distances will result in an accurate chronostratigraphicinterpretation.

Although these concepts are widely understood andaccepted today, and in spite of ever-improved seismic imag-ing technologies, accomplishing the feat of building realisticdepositional topography into subsurface stratigraphic inter-pretation remains a difficult task. Even though sequencestratigraphy has revolutionized both exploration and exploi-tation in the oil industry by showing that chronostratigraphyimproves the ability to predict the 3D distribution of reser-voir, source, and seal strata, stratigraphers continue to hedgebets towards flat correlation by correlating similar log signa-tures and carrying continuous seismic reflectors.

The only way to avoid this tendency toward thehorizontal is to impose a facies-driven model of depo-sitional topography onto the stratigraphic interpreta-tion. An accurate assessment of depositionaltopography requires a sedimentologic analysis of coreand outcrop analog data to determine reasonable water-depth ranges for component facies, and the definitionof a hierarchy of stratigraphic cyclicity to determinelonger term water-depth variation represented by com-ponent facies. Concepts of depositional topography areapplied differently for each high-frequency cycle(cycle) as follows:

1. Constructional cycle—Individual cycles shouldillustrate depositional topography that representsthe water depth of the included facies (i.e., if acycle contains a range of facies from tidal flatthrough 100-ft-water-depth outer ramp facies,then the bounding surfaces should illustrate thattopography). Because of the relatively short timeduration represented by an individual cycle, eachcycle should allow reconstruction of paleo-bathymetry once compaction/subsidence areremoved.

2. Draped cycle—High-frequency cycles that drapepreexisting topography will not necessarily showa simple facies to predicted water-depth correla-tion.

3. Conformable high-frequency sequence (HFS)boundaries—are a composite stratigraphicrecord of short-term and long-term eustasy, sub-sidence, sedimentation rate, and compaction, andtherefore may not show a direct relationship tofacies that are found directly below them but willnonetheless control depositional topography ofthe facies in the overlying sequence.

4. Disconformable (erosional) HFS boundaries—are not candidates for reconstruction of deposi-tional topography of the underlying facies, butlike conformable HFS boundaries, they will con-trol depositional topography of the facies in theoverlying sequence.

Permian-age outcrops and subsurface datasets fromWest Texas and New Mexico, representing transitional ice-house-greenhouse systems, provide an excellent startingpoint to illustrate the importance of depositional topographyon stratigraphic interpretation. Eustatic amplitude in transi-tional icehouse-greenhouse systems was neither too greatnor too small, but just right to record a relatively completestratigraphic signal along the depositional profile. Examplesinclude ramp to steep-rimmed profiles.


Paleoclimate and the Origin of Middle Pennsylvanian Cyclothems (Fourth-Order Sequences) of North America

Cecil, C. BlaineDulong, Frank T.U.S. Geological SurveyReston, Virginia 20192e-mail: [email protected]: [email protected]

West, Ronald R.Department of GeologyKansas State UniversityManhattan, Kansas 66506e-mail: [email protected]

Edgar, N. TerenceU.S. Geological SurveySt. Petersburg, Florida 33710e-mail: [email protected]

AbstractTranscontinental correlations of a Middle Pennsylva-

nian fourth-order sequence provided evidence for therelative importance of allocyclic controls on the formation ofPennsylvanian cyclothems. These correlations (and relatedstudies) further indicated that eustasy was the primary con-trol on accommodation space in most basins, whereastectonic subsidence provided additional accommodationspace in a few basins. Temporal and spatial variations in cli-mate, however, were the primary controls on physical andchemical sedimentology. The climate model developedherein suggested that repetitive changes in rainfall patternsand surface winds at low latitudes were coincident with theglacial and interglacial intervals. During glacial intervals, alarge permanent high pressure cell was associated with asouthern hemisphere ice cap and a nearly stationary polarfront. The ice cap minimized annual (summer to winter)thermal variation in the atmosphere (sensible heating) overthe southern hemisphere land mass. As a result, permanenthigh pressure over the ice cap confined the intertropical con-vergence zone (ITCZ) to low latitudes, and a low pressurerainy belt (doldrums) developed in the equatorial region ofPangea during lowstands. During interglacials, the doldrumsbelt (low pressure belt) degenerated and was replaced byseasonal swings in the ITCZ, in response to seasonal sensi-ble heating of the atmosphere over both northern andsouthern hemisphere land masses. As a result, the climate inlow latitudes changed from relatively wet conditions duringglacial intervals to drier and more seasonal conditions duringinterglacial periods.

Paleoclimates in the eastern United States during gla-cial intervals are indicated by the following: (1) intense

chemical weathering of paleosols, (2) low fluvial sedimentsupply, (3) peat formation (now coal) during lowstands inresponse to a permanent low-pressure rainy belt and wetconditions, (4) deposition of black shale in basin centers dur-ing the early stages of transgression in response to low windspeeds and poor wind-driven circulation in epeiric seas priorto significant deterioration of the doldrums belt, and (5)transport, deposition, and preservation of eolian sediments(in basin margins) following a period of weathering of low-stand exposure surfaces (western United States).Paleoclimates during interglacial intervals are indicated byan influx of fluvial sediments as the doldrums belt disap-peared (eastern United States), and deposition of marinelimestone west of the Appalachian basin in response toincreased wind speeds and wind-driven circulation in epeiricseas coincident with highstands and maximum north-southswings of the ITCZ. All climatic factors (annual rainfall,seasonality of annual rainfall, wind speed, and wind direc-tion) have controlled sedimentation in cratonic depositionalenvironments as sea level rose and fell. Although tectonicsand eustasy control accommodation space, paleoclimatecycles (coincident with eustasy) control the lithostratigraphyof upper Middle Pennsylvanian cyclothems at any givenpaleo-latitude in the tropical regions of Pangea. Further-more, the present study negates “deep water” models for theorigin of Middle Pennsylvanian black shale and autocyclicmodels (delta plain, back barrier, or fluvial depositionalenvironments) for peat formation as precursors to Pennsyl-vanian commercial coal deposits.






Stratigraphic Architecture and Fundamental Sedimentology of Two Late Pleistocene Deltas: Gulf of Mexico and Indonesia

Roberts, Harry H.Coastal Studies InstituteLouisiana State UniversityBaton Rouge, Louisiana 70803

Sydow, JohnExploration Business UnitP.O. Box 714Port of Spain, Trinidad

Fillon, RichardEarth Studies Associate3730 Rue NicholeNew Orleans, Louisiana 70131

Kohl, BarryDepartment of GeologyTulane UniversityNew Orleans, Louisiana 70118

Abstract

The Mobile River shelf-edge delta, built on the outerMississippi-Alabama shelf, prograded to the shelf-slope breakas sea level approached the latest Pleistocene glacial maxi-mum. At the same time, the Mahakam River built a complexshelf-edge delta on the eastern shelf of Borneo (Indonesia).Both late Pleistocene deltas were constructed during falling-to-lowstand relative sea-level conditions. The former was fedby the temperate Mobile River, the latter by the equatorialMahakam River. Four coreholes provided detailed calibrationof high resolution seismic data for stratigraphic control withinthe Mobile River delta while one long corehole and numerouspiston and vibracores provided similar seismic calibration forstratigraphic control in the Mahakam delta. Systems tractsand key bounding surfaces were related to global eustacy inboth settings over ca. 125 ka.

Sequence architectures differ significantly, an impor-tant consequence of different depositional settings. Thenortheastern Gulf of Mexico is relatively stable, also withlow wave energy, but dominated by siliciclastic sedimenta-

tion. Falling-to-lowstand progradation of the Mobile River’sLagniappe delta has occurred in numerous overlapping andspatially offset lobes incised by a complex channel network.Clinoforms downlap the outer shelf shale directly overlyingan isotope stage 5 interglacial condensed section. By con-trast, the tropical Mahakam shelf is tectonically active, haslow wave energy, strong oceanic currents, upwelling, and amixed siliciclastic–carbonate depositional system. Falling-to-lowstand clinoforms of this delta downlap a highly irregu-lar surface of isolated and fused carbonate bioherms builtabove a transgressive surface that formed during the preced-ing sea level rise. Both the Mahakam and Mobile Riverdepocenters are multilobate and clearly built by autocyclicswitching of depositional sites. The eastern lobes of theMobile River delta show evidence of wave reworking whilethe western flank is fluvially dominated. Both the Mahakamand Mobile deltas are composed of sand-rich clinoforms andchannel deposits that possess excellent reservoir properties.


Sea-Level Estimates for the Latest 100 Million Years: One-Dimensional Backstripping of Onshore New Jersey Boreholes

Kominz, Michelle A. Van Sickel, William A. Western Michigan UniversityDepartment of GeosciencesKalamazoo Michigan

Miller, Kenneth G. Browning, James V. Rutgers, the State University of New JerseyDepartment of Geological SciencesPiscataway, New Jersey

AbstractBackstripping analysis of the Bass River and Ancora

boreholes from the New Jersey Coastal Plain (Ocean Drill-ing Project Leg 174AX) provided new Late Cretaceous sea-level estimates and tested previously published Cenozoicsea-level estimates. Amplitudes calculated from all New Jer-sey boreholes were based on new porosity-depthrelationships estimated from New Jersey Coastal Plain elec-tric logs. In most cases, amplitudes and duration of sea levelwere comparable when sequences were represented at multi-

ple borehole sites, suggesting that the resultant curves werean approximation of regional sea level. Sea-level amplitudesas great as 50 m were required by third-order Cretaceoussequences. Most amplitudes were probably closer to 20 to 40m. Third-order (0.5–3 m.y.) sea-level changes of Paleoceneand younger sequences were generally less than 30 m andwere superimposed on a long-term (= 100 m.y. duration)sea-level fall from a maximum early Eocene value ofapproximately 100 to 140 m.


ODP, Sequences, and Global Sea-Level Change:Comparison of Icehouse vs. Greenhouse Eustatic Changes

Miller, Kenneth G. Browning, James V. Wright, James D. Mountain, Gregory S.Hernández, John C. Olsson, Richard K. Feigenson, Mark D.Department of Geological SciencesRutgers UniversityPiscataway, New Jersey 08854

Kominz, Michelle A. Van Sickel, William A.Western Michigan UniversityKalamazoo, Michigan 49008-5150

Sugarman, Peter J. New Jersey Geological SurveyPO Box 427Trenton, New Jersey 08625

Abstract

Understanding eustatic (global sea-level)changes and their effects on the geological record is animportant but difficult task because eustatic effects arecomplexly intertwined with basin subsidence andchanges in sediment supply. Led by Peter Vail,researchers at EPR reconstructed a eustatic history byapplying sequence stratigraphy to a global array of pro-prietary seismic profiles, industry wells, and outcrops.This EPR eustatic record has been controversial owingto methodological concerns and reliance on largelyunpublished data. The Ocean Drilling Program (ODP)has focussed on drilling the New Jersey, Bahamas, andAustralian margins for sea-level studies and hasaccomplished the following:

1. Validated a transect approach of drilling passivecontinental margins and carbonate platforms(onshore, shelf, slope);

2. Tested and validated the assumption that the pri-mary cause of impedance contrasts producing

seismic reflections on continental margins arestratal surfaces including unconformities;

3. Proved that the ages of sequence boundaries onmargins can be determined to better than ±0.5m.y. and provided a chronology of eustatic low-ering for the past 100 m.y.;

4. Achieved orbital-scale (perhaps suborbital)stratigraphic resolution on continental slopes andcarbonate platforms;

5. Showed that siliciclastic and carbonate marginsyield correlatable and in some cases comparablerecords of sea-level change;

6. Evaluated the sedimentary response of both trop-ical and cool-water carbonate platforms toeustatic changes;

7. Begun to constrain the amplitude and cause ofeustatic change for both the Iceahouse World ofthe past 42 m.y. and the Greenhouse World of250-42 Ma, as outlined below.


Sequence Stratigraphy in Fine-Grained Rocks: Beyond the Correlative Conformity

Bohacs, Kevin M.ExxonMobil Upstream Research Company3120 Buffalo SpeedwayHouston, Texas 77098e-mail: [email protected]

Neal, Jack E. Grabowski, George J., Jr.ExxonMobil Exploration Company233 Benmar StreetHouston, Texas 77060-2598

AbstractMudrocks provide the source and seal of hydrocar-

bons and are key elements in reservoir models as baffles andbarriers. Sequence stratigraphy provides an excellent frame-work within which one can integrate the many scales ofphysical, chemical, and biological observations necessary tounderstand these rocks across the spectrum of depositionalsettings. Although flooding surfaces and depositional-sequence boundaries may be subtly expressed in mudrocks,they can be recognized through distinct changes observed incore, outcrop, well-logs, and on seismic data. Beyond thechronostratigraphic utility of the correlative conformity,abundant paleoenvironmental information is recorded infine-grained strata—depositional sequences do not just fadeaway into obscurity in distal reaches, but have objectiveattributes that allow extension of stratigraphic frameworksand play-element predictions over very large areas.

Flooding surfaces fundamentally record a criticalincrease in accommodation relative to sediment supply,commonly recorded in mudrocks by laterally extensiveaccumulations of authigenic and pelagic components, alongwith evidence of sediment starvation and low bottom-energylevels. Even in mudrocks, some may record minor erosion,reworking, and lag formation due to low sediment supply,

but all are marked by a significant decrease in advected clas-tic input—contrasting with sequence boundaries.

Depositional sequence boundaries record a criticaldecrease in accommodation relative to sediment supply,commonly accompanied by an increase in depositionalenergy or a significant change in sediment supply, or both,over hundreds to thousands of square kilometers in bothfine- and coarse-grained lithologies. This is recorded even infine-grained lithofacies by regional erosional truncationassociated with subsequent onlap, exposure, reworked fos-sils, decreased continuity at lamina to bedset scale, alongwith increased accumulations of advected clastics and fossilsor secular changes in biogenic lithology. All of theseattributes (except subaerial exposure) are observed in physi-cally correlative distal reaches of unconformities across theircorrelative conformities.

Interactions of sediment supply and accommodationwith pre-existing topography control the expression of depo-sitional sequences. Marine environments tend to have themost widespread, gradually varying facies tracts, whereasparalic facies tracts tend to be most localized and abruptlychanging. Lacustrine sequences vary according to lake-basintype and range from very similar to shallow-marine silici-clastic sequences to very dissimilar.



Sequence Stratigraphy and Eustatic Sea Level

Kominz, Michelle A.Department of GeosciencesWestern Michigan UniversityKalamazoo, MichiganUnited Statese-mail: [email protected]

Pekar, Stephen F. Lamont-Doherty Earth ObservatoryPalisades, New York 10964United States

AbstractA number of the basic assumptions are made regard-

ing the relationship between sequence stratigraphy, sequencearchitecture, water depth and sea-level change. Testing ofthese relationships is made particularly problematic as aresult of the recent and prevalent assertion that it is impossi-ble to obtain eustatic magnitudes from sequencestratigraphic data. While much qualitative data has beenamassed to define and corroborate the sequence model, weconsider the implications of rigorous quantitative estimatesof eustasy, derived directly from sequence data.

Two-dimensional backstripping of strata in asequence stratigraphic framework coupled with quantitativebenthic foraminiferal biofacies analyses has yielded quanti-tative estimates of the geometry and water depths of ancient,

prograding sequences at a sub-sequence level (Kominz andPekar, 2001). The data set is from Oligocene strata beneaththe New Jersey Coastal Plain. Borehole data, largely fromOcean Drilling Project Sites 150X and 174AX, providedexcellent recovery for quantitative estimates of age, lithol-ogy, compaction, and benthic biofacies (Miller et al., 1994,1996, 1997, and 1998).

Results indicate that in most cases sequence bound-aries are associated with a downward shift in sea level assuggested by most sequence models. Maximum floodingsurfaces generally occur at or near the maximum value ofsea-level rise. Finally, there is no consistent relationshipbetween clinoform breaks and water depth.



Clinoforms, Clinoform Trajectories and Deepwater Sands

Steel, Ron University of WyomingLaramie, Wyoming 82071e-mail: [email protected]

Olsen, Torben StatoilStavanger, Norway

AbstractSedimentary prisms build out from the margins of

most types of sedimentary basin where there is significantdifferential subsidence. Clinoforms are the large-scale (hun-dreds of meters), time-line expressions of discrete phases ofaggradation and accretion within these prisms. The sigmoi-dal clinoforms are surfaces of dynamic equilibrium that arecreated and maintained by sediment aggradation to formtopsets and then sediment by-pass through the topsets ontothe accreting deepwater slope and beyond (Swift andThorne, 1991). It is argued, on this basis, that the topset sur-face of such large-scale clinoforms is referred to as amorphological ‘shelf’ and that the upper rollover of the cli-noform is referred to as the ‘shelf-slope break.’ Suchfeatures form at the supply margins of many types of basinwhere there is a water depth of at least several hundredmeters and are not restricted to continental margins.

The geometry and internal architecture of individualclinoforms, or groups/sets of clinoforms, can be used to pre-

dict how sediment budgets have been partitioned betweenthe shelf and deepwater areas beyond the shelf break. Thearchitecture of individual clinoforms (time scale of several100ky), mainly the degree of shelf-edge incision and thedegree of slope disruption, can indicate whether or not sig-nificant volumes of sand have been delivered beyond theshelf margin. Another method of prediction makes use of the‘trajectory’ of the shelf margin on time scales of 1Ma ormore; i.e., how the break-of-slope of successive clinoformsstack with respect to each other. High-angle trajectories gen-erally imply preferential sediment storage on the shelf andcoastal plain, whereas low-angle or falling trajectoriesinvolve erosion and sediment by-pass to the deepwater slopeand basin floor. These concepts are illustrated from well-exposed clinoforms and clinoform sets within a shelf marginthat has migrated and accreted some 30 km during an inter-val of some 6 Ma, in the Central Basin of Spitsbergen.



Allocyclic and Autocyclic Processes as Primary Controls on the Stratal Architecture and Sedimentological Expression

of Depositional Systems from the BolivianSub-Andean Foreland Basin

Wagner, John B. Nexen Petroleum U.S.ADallas, Texas

Bhattacharya, Janok Department of Geosciences, University of Texas at DallasRichardson, Texas

Soegaard, Kristian Norsk HydroStavanger, Norway

Moiola, Richard J. Dallas, Texas

Coleman, James M. Coastal Studies Institute-LSUBaton Rouge, Louisiana

AbstractThe Madre de Dios Basin of Bolivia represents two

distinct phases of tectonic development that illustrate thelinked stratigraphic responses to a changing basin style. Thefirst phase associated with the Paleozoic is characterized asan intracratonic setting. The second, which began during thelate Mesozoic and persists today, is the development of theSub-Andean Foreland Basin. Hydrocarbons occur primarilywithin stratigraphic traps, potential reservoirs and seals arePaleozoic to Late Mesozoic in age.

Paleozoic depositional environments identified fromcore indicate major changes in climatic conditions haveoccurred and include fluvial/deltaic, eolian dune, coastalsabkha, and shallow marine carbonate facies. A Late Devo-nian marine source rock with total organic carbon (TOC)content of up to 18% also occurs within the basin. Creta-ceous age sediments contain an incised valley system of 10

to 15 kilometers in width and 300 meters in depth. Valley fillfacies represent low sinuosity, braided fluvial systems grad-ing upwards into estuarine muds. Terracing of the valleymargin formed in response to multiple cut and fill episodes(baselevel fluctuations) of valley formation. Recurrentmovements of basement involved fault blocks related tomigration of the advancing forebulge, controlled the locationand magnitude of valley incision and drainage incisementpatterns.

Large-scale variations in depositional environments,duration of geologic time (450 to 60 MY) represented by thestratigraphic section within a changing tectonic style, pro-vides the Madre de Dios Basin as an example of the processto response interplay between tectonics, eustasy, climate andsediment supply.


Influence of Paleotopography, Eustasy and Tectonic Subsidence: Upper Jurassic Smackover Formation, Vocation Field, Manila

Sub-Basin (Eastern Gulf Coastal Plain)

Llinás, Juan CarlosDepartment of Geological SciencesThe University of AlabamaBox 870338Tuscaloosa, Alabama 35487e-mail: [email protected]

AbstractThe sequence of deposition of the Upper Jurassic

Smackover Formation in updip marginal positions, north ofthe regional peripheral fault trend in the eastern Gulf CoastalPlain is the result of the combined effects of many variablesincluding paleotopography, eustasy, tectonic subsidence, andcarbonate productivity, which have been highly influencedby environmental conditions. Tectonic subsidence is identi-fied as a critical mechanism for the generation of theaccommodation space required for the accumulation of thickSmackover sections measured in wells located in areas asso-ciated with basement paleohighs that were elevated duringthe time of Smackover deposition.

This study focuses on Vocation Field located in south-western Alabama, in the eastern margin of the Manila sub-basin, along the western flank of the Conecuh ridge. Thestructure in Vocation Field is a Paleozoic basement highassociated with the Triassic/Jurassic rifting event. The reser-voir in the field is the Upper Jurassic Smackover Formation,which overlies siliciclastic deposits of the Norphlet Forma-tion in the margins of the structure and onlaps crystallinebasement rocks in updip positions. Based on core and thinsection descriptions, four subenvironments have been inter-preted for Smackover deposits: microbial reef complex,shallow lagoon, shoal complex, and sabkha-tidal flat. These

subenvironments define an overall aggradational to progra-dational shallowing-upward marine cycle developed in anevaporate-carbonate setting. The reef and shoal complexesare the main and potential petroleum reservoirs. Significantboundstone accumulations have been deposited on the north-eastern side of the basement structure due to restrictedenvironmental conditions that favored the establishment andgrowth of the microbial reefs in that area.

Smackover deposition in Vocation Field was initiatedas a result of a rapid relative sea level rise (transgressiveevent) that partially submerged the basement paleohigh andled to the development of microbial reef buildups on thenortheastern flank of the structure during the “catch–up”phase of the carbonate system. Changes in the depositionalenvironment and a decrease in the rate of relative sea levelrise initiated the “keep-up” phase characterized by theaggradation and finally progradation of shallow subtidal andperitidal sediments of the upper part of the SmackoverFormation.

According to the depositional model, the microbialboundstones are equivalent to the peloidal wackestones andlaminated carbonate mudstones of the middle Smackoveraccumulated in downdip areas having greater water depths.



Controls on Sequence Architecture in Lacustrine Basins—Insights for Sequence Stratigraphy in General

Bohacs, Kevin M.ExxonMobil Upstream Research Company3120 Buffalo SpeedwayHouston, Texas 77098e-mail: [email protected]

Neal, Jack E.Grabowski, George J., Jr.ExxonMobil Exploration Company233 Benmar StreetHouston, Texas 77060-2598

Reynolds, David J.ExxonMobil Upstream Research Company3120 Buffalo SpeedwayHouston, Texas 77098

Carroll, Alan R.Department of Geology and GeophysicsUniversity of Wisconsin-Madison1215 W. Dayton AvenueMadison, Wisconsin 53706

Abstract

The sequence-stratigraphic approach of evaluating ahierarchy of rock packages bounded by various surfacesworks very well in lake strata. The expression of deposi-tional sequences, however, varies as a function of lakedepositional system, just as shallow marine-carbonatesequences look different from shallow-marine-siliciclasticsequences. Contrasts among lake and marine systems makeit inappropriate to directly apply one unmodified marinesequence-stratigraphic model to all lake systems. Indeed,one lacustrine model is not applicable to all lake-basin types.

Contrasts of sequence expression among lake-basintypes arise from several key attributes: Lake level and sedi-ment supply are commonly linked closely in lake systems(most marine models assume no linkage); lake shorelinescommonly move basinward by a combination of prograda-tion and desiccation. In addition, the character of a lake isfundamentally controlled by the relative rates of potentialaccommodation change and supply of sediment+water, giv-

ing rise to three distinct lake-basin types: overfilled,balanced-filled, and underfilled.

These differences strongly influence the occurrence,distribution, and character of hydrocarbon source, reservoir,and seal lithologies. Sequence boundaries vary from non-existent or minimally developed, through extensive erosionand incised-valley formation, to large basinward shifts andwidespread exposure. Flooding surfaces are enhanced asthey are commonly coincident with decreased sedimentsupply.

Lowstands vary from aggradational stacks of basin-floor turbidite parasequences to basin-center evaporites sur-rounded by extensive desiccation surfaces. Transgressivesystems tracts vary from thin and shale prone to thick andcoarse-clastic prone. Highstand systems tracts range fromobliquely progradational clastic shoreline parasequences toaggradational carbonate shoreline parasequences.

Successful exploration and production in lake basinsrequires attention to these variations.



Contrasting Styles of Eolian, Fluvial, and Lacustrine Sequence Development: UK Southern North Sea

Sweet, Michael L. ExxonMobil Upstream Research CompanyP. O. Box 2189Houston, Texas 77252e-mail: [email protected]

AbstractA sequence stratigraphic framework for the Permian,

non-marine rocks of the southern North Sea was constructedby recognizing and correlating lacustrine transgressive sur-faces and maximum flooding surfaces and eolian and fluvialsequence boundaries. These surfaces and the stacking pat-terns of the rocks they bound were found to have markedlydifferent expressions in lacustrine-dominated areas towardsthe basin center as compared to the fluvially dominated sys-tems at the basin margin.

In the more distal reaches of this depositional systemthe elevation of the water table exerts the main control on thedevelopment of surfaces and facies architecture. Here, dur-ing lake lowstands, laterally extensive eolian sequenceboundaries record deflation down to the water table and thegrowth of eolian dune fields. These eolian deposits haveexcellent reservoir quality. Laterally extensive, lacustrinetransgressive surfaces overlain by poor reservoir quality

sabkha and lacustrine deposits record a shift to a wetter cli-mate and rising lake levels. Fields in this part of thedepositional system are characterized by sheet-like reservoirarchitecture with good lateral, but poor vertical connectivity.

In contrast, sequences nearer the tectonically active,western margin of the basin were marked by locally deepfluvial incision (up to 70 m). It was during the onset of laketransgression when gradients were steep and fluvial dis-charge was increasing that extensive fluvial incisionoccurred. Incised valleys were filled with a complex mosaicof eolian, fluvial and lacustrine facies. Lateral facies vari-ability is high, which reduces lateral connectivity andpredictability. These fluvial systems experienced diminish-ing competence during falling lake level. Eolian erosion ofolder sabkha and fluvial deposits and eolian deposition char-acterized lake lowstands.



Extracting Stratigraphic Information from 3D:Exploiting the Seismic Data

Liro, Louis M.Cline, KimberlyVeritas DGC Inc.10300 Town ParkHouston, Texas 77072 USA

AbstractWhereas seismic stratigraphy has its roots in the iden-

tification and delineation of depositional packages and theirbounding unconformities on seismic data, sequence stratig-raphy is primarily concerned with well log patterns andoutcrop geometry to evaluate sub-sequence packages. In this

paper, we discuss the identification of depositional packagesand stratigraphic elements from seismic volumes, utilizingnot just vertical sections of conventional amplitude data butalternative slice views, animations, and visualizationtechniques.


Cyclic Attributes on Seismic Data and Sequence Stratigraphy—New Criteria for Exploration, New Interpretation Styles

Radovich, Barbara J.Integrated Geophysics Corporation710 N. Post Oak Blvd., Suite 300Houston, Texas 77024e-mail: [email protected]

AbstractThe application of sequence stratigraphy on seismic

data has long centered about the process of interpretation ofseismic reflection geometries of onlap and downlap and thetying of well data to seismic. But in many basins, and espe-cially in deepwater areas, well data may be rare ornonexistent. Tying shelf sequences to basin sequences isoften impossible because of long distances, gaps in seismicdata and complex structures. The concept of aggradationcycles within sequence architectures offers new criteria forexploration and new ways to interpret the seismic data on 2Dand 3D datasets with modern visualization tools. Manipula-tion of seismic voxels and attributes become tools to studystratigraphy. The focus of seismic interpretation shifts fromfinding reflection geometries to finding cyclic vertical stack-ing patterns even if geometries are absent or subtle. Thisframework can give insight into the sediment delivery sys-tem of margins and to the aggradation of sediments in deepwater in areas of sparse or no geologic control. These criteriahave been applied for almost a decade to the offshore Nige-ria exploration areas and key discoveries have been madeusing these techniques. Other areas of application includeGulf of Mexico, the Northwest Shelf of Australia, offshoreBrunei, and Bangladesh.

The key criterion that guides the interpreter in thesesettings is the repetitive cyclicity of seismic reflectionattributes and seismic facies patterns. The most useful cyclicattribute are changes in seismic instantaneous amplitude andfrequency. Vertical stacking patterns of seismic attributes

can be utilized in much the way that well log curve stackingpatterns are used to guide sequence stratigraphy analysis.Cyclic seismic facies patterns often change upwards fromlaterally continuous reflections to subtle mounded patternsor chaotic patterns. The attribute cycles and succession of

seismic facies most often correlate to the 3rd-order sequenceand the different depositional energy and styles that predom-inate as sea level falls then rises. The key parameters thatchange through this cycle are bed thickness, lithology, faciesassemblages, and depositional styles such as sheet-forms orsinuous channel-forms. In deep water settings, these cyclesare often a very prominent feature of the seismic data. Fullanalysis of the seismic data from these areas typicallyreveals the framework on three scales; the mega-architecture

basin scale of 2nd-order sea level change and tectonic subsid-

ence, the 3rd-order “building block” sequence scale of manysea level falls and rises, and the parasequence scale suitablefor well prediction and reserve calculation. The repetitivenature of the cycles implies a time of balance for importantparameters like sedimentation rate, subsidence, sea level,and the development of a matured, efficient sediment deliv-ery system. These patterns also imply a high potential ofrecycled sediments stored in an intermediate position readyto be delivered efficiently to the basin at each lowstand ofsea level. Thus, the more repetitive the cycles, the better thepotential for good quality reservoir sands occurring in thedeepwater facies.



Oligocene/Miocene Depositional System,Volta Fan Fold Belt, Ghana

Nibbelink, K. A. Huggard, J. D. Devon Energy Corporation333 Clay Street, 10th FloorHouston, Texas 77002

AbstractInversion structures of the Volta Fan Fold Belt, Ghana

developed during the Upper Cretaceous in response to rightlateral strike slip movement along a restraining bend in theRomanche fault zone across the Keta Arch. The deposi-tional architecture of the Oligocene to Miocene deep watersandstone reservoirs was controlled by topography createdby the inversion structures and subsequent erosion duringthe Upper Oligocene, 30 my lowstand of sea level. Erosionat the 30 my sequence boundary cut 15 to 20 canyons acrossthe shelf. These canyons were cut 200 to 500 meters deep, 1to 2 km wide and provided a critical part of the sedimentdelivery system from the Volta River, across the shelf to thedeep water.

Amplitude patterns from 3-D seismic define the deep-water sequences that systematically fill the topographic

relief created by the Upper Cretaceous structural and Oli-gocene erosional events. Upper Oligocene to LowerMiocene sedimentation consists of 1) base of shelf fans atthe mouth of the shelf canyons, 2) ponded fans behind theinversion structures, and 3) basin floor fans in front of thesestructures. Middle Miocene fan systems are deposited in aback stepping succession with the larger fans on the flanksof the Keta Arch. During the Upper Miocene, a major pro-gradation of the shelf occurs and the deep water topographyis filled, which allows fan sedimentation across the entirearch. These Oligocene to Miocene deep water sandstones aswell as the deeper Upper Cretaceous sandstones should pro-vide excellent reservoirs for the developing hydrocarbonsystem in the Volta Fan Fold Belt.


Sequence Stratigraphic Framework forOil- and Gas-Prospective Brookian Turbidites,National Petroleum Reserve in Alaska (NPRA)

Houseknecht, David W.U.S. Geological Survey12201 Sunrise Valley Drive, MS 956Reston, Virginia 20192e-mail: [email protected]

Schenk, Christopher J.U.S. Geological SurveyDenver, Colorado

AbstractIntegrated field and subsurface studies of the Albian

Torok and Nanushuk formations (coeval clinoform andtopset couplet) have produced a sequence stratigraphicframework for identifying fairways most likely to containstratigraphic traps in Brookian turbidites in NPRA. Strati-graphic traps in the Torok involve lowstand, sand-richturbidite facies sealed by condensed mudstones depositedduring transgression. The lowstand deposits commonlydownlap onto, and interfinger basinward with, oil-pronesource rocks of the gamma-ray zone (GRZ), an Aptian-Albian condensed section.

Optimum reservoirs occur in amalgamated turbiditesdeposited in channels incised into mudstones of the mid-lower slope or in channel-levee systems on submarine fans;the former may grade downslope into the latter within a sin-gle stratigraphic trap. Reservoir potential also may occur in

backstepping fan lobes deposited during earliesttransgression.

At least 15 Albian shelf margins displaying lowstandsequence boundaries have been mapped in NPRA using pub-lic domain, 2-D seismic data. Shelf margins are generallyoriented north-south in northern NPRA and swing eastwardto parallel the Brooks Range in southern NPRA. Sedimentdispersal patterns and accommodation may influence thesize and distribution of potential stratigraphic traps in turbid-ite facies along these shelf margins. For example, depositionin distal parts of the sediment dispersal system combinedwith low accommodation may favor the occurrence of point-sourced, isolated lenses of turbidite facies in northernNPRA. In contrast, deposition in proximal parts of the sedi-ment dispersal system combined with high accommodationmay favor the occurrence of line-sourced, laterally coalesc-ing aprons of turbidite facies in southern NPRA.



Sequence and Seismic Stratigraphy of the Bossier Formation (Tithonian; Uppermost Jurassic), Western East Texas Basin

Klein, George D.SED-STRAT Geoscience Consultants, Inc.14019 SW Frwy.; Suite 301, PMB 335Sugar Land, Texas, 77478-3563e-mail: [email protected]

Chaivre, Kenneth R.Phillips Petroleum Co.North American Production6330 West Loop SouthBellaire, Texas, 77401e-mail: [email protected]

AbstractSequence and seismic stratigraphic analysis of well

logs and 2-D seismic lines from Freestone, Anderson, Leon,Houston, Madison, Robertson and Limestone Counties,Texas, demonstrates that the Bossier Formation of the west-ern East Texas basin can be subdivided into tworecognizable sequences separated by a major sequenceboundary (SB-2). Similarly, the Bossier Formation is alsobracketed by a basal (SB-1) and upper (SB-3) sequenceboundary separating it from the Gilmer (Cotton Valley)Lime of the Haynesville Formation below, and the CottonValley Sand above, respectively.

In seismic sections, the SB-2 boundary in the middleof the Bossier Formation was identified by tracing moundedbasal reflectors and sigmoid basal reflectors representingbasin floor and slope fans. This boundary was correlatedonto the shelf below deltaic sands. In well log sections, basinfloor fan log shapes were traced laterally into slope fan and

stacked delta log patterns to identify SB-2. These basin floorand slope fans immediately above the SB-2 boundary repre-sent a lowstand systems tract, whereas the lower Bossier(below the SB-2 Sequence Boundary) represents a transgres-sive systems tract and the upper Bossier (above the SB-2boundary) represents a prograding complex.

Burial history analysis suggests that the lower Bossieraccumulated during a time of rapid mechanical subsidencewhen the East Texas basin was underfilled. A drop in sealevel associated with the SB-2 boundary represents a majorclimate shift from tropical to cooler conditions, favoringrapid influx of sands from the ancestral Mississippi, Ouach-ita, and Red River systems. These sands developed innershelf prograding deltaic packages, outer shelf and incisedvalley fill stacked deltas, and basin submarine fan systems.The stacked deltas and basin fan sand systems all representprospective gas plays.




Continental Shelf Sand Ridges:Genesis, Stratigraphy and Petroleum Significance

Nummedal, DagInstitute for Energy Research, Department of Geology and GeophysicsUniversity of WyomingLaramie, Wyoming 82071-4068

Suter, John R.ConocoPhillipsP.O. Box 2189Houston, Texas 77252-2197

AbstractThe debate about the origin of sand ridges on modern

continental shelves that took place in the 70s and early 80s isnow repeating itself with respect to ancient ‘isolated shallowmarine’ sand bodies. A review of the multiple interpretationsof one such controversial sand body, the Upper CretaceousShannon Sandstone of Wyoming, conducted by Suter andClifton in 1999, concludes: “we cannot, as a result of ouranalysis, unequivocally disprove any of the interpretationsproposed for the Shannon, and we suspect that a collectiveinability to do so [...] is the fuel on which this controversyruns.”

A ‘paradigm shift’ is needed in shelf sand ridge stud-ies at this time, and it is this: shelf sand ridges are compositefeatures. The debate needs to move beyond arguing aboutthe implications of seemingly contradictory implications ofthe sedimentary structures, to one where the sedimentologyis constrained by precise stratigraphic architecture. Numer-ous studies of modern ridge fields demonstrate that theycommonly are separated from their substrate by a ravine-

ment surface, or by a marine erosion surface formed inswales between migrating ridges. It is also clear that thatmany shelf sand ridges contains cores, or ‘precursors’ ofshoreline deposits, the preservation of which is a function ofthe amount of migration of the ridge after its initial forma-tion at the shoreline.

Shelf sand ridges are potentially major hydrocarbonreservoirs. The cumulative oil production from the TocitoSandstone fields in the San Juan basin is about 160 MMBO;that from Shannon strata in the Powder River basin is evengreater. Hartzog Draw, which is dominantly a Shannon field,has an estimated 400 MMBO in place. Several Middle andUpper Miocene oil fields on the northwest Java shelf also areproducing from reservoirs interpreted as shelf sand ridges.

Controversy about outcropping shelf sand ridges willprobably continue for some time, because only small parts ofthe commonly composite ridges are available forexamination.


Amplitude Anomalies in a Sequence Stratigraphic Framework: Exploration Successes and Pitfalls in a Subgorge Play,

Sacramento Basin, California

May, Jeffrey A.EOG Resources, Inc. (formerly at DDD Energy, Inc.)

600 17th Street, Suite 1100NDenver, Colorado 80120

Przywara, Mark S.DDD Energy, Inc.

50 Briar Hollow Lane, 7th Floor WestHouston, Texas 77027

Mazza, Thomas A.Deceased (formerly at DDD Energy, Inc.)

Clark, RubleYuma Exploration & Production Co. (formerly at DDD Energy, Inc.)1177 West Loop South, Suite 1825Houston, Texas 77027

Dlouhy, JohnHettenhausen, RogerOXY U.S.A., Inc.P.O. Box 1002Tupman, California 93276-1002

Abstract The Sacramento Basin is part of the Great Valley, a

prolific hydrocarbon province that is the remnant of a LateMesozoic-Early Cenozoic forearc basin in California. Aseries of buried submarine canyons extend seaward from theeastern margin of the forearc. These “gorges” have formedduring multiple episodes of relative sea-level fall during theTertiary, truncating Late Cretaceous through Eocene marineand nonmarine sandstones. Mudstones dominate the canyonfill, creating lateral and top seals for numerous gasreservoirs.

The late Paleocene Meganos Gorge crosses a propri-etary three-dimensional (3-D) seismic survey where DDDEnergy and OXY U.S.A. jointly have drilled numerous gasdiscoveries. Five discoveries occur in fluvial-deltaic sand-stones of the Maestrichtian Mokelumne River Formationfrom traps beneath the Meganos Gorge, a configuration withwhich we have had 100% success. The key to this success isunderstanding the associated amplitude anomalies withintheir sequence stratigraphic and lithologic context.

Initially, we (1) identified all amplitude anomalies,(2) mapped the base Meganos Gorge sequence boundary,

and (3) mapped regional flooding surfaces within the high-stand Mokelumne River section, paying particular attentionto truncations beneath the sequence boundary. Two gasfields in the area are analogs for subcrop production fromthe Mokelumne River: McDonald Island Field (now used forgas storage), which has an estimated ultimate recovery(EUR) of ~184 billion cubic feet (bcf) of gas, and KingIsland Field, which has a EUR of ~11 bcf.

We next conducted amplitude-versus-offset (AVO)analyses for all lithologies that yield anomalously highamplitude signatures. We built a database for lignites, low-velocity mudstones, carbonate-cemented sandstones, andconglomerates, in addition to gas-charged sandstones.Finally, we risked our subgorge prospects based on AVOresponse, structural position relative to the canyon-basesequence boundary, and juxtaposition of lithologies acrossthe sequence boundary. The analytical steps used here can beapplied to the continued discovery of subcrop reservoirsassociated with other gorges in the Sacramento Basin, aswell as the search for hydrocarbons trapped beneath subma-rine canyons in deep-water basins worldwide.


Regional Facies Relationships and Sequence Stratigraphy of a Super-Giant Reservoir (Arab-D Member), Saudi Arabia

Handford, C. RobertsonStrata-Search, LLC10744 Chestnut Ridge RoadAustin, Texas 78726e-mail: [email protected]

Cantrell, Dave L.Geological Research and Development CenterSaudi AramcoDhahran 31311, Saudi Arabia

Keith, Thomas H.Southern Fields Characterization DepartmentSaudi AramcoDhahran 31311, Saudi Arabia

AbstractThe Late Jurassic (Kimmeridgian) Arab-D member

consists of complex facies associations and clinoform unitsthat make up the intrashelf Arabian basin and associatedplatform. A ramp borders the Arabian basin and extended>300 km from Abu Safah and Berri fields (offshore) in thenorth to the interior of Saudi Arabia. This basin encloses thelargest field in the world (Ghawar) as well as several othersupergiant fields (Qatif, Abqaiq and Khurais) fields, all ofwhich produce from the Arab-D member.

From bottom to top, the Arab-D member consists ofpredominantly mud/intraclast-, organic-, and grain-domi-nated facies associations, which generally record an overallshallowing upward history and a long-term base-level fall.However, we recognize numerous high-frequency sequenceson the basis of facies stacking patterns and regional correla-tions. Lime mudstones, which are common in the lowerArab-D, represent a sub-wave base (~100 ft), outer ramp set-ting. Interbedded intraclastic and oncolitic rudstonesrepresent storm-dominated tidal channel and algal bank

environments. Thick, amalgamated rudstones record base-level fall and storm-wave erosion of the firmground sub-strates. The upper Arab-D reservoir mainly consists of open-marine low-relief biohermal and biostromal limestones suc-ceeded by skeletal/peloidal and oolitic grainstones. Coral-stromatoroid facies have accumulated as sheets and localbuildups (10-20 ft of relief) during a major base-level risethat culminated with a bank margin centered in Abqaiq andnorthern Ghawar fields.

These organic-rich facies were laid down as backstep-ping, northward thickening buildups. Subsequent base-levelfall led to the deposition of several seaward stepping (south-ward), skeletal, peloid, and ooid grain shoal complexes,which have shingled or clinoform geometry. The youngestclinoforms stepped southward as base level fell and werefollowed by lowstand to transgressive, onlapping anhydriteunits that formed in a subqueous to desiccated salina, whichextended across the remnant Arabian basin and provide aregional seal.



Facies and Sequence Stratigraphy of the Abo Formation in the Kingdom Field Area, Terry and Hockley Counties, West Texas

D’Agostino, Anthony E.PGS Reservoir Consultants Inc.16010 Barkers Point Lane, Suite 550Houston, Texas 77079e-mail: [email protected]

Party, J. MichaelWagner & Brown, Ltd.P.O. Box 1714Midland, Texas 79702e-mail: [email protected]

AbstractStudy of conventional cores, well logs, and seismic

data in the Kingdom Field and other parts of the Abo shelfcomplex trend in eastern New Mexico and west Texas hasled to new concepts about the style of deposition and tech-niques for stratigraphic subdivision of the Leonardian AboFormation. The implications of paleogeographic restorationof the Abo shelf, combined with detailed description andinterpretation of conventional cores from nine wells in King-dom Field has resulted in the identification of four importantdepositional facies that have significant control on reservoircharacter. The facies are; Supratidal/Terrestrial (up-dip

and top seal), Intertidal (reservoir grainstones), PlatformInterior (reservoir barrier), and Shelf-edge (secondary res-ervoir). A fifth facies, Karst Breccia, is also defined. Thisstudy reveals that the most productive facies in KingdomField (and along the trend) is the intertidal facies (peloidgrainstones) not the shelf-edge facies (boundstone reef).High-resolution stratigraphic analysis combining Fischerplots, well-log cross-sections, and 3D seismic data showsthat at least three third-order sequence boundaries, associ-ated with exposure of the shelf and significant karsting, areintraformational in nature.




Sequence Stratigraphic Framework in a Humid Alluvial Fan Complex, Quiriquire Oil Field, Venezuela

Kong, FanchenRepsol YPF / Maxus Energy Corporation1330 Lake Robbins Dr. #300The Woodlands, Texas 77380e-mail: [email protected], GuillermoLukito, PujiantoRepsol YPFPaseo de La Castellana 2804ª Planta28046 Madrid, SpainSarkawi, IchsanRepsol YPF / Maxus Energy Corporation1330 Lake Robbins Dr. #300The Woodlands, Texas 77380

AbstractThe giant Quiriquire Shallow oil field is located in the

southeastern foothills of the Serrania del Interior in north-eastern Venezuela. The main reservoir interval, theQuiriquire Formation, consists of conglomerates and sand-stones deposited during 2.4-0.9 Ma in a humid alluvial fancomplex inter-fingered with axial fluvial systems. Sequencestratigraphic concepts are applied to interpret 3D seismicvolume to establish an accurate tectono-stratigraphic deposi-tional model for facies prediction. Sequence boundaryrecognition criteria are explored for humid alluvial fans.

Five regionally extensive erosional unconformitiesare recognized as sequence boundaries. Maximum fluvialflooding surfaces and correlatives are recognizable as con-tinuous high amplitude reflectors with overlying widetroughs. Each sequence may have rising base level, highbase level, and falling base level systems tracts. At least fivelevels of cyclicity are interpreted. The three higher levels are

controlled by intermittent tectonic events of hill uplift andbasin subsidence from southeast contraction in a clockwisewrench-fault setting. Episodic growth strata, stratal trunca-tions, and linear shale diapirs are associated with thesetectonic events. Smaller cycles appear associated with sedi-ment supply and climatic changes or autocyclic processes.

Analyses of seismic reflection facies, trace shapefacies, and various attributes reveal a general basinwarddecrease of conglomerates and sandstones and an increase ofshales. Alluvial-fluvial evolution shows a general northwardfluvial onlapping trend and two major alluvial fan prograda-tions, in which conglomerates and conglomeratic sandstonesprograde farther basinward. Analyzing and imaging alluvialand fluvial internal architectural complexity and vertical/lat-eral alluvial-fluvial boundaries plays a critical role in ourdetailed reservoir correlation and characterization.



Application of Sequence Stratigraphy in Production Geology and 3-D Reservoir Modeling

Howell, JohnSTRAT GroupDepartment of Earth SciencesUniversity of Liverpool4 Brownlow StreetLiverpool L69 3GP, U.K.

Present address: Geologisk InstituttUniversitetet i BergenAllegaten 4, N-5007 Bergen, Norwaye-mail: [email protected]

Flint, StephenSTRAT GroupDepartment of Earth SciencesUniversity of Liverpool4 Brownlow StreetLiverpool L69 3GP, U.K.

AbstractSequence stratigraphy provides a deterministic frame-

work for understanding facies and ultimately reservoirarchitecture. It provides a framework for building reservoirmodels based upon logical, testable geological principles.This framework allows prediction of connectivity of flowunits, distribution of major permeability barriers and system-atic changes in sand body architecture. Zonation of reservoir

models into genetically related packages of strata (such as

parasequences or systems tracts) allows zones to be popu-

lated with predictable facies trends. These facies then form

the basis for the distribution of petrophysical parameters

within the reservoir. Sequence stratigraphy also provides a

reality check for stochastic models.



Examples of Fluvial Stratigraphy in the Wilcox Group, Louisiana as Revealed by High-Resolution 3D Seismic Data

Phelps, Jeanne S. F.Pennant Exploration, L.L.C.1520 Eighth St.New Orleans, Louisiana 70115e-mail: [email protected]

Jee, Jonathan L., Ph.D., P.G.850 Wilkinson Trace, No. 183Bowling Green, Kentucky 42103

Fogarty, Michael A.Pennant Exploration, L.L.C.1520 Eighth St.New Orleans, Louisiana 70115

Phelps, R. DavidPhelps Geoscience Services5803 Canal Blvd.New Orleans, Louisiana 70124

AbstractHistorically, both 2D and 3D seismic data have

proven of limited value in petroleum exploration in the Wil-cox Group (Paleocene-Eocene) of central Louisiana.Modern, conventionally processed 3D seismic data are use-ful for general sequence stratigraphic interpretation (e.g.,delineation of sequence boundaries) but do not have the ver-tical and horizontal resolution required to image the detailsof fluvial-deltaic stratigraphic features used to identify sub-tle hydrocarbon traps. Our processing of existing 3D seismicdata, using propriety software algorithms, sufficiently

enhanced the seismic data resolution to make it an effectivetool for petroleum exploration in fluvial-deltaic strata.

The processed seismic data have been calibrated withgeological information and synthesized with previous strati-graphic interpretations of the Wilcox Group in the region.The high-resolution seismic data make recognizable subtlehydrocarbon trapping situations that result from sand pinch-outs and differential compaction. When integrated with thesubsurface data, it is possible to create a more detailed strati-graphic framework for use in a hydrocarbon explorationprogram.



Sequence Stratigraphic Framework for Prediction of Shallow Water Flow in the Greater Mars-Ursa Area, Mississippi Canyon

Area, Gulf of Mexico Continental Slope

Winker, Charles D.Shipp, R. CraigShell International EPP.O. Box 481Houston, Texas 77001

Abstract

Shallow water flows (SWF) occur when a well isdrilled underbalanced into near-surface, overpressuredsands. SWF has been one of the most problematic aspects ofdeep-water drilling operations in the Gulf of Mexico, caus-ing premature abandonment of many wells and expensivedelays in many others; total costs to the industry have beenestimated at hundreds of million dollars. In recent years,engineering solutions have been largely successful in pre-venting or managing SWF; nevertheless, it is still vital topredict both the depth of occurrence and degree of overpres-sure in near-surface sands. Seismic signatures of these sandsrange from ambiguous to invisible, and pressure predictionmethods from seismic moveout velocities are inconsistent.Therefore, the most practical prediction methods are basedon geologic and engineering data from previous wells andboreholes (>50 surface locations in southwestern Missis-sippi Canyon alone), including LWD logs, direct andindirect overpressure indicators, and drilling summaries. Tomake lateral predictions from these well data, a localsequence stratigraphic framework has been established,which utilizes overlapping conventional and high-resolution3D seismic surveys tied to a regional framework based on2D and 3D seismic data.

Occurrences of near-surface sands and their potentialfor overpressure on the Gulf of Mexico continental slope areintimately related to late Pleistocene sequence stratigraphyof the Mississippi delta and fan. This is best illustrated in theGreater Mars-Ursa Area (GMUA) and vicinity, site of theindustry’s greatest SWF-related losses. The base of the maintrouble zone in the GMUA is defined by a subregionalsequence boundary (SB) (~Globorotalia flexuosa, P1), typi-cally marked by a “soft shale” and in many minibasins (butnot in GMUA)) by an onlap surface. Interpretation of thepost-SB stratigraphy is complicated by numerous mass-transport complexes (MTCs) of diverse origin and by abun-dant gas-related amplitude anomalies.

Overlying the P1 SB is a basin-floor fan (BFF) sys-tem, informally known as the MC Blue Unit, ponded on theslope by subtle antecedent topography. This BFF is appar-ently contemporaneous with the last lowstand delta complexof the Mississippi (Stage 2 and possibly 4); the equivalentunit has not been identified on the Mississippi fan. The BFFis characterized by abundant, but highly discontinuoussands, typically in vertically separate pressure compart-ments. On high-resolution data, the seismic characterconsists of both layered, subparallel, high-amplitude faciescontaining small channels and chaotic, high-amplitudefacies produced by local MTCs; at least four MTCs withinthe BFF have been identified at the Ursa field alone.

The BFF, composed of the MC Blue Unit, is overlainby a slope fan (SF) complex comprising a succession of fourcanyon-channel-levee systems (named Ursa, SouthwestPass, Old Timbalier, Young Timbalier), numerous mud-richMTCs, and hemipelagic mud. Some of these canyon systemscan be traced from incised valleys of the Mississippi Riveron the continental shelf to fan channels on the Mississippifan. Channel sands (massive to thick-bedded) and leveesands (thin-bedded) of the Ursa Canyon and Southwest PassCanyon (SWPC) have been penetrated in several locations.The SF-BFF boundary is obscured over much of GMUA,partly by channel incision, but more importantly by paired,channel-margin slides, which are most extensively devel-oped subjacent to SWPC. The SWPC channel-margin slidescomprise a 2-5 mile wide belt of rotated slide blocks dippingaway from the channel axis. The P1 SB typically serves asthe detachment surface for the SWPC slide complex; thisdetachment level is several hundred feet deeper than thechannel thalweg. The geometry of these slide complexesclearly indicates that they were triggered by channel inci-sion. Similar slide complexes occur on the Mississippi fan,where they have previously been misinterpreted as MTCspredating their corresponding fan channels.


Multiple Fields within the Sequence Stratigraphic Framework of the Greater Auger Basin, Gulf of Mexico

Dean, Michael C.Shell Exploration and Production CompanyP.O. Box 61933New Orleans, Louisiana 70161

Booth, James R.Brunei Shell Petroleum CompanySeria, KB3534Brunei Darussalam

Mitchell, Bruce T.Shell Exploration and Production CompanyHouston, Texas 77001-0576

AbstractThe greater Auger basin lies approximately 220 miles

south southwest of New Orleans, Louisiana in the deepwater Gulf of Mexico. Multiple exploration and develop-ment wells from five Shell producing fields in the greaterAuger basin have provided sequence stratigraphic informa-tion from several different basin settings and differentseismic facies (e.g., Prather et al., 1998). Two of these, theproximal Auger Field and the distal Macaroni Field havebeen used by Booth et al. (2000) to classify the overall seis-mic–stratigraphic framework of the basin. Additionaldrilling has provided information from three other fields totie into this framework. Shell’s producing fields in thegreater Auger basin are Auger, Cardamom, Macaroni, Oreg-ano, and Serrano. Though these fields lie within the samebasin-scale sequence stratigraphic framework, their deposi-tional settings vary considerably. Presently, the Auger saltdome, East Auger fault, and North Auger fault partition thegreater Auger bbasin into two sub-basins. At the time of

deposition of many of the producing reservoirs, these struc-tural features have manifested themselves in the form of thenorthwest-southeast trending Auger ridge. Macaroni, Oreg-ano, and Auger fields lie south of these structural features, inthe Auger basin proper and are primarily oil-bearing. Ser-rano and Cardamom lie northeast of these features in theAndros basin and are primarily gas bearing. The greaterAuger basin is an excellent case study for variations in thedeposition and preservation of reservoir quality sands inmultiple basin settings. Although the mechanisms differ indifferent settings, productive sands can be found in proxi-mal, distal, and lateral settings within the basin. In eachsetting, however, deposition is controlled both by sedimentsource and accommodation space. The reservoirs at OreganoField are healed slope deposits most similar to those atAuger Field; Serrano reservoirs are locally ponded depositssimilar to those at Macaroni Field; and Cardamom reservoirsappear to represent both healed slope and ponded deposits.


A Simple Methodology for Carbonate Sequence Stratigraphic and Seismic Stratigraphic Interpretation: Examples from the Lower

Cretaceous Section in Offshore Alabama and Mississippi

Badali`, MarcelloDepartment of Geological SciencesUniversity of AlabamaBox 870338Tuscaloosa, Alabama 35487e-mail: [email protected]

AbstractCarbonate sequence stratigraphic analysis requires a

different approach than siliciclastic sequence stratigraphicinterpretation. This paper provides a simple methodology forrecognizing and mapping third-order depositional sequencesusing a widely spaced dataset, integrating core data, well loginformation, and seismic data. The investigation of theLower Cretaceous carbonate section in offshore Alabamaand Mississippi is used as an example. A carbonate rimmedshelf margin, characterized by periodic siliciclastic sedimentinput, and the correlative slope, represent the Early Creta-ceous geologic setting in this area.

This study incorporates various kinds of data at dif-ferent scales. Approximately 3,500 kilometers of 2D multi-channel seismic reflection data are interpreted and integratedwith gamma ray, lithologic well-log descriptions, well-log

lithostratigraphic picks from more than 50 wells, and 527meters of core from wells in the study area and surroundingareas. Seven check-shot surveys have been used to integratethe seismic and well log data, and software for PC is used tointegrate and interpret the various data sets.

The interpretation includes several steps. The seismicattributes are first characterized, and then the seismic dataare interpreted without the support of the well-log and coredata. Once the main seismic sequence boundaries and sys-tems tracts are recognized, they are projected onto the well-log records. The core data are correlated with the well-logsignatures. The final interpretation includes the integrationof seismic, well-log, and core data in order to improve thepreliminary interpretation and to perform a sequence strati-graphic and seismic stratigraphic analysis.



Squinting Through Leaded Glass: A Public Domain View of the Alpine Play in the National Petroleum Reserve in Alaska (NPRA)

Houseknecht, David W.U.S. Geological Survey12201 Sunrise Valley Drive, MS 956Reston, Virginia 20192e-mail: [email protected]

AbstractThe 1994 discovery of the Alpine oil field (>400

MMBO recoverable), a subsequent Federal lease sale innortheast NPRA, and the 2001 announcement of discoveriesof commercial quantities of hydrocarbons in Alpine-typetraps within NPRA have reinvigorated exploration interest ina formerly moribund part of the Alaska North Slope. Lim-ited data available in the public domain suggest that keyingredients of Alpine-type accumulations include a highgravity oil charge apparently sourced from a condensed sec-tion in the Lower Jurassic and stratigraphic traps in theUpper Jurassic comprising a transgressive assemblage oflenticular, fine-grained, well winnowed shoreface sandsdeposited in erosional incisions and sealed by condensedmudstone.

Regional mapping of Jurassic depositional sequencesusing public domain, 2-D seismic and well data indicatesexcellent potential for extending the Alpine play westwardin the NPRA. Although the Upper Jurassic play extends

across the entire NPRA, the greatest potential may exist ineastern NPRA where a Lower Jurassic condensed section ispresent basinward (south) of a well defined shelf margin.Upper Jurassic depositional sequences offlap that shelf mar-gin and include thick clinoforms that downlap onto theLower Jurassic condensed section. Those clinoforms eithertoplap progradational shoreface sands or are truncated bysequence bounding unconformities or ravinements cappedby transgressive systems tracts that locally contain Alpine-type stratigraphic traps. From the Colville delta, this pro-spective depocenter trends southwestward for more than 100miles. However, play depths increase southwestward,thereby increasing the chances of reduced reservoir qualityand increased proportions of thermogenic gas.

Elsewhere in NPRA the apparent absence of both theLower Jurassic basinal condensed section and clear migra-tion pathways within Upper Jurassic strata may indicateincreased charge risk and lower resource potential.



Niger Delta Pleistocene Leveed-Channel Fans: Models for Offshore Reservoirs

Mitchum, Robert M.Consultant13039 PebblebrookHouston, Texas 77079e-mail: [email protected]

Wach, Grant D. ChevronTexacoHouston, TexasCurrent address: Dalhousie UniversityDepartment of Earth SciencesHalifax, Nova Scotia, B3J 3E5

AbstractThe youngest Pleistocene leveed-channel fans of the

Niger delta, offshore Nigeria, are defined by sea-bottomimages and shallow reflection patterns in 2-D and 3-D seis-mic surveys. They make excellent analogues for interpretingolder fans in the delta depocenter.

Niger delta structural trends control Pleistocene shelf,slope and basin depositional environments. The shelf marginis cut by canyons and gullies that are lowstand sedimentpaths to the basin. Upper slope areas, underlain by diapir andinner toe thrust structural trends, are zones of channel ero-sion and bypass. Lower slope areas, between the inner andouter thrust trends, contain leveed channels in local sags.They exhibit channel erosion and bypass in areas of activethrusts and tear faults.

The basin plain outboard of the outer thrust trend hasmajor deposition of large leveed channel complexes. The cen-

tral reentrant in the outer thrust trend is a major depocenter ofleveed channels fed through a larger canyon. The area to thefar northwest contains well-developed fans in the low areabetween the delta and the continental margin to the north.

A 3-D grid at the mouth of the large central canyonshows details of leveed channels deposited from the canyon.The first large sinuous channel was crevassed and aban-doned by a smaller, straighter distributary near the canyonmouth. Slumping and mass transport are important elements,and are intimately involved in and adjacent to the channelsystems.

The locations of fan complexes that comprise the deep-water depocenters appear directly related to the updip deltamorphology and progradation of the fluvio-deltaic system.



The Sequence Stratigraphy of the East China Sea: Where are the Incised Valleys?

Warren, Jeffrey D.Department of Geological SciencesUniversity of North Carolina at Chapel HillMitchell Hall, CB #3315Chapel Hill, NC 27599-3315e-mail: [email protected]

Bartek, Louis R., IIIDepartment of Geological SciencesUniversity of North Carolina at Chapel HillMitchell Hall, CB #3315Chapel Hill, NC 27599-3315e-mail: [email protected]

AbstractThe lowstand systems tract from the last glacial maxi-

mum (i.e., oxygen isotope stage 2; c. 14-24 ka) preserved onthe East China Sea continental margin is the only lowstandsystems tract during the Holocene and late Pleistocene (500ka to present) that exhibits major incision. Evidence of theseincised valleys is found in both present-day bathymetry andin seismic and chirp data. Older lowstand systems tracts,however, lack major incisive features on the inner and mid

shelf and exhibit laterally and vertically extensive (up to 300km and 60 m, respectively) packages of chaotic seismicreflections attributed to frequent fluvial avulsion. Incision inthese older lowstand systems tracts, where it does occur, isprimarily restricted to the outer shelf, however, it is not asso-ciated with knickpoint migration from the shelf-slope break,which remained submerged during even the lowestlowstands.




Oil Exploration Under the Catastrophist Paradigm

Wilson, James R.Holbrook, MarkJones, JimCentre for Future Technologies, Inc.722 S. MaurineIdaho Falls, Idaho 83401e-mail: [email protected]

AbstractThe uniformitarian paradigm, a key assumption in the

interpretation of the stratigraphic record, directs most of theoil exploration, making the history of discoveries a circularargument for this paradigm. However, a plot of giant oil fielddiscoveries shows interesting, nonrandom patterns that areinexplicable under current theory. The catastrophist para-digm explains these patterns and yields interesting insightsfor discovering future oil deposits.

Ninety percent of the giant oil fields (proven oil>500

million bbl or gas>3 Tcf) and ninety percent of the Large

Igneous Provinces (LIPs) are distributed along two great cir-

cles on the Earth. These great circles also intersect the

original sites of the craters of the three largest meteorites to

ever impact the Earth, suggesting that these patterns or

groupings were caused by these meteorites.



Ages of Maximum Flooding Surfaces and Revisions of Sequence Boundaries and Their Ages, Cenozoic to Triassic

Wornardt, Walter W. Jr.MICRO-STRAT INC.5755 Bonhomme, Suite 406Houston, Texas 77036713-977-2120e-mail: [email protected] Site: www.Micro-Strat.com

AbstractThe key to recognizing the third and fourth order dep-

ositional sequences is the maximum flooding surface. Anage designation of this surface is extremely important inseismic sequence stratigraphic analysis. Therefore, the pur-pose of this paper is to recognize and date the Cenozoic,Cretaceous, and Jurassic maximum flooding surfaces in Ma

and to assign a specific numerical age and letter designation

to each of these maximum flooding surfaces from the Juras-

sic to Recent. These numerical age designations are

proposed as a standard of reference for these maximum

flooding surfaces worldwide.


http://www.Micro-Strat.com

A-1 Program and Abstracts

Author Index

AAnderson, Donna S. 14Apps, Gillian M. 6

BBadali`, Marcello 44Bartek, Louis R., III 47Bhattacharya, Janok P. 11, 26Bocage, Eric J. 9Bohacs, Kevin M. 23, 28Booth, James R. 43Brown, L. Frank, Jr. 3Browning, James V. 21, 22

CCantrell, Dave L. 37Carroll, Alan R. 28Cecil, C. Blaine 19Chaivre, Kenneth R. 34Clark, Ruble 36Cline, Kimberly 30Coleman, James M. 26Cumming, Earl W. 9

DD’Agostino, Anthony E. 38Dean, Michael C. 43Delph, Bryan C. 6Dlouhy, John 36Dulong, Frank T. 19

EEdgar, N. Terence 19Embry, Ashton F. 12

FFeigenson, Mark D. 22Fillon, Richard 20Flint, Stephen 40Fogarty, Michael A. 41

GGalloway, William E. 8Grabowski, George J., Jr. 23, 28

HHandford, C. Robertson 37Hentz, Tucker F. 5Hernández, John C. 22Hettenhausen, Roger 36Hewett, Ben M. 9Holbrook, John 15Holbrook, Mark 48Houseknecht, David W. 33, 45Howell, John 40Huggard, J. D. 32

JJalfin, Guillermo 39Jee, Jonathan L. 41Jones, Jim 48

KKeith, Thomas H. 37Kerans, Charles 17, 18Klein, George D. 34Kohl, Barry 20Kominz, Michelle A. 21, 22, 24Kong, Fanchen 39

LLiro, Louis M. 30Llinás, Juan Carlos 27Loucks, Robert G. 3Lukito, Pujianto 39Lynch, H. David 9

MMancini, Ernest A. 13May, Jeffrey A. 36Mazza, Thomas A. 36Meckel, Lawrence D., III 9Miller, Kenneth G. 21, 22

A-222nd Annual Gulf Coast Section SEPM Foundation Bob F. Perkins Research Conference—2002

Mitchell, Bruce T. 43Mitchum, Robert M. 1, 2, 46Moiola, Richard J. 26Moore, Michael G. 6Mountain, Gregory S. 22

NNeal, Jack E. 23, 28Nibbelink, K. A. 32Nummedal, Dag 35

OO’Neill, Brian J. 9Oboh-Ikuenobe, Francisca E. 15Olsen, Torben 25Olsson, Richard K. 22

PParty, J. Michael 38Pekar, Stephen F. 24Perlmutter, Martin A. 16Phelps, Jeanne S. F. 41Phelps, R. David 41Plotnick, Roy E. 16Posamentier, Henry W. 4Przywara, Mark S. 36Puckett, T. Markham 13

RRadovich, Barbara J. 31Reynolds, David J. 28Roberts, Harry H. 20

SSangree, John B. 1, 2Sarg, J. F. (Rick) 7Sarkawi, Ichsan 39Schenk, Christopher J. 33

Shipp, R. Craig 42Snedden, John W. 7Soegaard, Kristian 26Steel, Ron 25Sugarman, Peter J. 22Suter, John R. 35Sweet, Michael L. 29Sydow, John 20Sylvia, Dennis A. 8

TTinker, Scott W. 17, 18Treviño, Ramón H. 3

UUgueto, Gustavo A. 9

VVail, Peter R. 1, 2Van Sickel, William A. 21, 22

WWach, Grant D. 46Wagner, John B. 26Warren, Jeffrey D. 47West, Ronald R. 19Wilson, James R. 48Winker, Charles D. 9, 42Woodall, Mark A. 6Wornardt, Walter W. Jr. 49Wright, James D. 22

YYing, Yudong (Don) 7

ZZeng, Hongliu 5

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