hydrocarbon migration and its near-surface

AAPG MEMOIR 66

HYDROCARBON MIGRATION AND ITS NEAR-SURFACE EXPRESSION Edited by Dietmar Schumacher and Michael A. Abrams

Downloaded from http://pubs.geoscienceworld.org/aapg/books/book/1308/chapter-pdf/3836849/9781629810812_frontmatter.pdfby gueston 18 August 2022

Cover photo: Streams of gas bubbles and oil droplets issue from the seafloor 540 m down, at a natural seep in the Gulf of Mexico. A gas hydrate deposit forms the central mound, which is about 50 cm in diameter and covered with a thin layer of sediment and bacterial mats. Chemosynthetic tube worms (LameMbrachia sp.) fringe the edges of the mound. Photo by Ian R. MacDonald.


Hydrocarbon Migration and Its Near-Surface

Expression Outgrowth of the AAPG Hedberg Research Conference Vancouver, British Columbia, April 24-28,1994

Edited by

D i e t m a r S c h u m a c h e r

M i c h a e l A . A b r a m s

A A P G M e m o i r 66

Published by The American Association of Petroleum Geologists

Tulsa, Oklahoma, U.S.A. Printed in the U.S.A.


C o p y r i g h t © 1996 The A m e r i c a n Association of Petroleum Geologists A l l Rights Reserved Published 1996

ISBN: 0-89181-345-4

A A P G grants permission for a single photocopy of an i t e m f r o m this publ icat ion for personal use. A u t h o r i z a t i o n for addi t iona l copies of items f r o m this publ icat ion for personal or internal use is granted b y A A P G p r o v i d e d that the base fee of $3.00 per copy is p a i d directly to the C o p y r i g h t Clearance Center, 222 Rosewood D r i v e , Danvers, Massachusetts 01923. Fees are subject to change. A n y f o r m of electronic or d i g i t a l scanning or other d i g i t a l t ransformation of port ions of this p u b l icat ion into computer-readable a n d / o r transmittable f o r m for personal or corporate use requires special permission f r o m , and is subject to fee charges by, the A A P G .

Association Editor: K e v i n T. Biddle Science Director: Richard Steinmetz Publications Manager: Kenneth M . W o l g e m u t h Special Projects Editor: A n n e H . Thomas Product ion: K a t h y and Dana Walker, Edi tor ia l Technologies, Renton, Washington

T H E A M E R I C A N ASSOCIATION OF PETROLEUM GEOLOGISTS

( A A P G ) DOES N O T ENDORSE OR R E C O M M E N D A N Y PRODUCTS

A N D SERVICES T H A T M A Y BE CITED, USED, OR DISCUSSED

I N A A P G PUBLICATIONS OR I N PRESENTATIONS AT EVENTS

ASSOCIATED W I T H A A P G .

This a n d other A A P G publications are available f r o m

A A P G Bookstore P.O. Box 979 Tulsa, O K 74101-0979 U.S.A. Tel (918)584-2555

or (800) 364-AAPG (U.S.A.—book orders only) Fax (918) 584-0469

or (800) 898-2274 (U.S.A.—book orders only) Tel 0225-445046 Fax 0225-442836

Bath B A 1 3JN U n i t e d K i n g d o m

U n i t 7, Brassmill Enterprise Centre Brassmill Lane

Geologica l Society P u b l i s h i n g House

A u s t r a l i a n M i n e r a l F o u n d a t i o n A M F Bookshop 63 C o n y n g h a m Street Glenside, South Austra l ia 5065 Austra l ia Tel (08) 379-0444 Fax (08) 379-4634

Canada Tel (403) 264-5610

Canadian Society of Pe t ro leum Geologists #505,206 7th Avenue S.W. Calgary, Alber ta T2P 0 W 7


Foreword Utilization of Hydrocarbon Seep Information

Geochemical prospecting for petro leum is the search for chemically identifiable surface or near-surface occurrences of hydrocarbons as clues to the location of o i l or gas accumulations. I t extends t h r o u g h a range from observation of clearly visible o i l and gas seepages at one extreme to the identi f icat ion of m i n u t e traces of hydrocarbons determinable on ly b y h i g h l y sophisticated analytical methods at the other. There is no question i n pr inciple about the value of the m e t h o d for petro leum explorat ion i f proper ly appl ied. Historically, most of the w o r l d ' s major petroleum-bearing areas and m a n y of its largest o i l and gas fields were first called to attention because of visible o i l a n d gas seepages. The mere presence of higher hydrocarbons i n a region is encouraging i n that i t usual ly proves that conditions i n that region have been suitable for at least some petroleum generation. Of ten seepages are i n close p r o x i m i t y to commercial o i l and gas pools, b u t the absence of seepage does not at a l l negate prospects because i t m a y only indicate that there has been litt le escape f r o m such pools due to good sealing rocks.

O i l and gas are mobi le f lu ids and rocks are generally permeable. Surface o i l and gas seeps p r i m a r i l y reflect avenues of m i g r a t i o n (or escape) f r o m deeper a n d sometimes laterally distant locations. Moreover, because avenues of m i g r a t i o n (or escape) f r o m deeper accumulations vary considerably i n the degree to w h i c h they are sealed, the quantitat ive size of a seep has l i tt le relationship to the size of the accumulat ion. Some small accumulations are m a r k e d b y strong visible seepages, whereas some of the largest accumulations are so w e l l sealed that they show no visible seepages and o n l y microscopic seepages or none at al l . The value of seepages, visible or microscopic, is thus largely a matter of the accuracy w i t h w h i c h they can be interpreted geologically. I n some case (e.g., Burgan f ield) a w e l l d r i l l e d vertically at the site of seepage w o u l d have discovered the f ie ld . I n other cases where escape of hydrocarbons has been along l o w d i p p i n g faul t planes or l o w d i p p i n g carrier beds, surface seepages m a y be m a n y miles laterally f r o m vertical superposit ion over the o i l or gas accumulation. A g a i n , the value of the i n f o r m a t i o n o n the seepage, visible or microscopic, is a lways there, b u t i t is on ly the geologic interpretat ion that al lows cashing i n o n its value.

O n l a n d , most visible seepages have already been recorded and the nature of the relat ionship to subsurface pe t ro leum accumulations has been at least s tudied i f not always successfully determined. The m a i n task n o w for geochemical prospecting is the identi f icat ion of the invisible or less clearly manifested "seepages" that can be determined o n l y b y detailed chemical analysis of f lu ids i n surface a n d near-surface rocks. The problems are not whether there is any value to the data b u t rather are (1) the techniques for identif icat ion, (2) the geologic interpretation, and (3) the qual i ty of the interpretation g o o d enough to just i fy the cost.

Offshore, the s i tuation is s l ight ly different. Visual observation of offshore seepages has been i m p e d e d b y the water cover, a n d reliance must be placed m a i n l y o n chemical analysis of the water c o l u m n a n d the interstit ial waters f i l l i n g the pores of the blanket of y o u n g sediment covering the sea floor. A g a i n , there seems to m e no question of the innate value of the geochemical i n f o r m a t i o n , posit ive or negative. A n d again, the problems are w i t h the techniques of identif icat ion and geologic interpretation, and whether the interpretat ion is good enough to just i fy costs. There is n o t h i n g w r o n g w i t h the concept; i t is on ly a question of our abi l i ty to collect the data adequately a n d to interpret the results correctly, at a reasonable cost.

A geochemical survey should be t h o u g h t of not as a black magic means of spott ing the location of o i l and gas pools b u t on ly as a s imple c o m m o n sense m e t h o d of gathering data o n hydrocarbon occurrences too di lute to make visible seeps or impregnat ions—data w h i c h i f collected reliably, interpreted wisely, a n d used intel l igently a long w i t h al l other lines of evi dence w i l l a lways be h e l p f u l i n petro leum explorat ion of any area.

Hollis D. Hedberg March 1981

Hi


AAPG

Wishes to thank the following for their generous contributions

to Hydrocarbon Migration

and Its Near-Surface Expression

Association of Petroleum Geochemical Explorationists •

Conoco Inc. •

Dietmar Schumacher •

Exploration Technologies, Inc. •

Exxon Ventures (CIS), Inc. •

Geo-Microbial Technologies, Inc. •

Geoscience & Technology, Inc. •

Petrobras •

Phillips Petroleum Company •

Shell Offshore, Inc. •

The University of Saskatchewan •

Zonge Engineering and Research Organization, Inc. •

Contributions are applied against the production costs of publication, thus directly reducing the book's purchase

price and making the volume available to a greater audience.

w


Contents F o r e w o r d i i i Ut i l i za t ion of H y d r o c a r b o n Seep I n f o r m a t i o n —Mollis D. Hedberg

A b o u t the Edi tors v i i i Preface ix

Characteristics of H y d r o c a r b o n Seepage

Chapter 1 1 Dis t r ibut ion of Subsurface H y d r o c a r b o n Seepage i n Near-Surface M a r i n e Sediments

—Michael A. Abrams

Chapter 2 15 Detecting H u i d M i g r a t i o n i n Shallow Sediments: Continental Slope Environment ,

G u l f of Mexico —Michael J. Kaluza and Earl H. Doyle

Chapter 3 27 Remote Sensing Inventory of Act ive O i l Seeps and Chemosynthetic Communi t i es

i n the N o r t h e r n G u l f of Mexico —Ian R. MacDonald, J. F. Reilly, jr., S. E. Best, R. Venkataramaiah, R. Sassen,

N. L. Guinasso, Jr., and J. Amos

Chapter 4 39 Geologic Controls on the Dis t r ibut ion of Chemosynthetic Communi t i es i n the G u l f of Mexico

—James F. Reilly, Jr., Ian R. MacDonald, E. K. Biegert, and James M. Brooks

Chapter 5 63 Geochemistry of H y d r o c a r b o n Seepages i n Azerbai jan

—I. S. Guliev and A. A. Feizullayev

H y d r o c a r b o n - I n d u c e d A l t e r a t i o n

Chapter 6 71 Hydrocarbon- Induced Al te ra t ion of Soils a n d Sediments

—Dietmar Schumacher

Chapter 7 91 Test of Hydrocarbon- Induced Magnetic Patterns i n Soils: The Sanitary L a n d f i l l as Laboratory

—Brooks B. Ellwood and Burke Burkart

Chapter 8 99 Magnetic Contrasts as a Result of H y d r o c a r b o n Seepage and M i g r a t i o n

—Hans G. Machel

Chapter 9 I l l Relationship of Near-Surface Magnetic Anomal ies to O i l - and Gas-Producing Areas

—Robert S. Foote

Chapter 10 127 Induced Polarization Effects Associated w i t h H y d r o c a r b o n Accumulat ions : M i n i m i z a t i o n

and Evaluat ion of C u l t u r a l Influences —Norman R. Carlson and Kenneth L. Zonge

v


vi Contents

H y d r o c a r b o n M i g r a t i o n M e c h a n i s m s a n d Seepage M o d e l s

Chapter 11 139 H y d r o c a r b o n M i g r a t i o n — A V i e w f r o m the Top

—Martin D. Matthews

Chapter 12 157 Compar ison of L i g h t H y d r o c a r b o n Microseepage Mechanisms

—Ronald W. Klusman and Mahyoub A. Saaed

Chapter 13 169 Compar ison of Seepage and Seal Leakage Rates

—Chris J. Clayton and Paul R. Dando

Chapter 14 173 Molecular Di f fus ion of L i g h t Hydrocarbons i n Sedimentary Rocks and Its Role

i n M i g r a t i o n and Dissipation of N a t u r a l Gas —B. M. Krooss and D. Leythaeuser

Chapter 15 185 Ascending F l u i d Plumes A b o v e Devonian Pinnacle Reefs: N u m e r i c a l M o d e l i n g and Field

Example f r o m West-Central Alberta , Canada —B. J. Rostron and J. Toth

Chapter 16 203 H y d r o c a r b o n H u x Variations i n N a t u r a l and Anthropogenic Seeps

—Victor T. Jones III and Stephen G. Burtell

I n t e r p r e t i v e M e t h o d s a n d A n a l y t i c a l Techniques

Chapter 17 223 Unders tanding Geology as the Key to U s i n g Seepage i n Explorat ion: The Spectrum

of Seepage Styles —Jane Thrasher, Andrew J. Fleet, Stephen J. Hay, Martin Hovland, and Stephan Duppenbecker

Chapter 18 243 Importance of Sampling Design and Density i n Target Recognition

—Martin D. Matthews

Chapter 19 255 H o w of Format ion Waters: L i k e l y Cause for Poor D e f i n i t i o n of Soil Gas Anomal ies

over O i l Fields i n East-Central Alberta , Canada —Stephan Holysh and Jozsef Toth

Chapter 20 279 Thoughts of a Hydrogeologis t o n Vertical M i g r a t i o n a n d Near-Surface Geochemical

Explorat ion for Petroleum —Jozsef Toth

Chapter 21 285 Research-Derived Insights i n t o Surface Geochemical H y d r o c a r b o n Explorat ion

—Leigh C. Price

Chapter 22 309 Interpretat ion of Methane Carbon Isotopes Extracted f r o m Surficial M a r i n e Sediments

for Detection of Subsurface Hydrocarbons —Michael A. Abrams


Contents vii

Chapter 23 319 A M e t h o d for Processing A d s o r b e d Methane Stable Isotope Data f r o m the Near-Surface

Based o n Fractionation —Dirk Kettel

Chapter 24 337 Postulated Generation of Bacterial Methane f r o m Seepage Petroleum i n Sea Floor Sediments

of the G u l f of Mexico —K. F. M. Thompson

Chapter 25 341 Potential 13C/12C Variations i n Bacterial Methane i n Assessing O r i g i n

of Environmenta l Methane —A. M. Zyakun

Chapter 26 353 Long-Term and Seasonal Trends i n Responses of H y d r o c a r b o n - U t i l i z i n g Microbes

to L i g h t Hydrocarbons i n Shallow Soils —James Tucker and Daniel Hitzman

Chapter 27 359 Contaminat ion of Shallow Cores: A C o m m o n Problem

—Tony Barwise, Steve Hay, and Jane Thrasher

Chapter 28 363 Predicting O i l Properties f r o m Core Huorescence

—Tony Barwise and Steve Hay

E x p l o r a t i o n Case H i s t o r i e s

Chapter 29 373 Surface Geochemistry as an Explorat ion Tool i n the South Caribbean

—Jane Thrasher, David Strait, and Ricardo Alvarez Lugo

Chapter 30 385 Near-Surface C o r i n g i n the Beaufort a n d C h u k c h i Seas, N o r t h e r n Alaska

—N. Piggott and M. A. Abrams

Chapter 31 401 H y d r o c a r b o n Prospecting i n the A m a z o n Rain Forest: A p p l i c a t i o n of Surface Geochemical,

Microbiological , a n d Remote Sensing Methods —M. R. Mello, F. T. Gonqalves, N. A. Babinski, and F. P. Miranda

Chapter 32 413 Petroleum Geology a n d Geochemistry of Miocene Source Rocks and H e a v y Petroleum

Samples f r o m Huasna Basin, Cal i fornia —Alan S. Kornacki

Chapter 33 431 Significance of Geochemical Anomal ies i n H y d r o c a r b o n Explorat ion:

One Company 's Experience

—Robert W. Potter II, Paul A. Harrington, Alan H. Silliman, and James H. Viellenave

I n d e x 441


About the Editors

D i e t m a r ( "Deet " ) Schumacher is c u r r e n t l y a Research Professor w i t h the Earth Sciences a n d Resources Institute (ESRI) of the Universi ty of U t a h in Salt I.ake City. H e received his B.5. and M.S. degrees in geology f r o m the Universi ty of Wisconsin and his Ph.D. f r o m the Universi ty of Missour i . Deel taught geology at the Universi ty of Arizona for 7 years before jo ining Phill ips Petroleum as a research geologist i n 1977. H e he ld a var ie ty of posi t ions at Phi l l ips , i n c l u d i n g Research Supervisor for petroleum geology and Senior Geological Specialist. Deet then joined Pennzoil in 1982 a n d served as manager of g e o l o g y / g e o c h e m i s t r y before t ransferr ing to assignments w i t h Pennzoil In ternat ional , Pennzoi l Offshore , a n d Pennzoil 's Technology G r o u p . In 1994, Deet accepted a posit ion as Research Professor at F.SRI. H e is presently an Associate Editor of the A A P G Bulletin and a past president of both the Houston Geological Society and the Association of Petroleum Geochemical Explorationists. Deet has had a long-standing interest in exploration and development applications of p e t m l e u m geochemistry, part icularly surface exploration methixis . It is this interest that resulted in his convening ( w i t h Michael Abrams) the A A P G H e d b e r g Research Conference "Near-Surface Expression of Hydrocarbon M i g r a t i o n " and the edi t ing of this vo lume.

M i c h a e l A b r a m s is presently a Senior Exploration Geochemist w i t h Exxon Ventures (CIS), Inc. Michael has had assignments i n e x p l o r a t i o n , p r o d u c t i o n , a n d research all over the w o r l d d u r i n g his 15 years w i t h the Exxon Corporat ion. He was introduced to surface geochemistry as a marine geologist early i n his career as an explorationist. His first assignment w i t h Exxon was to design a research program to investigate acoustic anomalies i n offshore Alaska w h i c h were thought to be due to leakage of subsurface hydrocarbons. Michael has since championed surface geochemistry as a viable explorat ion tool in frontier basins, both w i t h i n Exxon and t h r o u g h his publ ica t ions . M i c h a e l at tended the Univers i ty of Rochester, George Washington University, and the Universi ty of Southern California.

viii


Preface

Over the past 60 years, numerous direct and indirect hydrocarbon explorat ion methods have been developed. The applicat ion of these surface prospecting methods to o i l and gas explorat ion has resulted i n var ied success and considerable controversy. Few question that hydrocarbons migrate to the near surface i n amounts that are detectable, b u t m a n y are skeptical of h o w such i n f o r m a t i o n can be integrated into more conventional explorat ion a n d development programs. O u r understanding of the process of hydrocarbon m i g r a t i o n f r o m source or reservoir to the near surface is p o o r l y understood and severely l imi ts the interpretat ion of surface geochemical data. The past decade has seen a renewed interest i n this topic w h i c h , w h e n coupled w i t h developments i n analytical and interpretive methods, has produced a n e w b o d y of data and insights i n this area.

This publ icat ion is a direct o u t g r o w t h of the A A P G Hedberg Research Conference held i n A p r i l 1994 entit led "Near-Surface Expression of H y d r o c a r b o n M i g r a t i o n . " The purpose of this research conference was to gather international experts f r o m i n d u s t r y a n d academia to critically examine the process of hydrocarbon m i g r a t i o n and its var ied near-surface expressions. The w i d e range of topics discussed is reflected b y the papers selected for inc lusion i n this v o l u m e : near-surface m a n ifestations of hydrocabon m i g r a t i o n , hydrocarbon- induced alteration of soils and sediments, m i g r a t i o n mechanisms, hydrocarbon f l u x measurements, sampl ing and analytical techniques, survey design and interpretation, physical and geological implicat ions of hydrocarbon leakage, and finally, explorat ion case studies.

Conference participants engaged i n l ive ly discussion, and despite a lack of consensus o n a n u m b e r of topics, there was general agreement o n the f o l l o w i n g conclusions:

/ H y d r o c a r b o n accumulat ions are d y n a m i c ; seals are imperfect . / A l l p e t r o l e u m basins have some t y p e of near-surface h y d r o c a r b o n leakage. y Surface expression of leakage is not a lways detectable b y convent ional means. / H y d r o c a r b o n seepage can be active or passive, a n d i t can be visible (macroseepage)

or o n l y chemical ly detectable (microseepage). / Seepage expression, whether active or passive, is a f u n c t i o n of m a n y factors other

than the mere presence or absence of active h y d r o c a r b o n generation a n d m i g r a t i o n . </ M i g r a t i o n occurs m a i n l y vertically, b u t i t can also occur over l o n g distances laterally. / Hydrocarbons can m o v e vert ical ly t h r o u g h thousands of meters of strata w i t h o u t

observable faults or fractures i n a relat ively short t ime (weeks to years). / Relationships between surface geochemical anomalies a n d subsurface accumulat ion

can be complex; p r o p e r interpretat ion requires in tegrat ion of seepage data w i t h geological , geophysical , a n d h y d r o l o g i c a l data.

/ H y d r o c a r b o n m i g r a t i o n mechanisms are s t i l l p o o r l y unders tood . Present evidence favors effusion as the process of macroseepage a n d b o u y a n c y of microbubbles as the mechanism for microseepage.

I t is our hope that the i n f o r m a t i o n and ideas presented i n this v o l u m e w i l l assist the f o r m u l a t i o n of more effective explorat ion and development strategies b y p r o v i d i n g a better understandi n g of hydrocarbon m i g r a t i o n and its near-surface effects. O n l y t h r o u g h a ful ler unders tanding of these processes can surface explorat ion technology achieve its f u l l potential , a goal increasingly i m p o r t a n t as our indus t ry strives to i m p r o v e explorat ion efficiency d u r i n g these times of economic uncertainty.

Dietmar Schumacher

Michael Abrams

ix


Acknowledgments

We sincerely appreciate the assistance g iven b y the f o l l o w i n g i n d i v i d u a l s w h o generously p r o v i d e d critical reviews of the manuscripts publ i shed i n this v o l u m e :

J im A l l a n * ( Imper ia l O i l Resources) Peter Blanchette (Surface Exploration) N o r m a n Carlson (Zonge Engineering) T i m o t h y Collett (USGS) James Corthay (Exxon Explorat ion Co.) Steve Creaney (Exxon Explorat ion Co.) Wal ly D o w (DGSI) D o u g Elmore (Univers i ty of Oklahoma) John Geissman (Universi ty of N e w Mexico) Joel Gevirtz (Interscience) H . Robert H o p k i n s (Geosat Committee) Jeff H u l e n (ESRI, Univers i ty of Utah) A l a n James (Exxon Product ion Research) D i r k Kettel (Consultant) Ron K l u s m a n (Colorado School of Mines) A l a n Kornack i (Shell Offshore)

Steve M a y (Exxon Product ion Research) M a r t y Gorbaty (Exxon Corporate Research) Paul Ph i lp (Universi ty of Oklahoma) N e i l Piggott (British Petroleum) Bi l l Powel l (Exxon Product ion Research) Le igh Price (USGS) M e l o d y e Rooney ( M o b i l Research) Roger Sassen (GERG, Texas A & M ) D o n a l d Saunders (Recon Exploration) Len Srnka (Exxon Product ion Research) L o r i Summa (Exxon Product ion Research) K e n Sundberg (Phill ips Petroleum) Jane Thrasher (British Petroleum) A l l a n T r i p p (Univers i ty of Utah) W. A . Young (Exxon Product ion Research).

The conscientious and painstaking reviews of the manuscripts b y these colleagues have greatly i m p r o v e d the scientific content a n d value of this v o l u m e .

We also w i s h to thank the editorial a n d p r o d u c t i o n staff of A A P G , part icular ly A n n e Thomas a n d K a t h y Walker.

Dietmar Schumacher

Michael Abrams

*Jim Allan died i n June 1996 after a difficult battle w i t h cancer. Jim's contribution to this publication, as well as his contributions to the science of geochemistry, w i l l always be remembered and appreciated.

X


hydrocarbon migration and its near-surface

Documents