Well Architecture vs. Reservoir Architecture: Key Aspectsand potential applications in Venezuelan Reservoirs

(1)

Source: (1) Robison, SPE 38497, 1997

By: Ana María Hernandez

If we imagine an area with all possiblefacies architectures ...

Reservoir Architecture...is the three-dimensional morphology of the reservoirs as defined by its geometry, dimensions, orientations and lateral and vertical heterogeneities (1)

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Basic Concept

Source:modified from Terrigenous Clastic Depositional Systems,chapter 16,fig.16.6,p. 434,Galloway,W;Hobday,D (1996).

Common reservoir architectures: Common reservoir architectures: What is the best well configuration?What is the best well configuration?

MultilateralMultilateral Fishbone/StackedFishbone/Stacked

Dual lateralDual lateral MultibranchMultibranch

Knowledge of the geometries, dimensions and orientations of the reservoirs is a key aspect to design wells with complex architecture

Source (1a,1 b,1c,1d): modified from Terrigenous Clastic Depositional Systems,chapter 15,fig.16.6,p. 401,404,408,Galloway,W;Hobday,D (1996).

Scale: 10Scale: 10-1-1 to 10 to 1022 Km Km22

LOW MODERATE HIGH

LOW

Wave-dominated Delta

Tidal depositsMeander Belt

Fluvial Dominated

MODERATEEolian

Distal Delta Front

Braided Stream, Tide Dominated

HIGHTurbidites Braid Delta

Fluvial Dominated Delta

Lateral Heterogeneity

Vert

ical H

ete

rog

en

eit

y

Compartmentalized

Unconnected

Laterally bypassed

Low recovery efficiency,

Design infill drilling

and recompletions

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In general, Venezuelan Reservoirs present high lateral and vertical heterogeneities, so we should search the best technological options

to optimize our recovery strategiesSource: modified from (1) The Three-dimensional facies architecture of terrigenous clastic sediments and its implication for hydrocarbon

discovery and recovery. Concepts in Sedimentology and Paleontology. Miall,A;Tyler,N. Chapter 1, p.4 t. 1-2 (1991)

Reservoir Heterogeneities

It is common to observe:

- Complex Channel Geometry

and Bedding Character

- Abrupt changes in Lateral/ Vertical

relationship of facies

Also...- Channel Patterns are frequently modified by tectonism

At Reservoir Scale....

Source (1): modified from Terrigenous Clastic Depositional Systems,chapter 4,fig.4.13,p.79,Galloway,W;Hobday,D (1996).(2)The Geology of Fluvial Deposits, Miall(1996) Chapter 11,p.349,fig. 11.8

Knowledge of the Petroleum Production System and Reservoir Compartmentalization will help to design the

bestReservoir Recovery Strategies

Petroleum Production System Reservoir Compartmentalization

Key Aspects

Source: modified from Petroleum Production System,Chapter 1,p.11,fig.1-6, Economides,M;Hill,D;Ehlig-Economides,C (1993). (2) The Three-dimensional facies architecture of terrigenous clastic sediments and its implication for hydrocarbon discovery and recovery. Concepts in Sedimentology and Paleontology. Miall,A;Tyler,N. Chapter 1, p.5 fig.6-b (1991)

Fracturas axialesFracturas axialesFracturas transversalesFracturas transversales

EsfuerzoEsfuerzoverticalvertical

Esfuerzos horizontales minimosEsfuerzos horizontales minimos

Esfuerzos horizontales máximosEsfuerzos horizontales máximos

KICK-OFF POINT

60°/100 ft

20°/100 ft

10°/100 ft

Horizontal Well at Midpoint

74 ft362 ft846 ft

20 ft

40 ft

Geomechanics

The match between geological and geomecanical data is important to get the best well orientation

Geological data contribute also in the selection of the:- Junction type- Well trajectory- Drainage points- Kick-off point- Radius type- Longitude of laterals- Orientation of laterals- Well type- Completion System

Important issues in the design of complex architecture wells

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Source: (1) Longbottom, SPE 36994 (1996)

Increasing Degree of Geologic Assurance

I ncreasi n

g E

con

om

ic Feasi b

il it y

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Automation Advanced Drilling

Environmental

Platforms

ArcticSubsea

Floating Systems

Gas Processing

Conv. drilling

Liquidprocessing

Sand Control

Acid.

Fracturing

Perf.Chem. Treat.

Subsurface equip.

Low Med High

Low

Med

Hig

hTechnology proficiencyTechnology proficiency

Tech

nolo

gy p

ote

nti

al

Tech

nolo

gy p

ote

nti

al

(2)

Identified Demostrated UndiscoveredMeasured Indicated Inferred

EconomicPrimary Oil field

New Field primary/secondary

Sub-Economic

Old Field Tertiary

New Field Tertiary

Secondary Oil FieldReserves

Resources

Economical and Technological aspects

Source: (1) Federal Energy Administration, National Energy Outlook,1976; (2) Oligney,R; Economides,M; Technology as an asset, Hart´petroleum Engineer International,1998

International experiences with MTL technology

Prudhoe Bay UnitAlaska, USA(3)

East Wilminton FieldCA, USA(2)

Weyburn UnitSaskatchewan

Canadá(6)

Statfjord, Alison, Beryl,Tern, Troll, Forties,Gullfaks, Pickerill, K14-FB and Harding Fields; North Sea (10-17)

Burbank FieldOK,USA(5)

South Furious Field Malaysia (8)

Funiwa FieldNigeria(4)

Bongkot FieldThailand(9)

Siedenburg Field ,Germany(7)

Sandstone ReservoirsCarbonate ReservoirsGranite

Bachaquero,Cabimas,Morichal and Bare Fields

Venezuela(1)

Source: (1) Tirado et al,Perforacion no convencional,1998;(2) Brister, SPE 38268,1997;(3) Aubert,IADC/SPE 39388,1998; (4) Aloko et al,SPE 48843,1998;(5) Ellis,SPE 37493;(6) Hart´s Petroleum Engineer International,1997; (8)Wong et al, SPE 38030,1997; (9) Goffart, Petrol Tech n°416,p 49-53,1998;(10) Andreassen et al,IADC/SPE 39329,1998;(11) Hands et al,SPE 50394,1998;(12) Roberts et al,SPE 50663,1998;(13)Njaerheim et al,IADC/SPE 39356;(14)Freeman et al,IADC/SPE 39369,1998; (15) McLellan et al,SPE 50676, 1998;(16) Bokhari et al,SPE 38629,1997; (17) Jones et al,OTC 8534,1997

Field: South Furious, Sabah MalaysiaReservoir Type: sand-shale oil sequences/faultedOperator: ShellWell Type: MultilateralDeep: 3500 ft

Objective: “to connect reservoir compartments and to increase the drainage area in an infill project ”

(Wong,Boon, Chia, Chong, SPE 38030, 1997)

International MTL experiences in sandstone reservoirs

x

z

3D VIEW Y

Field: K 14-FB 102Reservoir Type: Gas Bearing Rotliegend SandstoneOperator: ShellWell Type: Dual LateralDeep: 2500 ft

International MTL experiences in sandstone reservoirs

Objective: “ to optimize production capacity and Objective: “ to optimize production capacity and reservoir drainage for a tight formation”reservoir drainage for a tight formation”

(Hands,Francis,Whittle,Rajasingam, SPE 50394, 1998)(Hands,Francis,Whittle,Rajasingam, SPE 50394, 1998)

International MTL experiences in sandstone reservoirs

Field: Tern , northern North SeaReservoir Type: Deltaic oil sand, Middle Jurassic Brent GroupOperator: ShellWell Type: MultilateralDeep: 9000 ft

Objective: “to enhance profitability of the field by the Objective: “to enhance profitability of the field by the exploitation of poorer quality formations ”exploitation of poorer quality formations ”

(Roberts, Kirkwood, SPE 50663, 1998)(Roberts, Kirkwood, SPE 50663, 1998)

Fuente: (1) Campo Cabimas alternativa de desarrollo mediante módulos multipozos , EPC-7235, R. Faria ; L. Rondón . Caracas, Mayo 1983,(2) Perforación direccional de pozos desde una localización común, IT-9267, Salazar J. Arturo G. Villasmil H. Lagunillas , Feb. 1983(3) Factibilidad de utilización de taladros inclinados para perforación desde módulos multipozos ,Informe del grupo de trabajo. Casona J., Finol A., Mariño E., Farias , López R.Septiembre 1982, (4) Boletín RIPPET, Vol.. 1, N° 1 Marzo 1983.; (5) Perforación de pozos multilaterales,. Experiencias de aplicación en Vzla . INT-5934, 1999. (6)Perforación no convencional, SIT-00059,96 (6) Espinosa M., Conoco /maraven ´s Financing effort on petrozuata sets String of benchmarks ,Oíl & Gas Journal , 96:8,2/23/99 (7)Borjas K.; et al INT-3804,97 (8) Larez N.IT-9458, Nov.. 1983.

Evolution of the MTL drilling in Venezuela

1981-82 1983.... 1995 1996 1997 1998 1999

* Maraven drilled 4scattered directional wells in Lagunillas Field (1)

*Maraven designed a conceptual development of Cabimas Field under multiple surface arrangement

* Maraven, Cabimas Field, well R-823 with 4 laterals. Sanding problems (5-6)

* Bachaquero Field,w ell BA-2186; three laterls and a production of 640 BPND. Sanding problems, w ell is shut off (5)

* Motatan Field,well location AD-22-2 is planned as a multilateral (7)

* Petrozuata (financial parnership between PDVSA and CONOCO) is drilling MTL wells in Heavy oil reservoirs of the O.B. (6)

* Phillips/ PDVSA is drilling a deep MTL well in Maracaibo

* Multiple well drilling is adapted from deviated or conventional directional drilling (4)

(1680 MMb of remanent

reserves) (1-3)

* Bare Field,OB, well MBF-445; main hole and a 1500 ft. Long lateral (5)

* A dual lateral well drilled in Morichal , well MPG-59. Well is shut off.

* Several exploitation units are planning to include MTL well in their exploitation plans

* Directional drilling: methodology and logistic (8)

*Mara field, well DM-152, open hole (850 BPND)

MaraDM-152

BachaqueroBA-2186

Cabimas R-823

MorichalMPG-59Bare

Junction and Lateral CollapseSand Production /Cementation

Water Production

Sand Production at the junction

Drilling and Completion problems

Junction andLateral CollapseSand Production

Main Problem: The Junction

Previous MTL wells in PDVSA,VenezuelaWhy MTL technology has had relative success?

Identification of reservoir types and their production problems in each

Exploitation Unit (E.U.). Where could MLT be applied in Venezuela?

Multidisciplinary Technology TeamFirst Step: Candidate Recognition

Maracaibo Basin (12 E.U.)Maracaibo Basin (12 E.U.)

Eastern Basin (12 E.U.)Eastern Basin (12 E.U.)

Apure-Barinas Basin (2 E.U.)Apure-Barinas Basin (2 E.U.)Orinoco Belt (4 E.Orinoco Belt (4 E.U.)U.)

Screening Criteria:

-Shallow Reservoirs (< 10000 Ft)

-Reservoirs with Horizontal wells

-Reservoirs with specific production

problems where MTL are recommended

-E.U. with integrated studies

Venezuelan Exploitation UnitsVenezuelan Exploitation Units

WESTERN EXPLOITATION UNITS SOUTH E. U. ORINOCO BELT E.U.Distrito Lagunillas Distrito Maracaibo Distrito Tia J uana Apure Cerro NegroBarua Motatan Tierra Oeste Tia J uana Lago Barinas Zuata

Bachaquero Lago La Salina Tierra Este HamacaLagocinco Lagomar Lagunillas Lago MacheteLagotreco Lagomedio

Centro Sur Lago EASTERN EXPLOITATION UNITS

Distrito Maturin Distrito Punta de Mata Distrito Anaco Distrito San Tome Distrito MorichalEl Furrial Carito/Amana Gas/Condensate Light-Medium MediumNorth Pirital Light/Medium Heavy Heavy-X heavy

Extra-heavy Bitumen

Exploitation Units Pre-Selected to apply MTL Technology

WESTERN EXPLOITATION UNITS SOUTH E. U. ORINOCO BELT E.U.

Distrito Lagunillas Distrito Maracaibo Distrito Tia J uana Apure Cerro NegroBarua Motatan TIERRA OESTE Tia J uana Lago Barinas ZUATA

BACHAQUERO LAGO La Salina TIERRA ESTE HamacaLagocinco Lagomar Lagunillas Lago Machete

Lagotreco Lagomedio

Centro Sur Lago

EASTERN EXPLOITATION UNITSDistrito Maturin Distrito Punta de Mata Distrito Anaco Distrito San Tome Distrito Morichal

El Furrial Carito/Amana Gas/Condensate Light-Medium Medium

North Pirital Light/Medium Heavy HEAVY/X-HEAVYX-HEAVY Bitumen

Mara

Barúa-Motatán

Eoceno Frac Bachaquero - 02

Tía Juana ( tierra/lago) Orocual

Sta Bárbara

Melones

Bare

Carito Norte

Acema 200

Chimire

Morichal

Santa Rosa

LagomarPirital

BorburataCampos tradicionales

Barinas

In ProgressIn Progress

Proposals 2000+Proposals 2000+

Pre- selectedPre- selected

Cabimas

Reservoir candidates to apply MTL technology (2000-2006: +/- 20 reservoirs)

Geographic LocationGeographic Location

ANACO/SAN TOME AREAANACO/SAN TOME AREAIncrease Recovery FactorIncrease Recovery Factor

in Gas-Condensate/compartmentalized Reservoirsin Gas-Condensate/compartmentalized Reservoirs

TRADITIONAL FIELDS (BARINAS)TRADITIONAL FIELDS (BARINAS)Water ConingWater Coning

Carbonate reservoirsCarbonate reservoirs

ORINOCO BELTORINOCO BELTHeavy Oil: New Exploitation PlansHeavy Oil: New Exploitation Plans

for enhanced crudesfor enhanced crudes

Future Plans: MTL Technology Opportunities in PDVSA, VenezuelaWhat are the challenges?

MAIN ISSUES:

- Junction Type

-Well Architecture vs. Reservoir Architecture

-Completion System

-To design New Exploitation Plans

MARACAIBO FIELDSMARACAIBO FIELDSPressure Decline,Pressure Decline,compartments,compartments,

selective Productionselective Production

AMZW

AKAQ

Motatan Field, Maracaibo

Dome South NorthOOIP: 1458 690 MMBLs

Reserves: 367 93 MMBLs

R. Press: 3400 3200 (LPC)

Deep: 8900 8320 Feet

Porosity: 12 11 (%)

Permeability: 40 25 mD

API° Gravity: 19 21

Objective: To produce unconnected zones due toObjective: To produce unconnected zones due toStructural/Stratified Reservoirs where MTL wellsStructural/Stratified Reservoirs where MTL wells

are recommendedare recommended

( Felix Díaz)( Felix Díaz)

LENS-1

LENS-2

LENS-3

LENS-4

BA-127 BA-59

BA-231

BA-227

Area: 25555 acresNet Thickness: 235 feetPorosity: 29 %Permeability: 1500 mDAPI° Gravity: 15OOIP: 9000 MMBLsProductionOil: 1608 MMBLsGas: 968202 MMPCsOil Reserves (12/98) 2678 MMBLS

Objective: To Substitute twin wells for stacked wells/SAGD configuration for steam injection

Bachaquero -02 Field, Maracaibo

(Juan Herrera)(Juan Herrera)

Melones Field, Eastern VenezuelaMelones Field, Eastern Venezuela

OOIP: 826,1 MMBLs

Reserves: 90,8 MMBLs

R. Pressure: 1290 (lpc)

Deep: 3500 feet

Por. : 28 %

K: 700 mD

API° Gravity: 10-12

Recovery factor: 11 %

Objective: To increase recovery factor in

compartmentalized fluvial-deltaic reservoir where

Dual lateral wells are suggested

(Magalys Araujo)(Magalys Araujo)