PC Based Reservoir Analysis System Allows Quick Decision on E&P Well

Plans for Black Widow Prospect

J.L. Buchwalter Gemini Solutions, Inc.

T.M. Campbell

Mariner Energy, Inc.

AKNOWLEDGEMENT

PGS/Diamond Geophysical Service Corporation

OUTLINE

• INTRODUCTION

• CASE STUDY- Exploration Well Sidetrack

•DRILLING RESULTS

•PRODUCTION

• CONCLUSIONS

When Can Reservoir Simulation Be Applied to Maximize Value ?

Prevailing Idea in Petroleum Industry • Once you understand the reservoir in detail

GIGO• Calculate accurate reserves and production profiles

Problem:Often too late to optimize drilling and development decisions

The Hidden Truth • Study before you understand the reservoir in detail• Impact exploration drilling and development

maximize the economics

Key Facts

Central GOM– EW 966– Water Depth of 1853

ft

Participants– Mariner Energy 69%

(Operator)– Devon Energy 31%

Ultimate Reserves– 11 MMBOE

History– Discovered Apr 1998– Sanctioned Jan 2000– Production Oct 2000– Peak Rate Oct 2001

• 11,000 Bpd• 9 MMcfpd

FIELD SUMMARYSmall oil discovery in 1998

•Ewing Bank area of the OCS Central Gulf region.

•Located approximately 3 miles east of Morpeth.

Developed via a single well subsea tie-back to the Morpeth TLP in EW 921.

First oil occurred in October 2000.

LOCATION MAPS

Index Map

Keathley Canyon

Henry HubVermilion

Erath

EastCameron

Vermilion

SouthMarshIslandNorth

Addition

Vermilion Bay

MarshIsland

KeathleyCanyon

GardenBanks

AUGER Serrano

Llano

MACARONI

COOPER

BALDPATE

SouthMarshIslandSouth

AdditionVermilionSouth

Addition

CONGER

SouthMarshSouth

Eugene IslandSouth Addition

EugeneIsland

Calumet

JOLLIET

MARQUETTE

Ship ShoalSouth Addition

BULLWINKLE

TYPHOON

HoumaNorth

Terrebonne

GibsonGardenCity

Fuji

Green Canyon

Walker Ridge

ShipShoal

SouthPelto

SS28

CaillouIsland

SouthTimbalier

TimbalierBay

POPEYE

SUNDAYSILENCE

ANGUS

South TimbalierSouth Addition

GC 29

GliderGENESIS

BRUTUS

Louisiana

Larose

K2/Timon

Atlantis

KING KONG

ALLEGHENY

HOLSTEIN

Mad Dog

McKinley

ROCKY

TROIKA

Atwater Valley

ALABASTER/ZINC

GrandIsle

WestDelta

Clovelly

Fourchon

ARNOLD

MC 441

MANTA RAY

BLACK WIDOW

MORPETHEW

S.Pass

WestDeltaSouth

BretonSound

Venice

NorcoSt.James

NewOrleans

0 4020

Km

Neptune

LUNDLund

EUROPA

MARS

DIAMOND

PLUTO

URSA

MississippiCanyon

Field Map

16"

Dis

cove

ry g

as p

ipel

ine

4" Manta Ray-

Lobster-EW873

oil pipeline

3" oil

3"gas

gas

oil

10"oil

oil/gas

2 x 6" Arnold-Lobster

oil/cond. pipelines

8" D

isco

very

gas

pip

elin

e12

" M

orpe

th-G

I 115

Aoi

l pip

elin

e

Discovery30" gas pipeline

GC 82

SEATTLE SLEW

PRINCE

EW 826

(ceased)

GC 31(ceased)

MANTA RAY

LOBSTER

OYSTER

ARNOLD

MORPETH

BLACKWIDOW

EW 878

Grand IsleSouth Addition

South TimbalierSouth Addition

Ewing Bank

12ST1

21

1,2

3

4

1ST21ST1

1

3ST1

1ST12 2ST1

3,44ST1

A1ST1,2

A2

2, 2ST11

1

1

1

2

1

1

1

1

3

1

1

1A3

A1

A4

1

2

1

1,2

3,4

1

1

1

1ST1

1,2

1

1

1

1ST1

21

11ST1

1ST1 1

3,42ST1

1,2

1

1, 1ST1

1

1

1,2,2ST1

1ST1

1

1, 1ST1

1,24ST1

1

1ST1 1

2

1

1

BP

Walter

Anadarko

Westport

Shell

El PasoEl Paso

Anadarko

EOG

MarathonEl Paso

Agip

Marathon

Shell

Shell

Marathon Marathon

DevonEnergy

Kerr-McGee

Marathon

Agip

Agip

McMoRan

Kerr-McGee

Marathon

AmeradaHess

Marathon

Agip

Agip

Walter

AmeradaHess

AmeradaHess

McMoRan

BP

Spinnaker

Pogo

Mariner

Agip

ChevronTexaco

ChevronTexaco

Agip Westport

261

282

260

283

G22759

785

259

285

287 286

786

871

G21738

32

75

G13091G22848

G06921 G06922 G19920

281

262

280

290

782

827

G21685

783

289

784

288

308

1003

960

872

959 961

873G22840

G05800

G19916

825

G22928G22927

G16449 G16450

G12136

828

291

G21161

G21162

279

G16455

G16448

781

33

914

76 77

35

78

1004 1005

G20036 G18333

1009

G12145

G18169

G12142 G18176

G18184

G22839

G16578

79

G2178483 84

G22849

G22841

913

957 958

1002

G12139G19918

G13075

869

915 916

875

G13084

G16678

G10968 G18188

G12144

962

1007

34

876

920

964 965

1008

874

963

1006

917 918 919

G22842

G21688

745

120119

G20037

G16679

G18189

G18324

G15539 G20029

39 40

80 81 82

3736 38

966

1010

878

787

832 833

789 790

834

G18177

921

877

788

826

870

G15447

G15343

829 830

G19836

G16454 G16453

G18165

G16466

118

744743

G18167

831

G16

452

G16

451

G16467

702701 S

G18168

G18170

G18273

G18284746

922

G18325

0 5

Km

400 metres

Green Canyon

OUTLINE

• INTRODUCTION

• CASE STUDY- Exploration Well Sidetrack

•DRILLING RESULTS

•PRODUCTION

• CONCLUSIONS

High Cost Of Simulation(in the past)

• Unix workstations and the Unix-based software

• Unix system support personnel required

• Need for experts in geological and flow modeling

Offshore Exploration Well

• Net Pay Lower Than Expected

• Other Uncertain Variables

• Sidetrack or Abandon ?

WELL DATA

Well Name TD MD TVD Results

EW 966 #1 Apr ’98

12,150

12,147

Marginal Oil Pay

Time Constraints

• Floating Rig - US $125,000 / day

• Time 4:00 p.m.

• Answer Needed by 12:00 noon the Next Day

Work Flow

• Received Data at 6:30 p.m.

• Engineer 1 - Reviewed data

• Engineer 2 - Built single well model - Determined sensitivity to rock

and fluid properties

• Engineer 3 - Digitized and grided maps - Calculated volumetrics - Exported grids to simulator

RESERVOIR DESCRIPTION OF BASAL NEBRASKAN SAND

Early Pleistocene ageLower Slope environmentPonded submarine fan complex sandsOil hydrocarbonsDefined by direct hydrocarbon indicators (amplitude anomaly) using 1996 Diamond Geophysical 3-D seismic volume.Accumulation trapped by fault, structural closure and minor stratigraphy.Excellent porosity, perm and low clay content.

Black Widow Amplitude Map

BASAL NEBRASKAN SAND STRUCTURE

Digitized Structure Map

Gridded Top-of-Structure Map

Water Saturation Contour Map at Initial Conditions

Water Saturation Cross-section at Initial Conditions

Model Building

A full-field flow model, including wells, faults and an aquifer was developed in four (4) hours.

Flow Rate and Cumulative Production

Water Saturation Contour Map After 4 Years

Water Saturation Cross-section After 4 Years

Study Results

4 case ran between 6 and 10 PM

7 additional what ifs ran next morning, varied:•geology•rock properties

All sidetrack drilling cases were economic

OUTLINE

• INTRODUCTION

• CASE STUDY- Exploration Well Sidetrack

•DRILLING RESULTS

•PRODUCTION

• CONCLUSIONS

WELL DATA

Well Name TD MD TVD ResultsEW 966 #1 Apr

’9812,15

012,14

7Marginal Oil Pay

EW 966 #1 ST1

May ’98

11,950

11,880

Oil Pay. Basal Nebraskan

Sand Productive.Completed. Producing.

ORIGINAL HOLE AND SIDETRACK

EW 966 #1 ST1 Log SectionBasal Nebraskan Sand Penetration

EW 966 #1 ST1 Processed Log

Basal Nebraskan Sand

Black Widow N-S Seismic LineN S

OH

ST1

DISCOVERY WELL SUMMARYBASAL NEBRASKAN SAND

MEI EW 966 #1 ST1 drilled May ‘98– Encountered 56 NFP – 32 percent porosity– 13 percent water saturation– LKO - 11,495 ft TVDSS– Assumed OWC – 12,000 ft (HCI)

OUTLINE

• INTRODUCTION

• CASE STUDY- Exploration Well Sidetrack

•DRILLING RESULTS

•PRODUCTION

• CONCLUSIONS

PRODUCTION STATISTICS

First Production Oct 28, 2000.Initial BHP 8774 psi – SITP 5591 psiPeak Rate 10,500 Bpd, 8.8 MMcfpd– Oct 27, 2001

Through Jun 16, 2002– Producing 5440 Bopd, 4.6 MMcfpd– Cum 4398 MBo, 3.64 Bcf.– SIBHP 6420 psi - SITP 3067 psi

OUTLINE

• INTRODUCTION

• CASE STUDY- Exploration Well Sidetrack

•DRILLING RESULTS

•PRODUCTION

• CONCLUSIONS

CONCLUSIONS

A PC-based characterization and simulation system exists that allows for modeling of exploration wells while the rig is on-site.

CONCLUSIONS

PC-based characterization and simulation in conjunction with the appropriate user interface allows geoscientists and engineers to model reservoirs on a routine real-time basis.

CONCLUSIONS

Simulation should be an everyday tool that is used in applications as diverse as exploration well evaluations and full field studies.

CONCLUSIONS

The cost of PC-based simulation is low due to the lower costs of hardware, software and support.

Manpower costs are significantly lowered due to a powerful interface that reduces both the time to complete a study and the need for expensive simulation experts.