Kachi Onyeagoro, Frans Van der Vlugt, Steve Naruk, Mark ...archives.aapg.org/committees/research/rdrg2006/3Onyeagoro.pdf · Shell Exploration & Production GEOLOGISTS AND RESERVOIR

Shell Exploration & Production

GEOLOGISTS AND RESERVOIR ENGINEERS

SHOULD BE FRIENDS!!!!

Kachi Onyeagoro, Frans Van der Vlugt, Steve Naruk, Mark Barton & Steve Jolley


STRATIGRAPHY AND SIMULATION

STRUCTURAL AND SIMULATION

INTRODUCTION

STRUCTURAL, STRATIGRAPHY AND SIMULATION


Well 4

Low NTG Upper Sand (27%)

Well 5

Well 5

Well 4

High NTG Upper Sand (76%)GEOLOGISTS ARE ALWAYS HAPPY!!!

NO HISTORY MATCH!!

Well 5

INTRODUCTION

CAN’T GET A HISTORY MATCH!!


RESERVOIR ENGINEERS WHEN HAPPY!!!!Case 2: Fault Tr =0, t = 14 yr

Case 1: Fault Tr =1, t = 14 yr

RESERVOIR ENGINEERS WHEN UNHAPPY!!!!

THEY GET A HISTORY MATCH!! Or PREDICT….

INTRODUCTION


SRM w/ seismic-scale faults …. Sheet sands …..

+ +

+

Industry standard fault perms Manzocchi, ’99; Petrel defaults ….

0 . 00 01

0 .0 01

0. 01

0 .1

1

10

1 00

0 0.1 0 .2 0 .3 0 .4 0 .5 0 .6 0 .7 0 .8 0 .9 1

G o ug e c o m p o s itio n

Faul

t Rx P

erm

(mD)

8 , 0 0 0

8 , 5 0 0

9 , 0 0 0

9 , 5 0 0

1 0 , 0 0 0

1 0 , 5 0 0

1 1 , 0 0 0

0 1 / 0 5 / 9 8 0 7 / 2 4 / 9 8 0 2 / 0 9 / 9 9 0 8 / 2 8 / 9 9 0 3 / 1 5 / 0 0Example typical well performance1500 psi decline over 6 months2500 psi decline over 2 yrs

EXPECT TO PRODUCE 15-30MBLS/D FROM MULTIPLE WELLS

“ I t ’ s a t a n k o f s a n d ” !DISCOVERY/APPRAISALINTRODUCTION – How we model!!


It’s the stratigraphy…

It’s the fault rock properties…. It’s differential

depletion and compaction…

0

1000

2000

3000

4000

5000

6000

7000

8000

9000

10000

11000

J-00

J-00

M-00

A -00

M-00

J-00

J-00

A-00

S -00

O-00

N-00

D-00

J-01

J-01

M-01

A-01

M-01

J-01

J-01

A-01

S-01

O-01

N-01

D-01

J-02

F-02

M-02

A-02

M-02

J-02

J-02

A-02

S-02

O-02

N-02

D-02

J-03

F-03

M-03

A-03

M-03

J-03

J-03

A -03

FTPr

essu

re (p

sig)

Field Performance Issues…INTRODUCTION

Why Did We Fail?…

Shell Exploration & Production STRUCTURAL MODELING NIGHTMARES DO HAPPEN!!


1 km

Golden rule when Golden rule when modellingmodelling structurally complex structurally complex reservoirsreservoirs

Ensure structure-seismic and geometrical consistency throughout seismic interpretation & static-dynamic modelling process…



Build fault model with structurally validated geometries (seismic display in FAPS, but cross-reference to Seisworks also direct link via Openworks). Import to TrapTester, QC and Edit Horizon-Fault Intersection



Dynamic model faults back-loaded to Static model

Seismic domain fault polygons

Static model

Importance of realistic fault geometryImportance of realistic fault geometry

• Geometry in dynamic model is a poor representation of seismic and static model

• Over 225 simulations runs –no history match

– Huge number of ad hoc edits

–Even tried increasing permeability of layers increasing by 5 fold



Seismic domain fault polygons

Dynamic model faults back-loaded to static model

Static model

Importance of realistic fault geometryImportance of realistic fault geometry• Geometry in

dynamic model made representative of seismic and static model

• Only 70 simulations runs to achieve history match

• No major ad hoc edits required (e.g. no multipliers in reservoir permeability required)



Importance of realistic fault propertiesImportance of realistic fault properties

• TMs calculated based on realistic fault properties (permeability and thickness)

• Note that large variation in TM along fault plane

• Variation in TMsrealistic unlike when single TM per fault is used



Faults in BHI logs

Example “subtle faults” in horizontal well

Subtle faultsSmallest resolvable fault block ≈ 10 acres

Detailed structural, BHI and attribute analyses shows, additional, “subtle” faults

Faults in BHI logs


Faults in BHI logs




Detailed structural, BHI and attribute analyses shows, additional, “subtle” faults



Capillary entry pressure modeling

I m p o r t a n c e o f c o n s i d e r i n g m u l t iI m p o r t a n c e o f c o n s i d e r i n g m u l t i -- p h a s e f l o wp h a s e f l o w

• A b o v e p e t r o l e u m w a t e r c o n t a c t t w o o r m o r e p h a s e s m a y b e p r e s e n t i n p o r e s p a c e

• I m p o r t a n t t o t a k e i n t o a c c o u n t r e l a t i v e p e r m e a b i l i t y , w h i c h v a r i e s a s a f u n c t i o n o f p h a s e s a t u r a t i o n ( i . e . h e i g h t a b o v e f r e e w a t e r l e v e l )

cross-

fault fl

ow

no cro

ss-fau

lt flow

top reservoir

Petroleum saturation in fault zone

Height

above

free-w

ater le

vel

1 0

1

1

1

1

2

Petroleum saturation in fault zone

Relativ

e perm

eability

1 0

1

3

4

1

0

1

1

1 & 2

4

3

krwkrp

3

1

1

4

3

2

AT THIS POINT, WE HAVE BEATEN THE STRUCTURAL & FAULT ISSUES TO DEATH!!!!!!



PETREL TRADITIONAL CHANNEL MODEL,CHANNELS NOT STACKED IN GEOLOGIC ORDER

ENSURE PETREL CHANNELS ARE STACKED IN GEOLOGIC ORDER


Shell Exploration & Production STRATIGRAPHY AND SIMULATION

Sheet/Shoreface sandsUse Available data toDistribute the shales

Shell Exploration & ProductionCo

pyrig

ht 20

01

SIEP

B.V

.

M e a n d er b e l t X s ect io n @ w e l l

Sh o w in g m ea n d er b e l t a n d e r o d e d h o le s

M eander Be lt Bas e D rape

Channel Base Drape

I nterbed shales

STRATIGRAPHY AND SIMULATIONChannel sands

Use Available data toDistribute the shales


Channel base drape (b lue)

Channel base d is c onform i ty (red)

Channel base d is c onform i ty(red s urfac e)

Channel base d is c onform i ty (red)



Conv ergent c hannel m arg in

Channel base lag (orang e)

Channel base lag (orang e)

Core – Log calibration

Image log and core work flow for interpreting sub-seismicreservoir architecture

Copy

right

2001

SI

EP B

.V.

M a tch 9 0_9 0 _2 ca se, M a tch BU

1E-3 0.01 0. 1 1 10 100 1000 1000010

100

1000

Log-Log plot: dp and dp' [psi ] vs dt [hr]

Sk in -0.32 --

Pi 13731.3 psia

k.h 9730 md .ft

k 139 md

S - No Flow 278 ft

E - No Flow 285 ft

N - No Flow 99.2 ft

P.T ANALYSIS


Europa “L ” Sa nd: MD GC S tar D iagra mGEOCHEMICAL FINGERPRINTING

KKh

SkinBoundaries


3rd Order2nd Order1st OrderChannel / Inter-channel

ArchitectureChannel Base Drapes

Channel Margin

Mud Filled Channels

Intra-channel Shales

Infill Architecture

Focus on the Shale Architecture

Ways to Study and Mitigate - Stratigraphy

3rd Order2nd Order1st OrderChannel / Inter-channel

ArchitectureChannel Base Drapes

Channel Margin

Mud Filled Channels

Intra-channel Shales

Infill Architecture

Focus on the Shale Architecture

Ways to Study and Mitigate - StratigraphySTRATIGRAPHY AND SIMULATION

Shell Exploration & ProductionC

opyr

igh

t 20

01

SIE

P B

.V.

Cop

yrig

ht 2

003

S

IEP

B.V

.

Turbidite s tra tigra phic archi te cture - 1s t orde r corre lation a ppe ars laye r cak eDeta ils from c ore, d ip m eter, se ism ic indica te chan ne ls and shale dra pes

N O R TH

SO U T H

A- 3

A- 1 ST

A- 2ST 1 93 5- 1 BP1

9 35 - 1ST 1

93 5- 2

9 34 -1

A- 2O H

U n it A

Sheet (pond ed)

U n it B

Sheet (pond ed)

U n it C

Sheet (pond ed)

U nit D

C hannel (hea led)



Why Stra tigraphic Com partm enta liza tion - c hannel & Res ervoir perform ance be haviour

Reservoir sw eepReduced recovery

Dead ends, pockets of oil only connected via one path to p roducers/ energy source, bypa ssingM ore edges of reservoir, interaction with g ravity

Different W ater/ G as breakthroughFluid mixing, different flooding speeds through different paths

Reservoir pressureLonger/ shorter path -> reservoir pressure d istribution change

De a d e nd s, p oc k et s of oi l on ly c on ne c ted v ia on e pa th to p ro du c er

(Sha le D ra p es )

F lu id m ix in g, d iffe re nt flo od in g s pe e ds throu gh di ffe re n t p ath s

(D eg ree of Am a lg a ma tion )

Ed ge s o f re s erv oi r, inte rac tion w ith g ra v ity (S inu os i ty)

C B D ra pe

Why Stra tigraphic Com partm enta liza tion - c hannel & Res ervoir perform ance be haviour

Reservoir sw eepReduced recovery

Dead ends, pockets of oil only connected via one path to p roducers/ energy source, bypa ssingM ore edges of reservoir, interaction with g ravity

Different W ater/ G as breakthroughFluid mixing, different flooding speeds through different paths

Reservoir pressureLonger/ shorter path -> reservoir pressure d istribution change

De a d e nd s, p oc k et s of oi l on ly c on ne c ted v ia on e pa th to p ro du c er

(Sha le D ra p es )

F lu id m ix in g, d iffe re nt flo od in g s pe e ds throu gh di ffe re n t p ath s

(D eg ree of Am a lg a ma tion )

Ed ge s o f re s erv oi r, inte rac tion w ith g ra v ity (S inu os i ty)

C B D ra pe



Copy

right

2001

SI

EP B

.V.

Copy

right

200

3 SI

EP B

.V.

C om b in ed struc tu ral a nd strat features to gethe r a cco un t for pe rfo rm anc e

S RM w / su btle fau lts … .Amalg am ated Ch ann els + Sh eets … ..

+ +

Actual Bh p’s

+

Sh eet (p on ded )Sh eet (p on ded )

Ama l. ch a n ne lsAma l. ch a n ne ls

Sim u lated Bh p ’s⇒New fault p erm s fu n ctio n … .

⇒

Y ield s ~ HM in m ultip le w ells from “1st

p rin cip les”

0.00 01

0 .0 01

0.01

0.1

1

10

0 001 0 01 0 1 1

Faul

t Rx

Perm

(mD)

lo gK f= f( K h ,Go u g e co mp )

Man zo cc hi 9 9

STRUCTURAL, STRATIGRAPHY AND SIMULATION

Documents

Kachi Onyeagoro, Frans Van der Vlugt, Steve Naruk, Mark ...archives.aapg.org/committees/research/rdrg2006/3Onyeagoro.pdf · Shell Exploration & Production GEOLOGISTS AND RESERVOIR