friday 2 nd of march 2012

Friday 2nd of March 2012

Photo courtesy of Howard Johnson

Wytch Farm Field Development Project

TEAM BMohammed Alshawaf , Lanray Hammed Bakare, Francsico J. Barroso Viseras, Aristeidis Karamessinis,Ha Nguyen and Shi Su

2

Introduction

11.8km

Wytch Farm Field

Google Earth, 2011

Cultural information• Location Dorset, Wessex Basin (50°69’,-1°98’)

44 km2, onshore and offshore• Environment outstanding beauty, tourism,

wild life

Geological overview• Reservoir Sherwood Sandstone• Seal Mercia Mudstone• Source Lias Formation• Play type Tilted fault blocks

Underhill & Stoneley, 1988Source

SealReservoir

Cultural information• Location Dorset, Wessex Basin (50°69’,-1°98’)

44 km2, onshore and offshore• Environment outstanding beauty, tourism,

wild life

Field appraisal

Depth 1585 mPressure 2400 psig

Oil column thickness 39 mAreal extend 40 km2

API gravity 38.1° @ 15°CGOR 320 scf/stb

P90 P50 P10

STOIIP (MMbbl) 580 795 1040

Reserves (MMbbl) 215 290 385

Geological overview• Reservoir Sherwood Sandstone.• Seal Mercia Mudstone• Source Lias Formation• Play type Tilted fault blocks

• Producers 1X-02, 1D-02• Appraisal wells 3• 3D seismic survey

Wytch Farm - Development phase - Team B

Aims and Objectives

Develop the geological model

Investigate viable development options

Assess associated static and dynamic uncertainties

Propose a development and production plan

Justify additional data acquisition requirements

3


Drive mechanism determination

• Limitations of material balance

• Oil expansion and aquifer drive are the most plausible• No assumption can be validated

4

0 20,000 40,000 60,000 80,000 100,0000

200

400

600

800

1000

1200

f(x) = 0.0040445729247098 x + 644.549764938038

Aquifer and solution gas

ΔP/Eo [psi.stb/rb]

F/Eo

[10^

6 st

b]

0 0.001 0.002 0.003 0.004 0.005 0.006 0.0070

500,000

1,000,000

1,500,000

2,000,000

2,500,000

f(x) = 276813886.39531 x + 340856.777006015

Solution gas and compaction drive

Eo + Ef [rb/stB]

F [r

b]

N=300 MMBblN=645 MMBbl

Deve

lop

mod

elIn

vesti

gate

op

tions

Asse

ss u

ncer

tain

ties

Prop

ose

plan

Justi

fy d

ata

acqu

isitio

n


Recovery mechanism

Primary recovery• Low primary recovery: 4.6%

=> secondary recovery methodsSecondary recovery• Water injection preferred• Gas injection not advised: under-saturated oil and low GOR

Possibility of using artificial lift

5

Deve

lop

mod

elIn

vesti

gate

op

tions

Asse

ss u

ncer

tain

ties

Prop

ose

plan

Justi

fy d

ata

acqu

isitio

n

Building the simulation model

• Main assumptions

– Input Fine model (2.5M cells)– Upscaled properties Φ, facies, Kh and Kv

– Fluid model Dead oil, relative permeabilities Capillary pressure neglected for simplification purposes– Output coarse model (82,000 cells, 8 faults)

6Coarse horizontal permeability model within Flooding event 1Fine horizontal permeability model within Flooding event 1

Fine hor. permeability model - Sector Coarse hor. permeability model - Sector

Deve

lop

mod

elIn

vesti

gate

op

tions

Asse

ss u

ncer

tain

ties

Prop

ose

plan

Justi

fy d

ata

acqu

isitio

n


Upscaled model consistency

7

Static properties

Geology

Volumetrics

Upscaled properties

kh, kv

Φ

Facies

Dynamic properties

Cumulative production

Bottom-hole pressure

Oil saturations

Sweep efficiency

Water cut

Coning water

Numerical diffusion

Deve

lop

mod

elIn

vesti

gate

op

tions

Asse

ss u

ncer

tain

ties

Prop

ose

plan

Justi

fy d

ata

acqu

isitio

n

Coarse model consistency(history match)

• Oil rates: good match• Water rates: calibrate the model

• Limits: well history, no flow controlWytch Farm - Development phase - Team B 8

Deve

lop

mod

elIn

vesti

gate

op

tions

Asse

ss u

ncer

tain

ties

Prop

ose

plan

Justi

fy d

ata

acqu

isitio

n

Development strategy

Parameter Constraint Solution

Drilling strategy

Number of wells Recovery factor vs economics

25 producers / 10 injectors

Schedule Rates and rigs 2 wells/m

Well location Geology and oil distribution Uniform

Production strategy

Plateau Maximise recovery & 5% recovery 3-year plateau

Water injection Pressure maintenance After 15 m

Production time Lease 25 years

9

Deve

lop

mod

elIn

vesti

gate

op

tions

Asse

ss u

ncer

tain

ties

Prop

ose

plan

Justi

fy d

ata

acqu

isitio

n


10

Development strategy results

• 3-year plateau• Injection starts after 15

months• 345 MMBbl recoverable• 43% recovery factor

based on P50

STOIIP 795 MMBblRecovered 345 MMBbl

STOIIP (MMBbl)

Recovered (MMBbl)

Recovery factor

P90 580 239 41%

P50 795 345 43%

P10 1 040 452 43%

Deve

lop

mod

elIn

vesti

gate

op

tions

Asse

ss u

ncer

tain

ties

Prop

ose

plan

Justi

fy d

ata

acqu

isitio

n

Sweep efficiency analysis

11

Water breakthroughStart of water injection

• Injection after 15 months• 89% sweep efficiency achievable over 25 years

Deve

lop

mod

elIn

vesti

gate

op

tions

Asse

ss u

ncer

tain

ties

Prop

ose

plan

Justi

fy d

ata

acqu

isitio

n


Uncertainty analysis

12

• Approach combines both static and dynamic parameters

• Parameters considered

GRVPorositySw

kH, kV

Corey parametersSor, Swc, Swcr

Transmissibilities

Static properties

Dynamic properties

GRV

Oil relative permeability

Horizontal permeability

Oil residual saturation

Connate water saturation

Vertical permeability

Porosity

Water saturation

Water relative permeability

Faults transmissivity

Critical water saturation

-35% -25% -15% -5% 5% 15% 25% 35%

Tornado ChartDeviation basecase cumulative production (%) De

velo

p m

odel

Inve

stiga

te

optio

nsAs

sess

unc

erta

intie

sPr

opos

e pl

anJu

stify

dat

a ac

quisi

tion

Reducing uncertainties

Data acquisition plan Reprocess seismic data Coring of the first few wells

SCAL Logging Fluid analysis

GRV

Oil relative permeability

Horizontal permeability

Oil residual saturation

Connate water saturation

Vertical permeability

-35% -25% -15% -5% 5% 15% 25% 35%Deviation from base case (%)

Deve

lop

mod

elIn

vesti

gate

op

tions

Asse

ss u

ncer

tain

ties

Prop

ose

plan

Justi

fy d

ata

acqu

isitio

n

Wytch Farm - Development phase - Team B 14

Conclusions

Number of wells 25 producers / 10 injectors

Drilling schedule 2 wells/mWell location Uniform

Plateau 3-year plateau

Water injection After 15 mProduction time 25 years

High recovery factor

High sweep efficiency

Only water injection used

Good understanding of

uncertaintiesRecovered (MMBbl) Recovery factor

P90 239 41%

P50 345 43%

P10 452 43%


Thank you

Any questions ?


Geology and upscaled properties: facies

Fine grid Coarse grid Deve

lop

mod

elIn

vesti

gate

op

tions

Asse

ss u

ncer

tain

ties

Prop

ose

plan

Justi

fy d

ata

acqu

isitio

n


Volumetrics QC

17

2.8%1.4%

0.8%

Deve

lop

mod

elIn

vesti

gate

op

tions

Asse

ss u

ncer

tain

ties

Prop

ose

plan

Justi

fy d

ata

acqu

isitio

n


Upscaled properties: kh

Fine grid

18

Coarse grid

Deve

lop

mod

elIn

vesti

gate

op

tions

Asse

ss u

ncer

tain

ties

Prop

ose

plan

Justi

fy d

ata

acqu

isitio

n


Upscaled properties: Φ

Porosity distribution: Fine vs Coarse grid

Deve

lop

mod

elIn

vesti

gate

op

tions

Asse

ss u

ncer

tain

ties

Prop

ose

plan

Justi

fy d

ata

acqu

isitio

n

%


Cumulative production

- Fine grid

- Coarse grid

Deve

lop

mod

elIn

vesti

gate

op

tions

Asse

ss u

ncer

tain

ties

Prop

ose

plan

Justi

fy d

ata

acqu

isitio

n


Bottom-hole pressure

- Fine grid- Coarse grid

Injectors Producers

Deve

lop

mod

elIn

vesti

gate

op

tions

Asse

ss u

ncer

tain

ties

Prop

ose

plan

Justi

fy d

ata

acqu

isitio

n


Oil saturations

Fine grid Coarse grid

Deve

lop

mod

elIn

vesti

gate

op

tions

Asse

ss u

ncer

tain

ties

Prop

ose

plan

Justi

fy d

ata

acqu

isitio

n

23

0 0.1 0.2 0.3 0.4 0.5 0.6 0.70

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0.4

0.45

Coarse Fine One to One line

tD (pore volume injected)

NpD

(por

e vo

lum

e pr

oduc

ed)

Sweep efficiency


Deve

lop

mod

elIn

vesti

gate

op

tions

Asse

ss u

ncer

tain

ties

Prop

ose

plan

Justi

fy d

ata

acqu

isitio

n


Water cut

24

- Fine grid

- Coarse grid

Deve

lop

mod

elIn

vesti

gate

op

tions

Asse

ss u

ncer

tain

ties

Prop

ose

plan

Justi

fy d

ata

acqu

isitio

n


Coning water


Deve

lop

mod

elIn

vesti

gate

op

tions

Asse

ss u

ncer

tain

ties

Prop

ose

plan

Justi

fy d

ata

acqu

isitio

n


Numerical diffusion


Deve

lop

mod

elIn

vesti

gate

op

tions

Asse

ss u

ncer

tain

ties

Prop

ose

plan

Justi

fy d

ata

acqu

isitio

n


History match per well

Deve

lop

mod

elIn

vesti

gate

op

tions

Asse

ss u

ncer

tain

ties

Prop

ose

plan

Justi

fy d

ata

acqu

isitio

n

28

Rig #Rig-1

Rig-2

Rig-1

Rig-2

Rig-1

Rig-2

Rig-1

Rig-2

Rig-1

Rig-2

Rig-1

Rig-2

Rig-1

Rig-2

Rig-1

Rig-2

Rig-1

Rig-2

Rig-1

Rig-2

Rig-1

Rig-2

WFP-19

WFP-1

To January 1, 2037

WFP-13

WFP-10

WFP-11

WFP-5

WFP-21

WFP-16

WFP-14

WFP-23

WFP-24

WFP-7

WFP-2

WFP-18

WFP-9

WFP-17

WFP-4

WFP-16

WFP-22

WFP-12

WFP-20

Dec-12

WFP-8

Jun-12 Jul-12 Aug-12 Sep-12 Oct-12 Nov-12Dec-11 Jan-12 Feb-12 Mar-12 Apr-12 May-12

Drilling schedule

Priority based on rate and rig location (two rigs: E, W)

Deve

lop

mod

elIn

vesti

gate

op

tions

Asse

ss u

ncer

tain

ties

Justi

fy d

ata

acqu

isitio

nPr

opos

e pl

an


Well location

Well positioning based on the geology and the properties (kh)

Deve

lop

mod

elIn

vesti

gate

op

tions

Asse

ss u

ncer

tain

ties

Prop

ose

plan

Justi

fy d

ata

acqu

isitio

n


Water injection strategy

Water injection after 15 months in order to ensure pressure maintenance

Deve

lop

mod

elIn

vesti

gate

op

tions

Asse

ss u

ncer

tain

ties

Prop

ose

plan

Justi

fy d

ata

acqu

isitio

n


Buckley-Leverett analysis

0.3 0.35 0.4 0.45 0.5 0.55 0.6 0.65 0.7 0.75 0.80

0.10.20.30.40.50.60.70.8

Relative Permeability Graph

krwkro

Sw

Kr

0.3 0.35 0.4 0.45 0.5 0.55 0.6 0.65 0.7 0.75 0.80

0.2

0.4

0.6

0.8

1

1.2Fractional Flow Curve

fwTangent Line

Sw

fw

0 1 2 3 4 5 60.3

0.350.4

0.450.5

0.550.6

0.650.7

0.750.8

Sw against VD

VD

Sw

0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 20

0.2

0.4

0.6

0.8

1NPD Against tD

One to One Line

1-Swc-Sor

Buckley-Leverett

Simulation

tD

NPD

Deve

lop

mod

elIn

vesti

gate

op

tions

Asse

ss u

ncer

tain

ties

Prop

ose

plan

Justi

fy d

ata

acqu

isitio

n


0.3 0.4 0.5 0.6 0.7 0.8 0.9 10

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1Relative permeability

Krw - Corey water:1.5Krw - Corey water: 1.8Krw - Corey water:5Kro - Corey oil/water:2Kro - Corey oil/water: 2.5Kro - Corey oil/water:5.5

Sw

Kr

Relative permeability analysis

Deve

lop

mod

elIn

vesti

gate

op

tions

Asse

ss u

ncer

tain

ties

Prop

ose

plan

Justi

fy d

ata

acqu

isitio

n

friday 2 nd of march 2012

Documents