building & expanding the ula...

Building & Expanding the Ula WAG

DEVEX, 13 May 2010 Sigrun Mellemstrand, Eirik Espe, Becki van Gestel, Masoud Haajizadeh, Simon Thomas, Ingrid E.I. Øxnevad BP Norge AS

2

Ula Field

•  Overview

•  Field History

•  Current WAG Scheme

•  Future WAG Scheme

•  Summary

Overview Field History Future WAG Summary

Ekofisk

Tambar

ULA

Gyda

A b e r d e e n

S t a v a n g e r

L o n d o n

U l a E k o f i s k

E m d e n T e e s i d e

Current WAG

ULA

3

Ula Facts

•  Ula Ownership:

−  80% - BP (operator)

−  20% - DONG E&P Norge AS

•  On stream: 1986

•  Tambar Field tie-in: 2001

•  Blane Field tie-in: 2007

•  Oselvar tie-in: 2011

•  STOOIP

−  ~1 billion stb (160 mill Sm3)

•  Produced as of 01-01-10

−  440 mmstb oil (70 mill Sm3)

ULA

TAMBAR

Living Q

Drilling Production

BLANE

Overview Field History Future WAG Summary Current WAG

Blane Tambar

4

Ula Structure

•  Elongated four-way salt induced dip closure

•  Reservoir dips between 0 and 10o

−  Lower dips at the crest and to the south (0 to 5o)

•  A NW-SE fault system bisects the structure

•  Shallower oil-water contact in west flank

•  Reservoir depth: 3350-3800m TAMBAR

EF OWC - 3800m

NF OWC - 3560m

WF OWC - 3500m

NE

SW

NESW

Unit 1

Unit 2+3Triassic

3350

3500

3650

3800

3200

NESW

Unit 1

Unit 2+3Triassic

3350

3500

3650

3800

3200


5

•  oAPI ~ 40 •  T res ~295o F (146o C) •  Pb ~ 2300 psi (159 bar) •  P init ~ 7100 psi (490 bar) •  P res ~ 6300 psi (434 bar) •  MMP ~ 5000 psi (345 bar) •  GOR ~ 500 scf/stb (89 m3/m3) •  Visco ~ 0.35 cp •  Viscw ~ 0.33 cp •  Bo ~ 1.36 rb/stb (@Pb) •  C1 in Injection Gas ~ 68%

Ula Fluids

Satu

ratio

n

1 0

Fractional Distance

Ula Gas and Oil saturations

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

0 100 200 300 400 500 600 700 800 900 1000

Distance from injector, ft

Ula Gas and Oil Density

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

0 200 400 600 800 1000

Distance from injector, ft

g/cm

3

Ula Slim Tube Simulation - Vaporizing Drive

1 0

0 1

500 grid blocks100 grid blocks 20 grid blocks

Den

sity

gr/c

c

oil

gas

Impact of Grid Size on Distributions of Phase Saturation and Density at 0.5 PVI

oil

gas

Miscible WAG Works Well in Ula •  High SORW (35 - 50%) •  Under-saturated oil •  Pres: 6300 > MMP: 5000 psi


6

Reservoir Units

~ 10

0 m

Ula

Fo

rmat

ion

Perm (mD)

Upper Jurassic, shallow marine sandstones

Baffle between Unit 1A2 & 1A3

Capable of holding

>1000 psi (70 bar)

<5cm

Current WAG

Unit 1 Hor.

Producers

Unit 3 WAG

Injectors

1A11A21A31B

1-101-202-255-100

3

20-4000

20-200

10-100

2

2-15

4390

4400

4410

4420

4430

4440

4450

4460

4470

4480

4490

4500

DEPTH

METRES

3500

3510

3520

3530

3540

3550

3560

TVD

METRES

SW_2V/V1 0

Fluids A16A Initial After WF Future

Sorw ~ 35-50%

Sorm ~ 5-10%

Water

Gas/Water

Oil

Ula Stratigraphy Overview Field History Future WAG Summary Current WAG

Baffle in lower Unit 2

Capable of holding >35 psi

7

0.0

20000.0

40000.0

60000.0

80000.0

1986

1987

1988

1989

1990

1991

1992

1993

1994

1995

1996

1997

1998

1999

2000

2001

2002

2003

2004

2005

2006

2007

2008

2009

2010

00.5

11.5

22.5

33.5

4

0.050000.0100000.0150000.0200000.0250000.0

1986

1987

1988

1989

1990

1991

1992

1993

1994

1995

1996

1997

1998

1999

2000

2001

2002

2003

2004

2005

2006

2007

2008

2009

2010

00.10.20.30.40.50.60.70.80.91

020406080100120140

1986

1987

1988

1989

1990

1991

1992

1993

1994

1995

1996

1997

1998

1999

2000

2001

2002

2003

2004

2005

2006

2007

2008

2009

2010

WCUT

WI s

tart

s

WA

G s

tart

s

Tam

bar

tie

d-in

Mor

e W

AG

co

nver

sion

s

Onl

ine

10

year

s af

ter

disc

over

y

arrested decline

WA

G o

il in

all

W

AG

pr

oduc

ers

Uni

t 1

prod

uctio

n st

arts

Sha

rp d

eclin

e

WA

G S

tudi

es

140 0

250 0

80 0

1 0

Oil Rate mbd

WI Rate mbd

GI Rate mmscfd GOR scf/stb

Ula Historical Profiles Overview Field History Future WAG Summary Current WAG

0.0

20000.0

40000.0

60000.0

80000.0

1986

1987

1988

1989

1990

1991

1992

1993

1994

1995

1996

1997

1998

1999

2000

2001

2002

2003

2004

2005

2006

2007

2008

2009

2010

00.5

11.5

22.5

33.5

4

3600 0

Firs

t dee

p ho

rizon

tal

inje

ctor

Production increase

Beh

ind

flood

-fro

nt c

ore

8

•  Appropriate water handling capacity à upgraded in 1992 and 1994

•  Reservoir pressure above minimum miscibility pressure (~5000 psi / 345 bar)

•  Appropriate gas handling capacity à 120 mmscfd gas processing (3.4 mill Sm3)

•  Gas compression à installed in 1993-1994 for gas lift

•  Gas supply à Re-inject gas after export route via Cod Field lost. Tambar, Blane and Oselvar tie-in.

•  Conversion of water injectors to gas (WAG) injectors

0

50000

100000

150000

200000

250000

Oct-‐86

Oct-‐88

Oct-‐90

Oct-‐92

Oct-‐94

Oct-‐96

Oct-‐98

Oct-‐00

Oct-‐02

Oct-‐04

Oct-‐06

Oct-‐08

Prod

uction

& in

jection

0

1000

2000

3000

4000

5000

6000

7000

8000

Res

ervo

ir Press

ure

Injected Water, bpdProduced Water, bpdReservoir Pres s ure, ps i

Requirements to build the Ula WAG Overview Field History Future WAG Summary Current WAG

9

WAG Injector Water injector Unit 1 Producer WAG Producer

A04

A09A

A13A

A07C

A17B A15A

A18

A12A

Current WAG Scheme

•  3 vertical WAG producers up-dip −  1 shut-in

•  3 vertical WAG injectors down-dip −  1st injector converted in 1997 −  3 additional injectors in 2001/ 2002 following

Tambar tie-in −  New WAG injector behind WAG flood front (A09A)

in 2006 •  1 horizontal WAG injector in Unit 3 •  1 vertical water injector down-dip

−  Integrity problems with gas injection •  Current injection capacity

−  Gas handling: 120 mmscf/d gas (3.4 mill Sm3) −  Gas injection: 90 mmscf/d gas (2.5 mill Sm3),

limited by wells −  Water handling: 160,000 bbl/d water (25,400 Sm3) −  Water injection: 50,000 bbl/d water (11000 Sm3),

limited by injection pump

Ula Top Structure Map


10

Ula WAG Sectors

•  Large sectors (1km – 2.5 km)

•  Sectors identified through tracer program

−  Originally with water tracers (waterflood sectors)

−  Verified with gas tracers (WAG sectors)

•  Initial breakthrough times

−  Water: 11 to 55 months

−  Gas: 15 to 35 months

•  3 tracer injections in 2010


Waterflood sectors

WAG sectors 50/22 Tracer travel time, months

11

02468

1012141618

1996

1998

2000

2002

2004

2006

2008

2010

Oil rate (mstb/d)

0

2

4

6

8

10

1994

1996

1998

2000

2002

2004

2006

2008

2010

Oil Rate mstb/d)

0

2

4

6

8

10

1999

2001

2003

2005

2007

2009

Oil rate (mstb/d)

N

A18

A15/A15A

A12A

(~1600 m3/d)

WAG Works in Ula

•  Historically 5-10 mbd of WAG oil (800-1600 Sm3/d)

−  25-50% of Ula production

•  Currently ~20 mbd WAG oil, ~60-70 % of Ula production

•  Total WAG oil: ~18 mmstb (2.9 mill Sm3)

•  Current scheme, including the contracted Oselvar gas, will recover over 7% of STOOIP


12

Ula Gas Injection

•  128 bscf of injected gas (3.6 bill Sm3) −  ~20% recycled gas

•  WAG oil produced from all 4 sectors

−  Indicated by gas tracer data and confirmed by well test results •  Limited sweep in lower perm Unit 3

−  Verified by PLTs in injectors while on gas and water injection

−  New injectors target Unit 3


WAG Efficiency:

~7 mscf gas / bbl oil

(~0.8 Sm3 oil / kSm3 gas) 10

20

30

40

50

60

70

80

1998

1999

2000

2001

2002

2003

2004

2005

2006

2007

2008

2009

Gas

Injection, m

msc

fd

A13A: 39 bcfA09A: 14 bcfA07C : 36 bcfA04: 11 bcfA03A: 24 bcf

WAG InjectorWater injectorUnit 1 ProducerWAG ProducerWAG Sector

A15A

A18

A12A

A04

A09A

A13A

A07C

A17B


A15A

A18

A12A

A04

A09A

A13A

A07C

A17B



A15A

A18

A12A

A15A

A18

A12A

A04A04

A09A

A13A

A07C

A09AA09A

A13A

A07C

A17BA17B

13

2009 Drilling Campaign

•  A-12A recompleted. Came online in June 2009, with higher oil rate than expected, and very high GOR.

•  A-15A redrilled close to original A-15, online in November 2009.

−  High initial production rates.

−  Accumulation of mobilized oil


A12A oil rate and GOR from well tests

0

1000

2000

3000

4000

5000

6000

7000

8000

9000

10000

Jan-99 Jan-01 Jan-03 Jan-05 Jan-07 Jan-09

Oil

Rat

e [s

tb/d

], gr

een

0

1000

2000

3000

4000

5000

6000

7000

8000

9000

10000

GO

R [s

cf/b

bl],

red

Oil rateGOR

WAG effect from A07C

DHSV repair

TTAC

A15 oil rate and GOR from well tests

0

2000

4000

6000

8000

10000

12000

14000

16000

18000

Jan-96 Jan-98 Jan-00 Jan-02 Jan-04 Jan-06 Jan-08 Jan-10

Oil

Rat

e [s

tb/d

], g

reen

0

1000

2000

3000

4000

5000

6000

7000

8000

GO

R [s

cf/b

bl],

red

Oil rateGOR

WAG effect from A13A

WAG effect from A03A

Recompletion

DHSV failure

14

WAG Surveillance

Key to Evaluating Benefits of WAG

•  Gas tracer injection and sampling

•  PLT in injectors

•  Weekly WC measurements

•  Monthly well tests

•  Continuous THP monitoring

−  Injectivity

−  WAG slug identification

•  A09A core in mature WAG sector

•  4D seismic being evaluated

A03A PLT

3 injection

zones

W-12 (A12A)

60

65

70

75

80

85

90

95

02.ja

n.02

01.m

ar.0

218

.apr

.02

21.ju

n.02

11.se

p.02

04.d

es.0

202

.feb.

0315

.mar

.03

07.m

ai.03

18.ju

n.03

19.ju

l.03

03.se

p.03

09.o

kt.03

15.n

ov.0

327

.des

.03

05.fe

b.04

13.m

ar.0

413

.apr

.04

05.m

ai.04

09.ju

n.04

22.ju

l.04

25.se

p.04

05.n

ov.0

423

.des

.04

03.fe

b.05

17.m

ar.0

530

.apr

.05

09.ju

n.05

21.ju

l.05

14.se

p.05

26.o

kt.05

08.d

es.0

528

.jan.

0611

.mar

.06

20.a

pr.0

631

.mai.

0629

.jul.0

609

.sep.

0620

.okt.

0610

.des

.06

Date

wate

rcut

(vol

%)

watercut

A12A WC


15

WAG InjectorWater injectorUnit 1 ProducerWAG Producer

A15A

A18

A12A

A04

A09A

A13A

A07C

A17B



A15A

A18

A12A

A15A

A18

A12A

A04A04

A09A

A13A

A07C

A09AA09A

A13A

A07C

A17BA17B

Data acquisition behind WAG flood front

Extensive Data Acquisition Program in 2006 •  A09A was drilled in a mature WAG sector •  Reservoir was cored & logged −  To evaluate effectiveness of current WAG scheme −  To quantify Sor distribution

•  101 meters of core (100% core recovery) •  Performed extensive study program −  Over 800 core plugs taken for analysis

−  Routine core & fluid sample analysis −  Sw and GC, (well site and lab plugs) −  SCAL m & n, Rw from w/s plugs −  Log Analysis

30cm20cm 20cm15cm 15cm30cm20cm 20cm15cm 15cm


16

Moving to Expanded WAG (XWAG)

•  Successful current WAG scheme in Ula

−  Clear indication of mobilized oil production

−  ~ 18 mmstb incremental oil produced

•  Extensive data acquisition in A09A to evaluate effectiveness of WAG

−  Clear indication of reduction of Sor

Current WAG


Expanded WAG

•  Simulation studies on Expanded WAG

−  Indicate potential for a healthy additional incremental recovery

−  Maximize recovery with Unit 3 horizontal injectors


A15A

A18

A12A

A04

A09A

A13A

A07C

A17B

WAG18

WAG16

WAG15

WAG8

WAG13

WAG1


A15A

A18

A12A

A04

A09A

A13A

A07C

A17B



A15A

A18

A12A

A15A

A18

A12A

A04A04

A09A

A13A

A07C

A09AA09A

A13A

A07C

A17BA17B

WAG18

WAG16

WAG15

WAG8

WAG13

WAG1


A15A

A18

A12A

A04

A09A

A13A

A07C

A17B


A15A

A18

A12A

A04

A09A

A13A

A07C

A17B



A15A

A18

A12A

A15A

A18

A12A

A04A04

A09A

A13A

A07C

A09AA09A

A13A

A07C

A17BA17B

17

XWAG Screening

A-13A

A-3A

A-4

A-7C

A-10A

A-12A

A-14A

A-15

A-17A

A-18

A-1B

7/12-2

7/12-3

7/12-3A

7/12-4

7/12-6

7/12-7

7/12-8

7/12-9

A-1

A-10

A-12

A-13

A-14

A-16

A-16A

A-17

A-1A

A-2A

A-3

A-5

A-5A

A-7

A-7B

A-8

A-8AA-9

A-11

Legend

Oil Producer

Water Injector

WAG Injector

S uspended or Abandoned

Well trajectory

-‐3828 m ssl FWL

-‐3756 m ssl FWL

-‐3714 m ssl FWL

-‐3528 m ssl FWL

-‐3557 m ssl FWL

X-WAG Horisontal Injector

WAG 1

WAG 2

WAG 3

WAG 4

WAG 5

WAG 6

WAG 7WAG 8

WAG 9

WAG 10

WAG 11

WAG 12

Possible pre-Producers.

WAG 13

WAG 14

WAG 15

WAG 16

WAG 17

WAG 18

Reserves by 2020 for s ingle well cases , constant gas injection of 60 mmscfd

A-13A

A-3A

A-4

A-7C

A-10A

A-12A

A-14A

A-15

A-17A

A-18

A-1B

7/12-2

7/12-3

7/12-3A

7/12-4

7/12-6

7/12-7

7/12-8

7/12-9

A-1

A-10

A-12

A-13

A-14

A-16

A-16A

A-17

A-1A

A-2A

A-3

A-5

A-5A

A-7

A-7B

A-8

A-8AA-9

A-11

Legend

Oil Producer

Water Injector

WAG Injector

S uspended or Abandoned

Well trajectory

-‐3828 m ssl FWL

-‐3756 m ssl FWL

-‐3714 m ssl FWL

-‐3528 m ssl FWL

-‐3557 m ssl FWL

X-WAG Horisontal Injector

WAG 1

WAG 2

WAG 3

WAG 4

WAG 5

WAG 6

WAG 7WAG 8

WAG 9

WAG 10

WAG 11

WAG 12

Possible pre-Producers.

WAG 13

WAG 14

WAG 15

WAG 16

WAG 17

WAG 18

Reserves by 2020 for s ingle well cases , constant gas injection of 60 mmscfd

25 XWAG targets screened and ranked according to recoverable resources


7 XWAG targets chosen for recoverable resources, and location (sweep)


A15A

A18

A12A

A04

A09A

A13A

A07C

A17B

WAG18

WAG16

WAG15

WAG8

WAG13

WAG1


A15A

A18

A12A

A04

A09A

A13A

A07C

A17B



A15A

A18

A12A

A15A

A18

A12A

A04A04

A09A

A13A

A07C

A09AA09A

A13A

A07C

A17BA17B

WAG18

WAG16

WAG15

WAG8

WAG13

WAG1

2 XWAG targets chosen for recoverable resources, location, drillability from existing slots, & good geologic understanding


A15A

A18

A12A

A04

A09A

A13A

A07C

A17B

WAG16

WAG14


A15A

A18

A12A

A04

A09A

A13A

A07C

A17B



A15A

A18

A12A

A15A

A18

A12A

A04A04

A09A

A13A

A07C

A09AA09A

A13A

A07C

A17BA17B

WAG16

WAG14

18

XWAG Enablers

•  2006: A09A WAG injector drilled & cored behind flood front (10% Sorm)

•  2007-2008: Increase gas handling capacity with Ula Gas Upgrade (UGU)

−  Gas handling 60 mmscfd à 120 mmscfd (3.4 mill Sm3/d)

•  2007: Identify locations & slots for 2 new WAG injectors

•  2007-2008: Investigate passive downhole flow control for uniform injection in horizontal wells

•  2008-2010: Replace water injection pumps à 140,000 bbls/d (22k Sm3/d)

•  2008: Commitment to purchase Oselvar gas volumes from 2011

•  2009: Bring back 2 WAG Producers

•  2010: First XWAG type well drilled Blane

Tambar MPP

Tambar East

Tambar Base

Oselvar

Future gas for Ula WAG Scheme:

>150 bcf


19

XWAG Plans Overview Field History Future WAG Summary Current WAG

2013

-201

9 •  Potential for 5 more horizontal injectors −  Install new wellhead platform

−  Continue injection in Unit 3 with long, horizontal wells

2019

+

•  Evaluate additional sources of gas for long term

•  Full project has potential to increase recovery by ~10% of STOOIP −  Bring total recovery to ~70%

through technology •  Enable Ula to produce past 2028

2009

-201

2

•  2 new horizontal injectors in Unit 3 (2010&2012)

−  Target deeper injection in Unit 3

−  Long, horizontal injectors ~1000m with passive downhole flow control & isolation packers for uniform injection


A15A

A18

A12A

A04

A09A

A13A

A07C

A17B

WAG16

WAG14


A15A

A18

A12A

A04

A09A

A13A

A07C

A17B



A15A

A18

A12A

A15A

A18

A12A

A04A04

A09A

A13A

A07C

A09AA09A

A13A

A07C

A17BA17B

WAG16

WAG14

20

XWAG Challenges and Mitigations

•  Commerciality - high early investment and late pay-back

−  Project phasing

−  3rd Party tie-ins (Oselvar)

•  Completion conformance

−  Passive downhole flow control

−  Evaluation of concept needed

•  Reservoir response prediction

−  Comprehensive uncertainty analysis to understand range of outcome

•  Life of field surveillance plan

−  Surveillance commitment



A15A

A18

A12A

A04

A09A

A13A

A07C

A17B

WAG18

WAG16

WAG15

WAG8

WAG13

WAG1


A15A

A18

A12A

A04

A09A

A13A

A07C

A17B



A15A

A18

A12A

A15A

A18

A12A

A04A04

A09A

A13A

A07C

A09AA09A

A13A

A07C

A17BA17B

WAG18

WAG16

WAG15

WAG8

WAG13

WAG1

21

Summary

•  Ula forms a strategic hub in the Norwegian North Sea

−  Successful tie-ins of Tambar, Blane, tie-in of Oselvar in 2011

•  Miscible WAG is an effective process in Ula

−  Clear indication of mobilized oil production from WAG producers

−  Clear indication of reduced Sor (down to 10%) in WAG flooded zone from A09A core/log data

−  Recovery increased and lifetime extended

•  WAG Expansion will realize a healthy additional incremental recovery of ~10% STOOIP

−  Enables production at current levels beyond license period of 2028


0

140

1986

1987

1988

1989

1990

1991

1992

1993

1994

1995

1996

1997

1998

1999

2000

2001

2002

2003

2004

2005

2006

2007

2008

2009

2010

WI GI/WAG

arrested decline

Acknowledgements

Thanks to BP Norge AS and DONG E&P Norge AS for allowing this information to be shared. Thanks the Ula team, Eirik Espe, Becki van Gestel, Masoud Haajizadeh, Simon Thomas, Ingrid E.I. Øxnevad

building & expanding the ula...

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