Bert van der Meer, Senior Reservoir Engineer

CASTOR Meeting, Lyon, WP 3.3

K12-B Reservoir Engineering and Monitoring

Lyon, Wednesday, January 23, 2008K12-B Reservoir Engineering and Monitoring2

Outline

• Introduction• Reservoir Engineering

• History Match• Temperature Profile

• Monitoring• Tracer• Tubing integrity

• Conclusions

Lyon, Wednesday, January 23, 2008K12-B Reservoir Engineering and Monitoring3

K12-B monitoring programme

• Situation is considered as the best possible seal and leakage through it is considered highly unlikely.

• Monitoring is mainly focussed on the integrity of the wells…• and also on tracking CO2 migration and gas mixing in the reservoir.

• Downhole pressure and temperature• Tracers combined with production and injection rates• Downhole fluid chemistry• Geophysical logs• Seabed and shallow surveys*• Surface geochemistry*• Back-production tests*

* Ongoing activities, outside CASTOR

Lyon, Wednesday, January 23, 2008K12-B Reservoir Engineering and Monitoring4

Gas ProductionInitial Gas in Place: 14.4 BCM

Gas Produced (01/01/2007): 12.3 BCM

Remaining reserves: 0.4 BCM

CO2 content: 13 %

Amine wash down to 2% CO2

In production since 1987

Lyon, Wednesday, January 23, 2008K12-B Reservoir Engineering and Monitoring5

Introduction –Offshore Location

Lyon, Wednesday, January 23, 2008K12-B Reservoir Engineering and Monitoring6

Introduction –K12-B Compartments

• Single well compartment

• CO2 Injector and gas producer

Lyon, Wednesday, January 23, 2008K12-B Reservoir Engineering and Monitoring7

Introduction –Reservoir Engineering• Total system = two parts

• Well bore behavior (Poiseuille flow)• Reservoir flow (Darcy type of flow)

BHP from PB

THP, Q

BHP*, temp?

Lyon, Wednesday, January 23, 2008K12-B Reservoir Engineering and Monitoring8

TEST 1 History match past performance K12-B8

0

200000

400000

600000

800000

1000000

1200000

1400000

0 500 1000 1500 2000 2500

Time [days]

Gas

pro

du

ctio

n r

ate

[Nm

3/d

]

0.00

50.00

100.00

150.00

200.00

250.00

300.00

350.00

400.00

Pre

ssu

res

[bar

]

gas

w hp

BHPcal

OBSstat

Lyon, Wednesday, January 23, 2008K12-B Reservoir Engineering and Monitoring9

History match past performance (2)

0

200000

400000

600000

800000

1000000

1200000

1400000

0 500 1000 1500 2000 2500

Time [days]

Gas

pro

du

ctio

n r

ate

[Nm

3/d

]

0.00

50.00

100.00

150.00

200.00

250.00

300.00

350.00

400.00

Pre

ssu

res

[bar

]

gas

w hp

BHPcal

OBSstat

BHPest.

Lyon, Wednesday, January 23, 2008K12-B Reservoir Engineering and Monitoring10

History match past performance (3)

0

200000

400000

600000

800000

1000000

1200000

1400000

150 170 190 210 230 250250.00

255.00

260.00

265.00

270.00

275.00

280.00

285.00

290.00

295.00

300.00

305.00

310.00

315.00

320.00

325.00

330.00

335.00

340.00

345.00

350.00

gas

w hp

BHPcal

OBSstat

BHPcal

BHPest.

Lyon, Wednesday, January 23, 2008K12-B Reservoir Engineering and Monitoring11

Injection test

39

40

41

42

43

44

45

46

47

48

49

50

51

52

53

01-05-04 01-06-04 01-07-04 01-08-04 01-09-04 01-10-04 01-11-04 01-12-04 01-01-05 01-02-05

Time [date]

Bot

tom

hole

pre

ssur

e [b

ar]

Simulator P

Run 1 - P

Run 2 - P *

Run 3 - P

Run 4 - P

Run 5 - P *

Run 6 - P

Run 7 - P

Run 8 - P

Run 9 - P

Run 10- P

Lyon, Wednesday, January 23, 2008K12-B Reservoir Engineering and Monitoring12

Temperature profile wellbore

0

20

40

60

80

100

120

140

30 32 34 36 38 40 42 44

Pressure [bar]

Tem

pera

ture

[deg

.C]

Upwards run

Downwards run

Lyon, Wednesday, January 23, 2008K12-B Reservoir Engineering and Monitoring13

Temperature profile wellbore

Lyon, Wednesday, January 23, 2008K12-B Reservoir Engineering and Monitoring14

Temperature profile wellbore (2)

-0.04

-0.03

-0.02

-0.01

0

0.01

0.02

0.03

0.04

0.050 5000 10000 15000 20000 25000 30000 35000

Time [sec]

Der

ivat

ive

0

20

40

60

80

100

120

140

Tem

pera

ture

[d

eg.C

] / P

ress

ure

[bar

]

Deriv. Temp

Deriv. Pres

temp [deg.C]

pressure [bar]

event. Line

Lyon, Wednesday, January 23, 2008K12-B Reservoir Engineering and Monitoring15

Temperature effects

Subsurface heated-up by gas production

Lyon, Wednesday, January 23, 2008K12-B Reservoir Engineering and Monitoring16

Tracers

PMCP1,3-PDMCH

fluorine

carbon

PMCP1,3-PDMCH

fluorine

carbon

2 tracers arrive at nearest well (~420m) after about 4 months

PMCP & 1,3-PDMCH - K12-B1

0

5E-11

1E-10

1,5E-10

2E-10

2,5E-10

3E-10

3,5E-10

4E-10

4,5E-10

5E-10

01-m

ars-0

5

01-m

ai-05

01-ju

il-05

31-a

oût-0

5

31-o

ct-05

31-d

éc-05

02-m

ars-0

6

02-m

ai-06

02-ju

il-06

01-se

pt-06

Con

cent

ratio

n (L

/L)

PMCP1,3-PDMCH

Tracers used to monitor front movement of injected native CO2

Lyon, Wednesday, January 23, 2008K12-B Reservoir Engineering and Monitoring17

Tubing integrity logsRepeated after 1 year: log differences.

Combinations of corrosion or erosion mechanisms usually cause a dramatic increase in the rate of metal loss compared to the summation of separate mechanisms

2005 – 2006 - 2007

Lyon, Wednesday, January 23, 2008K12-B Reservoir Engineering and Monitoring18

Conclusions

• CO2 injection first time in the Netherlands• Past performance modeled and explained• CO2 injection without problems and as

predicted• CO2 breakthrough is slow and gradual

• For info: www.k12-b.nl

Lyon, Wednesday, January 23, 2008K12-B Reservoir Engineering and Monitoring19

Acknowledgements

• GDF Production Nederland B.V. and partners- EXPRO North Sea- DRC

• Dutch Government (CRUST, CATO, MONK)

• European Commission (CASTOR, CO2GEONET)