Enhanced Oil Recovery Slides-11

7/24/2019 Enhanced Oil Recovery Slides-11

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Tayfun Babadagli, PhD, PEng Short Course - EOR File-111

FIELD CASES DRY IN-SITU COMBUSTION

MOCO T Midway-Sunset field

After Gates and Sklar (JPT, Aug. 1971)


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ISC initiated in Jan. 1960

injecting air at 2,000 Mscf/D

into two wells

Spontaneous ignition occurred

after 18 days.

Immediate production response

by increasing the productionto 2,850 BOPD in Feb. 1960.

Four additional wells added to

distribute air better.

After Curtis, SPE 18809

Peak at 4,200 BOPD

Air injection at 8,000 Mscf/D


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Ultimate rec. Estimated = 50-57 % OOIP

at cumulative iar of 85-90 Bscf

Remaining life 12-15 years at the rate of

5,000 Mscf/D

After Curtis, SPE 18809


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SUPLACU de BARCAU FIELD ROMANIA: Largest in-situ combustion project

After Carcoana, SPE 20248

ISC selected as steam generators were not available

PILOT: Eight ~10 acre 9-spot patterns


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SUPLACU de BARCAU FIELD ROMANIA


Expanded towards north and line drive

Combustion front = 5 miles by 1990

120,000 MMscf/D of air being

injected into 100 injectors


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PLAN: To displace the combustion front downdip

Production well converted into injectors when

combustion front breaks into the production well.


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Oil production=10,400

B/D in 1987, 600 wells

were affected by ISC

Average A/O = 9.5-

11.3 Mscf/bbl in 1973-

1989

It increased to 14.2Mscf/bbl after 1985

Ultimate recovery

expected = 53 %

OOIP



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SPE 1003461. Clastic, NW Romania

2. Drilled first in 1956, heavy viscous oil

3. First production 1961

4. 1960-1970 most wells drilled

5. 1963-1970 steam and fireflood tested

800 wells

1,200 tones/day production

In 35 years, cumulative oil = 17.8 million tones

RF = 44.6%

Primary expectation was 9% in 80 years

In-situ combustion = 60% recovery in pilot (to improve, water injection, air rate optimization, bett

control of combustion front.

EXPECTATIONS and CONCLUSIONS after the PILOT:

Need well stimulation

40% ISC recovery

Continuous combustion is better than pattern

Sweep from top to bottom (parallel to isobaths)


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SPE 100346RESERVOIR

D = 35-200 m

Dip = 5-8 degree

Net pay = 4-24

Initial pressure = 4-22 bar Initial T = 18 C

Porosity = 32%

Initial oil = 85%

K = 2 D

Oil vis. = 2,000 cP

Oil density = 960 kg/ cu m. Area = 1,700 ha

PRODUCTION

Initial rates, 2-5 cu m/d decreased quickly to 0.1-0.3 cu m/d

ISC started in 1970

Production wells were on cyclic steam stimulation


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Tayfun Babadagli, PhD, PEng Short Course - EOR File-11 10


SPE 100346

60,000

50,000

40,000

30,000

20,000

10,000

0

140,000

120,000

100,000

80,000

60,000

40,000

20,000

0

61 63 65 67 69 71 73 75 77 79 81 83 85 87 89 91 93 95 97 99 01 03 05

Years

61 63 65 67 69 71 73 75 77 79 81 83 85 87 89 91 93 95 97 99 01 03 05

Years

7,000

6,000

5,000

4,000

3,000

2,000

1,000

0

Air/OilRatio,scum/cum

Highest production

Total air injection rate maximum


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SPE 100346

60,000

50,000

40,000

30,000

20,000

10,000

0

140,000

120,000

100,000

80,000

60,000

40,000

20,000

0

61 63 65 67 69 71 73 75 77 79 81 83 85 87 89 91 93 95 97 99 01 03 05

Years

61 63 65 67 69 71 73 75 77 79 81 83 85 87 89 91 93 95 97 99 01 03 05

Years

7,000

6,000

5,000

4,000

3,000

2,000

1,000

0

Air/OilRatio,scum/c

um

Since 1979 : Linear ISC front was propagated down, parallel to isobaths and the process

expanded towards the west.

10 km E-W air injection wells are included, I-P distance = 100 m.

RF fro the entire pool = 50% estimated

1983: Second linear ISC front, parallel to the main one, was started in the middle portion and

eastern part.

1996: Second ISC front abandoned.

Since 1998: capacity reduced and decline started.


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SPE 100346LABORATORY

Oxidation cell

To study the phenomenon around the combustion front

To determine the parameters needed to design the project To determine

Air consumption per volume of rock

Deposited fuel per volume of rock

Ignition temperature

H/C ratio

Combustion tube tests

Basic data

Possibility to initiate and maintain a combustion front

Advancement speed of the combustion front

Spatial conformance of the burnt zone

Influence of operating parameters ( air flow, ignition temperature, oxygen concentration etc.)


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SPE 100346OPERATIONAL CHALLENGES

Well ignition:

Requirements are saturation with oxygen of the ignition zone and generating T

higher than 400 C Ignition methods are (a) combustible gases, (b) electrical, (c) chemical,

(d) chemical + electrical

KEY TECHNICAL CHALLENGES

Optimize injection rate Maximize oil rate

Reduce operation cost

Assess steam drive potential

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Enhanced Oil Recovery Slides-11