Review of Thermal Recovery Technologies for the Clearwater and Lower Grand Rapids

Formations in the Cold Lake Area in Alberta

Qi JiangBruce Thornton

Jen Russel-Houston Steve Spence

Osum Oil Sands Corp.

CIPC Paper 2009-068

Outline

• Commercial Thermal Projects in Cold Lake

• Reservoir Characteristics of Taiga Project

• Recovery Process Selection for Taiga Project

• Performance Forecast for Taiga Project

• Conclusions

•CSS has been commercial since mid 1980s in Clearwater

•IOL and CNRL have a combined thermal production of over 220,000 Bbl/d (mostly from CSS)

•SAGD has been tested in Clearwater since mid 1990s

•Two commercial SAGD projects by Husky and Shell are still in the early stage

•One commercial SAGD project in Lower Grand Rapids by CNRL in Wolf Lake

Commercial Thermal Recovery in Cold Lake

CSS and SAGD are two commercially applied processes

Comparison of Reservoir Properties

ProjectOperato

rZone

Depth (m)

Avg ϕK

(μm2)Soi(%)

NetPay (m)

Cold Lake IOL CLWTR 400 32 1-4 70 18-70

Wolf Lake CNRL CLWTR 485 33 2.5-4 47-59 10-42

Tucker Lake

Husky CLWTR 450 33 1-5 55-69 30-60

Primrose* CNRL CLWTR 500 322.9-3.2

41-75 7-29

Burnt Lake*

CNRL CLWTR 500 32 2-4 65-70 10-30

Orion* Shell CLWTR 425 35 3-5 60-64 20-27

Taiga Osum CLWTR 440 32-35 1-4 65-70 10-21

Wolf Lake CNRL LGR 400 33 3.2 75 10-14

Taiga Osum LGR 365 33 3-5 75-80 10-22

* Analogue to Taiga Clearwater

Recovery Processes in Cold Lake

• Primary Thermal Recovery Process– Cyclic Steam Stimulation (CSS)

– Steam Assisted Gravity Drainage (SAGD)

• CSS Follow-up or Enhancement Process– Pressure Up and Blow Down (PUBD)

– Mixed Well Steam Drive and Drainage (MWSDD)

– Vapor Extraction (Vapex)

– Liquid Addition to Steam for Enhanced Recovery of Bitumen (LASER)

– HPCSS Assisted SAGD and Hybrid Process

HPCSS in Clearwater Formation– Horizontal and vertical wells

– Injection at fracture pressure

– 60 m to 180 m spacing for horizontal wells

– 2 to 8 Acre spacing for vertical wells

– Development as low as 7 m net pay

– In areas generally with no to minimal bottom water or top gas

– CSOR: 3.3 to 4.5

– Predicted Ultimate recovery:15 to 35%

SAGD in Clearwater and Lower Grand Rapids Formations

– Horizontal Well Pairs (700 to 1000 m)

– Operating pressure 3 to 5 MPa, Burnt Lake SAGD was started with higher operating pressure close to dilation pressure

– 75 m to 120 m spacing

– Development to as low as 10 m net pay

– In areas with or without bottom water

– CSOR: 2.8 to 4.0 (at 100% quality)

– Predicted ultimate recovery: 45% to 55%

Performance of Thermal Projects (From 2008 ERCB Performance Presentation)

ProjectOperato

rZone

Bottom

Water

(m)

Tech-nology

Commercial since

Well Type

Current Oil Rate (B/d)

Current SOR

Cum. SOR

Cold Lake

IOL CLWTR N/A CSS 1985 VW & HW 140,000 3.3 3.3

Wolf Lake

CNRL CLWTR N/A CSS 1984 VW & HW 5,000 - 6.0

Primrose CNRL CLWTR N/A CSS 1992 HW 62,000 5.0 4.4

Burnt Lake

CNRL CLWTR N/A SAGD Pilot HW 700 4.9 3.7

Wolf Lake

CNRL LGR 0-2 SAGD 2001 HW 5000 3.7 4.2

Orion Shell CLWTR 0-10 SAGD 2006 HW 2,000 8.0 4.0

Tucker Lake

Husky CLWTR 5-20 SAGD 2006 HW 2,500 13.0 -

Majority of thermal production is from CSS

Recovery Factor and Cum. SOR (From 2008 ERCB Performance Presentation)

25

55

45

25 25

35

50

11.4

45.5

18.0

15.0

10.0

23.0

36.0

4.3 3.7 4.25.9 5.2

3.3 3.8

0

10

20

30

40

50

60

PrimroseCSS

Burnt LakeSAGD

WL B10SAGD

WL HWCSS WL ValleyFill CSS

IOL ColdLake CSS

Hilda LakeSAGD

CS

OR

(m

3/m

3) a

nd

RF

(%

)

Ultimate Recovery

Current Recovery

Cum. SOR

Ultimate recovery: 25-35% for CSS and 45 to 55% for SAGD

Fuel Required for 1.0 m3 CWE Steam

2.0

2.1

2.2

2.3

2.4

2.5

2.6

2.7

0 2 4 6 8 10 12 14 16 18

Pressure (MPa)

Fu

el R

equ

ired

, G

j p

er M

3 S

team

1.14

1.16

1.18

1.20

1.22

1.24

1.26

1.28

Rat

io

be

twee

n 1

00%

an

d 7

5 %

qu

alit

y

100% Injection Quality75% Injection QualityRatio between 100% and 75%

15 to 25% more fuel required to increase steam quality from 75% to 100%

CSS vs. SAGD

• SAGD – Generally higher recovery – Better justified SOR at higher recovery factor– Requires higher vertical to horizontal permeability ratio

– Applicable in areas with thick bottom water or top gas

• CSS– Generally lower recovery factor– Lower SOR initially– More robust and tolerate to heterogeneities– Not applicable in areas with thick bottom water or top gas

Reservoir characteristics and fluid Contacts are the keys for Selection of Recovery Process

Osum’s Taiga Project

Clearwater and Lower Grand Rapids

Reservoir Characteristics in Taiga Project

gas cap

basal water

M1

M2

S1

S2

6-26type well

6-26type well

Bottom Water

Gas Cap

M1 is beneficial for areas with top gas and M2 for areas with bottom water

Performance for Taiga Project

• Analogs

– Clearwater Formation: • CSS: CNRL’s Primrose

• SAGD: Burnt Lake and Shell’s Orion

– Lower Grand Rapids Formation: • CNRL’s B10 SAGD at Wolf Lake

• Reservoir Simulation

– 3D geostatistical model

Recovery Process Selection

• Lower Grand Rapids Formation:

– SAGD due to presence of bottom water

• Clearwater Formation:

– SAGD for areas with no or minimal M1 mudstone or with bottom water or top gas

– CSS for areas with continuous M1 mudstone and no bottom water

3-D Modeling for Lower Grand Rapids Formation

Pair 4

Pair 1

Bottom Water

Transitional Zone

SAGD producers should be placed 2-3 m above Bottom Water

Pair 1

Pair 4

3-D Modeling for Clearwater Formation

S2 Sand

M1 Mudstone

S1 Sand

SAGD Chamber

Kv in M1 mudstone determines accessibility of S1 sand

(At 5 Years of SAGD)

Effect of M1 Permeability on SAGD Performance

0

1

2

3

4

5

6

7

8

9

0 50 100 150 200 250

Cumulative Oil Production (1000 x m3)

Mon

thly

Ave

rage

SO

R (

m3/

m3)

With Continuous M1Without M1 or M1 Permeable

Economic Cutoff at SOR of 6.0

(At 5 years of SAGD from model with M1 permeable)

Operating Strategy to take advantage of geomechanic effects

Operating Pressures

• Lower Grand Rapids SAGD:• Steam chamber at 2.0 to 3.0 MPa in balance with bottom water pressure

• Clearwater:– SAGD:

• Steam chamber at 3 to 4 MPa during normal operations

• Injection pressure close to dilation for a short period is anticipated in some areas to enhance vertical permeability

– CSS: • Injection at fracture pressure is required to access top S1 sand by breaking through M1 mudstone layer

Conclusions (Cold Lake Area)

• HP CSS is a proven commercial recovery process for the Clearwater Formation

• Pilot test of SAGD has been success and applied commercially in the Clearwater Formation

• Vertical permeability, thickness and extension of bottom water or top gas will be the major factors affecting the selection of recovery process between CSS and SAGD for Clearwater

• SAGD has been proven to be a commercial viable process for Lower Grand Rapids Formation

Conclusions (Taiga)

• SAGD will be applied in Osum's Lower Grand Rapids due to the presence of thick bottom water.

• High pressure assisted SAGD and HPCSS will be considered for Clearwater Formation. Low pressure SAGD will be considered for the areas with bottom water or top gas.

• In some areas of the Clearwater in the Taiga project, operating SAGD at a pressure close to the dilation pressure is necessary to enhance SAGD performance.

• For Lower Grand Rapids Formation, over 50% recovery is predicted using SAGD at a CSOR of 3.0 to 3.5

• For Clearwater Formation, 35 to 55% recovery and CSOR of 3.5 to 4.2 are predicted for SAGD

Acknowledgement

• Permission from Osum Oil Sands Corp. to publish the results from the Taiga project

• Statistical modeling and geological interpretation from Shawna Christensen of Throndson Energy Ltd. and John Carey of Petrel Robertson Consulting Ltd.