single-well sagd: overcoming permeable lean zones and...

Single-Well SAGD: Overcoming Permeable

Lean Zones and Barriers

Grant Hocking1, Travis Cavender2 & John Person2

1GeoSierra 2Halliburton

SPE148832

Canadian Unconventional Resources ConferenceCalgary, Alberta Canada 15-17 November, 2011

Thermal Enhanced Bitumen Recovery

Conventional SAGD– Reduced Steam Pressure

• Shallow depth, Caprock integrity, Outcrop proximity

– Geological Issues• Vertical Perm, Shale barriers, Lean zones

Conventional CSS– Geological Issues

• Bottom water, Caprock integrity, Top gas

Single-Well SAGD– Engineer around Geology

• High permeable propped vertical planes• Operate in SAGD mode

Conventional SAGD

Conventional CSS

Single-Well SAGD

Slide 2

Weakly Cemented Formations

Hydraulic Fracturing– Conventional

• Strong, Hard Rocks – Brittle Fracture– Frac & Pack

• Weak, Soft Sediments – Ductile Process

Weakly Cemented Formations– Minimal Cementation, Soft & Weak– Stress State

• Force Chains Fragile– Easily Destroyed– Minor Vibration or Shearing– Grain Contact Dissolution– Over-Pressurization

• Minimal Formation Stress Contrast– Stress Contrast can not be maintained

over geological time– Constitutive Behavior

• Ductile Frictional Behavior• Anelastic

Isotropic Compression Force Chains Shown

Minor Shear Strain Destroys Force Chains

Force Chains Destroyed

Slide 3

Early Field Trials of Azimuth Control

1990

1991 1991

Required Azimuth(String Line)

Required Azimuth(String Line)

Plane CoalescenceBeneath Surface

Plane Orientated AlongRequired Azimuth

1991 1991

Slide 4

Azimuth Control Initiation Devices

1991 1996

Prototype 1st Generation

1997

2nd Generation

Single Azimuth Tools

Slide 5

SENW

Cross-Section

Plan View

Azimuth Control Iron Propped Planes

Deep PRB

Upper PRB

Pilot PRB

FormerPump & TreatFacility

Location IP-10 (F52-F53)

0

2

4

6

8

10

12

14

16

18

20

16.0 16.5 17.0 17.5 18.0 18.5 19.0 19.5 20.0 20.5 21.0Corrected Horizontal Distance (ft)

Res

istiv

ity (O

hm) Inclined Wall Thickness interpreted

to be approximately 4.8-inches

Slide 6

Multi-Azimuth Vertical Planes

Each individual Plane Initiated & Propagated by Dedicated Tubing

Diametrically Opposite Cavities are Dilated to Initiate Azimuth Controlled Vertical Planes

Slide 7

Milk River Tight Gas Field Trials

100km

AlbertaSaskatchewan

Four (4) propped wings

Shoreline Anisotropy

4-1/2” J55 Casing

Slide 8

Single-Well SAGD System

Sump

Top Pay

Bottom Pay

Operated in SAGD Mode- no startup - shallow or deep

Injector

Producer

Slide 9

Single-Well SAGD Completion

Casing Liner Composite

9-5/8” 7”

Epoxy Ceramic

Legend

Cementing Shoe

X-Drain Casing

Orientating Mule Shoe

Slotted Liner

CompletionBlanket Gas

Steam4-1/2” VIT Produced Liquids

2-7/8” or 3-1/2”

Slotted Liner

Slide 10

Thermal Simulation Model Idealization

Modeled Region

Steam InjectionProduced Oil

Lines of Symmetry

1/2 Well SpacingWing Length

TRS-Thermal Simulator Athabasca Bitumen Sp=1,750kPa and 1,200kPa

Slide 11

Athabasca Bitumen Sp=1,750kPa

Slide 12

Single-Well SAGD in Channel Sand

Athabasca Bitumen Sp=1,750kPa Time (days)

Oil

Pro

duct

ion

Rat

e(b

bls/

day)

Cum

mul

ativ

eO

il(M

Mbb

ls)

Cum

ulat

ive

SO

R

0 500 1000 1500 2000 2500 3000 35000

100

200

300

400

500

600

0

0.2

0.4

0.6

0.8

1

1.2

0

1

2

3

4

5

Oil RateCum OilCSOR

50%

Single-Well SAGD

Slide 113

4x Single-Well vs Conventional SAGD

Athabasca Bitumen Sp=1,750kPa Time (days)

Oil

Pro

duct

ion

Rat

e(M

bbls

/day

)

Cum

mul

ativ

eO

il(M

Mbb

ls)

Cum

ulat

ive

SO

R

0 500 1000 1500 2000 2500 3000 35000

0.5

1

1.5

2

2.5

3

0

1

2

3

4

0

1

2

3

4

5

50% 50%

S-W SAGDConv SAGD

Single-Well SAGD Conventional SAGD

Faster Recovery

Slide 14

Single-Well SAGD Clean-Dirty Sands

Time (days)

Oil

Pro

duct

ion

Rat

e(b

bls/

day)

Cum

mul

ativ

eO

il(M

Mbb

l)C

umul

ativ

eS

OR

0 500 1000 1500 2000 2500 30000

100

200

300

400

500

600

0

0.2

0.4

0.6

0.8

1

1.2

0

1

2

3

4

5

Oil RateCum OilCSOR

Clean SandKv=2DKv=0.8DKv=0.4D

Single-Well SAGD Clean Sand Dirty Sand


Slide 15

Single-Well SAGD Shale Barrier

Time (days)

Oil

Pro

duct

ion

Rat

e(b

bl/d

ay)

Cum

mul

ativ

eO

il(M

Mbb

l)C

umul

ativ

eS

OR

0 500 1000 1500 2000 2500 30000

100

200

300

400

500

600

0

0.2

0.4

0.6

0.8

1

1.2

0

1

2

3

4

5

Oil RateCum OilCSOR

Clean SandKv=2DBarrier HolesK=200mDBarrier HolesK=20mD

Single-Well SAGD


Slide 16

Permeable Lean Zone

Water SaturationTemperature 0.1day

Temperature 1day

Temperature 6daysTemperature 30days

Temperature 90days

T °CPermeable lean zone


Slide 17

T °C


Slide 18

Conclusions• Process not depth limited

• Reservoir simulations indicate performance almost invariant of geology

• As built issues– Skin between coalesced vertical planes– Permeability of planes needs to be high

• In placed permeability• Maintain permeability over time

– Steaming trials required to quantify issues

AcknowledgementsDale Walters, Taurus Reservoir Solutions for reservoir simulationsSuncor, for access & field support of Milk River trials

Slide 19

single-well sagd: overcoming permeable lean zones and...

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