CHOA Presentation Nov 26

Thermal Wells: An Abandonment Perspective.

Will Butler, P.EngTeam Lead - Engineering

FundamentalsUnderstand current directives, regulations and IRP’s

AER Directive 009 (1990) • Sec. 3 • Sec. 4.2 • Sec. 5

AER Directive 010 (2009)

AER Directive 020 (2010) • Sec. 3 • Sec. 4.2 to 4.6• Sec. 5.1 & 5.4

ID 2003-01

Enform IRP Volume 03

FundamentalsUnderstand current directives, regulations and IRP’s

AER Directive 009 (1990) • Sec. 3 • Sec. 4.2 • Sec. 5

AER Directive 010 (2009)

AER Directive 020 (2010) • Sec. 3 • Sec. 4.2 to 4.6• Sec. 5.1 & 5.4

ID 2003-01

Enform IRP Volume 03

Common Non-compliance Issues Well is not properly isolated with thermal cement across oilsands

formations (internal or external to casing)

Casing/connections not suitable for potential thermal and pressure cycling stresses.

Zonal abandonment of producing intervals was not to current D020 standards

Casing failure/corrosion issues present

SCVF/GM exists

Case 1: Background Vertical well east of Fort McMurray

Rig Release: February 6, 1981

Zonally abandoned and well cut and capped

Compliant in 1981

Currently within 300m of a proposed SAGD project

Case 1: Compliance IssuesSurface cement plug

Prod. casing/connections are inadequate

Cemented with Class G with no returns to surface

BP capped with Class G

Non-routine waiver rejected by AER. Well must be made thermally compliant

Case 1: OperationsStep 1: Drill out surface plug & BP


Step 2: Run CBL/VDL to verify cement top and integrity

TOC 25m above sfc. csg shoe

Cement bond is good throughout



Step 3: Section mill & under-ream casing & cement from 109mKB to

below shoe @ 298mKB

AER Oilsands interval requiring thermal isolation



Step 3: Section mill & under-ream casing & cement from 109mKB to

prod. csg. Shoe @ 298mKB

Step 4: Spot continuous thermal cement plug from TD to min. 15m

above sfc. csg. shoe

Final Cost = $450K

Case 2: Background Vertical well south of Fort McMurray

Rig Release: January 11, 2000

Perfs @ McMurray, Wabiskaw & Clearwater formations

Well within proposed steam chamber targeting the McMurray

Client concerned casing may part due to thermal stress created by possible steam chamber contact

Case 2: Compliance Issues

Prod. casing/connections are inadequate

Casing cemented to surface with non-thermal thixotropic cement with good returns to surface (verified by CBL)

The following AER non-routine procedure approved based on engineering assessment of potential wellbore stresses due to steam chamber contact.

Case 2: OperationsStep 1: Remove 38.1mm coil tubing

strings and retrieve Packer @ 407mKB



Step 2: Retrieve WR plug @ 416mKB




Step 3: Chemically cut casing in the McMurray formation

@ 460mKB





@ 460mKB

Step 4: Run & set BP @ 459mKB





@ 460mKB

Step 4: Run & set BP @ 459mKB

Step 5: Spot continuous thermal cement plug from TD to min. 15m

above sfc. csg. shoe

Final Cost = $90K

Case 3: Background Vertical well north of Red Earth Creek

Rig Release: March 30, 1995

Well is not located within a proposed thermal development

Very little bitumen present in formations in this area

Case 3: Compliance IssuesProd. casing/connections inadequate?

Casing cemented to surface with Class G cement with good returns to surface (verified by CBL)

The following AER non-routine procedure was approved based on very little bitumen in formations and absence of thermal development in area

Condition: Should thermal operations develop within vicinity of the well, it must be remediated to a state that AER deems “thermally compatible”

Case 3: OperationsStep 1: Retrieve 60.3mm tubing

Case 3: OperationsStep 1: Retrieve 60.3mm tubing

Step 2: Spot continuous thermal cement plug from TD to surface

In Conclusion

Know and understand the applicable regulations for thermal areas

Generally, a well is not thermally compliant unless the requirements in D009, D010, D020 & ID 2003-01 are met (Case 1)

Wells may receive AER approval to abandon with alternative methods if sound engineering can be demonstrated (Case 2)

Wells that are non-thermal, but within oilsands areas, may receive AER approval to abandon to D020 requirements, with condition that should area become thermally active, well must be brought into thermal compliance with current regulations (Case 3)

Thank-You

Documents

CHOA Presentation Nov 26