Understanding and Mitigating

Well-Integrity Challenges in a

Mature Basin

David Hardie, Anita Lewis

Senior Advisors

September 29, 2015

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2

Surface Casing Vent Flow (SCVF) & Gas Migration (GM)

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Outline

Well demographics

Well-integrity challenges

Life cycle approach to mitigate

challenges

3

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Wells: Stages

of the Life

Cycle

4

Western Canada British Columbia, Alberta, and Saskatchewan

By year-end 2015, there will be 600 000 wells

drilled in western Canada

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Well Integrity

Issues:

What Are We

Seeing?

5

Types of wellbore leakage:

• SCVF and GM (8 per cent)

• Casing failures (2 per cent)

• Abandonment plug failures

(2 per cent)

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Factors

Influencing

SCVF/GM

6

Geography and geology

Primary cementing

Well deviation

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Wells with Reported SCVF/GM

7

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Influence of

Cement Top

8

Cement at Surface

Total SCVF/GM

12.1%

SCVF

11.5%

GM

0.5%

SCVF & GM

0.1%

Total SCVF/GM

4.5%

SCVF

3.9%

GM

0.5%

SCVF & GM

0.1%

Low Cement Top Cement top below surface casing shoe

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Assessing

Risk

9

0

10

20

30

40

50

60

70

<1 1-9.9 10-99.9 100-299 300-1000 >1000

Pe

rce

nta

ge (

%)

Flow Rates (m3/d)

Alberta British Columbia

Non-Serious Serious

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Alberta: Evolving Well Designs

10

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

1995 1997 1999 2001 2003 2005 2007 2009 2011 2013

Per

cen

t o

f w

ells

dri

lled

Year

Deviated % Slant % Horizontal % Vertical %

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Influence of

Deviation on

Well Integrity

11

Active & Inactive Wells

All wells had reported cement returns to surface during

drilling of the well.

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Alberta:

Leakage in

Abandoned

Wells

12

Prior SCVF/GM

Regulatory requirements

Age of well

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Alberta:

Leakage in

Abandoned

Wells

13

16%

6% 6%

Historic leak No historic leak Not likelytested/reported

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Alberta:

Leakage in

Abandoned

Wells

14

Impact of Regulatory Requirements

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Alberta:

Leakage in

Abandoned

Wells

15

Leaking Abandoned Wells by Age

44%

6%

27%

9%

14%

0%

5%

10%

15%

20%

25%

30%

35%

40%

45%

50%

Pre 1966 1966 -1975 1976 -1985 1986 -1997 After 1997

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What are the

Risks?

16

Fugitive emissions

Groundwater contamination

Spills

Public safety

Credibility of regulator

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Well Integrity:

How Are We

Addressing

the Issue?

17

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Well Integrity:

How Are We

Addressing the

Issue?

Directive 079: Surface

Development in Proximity to

Abandoned Wells

• Management versus repair

Draft IRP # 25: Primary and

Remedial Cementing

• Improving well construction

practices

Assessing risks through pilot

projects and data-driven

modelling

18

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Well-

Integrity Risk

Assessment

Model

19

Well Risk

Well Integrity & Operations

Consequence

Well Construction

& Design

Mitigating Well Integrity Risks

20

Directive 020:

Well Abandonment

Directive 079: Surface

Development in Proximity to

Abandoned Wells

Abandoned Well Integrity

Assessment Project

DACC IRP 25 – Cementing

CSA – New well standard

AER Rules & Directives

IRP24: Hyd. Fracturing

AER URF Initiative

Frac Focus

Well Information Management System

SPE: Various Initiatives

Mitigating Well Integrity Risks

Assessment of leakage risk

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Building a

Healthy and

Sustainable

Energy Sector

21

Liability

Management

Long-Term

Public

Protection

Regulatory

Initiatives

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