Well Integrity Overview

Well Integrity – what does it all mean!

Definition of Well Integrity

Well Integrity is the Design, Installation, Operation and Maintenance of all Well Equipment to a standard that ensures the Safe Containment of

Produced Well Fluids & Injectants for the Life of the well.

Keep the hydrocarbons in the pipe !

Why is Well Integrity Important?

It’s about the safety of people, our equipment and our business

This is what we want to avoid!Why is Well Integrity Important?

It can help to prevent incidents like this

Integrity Drivers & Implementation

• Safety • Statutory regulations • Internal Policy &

Standards • Production • Reputation

• Technical & Performance Standards

• Procedures • Industry Standards • Vendors Procedures • Knowledge , Training

& Competency

Well Integrity Minimum Standards Standard / Element No What , Where & How ?

1) Accountable Person Wells Technical Authority

2) Well Operating Procedures Well Handover Process & Operate Wells

3) Well Intervention Procedures Field Specific Procedures

4) Tubing / Casing Integrity Management Field Specific Procedures

5) Xmas Tree Maintenance & Testing Policy

Field Specific Procedures & Planned maintenance routines (PMR’s)

6) DHSV / ASV Integrity Management Field Specific Procedures & Planned maintenance routines (PMR’s

7) Knowledge Management Drilling & Well Operations Policy

Well Construction Principles • Generally a well will consist of conductor, casing,

tubing, wellhead and Christmas tree.• The conductor protects the casing from seabed to

platform surface, and provides a stable support for the wellhead and Christmas tree.

• Three or four strings of casing will be run inside the conductor, with diminishing I.D’s

• Typically 30” conductor.• 20” Surface Casing • 13.3/8” Intermediate Casing• 9.5/8” Production Casing • 7” Liner

Casing Design : Basic Construction

12

3

67

9

11

10

1. 30” conductor

2. Conductor setting depth

3. 20” surface casing

4. 20” shoe

5. Cement

6. Formation open to C annulus

7. 13 3/8” casing

8. Formation open to B annulus

9. 9 5/8” production casing

10. Liner hanger

11. 7” Liner

12. TD – Total Depth

12

4

5

8

Completion Components – What’s installed

1

2

4

7

9 10

1112

6

1. Tubing hanger (Upper annulus barrier)2. SC-SSSV (Sub-surface barrier)3. Control line4. Tubing (Vertical barrier)5. A annulus (tubing-casing)6. Gas lift valves (in SPMs)7. Expansion joint: Tubing Seal Receptacle8. Anchor seal assembly9. Production packer10. Packer sealing element (Lower barrier)11. Tailpipe12. WEG

5

3

9 5/8”Production

Casing

8

Completion Components – Why?

Function : 1

2

4

7

9 10

1112

6

1. Upper annulus barrier & supports tubing2. Protects the surface installation 3. Hydraulically operates the SC-SSSV4. Conveys hydrocarbons to surface5. Protects production casing from attack6. Permit entry of lift gas annulus to tubing7. Accommodates expansion / contraction8. Ties & seals tubing string to packer9. Anchors tubing string to production csg10. Forms lower barrier of the A annulus11. Allows installation of instrumentation12. Easy entry of production logging tools

back into tailpipe

5

3

9 5/8”Production

Casing

8

Annular Safety Valve - Gas Lift

The ASV contains large amounts of pressurised gas in the tubing-casing annulus – should the well-head become damaged

An 8,500 ft annulus contains large quantities of lift gas when pressured up to 1800 psi

Provides annular by-pass via a hydraulically operated valve array

Lift Gas

Annular Safety Valve - Closed

Lift gas above ASV escaped to surface following loss of surface systems integrity

Evacuated Lift GasASV in Closed Position

Lift gas retained in A annulus below ASV

Integrity DriversIntegrity Drivers

The Well Integrity Envelope

DHSVs - Regular integrity & function testing

Xmas Trees - Regular Maintenance and Testing

Annuli – Regular monitoring & reporting

Report and Action if set criteria do not meet expectations.

Why monitor annuli pressures ?

• The annular voids form the principal barriers between the produced fluids and the atmosphere.

• By monitoring the annulus pressures we are able to assess the condition and integrity of the well tubulars.

• Anomalous annulus pressures may give the first indication of down hole problems although it does not automatically mean there is a leak

• Thermal expansion or ingress of formation fluid could also cause an increase in annulus pressure, regular sampling of annulus fluids may also be undertaken

• Annulus temperatures should also be considered

Definition :

“the area between two concentric circles” “a ring shaped part , figure or space”

Annulus Monitoring - Well Start-up

Tbg A B C Formn

Increasing distance from tubing

Depth

Tubing, Annulus & Formation Temperature

Hot Cool

ABCABC

Formation

Cuttings Re-Injection

Recommended Annuli Naming Convention

Example of Collapsed Tubing