Well Integrity Overview

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Well Integrity Overview
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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? Its about the
safety of people, our equipment and our business
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This is what we want to avoid!
Why is Well Integrity Important?
It can help to prevent incidents like this
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Integrity Drivers Implementation

• Safety
• Statutory regulations
• Internal Policy Standards
• Production
• Reputation

• Technical Performance Standards
• Procedures
• Industry Standards
• Vendors Procedures
• Knowledge , Training Competency

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Well Integrity Minimum Standards
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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.Ds
• Typically 30 conductor.
• 20 Surface Casing
• 13.3/8 Intermediate Casing
• 9.5/8 Production Casing
• 7 Liner

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Casing Design Basic Construction

• 30 conductor
• Conductor setting depth
• 20 surface casing
• 20 shoe
• Cement
• Formation open to C annulus
• 13 3/8 casing
• Formation open to B annulus
• 9 5/8 production casing
• Liner hanger
• 7 Liner
• TD Total Depth

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Completion Components Whats installed

• Tubing hanger (Upper annulus barrier)
• SC-SSSV (Sub-surface barrier)
• Control line
• Tubing (Vertical barrier)
• A annulus (tubing-casing)
• Gas lift valves (in SPMs)
• Expansion joint Tubing Seal Receptacle
• Anchor seal assembly
• Production packer
• Packer sealing element (Lower barrier)
• Tailpipe
• WEG

9 5/8 Production Casing
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Completion Components Why?
Function

• Upper annulus barrier supports tubing
• Protects the surface installation
• Hydraulically operates the SC-SSSV
• Conveys hydrocarbons to surface
• Protects production casing from attack
• Permit entry of lift gas annulus to tubing
• Accommodates expansion / contraction
• Ties seals tubing string to packer
• Anchors tubing string to production csg
• Forms lower barrier of the A annulus
• Allows installation of instrumentation
• Easy entry of production logging tools back into
  tailpipe

9 5/8 Production Casing
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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
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Annular Safety Valve - Closed
ASV in Closed Position
Evacuated Lift Gas

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

• Lift gas retained in A annulus below ASV

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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.
Integrity Drivers
Integrity Drivers
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Why monitor annuli pressures ?
Definition the area between two concentric
circles a ring shaped part , figure or space

• 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

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Annulus Monitoring - Well Start-up
C
A
B
A
B
C
Tbg A B C Formn
Depth
Formation
Increasing distance from tubing
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Cuttings Re-Injection
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Recommended Annuli Naming Convention
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Example of Collapsed Tubing