Transcript Integrity for Offshore Operators

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
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8
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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
Completion Components – What’s
installed
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9 5/8”
Production
Casing
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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
Completion Components – Why?
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9 5/8”
Production
Casing
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Function :
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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
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
ASV in Closed Position
 Lift gas above ASV escaped
to surface following loss of
surface systems integrity
 Lift gas retained in A annulus below
ASV
Evacuated Lift Gas
The Well Integrity Envelope
DHSVs - Regular integrity & function testing
Xmas Trees - Regular Maintenance and Testing
Integrity Drivers
Annuli – Regular monitoring & reporting
Report and Action if set criteria do not meet expectations.
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
Annulus Monitoring - Well Start-up
C BA
ABC
Tbg
A
B
C
Formn
Depth
Formation
Increasing distance from tubing
Tubing, Annulus & Formation Temperature
Hot
Cool
Cuttings Re-Injection
Recommended Annuli Naming
Convention
Example of Collapsed Tubing