Well Integrity Within Norsk
Well Integrity Within Norsk
Well Integrity Within Norsk
INTERNAL
Objective
ACV PMV P
SCV
PWV PCV
Methanol
Wellmaster database
Update of operational procedures
Retrievabl
e isolation
packer
Sliding sleeve Flow control valves
Procedure is finished
Remains:
Implementation
20.0 %
15.0 %
10.0 %
5.0 %
0.0 %
1995 1996 1997 1998 1999 2000 2001 2002 2003 2004
Note: Based on Norsk Hydro WellMaster phase V data (Snorre and Visund currently
Statoil), last major database update April 2004
INTERNAL • Date: 2005-01-13 • Page: 5
Task Force : Well leaks - Root Cause Analysis
Inge M. Carlsen
Sintef
J. Abdollahi
Sintef
Tommy Langnes Geir Ove Haugen Hilde B. Haga Tore R Andersen Thorvald Jakbsen
OCTG Drill pipe Completion design Material technology Prod. technology
Reference group : Bjørn Engedal (leader), Nils Romslo, Geir Slora, Eli Tenold, Bjarne Syrstad, Torbjørn Øvrebø, Siamos Anastasios
Purpose:
A uniform and structured approach for handling of well integrity during
the lifetime of a well.
All information available through one system
A clear indication of the well barrier status at all times
INTERNAL
Rationale for risk based approach
Main results
Extensive diagnosis part Acceptance Risk and response
criteria evaluation
Risk assessment method
– Specific risk acceptance criteria
– Extensive use of quantitative risk Implementation and
analysis (fault tree analysis with follow-up
WellMaster data as input)
– Specific risk reduction measures
Documentation of process
Criteria RSC
Well barrier leak rate lower than acceptance criterion (not B
considered a failed barrier)
Criteria RSC
The hydrocarbon storage mass in the well annuli is, or may C
become, greater than the acceptance criterion
OR
Well annuli fluids are highly toxic (platform well)
Otherwise B
Criteria RSC
Material corrosion or erosion is the (most likely) leak cause. D
There is, or is a potential for, exposure of equipment to C
H2S/CO2 levels that are outside design/NACE specifications.
OR
There is crossflow (unintended flow) in the well
Otherwise B
Criteria RSC
The maximum potential A-annulus pressure - PA (MTP / A- C
annulus injection pressure) is greater than MOASP
OR
Mechanical / Pressure loads causing burst/fracture/collapse is
the (likely) leak cause
Otherwise B
Criteria RSC
An additional single well barrier leak situation may affect the C
ability to efficiently kill the well with mud.
Otherwise B
The resulting Well RSC determines a set of mandatory (M) and alternative
(S) remedial actions/risk reducing measures to be implemented
Remedial actions for each RSC based on
Norsk Hydro and industry best practice
The risk assessment (step 1 through 6)