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SPE Annual Technical Conference and Exhibition,
21-24 September 2008,
Denver, Colorado, USA
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Abstract
This paper describes a process for actively managing well integrity throughout
the development life cycle with a particular focus on the production operations
/ well maintenance phase. Although developed in relation to ConocoPhillips UK
North Sea development wells, most of the features of the process have
application to all development well operations (both onshore & offshore)
under any regulatory regime.
The original well integrity management process was developed in order to
demonstrate compliance with the UK Offshore Installations & Wells (Design
& Construction, etc) Regulations 1996 (DCR). Since that time the original
process has continued to be modified to improve effectiveness & efficiency.
As well as describing the current process, this paper also describes its
development and how we see that the process might evolve in the future.
DCR regulations form a part of the UK ‘safety case’ regime. The ‘safety case’
regime places a strong focus on the development of site-specific performance
standards; it also utilises the principles of independent examination &
verification in order to demonstrate compliance. The process described in this
paper represents a significant new contribution to the management of major
accident hazards in well operations since it focuses on the use of performance
standards and independent examination in order to ensure well integrity.
Introduction
All prudent well operators recognise the need to actively manage well integrity
throughout the development life cycle. Different operators take different
approaches depending on the nature of their operations, the risk profiles
presented and the regulatory regime.
It is arguable that the industry has historically focussed a great deal of its
attention on management of well integrity during the well design and
construction phase. For exploration and appraisal wells drilled in increasingly
challenging environments (underbalanced, HPHT, etc) this is entirely
appropriate. However, it may be that in doing so the industry has not kept pace
in terms of managing its approach to development well integrity during the
operations and maintenance cycle. For many development wells, continued
application of tried and tested industry standards is probably still the best
strategy. However, in other situations, a fresh approach may be
justifiable:
• For subsea development wells,
often remote from host facilities, well integrity management standards might be
improved by reflecting site-specific safety & environmental risks rather
than applying integrity management standards more appropriate to platform-based
wells.
• Even for conventional
platform / onshore wells, appropriate integrity management standards might be
allowed to vary depending upon well conditions (e.g. not-naturally-flowing,
etc).
• Recent developments in
completion equipment (particularly subsurface safety systems) may also justify
changes to historically accepted well integrity management standards.
• Historically, well
intervention operations have often received less formal control than drilling
operations. There is perhaps a need to recognise that some of these operations
pose potentially increased safety risks and should be subject to a greater
level of control through the application of appropriate operations
standards.
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