Assuring the Mechanical Integrity of Expandable Sand Screens
Stephen Willson (BP America Inc.), Tony Crook & Jian Guo Yu (Rockfield
Software Ltd.); Jørn Stenebråten (TerraTek Inc.); John Gilchrist
(BP Amoco Exploration Ltd.) & David Tiffin (BP America Inc.)
This paper was presented at the 2002 Offshore Technology Conference held in Houston, Texas U.S.A., 6-9 May 2002,
Copyright 2002, Offshore Technology Conference.
Abstract
Expandable sand screens have the potential to revolutionize sand control
in weak reservoirs. However, by they very fact that plastic expansion
of the screen is necessary to deploy it, concerns have been raised
as to how these completions will perform if run in very deformable
reservoirs.
This paper presents the results of an extensive mechanical characterization
testing and analysis program designed to assure the mechanical integrity
of expandable screens when deployed in weak, compacting reservoirs undergoing
significant reservoir depletion. The expanded screens are inherently
weak when tested using conventional crush testing. However, traditional
crush testing does not correctly simulate the loading imparted onto the
screens under actual reservoir conditions. To address these concerns
the results of an extensive laboratory crush and buckling tests performed
on sections of expanded screens are reported. The tests are designed
to mimic potential failure modes when screens are deployed in both vertical
and horizontal wells. The laboratory results have then been analyzed
in detail using advanced numerical finite element modeling techniques.
Important features of the numerical modeling are described; importantly,
the paper discusses the relative merits of 2-dimensional versus 3-dimensional
finite element representations of the screens, and the extent to which
unequal slot opening and initial imperfections influence the collapse
resistance.
Numerical simulations of ESS screen performance in compacting reservoirs
are then presented and discussed.
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