Water Injection completion selection in a deepwater subsea environment requiring sand control is currently an inexact science with lack of a proven track record for life of field solutions. The West of Shetlands (WoS) fields Foinaven, Schiehallion and Loyal have been on injection since 1997 and are starting to develop a substantial track record of injection performance. This case study will provide a performance comparison of the 2 main completion types installed to date, namely Cased and Perforated (C&P) and standalone Wire Wrap Screens (WWS), along with a subset of a three zone Smart well completed with premium sand screens. The comparison focuses on 4 main areas;

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    Well Longevity

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    Completion Efficiency (skin)

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    Injection Conformance (Near Wellbore)

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    Performance of single and multi-zone injectors

The WWS screen performance is further subdivided by clean-up technique of which there are currently 5;

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    Backflow Oil Based Mud (OBM)

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    Bullhead Oil Based Mud

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    Bullhead Water Based Mud after spotting Breaker

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    Toe Fracture using External Casing Packer

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    Displace OBM to Solids Free OBM and bullhead

A variety of data will be presented as part of the comparison including, PLT Data, MDT Data, PFO Results, Hall Plots, UCS Data. A simple set of criteria is presented to select when C&P or sand screens are viable completion solutions.

Keywords:
well 204, injector, injection, schiehallion, underbalance, completion efficiency, hall plot, shetland, completion installation and operations, enhanced recovery
Subjects:
Drilling Fluids and Materials, Reservoir Fluid Dynamics, Improved and Enhanced Recovery, Formation Evaluation & Management, Professionalism, Training, and Education, Drilling fluid management & disposal, Perforating, Screen selection, Flow in porous media, Waterflooding
Copyright 2004, Society of Petroleum Engineers
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