Success Story of Well Interventions Identified via Surveillance Maps

Abstract

Surveillance mapping is a reservoir management process first developed by Shell and Exxon for the Brent field in the UK North Sea. It involves an integrated reservoir-wide management process with the objective of not only understanding subsurface dynamics during production but also delivering a future work programme that will maximize reservoir potential.1 Surveillance Mapping was recently deployed in candidate selection for Short Term Oil Generation and Work Over activities in the Zoom reservoir located in the Niger Delta area. The Zoom reservoir is an East West Trending anticlinal structure, predominantly shore face deposits with incised channels. The Zoom reservoir, which is a large structure, commenced production in August 1991 and 50MMstb of oil has been produced to date. Thirteen oil wells have produced from the Zoom reservoir. These wells were drilled in phases post updates of various development plans published in 2003 and 2010. Production performance across the reservoir started declining due to natural water encroachment, poor productivity issues, well and flow line sabotage etc. This triggered an aggressive strategy to identify suitable remedial action that would support the drive for resuscitating the wells in a cheap and safe manner. Five wells were identified as potential Short-Term Oil Generation candidates and have been executed successfully with good rewards. This paper will review the success story of candidate wells scoped from the surveillance map and its impact on the optimization of the reservoir potential.