Based on the success of the Cruse ‘E’ Pilot steamflood, Petrotrin decided to venture into a large-scale project of a similar nature called the Cruse ‘E’ (IADB) Expansion Steamflood. The project area consisted of 270 acres, with an estimated original oil in place of 31.1 million barrels in the zone of interest, the Upper Cruse ‘E’ sand. Surface and infrastructure work began in January 1994, which was followed by rig work - drilling, recompletions, and workovers. Sixty (60) new wells comprising twnty-eight (28) injectors and thirty-two (32) offtakes were drilled and completed to form twenty-eight (28) patterns. Also thirty-five (35) existing wells were utilized as offtakes. The project was commissioned in January 1996 when steam injection began. This brought the number of active steamfloods and WASP projects at Petrotrin to eight (8). It was predicted by reservoir simulation that 11 million barrels of heavy oil would be recovered over fifteen (15) years with production peaking in the year 2000.

However, in 1998 when oil production reached 877 bopd, the project was adversely affected by environmental concerns to a residential area in the vicinity of the steamflood and it was actually shutdown by order of the regulatory body in November 1998. Extensive environmental work was undertaken in the areas of communication, training and operations to improve the safety and environmental aspects of the steamflood, and ensure that it was brought up to the environmental standards required. After forty (40) months of inactivity, approval was finally obtained in March 2002 from the regulatory body to restart steam injection.

This paper discusses the performance of the steamflood during steam injection and during no injection, the technical, operational and economic aspects of the project, and the environmental upgrade conducted.. The paper also discusses the restarting exercise conducted for steam injection and presents future operating strategies.

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