Immiscible WAG injection was successfully used to enhance the oil recovery in the thick, heterogeneous reservoir in the east of Beier area of Daqing oil field. After a five year test period, the water cut is basically stable and production is continuously increasing. The recovery factor is now more than 3% higher than the ultimate recovery factor by water injection, and ultimate recovery is predicted to be more than 8% higher. Changes have taken place in the water entry profile of the injection well. Gravity segregation occurs in the reservoir. Areal sweep conditions are improved and the thickness of liquid production increased.

Keywords:
enhanced recovery, Daqing Oil Field, positive rhythm sedimentation, Upstream Oil & Gas, gas injection, waterflooding, heterogeneous thick reservoir, miscible method, Pilot Test
Subjects:
Improved and Enhanced Recovery, Miscible methods, Waterflooding
Copyright 1997, Society of Petroleum Engineers
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