CO2 Diversion With Foam in an Immiscible CO2 Field Project

Summary A foam emplacement technique was applied through one well in the tar zone of Fault Block V in the Wilmington field to improve the distribution and sweep efficiency of injected CO2. The Long Beach Oil Development Co. is conducting an immiscible CO2/N2 water-alternating-gas (WAG) flood in this waterflooded, heavy-oil reservoir. Laboratory studies showed reduction in CO2/N2 gas mobility and improvement in overall sweep of laboratory cores by the addition of Alipal CD-128 foaming agent during the gasflood. The field application of the foaming technique was successful in diverting the gas to a previously unswept interval, but subsequent injection of water diluted the foam to the extent that it lost its effectiveness.