Print this pageNew Advances in Enhanced Oil Recovery for Mature Oil Fields - Successful Polymeric Surfactant Chemical EOR Laboratory and Field Demonstration
There has been an increased interest in the application of chemical EOR (Enhanced Oil Recovery) methods with the rapid escalation in oil prices since 1999. This presentation describes the development and application of a new type of chemical EOR based on polymeric surfactant chemistry. The advantages of this new chemistry are discussed, as well as favorable laboratory results, and finally, its successful field application.
One conventional chemical EOR process is to inject only a polymer solution. This increases the viscosity of the injection water and thereby improves the sweep efficiency over that of waterflood . As compared to this case, the polymeric surfactant has the advantage of mobilizing additional oil because of its reduction in the IFT. Another established technology for chemical EOR involves a mixture of surfactant and polymer products. Polymeric surfactant as a single product can have an inherent cost advantage over using two separate chemical products. There is also a technical advantage; this polymeric surfactant will maintain its constant chemical behavior in the reservoir. Injecting a blend of individual polymer and surfactant products will suffer from chemical separation in-situ and so have a decrease in effectiveness.
Polymeric surfactant candidate product were developed and screened in laboratory measurements that confirm that they can be created with substantial molecular weight (even to multiple millions) that provide solution viscosity similar to that of conventional EOR polymers. In addition, the same polymeric surfactants can create IFT values one or more orders- of-magnitude lower than the IFT for different crude oils and field brines. Laboratory core flood tests demonstrated recovery of the original oil in place is several percent greater when injecting polymeric surfactant versus a conventional polymer solution. The most promising polymeric surfactant products have had successful field demonstration in Daqing Field.
AAPG Search and Discovery Article #90090©2009 AAPG Annual Convention and Exhibition, Denver, Colorado, June 7-10, 2009