Flooding by High-Concentration Polymer Doubled Oil Recovery of Common Polymer on Field Test with 20% Closed to the Result of Laboratory Test in Daqing

Abstract

Abstract Common polymer flooding on-site tests and industrialized application indicates that conventional polymer flooding gives about a 10% more oil recovery than waterflood, with an ultimate recovery of 51% OOIP. But, because the existence of high permeable zones, this sometimes makes polymer flooding insufficient or ineffective in the reservoir. In some polymer flooding producers, after polymer is breakthrough, water-cut increases rapidly, it adversely affects polymer flooding, resulting in on-site enhancing recovery greatly lower than 20% of laboratory estimates. In 2002, on the basis of high concentration polymerflooding study in lab, we perform high concentration polymer flooding on-site. By optimizing slug combination and adequate monitoring and analyses, water-cut is greatly decreased, with a decrease percentage of 14.5, this improves polymer flooding development effect. The field test data shows, that high concentration polymer flooding in beginning, recovery has given 4.2% higher than that of conventional polymer flooding by Dec. 2005; and flooded in later stage recovers 3% more oil than conventional method, this indicate that the result of high concentration polymer flooding in initial stages is better than in later stage. Polymer flooding monitoring and simulation technology predicts that 19.8% more oil can be recovered than water flooding, with a production degree of 61% OOIP. On-site high concentration polymer flooding recovery is two times of the conventional polymer.