Development And Evaluation Of High Temperature Polymer Profile Control Agent

Water flooding method is generally adopted in oil plants across our country. In the oil production tail, water content increases rapidly and geologic parameter is getting complicated. Most injection grout penetrates along the high permeability zone, which will cause the chemicals circle invalid and limit the mount of oil extracted from reservoirs. Therefore, profile control is required in the water plugged wells.In this report, the synthetic principle of polyacrylamide- phenolic resin gel was studied. The resin gel formation time and strength was shown affected by the contents of the essential constituents including phenol, cross-linker and correctives. The optimized compound design was obtained through the experimental analysis as: 1.1% PAM+1.1% phenol +1.3% cross-linker+0.5% correctives.Indoor experiments showed that high temperature polymer blocking agents remained the volume occupation of more than 90% after 10 days under environmental temperature of 130°C. Synthetic time of the high temperature polymer blocking agent is controllable in the time range from 22h to 36h. The strength was obtained as 12000 mPa·s. The viscosity of the blocking agent was reduced by 15% after shearing, which presents excellent shear strength. The minimum cross-linking time was obtained when pH=2, which inspired us to use acid materials as catalyser. The strength and formation time of the gel were also tested by adding Nacl, Cacl₂, and Mgcl₂ into the solution. Results showed that the amount of influence by adding these salts was ranking as Nacl< Cacl₂ 2.Results from Core Laboratory showed that the blocking agents has a plugging ratio more than 98% for different rock cores, average breakthrough pressure was 2MPa. The plugging ratio was still more than 92% after scour experiment. Parallel core simulating experiment showed that the gel formed in the core redirected the injected flow and expanded the sweep area.