Jilin Oilfield Polymer/surfactant Binary System Adaptability Evaluation

The feasibility of using polymer/surfactant binary system to enhance oil recovery ofHonggang block was studied aiming at the current situation of Jilin oilfield, such as strongheterogeneity, high moisture content, scattered distribution of residual and so on. Then the oilrecovery of Jilin oilfield could be enhanced on the basis of the theory data of this work.The influences of polymer molecular weight, polymer concentration, surfactantconcentration and salinity on the viscosity, interfacial properties, emulsifying properties ofbinary system were systematically determined in this work, and the influences on the size ofhydration molecules were studied by the micropore filter assay, too. The optimum formulawas finally determined basing on the reservoir pore throat characteristics, the compatibility ofpolymer and reservoir pore throat, and the oil displace experiments.Based on the above conclusions, the optimum composite of binary system was given.The results showed that under the conditions that the molecular weight of the polymer is2×10⁷, the polymer concentration is1500-2000mg/L, the surfactant concentration is0.2%-0.3%of the binary system, then the interfacial tension of oil and binary system wasultralow(10^-3mN/m). The emulsification, inject ability and compatibility were good. Thewater injection profile could be controlled, and the binary system had better adaptability tothe formation conditions of Jilin oilfield.