Fine Injection-Production Adjustment Study on Binary Flooding for Changqing Low Permeability Reservoirs

Abstract

Jurassic reservoirs in Ordos Basin are typical low permeability reservoirs, most of them have entered high water cut and high recovery percent stage, therefore it is difficult for conventional measures to increase oil recovery. The polymer surface binary flooding technology can effectively improve the ultimate recovery rate of this kind of reservoir. Based on the well microstructure, reservoir status, remaining oil distribution and dynamic data analysis in the test area, this paper summarizes the fine injection-production adjustment technology of binary flooding suitable for low permeability reservoir. It is concluded that the key factors to improve oil recovery in low permeability reservoirs are the continuous injection system, the unblocked near-well-bore zone, the reasonable pressure maintenance level and the relative homogeneity of reservoirs. After the implementation of binary flooding in Changqing Jurassic reservoir, the resistance of underground fluid seepage increased, and the formation of some oil Wells was blocked, and the liquid production of oil wells cannot be recovered. Therefore, it is necessary to cooperate with the stimulation measures and injection-production adjustment to increase the liquid production. In order to effectively improve oil recovery in low permeability reservoirs, the polymer surface binary system must be combined with fine injection-production adjustment technology. According to these study results, differentiated production well adjustments had been carried out, and the field test results were significant.