电化学导流驱油提高低渗透油藏采收率机理研究

A Study on the Mechanism of Electrochemistry Oil Displacement Field Improving the Recovery Factor of Low-Permeability Reservoirs

通过大量室内试验 ,详细分析研究了外加直流电场作用下对油水两相渗流规律及储层岩石性质的影响 .研究结果表明 :在外加电场作用下 ,使水驱油采收率、油相相对渗透率提高 ,水相相对渗透率、含水率减小 ;同时外加直流电场可以改变储层岩石的孔隙结构和粘土矿物的结构、性质 ,并使储层岩石润湿性向亲水方向转化 ;影响这些变化的主要因素包括电位梯度、驱替流体矿化度、电场作用时期等 .

The effects of external direct electric field on the seepage characteristics of oil and water phases and rock property were studied by means of a great many of laboratory tests. The test results show that the recovery factor of crude oil and the relative permeability of oil phase are increased, and the relative permeability of water phase and water cut are decreased. The parameters are mainly influenced by potential gradient, electric field affecting period and the salinity of displacement fluid. The direct electric field can change the pore structure of rock, and the structure and property of clay mineral. It can also make cores become more hydrophilic. Therefore, it is held that the direct electric field can improve the development result of low permeability, high water cut and depletive reservoirs. But it has little effect on matrix mineral of rock.