低渗透油藏自发渗吸驱油实验研究

通过低渗透亲水岩心自发渗吸实验,探讨了低渗透油藏不同界面张力体系的渗吸驱油过程。研究结果表明,注入水渗吸体系因毛细管力较高、毛细管力与重力比值较大,其渗吸过程为毛细管力支配下的逆向渗吸。与注入水渗吸结果相比,化学剂溶液因降低油水界面张力,在孔隙介质中能使更多的原油参与渗流过程,使更多的剩余油变为可动油,提高了渗吸平衡时的原油采出程度,因而提高了低渗透油藏原油的采收率。

Experimental study of spontaneous imbibition in low-permeability reservoir

The spontaneous imbibition process of solution with different interfacial tension in low permeability reservoir was investigated experimentally by low permeability (about 0.004μm²) water wet oil saturated sandstone cores.The result showed that the fluid flow for the water wet system is countercurrent at high capillary force. Especially in the presence of brine and high interfacial tension, the imbibition process was entirely governed by capillary force.The evaluation of the positive changes in recovery rate and ultimate recovery compared to the brine imbibition showed that the low interfacial tension made the residual oil more easily to flow and enhanced oil recovery of surfactant imbibition in low permeability reservoirs.