压力和电场对低渗油藏基质中采收率的影响

EFFECT OF PRESSURE AND ELECTRIC FIELD ON RECOVERY FACTOR OF MATRIX IN LOW-PERMEABILITY RESEROVIR

大多数低渗透油藏是由致密基质和裂缝构成的双重介质。基质与裂缝内流体之间的渗吸效应是低渗透基质油藏开采的一种重要机理。在应用BuckleyLeverett 方程改进了渗吸数学模型的基础上，从常规实验的角度，分别进行了不同压力和电场环境下的渗吸实验。结果表明，由于压力传播的延迟性，压力变化导致渗吸过程发生变化；直流弱电场对渗吸有一定的抑制作用，强电场对渗吸有一定的促进作用。结合推导出的渗吸数学模型，较好地解释了压力和电场对渗吸效应的影响，初步得出了物理场参数对渗吸效应的影响规律。

Most low-permeability reservoirs are double media composed of tight matrix and fractures. Imbibition effect between fluids in matrix and fracture is a significant mechanism for low-permeability matrix reservoir produc- tion. Based on imbibition mathematical model improved by using Buck＇ley-Leverett equation and through conven- tional experiments, imbibition experiments are carried out under various pressure and electric environment. Results show that due to pressure transmit delay, pressure variety results in imbibition process variety, direct current and weak electric field constrains imbibition effect and strong electric field improves imbibition. Effect of pressure and electric field on imbibiton effect is better interpreted associated with deduced imbibition mathematical model and effect rules of physical field parameters on imbibition effect are preliminarily determined.