润湿性对低渗致密储层自发渗吸的影响

Effect of wettability on spontaneous infiltration absorption efficiency of low permeability tight reservoir

低渗致密储层内的原油很难通过自发渗吸而采出,该类储层中的原油的渗吸效率主要取决于基质的润湿性能。利用表面活性剂改变低渗致密储层岩石的润湿性,并进行渗吸实验,评价不同种类表面活性剂的润湿性能和渗吸能力,研究润湿性对低渗致密储层自发渗吸的影响,认为低渗致密储层亲水性岩石自发渗吸后润湿角会增大,润湿角在50°～70°,即近弱水湿偏中性润湿时会有更高的渗吸效率,建议对低渗致密储层岩心使用阴-非离子表面活性剂将岩心润湿性调整到近弱水湿偏中性润湿,能够取得更高的渗吸效率。有助于针对储层条件找到合适的表面活性剂,有针对性地调整低渗致密储层岩石的润湿性,从而可以达到提高原油采收率的目的。

Crude oil in low permeability tight reservoir is difficult to be extracted by spontaneous infiltration absorption.The permeability of crude oil in this kind of reservoir depends mainly on the wettability of the matrix.Using suffactant to change the wettability of low permeability reservoir, and carrying out permeability test,estimating different kinds of suffactant in the evaluation of wettability and permeability absorption ability.Research on the effect of wettability on spontaneous infiltration absorption efficiency of low permeability tight reservoir.According to the survey,the wetting angle of hydrophilic rock in low permeability tight reservoir will increase after spontaneous infiltration absorption,the wetting angle between 50° -70° near weak water wettability to neutral wettability, which will have higher infiltration efficiency.It is pointed in this paper that using Yin-nonionic suffactant for low permeability reservoir cores to adjust core wettability to near weak water wettability to neutral wettability, which can achieve higher spontaneous infiltration absorption efficiency.It is helpful to find suitable surfactant for the reservoir conditions to adjust the wettability of the low permeability and tight reservoir rocks.