致密储层表面活性剂带压渗吸效果主控性能研究

Study on the oil displacement performances and main controlling property of surfactant forced spontaneous imbibition in tight reservoir

为明确表面活性剂在致密储层带压自发渗吸驱油的主控性能,分析不同驱油机理对渗吸效率的作用方式,以定边长8致密油藏为研究对象,选择4种性能差异明显的表面活性剂体系开展带压渗吸实验。结果表明,油水乳化性能越强,乳液粒径越小,有利于使油滴运移转变为扩散方式;润湿性的改善有利于提高细小孔喉的吸水过程,适当降低界面张力有利于发挥毛管力的驱动作用与排油过程。致密储层表面活性剂带压渗吸的主控性能依次为乳化性能>润湿性>界面张力。

In order to clarify the main controlling property of surfactants in tight reservoir by forced spontaneous imbibition,and analyze the contribution of different oil displacement mechanisms to imbibition efficiency,taking Dingbian Chang8 tight reservoir as the research object,four surfactant systems with obvious differences in performance were selected to carry out pressure imbibition experiments.The results show that the stronger the oil-water emulsification property is,the smaller the particle size of the emulsion is,which is conducive to the transformation of oil droplet migration into diffusion.The improvement of wettability is beneficial to improve the water absorption process of micro-nano pores,and the appropriate reduction of interfacial tension is beneficial to capillary force drive and oil drainage.The main control property of surfactant in forced imbibition of tight reservoir is emulsification>wettability>interfacial tension.