清洁压裂液破胶液渗吸过程中油水两相的运移规律

Oil-water Two-phase Migration in Imbibition Process of Gel Breaking Fluid of Clean Fracturing Fluid

戴彩丽 李 源 徐效平 赵明伟 袁 斌 徐 克 高明伟 吴一宁

DAI Caili LI Yuan XU Xiaoping ZHAO Mingwei YUAN Bin XU Ke GAO Mingwei WU Yining

目前针对清洁压裂液破胶液渗吸机制的研究主要聚焦于岩心宏观润湿性、油水界面张力及岩心尺度采收率，缺乏对于渗吸过程微纳米孔隙中油水两相运移规律直观而有效的认识。以清洁压裂液破胶液为实验流体，利用2.5维高仿真微观孔喉阵列模型，模拟清洁压裂液破胶液在毛管力渗吸作用下的油水两相动态分布规律。结果表明，清洁压裂液渗吸过程中润湿相毛管力（驱动力）与界面扩张、贾敏效应及黏性力损耗（阻力）存在多次动态平衡过程，油水两相运移形成“吸水-排油-吸水”交替的分阶段过程。当油相动用效率分别达到10.98%、19.09%与37.27%时，吸水与排油交替进行，产生类似“憋压”的效果。微纳米孔隙中油水两相运移规律对认识清洁压裂液的渗吸作用机制具有重要参考意义。

Research on the imbibition mechanism of gel breaking fluid of clean fracturing fluid mainly focuses on macro core wettability，oil-water interfacial tension and core-scale recovery，lacking intuitive and effective understanding of oil-water two-phase migration behavior in micro/nano pores during imbibition. In this paper，the gel breaking fluid of clean fracturing fluid was used as experimental fluid，and the dynamic distribution of oil-water two-phase under capillary force imbibition was simulated by using 2.5-dimensional pore-throat microchannel. The experimental results showed that there were continuously dynamic equilibrium processes between capillary force（driving force）of wetting phase and interfacial expansion，Jamin effect and viscous force loss（resisting force）in the imbibition process of clean fracturing fluid. The oil-water two-phase migration formed an alternate stage process of“water absorption，oil drainage and water absorption”. When the oil production efficiency reached 10.98% ， 19.09% and 37.27%，water absorption and oil drainage alternated to produce oil. It was a similar effect of“suppressing pressure”. The oil-water two-phase migration behavior in micro/nano pores was a great significance for understanding the imbibition mechanism of clean fracturing fluid.