致密储层体积改造润湿反转提高采收率的研究

发布时间：2018-06-20 23:02

本文选题：油田开发 + 致密储层　；参考：《深圳大学学报(理工版)》2017年01期

【摘要】：以致密油气体积改造注入的压裂液为切入口,将表面活性剂复配至压裂液中,探索在压裂过程中改变储层基质润湿性,提高采收率的方法.基于接触角和界面张力测量,在压裂液中分别添加阳离子表面活性剂、阴离子表面活性剂和非离子表面活性剂,在不同润湿状态下对致密岩心进行渗吸物模实验.通过改变润湿反转前后的相渗曲线和毛管压力曲线,对该过程进行模拟研究.结果显示:仅依靠压裂液不能引起润湿反转,渗吸采收率仅为4.95%.添加表面活性剂后润湿性发生变化,渗吸采收率有大幅提高,其中阳离子表面活性剂改变润湿性的能力要好于非离子表面活性剂和阴离子表面活性剂;考虑润湿反转的模型可对表面活性剂润湿反转过程进行较好描述,模拟结果与实验数据拟合较好;现场一平台井压裂液中加入润湿反转剂DL-15后,体积压裂形成复杂裂缝,产量比邻井提高2~4 t/d.建议体积改造形成复杂缝网的前提下,在压裂液中添加表面活性剂,延长焖井时间,依靠停泵后的压差驱替和渗吸置换作用,提高开井后产量.
[Abstract]:Taking the fracturing fluid injected by the compact oil and gas volume transformation as the entry point, the surfactant was mixed into the fracturing fluid to explore the method of changing the wettability of reservoir matrix and improving the oil recovery during fracturing. Based on the measurement of contact angle and interfacial tension, cationic surfactants, anionic surfactants and Nonionic surfactants were added to the fracturing fluid. The process was simulated by changing the phase permeability curve and capillary pressure curve before and after wetting inversion. The results show that the wetting reversal can not be caused by fracturing fluid alone, and the permeability recovery is only 4.95%. The wettability changes with the addition of surfactants, and the permeability recovery is greatly improved. The ability of cationic surfactants to change wettability is better than that of Nonionic surfactants and anionic surfactants. The model considering wetting inversion can describe the wetting inversion process of surfactants, and the simulation results fit well with the experimental data. After adding wetting inversion agent DL-15 into the fracturing fluid of a platform well in the field, the complex fracture can be formed by volume fracturing. The output is increased by 2 t / d to 2 t / d. It is suggested that adding surfactant to fracturing fluid and prolonging well braising time should be carried out on the premise of volume modification to form complex fracture network, and the output after well opening can be improved by pressure differential displacement and permeation displacement after pump shutdown.
【作者单位】：中国石油勘探开发研究院;中国石油勘探开发研究院廊坊分院;国家能源致密油气研发中心;中国石油大学(北京)石油工程教育部重点实验室;
【基金】：国家科技重大专项资助项目(2016ZX05023)~~
【分类号】：TE357

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