基于润湿性改变的低矿化度水驱提高采收率  

Enhanced Oil Recovery by Low Salinity Water Flooding Based on Wettability Change

作　　者：邓九果 姜宇 徐鹏程 屈亚光[3] DENG Jiuguo;JIANG Yu;XU Pengcheng;QU Yaguang(CNOOC(China)Limited Beijing New Energy Branch,Beijing 102209,China;Changqing Industrial Group Co.,Ltd.,Xi'an Shaanxi 710021,China;School of Petroleum Engineering,Yangtze University,Wuhan Hubei 430100,China)

机构地区：[1]中海石油(中国)有限公司北京新能源分公司,北京102209 [2]长庆实业集团有限公司,陕西西安710021 [3]长江大学石油工程学院,湖北武汉430100

出　　处：《当代化工》2024年第6期1351-1356,共6页Contemporary Chemical Industry

基　　金：中国海洋石油集团公司重大专项基金项目(项目编号:KJGG2021-0501)。

摘　　要：低矿化度注水是指向油藏注入含有离子浓度较低的水,通常注入水的矿化度低于5000 mg·L^(-1)。大量的室内实验和少量矿场测试证实了低盐水驱能够提高砂岩和碳酸盐岩油藏的采收率。首先开展了岩石薄片润湿角测试实验,结果表明低矿化度盐水能够改变岩石表面的润湿性,而且不仅与盐水矿化度有关,还与盐水的离子组成和原油组成有一定关系。不同矿化度盐水岩心驱替实验表明,降低注入水的矿化度可以提高岩心的最终采收率,并且在相同矿化度条件下通过优化注入水的离子组成可进一步提高岩心的最终采收率,表明低矿化度水驱具有较大的增油潜力。驱替实验过程中岩心两端压差和出口端流体的pH变化是岩石润湿性变化的直观现象表现,双电层扩散和多离子交换是岩心润湿性变化的主导机制。Low salinity water injection refers to the injection of water with low ion concentration into the reservoir.Usually,the salinity of the injected water is less than 5000 mg·L^(-1).A large number of laboratory experiments and a small amount of field tests have confirmed that low-salt water flooding can improve the recovery of sandstone and carbonate reservoirs.In this paper,the wetting angle test of rock slices was carried out,the results showed that low salinity brine could change the wettability of rock surface,which was not only related to the salinity of brine,but also related to the ionic composition of brine and the composition of crude oil.Core displacement experiments with different salinity brines showed that reducing the salinity of the injected water could improve the ultimate recovery of the core,and under the same salinity conditions,the ultimate recovery of the core could be further improved by optimizing the ion composition of the injected water,indicating that low salinity water flooding has great potential for oil production.During the displacement experiment,the pressure difference between the two ends of the core and the pH value of the fluid at the outlet end were the intuitive phenomena of the change of rock wettability.The double layer diffusion and multi ion exchange were the dominant mechanisms of the change of core wettability.

关 键 词：低矿化度 水驱 润湿性 提高采收率 吸附 制备 测量 

分 类 号：TQ021[化学工程]