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
邓九果 1姜宇 2徐鹏程 2屈亚光3
作者信息
- 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
- 折叠
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.
Abstract
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Key words
Low salinity/Water flooding/Wettability/Enhanced oil recovery/Adsorption/Preparation/Measurement引用本文复制引用
基金项目
中国海洋石油集团公司重大专项基金项目(KJGG2021-0501)
出版年
2024
NETL
NSTL
万方数据