页岩油储层压裂液渗吸驱油机理研究
Imbibition displacement mechanism of fracturing fluid in shale oil reservoir
刘绪钢 1李国锋 1李雷 2王锐霞 2方彦明2
作者信息
- 1. 中国石化华北油气分公司,河南郑州 450006;中国石化深层煤层气勘探开发重点实验室,河南郑州 450006
- 2. 中国石化华北油气分公司,河南郑州 450006
- 折叠
摘要
压裂液渗吸驱油是当前页岩油储层提高采收率的重要技术手段.通过评价压裂液润湿改性处理剂对渗吸驱油效率的影响,研究页岩油储层压裂渗吸驱油机理.测试了处理剂的表面张力、界面张力和润湿性,考察了处理剂与常规压裂液的配伍性,评价了不同孔隙尺寸岩样的渗吸驱油效率.结果表明:阴离子表面活性剂AOS(α-烯基磺酸钠)为最佳压裂液润湿改性处理剂,颗粒、基质和裂缝岩样的渗吸驱油效率分别为8.17％、17.55％和37.37％.证实渗吸驱油动力包括浮力、浮力-毛细管力和毛细管力,改性剂通过改变岩石润湿性增强毛细管力提高驱油效率,较常规压裂液渗吸驱油效率提高约152.9％.孔隙结构影响渗吸驱油的主导作用力,小孔以毛细管力为主,天然、水力裂缝则以浮力为主.通过研究压裂液渗吸驱油机理,对致密页岩油高效开发具有指导意义.
Abstract
The imbibition displacement of fracturing fluid is a key technique for enhancing oil recovery in shale oil reservoirs.This paper assesses the impact of fracturing fluid wetting modifiers on the efficiency of imbibition displacement and explores the underlying mechanisms at play in shale oil reservoirs.Tests were conducted on the surface tension,interfacial tension,and wettability of the treating agent,alongside investigations into its compatibility with conventional fracturing fluids.Additionally,the imbibition displacement efficiency of rock samples with varying pore sizes was evaluated.The results indicate that the anionic surfactant AOS proved to be the most effective treatment agent for improving the wetting properties of fracturing fluids.The imbibition displacement efficiencies observed were 8.17％for particles,17.55％for matrix,and 37.37％for fractured rock samples.These findings demonstrate that the imbibition displacement force encompasses buoyancy,buoyancy-capillary,and capillary forces.By altering rock wettability,the modifier significantly enhances the capillary force,thus boosting oil displacement efficiency by approximately 152.9％compared to conventional fracturing fluids.The influence of pore structure on the dominant imbibition displacement force was also noted.Capillary forces were predominant in small pores,and buoyancy is the main force for natural and hydraulic fractures.The research on the imbibition displacement mechanism of fracturing fluid provides valuable guidance for the efficient development of tight shale oil reservoirs.
关键词
页岩油/渗吸驱油/润湿改性/孔隙结构/毛细管力Key words
shale oil/imbibition displacement/wetting modification/pore structure/capillary force引用本文复制引用
基金项目
华北油气分公司科研项目(2019CLYXDY-05)
出版年
2024
NETL
NSTL
万方数据