冻胶段塞密封井筒油气强度研究

Oil and Gas Intensity of Wellbore Sealing by Gel Slug

李晓辉

LI Xiaohui

冻胶段塞在井筒中密封油气的本质及强度鲜有研究。本文采用理论计算，分析了冻胶在井筒中密封油气时的应力应变性质，并结合冻胶抗拉、抗压和抗剪切实验分析，确定冻胶段塞在井筒中密封油气的本质是冻胶的抗剪切性能，其强度可用抗剪切强度描述。计算结果表明：冻胶段塞密封井筒油气的强度与其长度、抗剪切强度成正比，与井筒直径成反比。此理论通过实测数据得以验证。同时还建立了一种测试冻胶抗剪切强度的新方法，并开发了相应的测试装置。研究成果为提高该类冻胶强度的配方研究、相关技术工艺设计提供了理论指导。图6 参10

Few studies had been done about the nature and strength of gel slug which was used to seal oil and gas in wellbore. Based on the theoretical calculation, we analyzed the stress-strain properties of gel in wellbore, and combined with gel tensile, compressive and shear experiment analysis, determined that the gel slug played the role of sealing mainly depending on the gel shear resistance which could be described by the parameter of shear strength. The calculation results showed that the strength of gel slug sealing in wellbore was directly proportional to the length and shear strength, and was inversely proportional to the wellbore diameter. The measured data had verified the theory. At the same time, a new test method of shear strength about gel was established, and the corresponding test equipment was developed. Research result provided a theoretical guidance to formula research with high gel strength and technical process design.