基于纳米流控系统的超弹套管保护套结构原理与性能试验

Structure and Performance Test of Super Elastic Casing Protective Nanofluidic System-Based Protective Casing Jacket

章娅菲 祁珊珊 窦益华

ZHANG Yafei QI Shanshan DOU Yihua

西安石油大学机械工程学院, 陕西西安 710065

Mechanical Engineering College, Xi'an Shiyou University, Xi'an, Shaanxi, 710065, China

针对套管承受非均匀载荷及压力温度变化引起的气窜问题，利用纳米流控能量吸收/转换系统所具有的独特的温变压变特性，提出了在套管外包覆超弹套管保护套的方法，介绍了超弹套管保护套的结构和原理，并通过压力-体积试验和温变试验测试了MFI型沸石-水流控系统的性能。压力-体积试验发现，MFI型沸石-水流控系统中的功能流体（水）随外界压力与温度的变化自发流入或流出纳米多孔介质的孔道，通过体积变化平衡外压或温度的变化，降低套管失效概率与气窜风险。温变试验发现，当温度在30~75℃之间变化时，该套管保护套的压力阈值随温度升高而降低，其形变能力随温度升高而增强，具有优异的温变工作特性。研究表明，套管外包覆合适超弹套管保护套，利用其温度和压力变化下良好的变形协调能力，可有效解决复杂工况下套管外气窜的问题。

In order to relieve the non-uniform loading on casing and solve gas channeling problems from pressure and temperature changes,this paper presents a super elastic casing protective jacket.It is a nanofluidic system-based jacket for the casing that has unique volume changing characteristic under varied temperature and pressure.The scientific principles underpinning the jacket design are found in nanofluid structures.For example,the MFI zeolite-water system is taken as an example filling formula and the performance is evaluated from pressure-volume test and temperature change test.The pressure-volume test shows that the functional fluid(water) can flow into and out of the nanopores spontaneously with the change of external pressure and temperature.Such flow balances the change of external pressure and temperature via volume change and helps to reduce the risk of casing failure and gas channeling.In the temperature change test,the casing protective jacket exhibits excellent characteristics.The threshold pressure decreases with the rising of environmental temperature,and its deformability increases with the rising of environmental temperature between 30 to 75℃.Studies indicates that gas channeling under complex conditions can be effectively solved by protective jacket with appropriate formula based on the strength of its deformation coordination ability under pressure and temperature changing.

国家自然科学基金项目"页岩气水平井压裂与生产套管变形机理及其控制机制研究"（编号：51674199）、陕西省自然科学基础研究计划项目"温差驱动液体渗流纳米多孔介质能量转换机理研究"（编号：2017JQ5108）和西安石油大学研究生创新与实践能力培养计划（编号：YCS17211008）联合资助。

https://doi.org/10.11911/syztjs.2018156