预防页岩气套变的橡胶组合套管研制及其抗剪切性能评价  

Development of rubber composite casing for preventing shale gas casing deformation and its shear resistance evaluation

作　　者：陈朝伟 周文高 项德贵 谭鹏 宋建 陈晓军 任乐佳 黄浩 CHEN Zhaowei;ZHOU Wengao;XIANG Degui;TAN Peng;SONG Jian;CHEN Xiaojun;REN Lejia;HUANG Hao(CNPC Engineering Technology R&D Co.,Ltd.,Beijing 102206,China;National Engineering Research Center for Oil&Gas Drilling and Completion Technology,Beijing 102206,China;CNPC Chuanqing Drilling Engineering Company Limited,Chengdu,Sichuan 610051,China;China University of Petroleum,Beijing 102249,China)

机构地区：[1]中国石油工程技术研究院有限公司 [2]油气钻完井技术国家工程研究中心 [3]中国石油川庆钻探工程有限公司 [4]中国石油大学(北京)

出　　处：《天然气工业》2023年第11期131-136,共6页Natural Gas Industry

基　　金：国家自然科学基金项目“流体注入引起的深部页岩断层激活与变形滑移机理研究”(编号:42077247);“山地页岩水力压裂引起断层活化机理与诱发地震灾害防控”(编号:52179114);中国石油油田技术服务有限公司项目“深层页岩气体积压裂关键技术研究与应用”(编号:2022T-002-001);中国石油工程技术研究院有限公司课题“页岩气套变机理与风险预测技术研究”(编号:CPET202224)。

摘　　要：页岩气是目前天然气勘探开发的重点和热点,但页岩气在开发过程中经常会遇到套管变形问题,套管变形不仅影响单井产量,还将缩短井筒生命周期,严重制约着我国页岩气的规模效益开发。为此,利用橡胶吸收裂缝/断层的滑动位移原理,创新设计了一种橡胶组合套管;在综合套管变形量、橡胶膨胀率、下套管摩阻、水泥浆通道和吸水膨胀效率等因素基础上,优选了橡胶胶种,设计橡胶筒成槽孔结构;并利用物理模拟试验系统对橡胶组合套管进行了抗剪切试验,最后利用ABAQUS有限元软件建立了橡胶组合套管位移加载三维力学模型,评价了橡胶组合套管的抗剪切能力。研究结果表明:①膨胀橡胶通过变形和破碎吸收了地层位移载荷,保护了套管,吸收地层滑动量可达到37.2~40.0 mm;②当橡胶筒厚度增加时,套管的变形量随之减小,当橡胶筒厚度达到21.7 mm时,橡胶可以完全吸收施加的位移,避免套管发生变形。结论认为,橡胶组合套管可以有效吸收裂缝/断层的滑动位移,从而保护了内层套管不受影响,进而提高了页岩气井的压裂施工效率,缩短了投产周期,可为我国页岩气的效益开发提供重要的技术支撑。Shale gas is the current focus and hotspot of natural gas exploration and development,but casing deformation happens frequently during it development,which not only impacts single well production,but also shortens the service life of wellbore,seriously restricting the large-scale benefit development of shale gas in China.In this paper,a rubber composite casing is designed according to the principle that rubber can absorb the sliding displacement of fracture/fault.Then,an optimal rubber is selected by taking into account the factors comprehensively such as casing deformation,rubber expansion rate,casing running friction,cement slurry channel,and water absorption and expansion efficiency.In addition,a slotted hole structure is designed for the rubber cylinder,and shear tests are conducted on the rubber composite casing using a physical simulation test system.Finally,a three-dimensional mechanical model for displacement loading of the rubber composite casing is established using ABAQUS finite element software,and the shear resistance of the rubber composite casing is evaluated.And the following research results are obtained.First,the expanded rubber absorbs the displacement load of the formation through deformation and fragmentation,so as to protect the casing.And it can absorb the formation sliding as large as 37.2-40.0 mm.Second,the casing deformation decreases with the increase of rubber cylinder thickness.When the rubber cylinder is 21.7 mm thick,the rubber can absorb all displacement loads,to avoid casing deformation.In conclusion,the rubber composite casing can absorb the sliding displacement of fracture/fault effectively,so as to protect the inner casing from damage and consequently improve the fracturing construction efficiency of shale gas well and shorten the commissioning cycle,which provides an important technical support for the benefit development of shale gas in China.

关 键 词：页岩气 套管变形 大位移量 橡胶组合套管 剪切试验 

分 类 号：TE931.2[石油与天然气工程—石油机械设备]