页岩气水平井多级压裂过程中套管变形研究综述  

Overview of Casing Deformation in Multistage Fracturing of Shale Gas Horizontal Wells

作　　者：席岩[1] 李军[1] 柳贡慧[1,2] 曾义金[3] 李剑平 Xi Yan;Li Jun;Liu Gonghui;Zeng Yijin;Li Jianping(China University of Petroleum, Beijing 102249, China;Beijing University of Technology, Beijing 100022, China;Sinopec Research Institute of Petroleum Engineering, Beijing 100029, China;CNPC Logging, Xi’an, Shaanxi 710000, China)

机构地区：[1]中国石油大学,北京102249 [2]北京工业大学,北京100022 [3]中国石化石油工程技术研究院,北京100029 [4]中国石油测井有限公司,陕西西安710000

出　　处：《特种油气藏》2019年第1期1-6,共6页Special Oil & Gas Reservoirs

基　　金：国家自然科学基金联合基金重点项目"页岩气水平井井筒完整性失效机理与控制方法"(U1762211);中国石油重大科技专项"复杂应力条件下固井水泥环和套管柱完整性分析"(2016E0608)

摘　　要：针对页岩气水平井多级压裂过程中出现的套管变形问题,运用力学实验手段以及数值分析方法,计算了多级压裂过程中套管强度以及应力变化,研究了环空束缚流体、岩性界面、温压交变、地层滑移对套管应力以及应变的影响。研究表明:页岩气井压裂过程中套管变形以剪切变形和挤压变形为主,变形点具有从趾端到跟端不断增多的分布特点,且部分位置变形情况随时间推移不断加剧;环空束缚流体、岩性界面显著提升了套管应力,但不是导致套管应力超过屈服强度的充分原因;套管应力超过屈服强度后,温压交变将会加剧挤压变形程度;断层沿天然裂缝或层理弱面滑移导致套管发生剪切变形,增加套管厚度或者采用分段固井方式有利于降低套管剪切变形风险。研究成果可为压裂过程中套管完整性设计及控制提供参考,具有重要理论和工程意义。In order to solve the casing deformation problem occurred in the multistage fracturing process of shale gas horizontal wells, the mechanical experiment and numerical analysis methods were used to calculate the casing strength and stress variation in multistage fracturing process, and study the effect of annular bound fluid, temperature and pressure alternation and formation slip on casing stress and strain. The study results show that during shale gas well fracturing, the casing deformation is dominated by shear deformation and compressional deformation, the deformation points are increasing from toe end to heel end, and the deformation in some locations is aggravated with time;the annular bound fluid and lithologic interface remarkably increase the casing stress, but they are not the sufficient reason to cause the casing stress to exceed the yield strength;when the casing stress exceeds the yield strength, the temperature and pressure alternation will aggravate the compressional deformation degree;when the fault slips along natural fracture or weak bedding plane, it causes the casing to suffer from shear deformation, and the increase of casing thickness or the adoption of multistage cementing mode is helpful to reduce the shear deformation risk of casing. The study achievements can provide reference for casing integrity design and control during fracturing, and have important theoretical and engineering significances.

关 键 词：套管变形 多级压裂 热-流-固耦合 温压交变 地层滑移 

分 类 号：TE357[石油与天然气工程—油气田开发工程]