断层滑移剪切套管变形模拟及安全控制方法  

Fault Slip Shear Casing Deformation Simulation and Safety Control Methods

作　　者：赵超杰 靳彦欣 闫柯乐 王子栋 Zhao Chaojie;Jin Yanxin;Yan Kele;Wang Zidong(State Key Laboratory of Chemical Safety,Shandong,Qingdao,266104;SINOPEC Research Institute of Safety Engineering Co.,Ltd.,Shandong,Qingdao,266104)

机构地区：[1]化学品安全全国重点实验室,山东青岛266104 [2]中石化安全工程研究院有限公司,山东青岛266104

出　　处：《安全、健康和环境》2025年第3期27-35,共9页Safety Health & Environment

基　　金：国家自然科学基金项目(52304017),构造应力集中区水力压裂诱发断层滑移及套管剪切变形动力学机理研究。

摘　　要：页岩气多级压裂井套管剪切变形问题突出,阻碍了页岩气的安全、高效开发。目前剪切载荷下套管变形力学特征并不清楚,缺乏有效的控制方法。因此,开展了剪切套管变形物模实验,确定了套管变形本构特征,建立了剪切载荷下套管变形数值模型,并通过与实验结果对比验证了准确性。进一步开展了套管的抗剪切变形能力敏感性分析,构建了剪切载荷-套管变形量关系图版,提出了“利用数值模型反演套管变形段地层剪切载荷,结合剪切载荷-套管变形量关系图版,指导邻井套管安全优选”的工程方法。研究表明,剪切载荷下套管变形经历弹性微变形、塑性大变形2个阶段,变形过程的应力-应变曲线符合双线性特征,且大部分套管在2~3 mm位移下即进入塑性大变形阶段。增加套管壁厚能显著提高套管的抗剪切变形能力,但通过套管壁厚、钢级的优选仅可实现对二级、三级套管变形层段的初步安全控制;而对极严重套管变形层段,应考虑优化压裂参数预防断层滑移或降低地层剪切载荷等途径提升井筒完整性水平。The problem of casing shear deformation in shale gas multistage fracturing wells is prominent,which hindering the safe and efficient development of shale gas.At present,the mechanical characteristics of casing deformation under shear load are not clear and effective control methods are lacking.Therefore,the shear casing deformation model experiment was carried out,the constitutive characteristics of casing deformation were determined,and the numerical model of casing deformation under shear load was established,and the accuracy was verified by comparing with the experimental results.The sensitivity analysis of casing anti-shear deformation ability was further carried out,and the shear load-casing deformation relation chart was constructed.The engineering method of“using numerical model to invert formation shear load in casing deformation section,combining with shear load-casing deformation relation chart,guiding casing safety selection in adjacent wells”was proposed.The results showed that the casing deformation under shear load went through two stages of elastic micro-deformation and plastic large deformation.The stress-strain curve of the deformation process accorded with bilinear characteristics,and most casing will enter the plastic large deformation stage at 2~3 mm displacement.Increasing the casing wall thickness can significantly improve the shear deformation resistance of casing,but only the primary safety control of the second and third casing deformation intervals can be achieved through the selection of casing wall thickness and steel grade.For extremely severe casing deformation zones,optimizing fracturing parameters to prevent fault slip or reducing formation shear load should be considered to improve wellbore integrity.

关 键 词：套管变形 断层滑移 剪切载荷 数值模型 页岩气 

分 类 号：TE122.14[石油与天然气工程—油气勘探]