考虑射孔初始损伤的套管强度失效数值研究  

Numerical Study on Casing Strength Failure Considering Initial Perforation Damage

作　　者：刘献博 李军[1,2] 高德伟 柳贡慧 连威[2] 王典 刘鹏林 Liu Xianbo;Li Jun;Gao Dewei;Liu Gonghui;Lian Wei;Wang Dian;Liu Penglin(China University of Petroleum(Beijing);China University of Petroleum(Beijing)at Karamay;Sichuan Changning Natural Gas Development Co.,Ltd.)

机构地区：[1]中国石油大学(北京) [2]中国石油大学(北京)克拉玛依校区 [3]四川长宁天然气开发有限责任公司

出　　处：《石油机械》2023年第10期127-135,共9页China Petroleum Machinery

基　　金：国家自然科学基金青年基金项目“页岩气井多级压裂诱发断层滑移量化计算模型与套管变形控制方法研究”(52204018);国家自然科学基金企业创新发展联合基金项目“海相深层高温高压钻完井工程基础理论及控制方法”(U19B6003-05);中国石油大学(北京)克拉玛依校区引进人才基金项目“页岩油气井全生命周期井筒完整性分析与优化体系构建”(XQZX20220019);长宁区块215.9 mm井眼钻井配套复合冲击钻井工具研究(SCCN-JSZS-2020-0139)。

摘　　要：随着油气资源勘探开发逐渐走向深层和超深层,大药量、高孔密的射孔器得到广泛应用,这给完井管柱的安全性带来了挑战。目前关于射孔套管剩余强度的研究忽略了射孔过程中套管的初始损伤,为此,基于冲击动力学及管柱力学理论,结合现场射孔完井工况,建立了三维射孔数值计算模型,计算了射孔后套管抗挤剩余强度系数;对比分析了射孔及机加孔套管的剩余强度的差异;研究了套管物性参数及射孔参数等对射孔后套管剩余强度的影响规律。研究结果表明:机加孔及射孔后的套管在恒定加载外挤力作用下,应力集中位置首先出现在机加孔周围,然后沿套管轴向方向扩展;射孔后的套管在外挤力作用下,套管内、外壁的应力分布差异较小,应力分布较为均匀;随着套管径厚比的增加,机加孔及射孔后的套管剩余强度均增大,射孔后套管的剩余强度对套管壁厚较为敏感;径厚比相同情况下,随着套管直径的增加,射孔后的套管剩余强度明显增大;射孔孔密增加、射孔相位角减小都会加重套管在射孔过程中的初始损伤。所得结论可为油气井的后续增产及生产方案设计提供参考。As the exploration and development of oil and gas resources gradually move towards deep and ultra-deep layers,large dosage and high perforation density perforators have been widely used,which brings a challenge to the safety of completion strings.At present,the research on the residual strength of perforated casing neglects the initial damage of the casing during the perforating process.Therefore,based on the theories of impact dynamics and string mechanics,combined with the field perforation completion conditions,a 3D perforation numerical calculation model was built to calculate the collapsing residual strength coefficient of the casing after perforation.The difference in residual strength between perforated and machined-hole casings was analyzed.The influences of physical parameters of casing and perforating parameters on the residual strength of the casing after perforation were studied.The study results show that under constantly loaded external pressure,the stress concentration position of the casing firstly appears around the machined hole,and then extends along the axial direction of the casing.For the perforated casing,under the action of external pressure,the stress distribution on inner and outer walls of it changes little,and the stress distribution is relatively uniform.As the diameter to thickness ratio of the casing increases,the residual strengths of the machined hole and perforated casings all increase,and the residual strength of the perforated casing is more sensitive to the casing wall thickness.Under the same diameter to thickness ratio,as the diameter of the casing increases,the residual strength of the perforated casing significantly increases.An increase in perforation density and a decrease in perforating phase angle all aggravate the initial damage of the casing during the perforating process.The conclusions provide reference for the subsequent stimulation and production plan design of oil and gas wells.

关 键 词：套管射孔 初始损伤 抗挤强度 射孔参数 射孔孔道 Mises应力 

分 类 号：TE925[石油与天然气工程—石油机械设备]