大尺寸超重套管下入过程接箍强度及风险  

Collar Strength and Risk During Lowering of Large-Sized Superheavy Casing

作　　者：冯少波 史君林[3,4] 艾正青 张强 卢强[1,2] 施太和[3] Feng Shaobo;Shi Junlin;Ai Zhengqing;Zhang Qiang;Lu Qiang;Shi Taihe(CNPC R&D Center for Ultradeep Complex Reservoir Exploration and Development;PetroChina Tarim Oilfield Company;National Key Laboratory of Oil and Gas Reservoir Geology and Exploitation,Southwest Petroleum University;School of Mechanical Engineering,Sichuan University of Science&Engineering;School of Mechanical Engineering,Southwest Petroleum University)

机构地区：[1]中国石油天然气集团有限公司超深层复杂油气藏勘探开发技术研发中心,新疆库尔勒市841000 [2]中国石油塔里木油田公司 [3]西南石油大学油气藏地质及开发工程全国重点实验室 [4]四川轻化工大学机械工程学院 [5]西南石油大学机电工程学院

出　　处：《石油机械》2025年第4期114-122,共9页China Petroleum Machinery

基　　金：国家自然科学基金青年科学基金项目“多相瞬变流作用下深层高压高产气井油管柱多场耦合振动特性研究”(52204015);四川省自然科学基金项目“储气库强注强采工况下管柱非线性动力学行为特性研究”(2023NSFSC0920)。

摘　　要：针对万米超深井大尺寸超重套管的下入,传统的分析模型并没有考虑吊卡台阶支撑超重套管接箍的情况,在超重套管下入时套管与接箍缺乏安全性评估。以SDTK1井二开下入ø365.12 mm×13.88 mm套管为例,采用有限元方法建立吊卡-套管-接箍的有限元模型,分析了拉伸、吊卡台阶支撑套管接箍,以及吊卡与套管存在偏心、吊卡磨损等情况,得出了各类情况下吊卡、套管、接箍及管体的应力状态。有限元计算结果表明:在拉伸和悬挂下入套管时,管体螺纹和接箍螺纹的应力状态存在显著差异,吊卡强度和套管螺纹的密封是需要重点关注的部位;吊卡台阶支撑下的套管在7500 kN载荷下入是安全的,但在极限8500 kN载荷时,接箍螺纹存在塑性贯通的风险;偏心和吊卡孔磨损对吊卡影响较大,建议当吊卡孔磨损达到1 mm时更换新吊卡,或者在套管悬重超过500 t时,采用卡瓦型吊卡进行套管下入。所得结论可为超重套管的下入操作和安全性提供参考。The traditional analysis model does not consider the situation where the elevator step supports the superheavy casing collar during lowering of large-sized superheavy casing in ultradeep(~10,000 m)well.Thus,there is no safety evaluation on the casing and collar during the lowering of superheavy casing.Taking the lowering ofø365.12 mm×13.88 mm casing in Well SDTK1 during the second spud-in as an example,a finite element model of elevator-casing-collar was built to analyze the collar of casing lowered by tension or supported by elevator step,as well as the elevator/casing eccentricity and elevator wear.The stress states of the elevator,casing,collar,and pipe body under these conditions were obtained.The finite element calculation results show significant differences in the stress states of pipe body thread and collar thread when the casing is lowered by tension and suspension.The strength of the elevator and the sealing of the casing thread are the key concerns.It is safe to lower the casing under the support of the elevator step at a load of 7500 kN,but the collar thread is prone to plastic penetration at the load of 8500 kN.Eccentricity and elevator hole wear have serious impacts on the elevator.It is recommended to replace the elevator with a new one when the elevator hole wear reaches 1 mm,or use a slip elevator for casing lowering when the suspending weight of the casing exceeds 500 t.The research conclusions provide reference for the lowering operation and safety of superheavy casing.

关 键 词：大尺寸套管 超重套管 套管下入 强度评定 接箍 吊卡 

分 类 号：TE925[石油与天然气工程—石油机械设备]