高温环境下套管柱强度设计优化及应用  

Optimization and Application of Casing String Strength Design Under High-Temperature Conditions

作　　者：袁可 杨谋 Yuan Ke;Yang Mou(State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation,Southwest Petroleum University)

机构地区：[1]西南石油大学油气藏地质及开发工程国家重点实验室

出　　处：《石油机械》2023年第1期133-139,共7页China Petroleum Machinery

基　　金：国家自然科学基金项目“干热岩型地热泡沫钻井流体相变行为下井筒温度压力响应特性研究”(52174008)。

摘　　要：深层高温环境对套管力学行为产生较大影响,传统套管柱设计方法仅考虑常温下管柱应力状态,难以适应深层套管柱设计要求。基于弹性力学和热力学理论,结合常温套管应力模型,建立了套管应力与温度作用下的计算模型;基于套管、水泥环和地层耦合体材料特性,分析了热应力作用下套管强度变化特性,建立了高温条件下套管设计优化流程。研究结果表明:在三轴应力作用下套管的抗内压强度增加,抗挤强度减小;高温条件下热应力引起套管三轴强度均减小,管体屈服强度也会减小;热应力产生的轴向应力越大,套管抗挤强度降低幅度越大。所得结果可为深井套管柱强度设计的定量评价提供理论基础。Deep high-temperature environments have considerable effects on the mechanical behaviors of casing, and yet, the conventional casing string design method incorporates only the stress state of casing at normal temperature and thus fails to adapt to deep wells.Given this, based on the elastic mechanics, thermodynamics, and normal-temperature casing stress model, the calculation model for temperature-dependent casing stress is developed.Meanwhile, considering the material characteristics of the coupled system of casing, cement sheath and formations, the casing strength variation under thermal stresses is investigated, and the casing design optimization workflow for high temperature is established.The research shows that in the triaxial stress state, the burst strength grows, and the collapse strength declines.Moreover, the thermal stress induced by high temperature results in the reduction of all of the triaxial strengths and also yield strength of casing.The reduction of the collapse strength is enlarged with the increasing thermal axial stress.The findings of this research provide the theoretical basis for quantitative evaluation of the deep-well casing strength design.

关 键 词：高温环境 热应力 套管柱设计 三轴应力 套管强度 安全系数 

分 类 号：TE921[石油与天然气工程—石油机械设备]