深部倾斜盐岩地层套管应力及变形研究  

Study on Casing Stress and Deformation in Deep Inclined Salt Formation

作　　者：韩伟民 闫怡飞[2] 闫相祯[1] Han Weimin;Yan Yifei;Yan Xiangzhen(College of Pipeline and Civil Engineering,China University of Petroleum(Huadong;College of Mechanical and Electronic Engineering,China University of Petroleum(Huadong)

机构地区：[1]中国石油大学(华东)储运与建筑工程学院 [2]中国石油大学(华东)机电工程学院

出　　处：《石油机械》2019年第11期111-117,共7页China Petroleum Machinery

基　　金：国家科技重大专项“高含硫气井完整性评价与安全管控技术”(2016ZX05017-003);国家自然科学基金项目“基于Euler流固耦合模型的储气库井注采管柱气流激励振动机理及动力响应研究”(51804330)

摘　　要：针对川东北盐岩地层套管挤毁变形问题,建立了深部倾斜盐岩地层-水泥环-套管组合体三维有限差分模型,研究了非均匀地应力作用下地层倾角、井斜角、盐岩地层厚度及盐岩力学参数对套管等效应力和变形量的影响。研究结果表明:蠕变1 a时,套管内壁最大等效应力和套管内径最大变形量随着地层倾角和井斜角的增大而同时增大,且地层倾角的影响程度明显大于井斜角,随着盐岩地层岩石力学性质的增强而同时降低,即层间岩石力学性质差异越小,套管安全系数越高;当地层倾角和井斜角较大时,套管的最大变形量随着盐岩地层厚度的增大呈线性增加;利用建立的三维数值模型可以对一定地质条件下的深部倾斜盐岩地层套管的变形趋势进行重现和预测。研究结果对于预防和解决川东北油气田盐岩地层套管损坏问题、优化盐岩地层钻井设计及套管强度设计具有较高的理论参考价值。A three-dimensional finite difference model of deep inclined salt formation-cement sheath-casing is established to address the casing collapse deformation in salt formation in northeastern Sichuan.The casing equivalent stress and deformation influenced by the formation dip,well inclination,salt formation thickness and salt rock mechanical parameters under non-uniform geostress are studied.The results show that under the creep period of 1 year,the maximum equivalent stress of the inner wall of the casing and the maximum deformation of the inner diameter of the casing increase with the formation dip angle and the well inclination angle,but decrease with the rock mechanics properties of salt rock.The influence of the formation dip is obviously larger than the well inclination.Smaller difference of mechanical properties between layers results in higher the safety factor of casing.When the formation dip and well inclination angle are large,the maximum deformation of the casing increases linearly with the thickness of the salt formation.The study results could provide theoretical references for the casing damage prevention and addressing in northeastern Sichuan oil and gas fields and for drilling design optimization and casing stress design.

关 键 词：盐岩地层 套管应力 套管变形 地层倾角 井斜角 等效应力 有限差分模型 

分 类 号：TE925[石油与天然气工程—石油机械设备]