水泥环缺失下套管抗爆破强度研究  

On the Anti-blast Strength of Casings with Partial Missing of Cement Sheath

作　　者：贺恒[1] 冯进[1] 刘华为[1] 齐列锋 

机构地区：[1]长江大学机械工程学院,湖北荆州434023

出　　处：《长江大学学报（自科版）（上旬）》2015年第4期52-54,57,共4页JOURNAL OF YANGTZE UNIVERSITY (NATURAL SCIENCE EDITION) SCI ＆ ENG

基　　金：国家自然科学基金项目(51075043)

摘　　要：为了解决油田钻井过程中套管因受内压发生爆破、严重影响钻井工作效率的问题,针对套管-水泥环局部缺失-地层系统,运用ANSYS有限元分析软件研究了套管抗内压初始爆破强度,即套管任意一点的Mises应力刚好达到套管材料的抗拉极限强度时套管内壁面上施加的内压值。研究了水泥环不同周向缺失量和5种地层围压组合下对6种壁厚的无磨损套管抗内压初始爆破强度的影响,并预测了套管的抗内压初始爆破强度。研究结果表明,对于套管-水泥环局部缺失-地层系统,当水泥环缺失量不大时,套管的外壁最先达到抗拉极限强度;当水泥环缺失量大于某一个值时,套管的内壁最先达到抗拉极限强度。To solve the problem of severe influence on the effect of well drilling as casing blasting caused by internal casing pressure in oilfield drillings,for casing-cement sheath partial deletion-formation system,ANSYS finite element analysis software is used to study the initial blast strength against internal pressure of casings,that is the internal pressure exerted on the inner wall of the casings when the Mises stress of any point just reaches the tensile strength limit of the casings.Under the condition of the different circumferential losses of cement sheath and combination of 5kinds of stratum confining pressures,the research is mainly focused on the influence of the initial blast strength against internal pressure of 6kinds of wall thickness of casings without wear,and the prediction of the initial blast strength against internal pressure of casing.The research results show that for the casing-cement sheath partial deletion-formation system,the outer wall of the casing is the first to reach the limit of tensile strength when the deletion of cement sheath is small,the inner wall of the casing is the first to reach the limit of tensile strength when cement sheath deletion is greater than a certain value.

关 键 词：水泥环 局部缺失 套管 初始爆破 Mises应力 有限元分析 

分 类 号：TE931.2[石油与天然气工程—石油机械设备]