局部泥岩均匀吸水套管损坏机理  

Mechanism of casing failure caused by local mudstone uniform water soaking

作　　者：罗敏[1] 于海[1] 于成 刘巨保[1] 

机构地区：[1]大庆石油学院机械科学与工程学院,黑龙江大庆163318 [2]哈尔滨飞机工业集团,黑龙江哈尔滨150060

出　　处：《大庆石油学院学报》2007年第6期77-80,共4页Journal of Daqing Petroleum Institute

基　　金：黑龙江省教育厅科学技术项目(10551005)

摘　　要：油田注水开发过程中泥岩吸水蠕变是引起的局部套损的主要原因.考虑套管、地层、水泥环和浸水泥岩,建立有水泥环和无水泥环2种三维有限元模型,模拟浸水体积分别为0.618,0.977,1.418 m3时不同含水质量分数、体积膨胀率对套管等效应力的影响.结果表明:随着泥岩含水质量分数的增加,套管达到屈服时所需的泥岩体积膨胀率减小;当泥岩体积膨胀率一定时,套管等效应力随泥岩含水质量分数的增加而增加;不含水泥环与含水泥环相比,套管等效应力增加12.0%.The casing failure in the water flooded fields is mainly caused by local mudstone uniform water soaking,while the creep of mudstone caused absorbent ground is a main reason for casing failure.This paper establishes two kinds of three-dimensional finite element models,including cement sheath and barring cement sheath,considering casing,formation and immersed mudstone,and simulates the effect of the equivalent stress of casing caused by different mass fractions of water holding,the rate of cubic expansion as the value of water soaked volume is 0.618,0.977,1.418 m3 respectively.The result shows: with mass fractions of water holding in mudstone increasing,the rate of cubic expansion of casing buckle decreases,and when the rate of cubic expansion is a constant,the equivalent stress of casing will increase with mass fractions of water holding in mudstone increasing.The equivalent stress of casing increases by 12 percent,comparing barring cement with cement sheath.The result provides theoretical reference for the research of casing failure.

关 键 词：泥岩蠕变 有限元模型 套管损坏 含水质量分数 

分 类 号：TE256.2[石油与天然气工程—油气井工程]