非均匀载荷下套管偏心对套管强度影响研究  

The Effect of Casing Eccentricity on the Casing Strength under Non-uniformity Load

作　　者：王国华[1] 陈正茂[1] 熊继有[1] 陈华 

机构地区：[1]油气藏地质及开发工程国家重点实验室(西南石油大学),四川成都610500 [2]中国石油川庆钻探工程有限公司国际工程公司,四川成都610015

出　　处：《石油天然气学报》2012年第10期105-107,170,共3页Journal of Oil and Gas Technology

基　　金：国家科技重大专项(2008ZX05046)

摘　　要：通过对复杂地质条件下套管变形趋势分析,发现在相同地层条件下、相同井段处非均匀载荷作用下的等效外挤压力相差很大,致使套管变形程度不一。为了搞清楚出现这种现象的原因,运用相关数值模拟方法对地应力的非均匀程度以及套管偏心度对套管外载的影响规律进行了进一步的研究,结果表明,在90°和270°相对偏心方位套管的最大应力随着偏心距增加而逐渐增加;偏心距越大,套管内壁应力增加幅度越大。这与在非均匀载荷作用下套管内壁最大应力出现方位相同,即套管在非均匀载荷作用下向最小水平主应力方向偏移时,会加剧套管内应力的增加幅度;反之则会减小套管内应力的增加幅度。By analyzing the characteristics and trends of casing deformation under the complex geological conditions,it was found out that under same geologic conditions and in the same section,the external equilibrium pressure was highly different under non-uniform load,therefore the casing deformation was uneven.To clarify the reason of casing deformation,the method of correlated numerical simulation was used to further study the degree of uneven deformation and effect of casing eccentricity on the external load of casings.The results show that the max stress would increased with the increasing eccentric distance at 90° and 270°.The higher the eccentric distance is,the higher the extent of its internal stress increase would be.The position is the same with that of its internal max stress under non-uniform load,that is to say,it migrates to the direction of minimum horizontal and principal stress under non-uniform load,thus the extent of its internal stress increase would be raised,in contrary,the extent would be reduced.

关 键 词：蠕变地层 非均匀载荷 套管偏心度 数值模拟 套管强度 

分 类 号：TE931.2[石油与天然气工程—石油机械设备]