摘要
应用弹塑性有限元方法分析了套管-水泥环-地层系统套管载荷的分布规律。在非均匀地应力条件下,当地层进入塑性时,塑性区为椭圆形,椭圆长轴在最小主应力方向,套管载荷径向分量比弹性解大,但载荷的非均匀性降低。当水泥环进入塑性时,套管载荷大于弹性解,通过提高水泥环的内聚力和摩擦系数以及降低水泥环的弹性模量,可以降低套管载荷。
The distribution law of casing load of casing-cement sheath-stratum system was studied by using elastoplasticity finite element method.Under the condition of unniform in-situ stress,when the stratum enters plasticity,the plastic zone is ellipse and the long radial is in the direction of the minimum horizontal principal stress.The radial component of casing load is larger than that of elastic solution,but the nonuniformity is decreased.When cement sheath enters plasticity,casing load is lager than that of elastic solution too,and the load can be decreased by increasing the cohesion and friction coefficient or by decreasing the elastic modulus of cement sheath.
出处
《钻采工艺》
CAS
北大核心
2009年第5期57-59,127,共3页
Drilling & Production Technology
基金
国家自然科学基金资助(40521002)
关键词
套管载荷
非均匀地应力
弹塑性
有限元方法
casing load,unniform in-situ stress,finite element,elastoplasticity
