多射孔对套管-水泥环结构强度的影响

结合油井试采工程实际问题,研究了圆形和椭圆形两种形状的多个射孔对套管-水泥环结构强度的影响.给出了外压作用下的双层长圆柱壳结构开任意形状的单个贯穿孔问题的理论解,并用有限元软件ANSYS分别对具有圆形及椭圆形两种形状的单个射孔及多个射孔的套管-水泥环结构在受横向均布外压作用下的孔边应力进行了数值计算.计算结果表明,开单孔情况套管的最大应力的数值解与理论解很接近,每米分布40个圆形射孔情况下的套管-水泥环结构强度比每米分布八个椭圆形射孔情况提高20%以上,因而较为合理.

Influences on strength of casing-cement cylindrical shell with multi-openings

The influences of multi-openings with different shapes on a casing-cement cylindrical shell are studied in this paper,combined with practical engineering of oil wells.The theoretical solution is given to a long double-phase cylindrical shell with a run-through opening of arbitrary shapes subjected to external pressure loading.And numerical calculations with FEM are carried out on a long double-phase cylindrical shell under external pressure loading with single circular opening,single elliptical opening,multi-circular openings and multi-elliptical openings,respectively.The calculation results show that the numerical solutions are very close to the theoretical ones for the cases of single circular opening or elliptical opening.The numerical solutions also show that it is more reasonable for a casing-cement cylindrical shell with forty circular openings per meter,because of its twenty-percent lower stresses than one with eight elliptical openings per meter.