非均匀地应力下套管水泥环受力研究

Analysis of loading property of casing and cement sheath under nonuniform terrestrial stress

大多数套管损害是由非均匀外载引起的。以非均匀外载为前提,以弹性力学为基础,以套管—水泥环—储层岩体环组合系统为研究对象,对套管及水泥环在理想状况下受非均匀地应力和均匀内外压共同作用时的受力特性进行分析,并依据不同的接触条件推导相应的线性方程组。借助于计算机,计算不同地应力作用下套管、水泥环内部应力及表面受力分布,并可以分析水泥环弹性模量、水泥环厚度与套管接触情况对套管水泥环受力分布的影响。

This paper discusses the loading property of casing and cement sheath by studying the combining system of stratum-cement sheath-casing which is subject to nonuniform geologic stress on the outer surface and hydrostatic pressure on the inner surface.Some linear equation groups for different contact conditions are deduced.We can analyze the situation of casing and cement sheath under different terrestrial stress with computer.The influences of elastic modulus and thickness of cement sheath,thickness of casing,different contacting conditions on the external loading average level and nonuniform degree of casing and cement sheath also can be discussed by using the numerical calculation.