Abstract: In boreholes of different shapes,the load-deflection patterns of the well casing will be different.In a crooked well with variable azimuth,a casing segment between two centralizers will be subjected to non-planar deflection,because the gravity and the axial load exerting on the segment no longer act in the same plane and the lateral force acting on the centralizers in the borehole will change accordingly also.Another important point is that the spacing between two centralizers should be determined by controlling the total eccentricity of the casing,which consists of both the casing deflection and the centralizer's compressive displacement to be below some specified value.In this paper the casing deflection is calculated with Rayleigh-Ritz energy principles,the centralizer's compressive displacement is calculated according to the actual lateral force.A biplanar deflection method is used to solve the space non-planar bending of the casing in the borehole with variable azimuth.The total casing eccentricity is obtained by using the displacement superposition principle.The equations for calculating casing centralizer spacing are established with the casing allowable eccentricity for each kind of borehole,i.e.,the straight inclined hole,(the crooked hole with constant azimuth,the crooked hole) with variable azimuth.Two groups of centralizer spacing plots are presented for reference and analysis.

摘要： 在不同形状的井眼中,套管柱的受力变形计算模式是不一样的。如在变方位的弯曲井眼中,两扶正器间的套管段由于所受重力和轴向载荷不再位于一个平面内,因此将发生非平面弯曲挠曲变形,同时套管扶正器所承受的侧向压缩力也将发生相应变化。此外,扶正器的正确安放间距应当由控制套管弯曲变形和扶正器压缩变形所引起的套管总偏心距不超过某一规定值来确定,而不能仅按这两种变形中的某一种变形来确定。本文较全面地考虑了上述问题,采用瑞利—里兹能量法计算套管的弯曲变形,按扶正器承受的实际侧向力计算其压缩变形,在变方位的弯曲井眼中采用两平面弯曲变形方法研究实际发生的空间非平面弯曲变形,最后以位移的几何迭加原理求出套管在各种井眼中将发生的最大偏心距表达式,控制最大偏心距不超过许可偏心距(文中取等于许可偏心距[c]),建立了斜直、等方位弯曲和变方位弯曲井眼中的一整套套管扶正器安放间距计算公式。通过计算并绘出斜直井眼和变方位变井斜弯曲井眼的两组套管扶正器间距曲线。