大位移井下套管受力分析和计算

通过分析套管柱在下入过程中的受力 ,导出了套管柱在大位移井中的三维力学模型 .该模型综合考虑了井斜角和方位角的变化、套管柱内外密度的不同、内外泥浆的压力以及套管自身的几何参数、物理参数等因素的影响 .通过对模型的求解 ,可以得到不同井眼类型、泥浆密度、悬浮长度以及不同下套管方案下的套管受力 ,为大位移井下套管作业提供了力学参考 .该模型所开发的软件可用于大位移井下套管摩阻预测和下套管方式的选择 .用该软件对两实例加以验证 ,预测结果与实测结果吻合较好 .

Analysis and Calculation of the Forces Exerting on Casing in the Process of Running into High Angle Deviated Hole

A mechanical model of the casing in 3D borehole was established. In it were considered the influences of deviation angle, the density and pressure differences of the liquids inside and outside casing and the geometric and physical parameters of casing. By solving the mechanical model, the casing bearing forces can be obtained under the conditions of different hole types, mud density, casing suspension length and casing running ways. The software for solving the model was developed, and it can be used for predicting the frictional force in casing running process and for selecting casing running way. Two examples show that the results predicted by the software are identical with ones really measured.