大位移井减阻工具合理安放位置研究

大位移井技术因其具有巨大经济效益并能够满足特殊作业的目的而得以迅速推广应用，但水平井段摩阻扭矩又成为了制约大位移井推广应用的关键因素。为了减少大位移井摩阻扭矩的目的，首先根据用测斜数据，应用3次样条函数拟合井眼轨迹。将多维井段装有减阻工具套管柱作为类连续梁，并考虑弯曲载荷的影响，综合考虑了井斜角、方位角以及套管柱自身几何参数等多因素对套管柱挠曲变形综合影响，以此建立大位移井不同井段套管柱力学模型，完善了部分国外学者计算套管柱挠度“软模型”的不足；进而给出了优化大位移井减阻工具合理安放位置理论计算方法。

PROPER LOCATION OF DRAG-REDUCER IN ERD WELLS

ERD wells are widely adopted due to its great economic benefits and its applicability for special purposes, while the drag along the horizontal section has limited the promotion of ERD wells. In order to reduce the drag, the survey data and cubic spline function are used to match the well trajectory. By taking the multi-dimensional wellbore with drag-reducer equipped casing string as continuous beam, taking into consideration the effects of bending loads, the effects of inclination, azimuth, and the geometric parameters of the casing string on the buckling of the casing string, the mechanical models for the casing string at different sections of the ERD well are established, having improved the "soft model" put forward by foreign scholars for calculating the buckling of casing string. And subsequently the theoretical calculation method for determining the proper location of drag reducer in ERD wells is set up.