斜井抽油杆扶正器安放间距三维计算

在斜井抽油杆上合理布置扶正器可减缓抽油杆与油管的相互磨损，延长油井免修期，降低生产成本。采用力学分析的方法，结合井眼轨迹数据，由下到上逐跨计算了抽油杆柱的扶正器间距和轴向力。假定抽油杆柱上只有扶正器处与油管接触，通过反复试算确定了两相邻扶正器之间的合适间距、上扶正器处的轴向力和侧向力。研究结果表明，相邻两扶正器的间距取决于上述轴向力、侧向力、井眼几何尺寸、杆抗弯刚度和杆与管间隙的大小。抽油杆柱最下端作用力的大小取决于液体压强、柱塞重量、摩擦力、液体阻力和惯性。而侧向力的大小取决于井眼见何尺寸、轴向力和抽油杆重量。计算实例及现场应用均表明三维计算方法是可行的。

Three-dimensional calculation of sucker rod centralizer spacing in deviated well

Wear between sucker rod string and tubing string in a deviated well can be reduced by the proper setting of sucker rod centralizers. Thereby the overhaul period of the well can be extended and the production coct can be cut down. The axial load and centralizer spacing from the bottom tO the top are calculated by using the mechanical analysis method and the well trajectory data. By assuming the rod string contacting with the tubing string only at the centralizers, the rational centralizer spacing and the axial force and lateral force on the upper centralizer are determined by means of repeated pilot calculation. Investigation shows that the space between two adjacent centralizers depends on the above-mentioned axial force, lateral force, wellbore dimensions, bending rigidity and clearance between the rod and the tubing; the force on the end of the rod string depends on the liquid pressure, plunger weight, friction, liquid resistance and inertia; and the lateral foree depends on the wellbore dimensions, axial force and rod weight. The calculation instance and application show that the above-mentioned method of calculation is feasible.