油井防偏磨用扶正器下入位置的确定

DETERMINATION OF THE POSITION OF THE OIL WELL ANTI BIAS WEAR IN THE STABILIZER

在确定扶正器下入位置时,常把抽油杆接箍以及扶正器假定为等截面积直杆进行受力分析,使得计算结果误差较大。在抽油机上下冲程运行过程中,带有扶正器的抽油杆柱在油管内做上下往复运动,扶正器本体直径大于抽油杆接箍直径,油管内过流面积减少,产生类似"风洞"及"活塞"效应。针对该现象,考虑两扶正器之间对应井眼(段)的曲率半径和全角变化情况,计算了两扶正器之间抽油杆横向载荷,采用直接搜索迭代法计算出扶正器的安装间距;在油井每次检泵作业时,根据现场杆、管实际磨损情况对计算结果进行修正。研究结果在1 000余口定向油井应用,油井检泵周期平均延长518天,并正在延续,可为国内其他油田提供借鉴。

When the position of the stabilizer were determined,the sucker rod coupling and the stabilizer were often assumed to be subjected to the force analysis of the equal section area,which caused the large error.In the running process of the oil pumping unit,the sucker rod string with the stabilizer was made up and down in the oil pipe,and the diameter of the body of the stabilizer was larger than the diameter of the sucker rod.So the inner flow area of the pipe is reduced,which could produce similar 'wind tunnel' and 'piston' effect.In view of this phenomenon,the transverse load of sucker rod between two stabilizer was calculated considering the radius of curvature and angle changes of the borehole(section) between the two centralizer.The installation distance of the stabilizer was calculated using direct search iteration method.The calculation results were corrected according to the actual wear of the rod and tube in each pump oil well operation.The application of the research results in the directional well of 1000 showed that oil well pump inspection cycle is extended for 518 days and was continuing.This study could be used for reference for other domestic oil fields.