有杆泵抽油斜直井防冲距的计算

Calculation of anti-impact stroke in rod-pumped slant straight holes

在高油气比油田有杆泵采油中，防冲距对抽油泵泵效有较大影响。斜直井中抽油杆柱受力状况不同于直井，故其防冲距的计算也不同于直井。斜宜并检泵作业碰泵时，抽油杆柱由于重力作用在油管内呈螺旋状弯曲。对变形抽油杯柱作受力分析，应用虚功原理推导出油管内变形的抽油杆柱长度；在抽油杆接箍位置把螺旋曲线简化成轴向力作用下的压弯曲线，推导出修正杯柱长度的公式，利用计算机计算出防冲距。用这种方法计算出的防冲距在稠油斜在井上进行了多次检验，计算值与实测值相差很小。

Anti-impact stroke has great influence on the efficiency of subsurface pumps in nd-pumped holes with high gas-oilratio. The forces on the rod string in slant stralght holes is different for that in stheight holes, therefore the calculationof the antishock sboke is different. The rod string in slant srmight holes is deformed under the action of gravity. The defonnation of the rod string is analyzed, the length of the defonned and is worked out according to the virtual work principle, thereby the equation for cormcting the length of the rod string is derived, and the anti-impact stroke is calculated bymeans of computer. The results of checks show that there is litile difference between the calculated values and the measured values.