有杆泵泵筒的纵向弯曲机理分析

The mechanical analysis on axial bending of pump barrel

有杆泵在抽油时 ,泵筒会发生纵向弯曲 ,造成其纵向弯曲的机理是 ,当抽油泵柱塞上行时 ,由弯曲的管柱产生的弯曲力矩作用于泵筒所致。其中 ,泵筒上部固定泵柱塞上行时 ,泵筒会发生纵向弯曲 ,其弯曲强度大于管柱 ;而泵筒下部固定泵柱塞上行时 ,泵筒不会发生弯曲 ,只是其柱塞在稠油井中下行时泵筒才会发生纵向弯曲。造成泵筒弯曲的合力在柱塞的上部最大 。

When sucking process, the pump barrel will be axially bended. The cause to make such bending is mainly from the bending force by tubing string applied on to pump barrel by the piston going upward and the bending force is larger than tubing string thus bending on pump barrel happens. The bending of pump barrel will not happen as low part fixed pumping piston going downward that only happens when it works in heavy oil well. The combined force acted on the upper part is higher and abrasive is higher too.