The mechanical analysis on axial bending of pump barrel

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.