Published November 2017

The study of friction forces in plunger pair of sucker-rod pump curved in directional well

S.A. Mouazamineya

The curved profile of the wellbore of directional wells leads to the appearance of dissimilar forces during the operation of deep-well pump equipment, one of which is boundary friction force in the region of deep pump location. In this case, under the influence of frictional force of the plunger-cylinder pair and the hydraulic resistances in the pump valves, the rod string is underwent to the greatest stress. The radius of curvature of the pump cylinder axis, the clearance between the plunger and the cylinder, the difference between the stiffness of the cylinder and the pump plunger are the defining parameters of these forces. Based on the criteria for simulating rod string operation in directional wells and the analysis of parameters dimensions, as a result of bench studies and field data, experimental dependencies of friction force on the curvature angle of the pump are obtained. It is established that in other equal conditions the difference in cylinder stiffness and the plunger has a large effect on the value of the arising friction forces in the plunger pair of the bent pump. In this case, plug-in type pumps have less rigidity that makes them advisable for use in directional wells.