The objective of this study was to develop a sucker-rod pumping unit with a special design and to test it in the given conditions. Such conditions are the wells with a horizontal well bore or controlled directional sidetrack, operated with sucker-rod pumping units within the bore curvature ranges close to 90°.
The tasks of this development were the following: operation of horizontal wells with the maximum bottom hole pressure reduction; increase in the drainage speed; increase in the volume efficiency of the sucker-rod pumping units when operated in horizontal wells in fields in their later stage of development; decrease in the impact of gas on sucker-rod pumping unit operating efficiency.
Complications in operation of wells with horizontal well bores or controlled directional sidetracks are following: restricted use of different types of pumps in lifting operations; the main type is operation of sucker-rod pumping units in the curvature ranges that do not exceed 42°. If exceeded, this value leads to reduction of pump fillage by 14%  or complete pump starvation due to the valve operating with delay when the valve settles into its seat, which leads to leakages through valve foam.