SUCKER ROD PUMPING UNIT Russian patent published in 2015 - IPC F04B47/00 

FIELD: oil and gas industry.

SUBSTANCE: invention is referred to oil producing industry and may be used during oil extraction. The sucker rod pumping unit comprises cylinder 1 with valve cage 2, saddle 3 and saddle thrust block 4 in its bottom part. The string 5 is coupled to mandrel 6 with longitudinal cut out channels 7 along its body up to support saddle assembly 8 mounted below the mandrel 6. In the up part of the mandrel 6 there is thrust block 9. The cut out channels 7 are intended for borehole fluid passage when discharge valve is open. The mandrel 6 passes through a hollow plunger 10. To the bottom part of the hollow plunger 10 valve sleeve 11 is set so that it is capable to move lengthwise in limited way along the mandrel 6. To the bottom part of the mandrel 6 a rod 12 with stem tip 13 at its end is connected. Length of the rod 12 is equal or more than length of the pump stroke. The rod 12 passes through inner cavity of intake cup assembly, which includes gate 14, collet latch 15 mounted in the top part of the intake cup, and sealing 16. The intake cup assembly (14, 15, 16) is placed in the valve cage 2. The bottom part of the gate 14 is made as outer surface shaped as truncated cone or sphere capable of hermetic interaction with saddle 3. In the top part of the valve 2 there is ledge 17 with diameter less than inner diameter of cylinder 1, valve cage 2 and protrusions at outer surface of the collet latch 15.

EFFECT: reduced hydraulic resistance in the valve unit, improved reliability of valves, improved engineering reliability of the sucker rod pumping unit.

3 cl, 3 dwg