Well sucker rod pumps

Well sucker-rod pumps (SSHN) are supplied complete, as well as in separate units and parts. The main part of the SSHN - an integral thick-walled cylinder - is made from precision pipes in cooperation with metallurgical and pipe plants. The working surface of the cylinder undergoes deep nitriding (layer thickness 0.2 ... 0.5 mm, hardness 870–1124 HV) or galvanic chrome plating (layer thickness 0.08 mm, microhardness 700 ... 900 HV).

PKNM provides repair of well sucker rod pumps (SShN) in Perm.

The principle of the pump

When the plungers move downward in the area of cylinders enclosed between the plungers, a vacuum is created, due to which the lower valve block valve opens, and formation fluid enters this zone. A closed upper valve perceives the pressure of the liquid column and creates an additional downward directed load, which helps to overcome hydraulic resistance in the pump and friction forces in the rod string. The latter is very important, because the main obstacle
for pumping out highly viscous fluids, the booms are stuck due to excessive friction forces.
The magnitude of the additional load: P = p dp / 4 (H – h) g, where

dp is the diameter of the plunger-separator;

H - pump suspension depth;
h is the immersion depth of the pump under the dynamic level;

g is the specific gravity of the pumped liquid.

In the subsequent upward stroke of the plungers, the fluid from the interplunger zone is displaced through the open upper valve block valve into the tubing string.

1. Upper plunger
2. Lower plunger
3. Top cylinder
4. Lower cylinder
5. Valve block upper valve
6. Valve block bottom valve