CALCULATION METHOD OF WELLHEAD PNEUMATIC COMPENSATORS OF SUCKER ROD PUMPS

The paper discusses the calculation method of wellhead pneumatic compensators of sucker rod pumps. It is proposed to install the wellhead pneumatic compensator in the close proximity to the wellhead on the flow line of the well. The calculation of pneumatic compensators was carried out as the calculation of a gas cap. The article discusses such examples of the operation of borehole sucker-rod pumps, when the volume of fluid displaced into the discharge line when the plunger moves down and calculated by the known formulas is greater than the volume of fluid during the upward movement. Examples when fluid is sucked into the well when the plunger moves upward are considered. It is shown that in this case, the magnitude of the degree of non-uniformity of the downhole pump can be significantly greater, almost twice, as much as possible for conventional single-cylinder single-piston pumps. In this regard, the relevance of the use of wellhead pneumatic compensators during the sucker-rod pumping unit operation is no doubt. When calculating the parameters of pneumatic compensators, the values of the pressure pulsation coefficients were taken in the range from 0.10 to 0.35. For the considered examples, the dependences of the instantaneous specific feed of the borehole pump are constructed depending on the angle of rotation of the crank of the pumping unit. For these dependences the magnitude of the change in the volume of the pneumatic compensator for one double stroke of the plunger was determined by integration. The average volume of the gas cushion of pneumatic compensators was determined by the magnitude of the change in the volume of the pneumatic compensator, after which their energy intensity factors were determined. According to the energy intensity values of pneumatic compensators, their initial volumes of gas chambers were determined.