A new technology of the non-stop intermittent pumping production for beam pumping units has been widely used in PetroChina Daqing oil field. This technology solves the problems that existed in conventional intermittent pumping production, such as a large fluctuation in fluid level, a long idle time, high labor intensity, frozen wellhead in winter, and difficulty in management, etc.
This technology adopts a new strategy. It transforms a long-period intermittent pumping into several short-period intermittent pumping, and changes the crank from shutdown into low-energy swinging motion, at the same time, the plunger piston at downhole is kept stationary while the crank does do non-stop swing operation. Based on the maximum elastic deformation of sucker rods, the optimal swing range and rotary speed of crank are designed by kinematics and load analysis. Meanwhile, the inverter increases the swinging amplitude of crank to build up the gravitational potential energy. With conversion effects from gravitational potential energy to kinetic energy, as well as active control of swing power, a non-impact low energy swinging scheme is formed. The flexible switch between complete-cycle pumping operation and swing operation is successfully realized. According to the situation of a single well, the corresponding working system is formulated.
A total of 124 wells had been used this new technology in petroChina Daqing oil field, the filed application shows that, the non-stop intermittent pumping production stabilizes the fluid level within a reasonable range and guarantees a better pump fillage. Compared with the conventional intermittent pumping prodution, the pump efficiency improved 6.54%, the average energy-saving rate ran up to 34.59%. It is significantly improved the pump efficiency and system efficiency, and achieved the purpose of energy saving. The technology of the non-stop intermittent pumping production for beam pumping units is appropriate for the low-yield well and insufficient liquid well. It will be of great significance for the high-efficiency development of low-yield well.