Single and twin-screw pump system mainly consists of drive device, wellhead device and intermediate tubing. According to its driving mode, it can be divided into three types: electric, hydraulic and mobile. Ground drive (mobile) single, double screw pump is the most widely used, mainly introduces the mobile single, twin-screw pump system.
The motor single and double screw pump system consists of bottom hole, sucker rod string, rod centrator and ground drive system.
Work, rod string rotates, the ground force connection in at the bottom of the sucker rod with single and double screw pump rotor rotation, the well liquid by the lower part of single and double screw pump suction, through the upper, and wellhead flowing from the tubing, and then through the ground pipeline to the metering station.
This way of production is the most convenient, actual use also do not need to install the underground drainage device, because once out of the pump barrel, single and double screw pump rotor and interconnection between oil casing, and have played an important role in drainage. At the same time, the cost of the device is low, which is the ideal method for oil recovery.
2. The structure and working principle of single and double screw pump
(1) the structure of single and double screw pump
Single, double screw pump is composed of stator and rotor. The rotor is a high strength screw with the finish machining and chromium plating. The stator is a pump cylinder, which is made of a solid, oil-resistant, corrosion-resistant synthetic rubber, which is then permanently bonded to a steel shell. Mainly used for transporting oil products.
(2) working principle of single and double screw pump
Single or double screw pump is to rely on the cavity discharge of oil, which is formed between the rotor and stator mutually connected closed chamber, as the rotor turns, closed cavity along the axis direction by suction side migration in the direction of the discharge end. The closed cavity disappears at the discharge end, and the oil in the cavity is squeezed evenly to the discharge end from the suction side. At the same time, a new low pressure cavity is formed at the suction end to absorb the crude oil. In this way, the closed cavity is continuously formed, transported and disappeared, and the crude oil is continuously filled, extruded and discharged, so that the oil in the well is continuously inhaled and lifted to the wellhead through the tubing.