Compact hydraulic oil pumping machine adopting composited pneumatic-hydraulic cylinder

Abstract

The invention discloses a compact hydraulic oil pumping machine adopting a composited pneumatic-hydraulic cylinder, which comprises a power unit and an oil pumping unit, wherein the oil pumping unit is an executing part of the hydraulic oil pumping machine, directly placed at a wellhead and used for driving a polish rod; and the power unit is connected with the oil pumping unit through an oil pipe and a control cable, and used for controlling and driving the oil pumping unit to move. A closed hydraulic circuit of a three-cavity composited pneumatic-hydraulic cylinder is controlled by using a variable-rotational-speed pump, the up-and-down motion of a piston rod of the composited pneumatic-hydraulic cylinder drives a movable block, and the movable block lifts a beam hanger at the tail end of a steel wire rope wound around the movable block so as to realize an oil pumping process of a sucker-rod pump. A balance weight cavity of the composited pneumatic-hydraulic cylinder is connected with a nitrogen tank so as to realize pneumatic balance. The three-cavity composited pneumatic-hydraulic cylinder and the nitrogen tank both are functional parts and brackets of the oil pumping machine, and a walking beam and a truss are not required. An effect of pneumatic balance and an effect of variable-frequency valveless direct drive are simultaneously achieved by using the three-cavity composited pneumatic-hydraulic cylinder; and the compact hydraulic oil pumping machine is large in load capacity, compact in structure, steplessly regulated in stroke and jig frequency, small in reactive loss of motors, and high in oil pumping efficiency.

Description

technical field [0001] The invention relates to an oil pumping unit, in particular to a compact hydraulic oil pumping unit adopting a composite gas-hydraulic cylinder, which is an oil field driving equipment for rod pumps on the ground. Background technique [0002] Rod pump oil production is the dominant oil production technology at present, and its ground driving equipment is divided into beam pumping unit and beam pumping unit without beam. The beam pumping unit has the advantages of simple structure and high reliability, and is the most commonly used pumping unit at present. However, there are inherent shortcomings determined by the structure: bulky, low oil recovery efficiency, poor balance effect, large power consumption, poor stroke adjustment, and difficult to realize automatic oil recovery. There are a few beamless pumping units for oil production in oilfields. Although the problems of oil production efficiency and stroke adjustment of beam pumping units have been ...

AI Technical Summary

Problems solved by technology

[0004] In view of the shortcomings of existing various types of pumping units such as bulky volume, low efficiency, and poor control performance, the purpose of the present invention is to provide a compact hydraulic pumping unit using a composite air-hydraulic cylinder, which overcomes the efficiency of beam pumping units. The shortcomings of low cost and poor control performance solve the problem of bulky volume of other beamless pumping units

Images