A four-cylinder hydraulic pumping unit

Abstract

A four-cylinder type hydraulic pumping unit comprises two operating cylinders, energy accumulators, a hydraulic oil pump, a reversing valve and a pumping well rod, wherein rodless chambers of the operating cylinders are connected with the hydraulic oil pump through a pipeline provided with the reversing valve. The four-cylinder type hydraulic pumping unit is characterized by further comprising two balance cylinders, the operating cylinders and the balance cylinders symmetrically and crossly enclose the well rod in pairwise, piston rods of the operating cylinders and the balance cylinders and the well rod are fixedly connected onto a connecting frame, cylinder blocks of the operating cylinders and the balance cylinders are fixed on a workbench, a through hole allowing the well rod to penetrate through is arranged on the workbench, the well rod extends into the oil well, and rodless chambers of the balance cylinders are connected with the energy accumulators through a pipeline additionally provided with an oil way which is connected with a small hydraulic oil pump. Pressure of the energy accumulators enables the balance cylinders to generate upward thrust, so that the mass of the well rod is counteracted, and further, gravitational potential energy of the well rod is recovered, energy consumption is reduced greatly, and pumping efficiency is improved.

Description

technical field [0001] The invention relates to oil pumping equipment used in oil fields, in particular to a four-cylinder hydraulic pumping unit. Background technique [0002] Most of the oilfields in the world today use rod-type pumping units, which pump crude oil to the ground by driving the sucker rod to reciprocate the plunger of the downhole pump. Since the depth of the oil well is usually thousands of meters, the weight of the sucker rod also varies with the depth of the oil well. According to current investigations in various oil fields in China and Southeast Asia, most of them are in the range of 5-15 tons. Now the oil field routinely uses beam-type mechanical pumping units (commonly known as kowtow machines). [0003] In order to exploit deep oil wells and heavy oil wells, pumping units with large loads must be used, so it is necessary to develop long-stroke and large-load pumping units. Although the beam pumping unit has the advantages of simple structure and eas...

AI Technical Summary

Problems solved by technology

[0003] In order to exploit deep oil wells and heavy oil wells, pumping units with large loads must be used, so it is necessary to develop long-stroke and large-load pumping units. Although the beam pumping unit has the advantages of simple structure and easy maintenance, it is the current traditional It is the most widely used pumping unit in the world, but there are many problems in the design of long stroke and large load. 1. The size of the mechanism is too large. For example, the weight of the whole machine of the 12-type pump is about 34 tons; 2. The balance is poor, and the length of the beam exceeds 9 meters. The weight of the balance part is also more than 10 tons. 3 Due to the increase in size, the force condition of the whole machine is also worse. These bring difficulties to installation, transportation and well site layout

It can be seen that the conventional kowtow machine is difficult to meet the requirements of long stroke, low stroke and large load

[0004] In order to solve the above technical problems, people have designed hydraulic oil pumping equipment to replace the traditional kowtow machine. The existing hydraulic oil pumping units generally use a single working hydraulic cylinder, and the gravitational potential energy of the well rod cannot be effectively recovered, resulting in Increased energy consumption, room for improvement

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