Air balance hydraulic pumping unit for offshore platform

Abstract

The invention discloses an air balance hydraulic pumping unit for an offshore platform. The air balance hydraulic pumping unit for an offshore platform comprises a rope hanger, a movable pulley, a flexible connection mechanism, a fixed pulley, an energy accumulator, a bracket, a composite step type hydraulic cylinder and a hydraulic pump system. A hydraulic cylinder is arranged in the inner space of a truss type rack; the lower end of a piston rod is connected with the movable pulley; and the energy accumulator is arranged at the top of the bracket. The pumping unit is of a simple structure and convenient to install, has more obvious energy-saving effect than a conventional energy-saving type pumping unit, and overcomes the shortcoming that the traditional pumping unit cannot meet the requirements of offshore oil production due to the large volume, large floor area and large weigh of the entire machine. The invention provides a novel oil production apparatus for later-stage development of an offshore oil field in China.

Description

Technical field [0001] The invention is a new type of gas-balanced hydraulic pumping unit, which is mainly applied to the technical field of rod pump oil extraction in oil fields, and is particularly suitable for later development of offshore oil fields. Background technique [0002] The hydraulic pumping unit uses hydraulic transmission to convert the high-speed rotational motion of the engine into vertical linear reciprocating motion at the suspension point of the pumping unit through hydraulic actuators (hydraulic cylinders or hydraulic motors), and drives the downhole pumps to achieve oil extraction operations. Practice has proved that hydraulic pumping units have the following advantages: hydraulic pumping units not only break the structural principle of beam pumping units, convert electrical energy into rotary motion, and then use mechanical methods to convert rotary motion into linear reciprocating motion. The method of exercise and high transmission efficiency can realize...

AI Technical Summary

Problems solved by technology

The hydraulic pumping units that have been designed so far include chain-type long-stroke hydraulic pumping units, energy-saving hydraulic pumping units with combined hydraulic cylinders, frequency conversion hydraulic closed energy-saving Pumping units, etc., but they are not suitable for offshore oil production due to their own shortcomings. For example, the chain long-stroke pumping unit achieves long strokes and low stroke times, but the structure is more complicated. In addition, because its balance method is a counterweight box Balanced, the overall mass is large; combined hydraulic cylinder energy-saving hydraulic pumping unit has a significant energy-saving effect, but from the perspective of force analysis, the force on the piston rod is asymmetrical, and there is a problem of eccentric wear of the hydraulic cylinder and piston; The frequency conversion hydraulic closed energy-saving pumping unit with balanced load adopts hydraulic counterweight, which has a simple structure, reduces the installed power, and makes the operation safer and more stable. The two-way hydraulic lock in the closed oil circuit can also make the hydraulic pumping unit start The stop is more stable and rapid, which increases the stability and safety of its work, but this pumping unit has the problem of inconvenient workover and abdication; the new energy-saving frequency conversion closed hydraulic pumping unit has a simple structure, and the stroke of the hydraulic cylinder is half of the stroke The height of the whole machine is reduced, and the hydraulic counterweight is used to avoid the use of counterweights, which reduces the weight of the whole machine and can meet the needs of offshore oil production. However, the piston rod is in a state of tension during the upstroke. Considering the performance of the material, When subjected to the same amount of force, the piston rod has a stronger pressure bearing capacity, and the inverted design of the hydraulic cylinder of the air-balanced hydraulic pumping unit for offshore platforms in the present invention not only greatly improves the sealing effect of the hydraulic cylinder, but also makes the piston rod It is always under pressure, and the stroke of the hydraulic cylinder is half of the stroke, which reduces the height of the whole machine

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