Sucker-rod pump device for coal seam gas exploitation

Abstract

The invention discloses a sucker-rod pump device for coal seam gas exploitation. The sucker-rod device for the coal seam gas exploitation comprises an oil pumping unit, an oil pipe, a pumping rod, and a sucker-rod pump. The oil pipe is installed inside a casing pipe downhole. The sucker-rod pump comprises a pump cylinder and a plunger matched with each other. The pump cylinder is located at the lower end of the oil pipe and is communicated with the oil pipe. The bottom of the pump cylinder and the bottom of the plunger are both provided with traveling valves. An upper housing of the plunger is provided with a communicating hole. The oil pumping unit is located on the ground and is able to drive the plunger to reciprocate through the pumping rod. The pumping rod is a hollow structure. The joint between the pumping rod and the plunger is provided with an openable sealing structure for closing a casing pipe annular space and a rod tube annular space. The extraction is performed through the interior of the pumping rod upon opening the sealing structure. The sucker-rod pump device is able to use two extraction manners; the appropriate extraction manner can be selected based on the variation of the water yield. The two extraction manners can be continuously switched for continuously and stably reducing the pressure and draining the water in the shaft without well repair operations, accordingly ensuring the continuous and stable production of the coal seam gas well.

Description

technical field [0001] The invention relates to the technical field of coal bed gas exploitation, in particular to a rod pump equipment used for coal bed gas exploitation. Background technique [0002] Coalbed methane refers to the hydrocarbon gas stored in coal seams with methane as the main component, mainly adsorbed on the surface of coal matrix particles, and partially free in coal pores or dissolved in coal seam water. It is an associated mineral resource of coal and belongs to unconventional natural gas. [0003] Coalbed methane is a kind of unconventional natural gas that is formed and exists in coal seams during the coal formation process. Coalbed methane needs to discharge a large amount of water in the coal seam before starting to produce gas. Natural cracks or cleats in the coal seam are usually saturated with water, and coalbed methane is adsorbed on the coal. To produce coalbed methane, it must first be desorbed from the coal . The desorption of coalbed metha...

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Problems solved by technology

With the reduction of water production and the increase of gas production, partial wear of the rod and tube, large power consumption, etc.

[0006] In addition, because the water production rate is variable, the displacement range of the rod pump equipment is small, and it is not suitable for the change of the formation water production rate during the production process of the coalbed methane well. Frequent adjustment of its working parameters and frequent workover are required, which is not only economical. , and it is difficult to meet the requirements of continuous and stable decompression and drainage, which affects the extraction efficiency of coalbed methane

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