Long plunger type double barrel anti-coal powder drainage pump

Abstract

The invention provides a long-plunger type dual-barrel coal-dust resistant discharging and extracting pump capable of preventing eccentric wear and coal dust from burying pump, blocking pump and prolonging the pump detection period. The pump consists of a centering body, a pump barrel assembly, a piston assembly, a liquid outlet valve and a liquid inlet valve assembly; a centering locking claw is inserted in a lock sleeve of an upper coupling to realize positioning and sealing of the centering body and avoiding eccentric wear between the plunger and the pump barrel; an internal barrel can prevent the deposited coal dust in the annulus of a bar pipe from entering the gap between the plunger and the pump barrel; the coal dust is dropped back to a tail pipe through the annual cavity between the external barrel and the pump barrel to prevent the coal dust from burying the pump; the structure of the long-plunger short pump barrel can promptly discharge the coal dust in the gap between the plunger and the pump barrel, so as to protect the internal and external working surfaces of the pump barrel and preventing the pump from being blocked; the well liquid stored in the coal-dust resistant tank washes the coal dust in the liquid outlet valve cover and the coal dust deposited at the upper part of the liquid outlet valve through a jet orifice, so as to realize an automatic washing function of the liquid outlet valve and preventing the coal dust from jamming the pump; and a spring is cooperated with a liquid inlet valve ball positioning pin, so that the liquid inlet valve ball can be fast reset, and the pump valve under a low submergence can be realized in smooth on and off.

Description

technical field [0001] The invention relates to a drainage pump used for pumping well fluid in coalbed methane well drainage and gas recovery, in particular to a long plunger double pump that can prevent eccentric wear and pulverized coal buried pumps, stuck pumps and prolong the pump inspection period. Cylinder-proof pulverized coal tube drainage pump. Background technique [0002] At present, my country's coalbed methane mining still adopts the technology and experience in oil and gas production, and has not yet formed its own system. More than 90% of coalbed methane wells use oil pumps commonly used in conventional oil and gas mining, mainly some sand control pumps , including spin-type sand control pumps, pump barrels with spiral groove sand control pumps, equal-diameter sand scraping plunger sand control pumps and moving barrel sand control pumps. Due to the actual conditions of coalbed methane wells such as shallow wells, low submergence, low production capacity, small...

AI Technical Summary

Problems solved by technology

Due to the actual conditions of coalbed methane wells such as shallow wells, low submergence, low production capacity, small stroke and low stroke times, which are quite different from oil and gas mines, the effect of the transplanted oil well pump is not ideal. There are problems such as unsuitable equipment and serious wear and tear, which are mainly reflected in: (1) The structure of the long pump barrel and short plunger easily makes the pulverized coal attached to the inner wall of the pump barrel and deposited enter the gap between the plunger and the pump barrel, aggravating the wear of both , when it is serious, it will cause pulverized coal to stick to the plunger, which will reduce the service life of the pump; (2) After the coalbed methane is pumped downhole, the pump's sinking degree is low, which makes it difficult to open the pump valve, the pump's filling factor and pump efficiency are low, and it is easy to occur The pump is stuck; (3) There are many pulverized coal particles in the well fluid accompanied by sticky substances such as coal coke. The flow rate of the liquid at the lower end of the pump is low, and the pulverized coal particles are easy to deposit outside the pump barrel and in the pump cavity, causing buried pump ;(4) In pumping well fluid, the pump valve cannot be reset quickly, causing the pump valve to be blocked; (5) The rod-type sand control pump is not equipped with a centralizing device, and the eccentric wear between the plunger and the pump barrel is relatively serious

As a result, the service life of the pump is low, and the pump inspection cycle is too short, which seriously affects the normal, economical drainage and high production of coalbed methane wells.

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