Coal powder-prevention tubular discharging and extracting pump

Abstract

The invention provides a coal powder-prevention tubular discharging and extracting pump for pumping liquid in coal bed gas wells, which especially can prevent coal powder from burying pump, blocking the pump and extending the period of pump inspection. The coal powder-prevention tubular discharging and extracting pump comprises a pump cylinder assembly, a plunger assembly, a liquid inlet valve assembly and a fixing device. A hemispherical valve ball enlarges the flow area of a pump valve, improves the speed for well liquid to enter the pump, is beneficial to the discharging of well liquid outof the pump together with the coal powder to prevent the coal powder from blocking the pump; a resetting spring is matched with a positioning pin to reinforce the resetting capacity of the valve ballso that the tubular discharging and extracting pump reduces loss and realizes the purpose of smoothly opening the pump valve under low sinking degree; a coal powder-prevention slot can temporarily contain the coal powder to reduce the abrasion of the coal powder for plungers and pump cylinders; the bottom of the coal powder-prevention slot is provided with jetting holes so that the coal powder ina valve cover is washed by utilizing the well liquid stored in the slot, thereby the discharging and extracting pump realizes the function of self washing to prevent the blockage of the liquid inlet valve from blocking the pump; and a stirrer drives vanes to rotate along with the reciprocating motion of a plunger of the liquid inlet valve to constantly stir the well liquid and deposited coal powder in a sieve tube, thereby preventing coal powder particles from rapidly settling in the sieve tube to result in that the pump is buried by the coal powder.

Description

technical field [0001] The invention relates to a drainage pump used for pumping well fluid in coalbed gas well drainage, in particular to a tube-type drainage pump capable of preventing pulverized coal from being buried in the pump, stuck in the pump and prolonging the pump inspection period. Background technique [0002] At present, my country has drilled more than 3,000 coalbed methane wells, put into production more than 1,500 wells, and will increase at a rate of 1,000 wells every year. The development of special drainage pumps for coalbed methane mining has broad market application prospects. At present, 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. Usually 500-1000 meters), low submergence (only 20-30 meters in stable production), small production capacity (gas production is about 2...

AI Technical Summary

Problems solved by technology

At present, 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. Usually 500-1000 meters), low submergence (only 20-30 meters in stable production), small production capacity (gas production is about 2000 cubic meters per day in stable production, water production is usually less than 10 cubic meters per day), stroke The actual conditions such as small size and low stroke frequency are quite different from oil and gas mines, which makes the use effect of the transplanted oil well pump not ideal. There are problems such as unmatched equipment and serious wear and tear in field use, which are mainly reflected in: (1) When CBM is pumped downhole, the submergence of the pump is low, which makes it difficult to open the pump valve, the filling coefficient and efficiency of the pump are low, and the pump is prone to jamming; (2) There are many coal particles in the well fluid and there are coal coke Such as viscous matter, 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 chamber, causing the pump to be buried; blocked

As a result, the pump inspection period is too short, which seriously affects the normal, economical drainage and high production of coalbed methane wells, and reduces the investment benefit of coalbed methane

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