Sticking and leakage preventing pump used for discharge and mining of coal-bed gas well

Abstract

The invention provides a hydraulic force feedback-type discharge and mining pump preventing pulverized coal used for discharge and mining of a coal-bed gas well. The discharge and mining pump mostly comprises a pump cylinder assembly, a plunger assembly and capsule assemblies. During upstroke of the discharge and mining pump, a discharge and mining rod drives the plunger to move upwards and a floating valve is closed. A fixed valve is opened under effect of pressure difference and liquid is absorbed. In the meantime, press rings on capsules are separated from the capsules and the capsules are swelled under elasticity of springs and liquid is absorbed through a filter net and a check valve so that liquid is stored in the capsules. During downstroke, the discharge and mining rod drives a plunger to move downwards and the fixed valve is closed. After the floating valve is opened, liquid below the plunger enters the upper part of the plunger via the floating valve and liquid is discharged. While a press rod and a press ring move downwards to touch the capsule assemblies, the capsule assemblies are extruded. Liquid in the capsules are compressed to feedback liquid flowing channels and sprayed out of the check valve. Pulverized coal particles falling down to a fixed valve seat are flushed and the plunger is driven to suck such that pulverized coal can be discharged. The pump is not buried and stuck by pulverized coal.

Description

technical field [0001] The invention relates to an anti-jamming and leakage pump used for drainage and production of coal bed gas wells. Background technique [0002] In the early stage of coalbed methane well drainage, impurities such as fine coal particles (sand) enter the pump and easily block the pump valve. After entering the stable production period, the dynamic liquid level drops, the bottom hole pressure decreases, and the coalbed methane begins to be sucked out. The fine coal particles (sand) will continue to deposit under the action of its own weight, causing pump valve blockage or pump jamming, shortening the pump inspection cycle and the service life of the drainage pump, seriously affecting the production efficiency of coalbed methane, economic drainage and High and stable production. Simple transplantation of conventional oil and gas field production tubular pump technology cannot meet the drainage requirements of coalbed methane wells. Contents of the inven...

AI Technical Summary

Problems solved by technology

[0003] The invention overcomes the problem of pump stuck due to pulverized coal clogging when coalbed methane wells are drained by conventional tubular pumps, and provides an anti-jamming leak pump for coalbed methane wells, which can use feedback liquid to flush the fixed valve seat to prevent Pulverized coal stuck in the pump, improving pump efficiency, shortening the pump inspection cycle and prolonging the service life of the drainage pump

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