Composite series-connection drainage and mining device for coal-bed gas well

Abstract

The invention discloses a composite series-connection drainage and mining device for a coal-bed gas well. The device comprises a production casing pipe, a double-layer drainage and mining casing pipe, a guide pipe, a first pump, a second pump, an exhaust pipe and a drainage pipe. A two-stage lifting system composed of the first pump and the second pump in a composite series-connection mode is formed through the double-layer drainage and mining casing pipe and the guide pipe. A first-stage lifting system formed by a first pump is used for forming secondary gas-liquid separation operation on drainage and production liquid, the drainage and production liquid is converted into a laminar flow state from a turbulent flow state, the gas-liquid separation efficiency is improved, and then the drainage and production liquid in the laminar flow state is subjected to second-stage lifting output by a second pump, so that the content of gas in the drainage and production liquid is greatly reduced, the drainage efficiency of the coal-bed gas well is greatly improved, the problems that an extraction pump is low in efficiency and does not discharge water are effectively solved, and then the beneficial technical effects of stable and continuous extraction of the extraction well and continuous and high gas yield are achieved.

Description

technical field [0001] The invention belongs to the technical field of joint mining of coal and coal bed gas, and in particular relates to a compound serial drainage device for coal bed gas wells. 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 a high-quality energy source. and chemical raw materials. The effective use of coalbed methane produced in the process of coal mining can improve my country's energy structure to a certain extent, increase clean gas energy, and make up for the lack of geographical distribution and supply of conventional natural gas in my country. [0003] Taking Lanzhou Yaojie Coal and Electricity Haishiwan Coal Field as an example, the main gas components of this mine are CO 2 and CH 4 . Accord...

AI Technical Summary

Problems solved by technology

However, due to the large amount of CO 2 It will mix with the drainage fluid and be discharged through the oil extraction pipe, resulting in reduced pump efficiency and frequent outflow of water, resulting in a rapid decline in daily gas production and shutdown, thereby affecting the drainage effect of surface drainage wells

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