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Method for improving coal bed gas recovery efficiency by electrochemistry

A coalbed methane and electrochemical technology, which is applied in the direction of mining fluid, earthwork drilling, wellbore/well components, etc., can solve the problems of small gas production range, insignificant production increase effect, poor applicability, etc., and achieve outstanding substantive characteristics Effect

Active Publication Date: 2017-02-22
TAIYUAN UNIV OF TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, the stimulation effects of these methods are not obvious or the applicability is poor, and there are still a series of problems in production wells, such as slow gas production rate, small gas production range and low recovery rate, especially in soft coal seams.

Method used

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  • Method for improving coal bed gas recovery efficiency by electrochemistry
  • Method for improving coal bed gas recovery efficiency by electrochemistry
  • Method for improving coal bed gas recovery efficiency by electrochemistry

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Effect test

Embodiment approach 1

[0023] Implement a method for electrochemically enhancing the recovery of coalbed methane, the method is carried out according to the following steps:

[0024] a) According to geological characteristics and existing construction technology, drill 7 vertical wells, one of which is liquid injection well 1, and the remaining 6 gas production wells 3 are arranged at 60° around the liquid injection well, and the distance between gas production wells is 430m. Install a disc-shaped iron anode electrode 4 with a diameter of 200 mm and a thickness of 300 mm at the head of the injection well, and install a rod-shaped iron cathode electrode 9 with a diameter of 80 mm and a length of 800 mm at the bottom of the gas production well;

[0025] b) Use insulated wires to connect the anode electrode at the wellhead of the injection well and the cathode electrode at the bottom of each gas production well in series respectively, and connect them to the positive or negative pole of the DC power sup...

Embodiment approach 2

[0030] Implement a method for electrochemically enhancing the recovery of coalbed methane, the method is carried out according to the following steps:

[0031] a) According to geological characteristics and existing construction technology, drill 5 vertical wells, one of which is liquid injection well 1, and the remaining 4 gas production wells 3 are arranged at 90° centered on the liquid injection well, and the distance between gas production wells is 370m. Install a disc-shaped copper anode electrode 4 with a diameter of 150 mm and a thickness of 250 mm at the head of the injection well, and install a rod-shaped copper cathode electrode 9 with a diameter of 60 mm and a length of 700 mm at the bottom of the gas production well;

[0032] b) Use insulated wires to connect the anode electrode at the wellhead of the injection well and the cathode electrode at the bottom of each gas production well in series respectively, and connect them to the positive or negative pole of the DC ...

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Abstract

A method for improving coal bed gas recovery efficiency by electrochemistry is characterized in that a vertical well is drilled, a well net is formed, an anode electrode is placed at a wellhead of a liquid injection well, a cathode electrode is fixed at the bottom of a gas recovery well, fracturing liquid with electrolyte is used for fracturing a coal bed, the electric osmosis direction of an electrochemically modified area points to the bottom of the gas recovery well from the wellhead of the liquid injection well after a direct-current power supply is turned on, water is drained to the gas recovery well, and coal bed gas is displaced. The electrophoretic direction points to the wellhead of the liquid injection well from the bottom of the gas recovery well, solid particles such as pulverized coal and rock powder in coal reservoir pore fractures migrate towards the wellhead of the liquid injection well, and a methane migration channel is dredged. Filling minerals such as calcite and pyrite in the coal reservoir pore fractures are corroded by electrolysis, the number of the fractures is increased, and permeability of the coal bed is improved. The temperature of a coal reservoir and the electrolyte is increased by electric heating action, and desorption-diffusion characteristics of methane are improved. Under the combined action of electric drive, electric plug removal, electric permeability increase, electric heating and the like, the desorption and seepage capacity of the coal reservoir is effectively enhanced, gas production is improved by 3-10 times, and the recovery efficiency is improved to 60-90%.

Description

technical field [0001] The invention relates to a method for increasing the recovery rate of coalbed methane, specifically a method for driving the water in the coalbed to move and carry the coalbed methane by electrochemistry, and driving solid particles such as coal powder and rock powder in the coalbed to drain and remove plugging 1. Filling minerals in dissolution pores and fissures to enhance the permeability of coal reservoirs, increase the temperature of coal reservoirs to strengthen the desorption and diffusion of methane, thereby increasing the recovery rate of coalbed methane. Background technique [0002] The low output of coalbed methane in my country severely restricts the efficient development of coalbed methane and the adjustment of the national energy structure. According to statistics, in 2014, the average daily production of coalbed methane development wells in my country was 644m 3 , the characteristics of multi-well low production are very obvious, while...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): E21B43/16E21B43/24E21B43/30E21B43/26
CPCE21B43/16E21B43/2401E21B43/26E21B43/30
Inventor 郭俊庆康健婷康天合柴肇云张晓雨
Owner TAIYUAN UNIV OF TECH
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