Abandoned mine shaft gas leakage prevention and control method

Abstract

The invention provides an abandoned mine shaft gas leakage prevention and control method. The method comprises the steps that gas leakage shafts are determined by observing the gas pressure difference and concentration in the multiple shafts and checking the gas leakage condition of the shafts; when the pressure difference of one or more shafts is a positive value and the sum of the pressure differences of all the shafts is a negative value, overall gas inflow is achieved; all the shafts are connected in parallel through a communicating pipeline, and the pressure differences of all the shafts are controlled to be negative values through valve adjustment arranged on the communicating pipeline; when the pressure difference of one or more shafts is a positive value and the sum of the pressure differences of all the shafts is a positive value, overall gas outflow is achieved; all the shafts are connected in parallel through the communicating pipeline, the effect of reducing the positive pressure difference of an original gas leakage shaft is achieved, extraction equipment is started for extraction, and the sum of the pressure differences of all the shafts is controlled to be a negative value; and potential safety hazards caused by shaft gas leakage are prevented, resource waste and environment pollution caused by gas emptying are avoided, centralized extraction and utilization are achieved, and economic benefits are increased.

Description

technical field [0001] The invention relates to the technical field of gas control in abandoned mines, in particular to a method for preventing and controlling gas leakage in an abandoned mine shaft. Background technique [0002] With the deepening of my country's energy structural reform, a large number of coal mines with operating losses, serious disasters, and resource depletion have been closed and withdrawn one after another, and a large number of shafts are facing closure, and some of the closed shafts have gas leakage to varying degrees. [0003] Most of the underground roadways and shafts of abandoned mines are closed with closed walls and cover plates. Due to the lack of sealing, air flow paths are formed between the shafts. Under the dual effects of natural wind pressure and goaf air pressure, some shafts leak gas to the ground. , is a major safety hazard, while causing environmental pollution and waste of resources. [0004] There are mainly three methods to solv...

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Problems solved by technology

[0005] 1. An exhaust pipe is installed in the shaft of the gas leak, and it is equipped with lightning rods, anti-backfire and other facilities; this method can solve the safety problems caused by gas leakage to a certain extent, but it will increase the environmental pollution and waste of resources.

[0006] 2. Strengthen the sealing by grouting in the wellbore; this method has two disadvantages, one is that it is very difficult to accurately find the leak location, and the other is that high-pressure grouting may cause new airflow channels

[0007] 3. Drainage and utilization; this method has two disadvantages. One is that the transportation and utilization of low-concentration gas is costly and risky. If the gas source is insufficient, it may not have economic benefits; short

Connect the sub-tunnels with the main underground gas extraction pipeline system for gas extraction. The underground air pressure is consistent, and the main and auxiliary wellheads of abandoned mines are sealed. After sealing, there may be pressure differences between the blocked wellheads, natural wind pressure, and goaf air pressure. Caused a gas leak, and did not further deal with the leaked gas

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