Method for sealing gas drainage boreholes at specified positions

Abstract

The invention relates to a method for sealing gas drainage boreholes at specified positions, which comprises a drainage tube, an injection tube and a flexible sleeve, the flexible sleeve is sleeved on the front part of the drainage tube, the injection tube is inserted into the flexible sleeve, and both ends of the flexible sleeve are then tightly bound on the drainage tube; the drainage tube and the injection tube are put into the specified position of a gas drainage borehole together, the injection tube injects sealing filling material into the hermetic flexible sleeve until the flexible sleeve is filled up with the sealing filling material, and after the filling material is expanded, the borehole is sealed. The distance between the outer end of the flexible sleeve and the orifice of theborehole is larger than 8m, and the length of the flexible sleeve is larger than 2m; the flexible sleeve consists of a cotton cloth sleeve section and an antistatic waterproof cloth sleeve section, and the waterproof cloth of the flexible sleeve is used for preventing the seepage of the sealing filling material; and the diameter of the flexible sleeve is larger than the diameter of the gas drainage borehole, so that the radially expanded sealing filling material can be tightly combined with the wall of the borehole. The method has the advantages of good borehole sealing effect, high drained gas concentration, long effective drainage time and simple and quick operation.

Description

technical field [0001] The invention relates to a fixed-point sealing gas drainage borehole method, which is suitable for precisely controlling the sealing depth and sealing position, increasing the sealing depth of the gas drainage borehole, and improving the gas drainage effect. Background technique [0002] Gas is one of the five natural disasters in coal mines, which seriously threatens the safety of mines. In order to prevent and control gas disasters and ensure safe production in mines, mining coal seam or goaf gas by construction drilling is an effective measure to reduce the gas content in coal seam and gas emission in working face. The gas drainage rate of coal mines in my country is generally low. In addition to the influence of geological conditions such as low coal seam permeability coefficient, the main reason is that the quality of drilling hole sealing is poor, resulting in serious gas leakage and low concentration of gas drainage. [0003] At present, my cou...

AI Technical Summary

Problems solved by technology

Since the chemical slurry starts to react within a short time (40-60s) after mixing and stirring, the sealing depth can only reach 4-5m when the winding slurry method is used, and the sealing cannot be effectively avoided due to the loose ring of the roadway. poor hole quality

When the pressure injection grouting method is used to seal the hole, although the sealing depth can be increased, the cross section of the inner section of the gas drainage pipe is increased due to the need to install a baffle plate or bind cotton yarn in the inner section of the gas drainage pipe. If the borehole is deformed to a certain extent or the quality of the borehole is poor, the baffle plate or veil is very likely to be stuck at the reduced or deformed section of the borehole, so that the gas drainage pipe cannot be sent to the designed position in the borehole, resulting in Poor sealing effect or failure

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