Testing research of improving mine gas drainage under suction by controlling blasting to cause crack;

Design and application of horizontal long borehole for gas drainage in seam roof;

Mechanism and application research of gas drainage in high level drainage tunnel by water sealing system;

A preliminary study on water sealing tunnel drainage technology for gas drainage;

Drilling technology of long hole using for discharging gas from coal seams;

With depth increasing of discharging gas horizontal drilling hole in coal mine of our country,the ratio that drilling hole met soft rock is increasing.

In this paper, layout parameters and technology of deep hole standing shot and methane drainage holes is discussed and implemented plan is designed, test in Panyi Coal Mine shows that it is a very good path to improve methane drainage efficiency by using deep hole standing shot technology in low permeability coal seam.

the author of this paper has come to the conclusion that the prospect of methane drainage in the mine is wide-with an ideal methane generation and store type.

Aiming at the problems of methane accumulation at upper corner angle in coal faces of U-type ventila-tion system,applying percolation theory,gas diffusion law and the law of mass conservation,the mathematical pattern of methane drainage from drills along roof strike was established.

This paper introduces the significance of the gas extraction in the safety in production of coalmine and the modes of the gas extraction,and advances some measures for improving the gas extraction such as pre-extraction of the gas,evaluating the extraction quality and strengthening the management of the gas extraction.

Based on engineering practices and through calculating and analyzing theoretically, this paper summarized a good sealing drill hole method at injection water into seam or gas extraction and the problem of sealing drill hole has been solved.

Based on gas occurrence characteristics in Yangquan coal mining area,an extraction method with economic and technique feasibility is determined through correlation analysis of every kind of gas extraction indexes.

Experience of simultaneous extraction of coal and gas in coal mine is analyzed and an example is used to explain the significance of the organic combination of gas drawing underground with coalbed methan exploiting on ground surface.