顺煤层钻孔抽采半径与预抽期动态耦合规律

针对煤层瓦斯预抽钻孔盲目布置引起矿井采掘安全隐患凸显及瓦斯治理成本激增的问题,基于瓦斯流量法,对不同钻孔间距下青岗坪煤矿4~(-2)顺煤层瓦斯流量、瓦斯抽采总量与抽采时间对应关系进行考察。结果表明:不同间距(2m、3m、4m、5m)下瓦斯流量均随抽采时间成负指数衰减,抽采总量均随抽采时间成负指数增加,间距越小则初始流量越小而衰减系数越大,间距越大则抽采总量极限值越大;不同间距下瓦斯抽采率均存在极限值,间距越小则极限抽采率增幅越大,间距2m时抽采率达到最大值79%;瓦斯抽采半径与预抽期存在动态耦合关系,综合考虑合理预抽期和瓦斯治理成本,科学确定了现行采掘和抽采条件的有效影响半径,为青岗坪煤矿4-2煤层采掘工作面瓦斯抽采设计提供理论依据。

Study on Dynamic Coupling Law between Drilling Extraction Radius and Pre-pumping Period in Coal Seam

Based on the gas flow method, the corresponding relationship between drilling gas flow and extraction time of 4^-2 coal seam in Qinggangping coal mine under different drilling spacing was investigated, aiming at the problem that blind arrangement of drilling spacing causes prominent safety hidden dangers in mining and gas control cost surges. The results show that: under different drilling spacing (2m, 3m, 4m and 5m), there is a negative exponential attenuation relationship between the extraction flow and time, and a negative exponential increasing relationship between the total amount of extraction and time. The smaller the spacing is, the smaller the initial extraction flow is. Under different drilling spacing, the gas extraction rate has an extreme value. The smaller the spacing, the greater the increase of the limit extraction rate. When the spacing is 2m, the maximum value reaches 79%. There is a dynamic coupling relationship between the gas extraction radius and the pre-pumping period. In the case of comprehensive consideration of the reasonable pre-pumping period and the cost of gas treatment, the effective extraction radius under the current extraction conditions is determined scientifically, which provides a theoretical basis for the gas extraction design of the 4^-2 coal seam mining face in Qinggangping coal mine.