特厚低透气性煤层水力压裂强化抽采技术应用研究

Research on super-thick and low permeability coal seam hydraulic fracturing anti-reflection technology

针对郭家河煤矿主采3号煤层透气性差、本煤层预抽钻孔抽采效果不理想导致工作面回采过程中本煤层瓦斯涌出较大且严重影响矿井正常生产这一问题,矿井在1307工作面回风平巷内选取230m试验段进行水力压裂增透技术研究。根据现场实际情况进行了压裂钻孔间距、参数设计,计算出压裂工艺参数以及适用于郭家河煤矿特厚煤层条件的压裂钻孔封孔工艺。研究得出:压裂过程中,当注水量在30~40 m^3时,压裂半径为15 m;当注水量在50~60 m^3时,压裂半径可达20 m;注水量达到70m^3时,压裂半径可达30 m。主采3煤层的起裂压力为15~20 MPa,水力压裂钻孔封孔工艺采用MKY70型封隔器封孔,能满足封孔要求。通过压裂后增透效果考察,抽采钻孔在瓦斯浓度和瓦斯纯量得到很大提高,该水力压裂工艺及压裂参数对类似条件下的特厚低透煤层压裂技术有重要的指导意义。

In allusion to Guo Jiahe Coal belongs to high gas mine,primary mineable No. 3 coal seam with difference permeability and the effect of pre-drainage from active coal seam was not ideal,so the emission in the process of mining face was bigger and seriously affect on the normal production of mine. In order to solve this problem,it taked 230 m test section in 1307 working face return roadway as the research of hydraulic fracturing anti-reflection technology,to design the drilling space and parameter based on the actual situation,to calculate the hydraulic process parameters and the drilling hole sealing process applicable to Guojiahe Coal Mine. The conclusion was shown that when water injection was 30 ~ 40 m^3,fracture radius was 15 m; when water injection was 50 ~ 60 m^3,fracture radius was 20 m,when water injection was 70 m^3,fracture radius was 30 m,and the crack stress of 3 mine was 15 ~ 20 MPa,the packer of MKY70 applied to the drilling hole sealing was appropriate,by researching anti-reflection effect after fracturing,the concentration of the gas extraction and gas extraction from were greatly improved,this hydraulic process parameters and the drilling hole sealing process achieved important guiding significance for the similar conditions.