阳泉矿区松软低透煤层底板穿层钻孔抽采时间优化

(1.阳泉煤业(集团)有限责任公司,技术中心,山西 阳泉 045000; 2.阳泉煤业(集团)有限责任公司,博士后科研工作站,山西 阳泉 045000; 3.中国矿业大学(北京),应急管理与安全工程学院,北京 100083)

底板穿层钻孔; 抽采时间; COMSOL模拟; 松软煤层; 固气耦合模型

Time optimization of gas drainage from floor crossing boreholes in soft low-permeability coal seams of Yangquan mining area
GUO Chun-sheng1,XU Chao1,2,3,GE Yong3,GENG De-wang3,HU Si-yi3,GONG Ke3

(1.Technical Center,Yangquan Coal Industry(Group)Co.,Ltd.,Yangquan 045000,China; 2.Postdoctoral Research Station,Yangquan Coal Industry(Group)Co.,Ltd.,Yangquan 045000,China; 3.Shool of Emergency Management and Safety Engineering,China University of Mining and Technology,Beijing,Beijing 100083,China)

floor crossing boreholes; gas drainage time; COMSOL simulation; soft coal seam; solid-gas coupled model

备注

确定底板穿层钻孔有效抽采时间对于优化生产接替,提高生产效率有重要意义。在阳泉某矿穿层钻孔施工过程中,由于煤层透气性差、瓦斯含量高、地应力大,原有的抽采设计已不能满足消突与接替需要。在不补打钻孔条件下,延长预抽时间就成为区域瓦斯防突达标的重要途径。文中采用实验室实验、数值模拟与工程验证相结合的研究方法,首先通过实验得到了煤层的瓦斯基础参数,建立了适用于阳泉矿区煤层特点的数值模拟本构模型,并对该煤层底板穿层钻孔不同抽采时间下的抽采效果进行了模拟研究。结果 表明:随着抽采时间的延长,穿层钻孔的影响范围在逐渐增大,瓦斯压力在不断降低。抽采时间为300 d时,抽采钻孔中心点残余瓦斯压力可以降至0.74 MPa以下,可以达到防突要求。最后,通过收集工程实践过程中瓦斯抽采数据,计算得出了煤层残余瓦斯含量,获得了实际残余瓦斯含量与抽采天数的关系,验证了数值模拟结果的正确性。

Determination of gas drainage time in floor crossing boreholes is vital to the production efficiency in coal mines.In one mine in Yangquan area,during the construction of boreholes,the original drainage design can not meet the current demand of production balance due to the low permeability,high gas content and high ground stress in coal seams.Therefore,to extend the drainage time is an important way to reduce the outburst risk level with no further supplementary boreholes drilled.This study used the methods of experiments,numerical simulation and engineering validation to study the gas drainage performance of flooring crossing boreholes with different drainage time.It firstly obtained the basic parameters of coal by experiments and then established a constitutive model to simulate the drainage process.The results showed that with the increase of drainage time,the drainage area increased and the gas pressure decreased.When the drainage time reached 300 days,the residual gas content at the center decreased below 0.74 MPa,which met the demands of outburst prevention standards.At last,by collecting the gas drainage data and calculating the residual gas content,the relationship between residual gas content and drainage time was also obtained,which provided a solid validation to the simulation results.