【作者】 王华；

【导师】 王飞；

【作者基本信息】 太原理工大学 ， 安全科学与工程， 2019， 硕士

【摘要】 我国生产矿井主要以井工开采为主,在煤矿五大灾害中,瓦斯灾害引发的事故起数和伤亡人数所占比列居高,矿井瓦斯是一直萦绕在煤矿工作者耳边的安全隐患,坚硬顶板综采工作面开采过程中,采空区瓦斯富集问题严重。高位钻孔抽采技术作为一种高效、经济的采空区瓦斯治理方法,其抽采效果主要取决于裂隙带高度的确定,各矿区由于煤层开采强度、开采深度、顶板岩性及采空区顶板管理工艺的差异性,顶板裂隙发育高度各异。本文以潞安集团潞宁煤业为工程背景,采用实验室测试、理论研究和现场实地考察等手段,对潞宁矿2号煤层工作面瓦斯来源、采空区竖向“三带”、采空区瓦斯运移规律及高位钻孔布置参数等展开了全面的分析研究,解决了坚硬顶板综采面采空区瓦斯向工作面大量涌出的问题。围绕采空区瓦斯抽采技术的优化应用,在研究过程中主要取得以下成果:（1）研究的前期阶段对24102工作面的瓦斯基础参数、坚硬顶板弱化方式、瓦斯来源进行了现场实测分析,确定24102工作面平均瓦斯涌出量为11.00m³/min,其中,采空区平均瓦斯涌出量为5.76m³/min,占工作面涌出量的52.36%;（2）结合潞宁煤矿2号煤层顶底板岩石力学参数的测试结果,通过理论计算、FLAC^3D模拟、钻孔窥视仪窥探技术手段对24102工作面采空区顶板裂隙带的发育高度进行了研究,研究结果表明,24102工作面采空区顶板裂隙带的发育高度为16⁵2m,且在工作面推进过程中钻孔窥视仪显示,距煤层顶板35m左右裂隙发育良好;（3）结合竖向“三带”的分布高度对不同抽采方式下采空区瓦斯运移规律进行了FLUENT模拟研究,研究结果表明,埋管抽采采空区瓦斯的层位有限,当瓦斯涌出量较大时,为确保工作面瓦斯浓度在可控范围内,需采用埋管和高位钻孔联合立体式的抽采方式治理采空区瓦斯,论证了高位钻孔治理瓦斯的必要性;（4）基于前述研究,针对采空区高位钻孔治理瓦斯的主要参数即终孔的布置层位进行了现场测试研究。通过现场监测24102工作面回风顺槽8组27个测试钻孔的瓦斯抽采浓度和流量,间接分析采空区顶板裂隙动态演化规律,得到采空区高位钻孔终孔的最佳布置层位位于裂隙带的中部,即将终孔布置在距煤层顶板35m左右。基于此,对矿方高位钻孔优化布置应用后,通过持续监测工作面现场瓦斯数据的结果知,工作面瓦斯抽采率有了明显提高,基本达30%以上,上隅角瓦斯浓度降到0.5%以下,达到了经济、高效治理采空区瓦斯的目的,为煤矿安全生产创造了良好的条件。更多还原

【Abstract】 The productive coal mines in China is mainly based on underground mines.The number of accidents and casualties caused by gas accidents is higher in the five major disasters in coal mines,the mine gas is the security risk that has been lingering in the ears of coal mine workers.The problem of gas enrichment in goaf is serious during the mining process of hard roof comprehensive mechanized coal mining face,The drainage technology of high-level drilling as an efficient and economical extraction method of controling the goaf gas,the extraction effect mainly depends on the determination of the fissure field’s height.The development height of roof fissure varies in each mining area due to the differences of coal seam mining intensity,mining depth,roof lithology and roof management technology in goaf.This paper takes Lu’an group Luning coal industry corporation as the engineering background,The gas source in the No.2coal seam face in Luning Mine,the vertical“three belts”of the goaf,the gas migration law in the goaf and the high-level drilling arrangement parameters were comprehensively analyzed through laboratory tests,theoretical research and on-site field investigations.The problem that the gas gushs from goaf to working face is solved under the condition of hard roof comprehensive mechanized coal mining face.The paper mainly achieve the following results around the optimization and application of the goaf gas drainage technology.(1)In the early stage of the study,the gas basic parameters of the 24102working face,the method of weakening roof and the gas source were analyzed by field measurement analysis.It was determined that the average amount of gas emission of 24102 working face was 11.00m~3/min,and the average amount of gas emission of goaf was 5.76m~3/min,accounting for 52.36%of the total gas emission amount of working face;(2)Combined with the test results of rock mechanics parameters of No.2coal seam roof and floor in Luning coal mine,the development height of roof fissure zone in the goaf of 24102 working face was studied through theoretical analysis,FLAC~3DD simulation and borehole peep technical instrument.The research results show that the development height of the roof fissure zone in the goaf of 24102 working face is 16~52m,and the borehole peeper shows that the crack is well developed about 35m away from the roof of the coal seam during the process of mining face advancing;(3)The FLUENT simulation study was carried out on the migration law of gas in the goaf under different extraction modes according to the distribution height of the vertical"three belts",The study shows that the gas extraction by intubation has a limited horizon.When the gas emission is large,it is necessary to use the combination of intubation and high-level drilling to control the goaf gas in a three-dimensional manner,in order to ensure the gas concentration in the working face is within the controllable range,the necessity of high-level drilling to control gas is proved;(4)Based on the above research,they were tested in the field that the main parameters of the goaf gas control by the high-level borehole that is the layout level of the final hole.By monitoring the gas extraction concentration and flow rate of 8 groups 27 test boreholes in air return tunnel of 24102 working face on site,the dynamic evolution law of roof crack was indirectly analyzed.It is found that the optimal placement of the final hole of the high-level borehole in the goaf is in the middle of the fissure field,which is the final hole was arranged about35m away from the coal seam roof.Based on this,after the application of optimized layout of high-level borehole in the mine,it is known that the gas extraction rate of the working surface has been significantly improved by the continuous monitoring data at the site,which is basically above 30%,and the gas concentration of the upper corner has dropped below 0.5%.Which has achieved the purpose of economic and efficient treatment of goaf gas and created good conditions for the safe production of the coal mine.更多还原