【作者】 黄振华；

【导师】 王宏图；

【作者基本信息】 重庆大学 ， 安全技术及工程， 2011， 硕士

【摘要】 本文以南桐煤矿缓倾斜多煤层下保护层开采工作面为研究对象,通过对保护层开采区域进行工业性试验,确定了工作面开采后的瓦斯压力变化规律;以此为基础,结合保护层工作面的实际情况建立了有限变形下的煤岩固气动态耦合模型,从而获得了保护层开采后卸压瓦斯抽采钻孔优化的基础数据;通过分析多煤层下保护层开采的煤岩卸压特点及卸压瓦斯流动规律,结合现场工业性试验,基于保护层开采的“卸压增透效应”,对其卸压瓦斯抽采参数进行了优化设计,给出了南桐煤矿缓倾斜多煤层下保护层开采的卸压瓦斯抽采的优化设计参数,并验证了其优越性。综上所述,本文主要的研究成果及结论如下:①通过对被保护层考察钻孔瓦斯动力参数变化规律进行工业性测试,分析得到随着保护层工作面的推进,瓦斯压力可以分为正常压力带、压力集中带、过渡变化带和充分卸压带。同时,经测试获得被保护层K4煤层的原始瓦斯压力为3.1Mp。②以保护层开采的卸压流动理论为基础,建立了考虑煤层孔隙率与低渗透煤层渗透率的动态变化的多煤层下保护层开采的固气动态耦合模型;通过模型分析,获得了下保护层开采后被保护层的应力分布规律及保护层开采对被保护层卸压瓦斯抽采钻孔周围的瓦斯压力、孔隙率和渗透率的影响规律。③基于缓倾斜多煤层下保护层开采后被保护层的卸压规律和现场工业性试验中卸压瓦斯动力参数变化“四带”的范围,确定了被保护层卸压瓦斯的相关抽采参数。④在本文现场工业性试验和三维数值模拟的基础上,基于保护层开采的“卸压增透效应”,通过分析多煤层下保护层开采的上伏卸压岩体移动特性及卸压瓦斯运移规律,确定了适合试验区域的卸压瓦斯抽采的最优设计参数,并对其实际应用进行了效果监测。监测结果表明,采用本文设计的卸压瓦斯抽采的优化布置参数使卸压瓦斯平均抽采率达到43%。更多还原

【Abstract】 Based on NaTong coal appropraite mining coal mining under more protective layer as the research object, by protective mining area to determine the industrial test, working the gas pressure changes after mining law;this basis, combined with the reality of the situation protective established limited deformation of coal and rock solid gas dynamic coupling model, and obtain the protective mining pressure relief gas drainage drilling based data optimization;Through the analysis of the protective layer of coal mining under more coal rock discharging pressure characteristics and discharging pressure gas flow pattern, combining with the industrial test, based on the "protective mining roof-floor increase through effect" on its pressure relief gas drainage parameters have been optimized, given how NaTong coal mine appropraite mining under the protective layer coal seam gas extraction pressure relief the optimal design parameters, and proved its superiority. To sum up, this paper main research results and conclusions are as follows:①Through investigation to be protective drilling gas power parameters change regulation industrial test, analysis with the protective work get forward, gas pressure can be divided into normal pressure belt, pressure concentration belt, transition changes take and fully discharging pressure belt. Meanwhile, tested the protective layer get original coal gas pressure K4 for 3.1 Mp.②With the protective mining pressure relief gas flow theory as a foundation, established considering the porosity and low permeability coal seam permeability under the dynamic changes of protective mining coal more solid gas dynamic coupling model; through the model analysis, obtained after mining under cover of the stress distribution law by protective protective layer of protection and pressure relief gas drainage drilling surrounding gas pressure, porosity and permeability of the influence law.③Based on appropraite mining coal after more than under the protective layer by protective roof-floor regularity and on-site industrial test pressure relief gas dynamic parameters of the "four belt" changes, determines the protection scope of the pressure relief gas by relevant extraction parameter.④In this scene industrial test and based on the 3-d numerical simulation, based on the basis of the protective mining "pressure relief increase through effect", through the analysis of the protective layer of coal mining under more pressure relief rock fell on moving characteristics and discharging pressure gas migration rule, obtained the appropriate test area of discharging pressure gas extraction, the optimal design parameters of the actual application effect monitoring.Monitoring results show that, using this design discharging pressure gas extraction optimization layout parameters pressure relief gas to average extraction rate reached 43%.更多还原