缓倾斜煤层采动卸压瓦斯储运优势通道演化机理及应用

发布时间：2018-06-16 04:06

  本文选题：优势通道 + 卸压瓦斯　； 参考：《西安科技大学》2017年博士论文

【摘要】：煤炭作为我国现阶段的主要能源,为国民经济快速发展做出了重要贡献。我国煤层瓦斯赋存具有典型的“三高三低”特征,在瓦斯治理的过程中经常造成生产事故。本文针对典型低透气性缓倾斜煤层卸压瓦斯治理难题,采用工程资料收集、理论分析、软件研发、数值模拟以及现场工业性试验相结合的手段,系统分析了缓倾斜煤层采动裂隙时空演化规律及采动卸压瓦斯富集区储运规律,对低透气性缓倾斜煤层卸压瓦斯抽采有着重要的参考价值。论文主要研究工作如下:(1)室实验分析了岩石物质组成成份、细观结构和微观结构,掌握了岩石损伤分布特征;采用单轴抗压、抗拉、抗剪实验分析含初始损伤岩石破坏特征,明晰了时间效应对岩石强度的影响,构建时间对岩石损伤演化影响的本构模型,得出了初始损伤与加载速率耦合效应对岩石破坏影响机理。同时,采用岩石裂纹断裂韧性分析不同加载方式下裂隙演化特征,揭示了覆岩采动裂隙张开和闭合演化机理。(2)基于实践工作面开采技术条件,搭建走向和倾向二维物理模拟实验台,提出了 AW-SNcut的图像识别方法来定量分析实验过程中覆岩采动裂隙演化规律。同时采用数值模拟,定量分析了开采速度和煤层倾角对覆岩采动张开裂隙和闭合裂隙分布特征及演化规律影响。(3)深入分析了缓倾斜工作面3个不同区域直接顶和基本顶破断机理,明确了缓倾斜煤层覆岩“O-X”破断过程中时序性,掌握了缓倾斜煤层采空区充填特征,并分析了覆岩采动裂隙类椭抛带形态特征,建立相应的数学模型,重点分析了关键因素对形态分布特征的影响。在工程实践中,综合采用钻孔窥视仪、微震监测和钻孔抽采浓度分析方法,形成“点+线+面+体”综合一体化监测手段,分析覆岩采动裂隙时空演化规律。(4)基于缓倾斜煤层覆岩采动裂隙时空演化规律,分析了缓倾斜工作面卸压瓦斯来源特征,得出采动过程中卸压瓦斯富集区的运移特征,提出了煤层卸压瓦斯优势通道概念,为缓倾斜煤层工作面卸压瓦斯抽采提供了理论依据。(5)基于超前工作面高位钻孔抽采卸压瓦斯中存在的问题,重点分析了高位钻孔稳定性和抽采卸压瓦斯效果的平衡点。结合高位钻孔和高抽巷抽采卸压瓦斯方法的优点,提出了外错高位巷抽采方法,为卸压瓦斯治理提供了一种高效的抽采方法。研究掌握了缓倾斜煤层覆岩采动裂隙时空演化机理,建立了覆岩采动裂隙分布的类椭抛带数学模型,揭示了卸压瓦斯优势通道的演化机理,进一步提出了合理的卸压瓦斯抽采方法,以上研究成果在典型矿井得到了成功应用,为实现缓倾斜煤层煤与瓦斯共采提供了一定的理论基础。
[Abstract]:Coal, as the main energy of our country at present, has made important contribution to the rapid development of national economy. The occurrence of coal seam gas in China has typical characteristics of "three high and three low", which often cause production accidents in the process of gas control. In this paper, aiming at the difficult problem of relieving pressure gas in typical low permeability gently inclined coal seam, the method of combining engineering data collection, theoretical analysis, software research and development, numerical simulation and field industrial test is adopted. This paper systematically analyzes the temporal and spatial evolution law of mining fissures in gently inclined coal seam and the law of storage and transportation in mining pressure relief gas accumulation area, which has important reference value for low permeability and gentle inclined coal seam. The main research work in this paper is as follows: 1) the composition, microstructure and microstructure of rock are analyzed experimentally, and the characteristics of rock damage distribution are grasped, and the failure characteristics of rock with initial damage are analyzed by uniaxial compression, tensile and shear tests. The influence of time effect on rock strength is clarified, and the constitutive model of time effect on rock damage evolution is established, and the influence mechanism of the coupling effect of initial damage and loading rate on rock failure is obtained. At the same time, crack fracture toughness of rock is used to analyze the characteristics of fracture evolution under different loading modes, and the evolution mechanism of crack opening and closing in overburden mining is revealed. An image recognition method based on AW-SNcut is proposed to quantitatively analyze the evolution of mining fractures in overlying rock during the experiment. At the same time, using numerical simulation, The effects of mining speed and seam inclination angle on the distribution and evolution law of open and closed fractures in overburden rock mining are analyzed quantitatively.) the direct roof and basic roof breaking mechanism in three different regions of gently inclined face are analyzed. The sequence of overburden "O-X" fracture in gently inclined coal seam is defined, the filling characteristics of goaf in gently inclined coal seam are grasped, and the shape characteristics of elliptical throwing zone of mining fissure in overburden coal seam are analyzed, and the corresponding mathematical model is established. The influence of key factors on morphological distribution was analyzed. In engineering practice, the integrated monitoring method of "point, line and surface" is formed by adopting the methods of drilling peep-view, microseismic monitoring and borehole extraction concentration analysis. Based on the temporal and spatial evolution law of overburden mining fissure in gently inclined coal seam, the characteristics of pressure relief gas source in gently inclined working face are analyzed, and the migration characteristics of relief gas accumulation area in mining process are obtained. This paper puts forward the concept of dominant passage of gas relief in coal seam, which provides a theoretical basis for gas drainage in the face of gently inclined coal face. The balance point between the stability of high hole and the effect of gas drainage is analyzed. Combined with the advantages of high hole drilling and high drainage roadway, this paper puts forward a method of extrinsic displacement high level roadway drainage, which provides an efficient method for gas relief treatment. This paper studies and grasps the temporal and spatial evolution mechanism of mining fissure of overlying rock in gently inclined coal seam, establishes the mathematical model of the distribution of mining fissure in overburden rock, and reveals the evolution mechanism of the dominant passage of relief gas. Furthermore, a reasonable method of gas extraction is put forward. The above research results have been successfully applied in typical coal mines, which provides a certain theoretical basis for realizing the joint mining of coal and gas in gently inclined coal seams.
【学位授予单位】：西安科技大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：TD712
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本文编号：2025209