煤矿瓦斯赋存和运移的力学机制及应用研究

发布时间：2018-05-26 16:37

本文选题：煤矿 + 瓦斯赋存　；参考：《大连理工大学》2014年博士论文

【摘要】：瓦斯既是煤矿重要的致灾因素之一,又是重要的清洁能源。导致瓦斯灾害频发的根本原因是瓦斯赋存规律认识不清,而直接原因是瓦斯运移规律认识不清。针对此问题,运用瓦斯地质学、岩石力学、渗流力学和数值仿真等理论,采用理论分析、数值分析和现场实验相结合的研究方法,以受力分析及力的作用结果为主线,围绕煤矿瓦斯赋存和运移的力学机制及应用开展研究,取得了一些有意义的成果。基于前人的研究成果,提出了瓦斯赋存地质构造逐级控制的力学解释：瓦斯赋存受地质构造及其演化控制；构造应力场的性质控制着构造的性质、范围和强度,高级别构造应力场控制低级别构造应力场；通过研究各期构造运动应力场及现代构造应力对构造形成与性质、煤体物理力学性质等的影响,分离出构造挤压剪切区、拉张裂陷区；构造挤压剪切,易破坏煤体形成构造煤,煤层透气性低,利于瓦斯保存和瓦斯富集,控制着瓦斯突出危险区分布；拉张裂陷,应力释放,煤岩层透气性好,有利于瓦斯逸散。系统研究了现代应力作用下断层、褶皱构造对瓦斯赋存尤其瓦斯突出的影响。断层附近是否具有突出危险性主要取决于断层走向与现代应力的关系及构造煤的厚度。断层走向与最大主应力平行时,利于应力释放,有利于瓦斯释放,但断层尖灭端出现应力集中,瓦斯保存条件相对较好,需预防瓦斯事故：随着断层走向与主应力方向夹角的增大,挤压应力影响范围随之增大,突出危险范围也随之增大；断层走向与最大主应力垂直时,有利于断层形成应力闭合空间,煤层渗透性低,从而形成大范围的瓦斯富集区,突出危险性最大。背斜两翼一定范围内剪应力集中,可能是造成该带瓦斯突出严重的原因。建立了矿井瓦斯涌出量反演瓦斯含量及含量取值方法,提出了基于瓦斯地质图的瓦斯资源量计算方法,已被应用到国家能源局组织的全国煤矿瓦斯地质图编制中,计算了22省(区、市)瓦斯资源量,汇总了中国煤矿2000m以浅瓦斯资源量为29.17万亿m3。基于含瓦斯煤岩破裂过程气固耦合作用模型,采用RFPA-GAS软件模拟了上保护层开采过程,实践证明数值试验的结果和实测效果有较好的一致性。在保护层掘进遇构造破坏带或与层间距较小时,易引发瓦斯突出；回采时,卸压膨胀陡变带底板岩体容易产生剪切破坏,遇构造破坏带或与层间距较小时,易诱发瓦斯突出。同时,将近距离上保护层底板分为4个渗流区：原始渗流区(原始应力区)——渗流减速减量区(压缩区)——渗流急剧增速增量区(卸压膨胀陡变区)——渗流平稳增量区(卸压膨胀平稳区)。利用上述研究成果,结合平煤五矿实际,制定了保护层开采期间瓦斯抽采及相关措施,保证了保护层及被保护层采掘安全,实现了煤和瓦斯高效共采。
[Abstract]:Gas is not only one of the important disaster factors in coal mines, but also an important clean energy. The fundamental cause of frequent gas disasters is that the law of gas occurrence is not clear, but the direct reason is that the law of gas migration is not clear. In order to solve this problem, applying the theories of gas geology, rock mechanics, seepage mechanics and numerical simulation, and combining the theoretical analysis, numerical analysis and field experiment, the main line is the force analysis and the action result of the force. The research on mechanical mechanism and application of gas storage and migration in coal mines has made some significant achievements. Based on the previous research results, the mechanical interpretation of the progressive control of gas occurrence geological structure is put forward: the gas occurrence is controlled by geological structure and its evolution, and the nature of tectonic stress field controls the nature, scope and strength of the structure. The high-grade tectonic stress field controls the low-grade tectonic stress field, and by studying the influence of tectonic movement stress field and modern tectonic stress on the formation and properties of the structure, the physical and mechanical properties of coal body, the tectonic compression shear zone is separated. Tensioning rifting area; structure squeezing and shearing, easy to destroy coal body to form structural coal, low permeability of coal seam, favorable to gas preservation and gas enrichment, controlling distribution of gas outburst dangerous area, tension crack, stress release, good permeability of coal and rock strata, In favor of gas escape. The influence of fault and fold structure on gas occurrence, especially gas outburst, under modern stress is systematically studied. Whether there is outburst risk near a fault mainly depends on the relationship between fault strike and modern stress and the thickness of tectonic coal. When the strike of the fault is parallel to the maximum principal stress, it is favorable to the release of the stress and the gas release, but the stress concentration appears at the tip of the fault, and the condition of gas preservation is relatively good. Gas accidents need to be prevented: with the increase of the angle between fault strike and principal stress direction, the influence range of extrusion stress increases and the danger range of outburst increases; when the fault strike is perpendicular to the maximum principal stress, It is favorable to the formation of stress closed space for faults and low permeability of coal seam, thus forming a wide range of gas accumulation areas, with the greatest danger of outburst. Shear stress concentration in a certain range of anticline wings may be the cause of serious gas outburst. In this paper, the method of retrieving gas content and its value from mine gas emission is established, and the calculation method of gas resource quantity based on gas geological map is put forward, which has been applied to the compilation of national coal mine gas geological map organized by the State Energy Bureau. The amount of gas resource in 22 provinces (districts and cities) is calculated, and the amount of shallow gas resource in 2000m coal mine of China is 29.17 trillion m3. Based on the gas-solid coupling model of gas bearing coal and rock fracture process, the mining process of upper protective layer is simulated by RFPA-GAS software. The practice shows that the numerical test results are in good agreement with the measured results. It is easy to cause gas outburst in the excavation of protective layer when the structure failure zone or the interval with the layer is small, and when mining, the rock mass of the floor in the steep zone of pressure relief and expansion is prone to shearing failure, and the gas outburst is easy to be induced when the structural failure zone or the interval between the strata is small. At the same time, The bottom of the protective layer is divided into four percolation zones: the original seepage zone (original stress zone) -seepage deceleration reduction area (compression zone) -seepage rapid increase increment region (pressure relief expansion steep variable zone) -percolation steady. Incremental region (steady zone of pressure relief expansion). Based on the above research results and combined with the actual situation of the No. 5 coal mine, the gas extraction and related measures during the mining of the protective layer are formulated, which ensures the mining safety of the protective layer and the protected layer, and realizes the efficient co-mining of coal and gas.
【学位授予单位】：大连理工大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：TD712.2

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