下面8篇英文学术论文分别刊载在Natural Hazards, September 2014, Volume 73, Issue 3, Natural Hazards, March 2014, Volume 71, Issue 1, Natural Hazards, October 2014, Journal of Mining Science, November 2013, Volume 49, Issue 6, Journal of Mining Science, September 2012, Volume 48, Issue 5, Rock Mechanics and Rock Engineering, February 2014, and Journal of Mining Science, January 2014, Volume 50, Issue 1，现推荐给相关读者，供参考。
Application of in-seam directional drilling technology for gas drainage with benefits to gas outburst control and greenhouse gas reductions in Daning coal mine, China
定向钻井技术在中国大宁煤矿矿井瓦斯抽放中的应用以及在瓦斯突出防治和温室气体减排方面的贡献
Natural Hazards, September 2014, Volume 73, Issue 3, pp 1419-1437
Abstract: Gas outburst disasters are becoming more serious as the underground coal mines become deeper in China, and a thick zone of deformed coal provides conditions favorable to coal and gas outbursts. The Daning coal mine’s main mining seam is the No. 3 coal seam with coal and gas outburst hazard, which often contains two normal coal sub-layers and one deformed sub-layer. Considering both the geological conditions of the coal seam and applications of the in-seam directional longhole drilling technology, a new schematic diagram of in-seam directional longholes for gas drainage is developed. The two borehole layout models of longwall panel and main entries for gas outburst disasters control have been successfully applied. The gas drainage rates of both models are >70 %, and the residual gas contents are both <8 m3/t, which can be considered that the gas outburst disasters were effectively controlled. To better guide gas drainage, gas drainage normal and failure modes have been obtained. Although in-seam directional longhole technology has been successfully applied for regional gas drainage with benefits to gas outburst control, there are also some problems that are detrimental to greenhouse gas reductions in gas drainage and gas utilization. The three main problems are air leakage failure in gas drainage, decreasing gas concentration and a low gas utilization ratio. To address the problems mentioned above, five improvements are suggested.
Characteristics of gas disaster in the Huaibei coalfield and its control and development technologies
淮北煤田瓦斯灾害特征及其防治技术
Natural Hazards, March 2014, Volume 71, Issue 1, pp 85-107
Abstract: The Huaibei coalfield is in the East China Economic Area, which is rich in coal and gas resources. However, hundreds of coal and gas outburst accidents have occurred because of the complex geological structures of the coalfield. Based on theoretical analysis and field statistics, the characteristics of regional geological structures and the coal measure strata evolution in the Huaibei coalfield were researched, and gas resource distribution and gas parameters were statistically analyzed to determine the dominant controlling factors of gas occurrence and gas dynamic disaster. The results indicated that the Huaibei coalfield has undergone complex tectonic evolution, causing obvious differences in gas storage in different blocks of different mining areas, which exhibits a pattern of high amounts of gas in the south and east, and low amounts of gas in the north and west. The coal seam and gas occurrence have a bipolar distribution in the coalfield caused by multiple tectonic movements, and they are deeply buried. Horizontal tectonic stress plays a dominant role in gas outburst, and the thermal evolution and trap effects of magma intrusion increase the possibility and extent of gas outburst. Considering coal seam and gas occurrence characteristics in the coalfield, we propose a new technology for deep coal reservoir reconstruction which combined present underground regional gas control methods and surface well extraction methods. The technology has three effects: developing gas resources, improving coal mining safety level and reducing greenhouse gas emissions, which has been practiced to be effective in coal mines in the Huaibei coalfield.
Characterizing dilatation energy of released gas from underground coal seam by drilling boreholes
地下煤层瓦斯通过钻孔排放时膨胀能的特征化研究
Natural Hazards, October 2014 Date: 14 Oct 2014
Abstract: In order to precisely measure the dilatation energy of the released gas from underground coal seam, this paper initiated a study on the dilatation energy of gas released from underground coal seam by drilling boreholes. Firstly, an in-depth analysis is made on the two major factors causing outburst, which are crustal stress and gas. By establishing mathematical models of unit coal potential energy and gas dilatation energy, authors make a detailed calculation and results comparison. It verifies that the gas dilatation energy is the important and main energy source of a coal seam outburst. Then, the characteristics of dilatation energy of coal seam gas are further stated. Secondly, based on the analysis on the types and features of gas discharge from coal seam and according to the flow field type, this paper divided gas dilatation energy into unidirectional gas dilatation energy, radial gas dilatation energy, and spherical gas dilatation energy. Then, with the assistant of establishing the mathematical model, the software of MATLAB® is used to make numerical calculation on gas dilatation energy release. The results show that dilatation energy of gas released from underground in-seam by drilling boreholes could reflect that coal gas’s ability of expansion work under normal occurrence conditions. Finally, according to the theory of coal seam gas dilatation energy and the features of gas flowing in reducing pipe, on-site measuring method and testing equipment are worked out to measure underground gas dilatation energy. The results of field measurements in a coal mine show that the gas dilatation energy could completely reflect the physical and mechanical properties of crustal stress, gas, and coal. It could be used as a most effective indicator in judging whether coal and gas outburst might occur. Thus, it presents good scientific and practical significances for predicting coal seam outburst.
Parameters of methane condition during phase transition at the outburst-hazardous coal seam edges
突出灾害煤层边缘相变期间甲烷状态参数
Journal of Mining Science, November 2013, Volume 49, Issue 6, pp 908-912 Date: 07 May 2014
Abstract: The authors analyze phase equilibrium of gaseous methane and crystalline hydrate particles in coal pores, considering absorbed heat during phase transition. It is shown that the crystallohydrate-gaseous methane phase equilibrium in small pores can be nonsteady; i.e., on deviation from the phase equilibrium curve, the methane condition parameters change and, as a consequence, increase the deviation. Instantaneous dissociation of crystallohydrates builds up methane pressure, which intensifies outburst hazard and affects the outburst gas balance.
Numerical Analyses of the Major Parameters Affecting the Initiation of Outbursts of Coal and Gas
影响煤与瓦斯突出发生的主要参数数值分析
Rock Mechanics and Rock Engineering, July 2014, Volume 47, Issue 4, pp 1505-1510
Introduction: An outburst of coal and gas is defined as the rapid release of a large quantity of gas in conjunction with the ejection of coal, and possibly associated rock, into the working face or mine workings. The sudden and violent nature of an outburst is hazardous through the mechanical effects of particle ejection and by asphyxiation, poisoning, and possible explosion from the gas emitted. With an increase in mining depth and production, the intensity and frequency of outburst tend to increase. A key challenge to predict and control outburst is to fully understand the major parameters contributing to the initiation of outburst. Previous studies have recognized that these major parameters include stress condition, gassiness of coal seams, geological structures, and mechanical and physical properties of coal (Beamish and Crosdale 1998). It is also widely observed that a coal seam is prone to outburst under the following conditions: high stress, increased mining depth, high gas content ...
Inverse problem solution for estimating gas content and gas diffusion coefficient of coal
估计煤瓦斯含量和瓦斯扩散系数的反解法
Journal of Mining Science, September 2012, Volume 48, Issue 5, pp 781-788
Abstract: The authors suggest the method of interpreting experimental data on gas pressure in a pressure flask containing a coal specimen, that allows defining gas content and gas diffusion coefficient of coal. The offered method is based on solving an inverse problem for a set of diffusion equations each fitting a certain size within the coal specimen grain-size composition. The numerical experiments have shown that a quantitative estimate of gas content has error not higher than a few per cents, even with input data distortion.
Modelling of Longwall Mining-Induced Strata Permeability Change
长臂开采引起的层渗透性变化模拟
Rock Mechanics and Rock Engineering, February 2014
Abstract: The field measurement of permeability within the strata affected by mining is a challenging and expensive task, thus such tests may not be carried out in large numbers to cover all the overburden strata and coal seams being affected by mining. However, numerical modelling in conjunction with a limited number of targeted field measurements can be used efficiently in assessing the impact of mining on a regional scale. This paper presents the results of underground packer testing undertaken at a mine site in New South Wales in Australia and numerical simulations conducted to assess the mining-induced strata permeability change. The underground packer test results indicated that the drivage of main headings (roadways) had induced a significant change in permeability into the solid coal barrier. Permeability increased by more than 50 times at a distance of 11.2–11.5 m from the roadway rib into the solid coal barrier. The tests conducted in the roof strata above the longwall goaf indicated more than 1,000-fold increase in permeability. The measured permeability values varied widely and strangely on a number of occasions; for example the test conducted from the main headings at the 8.2–8.5 m test section in the solid coal barrier showed a decline in permeability value as compared to that at the 11.2–11.5 m section contrary to the expectations. It is envisaged that a number of factors during the tests might have had affected the measured values of permeability: (a) swelling and smearing of the borehole, possibly lowering the permeability values; (b) packer bypass by larger fractures; (c) test section lying in small but intact (without fractures) rock segment, possibly resulting in lower permeability values; and (d) test section lying right at the extensive fractures, possibly measuring higher permeability values. Once the anomalous measurement data were discarded, the numerical model results could be seen to match the remaining field permeability measurement data reasonably well.
Methane release in drainage holes ahead of coal face
超前工作面排放口瓦斯排放
Journal of Mining Science, January 2014, Volume 50, Issue 1, pp 60-64
Abstract: The authors have revealed features of local minimum methane concentration in drainage holes and causes of the methane concentration zonality. The offered hypothesis on methane release in drainage holes accounts for zonal disintegration of rock mass around an excavation.
