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81.
定向羽状水平井是指通过定向井、多分支水平井技术,由地面垂直向下钻至造斜点后以中、小曲率半径侧斜钻进目的煤层主水平井,再从主井两侧不同位置水平侧钻分支井,进而形成像羽毛状的多分支水平井.这一技术是一项复杂的系统工程,目前在中国煤层气领域还处在研究和试验阶段,尚未形成一系列成熟的工艺与技术. 相似文献
82.
中国煤层气勘探开发进展综述 总被引:1,自引:0,他引:1
综述了中国煤层气勘探开发利用现状,尤其是“十五”期间中国煤层气取得的进展。总结了中国煤层气资源勘探开发成果:基础研究和应用研究齐头并进;勘探方向更加明确;煤层气勘探开发关键技术类型多样,试验推广应用范围扩大;十大重要勘探成果初露煤层气产业化曙光。国家级沁南潘河煤层气开发示范项目、晋城寺河煤层气开发项目、沁南枣园煤层气开发试验项目、阜新煤层气开发试验项目的建成和投产,标志着中国开始进入煤层气商业化开发阶段。 相似文献
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85.
Cleats and their relation to geologic lineaments and coalbed methane potential in Pennsylvanian coals in Indiana 总被引:2,自引:0,他引:2
Wilfrido Solano-Acosta Maria Mastalerz Arndt Schimmelmann 《International Journal of Coal Geology》2007,72(3-4):187-208
Cleats and fractures in Pennsylvanian coals in southwestern Indiana were described, statistically analyzed, and subsequently interpreted in terms of their origin, relation to geologic lineaments, and significance for coal permeability and coalbed gas generation and storage. These cleats can be interpreted as the result of superimposed endogenic and exogenic processes. Endogenic processes are associated with coalification (i.e., matrix dehydration and shrinkage), while exogenic processes are mainly associated with larger-scale phenomena, such as tectonic stress.At least two distinct generations of cleats were identified on the basis of field reconnaissance and microscopic study: a first generation of cleats that developed early on during coalification and a second generation that cuts through the previous one at an angle that mimics the orientation of the present-day stress field. The observed parallelism between early-formed cleats and mapped lineaments suggests a well-established tectonic control during early cleat formation. Authigenic minerals filling early cleats represent the vestiges of once open hydrologic regimes. The second generation of cleats is characterized by less prominent features (i.e., smaller apertures) with a much less pronounced occurrence of authigenic mineralization. Our findings suggest a multistage development of cleats that resulted from tectonic stress regimes that changed orientation during coalification and basin evolution.The coals studied are characterized by a macrocleat distribution similar to that of well-developed coalbed methane basins (e.g., Black Warrior Basin, Alabama). Scatter plots and regression analyses of meso- and microcleats reveal a power-law distribution between spacing and cleat aperture. The same distribution was observed for fractures at microscopic scale. Our observations suggest that microcleats enhance permeability by providing additional paths for migration of gas out of the coal matrix, in addition to providing access for methanogenic bacteria.The abundance, distribution, and orientation of cleats control coal fabric and are crucial features in all stages of coalbed gas operations (i.e., exploration and production). Understanding coal fabric is important for coal gas exploration as it may be related to groundwater migration and the occurrence of methanogenic bacteria, prerequisite to biogenic gas accumulations. Likewise, the distribution of cleats in coal also determines pathways for migration and accumulation of thermogenic gas generated during coalification. 相似文献
86.
Underground coal mines have always had to control the presence of different gases in the mining environment. Among these gases, methane is the most important one, since it is inherent to coal. Despite of the technical developments in recent decades, methane hazards have not yet been fully avoided. This is partly due to the increasing depths of modern mines, where methane emissions are higher, and also to other mining-related circumstances, such as the increase in production rates and its consequences: difficulties in controlling the increasing methane levels, increasing mechanization, the use of explosives and not paying close attention to methane control systems.The main purposes of this paper are to establish site measurements using some critical parameters that are not part of the standard mining-control methods for risk assessment and to analyze the gas behavior of subvertical coal seams in deep mines in order to prevent gas incidents from occurring. The ultimate goal is the improvement in mining conditions and therefore in safety conditions.For this purpose, two different mines were instrumented for mine control and monitoring. Both mines belong to the Riosa–Olloniego coalfield, in the Asturias Central Basin, Spain and the areas instrumented are mined via subhorizontal sublevels at an actual depth of around 1000 m under the overburden of Mount Lusorio.During this research, a property favoring gas outbursts was site measured for the first time in an outburst-prone coal (8th Coalbed), gas pressure and its variations, which contributed to complete the data available from previous characterizations and to set some guidelines for assessing the potential outburst-prone areas. A gas-measurement-tube set has been designed for measuring gas pressure as well as its variation over time as a result of nearby workings and to calculate permeability.The paper establishes the effect of overlapping of works, but it also shows the efficacy of two preventive measures to be applied: high pressure water infusion and the exploitation of a protective coal seam (7th Coalbed), that must be mined preferably two complete sublevels before commencing the advance in the outburst-prone coalbed. Both measures constitute an improvement in the mining sequence and therefore in safety, and should be completed with a systematic measurement to control the risk: gas pressure in the 8th Coalbed in the area of influence of other workings, to establish the most suitable moment to renew the advance. Further researches could focus on ascertaining the permeability, not only in mined areas but also in areas of the mine that are still not affected by mining work and on tuning more finely the ranges of influence of overstress time and overlap distance of the workings of the 7th Coalbed in the 8th Coalbed. 相似文献
87.
中国城市固体废弃物甲烷排放研究 总被引:2,自引:0,他引:2
The greenhouse effect of methane (CH4) is only inferior to that of carbon dioxide (CO2). As an important anthropogenic emission source, the calculation of the emission amount of CH4 from waste treatment in landfills plays an important role in compiling greenhouse gases inventory and in estimating the climate change effects caused by increasing of greenhouse gases. Based on the previous work, and according to the sampling and analysis on municipal solid waste (MSW) in typical cities, the degradable organic carbon (DOC) percentile was identified in typical cities in recent years. According to the IPCC greenhouse gases inventory guideline and default method of CH4 emission from MSW landfills, and in light of MSW managing situation in different regions, the amount of CH4 emission was calculated. The results show that the amount of CH4 emission decreases geographically from east to west and it increases temporally from 1994 to 2004 in China. 相似文献
88.
REGULARITYANDESTIMATIONOFMETHANEEMISSIONFROMMARSHLANDINTHESANJIANGPLAIN①CuiBaoshan(崔保山)MaXuehui(马学慧)ChangchunInstituteofGeogr... 相似文献
89.
陈练武 《地球科学与环境学报》1998,20(1):33-35
探讨了煤层割理的成因、分类及主要影响因素,分析了韩城矿区主要煤层割理的发育特征及其对煤层气赋存和开发的控制作用。 相似文献
90.
鄂尔多斯盆地中部气田奥陶系风化壳气藏天然气来源及混源比计算 总被引:19,自引:4,他引:15
对鄂尔多斯盆地中部气田天然气碳同位素资料按不同地区、不同层位进行了分析,认为奥陶系风化壳气藏甲烷碳同位素值与石炭-二叠系气藏的接近,在平面上变化趋势相似,而与风化壳之下奥陶系自生自储的油型气相差较大。奥陶系风化壳气藏的来源是以石炭-二叠系煤成气为主,定量计算表明,在中部气田的大部分地区,石炭-二叠系来源气的比例大于70%。 相似文献