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891.
892.
893.
阳泉矿区3#煤煤层气解吸特性的研究 总被引:1,自引:0,他引:1
实验测定了阳泉矿区3#煤煤层气的解吸特性。利用煤粒中吸附煤层气扩散微分方程式计算出煤层气的解吸时间,并用作图法确定出3#煤煤层气的解吸时间,为阳泉矿区3#煤煤层气的开发和利用提供了重要的参数。 相似文献
894.
In the offshore part of Beaufort–Mackenzie Basin depth of methane hydrate stability reaches more than 1.5 km. However, there are areas in the western part of the basin where there are no conditions of methane hydrate stability. Construction of the first contour maps displaying thickness of hydrate stability zones as well as hydrate stability zone thicknesses below permafrost in the offshore area, shows that these zones can reach 1200 m and 900 m, respectively. Depth to the base of ice-bearing relict permafrost under the sea (depth of the –1°C isotherm-ice-bearing permafrost base) and regional variations of geothermal gradient are the main controlling factors. Hydrostatic pressures in the upper 1500 m are the rule. History of methane hydrate stability zone is related mainly to the history of permafrost and it reached maximum depth in early Holocene. More recently, the permafrost and hydrate zone is diminishing because of sea transgression. Reevaluation of the location of possible gas hydrate occurrences is done from the analysis of well logs and other indicators in conjunction with knowledge of the hydrate stability zone. In the offshore Beaufort–Mackenzie Basin, methane hydrate occurs in 21 wells. Nine of these locations coincides with underlying conventional hydrocarbon occurrences. Previous analyses place some of the hydrate occurrences at greater depths than proposed for the methane hydrate-stability zone described in this study. Interpretation of geological cross sections and maps of geological sequences reveals that hydrates are occurring in the Iperk–Kugmallit sequence. Hydrate–gas contact zones, however, are possible in numerous situations. As there are no significant geological seals in the deeper part of the offshore basin (all hydrates are within Iperk), it is suggested that overlying permafrost and hydrate stability zone acted as the only trap for upward migrating gas during the last tens of thousand of years (i.e., Sangamonian to Holocene). 相似文献
895.
煤层气含量测试中的有关问题 总被引:1,自引:0,他引:1
为完善煤层气含量测试技术,笔者以美国GRI气含量测试指南为基础,根据我国煤层气勘探开发中诸多试验井的解吸试验结果,分析了测试环节的最佳实施尺度,探讨了各测试参数间的关系,对煤层气含量测试技术提出了新的认识。 相似文献
896.
The paper deals with the coalbed methane gas-bearing characteristics such as the gas content, theoretical gas saturation, gas concentration and abundance, as well as coal reservoir characteristics such as the adsorption, desorption and permeability of China's coal reservoirs. The paper also introduces the resources of coalbed methane with a gas content ≥4 m3/t and their distribution in China. 相似文献
897.
煤层甲烷碳同位素在煤层气勘探中的地质意义--以沁水盆地为例 总被引:30,自引:2,他引:28
根据沁水煤层气甲烷碳同位素的组成与分布特征,从煤层甲烷碳同位素在煤层气解吸-扩散-运移中的分馏效应,结合水文地质条件和构造条件,讨论了煤层甲烷碳同位素在煤层气勘探中的地质意义,认为沁水煤层气δ13C1值不仅总体上较高,而且随埋深增大而增高,说明沁水煤层气存在因煤层抬升而卸压所导致的煤层气解吸-扩散-运移效应,从而形成了该区甲烷碳同位素在平面上的分带现象。 相似文献
898.
土地利用方式对白浆土氧化甲烷的影响 总被引:3,自引:1,他引:2
白浆土在不同土地利用方式下CH4氧化潜力存在显著差异。天然草甸表层土氧化大气CH4的潜力最大,如果被开垦成人工林、旱田和水田,则氧化潜力分别降低64%、98%和117%。土壤透气性下降,甲烷氧化细菌数量减少以及活性降低,可能是土地利用方式改变后白浆土氧化CH4潜力下降的主要原因。白浆土氧化大气CH4潜力具有明显的垂直分异:草甸和林地土壤氧化大气CH4的潜力随着土壤深度的增加而减小;旱田土壤中耕作层下残存的有机质含量较高的层次仍保留了较强的氧化大气CH4潜力,氧化CH4速率是耕作层的13倍;即使是在大气中培养,水田土壤整个剖面仍排放CH4,最低层CH4排放率最小。供试白浆土氧化大气CH4速率与土壤有机碳、碱解氮和全氮含量显著正相关,与pH和土壤含水量(%WHC)负相关。在一定的温度和水分条件下,土壤有机碳含量是决定白浆土氧化大气CH4速率的一个最重要因素。 相似文献
899.
Gas hydrates-the firm crystal connections formed water (water, ice, water vapor) and low-molecular waterproof natural gases (mainly methane) whose crystal structure effectively compresses gas: each cubic meter of hydrate can yield over 160 m3 of methane.In present time exploitation of the Messoyahsk (Russia) and Mallik (Canada) deposits of gas hydrates in is conducted actively. The further perfection of prospecting methods in the field of studying gas hydrates containing sediments in round extent depends on improvement of geophysical and well test research, among which native-state core drilling is one of the major. Sampling native-state core from gas hydrates sediments keeping not only original composition, but structural-textural features of their construction.Despite of appeal of use gas hydrates as the perspective and ecologically pure fuel possessing huge resources, investigation and development of their deposits can lead to a number of the negative consequences connected with arising hazards for maintenance of their technical and ecological safety of carrying out. Scales of arising problems can change from local up to regional and even global. 相似文献
900.