By analyzing the characteristics and the production mechanism of rock burstthat goes with abnormal gas emission in deep coal seams,the essential method of eliminatingabnormal gas emission by eliminating the occurrence...By analyzing the characteristics and the production mechanism of rock burstthat goes with abnormal gas emission in deep coal seams,the essential method of eliminatingabnormal gas emission by eliminating the occurrence of rock burst or depressingthe magnitude of rock burst was considered.The No.237 working face was selected asthe typical working face contacting gas in deep mining;aimed at this working face,a systemof rock burst prediction and control for coal seam contacting gas in deep mining wasestablished.This system includes three parts:① regional prediction of rock burst hazardbefore mining,② local prediction of rock burst hazard during mining,and ③ rock burstcontrol.展开更多
To understand the natural gas characteristics of multi-thin coal seam,this study selected the desorbed gas of coal seams in different layers of Well A in the Wujiu depression,Hailar Basin in northeast Inner Mongolia.T...To understand the natural gas characteristics of multi-thin coal seam,this study selected the desorbed gas of coal seams in different layers of Well A in the Wujiu depression,Hailar Basin in northeast Inner Mongolia.The results show that the heavy hydrocarbon content of desorbed gas increases significantly with the increasing depth.Methane carbon(δ13C_(1))and ethane carbon(δ13C_(2))isotope values are vertically become heavier downwards,while the δ13 values did not change significantly.The kerogen is close to the III–II mixed type with the source rocks mainly deposited in a shore/shallow lake or braided-river delta front,and the gas produced has certain characteristics of oil associated gas.However,the characteristics of oil associated gas produced by the organic formed in the shallow-water environment(braided-river delta plain)are not obvious.The sandstone pore and fracture systems interbedded with multi-thin coal seam are well developed.And it is conducive to the migration of methanogenic micro-organisms to coal seams via groundwater,making it easier to produce biogenic gas under this geological condition.During the burial evolution of coal-bearing strata in the study area,when the burial depth reaches the maximum,there are significant differences in the paleotemperature experienced by different vertical coal seams,caused by a high-paleogeothermal gradient,increasing the δ13C_(2) of desorbed gas with increasing depth.The above research indicates that there is less biogenic gas in the multi-thin coal seams with relatively developed mudstone,and the multi-thin coal seams with relatively developed sandstones have obvious biogenic gas characteristics.Therefore,for the exploration and development of biogenic gas in low-rank multi-thin coal seams,it is necessary to give priority to the layer with high sandstone content.展开更多
基金Supported by the National Natural Science Foundation(Instrument)of China(50427401)the National High Technology Research and Development Program of China(2006AA06Z119)+1 种基金the National Key Technology R&D Program in 11th Five Years Plan of China(2007BA29B01)the New Century Excellent Talents in University(NCET-06-0477)
文摘By analyzing the characteristics and the production mechanism of rock burstthat goes with abnormal gas emission in deep coal seams,the essential method of eliminatingabnormal gas emission by eliminating the occurrence of rock burst or depressingthe magnitude of rock burst was considered.The No.237 working face was selected asthe typical working face contacting gas in deep mining;aimed at this working face,a systemof rock burst prediction and control for coal seam contacting gas in deep mining wasestablished.This system includes three parts:① regional prediction of rock burst hazardbefore mining,② local prediction of rock burst hazard during mining,and ③ rock burstcontrol.
基金We would like to thank the National Natural Science Foundation of China(Grant Nos.42130802,42002193,and 42002186)researchers Yanqiu Zhang,Wutao Hu,Haitao Lin,and Fengchun Li from Inner Mongolia Coal Geology Bureau for their help in sample acquisition.
文摘To understand the natural gas characteristics of multi-thin coal seam,this study selected the desorbed gas of coal seams in different layers of Well A in the Wujiu depression,Hailar Basin in northeast Inner Mongolia.The results show that the heavy hydrocarbon content of desorbed gas increases significantly with the increasing depth.Methane carbon(δ13C_(1))and ethane carbon(δ13C_(2))isotope values are vertically become heavier downwards,while the δ13 values did not change significantly.The kerogen is close to the III–II mixed type with the source rocks mainly deposited in a shore/shallow lake or braided-river delta front,and the gas produced has certain characteristics of oil associated gas.However,the characteristics of oil associated gas produced by the organic formed in the shallow-water environment(braided-river delta plain)are not obvious.The sandstone pore and fracture systems interbedded with multi-thin coal seam are well developed.And it is conducive to the migration of methanogenic micro-organisms to coal seams via groundwater,making it easier to produce biogenic gas under this geological condition.During the burial evolution of coal-bearing strata in the study area,when the burial depth reaches the maximum,there are significant differences in the paleotemperature experienced by different vertical coal seams,caused by a high-paleogeothermal gradient,increasing the δ13C_(2) of desorbed gas with increasing depth.The above research indicates that there is less biogenic gas in the multi-thin coal seams with relatively developed mudstone,and the multi-thin coal seams with relatively developed sandstones have obvious biogenic gas characteristics.Therefore,for the exploration and development of biogenic gas in low-rank multi-thin coal seams,it is necessary to give priority to the layer with high sandstone content.
