构造煤原生结构煤微孔特征的多重统计对比及其差异成因机制
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摘要
孔径小于2 nm的微孔孔隙控制着煤的吸附能力,开展构造煤与原生结构煤微孔特征的对比研究有助于厘清构造煤是否具有超强瓦斯吸附能力。为统计确证构造煤与原生结构煤孔径小于2 nm的微孔孔隙是否存在显著差异,判断造成微孔孔隙特征变化的主控因素并探讨其原因,对鹤壁六矿、平顶山八矿和淮南谢桥矿3组采自同一煤层共生的构造煤与原生结构煤煤样,采用CO2吸附法测定了孔径小于2 nm的微孔孔隙特征参数,并基于CART递归分割、LSD多重比较及多元方差分析等统计分析方法对构造煤与原生结构煤的微孔孔容进行了多重统计对比研究。结果表明:1)构造煤与原生结构煤孔径小于2 nm的微孔孔容没有显著差异;2)构造变形作用对孔径小于2nm微孔孔隙变化的影响远小于变质作用;3)构造煤的吸附能力不是构造煤发育煤层易突出的主要原因;4)煤类微晶结构参数的变化是煤微孔形成的主控因素。
This paper is to introduce a statistical investigation as to whether there exist significant differences in the characteristic features of micropore with their pore diameters less than 2 nanometers between the tectonically deformed and undeformed coal particles so as to find the dominant factors accounting for such differences. For the said purpose,we have managed to take the experimental measures of such micropore structures with the CO2 adsorption method. In doing so,we have chosen 3 groups of deformed and undeformed coal samples from the same coal seam of Hebi 6 thcoal mine,Pingdingshan No. 8 coal mine and Huainan Xieqiao coal mine,separately and isolatedly. And,then,the pore volume of each group coal samples was put into statistical procession and comparison. And,next,they were let to be partitioned by CART recursive partitioning algorithm to ascertain the boundaries of each peak on the pore volume curves so as for the pore volume of each sample groups and that of the peak value of each coal sample group to be compared via the least-significantdifference( LSD) method. Further multivariate analysis has been done by using the variance( MANOVA) to identify and determine whether the tectonic movement or the metamorphism serves as the dominant factor that results in the formation of the micropore in the coal body,which may help us to make a final analytic discussion over the potentially profound causes. The results of our analysis and discussion can be shown as follows:( 1) For the micropore with the pore diameter less than 2 nanometers,there may not exist any significant difference in the pore volume between the deformed and undeformed coal particles;( 2) It is metamorphism rather than the tectonic deformation that account for the difference in the micropore features;( 3) There ought to exist a little difference in the adsorption capacities between the deformed and undeformed coal seams,though the adsorption capacity may not be the principal reason for the outburst of the deformed coal seams;( 4)The regular changes of the microcrystalline parameters in the coal serve as the chief cause for the formation of micropore in the coal.In addition,with the increase of the coal particle ranks,the distance of the aromatic sheet in the crystal nucleus of the coal particles would become smaller with the increase of the packing degree and ductility of the coal particles. However,the increase of the stacking degree and ductility should be much greater than the decrease of the interlayer space,which may account for the principal cause that results in the more micropores.
This paper is to introduce a statistical investigation as to whether there exist significant differences in the characteristic features of micropore with their pore diameters less than 2 nanometers between the tectonically deformed and undeformed coal particles so as to find the dominant factors accounting for such differences. For the said purpose,we have managed to take the experimental measures of such micropore structures with the CO2 adsorption method. In doing so,we have chosen 3 groups of deformed and undeformed coal samples from the same coal seam of Hebi 6 thcoal mine,Pingdingshan No. 8 coal mine and Huainan Xieqiao coal mine,separately and isolatedly. And,then,the pore volume of each group coal samples was put into statistical procession and comparison. And,next,they were let to be partitioned by CART recursive partitioning algorithm to ascertain the boundaries of each peak on the pore volume curves so as for the pore volume of each sample groups and that of the peak value of each coal sample group to be compared via the least-significantdifference( LSD) method. Further multivariate analysis has been done by using the variance( MANOVA) to identify and determine whether the tectonic movement or the metamorphism serves as the dominant factor that results in the formation of the micropore in the coal body,which may help us to make a final analytic discussion over the potentially profound causes. The results of our analysis and discussion can be shown as follows:( 1) For the micropore with the pore diameter less than 2 nanometers,there may not exist any significant difference in the pore volume between the deformed and undeformed coal particles;( 2) It is metamorphism rather than the tectonic deformation that account for the difference in the micropore features;( 3) There ought to exist a little difference in the adsorption capacities between the deformed and undeformed coal seams,though the adsorption capacity may not be the principal reason for the outburst of the deformed coal seams;( 4)The regular changes of the microcrystalline parameters in the coal serve as the chief cause for the formation of micropore in the coal.In addition,with the increase of the coal particle ranks,the distance of the aromatic sheet in the crystal nucleus of the coal particles would become smaller with the increase of the packing degree and ductility of the coal particles. However,the increase of the stacking degree and ductility should be much greater than the decrease of the interlayer space,which may account for the principal cause that results in the more micropores.
引文
[1]YUAN Chongfu(袁崇孚).Tectonically deformed coal and coal-gas outburst[J].Coal Science and Technology(煤炭科学技术),1986(1):32-33.
[2]GRAY I.Reservoir engineering in coal seams[J].SPE Reservoir Engineering,1987,2(1):28-34.
[3]CLARKSON C R,BUSTIN R M.Variation in micropore capacity and size distribution with composition in bituminous coal of the Western Canadian sedimentary basin:implications for coalbed methane potential[J].Fuel,1996,75(13):1483-1498.
[4]CLARKSON C R,BUSTIN R M.The effect of pore structure and gas pressure upon the transport properties of coal:a laboratory and modeling study.1.Isotherms and pore volume distributions[J].Fuel,1999,78(11):1333-1344.
[5]LIU Yanwei(刘彦伟),LIU Mingju(刘明举).Effect of particle size on difference of gas desorption and diffusion between soft coal and hard coal[J].Journal of China Coal Society(煤炭学报),2015,40(3):579-587.
[6]HOU Quanlin(侯泉林),LI Xiaoshi(李小诗).The effect of tectonic deformation on gas outburst and excess coalbed methane[J].Physics(物理),2014,43(6):373-380.
[7]MENG Zhaoping(孟召平),LIU Shanshan(刘珊珊),WANG Baoyu(王保玉),et al.Adsorption capacity and its pore structure of coals with different coal body structure[J].Journal of China Coal Society(煤炭学报),2015,40(8):1865-1870.
[8]GU Yifan(顾熠凡),WANG Zhaofeng(王兆丰),QI Lingling(戚灵灵).Study on porous structure difference of soft coal and hard coal based on mercury intrusion method[J].Coal Science and Technology(煤炭科学技术),2016,44(4):64-67.
[9]FAN Junjia(范俊佳),JU Yiwen(琚宜文),HOU Quanlin(侯泉林),et al.Pore structure characteristics of dif ferent metamorphicdeformed coal reservoirs and its restriction on recovery of coalbed methane[J].Earth Science Frontiers(地学前缘),2010,17(5):325-335.
[10]ZHANG Hongri(张红日).Features of porosity of the structural coal—analysis of theⅠ3 andⅢ3 coal seams of Xiahuayuan colliery in Hebei Province[J].Jouranl of Shandong Institute of Mining Technology:Natural Science(山东科技大学学报:自然科学版),1999,18(1):12-16.
[11]JIANG Jiayu(姜家钰),LEI Dongji(雷东记),XIE Xiangxiang(谢向向),et al.Coupling features of the pore structure with gas of the deformed coals[J].Journal of Safety and Environment(安全与环境学报),2015,15(1):123-128.
[12]QU Zhenghui(屈争辉),JIANG Bo(姜波),LI Ming(李明),et al.Micropore properties and its origin of tectonically deformed coals[J].Journal of China Coal Society(煤炭学报),2015,40(5):1093-1102.
[13]LI Tengfei(李腾飞),TIAN Hui(田辉),CHEN Ji(陈吉),et al.The application of low pressure gas adsorption to the characterization of pore size distribution for shales:an example from southeastern Chongqing area[J].Natural Gas Geoscience(天然气地球科学),2015,26(9):1719-1728.
[14]LI Chunxin(李春鑫),LI Tianwei(李天伟).Decision support and analysis technique based on improved CART arithmetic of decision trees[J].Computer Science(计算机科学),2004,31(S1):44-46.
[15]MENG Xianhua(孟宪花).A study of some problems in multiple comparisons(多重比较中的一些问题研究)[D].Shanghai:East China Normal University,2009:37-39.
[16]YANG Quanhong(杨全红),ZHENG Jingtang(郑经堂),WANG Maozhang(王茂章),et al.Nano-space and surface micro-structures of microporous carbon[J].Chinese Journal of Materials Research(材料研究学报),2000,14(2):113-122.
[17]CHEN Changguo(陈昌国),ZHANG Daijun(张代钧),XIAN Xiaohong(鲜晓红),et al.The microcrystal structure and coalification degree of coal[J].Coal Conversion(煤炭转化),1997,20(1):45-49.
[2]GRAY I.Reservoir engineering in coal seams[J].SPE Reservoir Engineering,1987,2(1):28-34.
[3]CLARKSON C R,BUSTIN R M.Variation in micropore capacity and size distribution with composition in bituminous coal of the Western Canadian sedimentary basin:implications for coalbed methane potential[J].Fuel,1996,75(13):1483-1498.
[4]CLARKSON C R,BUSTIN R M.The effect of pore structure and gas pressure upon the transport properties of coal:a laboratory and modeling study.1.Isotherms and pore volume distributions[J].Fuel,1999,78(11):1333-1344.
[5]LIU Yanwei(刘彦伟),LIU Mingju(刘明举).Effect of particle size on difference of gas desorption and diffusion between soft coal and hard coal[J].Journal of China Coal Society(煤炭学报),2015,40(3):579-587.
[6]HOU Quanlin(侯泉林),LI Xiaoshi(李小诗).The effect of tectonic deformation on gas outburst and excess coalbed methane[J].Physics(物理),2014,43(6):373-380.
[7]MENG Zhaoping(孟召平),LIU Shanshan(刘珊珊),WANG Baoyu(王保玉),et al.Adsorption capacity and its pore structure of coals with different coal body structure[J].Journal of China Coal Society(煤炭学报),2015,40(8):1865-1870.
[8]GU Yifan(顾熠凡),WANG Zhaofeng(王兆丰),QI Lingling(戚灵灵).Study on porous structure difference of soft coal and hard coal based on mercury intrusion method[J].Coal Science and Technology(煤炭科学技术),2016,44(4):64-67.
[9]FAN Junjia(范俊佳),JU Yiwen(琚宜文),HOU Quanlin(侯泉林),et al.Pore structure characteristics of dif ferent metamorphicdeformed coal reservoirs and its restriction on recovery of coalbed methane[J].Earth Science Frontiers(地学前缘),2010,17(5):325-335.
[10]ZHANG Hongri(张红日).Features of porosity of the structural coal—analysis of theⅠ3 andⅢ3 coal seams of Xiahuayuan colliery in Hebei Province[J].Jouranl of Shandong Institute of Mining Technology:Natural Science(山东科技大学学报:自然科学版),1999,18(1):12-16.
[11]JIANG Jiayu(姜家钰),LEI Dongji(雷东记),XIE Xiangxiang(谢向向),et al.Coupling features of the pore structure with gas of the deformed coals[J].Journal of Safety and Environment(安全与环境学报),2015,15(1):123-128.
[12]QU Zhenghui(屈争辉),JIANG Bo(姜波),LI Ming(李明),et al.Micropore properties and its origin of tectonically deformed coals[J].Journal of China Coal Society(煤炭学报),2015,40(5):1093-1102.
[13]LI Tengfei(李腾飞),TIAN Hui(田辉),CHEN Ji(陈吉),et al.The application of low pressure gas adsorption to the characterization of pore size distribution for shales:an example from southeastern Chongqing area[J].Natural Gas Geoscience(天然气地球科学),2015,26(9):1719-1728.
[14]LI Chunxin(李春鑫),LI Tianwei(李天伟).Decision support and analysis technique based on improved CART arithmetic of decision trees[J].Computer Science(计算机科学),2004,31(S1):44-46.
[15]MENG Xianhua(孟宪花).A study of some problems in multiple comparisons(多重比较中的一些问题研究)[D].Shanghai:East China Normal University,2009:37-39.
[16]YANG Quanhong(杨全红),ZHENG Jingtang(郑经堂),WANG Maozhang(王茂章),et al.Nano-space and surface micro-structures of microporous carbon[J].Chinese Journal of Materials Research(材料研究学报),2000,14(2):113-122.
[17]CHEN Changguo(陈昌国),ZHANG Daijun(张代钧),XIAN Xiaohong(鲜晓红),et al.The microcrystal structure and coalification degree of coal[J].Coal Conversion(煤炭转化),1997,20(1):45-49.