Effects of caprock sealing capacities on coalbed methane preservation: Experimental investigation and case study

IMR OpenIR

	Effects of caprock sealing capacities on coalbed methane preservation: Experimental investigation and case study
其他题名	Effects of caprock sealing capacities on coalbed methane preservation: Experimental investigation and case study
	Tian Fuchao 1; Liang Yuntao 1; Wang Deming 2; Jin Kan 1
	2019
发表期刊	JOURNAL OF CENTRAL SOUTH UNIVERSITY
ISSN	2095-2899
卷号	26 期号:4 页码:925-937
摘要	Caprocks play an important role in the trapping of coalbed methane (CBM) reservoirs. To study the sealing capacities of caprocks, five samples with different lithologies of Neogene clayrock, Paleogene redbeds, Permian sandstone, Permian mudstone and Permian siltstone were collected and tested using experimental methods of microstructure observation, pore structure measurement and diffusion properties determination. Results indicate that with denser structures, lower porosities, much more developed micropores/transition pores and higher pore/throat ratios, mudstone and siltstone have the more ideal sealing capacities for CBM preservation when comparing to other kinds of caprocks; the methane diffusion coefficients of mudstone/siltstone are about 6 times higher than sandstone and almost 90 times higher than clayrock/redbeds. To further estimate the CBM escape through caprocks, a one-dimensional CBM diffusion model is derived. Modeling calculation result demonstrates that under the same thickness, the CBM sealing abilities of mudstone/siltstone are almost 100 times higher than those of clayrock/redbeds, and nearly 17 times higher than sandstone, which indicates that the coal seam below caprocks like clayrock, redbeds or sandstone may suffer stronger CBM diffusion effect than that below mudstone or siltstone. Such conclusion is verified by the case study from III3 District, Xutuan Colliery, where the coal seam capped by Paleogene redbeds has a much lower CBM content than that capped by the Permian strata like mudstone, siltstone and sandstone.
其他摘要	Caprocks play an important role in the trapping of coalbed methane (CBM) reservoirs. To study the sealing capacities of caprocks, five samples with different lithologies of Neogene clayrock, Paleogene redbeds, Permian sandstone, Permian mudstone and Permian siltstone were collected and tested using experimental methods of microstructure observation, pore structure measurement and diffusion properties determination. Results indicate that with denser structures, lower porosities, much more developed micropores/transition pores and higher pore/throat ratios, mudstone and siltstone have the more ideal sealing capacities for CBM preservation when comparing to other kinds of caprocks; the methane diffusion coefficients of mudstone/siltstone are about 6 times higher than sandstone and almost 90 times higher than clayrock/redbeds. To further estimate the CBM escape through caprocks, a one-dimensional CBM diffusion model is derived. Modeling calculation result demonstrates that under the same thickness, the CBM sealing abilities of mudstone/siltstone are almost 100 times higher than those of clayrock/redbeds, and nearly 17 times higher than sandstone, which indicates that the coal seam below caprocks like clayrock, redbeds or sandstone may suffer stronger CBM diffusion effect than that below mudstone or siltstone. Such conclusion is verified by the case study from III3 District, Xutuan Colliery, where the coal seam capped by Paleogene redbeds has a much lower CBM content than that capped by the Permian strata like mudstone, siltstone and sandstone.
关键词	ORDOS BASIN COALFIELD GAS DIFFUSION SYSTEM AREA caprock sealing capacity coalbed methane preservation
收录类别	CSCD
语种	英语
资助项目	[National Key Research and Development Plan, China] ; [National Natural Science Foundation of China]
CSCD记录号	CSCD:6574326
引用统计	被引频次：1[CSCD] [CSCD记录]
文献类型	期刊论文
条目标识符	http://ir.imr.ac.cn/handle/321006/151900
专题	中国科学院金属研究所
作者单位	1.China University Min & Technol, Sch Safety Engn, Xuzhou 221116, Jiangsu, Peoples R China 2.中国科学院金属研究所
推荐引用方式 GB/T 7714	Tian Fuchao,Liang Yuntao,Wang Deming,et al. Effects of caprock sealing capacities on coalbed methane preservation: Experimental investigation and case study[J]. JOURNAL OF CENTRAL SOUTH UNIVERSITY,2019,26(4):925-937.
APA	Tian Fuchao,Liang Yuntao,Wang Deming,&Jin Kan.(2019).Effects of caprock sealing capacities on coalbed methane preservation: Experimental investigation and case study.JOURNAL OF CENTRAL SOUTH UNIVERSITY,26(4),925-937.
MLA	Tian Fuchao,et al."Effects of caprock sealing capacities on coalbed methane preservation: Experimental investigation and case study".JOURNAL OF CENTRAL SOUTH UNIVERSITY 26.4(2019):925-937.