Research on influence of pore structure connectivity of low gas permeability on coal seam permeability

YAN Min; ZHANG Binbin; LI Jinliang; ZHANG Kunyin; ZHOU Ming; YAN Dongjie

Safety in Coal Mines > 2021 > 52(4): 31-38.

YAN Min, ZHANG Binbin, LI Jinliang, ZHANG Kunyin, ZHOU Ming, YAN Dongjie. Research on influence of pore structure connectivity of low gas permeability on coal seam permeability[J]. Safety in Coal Mines, 2021, 52(4): 31-38.

Citation:

Research on influence of pore structure connectivity of low gas permeability on coal seam permeability

More Information

Published Date: April 19, 2021

Graphical Abstract

Abstract

Abstract

In order to study the pore structure characteristics and pore connectivity of low-permeability coal, low-field nuclear magnetic resonance technology was used to analyze the raw coal sample. The T2 curve of the coal sample under saturated water and residual water conditions was used to obtain the free fluid value, irreducible fluid value, effective porosity, pore size distribution, and permeability etc. A quantitative calculation model of pore connectivity was established on the basis of these works. The results showed that the porosity of the experimental coal sample was changing from 6.30% to 11.02%, and the pore size was distributed in three stages, the pore size was mainly concentrated in the 0 nm to 100 nm segment. The fissures and the pores which including macropore and medium ones were not developed. Adsorption pore was inversely proportional to porosity. Percolation pore was proportional to porosity. The pore connectivity of experimental coal sample was varying between 31.50% and 62.05%. The pore connectivity was affected by the pore size, and the pore connectivity rate of the experimental coal sample with a pore size below 100 nm was up to 58.45%. The connectivity rate of pores with pore size over 100 nm was above 94%. Pore connectivity has a good positive correlation with porosity, effective porosity, and permeability.
- low gas permeability coal,
- porous structure,
- pore connectivity,
- permeability,
- nuclear magnetic resonance

FullText(HTML)

References (18)

References

[1]	谢和平,吴立新,郑德志.2025年中国能源消费及煤炭需求预测[J].煤炭学报,2019,44(7):1949-1960. XIE Heping, WU Lixin, ZHENG Dezhi. Prediction on the energy consumption and coal demand of China in 2025[J]. Journal of China Coal Society, 2019, 44(7): 1949-1960.
[2]	谢和平,周宏伟,薛东杰,等.煤炭深部开采与极限开采深度的研究与思考[J].煤炭学报,2012,37(4):535-542. XIE Heping, ZHOU Hongwei, XUE Dongjie, et al. Research and consideration on deep coal mining and critical mining depth[J]. Journal of China Coal Society, 2012, 37(4): 535-542.
[3]	康永尚,孙良忠,张兵,等.中国煤储层渗透率分级方案探讨[J].煤炭学报,2017,42(S1):186-194. KANG Yongshang, SUN Liangzhong, ZHANG Bing, et al. Discussion on classification of coalbed reservoir permeability in China[J]. Journal of China Coal Society, 2017, 42(S1): 186-194.
[4]	聂百胜,伦嘉云,王科迪,等.煤储层纳米孔隙结构及其瓦斯扩散特征[J].地球科学,2018,43(5):397. NIE Baisheng, LUN Jiayun, WANG Kedi, et al. Characteristics of nanometer pore structure of coal reservoir[J]. Earth Science, 2018, 43(5): 397.
[5]	潘结南,张召召,李猛,等.煤的多尺度孔隙结构特征及其对渗透率的影响[J].天然气工业,2019,39(1):64-73. PAN Jienan, ZHANG Zhaozhao, LI Meng, et al. Characteristics of multi-scale pore structure of coal and its influence on permeability[J]. Natural Gas Industry, 2019, 39(1): 64-73.
[6]	王刚,秦相杰,江成浩,等.温度作用下CT三维重建煤体微观结构的渗流和变形模拟[J].岩土力学,2020(5):1-11. WANG Gang, QIN Xiangjie, JIANG Chenghao, et al. Seepage and deformation simulation of CT3D reconstruction of coal microstructure under temperature[J]. Rock and Soil Mechanics, 2020(5): 1-11.
[7]	Xiaowei Hou, Yanming Zhu, Yang Wang, et al. Experimental study of the interplay between pore system and permeability using pore compressibility for high rank coal reservoirs[J]. Fuel, 2019, 254: 115712.
[8]	叶桢妮,侯恩科,段中会,等.不同煤体结构煤的孔隙裂隙分形特征及其对渗透性的影响[J].煤田地质与勘探,2019,47(5):70-78. YE Zhenni, HOU Enke, DUAN Zhonghui, et al. Fractal characteristics of pores and microfractures of coals with different structure and their effect on permeability[J]. Coal Geology & Exploration, 2019, 47(5): 70-78.
[9]	ShuaiBing Song, JiangFeng Liu, DianSen Yang, et al. Pore structure characterization and permeability prediction of coal samples based on SEM images[J]. Journal of Natural Gas Science and Engineering, 2019, 67: 160-171.
[10]	刘永茜,侯金玲,张浪,等.孔隙结构控制下的煤体渗透实验研究[J].煤炭学报,2016,41(S2):434-440. LIU Yongqian, HOU Jinling, ZHANG Lang, et al. Permeability experiments of pore structure in coal matrix[J]. Journal of China Coal Society, 2016, 41(S2): 434-440.
[11]	Sijian Zheng, Yanbin Yao, Dameng Liu, et al. Characterizations of full-scale pore size distribution, porosity and permeability of coals: A novel methodology by nuclear magnetic resonance and fractal analysis theory[J]. International Journal of Coal Geology, 2018, 196: 148-158.
[12]	任会康,王安民,李昌峰,等.基于核磁共振技术的低阶煤储层孔隙特征研究[J].煤炭科学技术,2017,45(4):143-148. REN Huikang, WANG Anmin, LI Changfeng, et al.Study on porosity characteristics of low-rank coal reservoirs based on nuclear magnetic resonance technology[J]. Coal Science and Technology, 2017, 45(4): 143-148.
[13]	李杰林,周科平,张亚民,等.基于核磁共振技术的岩石孔隙结构冻融损伤试验研究[J].岩石力学与工程学报,2012(6):1208-1214. LI Jielin, ZHOU Keping, ZHANG Yamin, et al. Experimental study of rock porous structure damage characteristics under condition of freezing-thawing cycles based on nuclear magnetic resonance technique[J]. Chinese Journal of Rock Mechanics and Engineering, 2012(6): 1208-1214.
[14]	周科平,李杰林,许玉娟,等.基于核磁共振技术的岩石孔隙结构特征测定[J].中南大学学报(自然科学版),2012,43(12):4796-4800. ZHOU Keping, LI Jielin, XU Yujuan, et al. Measurement of rock pore structure based on NMR technology[J]. Journal of Central South University(Science and Technology), 2012, 43(12): 4796-4800.
[15]	B B 霍多特.煤与瓦斯突出[M].宋士钊,王佑安,译.北京:中国工业出版社,1966.
[16]	Yidong Cai, Dameng Liu, Zhejun Pan, et al. Petrophysical characterization of Chinese coal cores with heat treatment by nuclear magnetic resonance[J]. Fuel, 2013, 108(11): 292-302.
[17]	Kenyon W E, Day P I, Straley C, et al. A three-part study of NMR longitudinal relaxation properties of water-saturated sandstones[J]. SPE Formation Evaluation, 1988, 3(3): 622-636.
[18]	Yanbin Yao, Dameng Liu, Jungang Liu, et al. Assessing the water migration and permeability of large intact bituminous and anthracite coals using NMR relaxation spectrometry[J]. Transport in Porous Media, 2015, 107(2): 527-542.

[1]	LI Nana, LIU Huihu, SANG Shuxun. Comparative study on pore size distribution in coal based on mercury intrusion-low temperature liquid nitrogen combined pore and nuclear magnetic resonance analysis[J]. Safety in Coal Mines, 2024, 55(2): 1-9. DOI: 10.13347/j.cnki.mkaq.20230344
[2]	ZHANG Huifeng. Experimental study on effect of freezing time of liquid CO₂ on pore structure of coal[J]. Safety in Coal Mines, 2022, 53(5): 27-31.
[3]	YAO Junhui, CHEN Hui, GUAN Weiming, ZHANG Junhui. Effect of microwave heating on microstructure of sandstone in coal seam roof[J]. Safety in Coal Mines, 2022, 53(2): 80-85,92.
[4]	XU Yang, HUANG Hui, CHU Yapei, HE Miao, GAN Lijia. Research on evolution law of coal pore structure damage under the action of freeze-thaw[J]. Safety in Coal Mines, 2021, 52(10): 38-44.
[5]	CAO Yuzhao, HAO Huili, WANG Haichao, Jianati Yeerken, Wumuerjiang Dawulieti. Experimental study on effect of H₂S aqueous solution on permeability of low-rank coal[J]. Safety in Coal Mines, 2021, 52(9): 29-35.
[6]	HU Qiujia, LIU Shiqi, YAN Ling, WANG He, FANG Huihuang, ZHANG Qing, MAO Chonghao, JIA Huiming. Occurrence, Migration and Output Path of Gas and Water in Anthracite Coal in Fanzhuang and Zhengzhuang Blocks[J]. Safety in Coal Mines, 2020, 51(10): 218-222.
[7]	DU Xiaofang. Characteristics of Freeze-thaw Damage Evolution of Pore Structure in Backfill Material Based on NMR Technology[J]. Safety in Coal Mines, 2019, 50(9): 75-78.
[8]	DUAN Xinjun, WEN Zhihui. Experimental Study on Pore Characteristics of Fenton Modified Coal Samples Based on Nuclear Magnetic Resonance[J]. Safety in Coal Mines, 2018, 49(12): 17-20.
[9]	ZHANG Liang, REN Fenhua, HAN Meng, YANG Zhuang, SUN Yicheng, LIU Kang. Development and Damage of Cracks in Front of Granite Triaxial Compression Peak Based on Nuclear Magnetic Resonance[J]. Safety in Coal Mines, 2018, 49(9): 87-90,95.
[10]	XU Xiaomeng, MA Hongxing, TIAN Jianwei, WANG Jiajian, LI Guangyao. Study on Microscopic Pore Structures of Coal Based on Nuclear Magnetic Resonance Technology[J]. Safety in Coal Mines, 2017, 48(2): 1-4.

Cited By

Cited by

Periodical cited type(1)

李常虎，李征征，王群. 西南某水电站拱坝建基岩体缓倾结构面的连通率分析方法. 地质力学学报. 2022(06): 948-955 .

Other cited types(4)

Get Citation

XML

Article views (22) PDF downloads (0) Cited by(5)

Turn off MathJax

Article Contents

Abstract

References

Research on influence of pore structure connectivity of low gas permeability on coal seam permeability

Abstract

References

Related Articles

Cited by

Periodical cited type(1)

Other cited types(4)

Catalog

Research on influence of pore structure connectivity of low gas permeability on coal seam permeability

Abstract

References

Related Articles

Cited by

Periodical cited type(1)

Other cited types(4)

Catalog

Export File

Citation

Format

Content