In-situ gas contents of a multi-section coal seam in Sydney basin for coal and gas outburst management

International Journal of Coal Science & Technology

Research

Zhongbei Li¹  Itmam Abedin¹  Ming Qiao¹  Ting Ren²  Jessica Juric³  Mike Wang³  Dennis Black³ 

[1] School of Civil, Mining, Environmental and Architectural Engineering, University of Wollongong, 2522, Wollongong, NSW, Australia;School of Civil, Mining, Environmental and Architectural Engineering, University of Wollongong, 2522, Wollongong, NSW, Australia;School of Safety Engineering, China University of Mining and Technology, 221116, Xuzhou, China;South32 – Illawarra Metallurgical Coal, 2526, Wollongong, NSW, Australia;

关键词: In-situ coal seam gas content;    Direct desorption method;    Gas component;    Sorption capacity;    Coal and gas outburst;   

DOI  :  10.1007/s40789-023-00614-4

 received in 2023-05-30, accepted in 2023-07-28,  发布年份 2023

来源: Springer

【 摘 要 】

The gas content is crucial for evaluating coal and gas outburst potential in underground coal mining. This study focuses on investigating the in-situ coal seam gas content and gas sorption capacity in a representative coal seam with multiple sections (A1, A2, and A3) in the Sydney basin, where the CO2 composition exceeds 90%. The fast direct desorption method and associated devices were described in detail and employed to measure the in-situ gas components (Q1, Q2, and Q3) of the coal seam. The results show that in-situ total gas content (QT) ranges from 9.48 m3/t for the A2 section to 14.80 m3/t for the A3 section, surpassing the Level 2 outburst threshold limit value, thereby necessitating gas drainage measures. Among the gas components, Q2 demonstrates the highest contribution to QT, ranging between 55% and 70%. Furthermore, high-pressure isothermal gas sorption experiments were conducted on coal samples from each seam section to explore their gas sorption capacity. The Langmuir model accurately characterizes CO2 sorption behavior, with fit coefficients (R2) greater than 0.99. Strong positive correlations are observed between in-situ gas content and Langmuir volume, as well as between residual gas content (Q3) and sorption hysteresis. Notably, the A3 seam section is proved to have a higher outburst propensity due to its higher Q1 and Q2 gas contents, lower sorption hysteresis, and reduced coal toughness f value. The insights derived from the study can contribute to the development of effective gas management strategies and enhance the safety and efficiency of coal mining operations.

【 授权许可】

CC BY   
© China Coal Research Institute 2023

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