Article
Energy & Fuels
Yubing Liu, Zuxun Zhang, Bozhi Deng, Minghui Li
Summary: Outbursts are the predominant natural hazards in Chinese underground coal mines. Extracting high content gas within coal seams is an effective way to reduce the risk of triggering outbursts. However, conventional gas drainage may fail due to the low permeability of coal seams at greater depths. This study proposes the use of liquid carbon dioxide fracturing to enhance gas drainage efficiency in a Chinese coal mine with low permeability coal seams. The results suggest that the application of liquid carbon dioxide fracturing is effective for gas control and hazards prevention in underground coal mines.
ENERGY SOURCES PART A-RECOVERY UTILIZATION AND ENVIRONMENTAL EFFECTS
(2023)
Article
Geosciences, Multidisciplinary
Junwei Yang, Xigui Zheng, Chengwei Liu, Wenjie Zhai, Hongyang Liu, Peng Zhang
Summary: This study applies the deep-hole pre-split blasting method to improve the gas extraction efficiency in the Wulunshan Coal Mine in Guizhou, where the coal seam has low permeability and conventional boreholes have low gas extraction rates. The study comprehensively explains the process of using the deep-hole pre-split blasting method to improve gas extraction efficiency and proposes a numerical simulation method. The results demonstrate that the blasting and permeability enhancement technique can effectively improve gas extraction efficiency in coal seams with high gas content and low permeability.
FRONTIERS IN EARTH SCIENCE
(2022)
Article
Geosciences, Multidisciplinary
Chenghang Fu, Heping Xie, Mingzhong Gao, Fei Wang, Jing Xie, Junjun Liu, Bengao Yang, Ruifeng Tang
Summary: The study revealed that coal in the fracture zone is most strongly affected by roadway excavation, forming effective permeability; coal in the disturbance zone is less affected and forms effective permeability after peak strength; coal in the original rock stress zone is only influenced by coal mining, with the lowest permeability.
GEOMATICS NATURAL HAZARDS & RISK
(2021)
Article
Geosciences, Multidisciplinary
Zhiheng Cheng, Hui Pan, Quanle Zou, Zhenhua Li, Liang Chen, Jialin Cao, Kun Zhang, Yongguo Cui
Summary: With the increasing demand for coal resources, coal has been mined in deep coal seams, leading to great risks of coal and gas outburst. Protective coal seam mining, as a safe and effective method for gas control, has been widely used. This study investigated stress-seepage coupling laws and permeability characteristics of a protected coal seam during the process of protective coal seam mining.
NATURAL RESOURCES RESEARCH
(2021)
Article
Geochemistry & Geophysics
Zhonghua Wang, Jianjun Cao, Jun Liu, Chengcheng Li
Summary: This study aims to address the issue of permeability enhancement in deep coal roadway strip and proposes a pressure relief roadway permeability enhancement model, which is verified through experiments, theoretical calculations, and field tests. The results show that unloading gas-containing coal can effectively enhance the permeability. Theoretical calculations and field tests provide insights into the optimal location for the pressure relief roadway and the width variations of the permeability enhancement zone.
Article
Green & Sustainable Science & Technology
Feng Zhang
Summary: The geological structures of coal fields in China are complex. With an increase in mining depth, the coal seams exhibit high gas and low permeability characteristics, which intensify the potential for coal and gas outbursts during mining. Gas drainage is a primary measure used to prevent and control gas disasters, and improving coal seam permeability is crucial. This study investigated the technology of liquid CO2 phase-transition fracturing in coal seams. Field tests at Baode Coal Mine showed positive results, with a significant increase in drainage effect, gas-drainage concentration, and permeability coefficient.
Article
Energy & Fuels
Haijun Guo, Hanlu Tang, Yuchen Wu, Kai Wang, Chao Xu
Summary: Coal is a complex dual-porosity porous medium composed of fractures and coal matrices. The gas seepage characteristics in coals are closely related to the coal matrix-fracture structures and can be simplified to equivalent scale characteristics. A simplified permeability evolution model and a method for measuring permeability in coal seams were proposed, enriching the theory of gas seepage and laying a foundation for studying the evolution mechanism of coal permeability during plastic deformation.
Article
Engineering, Environmental
Feng Gao, Leihu Tang, Chun Yang, Panlei Yang, Xin Xiong, Wenfeng Wang
Summary: The charge structure in the cutting area has significant engineering significance in tunneling practices with soft and broken surrounding rocks. The investigation of the effect of charge structure on blasting performance showed that using an air deck at the blasthole bottom effectively weakened damage and reduced cleaning time for loose rocks. Numerical and field experimental results were consistent in demonstrating the advantages of using an air deck in roadway excavation.
BULLETIN OF ENGINEERING GEOLOGY AND THE ENVIRONMENT
(2023)
Article
Environmental Sciences
Wei Tang, Cheng Zhai, Xu Yu, Jizhao Xu, Yong Sun, Yuzhou Cong, Yangfeng Zheng, Yujie Li
Summary: This paper analyzes the influence of sudden changes in coal property on stress transmission, coal deformation, energy accumulation, and plastic damage during roadway excavation in a geological structure using numerical methods. It is found that the geological interface between soft coal and hard coal plays a role in stress transfer and leads to the occurrence of tectonic stress. The study suggests that controlling the tunneling speed and reinforcing the geological anomaly area through pre-grouting are effective methods to improve the safety of roadway excavation.
ENVIRONMENTAL EARTH SCIENCES
(2022)
Article
Engineering, Geological
Xianfeng Liu, Baisheng Nie, Kunyong Guo, Chengpeng Zhang, Zepeng Wang, Longkang Wang
Summary: The liquid carbon dioxide phase change fracturing technology can effectively increase coal permeability, with the impact decreasing as the distance from the fracturing borehole increases. The influence of LCPCF on coal can be divided into three stages based on distance, with the greatest impact observed within 1.0 m and diminishing effects at distances greater than 6.0 m.
ENGINEERING GEOLOGY
(2021)
Article
Energy & Fuels
Zhenbao Li, Gaoming Wei, Rui Liang, Pengpeng Shi, Hu Wen, Wenhai Zhou
Summary: The study introduces an enhanced coalbed methane (ECBM) technology based on liquid carbon dioxide, which significantly improves methane drainage efficiency. Through experiments and theoretical deductions, the feasibility and recovery mechanisms of the technology were demonstrated.
Article
Engineering, Environmental
Wei Yang, Wenyuan Wang, Ru Jia, Gabriel Walton, Sankhaneel Sinha, Qinghe Chen, Baiquan Lin, Xiangdong Jiao
Summary: This paper systematically investigates the effects of different parameters on de-stress blasting performance. The study finds that filling the blast hole with water greatly improves blasting power and reduces blast wave transmission. Forward blasting enhances the transmission of the blasting wave deeper into the coal seam and increases the length of the stress relief zone in front of the coal face.
BULLETIN OF ENGINEERING GEOLOGY AND THE ENVIRONMENT
(2023)
Article
Construction & Building Technology
Hao Zhang, Tingchun Li, Shuai Wu, Xiantang Zhang, Wenle Gao, Qipeng Shi
Summary: This paper studied an innovative cut blasting technology based on cavity cutting and fragment throwing (CCFT) and designed a parallel cut with double fragment-throwing holes for rock roadway excavation. Through SPH-FEM modeling and geological analysis, the effectiveness of CCFT technique in improving face advance, protecting surrounding rock, and controlling blasting vibration was verified.
TUNNELLING AND UNDERGROUND SPACE TECHNOLOGY
(2022)
Article
Chemistry, Multidisciplinary
Tatiana Shilova, Sergey Serdyukov
Summary: The study predicted the permeability of gas-bearing coking coals in the Leninsky area of the Kuznetsk coal basin. Laboratory studies showed that as confining pressure increased, coal permeability decreased, and as depth increased, permeability decreased by 61-82%. These findings can be useful for designing industrial works for coal methane extraction in the region.
APPLIED SCIENCES-BASEL
(2021)
Article
Geosciences, Multidisciplinary
Weihua Song, Huice Jiao, Yingwei Wang
Summary: The crack closure induced by high-pressure air blasting in impact coal seams has a significant impact on gas drainage efficiency. The length of the crack closure was calculated and analyzed using energy and elastic theories, determining it to be 3.8 m from the blasting hole. Field experiments in a Chinese coal mine showed that crack closure led to a decreased gas emission amplitude in the closure region. The theoretical calculations were consistent with the field test results, providing a valuable reference for the arrangement of gas drainage boreholes.
FRONTIERS IN EARTH SCIENCE
(2023)
