Article
Geochemistry & Geophysics
Yihui Niu, Zuoming Xu, Wenhe Wang, Xiaofei Jing, Hongfu Mi, Zhen Zhong
Summary: Hole accidents and borehole collapse hinder efficient gas drainage from outburst-prone soft coal seams in China. This study tested a suspension-aided debris disposal technology using existing suspending agents to address problems such as residual drilling debris and low utilization of drill holes. The testing showed that the suspension method effectively discharged debris, rinsed drill holes, prevented debris from blocking coal seams, and improved gas extraction, resulting in increased gas production and concentration.
Review
Chemistry, Multidisciplinary
Meng Wu, Yong Qin, Yuanyuan Zhang, Shifei Zhu, Guchun Zhang, Fengjuan Lan, Xuejuan Song, Lele Feng, Yunhu Qin
Summary: This study examines the importance of geological CO2 sequestration in coal seams for coalbed methane development and greenhouse gas mitigation. Suitable geological conditions for CO2 sequestration include specific burial depths, permeability, caprock and floor strata characteristics, and coal type. Geological structures, shallow freshwater layers, and complex hydrological conditions should be avoided. The engineering conditions of temperature, pressure, and storage time are also important considerations. Feasibility evaluation of CO2 geological storage in coal seams requires a comprehensive understanding of coalfield geological factors. Site selection evaluation integrating principles feasibility, injection controllability, sequestration security, and development economy can optimize the sequestration area and provide rational CO2 geological storage layout recommendations.
Article
Energy & Fuels
Chenxu Luo, Junbei Qiao, Jiawei Zhou, Zhijia Sun, Jun Cao
Summary: This paper conducted experiments and established a mechanical model for the cutting of coal and rock by pick, providing a basis for further research.
Article
Multidisciplinary Sciences
Yu Xiong, Dezhong Kong, Zhijie Wen, Guiyi Wu, Qinzhi Liu
Summary: This study investigates the strength characteristics of coal faces under repeated mining in close coal seams through coal sample mechanics tests and similar simulation experiments. The research also explores the development of roof structures and surrounding rock cracks, and establishes a mechanics model to analyze the influence of multiple roof structural instabilities on coal face stability. Numerical simulation is used to verify the experimental and theoretical analysis results. The study finds that repeated mining leads to increased cracks in coal faces and reduces the strength of the coal body, increasing the risk of coal face failure.
SCIENTIFIC REPORTS
(2022)
Article
Construction & Building Technology
Yao-bin Li, Cai-Hao Yue, Xin Guo
Summary: Gas disasters have been adversely affecting coal mine safety. Optimizing gas extraction methods can improve efficiency and reduce risks. Through theoretical and numerical simulations, as well as field measurements, it has been found that the extraction effect of upper and lower cross strata boreholes is better, effectively eliminating the risk of coal seam outburst.
ADVANCES IN CIVIL ENGINEERING
(2022)
Article
Energy & Fuels
Shuyin Jiang, Gangwei Fan, Qizhen Li, Shizhong Zhang, Liang Chen
Summary: This study introduces a new method for optimizing customized shortwall mining parameters in deep extra-thick coal seams, aiming to achieve maximum coal recovery while ensuring surface deformation and coal pillar stability. Through case study and simulations, the optimal mining scheme with a mining height of 10m, mining width of 100m, and coal pillar width of 122m was determined, achieving a maximum coal recovery rate of 45% with stable coal pillars and acceptable surface deformation.
Article
Engineering, Environmental
Devi Prasad Mishra, Suraj Kumar Verma, Ram Madhab Bhattacharjee, Rajeev Upadhyay, Patitapaban Sahu
Summary: This study comprehensively assesses the geological and microstructural characteristics of two gassy coal seams in the Moonidih colliery. It found that the XV seam is more suitable for methane drainage due to its favorable properties.
BULLETIN OF ENGINEERING GEOLOGY AND THE ENVIRONMENT
(2023)
Article
Computer Science, Information Systems
Yang Zhou, Xin Chen, Min Wu, Weihua Cao
Summary: Geological drilling is an important means for exploring the Earth, but it faces challenges of low efficiency, safety concerns, and difficulty in predicting drilling states. This study proposes a novel optimization method that identifies working conditions, refines adjustment ranges, constructs reliable models, and solves a two-objective problem using an advanced algorithm. The effectiveness and practicability of the developed method are verified through various experiments and comparisons.
INFORMATION SCIENCES
(2023)
Article
Mining & Mineral Processing
Yang Li, Yuqi Ren, Syd S. Peng, Haozhou Cheng, Nan Wang, Junbo Luo
Summary: By using ZTR12 geological penetration radar (GPR) survey combined with borehole observations, the study measured the overburden caving due to mining of five coal seams, and found the periodic triangular caved characteristic in the overburden caving pattern.
INTERNATIONAL JOURNAL OF MINING SCIENCE AND TECHNOLOGY
(2021)
Article
Energy & Fuels
He Jiangfu, He Wenchao, Zhang Chengpeng, Sun Zhongguang, Sun Xiaoyi
Summary: This study numerically investigates the stress distribution and deformation failure level of gas drainage boreholes in deep soft coal seams. The simulation results show that the occurrence of vertical stress peak and position is influenced by geo-stress, compressive strength of the coal mass, and gas pressure of the coal, leading to displacement and deformation of the borehole wall. Additionally, the study finds that increasing the compressive strength can decrease the displacement and deformation of the borehole wall, while changing the borehole diameter does not have a significant impact on the stress and deformation failure of the borehole. These findings provide theoretical support for addressing stuck and collapse issues during drilling in deep and soft coal seams, and also demonstrate the positive influence of long and large inseam boreholes on gas drainage in highly gassy coal mines.
GEOMECHANICS AND GEOPHYSICS FOR GEO-ENERGY AND GEO-RESOURCES
(2022)
Article
Energy & Fuels
Guangfu Zhang, Shiming He, Ming Tang, Linghao Kong
Summary: This study investigates the mechanisms of wellbore instability and anticollapse countermeasures in the deep coal seam of the Dibei area in the Tarim basin, China. The microstructure and physical and chemical properties of coal and rock are studied to analyze instability mechanism. Orthogonal cleat model and 3 Dimension Distinct Element Code (3DEC) model are proposed to calculate the collapse pressure of the coal seam. A method for optimizing well trajectory based on wellbore stability is also proposed. An anti-collapse drilling fluid for coal seams is designed and applied in the field by optimizing plugging material. The findings of this study can help for better understanding of wellbore instability mechanism and countermeasures in coal seam and are useful for the safe and efficient development of the coal seams in the Dibei area.
JOURNAL OF PETROLEUM EXPLORATION AND PRODUCTION TECHNOLOGY
(2022)
Article
Energy & Fuels
Hao Yan, Jixiong Zhang, Nan Zhou, Peitao Shi, Xiangjian Dong
Summary: This paper proposes a new hybrid intelligent model based on firefly algorithm, sparrow search algorithm, and support vector machines for predicting the permeability alteration of coal during CO2 geological storage. The results show that the model has good accuracy and can provide guidance for promoting and applying CO2 storage technology.
GEOMECHANICS AND GEOPHYSICS FOR GEO-ENERGY AND GEO-RESOURCES
(2022)
Article
Chemistry, Multidisciplinary
Jianshe Linghu, Minmin Li, Gaowei Yue
Summary: A comprehensive technology combining drilling and mechanical cavitation is proposed to address the issues of coal and gas outburst and difficult extraction in soft, low-permeability, and high-gas seams. Through numerical simulation and experimental tests, the mechanical characteristics of drilling and mechanical cavitation in the coal seam are studied. The results show that this technology has a significant impact on the pressure relief and permeability improvement of the coal seam.
Article
Green & Sustainable Science & Technology
Liangliang Jiang, Zhangxin Chen, S. M. Farouq Ali, Jiansheng Zhang, Yanpeng Chen, Shanshan Chen
Summary: Underground coal gasification (UCG) has great potential in extracting energy from deep coal seams with low environmental impact. CO2 storage in post-UCG cavities was found to be stable and effective. The findings will promote the application of UCG in deep coal seams worldwide and facilitate the transition of the coal industry towards carbon-consciousness.
JOURNAL OF CLEANER PRODUCTION
(2022)
Article
Geosciences, Multidisciplinary
LingRui Kong, YongJiang Luo, JianXin Tang, YanLei Wang, Fang Yuan, Shuang Li, YongJin Hao
Summary: This study investigates the permeability damage characteristics of contaminated coal samples using a core flow test method. The results show that the permeability of contaminated coal samples decreases significantly due to water-sensitive damage, water locking, and bentonite and polymer molecule plugging. However, higher gas pressure can increase the permeability of contaminated coal samples. The intrusion of water and solid phase into coal samples reduces the influence of stress on permeability. This research has theoretical and practical significance in supporting the reformation of underground pressurized drilling methods and drilling fluid design.
NATURAL RESOURCES RESEARCH
(2023)
Article
Energy & Fuels
Jiale Zhao, Mengdi Sun, Zhejun Pan, Bo Liu, Mehdi Ostadhassan, Qinhong Hu
Summary: This study evaluated the permeability of deep shales in the Yichang area, Middle Yangtze using three methods and found significant differences in horizontal and vertical permeability. Microfractures and laminae were identified as the dominant gas transport channels, and increasing water saturation led to a decrease in matrix permeability.
ADVANCES IN GEO-ENERGY RESEARCH
(2022)
Article
Energy & Fuels
Mengdi Sun, Jianjiang Wen, Zhejun Pan, Bo Liu, Tomasz P. Blach, Yeping Ji, Qinhong Hu, Bingsong Yu, Chunming Wu, Yubin Ke
Summary: The characterization of pore accessibility in shale oil and gas reservoirs is essential but challenging. This study used contrast-matching small-angle neutron scattering (CM-SANS) and other experiments to investigate nanoscale pore accessibility characteristics and their controlling factors in overmature marine shale samples. A novel accessibility index was developed and used to analyze the accessibility of different wetting phases in nanoscale pore networks. The results showed that toluene filled higher pore volumes (>7 nm) due to the development of organic pores and their connection with inorganic pore systems, while water-accessible pores were observed within a pore size of less than 7 nm. The accessibility to water and toluene was controlled by pore surface wettability and pore connectivity. CM-SANS is an effective means of evaluating nanoscale pore accessibility in shale.
INTERNATIONAL JOURNAL OF COAL GEOLOGY
(2022)
Review
Energy & Fuels
Yi Xu, Zengmin Lun, Zhejun Pan, Haitao Wang, Xia Zhou, Chunpeng Zhao, Dengfeng Zhang
Summary: This article reviews the occurrence state of shale oil and analyzes the factors influencing its reservoir, emphasizing the importance of accurately estimating reserves and optimizing production.
JOURNAL OF PETROLEUM SCIENCE AND ENGINEERING
(2022)
Article
Geochemistry & Geophysics
Zhaoyi Liu, Zhejun Pan, Shibin Li, Ligang Zhang, Fengshan Wang, Changhao Wang, Lingling Han, Yuanyuan Ma, Hao Li, Peng Wang, Yize Huang
Summary: The efficient development of fractured volcanic reservoir relies on hydraulic fracturing, and the optimization of parameters under single-stage action is crucial for the development of volcanic gas reservoirs. Through methods such as logging interpretation, coring observation, and seismic interpretation, the degree of fracture development in volcanic reservoirs is studied, and hydraulic fracturing optimization design is conducted through numerical simulation and orthogonal tests.
Article
Geosciences, Multidisciplinary
Bin Zhang, Yafei Zhang, Suping Zhao, Wei He, Shu Tao, Zhejun Pan, Yi Cui
Summary: This study conducted CH4 isothermal adsorption measurements on 64 coal samples from western Guizhou Province in China and quantitatively analyzed the desorption processes of coalbed methane (CBM). The results indicate that coalification affects the Langmuir volume and pressure, which tend to increase with higher vitrinite reflectance. The CBM desorption process was divided into four stages (inefficient, slow, fast, and sensitive) using three key pressure nodes. The fast and sensitive desorption stages are crucial for achieving high gas production.
FRONTIERS OF EARTH SCIENCE
(2023)
Article
Engineering, Chemical
Yongkai Qiu, Hui Wang, Guangshan Guo, Rujun Mo, Zhejun Pan, Yidong Cai, Abulaitijiang Abuduerxiti
Summary: This study systematically evaluates the gas content and its geological control factors in the Weibei Field of the southeastern Ordos Basin, North China. The results indicate that the variability in gas content is largely influenced by the subsidence and fluctuation of the coal seam, while gas migration and preservation are controlled by fault types, roof lithology, burial depth, and hydrodynamic conditions. The identified geological models for gas content control are hydrodynamic trapping in deep burial depth and thrust faults, and gas loss due to groundwater flushing and normal faults.
Article
Engineering, Geological
Jun Zhang, Qiangang Yu, Yuwei Li, Zhejun Pan, Bo Liu
Summary: This study investigates the vertical propagation mechanism of hydraulic fractures in interlayered brittle shale formations. Experimental modeling and quantitative analysis are conducted to study the effects of geological and engineering factors on fracture propagation behavior. The results show that interlayer dip angle, vertical in situ stress difference, and interface cementation strength are important factors affecting fracture propagation. The brittleness characteristics of the interlayer also have a significant impact. The findings provide a deeper understanding of fracture geometry and the fracture intersection mechanism, offering accurate guidance for fracturing parameter optimization.
ROCK MECHANICS AND ROCK ENGINEERING
(2023)
Article
Energy & Fuels
Yu Suo, Muyu Dong, Zijian Wang, Jiahao Gao, Xiaofei Fu, Zhejun Pan, Kun Xie, Tiantian Qi, Guanzhong Wang
Summary: Understanding the characteristics of mixed-mode I-II fracture in mud shale is of high practical significance. A numerical model of a semi-circular bend specimen is built and calibrated to reveal the variation characteristics of stress field, displacement field, and fracture toughness during fracture initiation and propagation. The influence of bedding angle and strength on fracture behavior is discussed.
JOURNAL OF PETROLEUM SCIENCE AND ENGINEERING
(2022)
Article
Energy & Fuels
Zhenhua Han, Luqing Zhang, Jian Zhou, Zhejun Pan, Song Wang, Ruirui Li
Summary: This study investigates the influence of hydrate occurring mechanisms, saturation, and confining pressure on the mechanical properties of hydrate-bearing sediments. The results suggest that the cementation mode of hydrate has the most significant effect on the strength enhancement of sediments.
JOURNAL OF NATURAL GAS SCIENCE AND ENGINEERING
(2022)
Article
Geosciences, Multidisciplinary
Hongyan Qu, Yan Peng, Zhejun Pan, Xiangdong Xu, Fujian Zhou
Summary: Water-flooding is an effective method for developing extra-low permeability oil reservoirs, but water-rock interactions can alter geomechanical properties and impact the propagation of water-flooding induced fractures (WIFs). This study proposes a method to calculate WIF propagation length and establishes numerical models considering the effect of water-rock interactions. The models are validated and the mechanism and impact of water-rock interactions on WIF propagation are analyzed.
FRONTIERS IN EARTH SCIENCE
(2023)
Article
Thermodynamics
Ruirui Li, Luqing Zhang, Jian Zhou, Zhenhua Han, Zhejun Pan, Holger Schuettrumpf
Summary: This study investigates the influence of mineral particle shape and pore-filling natural gas hydrate (NGH) on permeability anisotropy. Simulation methods are used to construct numerical samples and calculate anisotropic permeabilities. The results show that elongated particles have minimal effect on permeability anisotropy, while preferential alignment of plate-shaped particles is the main cause. Understanding the formation mechanism of permeability anisotropy has potential applications in NGH exploitation, groundwater environment protection, and geological disaster prevention.
Review
Geosciences, Multidisciplinary
Changqing Fu, Yi Du, Wenlei Song, Shuxun Sang, Zhejun Pan, Ning Wang
Summary: Automated Mineralogy (AM) is a semi-automatic mineralogical tool that uses a scanning electron micrography-energy dispersion spectrometry (SEM-EDS) platform. It can analyze sedimentary environments, diagenetic evolution processes, and evaluate oil and gas reservoirs. The combination of AM and CT scanning can improve the accuracy of mineral distribution and be applied to study fluid reactive transport effects.
MARINE AND PETROLEUM GEOLOGY
(2023)
Article
Engineering, Chemical
Duo Wang, Sanbai Li, Dongxiao Zhang, Zhejun Pan
Summary: The transport mechanism of densely-packed proppant bed is numerically investigated using the lattice Boltzmann-discrete element coupling method (LB-DEM). This study focuses on the bedload transport of settled proppants in the primary fracture. The results show a nonlinear relationship between particle flux and fluid flux, which is attributed to the shear-thinning property of the proppant bed. The research contributes to an improved hydraulic fracturing operation by optimizing the fracturing fluid injection scheme and proppant flowback control.
Review
Energy & Fuels
Biao Hu, Yuanping Cheng, Zhejun Pan
Summary: The pore structures in coal are crucial for the occurrence and migration of coalbed methane (CBM), which plays a significant role in CBM extraction, utilization, and coal mining disaster prevention. Existing pore classification methods for coal have their drawbacks, thus this paper systematically reviews previous methods and proposes a new pore classification based on the characteristics of CH4 occurrence and migration in coal. This new method categorizes pore structures into four types and provides a more intuitive understanding of CBM occurrence and migration.
GAS SCIENCE AND ENGINEERING
(2023)
Review
Energy & Fuels
Qing Liu, Mengdi Sun, Xianda Sun, Bo Liu, Mehdi Ostadhassan, Wanxia Huang, Xiaoxia Chen, Zhejun Pan
Summary: X-ray computed tomography (X-ray CT) scanning is a non-destructive visualization technology that can be used to characterize multiscale shale pore structures and assess their permeability. Various imaging techniques, such as micro-CT, nano-CT, FIB-SEM, and contrast agent injections, provide a powerful approach for evaluating shale microstructures. Additionally, digital rock physics (DRP) based on 3D visualization can be used for flow modeling and predicting transport properties. CT scanning can also capture the significant evolution of microstructures during geological processes or hydrocarbon exploitation.
GAS SCIENCE AND ENGINEERING
(2023)
