Oil, Gas, and Energy Commons^™

Optical Mechanisms Behind Vitrinite Reflectance Suppression Caused By Strong Anisotropy: A Case Study Of Contact Metamorphic Coals, An Yanfei, He Shuyang, Chen Kaixin, Gao Junhan

Coal Geology & Exploration

Objective For vitrinite with weak anisotropy, which proves uniaxial and optically negative, replacing random vitrinite reflectance (R_ran) with the maximum vitrinite reflectance (R_max) allows for the accurate correction of vitrinite reflectance suppression induced by anisotropy. However, as its anisotropy intensifies, vitrinite exhibits increasingly complex optical properties, rendering it challenging to reflect the thermal metamorphic temperature of vitrinite using R_max. Methods This study investigated the strongly anisotropic vitrinite in coals and natural coke subjected to magma intrusion in the Shitai coal mine, Huaibei City, Anhui Province. Using a reflected-polarized light microscope (R-PLM), an …

Mechanisms Behind Thermal Evolution Of The Structural Alignment Of Polycyclic Aromatic Hydrocarbons In Coals: Implications For Structural Transition Of Coal Macromolecules, Song Yu, Jiang Bo, Cheng Guoxi, Zheng Sijian, Li Ming, Ge Yao, Dai Yan, Wang Qian, Feng Guangjun

Coal Geology & Exploration

Objective Coals are highly sensitive to variations in temperature and pressure conditions. The structural evolution of coal macromolecules, driven by tectono-thermal processes, is the key to understanding coal rank transition and geological evolution. The structural alignment of polycyclic aromatic hydrocarbons (PAHs) in coals represents a critical indicator for characterizing coal rank transition and geological evolution. However, due to limited studies, there is a lack of systematic experimental demonstration and theoretical support for the structural alignment and microstructural characteristics of PAHs in coals, as well as their intrinsic relationships with the structural transition of coal macromolecules, during pyrolysis. Methods This study …

Sedimentary Characteristics And Coal Accumulation Patterns Of The Permian Shallow-Water Deltas In Shandong And Its Adjacent Regions, Feng Kai, Li Zengxue, Li Ying, Li Xuchao, Zhang Hui, Zhou Xiaojuan

Coal Geology & Exploration

Objective The Shanxi Formation, deposited during the critical transitional period from the sedimentary filling of epicontinental sea basins to the sedimentation of continental basins, exhibits well-developed shallow-water delta systems and significant coal-forming processes. This study aims to reveal the characteristics of sedimentary environment transformation during the late stage of sedimentary filling of epicontinental sea basins in North China. To this end, the Early Permian shallow-water delta systems in Shandong and its adjacent regions during that period was investigated, including their primary sedimentary characteristics, the predominant bases of sedimentary transformation, and the lithofacies paleogeographic characteristics of coal-forming processes.Methods Based on …

Geological Characteristics And Enrichment-Accumulation Patterns Of Coalbed Methane Within The Jurassic Strata In The Miquan Area Along The Southern Margin Of The Junggar Basin, Wu Luofei, Yang Kangjun, Zhang Jie, Shi Yongxia, Fu Haijiao, Yang Shuguang, Wang Gang, Liu Mengmeng, Li Yueguo, Wang Xiaoming

Coal Geology & Exploration

Objective The southern margin of the Junggar Basin (also referred to as the southern Junggar) possesses abundant medium- to low-rank coalbed methane (CBM) resources, with significant progress achieved in CBM exploration and production. However, there remains a lack of systematic understanding of the genetic mechanisms of CBM within the Middle-Lower Jurassic strata, along with its accumulation and evolution laws, in the Miquan area, southern Junggar. This absence restricts the commercial development of CBM in these strata.Method Focusing on CBM within the Middle-Lower Jurassic Xishanyao and Badaowan formations in the Miquan area, this study further identified the CBM origins and …

Evaluation And Research Progress Of Co2 Sequestration In Deep Coal Seams, Xiong Yucan, Xu Shi’Ang, Zhang Pingsong, Lu Haifeng, Jia Yunzhong, Ge Binbin, Li Baiqiang, Liu Chang, Lei Jian, Fu Wenyu

Coal Geology & Exploration

Background With increasing pressure for global carbon emission reduction, geologic CO₂ sequestration has emerged as a critical technical approach to achieving the goals of peak carbon dioxide emissions and carbon neutrality. Owing to their high CO₂ adsorption capacity and favorable sealing conditions, deep coal seams are considered one of the most promising media for CO₂ sequestration, following saline aquifers and depleted hydrocarbon reservoirs. Therefore, the exploitation and utilization of deep coal seams hold significant strategic importance for the green, low-carbon transformation of the coal industry. Methods Based on literature analysis and a review of outcomes from cutting-edge …

Mechanisms Behind The Impacts Of Co2 Concentration On Microbial Methanogenesis In Coal Seams, Wang Junyu, Liu Bingjun, Jiang Xiangqing, Chen Ruifeng, Xue Sheng, Zhou Wanlong, Yang Yundu

Coal Geology & Exploration

Background Coal seams exhibit the extensive distribution of a variety of indigenous functional microorganisms. Among these, some archaea enable methane metabolism using CO₂ as a substrate, providing the potential for the biological CO₂ storage and utilization in coal seams. However, conventional studies focus primarily on the degradation characteristics of coal matrix, leading to a lack of a systematic understanding of the mechanisms governing the adjustment of the methanation process in CO₂-bearing environments. Methods This study investigated the bituminous coals with a high volatile content in the Huainan mining area. Using laboratory-scale experiments on methanogenesis through anaerobic …

Dynamic Prediction On Goaf Surface Subsidence For The Last Two Periods Based On The Erf Time Function, Ren Lianwei, Li Shihui, Wang Wenchang, Li Zhenhua, Chen Shaojie, Dun Zhilin

Coal Geology & Exploration

Background The surface subsidence induced by coal seam mining represents a continuous dynamic evolution process. Constructing a full-time perdition model for surface subsidence in goafs holds significant theoretical and practical values for the rational utilization of land resources, the safety guarantee of engineering construction, and the transformation and development of resource-based cities. Methods To accurately predict the surface subsidence in goafs during its decline and residual periods, this study proposed a prediction model based on the error function (Erf). First, the evolution characteristics of Erf were analyzed, verifying that the subsidence, as well as its velocity and acceleration, predicted using …

Exploring Water Migration Patterns In Reconstructed Soil Layers For Waste Dumps Of Open-Pit Coal Mines Based On Ct Scanning, Fan Tingyu, Zhang Xinghui, Lu Akang, Yang Changde, Wang Shun, Wang Xingming, Sun Xueliang, Ji Quancai

Coal Geology & Exploration

Objective In the arid regions of western China, the ecological restoration of waste dumps within open-pit coal mines plays a key role in green mine construction, while creating a suitable soil profile structure serves as a prerequisite for the ecological restoration.Methods This study investigated the reconstructed soils with a three-layer sponge-like structure consisting of the topsoil, sandy-soil, and mudstone layers for the waste dump of the Hongshaquan open-pit coal mine in Xinjiang. Using computed tomography (CT) scanning, a three-dimensional (3D) pore network model (PNM), and water migration simulation, this study systematically analyzed the pore structures and water migration characteristics …

Technologies For Controlling Water Inrushes From Coal Seam Floors Under Flowing Water And Their Water Plugging Performance, Yang Zhibin

Coal Geology & Exploration

Objective Limestone water hazards in coal seam floors represent one of the two primary categories of mine water hazards in China. Limestone aquifers are generally characterized by abundant static water reserves and considerable dynamic water recharge. To reduce economic losses and casualties caused by water inrushes from limestone aquifers, post-disaster emergency rescue through grouting for water plugging is frequently carried out under flowing water.Methods Based on numerous cases of water inrush control under flowing water in China and the fundamental requirements for control scheme design, this study presents a systematic review of existing technologies for water inrush control under …

Performance Optimization Of Superfine Cement Through Composite Modification Using Coal-Based Solid Waste And Modifiers, Kang Zhipeng, Luo Yong, Xiao Diancai, Ren Shuai, Cai Zhiliang, Gao Xiang, Zhang Kunzhe

Coal Geology & Exploration

Objective Superfine cement-based grouting materials generally suffer from limitations including high bleeding rates, unfavourable rheological properties, poor stability, and strength retrogression. These issues can be mitigated by incorporating modifiers, which allows for the reutilization of coal-based solid waste while enhancing the performance of composite, superfine cement-based grouting materials. Methods Superfine cement-based grouting materials with different mixing ratios were prepared by using superfine cement as the basic material, fly ash (FA) and mineral fines (MFs) as primary admixtures, and modified bentonite, methyl cellulose ether (MCE), U-type expansive agent (UEA), and magnesium oxide (MgO) as modifiers. These grouting materials and pure superfine …

Joint Inversion For Heat Transfer Parameters Of Porous Media With Geothermal-Seepage Coupling Based On A Physics-Informed Neural Network, Zhang Xiao, Yang Duoxing, Cong Lin, Cheng Yimei, Zhang Lianzhong

Coal Geology & Exploration

Background The thermal diffusivity and vertical seepage velocity of porous media are critical to characterizing the mechanisms underlying subsurface heat transfer. These two parameters are typically determined through inversion using temperature data since they are difficult to measure directly. Fiber-optic distributed temperature sensing (FO-DTS) can yield high-resolution, continuous temperature profiles, providing data for parameter identification. However, conventional numerical inversion suffers from limitations such as mesh dependency and sensitivity to initial values when used to process continuous monitoring data. Methods This study proposed a joint geothermal parameter inversion method that integrates FO-DTS data with a physics-informed neural network (PINN). Specifically, the …

Mine Data Fusion Technology Based On Multi-Feature Joint Decision Making, Han Shanshan, Zhang Jifeng, Fan Tao, Liu Qiang, Song Xiaojiao, Qi Zhipeng, Zheng Hangzhou

Coal Geology & Exploration

Background In the field of geological exploration of coal mines, methods such as in-seam seismic exploration, the transient electromagnetic method, and audio-frequency electrical penetration offer unique technical advantages. However, each of these methods can only reflect a single physical property of a medium, suffering from limitations including the one-sidedness of information and the multiple solutions of interpretations, thus failing to adapt to the new situations of current coal mine exploration. Multi-source data fusion promotes a technological development by leaps from one-sided detection to comprehensive analysis through mechanisms of information complementation, feature enhancement, and field-source integration. Therefore, this technology can enhance …

Joint Inversion Of Borehole-Surface Direct-Current Resistivity Data, Xu Kaijun, Jin Heran, Cao Danping, Mou Bin, Hu Zuzhi

Coal Geology & Exploration

Objective The conventional inversion of surface direct-current (DC) resistivity data faces challenges such as limited exploration accuracy and depth. This study aims to enhance the accuracy and reliability of exploration in complex engineering and geological settings through the joint inversion of borehole-surface DC resistivity data. Methods First, different geoelectric models were constructed through three-dimensional (3D) forward modeling of full-space DC resistivity. Then, the potential response characteristics under surface and borehole observation methods were systematically analyzed to determine the differences in detection sensitivity between surface and borehole observations. Accordingly, a joint 3D inversion technique for borehole-surface DC resistivity data was developed …

Oil-Based Mud Electrical Imaging Logging Responses Of Carbonate Strata, Wu Yuyu, Lai Qiang, Pan Feng, Zhao Zuo’An, Wang Xiaoxing, Wang Yue, Cheng Lu, Wang Zeyu, Yin Rong

Coal Geology & Exploration

Objectives This study aims to characterize the oil-based mud (OBM) electrical imaging logging responses of carbonate strata, highlighting the response characteristics of dissolution vugs, fractures, stratigraphical structures, and special minerals. Methods Tests were conducted on logging data acquisition of a drilled well within the Dengying Formation in the Sichuan Basin before and after OBM was replaced with water-based mud (WBM). Based on the fine-scale core-to-log (CTL) calibration, this study compared the WBM and OBM electrical imaging logging responses of different geological and pore structures. Furthermore, the characteristics of OBM electrical imaging logging responses were further discussed from the measurement principles …

A Cutting Trajectory Planning Technology Driven By Coal Seam Data In A Comprehensive Mining Face, Guo Yifeng, Xue Xusheng, Ma Hongwei, Zhang Guangming, Su Hao, Qi Ailing, Nie Zhen, Ma Kexiang, Wu Xuefei

Coal Geology & Exploration

Objective Currently, the insufficient full-element digitization and the prevalence of “data silos” in fully mechanized mining faces (FMMF) result in poor cutting precision and operational instability of shearers under complex undulating and abrupt geological conditions. These factors pose significant challenges to high-precision proactive trajectory planning. Methods Guided by the academic philosophy that “mining is data acquisition”, this paper proposes a coal seam data-driven cutting trajectory planning method for FMMFs. It elaborates on three core technologies: high-precision digital coal seam modeling, generative model updating and digital twin construction, and data-driven trajectory planning.To address low modeling precision, an intelligent interpolation-based digital coal …

Image Processing Technique To Find The Burden Rock Velocity And Its Interdependency On Bench Blasting Parameters – A Case Study, Channabassamma N, Akhil Avchar, Sahas V Swamy, Vedala Rama Sastry, Hemant Agrawale

Journal of Sustainable Mining

In any rock engineering or excavation project, optimizing blast design is essential for controlling post-blast phenomena such as flyrock, burden throw, and burden rock velocity (BRV). This study investigates the dynamic response of BRV in bench blasting operations by employing a high-speed camera and ProAnalyst software to quantify rock displacement. The relationships between BRV and key blast parameters, number of holes (NH), explosive charge per hole (EPH), total explosive charge (TEC), stiffness ratio (K), and stemming ratio (STR), were analyzed to identify linear or non-linear trends. Non-linear trends, …

Analysis And Study Of Telemetry Systems For Directional And Horizontal Well Drilling, Jahongir Abdiganiyev Erkin Ugli, Sherali Halloqovich Umedov

Technical science and innovation

The article discusses the issues of reducing non-productive drilling time during the construction of directional and horizontal wells. The main focus is on the analysis of drilling conditions in complex geological and high-temperature environments. Particular attention is paid to drilling conditions in the territory of the Republic of Uzbekistan, with a specific study of data from the Boysun and Ustyurt regions. An analysis and study of the performance of telemetry systems available on the market, as well as their main technical characteristics, have been conducted. Key factors affecting the accuracy of wellbore trajectory measurements under various geological and technical conditions …

A Method To Accelerate Rock Breakage With Soundless Chemical Demolition Agents, Patrick A. Darko, Hani S. Mitri

Journal of Sustainable Mining

Soundless chemical demolition agents (SCDA) are recognized as a safe and sustainable alternative for rock breakage, with the potential to reduce reliance on explosives in mining. However, their mechanical performance is considerably hampered in the extreme cold climate, with slow or no rock fracturing observed. To overcome this deficiency, two methods were developed in recent studies by 1) electric heating the SCDA borehole with high-temperature wire, and 2) increasing the SCDA mixing water temperature. Good results were obtained with both methods. This paper explores the merits of a hybrid approach combining the two methods to further enhance the SCDA efficiency …

Research Status And Development Trend Of Acidification And Permeability Improvement Technology For Low-Permeability Coal Seam, Shaochuan Chen, Yun Lei, Fuchao Tian, Jie Kang

Journal of Sustainable Mining

Low-permeability coal seams in China are often characterized by mineral-clogged pore-fracture systems, severely limiting coalbed methane (CBM) extraction efficiency. Acidification technology, which involves injecting acidic solutions into coal seams to dissolve minerals and enhance permeability, has emerged as a promising approach. This paper systematically reviews the mechanisms, laboratory findings, and field applications of acidification technology for permeability enhancement in low-permeability coal seams. Key findings include significant improvements in pore connectivity, reductions in gas adsorption capacity, and enhanced gas extraction rates post-acidification. Field tests demonstrate that acid fracturing can increase gas extraction volume by 4-7 times. The study also identifies current …

Improving Energy Reliability In Mining Areas Through Modelling And Control Of Resonance Phenomena In Solar-Integrated Power Systems, Yurii Papaika, Gennadiy Pivnyak, Maksim Malyshko, Yuliya Pazynich, Natalia Howaniec, Adam Smolinski

Journal of Sustainable Mining

This study addresses the emergency and operational transient processes that arise when integrating large-scale solar power plants (SPPs) into electrical load nodes, particularly under conditions of limited power system capacity. With the increasing penetration of distributed generation in Ukraine's energy landscape, challenges related to electromagnetic compatibility and harmonic resonance are becoming more prominent. The research builds upon the foundational work of leading Ukrainian scientific schools and focuses on the specific resonance phenomena observed during the operation of solar inverters in medium-voltage networks, especially in regions with high industrial and mining Energy demand. A novel algorithm is proposed for determining the …

Feasibility Study Of Barite Sourcing From Sediments Emerging Due To Treatment Of Waste Water From Coal Mining, Hubert Makuła, Zbigniew Bzowski, Bogusław Michalik

Journal of Sustainable Mining

The accumulation of mine water in settling ponds, which is discharged due to coal mining, allows them to be cleaned out of suspension, and it is the reason for the accumulation of hundreds of thousands of tons of sediments. One interesting mineral enclosed in these sediments is barite, which is considered in the EU as a critical raw material, but it also contains radium originating from formation water.

The effective barite separation and its beneficiation could constitute a win-win solution because then it would be possible to obtain the valuable radium concentrate for further processing, e.g., in nuclear medicine, and …

Wettability Evaluation Via Contact Angle And Data Mining For Enhanced Oil Recovery, Syasya Wadihah Md. Ja’Afar, Bashir Busahmin

Journal of Sustainable Mining

The oil industry has used many enhanced oil recovery (EOR) strategies to increase crude oil production from reservoirs, particularly as production begins to fall. With a significant quantity of hydrocarbon reserves still existing in the reservoirs, improved oil recovery techniques have the potential to increase oil production, with wettability alteration playing a significant role. To date, there has been no comprehensive investigation of wettability in Brunei's sandstone reservoir. The goal of this research is to determine wettability by contact angle measurement and data mining approaches based on the Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) algorithm. …

Owning Geothermal Energy, Gabriel Eckstein

Michigan Journal of Environmental & Administrative Law

Geothermal energy holds vast potential for decarbonizing the U.S. energy system, yet the sector remains significantly underdeveloped, supplying only 0.4% of the nation's electricity. A principal barrier to growth is the fragmented and ambiguous legal landscape currently governing ownership of geothermal resources: thirty-three states lack any clear statutory or common-law framework identifying who owns subsurface thermal energy. This Article examines the physical characteristics of geothermal energy, recent developments in the U.S. geothermal sector, and the principal doctrinal approaches that might govern ownership of subsurface heat, including the ad coelum doctrine, common-pool and open-access frameworks, the rule of capture, and public …

Recovery Of Bioenergy From Industrial Wastewater Using Microbial Fuel Cell, Syed Wamiq Ali, Ghulam Mujtaba, Manzoor Ahmed Sanjrani, Falak Shad

Journal of Bioresource Management

Water problems and Energy demands are increasing particularly in developing countries. Researchers are looking for sustainable technologies that can address increasing energy and environmental concerns. Major reasons behind those emerging concerns are industrialization and rapid development. There is need of sustainable technology which can solve wastewater issues and fulfill energy demand. One of the emerging technologies that have been studied comprehensively is Microbial Fuel Cell (MFC). It is a bio-electrochemical conversion technology that converts organic substrate into electrical energy. Chemical Oxygen Demand (COD) is removed as a result of microbial metabolism of organic substrate. Even through technical and economic aspects …

Dynamic Evolution Of Rock Mechanical Properties Of Coal Seam Roofs Under Thermal Loading: A Case Study Of The Baikouquan Area, Xinjiang, China, Sun Fangfang, Li Xin, Sang Shuxun, Qu Huailin, Yang Shuguang, Wei Bo, Wang Ziqiang, Zhang Bin, Chen Yanpeng, Tian Wenling

Coal Geology & Exploration

Objective Underground coal gasification (UCG) represents a key technology for the clean utilization of coal resources. However, during the UCG process, thermal damage to surrounding rocks under thermal effects directly affects the stability and engineering safety of gasification channels.Methods To address the thermal damage to surrounding rocks during UCG, this study investigated the silty mudstones and coarse-grained sandstones in the coal seam roof of the Xishanyao Formation, Baikouquan area, Xinjiang. Through high-temperature uniaxial compression experiments, combined with characterization methods like X-ray diffraction (XRD) and scanning electron microscopy (SEM), this study delved into the dynamic evolutionary patterns of rock mechanical …

Positive And Negative Pressure Distributions And Gas Migration Mechanisms Under Gas Drainage From Coal Seams Using Ultra-Long Directional Boreholes, Li Quanxin, Zhao Yuechen, Mou Quanbin, Wang Liang, Fang Jun, Wang Chenghao

Coal Geology & Exploration

Background Gas drainage via ultra-long directional boreholes plays a significant role in gas control in coal mines. To ensure safe and efficient gas drainage using these boreholes, it is critical to determine the mechanisms behind positive- negative pressure coupling, as well as the dominant mechanisms governing gas migration. However, the evolutionary patterns of positive-negative pressure zoning within the boreholes and the primary factors influencing gas drainage efficiency have yet to be accurately characterized. Methods Under the engineering background of the Shendong Baode Coal Mine, this study developed a multi-field coupling model integrating diffusion, seepage, and in-borehole flow fields based on …

Spatiotemporal Variations And Their Influencing Factors For Vegetation Net Primary Productivity In The Shendong Coal Base, Yang Fei, Cui Kuankuan, Zhang Chengye, Li Jun, Dong Qiulin

Coal Geology & Exploration

Objective The Shendong coal base, located within the arid and semi-arid regions in western China, is identified as the region with the most pronounced contradiction between coal resource development and ecological conservation in the country. Analyzing the spatiotemporal variations in the ecosystem and their influencing factors at the base scale provides a necessary foundation for green mine construction while also offering critical support for regional sustainable development.Methods In this study, the vegetation net primary productivity (NPP) was selected as an indicator for the ecological evaluation of mining areas. By integrating data on terrain, weather and climate, socio-economy, and human …

Soil Microbial Biomass And Organic Carbon Fractions Under Different Natural Restoration Years In Arid Coal Mining Subsidence Areas In Xinjiang, China, Xiao Li, Bi Yinli, Wang Dongdong, Li Jianfeng, Gong Hanlin, Deng Aojuan, Hou Wensheng

Coal Geology & Exploration

Objective This study aims to elucidate the influence of the natural restoration process on changes in soil microbial biomass and organic carbon fractions in coal mining subsidence areas. This effort will provide a crucial scientific foundation for understanding the natural ecological restoration process and carbon accumulation dynamics in arid coal mining subsidence areas.Methods Arid coal mining subsidence areas in Xinjiang, China were investigated in this study. Using the space-for-time substitution approach, sample plots were selected from an unmined area and areas having undergone natural restoration for one, three, eight, and 12 years. Subsequently, systematic analyses were conducted on the …

Application Of A Generative Adversarial Network To Super-Resolution Reconstruction Of Fracture Images In Logging-While-Drilling Electrical Resistivity Imaging, Han Sen, Shen Chuanhai, Xu Chen, Tian Yimeng, Zhao Biao, Wang Ze, Liu Yongkang, Kang Zhengming

Coal Geology & Exploration

Objective Logging-while-drilling electrical resistivity imaging (LWD-ERI) enables the intuitive presentation of geobodies near wellbores in images, representing an important approach to the fine-scale evaluation of stratigraphic parameters while also providing significant geological guidance during the drilling of fractured reservoirs. However, this technique faces the challenge of low image resolution in real-time data processing due to its limited well-to-surface data transmission rates, exerting adverse impacts on the qualitative identification of wellbore fractures and the quantitative evaluation of their parameters. To address this issue, this study proposed a super-resolution image reconstruction method based on a generative adversarial network (GAN), aiming to achieve …

An Experimental Study On The Mechanical Property Evolution Of Granites Post-High-Temperature Treatment Under Loading And Unloading Conditions, Hao Wencai, Qiao Wei, Liu Huichen, Zhu Zhennan, Wang Hao, Liu Richeng, Guo Jie, Xie Jingyu, Cheng Xianggang, Lyu Ruijie

Coal Geology & Exploration

Objective The surrounding rocks of wellbores remain in a state of stress release during the drilling and heat extraction of deep geothermal reservoirs. Therefore, investigating the characteristic stresses of heat-treated granites under loading and unloading conditions is critical to understanding the crack evolution in deep hot dry rock (HDR) reservoirs during their stimulation. Methods Targeting the granite specimens after heat treatment at varying high temperatures (e.g., 200 ℃, 300 ℃, 400 ℃, 500 ℃, and 600 ℃), this study conducted triaxial loading and unloading tests under a confining pressure of 60 MPa, aiming to investigate the impacts of high temperature …