Wei Sun^1,2, Yanqing Feng^1,2,*, Yuan Wang^1,2, Zengping Zhao^1,2, Qian Wang², Xiangyun Li³, Dong Feng⁴

FDMP-Fluid Dynamics & Materials Processing, Vol.22, No.1, 2026, DOI:10.32604/fdmp.2026.075630 - 06 February 2026

Abstract Significant differences exist between deep and medium-shallow coalbed methane (CBM) reservoirs. The unclear understanding of flowback and production behavior severely constrains the development of deep CBM resources. To address this challenge, guided by the gas-liquid two-phase flow theory in ultra-low permeability reservoirs, and integrating theoretical analysis, numerical simulation, and insights from production practices, this study classifies the flowback and production stages of deep CBM well considering the Daning-Jixian Block, Eastern Ordos Basin as a representative case. We summarize the flowback characteristics for each stage and establish a standard flowback production type curve, aiming to guide… More > Graphic Abstract

Zhirong Jin^1,*, Xiaorui Hou¹, Yanrong Ge¹, Tiankui Guo², Ming Chen², Shuyi Li², Tianyu Niu²

Energy Engineering, Vol.123, No.2, 2026, DOI:10.32604/ee.2025.070750 - 27 January 2026

Abstract Hydraulic fracturing serves as a critical technology for reservoir stimulation in deep coalbed methane (CBM) development, where the mechanical properties of gangue layers exert a significant control on fracture propagation behavior. To address the unclear mechanisms governing fracture penetration across coal-gangue interfaces, this study employs the Continuum-Discontinuum Element Method (CDEM) to simulate and analyze the vertical propagation of hydraulic fractures initiating within coal seams, based on geomechanical parameters derived from the deep Benxi Formation coal seams in the southeastern Ordos Basin. The investigation systematically examines the influence of geological and operational parameters on cross-interfacial fracture… More >

Li Wang¹, Xuesong Xing¹, Yanan Hou¹, Heng Wen¹, Ying Zhu¹, Jingyu Zi¹, Qingwei Zeng^2,3,*

Energy Engineering, Vol.123, No.2, 2026, DOI:10.32604/ee.2025.068653 - 27 January 2026

Abstract The deep coal reservoir in Linxing-Shenfu block of Ordos Basin is an important part of China’s coalbed methane resources. In the process of reservoir reconstruction, the artificial fracture morphology of coal seam with gangue interaction is significantly different, which affects the efficient development of coalbed methane resources in this area. In this paper, the surface outcrop of Linxing-Shenfu block is selected, and three kinds of interaction modes between gangue and coal seam are set up, including single-component coal rock sample, coal rock sample with different thicknesses of gangue layer and coal rock sample with different… More >

Haoxuanye Ji^*, Zhiliang Chen, Pengfei Jiang, Ziyue Wang, Ting Yu, Wei Zhang

CMC-Computers, Materials & Continua, Vol.86, No.3, 2026, DOI:10.32604/cmc.2025.071880 - 12 January 2026

Abstract Foreign body classification on coal conveyor belts is a critical component of intelligent coal mining systems. Previous approaches have primarily utilized convolutional neural networks (CNNs) to effectively integrate spatial and semantic information. However, the performance of CNN-based methods remains limited in classification accuracy, primarily due to insufficient exploration of local image characteristics. Unlike CNNs, Vision Transformer (ViT) captures discriminative features by modeling relationships between local image patches. However, such methods typically require a large number of training samples to perform effectively. In the context of foreign body classification on coal conveyor belts, the limited availability… More >

Xia Yan¹, Wei Wang¹, Kai Shen^2,*, Yanqing Feng¹, Junyi Sun¹, Xiaogang Li¹, Wentao Zhu¹, Binbin Shi¹, Guanglong Sheng^2,3

Energy Engineering, Vol.123, No.1, 2026, DOI:10.32604/ee.2025.070360 - 27 December 2025

Abstract In the development of coalbed methane (CBM) reservoirs using multistage fractured horizontal wells, there often exist areas that are either repeatedly stimulated or completely unstimulated between fracturing stages, leading to suboptimal reservoir performance. Currently, there is no well-established method for accurately evaluating the effectiveness of such stimulation. This study introduces, for the first time, the concept of the Fracture Network Bridging Coefficient (FNBC) as a novel metric to assess stimulation performance. By quantitatively coupling the proportions of unstimulated and overstimulated volumes, the FNBC effectively characterizes the connectivity and efficiency of the fracture network. A background… More >

Luthfi Hakim^1,*, Yunida Syafriani Lubis², Apri Heri Iswanto¹, Harisyah Manurung¹, Jayusman², Widya Fatriasari³, Petar Antov⁴, Tomasz Rogoziński⁵, Lee Seng Hua⁶, Nur Izyan Wan Azelee⁷

Journal of Renewable Materials, Vol.13, No.12, pp. 2355-2373, 2025, DOI:10.32604/jrm.2025.02025-0078 - 23 December 2025

Abstract Activated charcoals were synthesized from sugar palm bunches (SPB) of the native tree of Arenga longipes in Indonesia. The synthesized activated charcoal (AC) was characterized, and utilized as an absorbent for heavy metals (lead/Pb and copper/Cu) through thermal activation. The synthesis of AC was accomplished through furnace activation at temperatures of 500°C, 600°C, 700°C, and 800°C. Acid chlorides were blended with the SPB-AC samples at 5% impregnation level and subsequently subjected to washing for activation, resulting in the elimination of volatile substances and ash content, which facilitates the development of a porous structure in the activated… More >

Tao Lin^1,*, Chengdai Chen¹, Liyao Chen¹, Fengqin Han¹, Guanghui He²

Frontiers in Heat and Mass Transfer, Vol.23, No.5, pp. 1661-1680, 2025, DOI:10.32604/fhmt.2025.070787 - 31 October 2025

Abstract Targeting spontaneous coal combustion during stacking, we developed an efficient heat dissipation & self-supplied wireless temperature measurement system (SPWTM) with gravity heat pipe-thermoelectric integration for dual safety. The heat transfer characteristics and temperature measurement optimization of the system are experimentally investigated and verified in practical applications. The results show that, firstly, the effects of coal pile heat production power and burial depth, along with heat pipe startup and heat transfer characteristics. At 60 cm burial depth, the condensation section dissipates 98% coal pile heat via natural convection. Secondly, for the temperature measurement error caused by… More >

Zhiyuan Zhang¹, Meng Shuai², Bin Wang¹, Ying He³, Fan Yang¹, Liyan Ren^4,*, Yuyuan Zhang⁴, Ziren Wang⁴

Energy Engineering, Vol.122, No.10, pp. 4169-4194, 2025, DOI:10.32604/ee.2025.066793 - 30 September 2025

Abstract With the rapid development of renewable energy, the Microgrid Coalition (MGC) has become an important approach to improving energy utilization efficiency and economic performance. To address the operational optimization problem in multi-microgrid cooperation, a cooperative game strategy based on the Nash bargaining model is proposed, aiming to enable collaboration among microgrids to maximize overall benefits while considering energy trading and cost optimization. First, each microgrid is regarded as a game participant, and a multi-microgrid cooperative game model based on Nash bargaining theory is constructed, targeting the minimization of total operational cost under constraints such as More >

Mingyang Zhao^1,2,*, Xiaojun Li^1,3, Miao Li^1,2, Bangbang Mu^1,2

CMC-Computers, Materials & Continua, Vol.84, No.2, pp. 2827-2846, 2025, DOI:10.32604/cmc.2025.065251 - 03 July 2025

Abstract The control of gas extraction in coal mines relies on the effectiveness of gas extraction. The main method of gas extraction is to drive drill pipes into the coal seam through a drilling rig and use technologies such as hydraulic fracturing to pre-extract gas in the drill holes. Therefore, the real-time detection of the drill pipe status is closely related to the effectiveness of gas extraction. To achieve fast and accurate identification of drill pipes, we propose FSS-YOLO, which is a lightweight drill pipe detection method based on YOLOv8n-obb. This method first introduces the FasterBlock… More >

Xuesong Xing¹, Li Wang¹, Guangai Wu¹, Chengyong Peng^1,2,3, Yanan Hou¹, Jingyu Zi¹, Biao Yin^2,3,*

Energy Engineering, Vol.122, No.7, pp. 2911-2930, 2025, DOI:10.32604/ee.2025.065384 - 27 June 2025

Abstract Hydraulic fracturing, an effective method for enhancing coal seam productivity, largely determines coalbed methane (CBM) production, which is significantly influenced by geological and engineering factors. This study focuses on the L block to investigate the mechanisms influencing efficient fracture propagation and enhanced stimulated reservoir volume (SRV) in fracturing. To explore the mechanisms influencing effective fracture propagation and enhanced SRV, the L block was selected as the research object, with a comprehensive consideration of geological background, reservoir properties, and dynamic production data. By combining the discrete lattice method with numerical analysis and true triaxial experimental simulation,… More >