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Full-Text Articles in Mining Engineering
Unique Connotation Of Geological-Engineering Dual Sweet Spot Evaluation For Effective Coalbed Methane Exploitation, Luo Pingya, Zhu Suyang
Unique Connotation Of Geological-Engineering Dual Sweet Spot Evaluation For Effective Coalbed Methane Exploitation, Luo Pingya, Zhu Suyang
Coal Geology & Exploration
Objective In China, the exploitation of deep and shallow coalbed methane (CBM) still relies on the evaluation approach oriented to the geological-engineering dual sweet spots of unconventional hydrocarbons. However, exemplary CBM production technologies delivered unsatisfactory performance in other blocks and failed to find wide application even in zones with overlapping geological and engineering sweet spots. This issue represents the principal theoretical and technical challenge confronting the comprehensive development of the CBM industry in China. Methods This study aims to elucidate the causes of this issue and provide corresponding solutions, as well as clarifying the conditions for the effective linkage between …
Differential Accumulation Of Coalbed Methane In Medium- To Low-Rank Coal Seams In A Strongly Compressional Tectonic Setting In The Tarim Basin, Liu Honglin, Wang Hongyan, Wang Haichao, Deng Ze
Differential Accumulation Of Coalbed Methane In Medium- To Low-Rank Coal Seams In A Strongly Compressional Tectonic Setting In The Tarim Basin, Liu Honglin, Wang Hongyan, Wang Haichao, Deng Ze
Coal Geology & Exploration
Background The Tarim Basin contains abundant coal and coalbed methane (CBM) resources. However, the geological accumulation patterns of CBM in the basin remain poorly understood. This leads to a relative lack of targeted technologies for the exploration and development of both deep coal reservoirs and steeply dipping coal seams, further rendering it challenging to achieve breakthroughs in CBM development in the basin. Methods Based on test data from 92 coal samples, data on the drilling and production tests of more than 10 exploration wells, and 3D seismic interpretation results, this study systematically investigated the distribution of coal-bearing strata, as well …
Components And Isotope Fractionation Of Deep Coalbed Methane And Their Geological Implications In The Daning-Jixian Block, Ordos Basin, Wang Chengwang, Zhang Yun, Wang Hongna, Chen Yiyu, Chen Gaojie, Wang Jun, Liu Lingqi, Li Panxue, He Hongcheng, Li Wenbiao
Components And Isotope Fractionation Of Deep Coalbed Methane And Their Geological Implications In The Daning-Jixian Block, Ordos Basin, Wang Chengwang, Zhang Yun, Wang Hongna, Chen Yiyu, Chen Gaojie, Wang Jun, Liu Lingqi, Li Panxue, He Hongcheng, Li Wenbiao
Coal Geology & Exploration
Objective The components of deep coalbed methane (CBM), along with its isotopic composition and fractionation patterns, hold great significance for revealing the genetic types, occurrence characteristics, flow, and production patterns of CBM. Methods This study investigated the Shanxi and Benxi formations in the Daning-Jixian block, Ordos Basin. A range of analyses and tests were conducted, including field CBM desorption experiments on coal samples from the deep parts of both formations, continuous monitoring of wellhead gas from two production wells, physical property tests on the samples, organic petrological experiments, and geochemical analysis. Furthermore, this study analyzed the components and isotopes of …
Investigating The Characteristics Of Ch4 Adsorption In Coal Reservoirs Based On Interpretable Machine Learning, Chen Ruibin, Zhou Sandong, Zhang Weixin, Yan Detian, Wang Hua
Investigating The Characteristics Of Ch4 Adsorption In Coal Reservoirs Based On Interpretable Machine Learning, Chen Ruibin, Zhou Sandong, Zhang Weixin, Yan Detian, Wang Hua
Coal Geology & Exploration
Objective Accurately predicting methane (CH4) adsorption capacity in coal reservoirs is critical to the efficient exploration and exploitation of coalbed methane (CBM). Existing studies largely rely on experimental data from a small number of samples and theoretical adsorption models such as Langmuir. However, these studies exhibit time-consuming and laborious processes, as well as conclusions with limited generalizability, posing challenges to their widespread applications across different basins. Methods Based on 1150 sets of experimental data on CH4 adsorption in coals, this study investigated five machine learning models, namely artificial neural network (ANN), support vector machine (SVM), K-nearest neighbor …
Fracturing With Three-Dimensional Full-Scale Fracture Network Propping For Deep Coalbed Methane Reservoirs: A Novel Ceramic Micro-Proppant And Its Verification Through Numerical Simulations, Li Xiang, Xu Jun, Li Ting, Zhang Xiaoyu, Yang Bo
Fracturing With Three-Dimensional Full-Scale Fracture Network Propping For Deep Coalbed Methane Reservoirs: A Novel Ceramic Micro-Proppant And Its Verification Through Numerical Simulations, Li Xiang, Xu Jun, Li Ting, Zhang Xiaoyu, Yang Bo
Coal Geology & Exploration
Objective and Methods Conventional fracturing struggles to achieve the long-term effective propping of complex fracture networks during the development of deep coalbed methane (CBM) reservoirs. To address this challenge, this study developed a novel ceramic micro-proppant suitable for the volumetric microfracture propping and, through numerical simulations, verified its performance when it was applied to reservoir stimulation in conjunction with the technology of fracturing with three-dimensional full-scale fracture network propping. First, a novel ceramic micro-proppant with a core-shell structure was designed according to the requirements of microfracture propping. Its key properties, including compressive strength, settling behavior, hydraulic conductivity, and stability, were …
A Spatiotemporal Surrogate Model And Multi-Objective Optimization For Multi-Well Coalbed Methane Production, Qin Yuancheng, Wang Mengyi, Wang Yanfeng, Li Yuan, He Bo, Fang Junling, Duan Qingshan, Liu Chen
A Spatiotemporal Surrogate Model And Multi-Objective Optimization For Multi-Well Coalbed Methane Production, Qin Yuancheng, Wang Mengyi, Wang Yanfeng, Li Yuan, He Bo, Fang Junling, Duan Qingshan, Liu Chen
Coal Geology & Exploration
Objective and Methods In the full-lifecycle optimization of multi-well and long-term coalbed methane (CBM) production, conventional numerical simulation methods face challenges including extremely high computational costs and difficult multi-objective trade-offs. To address these issues, this study proposed a spatiotemporal surrogate model for multi-objective optimization of CBM production. First, a heterogeneous reservoir model involving 17 production wells was constructed based on high-fidelity numerical simulation, and a sample dataset was created by applying random perturbations to the baseline production scheme. Second, a hybrid surrogate model integrating a convolutional neural network (CNN) and a Transformer decoder was established. The CNN was utilized for …
Stable Isotope-Based Origin Identification And Enrichment Zone Division Of Medium- To Low-Rank Coalbed Methane, Wang Qiong, Xu Fengyin, Ren Pengfei, Xu Hao, Lu Pengda, Hu Han, Zhou Siyuan
Stable Isotope-Based Origin Identification And Enrichment Zone Division Of Medium- To Low-Rank Coalbed Methane, Wang Qiong, Xu Fengyin, Ren Pengfei, Xu Hao, Lu Pengda, Hu Han, Zhou Siyuan
Coal Geology & Exploration
Objective Medium-to low-rank coalbed methane (CBM) exhibits complex origins with significant vertical differentiation, leading to unclear origin identification and enrichment patterns. This study aims to determine the genetic mechanisms, enrichment patterns, and efficient exploitation pathways of medium- to low-rank CBM. This will help improve the theoretical system for the exploration and exploitation of such CBM. Methods CBM data from 14 typical low- to medium-rank coalfields and coal-bearing basins across the world were comprehensively analyzed, including CBM compositions C1/(C2+C3), carbon and hydrogen isotopes of CH4 (δ13C-CH4 and δD-CH4 …
Dynamic-To-Static Elastic Parameter Conversion Models For Coals Under Temperature-Pressure Coupling: A Case Study Of The No. 8 Coal Seam In The Daning-Jixian Block, Zhang Wei, Wu Peng, Liu Conghui, Zhang Sidun, Sun Xuedong, Yang Haixing, Ma Zhuang, Shi Rui, Shen Jian
Dynamic-To-Static Elastic Parameter Conversion Models For Coals Under Temperature-Pressure Coupling: A Case Study Of The No. 8 Coal Seam In The Daning-Jixian Block, Zhang Wei, Wu Peng, Liu Conghui, Zhang Sidun, Sun Xuedong, Yang Haixing, Ma Zhuang, Shi Rui, Shen Jian
Coal Geology & Exploration
Objective Existing dynamic-to-static elastic parameter conversion models for coals fail to fully account for the actual in situ pressure and temperature conditions of deep reservoirs. This leads to significant deviations in directly evaluating the mechanical properties of reservoirs using log-derived dynamic parameters. To address this challenge, this study investigated dynamic-to-static elastic parameter conversion under the in situ stress and geotemperature conditions of strata. Accordingly, high-precision parameter conversion models were established. Methods This study examined coal samples from the No. 8 coal seam at a burial depth of approximately 1200 m in the Daning-Jixian block along the eastern margin of the …
3d Geological Modeling And Its Application For Steeply Dipping Coal Seams In The Miquan Area, Xinjiang, Wu Luofei, Li Yong, Zhang Weiqi, Han Yiyang, Zhang Jie, Cao Mingliang, Li Qiang
3d Geological Modeling And Its Application For Steeply Dipping Coal Seams In The Miquan Area, Xinjiang, Wu Luofei, Li Yong, Zhang Weiqi, Han Yiyang, Zhang Jie, Cao Mingliang, Li Qiang
Coal Geology & Exploration
Background Influenced by multi-stage compression from the North Tianshan and Bogda mountains, the southern margin of the Junggar Basin in Xinjiang exhibits the widespread development of steeply dipping coal seams. The extreme stratigraphic occurrence, combined with complex structural superimposition styles, poses significant challenges to the fine-scale characterization of these coal seams. Correspondingly, the planar and regional distribution patterns of gas content in these coal seams remain poorly understood, rendering it difficult to effectively determine the sweet spots of coalbed methane (CBM). Methods Focusing on the Miquan area, Xinjiang, this study investigated the methodology for 3D geological modeling of representative steeply …
A Seismic Prediction Technology For Coalbed Methane Sweet Spots And Its Engineering Application In The Ordos Basin, Zhang Mengbo, Li Fei, Zhang Dong, Peng Jiankang, Cui Xiaojie, Ni Na, Long Shengfang, Tao Yu, Zhu Jun
A Seismic Prediction Technology For Coalbed Methane Sweet Spots And Its Engineering Application In The Ordos Basin, Zhang Mengbo, Li Fei, Zhang Dong, Peng Jiankang, Cui Xiaojie, Ni Na, Long Shengfang, Tao Yu, Zhu Jun
Coal Geology & Exploration
Objective Deep coalbed methane (CBM) reservoirs tend to exhibit significant tuning effects of thin interbeds, leading to challenging localization of actual coal seam boundaries, limited identification accuracy of micro-amplitude structures in the coal seam roof, and poor stability of the seismic responses of the reservoirs' gas-bearing properties. To address these challenges, this study investigated the No. 8 coal seam of the Benxi Formation in the Mizhi area, Ordos Basin. Accordingly, a method with the prediction of gas-bearing properties as the primary controlling factor was developed for the seismic prediction and comprehensive evaluation of CBM sweet spots. Methods First, the actual …
Co2 Fracturing Stimulation Technology For Low-Yield Directional Coalbed Methane Wells And Its Applications, Zhang Junsheng, Cao Yunxing, Wang Li, Wang Zhongbin, Yang Baige, Shi Bin, Cao Yongsen, Xu Fengyi
Co2 Fracturing Stimulation Technology For Low-Yield Directional Coalbed Methane Wells And Its Applications, Zhang Junsheng, Cao Yunxing, Wang Li, Wang Zhongbin, Yang Baige, Shi Bin, Cao Yongsen, Xu Fengyi
Coal Geology & Exploration
Background In China, low-yield coalbed methane (CBM) wells represent a high proportion of approximately 57% (over 12400 wells), generally encountering challenges such as low pressure, dry reservoirs, and near-wellbore formation damage and blockage. Conventional hydraulic fracturing is prone to induce water blocking damage, while treatments such as acidification offer only limited blockage-removing radii. Therefore, existing techniques are insufficient to achieve blockage removal and permeability enhancement while avoiding reservoir damage. Exploring efficient waterless stimulation technologies suitable for these low-yield wells is of great significance for increasing CBM production and advancing the CBM industry. Methods This study investigated directional wells PXC-03 and …
Industrial Development Of Coalbed Methane Exploitation In China: A 30-Year Retrospective And Future Prospects, Meng Shangzhi, Li Yong, Qin Yong, Li Guofu, Tang Shuheng, Xu Fengyin, Wang Yanbin, Zhang Shouren, Zhang Cong
Industrial Development Of Coalbed Methane Exploitation In China: A 30-Year Retrospective And Future Prospects, Meng Shangzhi, Li Yong, Qin Yong, Li Guofu, Tang Shuheng, Xu Fengyin, Wang Yanbin, Zhang Shouren, Zhang Cong
Coal Geology & Exploration
Background The founding of China United Coalbed Methane Corp., Ltd. in 1996 signals the entry of the coalbed methane (CBM) exploitation in China into the industrial development stage. A systematic summary of the development history, key technologies, and future trends of China's CBM industry is of great significance for gaining a deeper understanding of CBM exploitation patterns and promoting the high-quality development of the CBM industry. Based on a systematic investigation of relevant domestic and international literature, this study presents a comprehensive analysis of the industrial development process of CBM exploitation in China, including development stages, technological evolution, and future …
Advances And Prospects Of Design Optimization Technologies For Differential Development With Three-Dimensional Well Patterns For Deep Coalbed Methane Reservoirs: A Case Study Of The No. 8 Coal Seam In The Ordos Basin, Yan Xia, Fang Jianlong, Mou Chun, Meng Peilong, Wang Yuan, Yu Xiang, Fei Shixiang, Feng Yanqing, Zhao Longmei, Li Meng, Cui Yuehua, Chi Runlong, Yang Qing, Huang Li, Zheng Xiaopeng, Yin Zesong, Wang Congcong, Ma Limin, Zhang Shuang, Liu Shirui, Zhang Yang, Guo Jiali
Advances And Prospects Of Design Optimization Technologies For Differential Development With Three-Dimensional Well Patterns For Deep Coalbed Methane Reservoirs: A Case Study Of The No. 8 Coal Seam In The Ordos Basin, Yan Xia, Fang Jianlong, Mou Chun, Meng Peilong, Wang Yuan, Yu Xiang, Fei Shixiang, Feng Yanqing, Zhao Longmei, Li Meng, Cui Yuehua, Chi Runlong, Yang Qing, Huang Li, Zheng Xiaopeng, Yin Zesong, Wang Congcong, Ma Limin, Zhang Shuang, Liu Shirui, Zhang Yang, Guo Jiali
Coal Geology & Exploration
Objective Design optimization for gas reservoir development serves as a key approach to the efficient exploitation, enhanced primary recovery, and elevated efficiency with reduced costs of deep coalbed methane (CBM). Methods In this study, the most extensively developed Ordos Basin in China was investigated as an example to explore the significant heterogeneity of the geological conditions of deep coal seams. Based on a fine-scale geological investigation of over 3 000 wells across the basin, this study systematically revealed the heterogeneity of the key parameters of deep coal reservoirs, including reservoir distribution, reservoir-cap rock assemblages, coal seam structure, and gas-bearing properties. …
Parameter Optimization And Field Application Of Roof Volume Fracturing Using Horizontal Wells For Coalbed Methane Extraction From Broken-Soft Coal Seams, Zhang Qingli, Sun Siqing, Li Haozhe, Wu Xiaoxuan, Yang Fan, Zheng Yuqi, Li Wenbo
Parameter Optimization And Field Application Of Roof Volume Fracturing Using Horizontal Wells For Coalbed Methane Extraction From Broken-Soft Coal Seams, Zhang Qingli, Sun Siqing, Li Haozhe, Wu Xiaoxuan, Yang Fan, Zheng Yuqi, Li Wenbo
Coal Geology & Exploration
Objective and Method To achieve rapid coalbed methane (CBM) extraction from broken-soft coal seams using surface horizontal wells, this study proposed a volume fracturing technology for coal seam roof using horizontal wells. Focusing coal seam 4-1 in a mining area, this study established a numerical model using finite element analysis (FEA) software Abaqus Using this model, the impacts of in-situ stress on the cross-layer propagation characteristics of multiple fractures were investigated. Through true triaxial hydraulic fracturing experiments, the multi-fracture propagation patterns under varying injection rates of fracturing fluids, perforation cluster numbers, and cluster spacings were analyzed. Using 3D fracturing design …
Advances In Research On Mechanisms And Prevention And Control Technologies For Solid-Phase Production In Hydraulically Fractured Coalbed Methane Wells, Zhang Fengsan, Wu Jinqiao, Lin Jin, Li Yu, Zhang Ying, Li Bing, Zhang Guobiao, Sun Ying, Gan Yuke
Advances In Research On Mechanisms And Prevention And Control Technologies For Solid-Phase Production In Hydraulically Fractured Coalbed Methane Wells, Zhang Fengsan, Wu Jinqiao, Lin Jin, Li Yu, Zhang Ying, Li Bing, Zhang Guobiao, Sun Ying, Gan Yuke
Coal Geology & Exploration
Background The effective coalbed methane (CBM) exploitation using hydraulic fracturing wells is severely constrained by two major solid-phase production issues: coal fines blockage and proppant flowback. The mechanisms behind both issues are associated with complex interplays between geological conditions and engineering disturbances. This study presents a systematic review of the current status of domestic and international research on the mechanisms of the solid-phase production, as well as relevant prevention and control methods. Furthermore, future research directions are proposed.Advances The solid-phase production in hydraulically fractured CBM wells essentially arises from flow-solid-chemical multi-field coupling processes under interplays between geological conditions and …
Enrichment Patterns And Accumulation Models Of Coalbed Methane Under Complex Geological Conditions: A Case Study Of The Xintian Coal Mine In Western Guizhou Province, China, Xu Shuai, Wu Caifang, Bie Xiaofei, Li Guangsheng, Fang Xiaojie, Wang Fangfang, Cheng Yi, Zhao Peng
Enrichment Patterns And Accumulation Models Of Coalbed Methane Under Complex Geological Conditions: A Case Study Of The Xintian Coal Mine In Western Guizhou Province, China, Xu Shuai, Wu Caifang, Bie Xiaofei, Li Guangsheng, Fang Xiaojie, Wang Fangfang, Cheng Yi, Zhao Peng
Coal Geology & Exploration
Objective The Xintian Coal Mine, a critical coal-producing mine in western Guizhou Province, faces high risks of coal and gas outbursts and the challenge of low underground coalbed methane (CBM) extraction efficiency, necessitating surface CBM extraction. However, the complex geological conditions in the area limit well placement and the fracturing and gas drainage effectiveness. Therefore, there is an urgent need to systematically elucidate the occurrence characteristics and enrichment patterns of CBM in the area.Methods Based on data from exploration boreholes in the Xintian Coal Mine, combined with experiment and test results and log interpretations, this study revealed the physical …
Differences In Gas-Bearing Properties Of Deep And Shallow Coal Reservoirs And Their Implications For Coalbed Methane Production In The Western Section Of The Southern Margin Of The Junggar Basin, Xinjiang, Mi Julei, Zhao Changyong, Yang Zhaobiao, Wang Pengli, Li Erting, Zhang Baoxin, Bai Haifeng, Gao Xiuwei, Wang Jianan
Differences In Gas-Bearing Properties Of Deep And Shallow Coal Reservoirs And Their Implications For Coalbed Methane Production In The Western Section Of The Southern Margin Of The Junggar Basin, Xinjiang, Mi Julei, Zhao Changyong, Yang Zhaobiao, Wang Pengli, Li Erting, Zhang Baoxin, Bai Haifeng, Gao Xiuwei, Wang Jianan
Coal Geology & Exploration
Background In recent years, breakthroughs have been constantly achieved in the production of coalbed methane (CBM) at burial depths exceeding 2 000 m in China, with the gas-bearing properties of coal reservoirs identified as a primary geological parameter controlling the CBM production. The western section of the southern margin of the Junggar Basin (also referred to as the study area) hosts abundant CBM resources. In this section, the burial depths of extensive coal seams exceed 2 000 m. However, limited explorations of deep coal reservoirs have restricted a systematic understanding of the gas-bearing properties of coal reservoirs in the study …
Log-Based Identification Of Sedimentary Facies In Coal Measures In The Southern Wuxiang Block, Shanxi Province, China, Jin Yi, Tian Yunqing, Song Huibo, Hu Bin, Yu Zhenfeng
Log-Based Identification Of Sedimentary Facies In Coal Measures In The Southern Wuxiang Block, Shanxi Province, China, Jin Yi, Tian Yunqing, Song Huibo, Hu Bin, Yu Zhenfeng
Coal Geology & Exploration
Objective The Carboniferous and Permian coal-bearing strata in the southern Wuxiang block, Qinshui Basin, Shanxi Province, China contain abundant coalbed methane (CBM) resources. To develop intelligent discrimination technology for CBM exploration in this block, it is necessary to establish lithology discrimination criteria based on log data, reveal the response relationships between logging and sedimentary facies, and determine sedimentary patterns. Methods Using a comprehensive analysis of lithologies, sedimentary facies, and logging facies, this study systematically investigated the distributions of logging and sedimentary facies in the Shanxi and Taiyuan formations—the primary coal-bearing strata in the southern Wuxiang block. By comprehensively analyzing the …
Current Status And Future Trends Of Seismic Prediction And Assessment Technology For Coalbed Methane Reservoirs, Wu Haibo, Zhang Pingsong, Xu Shi’Ang, Huang Yaping, Dong Shouhua, Cheng Yan, Li Donghui, Zhang Sheng, Zhang Min
Current Status And Future Trends Of Seismic Prediction And Assessment Technology For Coalbed Methane Reservoirs, Wu Haibo, Zhang Pingsong, Xu Shi’Ang, Huang Yaping, Dong Shouhua, Cheng Yan, Li Donghui, Zhang Sheng, Zhang Min
Coal Geology & Exploration
Background The seismic prediction and assessment technology for coalbed methane (CBM) reservoirs has undergone rapid development for over three decades, playing an indispensable role in CBM exploration. Methods This study reviews the development history and current status of core technologies within the seismic prediction and assessment technical system for CBM reservoirs, including seismic-petrophysical tests, modeling and inversion, seismic wavefield simulation, seismic amplitude versus offset (AVO) inversion and seismic attribute inversion, and integrated seismic prediction of the sweet spot areas of CBM reservoir resources and engineering. Furthermore, this study delves into the impacts and limitations of the characteristics of CBM reservoirs, …
Analyzing The Permeability Enhancement Effect Of Hydraulic Slotting For Low-Permeability Coal Seams Based On A Stress-Diffusion-Seepage Coupling Model, Zhang Hongtu, Zhou Tian, Wang Dengke, Li Botao, Luo Yong, Pan Rongsheng, Tang Jiahao, Lu Weiyong
Analyzing The Permeability Enhancement Effect Of Hydraulic Slotting For Low-Permeability Coal Seams Based On A Stress-Diffusion-Seepage Coupling Model, Zhang Hongtu, Zhou Tian, Wang Dengke, Li Botao, Luo Yong, Pan Rongsheng, Tang Jiahao, Lu Weiyong
Coal Geology & Exploration
Objective and Methods This study aims to improve the permeability enhancement effect of coal seams for gas drainage. Targeting the soft, low-permeability coal seams with complex gas occurrence conditions in the Baiping mining area and considering the impacts of effective stress, gas migration, actual gas effects, and tortuosity, this study constructed a stress-diffusion-seepage coupling model based on the pore-fracture dual medium assumption. Using the coupling model, this study simulated the variation patterns of gas content in coal seams during gas drainage under varying gas contents and borehole spacings. Through field tests under different permeability enhancement measures and unloaded coal amounts …
Optimization And Application Of Sand Bailing Technology For Coalbed Methane Horizontal Wells, Zhang Fei, Wang Yibing, Cheng Lu, Mei Wenbo, Yang Qi, Shen Wenjie, Cao Chao, Lai Peng, Liao Zhengkai, Xian Bao'an, Bi Yansen
Optimization And Application Of Sand Bailing Technology For Coalbed Methane Horizontal Wells, Zhang Fei, Wang Yibing, Cheng Lu, Mei Wenbo, Yang Qi, Shen Wenjie, Cao Chao, Lai Peng, Liao Zhengkai, Xian Bao'an, Bi Yansen
Coal Geology & Exploration
Objective and Methods Coalbed methane (CBM) horizontal wells face challenges such as sand accumulation in completion strings, pipe wall scaling, and pump sticking, leading to declined CBM production or shutdown of these wells. This severely restricts continuous, stable CBM production. Removing pulverized coals and sands from wellbores through mechanical sand bailing is recognized as an effective technique to restore and improve the CBM production of horizontal wells. To address challenges such as poor string sealing performance, low efficiency, and sand consolidation in mechanical sand bailing, this study created optimized tools including claw-shaped scraper tips, sand-breaking drill bits, eccentric flaps, and …
Distributed Optical Fiber Acoustic Sensing-Based Optimization Of Microseismic Source Localization In The Hydraulic Fracturing For Coalbed Methane Production, Hua Hao, Cheng Bingjie, Xu Tianji, Yan Zhenqian, Gao Bo, He Cheng
Distributed Optical Fiber Acoustic Sensing-Based Optimization Of Microseismic Source Localization In The Hydraulic Fracturing For Coalbed Methane Production, Hua Hao, Cheng Bingjie, Xu Tianji, Yan Zhenqian, Gao Bo, He Cheng
Coal Geology & Exploration
Objective To achieve safe and efficient hydraulic fracturing, it is necessary to conduct timely and accurate microseismic monitoring in the reservoir stimulation process. The purpose is to analyze and assess the fracturing effects. Methods Using a permanently deployed fiber-optic cable outside the casing of a coalbed methane (CBM) well, this study employed distributed optical fiber acoustic sensing (DAS)for full-borehole, wide-azimuth, and high-density real-time monitoring of microseismic events induced by the hydraulic fracturing of coal seams. Furthermore, this study proposed a novel method for localizing microseismic sources based on information about wave travel time and a source-constrained mapping algorithm. First, effective …
Factors Influencing The Production Of Coalbed Methane From Deep Reservoirs, Wang Zhenzhi, Fu Xuehai, Pan Jienan, Jin Yi, Wang Haichao
Factors Influencing The Production Of Coalbed Methane From Deep Reservoirs, Wang Zhenzhi, Fu Xuehai, Pan Jienan, Jin Yi, Wang Haichao
Coal Geology & Exploration
Objective The production characteristics of coalbed methane (CBM) from deep reservoirs differ significantly from those of CBM from shallow reservoirs. Key challenges in deep CBM production include maintaining reservoir permeability or minimizing permeability loss, enhancing CBM (CH4) desorption efficiency, and accurately predicting the laws of CH4 diffusion. There is an urgent need to overcome these challenges through technological innovation and theoretical research. Methods This study systematically analyzed the advances in domestic and international research on coal reservoir permeability, CBM desorption, and CBM diffusion. By integrating the classification of production stages of deep coal reservoirs with the dominant …
China’S Cbm Exploration And Production And Associated Technological Advancements: A Review And Reflections, Ye Jianping
China’S Cbm Exploration And Production And Associated Technological Advancements: A Review And Reflections, Ye Jianping
Coal Geology & Exploration
Objective and Methods Based on extensive scientific and technical literature and technical data on coalbed methane (CBM) exploration and production projects, this study conducted a comparative analysis of the development process and latest advances in China’s critical technologies for CBM exploration and production and reviewed the CBM exploration and production history of this country over the past three decades. Accordingly, this study discussed the theoretical and technical challenges in CBM exploration and production and proposed future development directions. Advances The results indicate that the insights into conversion between adsorbed and free deep CBM prove to be a significant theoretical understanding. …
A Preliminary Study Of Coalbed Methane Adsorption At Fractal Interfaces, Jin Yi, Li Yani, Song Huibo, Zhao Mengyu, Yang Yunhang, Chen Zenan
A Preliminary Study Of Coalbed Methane Adsorption At Fractal Interfaces, Jin Yi, Li Yani, Song Huibo, Zhao Mengyu, Yang Yunhang, Chen Zenan
Coal Geology & Exploration
The adsorption and desorption mechanisms of coalbed methane (CBM) are foundational for revealing CBM accumulation mechanisms and achieving efficient CBM exploitation. Studies have indicated that coal reservoirs exhibit complex pore structures with fractal features, significantly influencing CBM adsorption at pore-solid interfaces. Based on a comparative analysis of several common adsorption models for gas-solid interfaces and a summary of their characteristics and applicable conditions, this study suggests that all these adsorption models still rely on the stationary assumption of adsorption selectivity for the description and application of CBM adsorption behavior at fractal interfaces while overlooking the scale invariance of the adsorption …
Potential For The Production Of Deep To Ultradeep Coalbed Methane Resources In The Upper Permian Longtan Formation, Sichuan Basin, Ming Ying, Sun Haofei, Tang Dazhen, Xu Liang, Zhang Benjian, Chen Xiao, Xu Chang, Wang Jiaxian, Chen Shida
Potential For The Production Of Deep To Ultradeep Coalbed Methane Resources In The Upper Permian Longtan Formation, Sichuan Basin, Ming Ying, Sun Haofei, Tang Dazhen, Xu Liang, Zhang Benjian, Chen Xiao, Xu Chang, Wang Jiaxian, Chen Shida
Coal Geology & Exploration
Breakthroughs have been achieved in the high-yield gas flow of coalbed methane (CBM) wells with burial depths ranging from 1000 to 2500 m in the Cainan area of the Junggar Basin and the Daning-Jixian and southern Yanchuan blocks on the eastern margin of the Ordos Basin, signifying the enormous potential for the production of deep CBM. In the Sichuan Basin, the thin to moderately thick coal seam groups (7‒15 layers) in the Upper Permian Longtan Formation primarily exhibit burial depths ranging between 2000 and 4500 m. In the central Sichuan Basin, characterized by north-dipping monoclines and local low-amplitude uplifts, deep …
Present Situation And Technical Research Progress Of Coalbed Methane Surface Development In Coal Mining Areas Of China, Zhang Qun, Jiang Wenping, Jiang Zaibing, Sun Siqing, Li Bingang, Du Xinfeng, Wu Xiuping, Zhao Jizhan, Fan Yao, Fan Zhangqun, Han Baoshan, Xu Yaobo, Liu Baigen
Present Situation And Technical Research Progress Of Coalbed Methane Surface Development In Coal Mining Areas Of China, Zhang Qun, Jiang Wenping, Jiang Zaibing, Sun Siqing, Li Bingang, Du Xinfeng, Wu Xiuping, Zhao Jizhan, Fan Yao, Fan Zhangqun, Han Baoshan, Xu Yaobo, Liu Baigen
Coal Geology & Exploration
The exploration and development process of coalbed methane (CBM) in coal mining areas, which was implemented under the organization and cooperation of the coal enterprises in China, was reviewed in this paper. After more than 30 years of hard work and unremitting efforts, gratifying achievements have been made in the research, engineering experiments and industrial development on CBM surface development technology, including the successful CBM development of anthracite coal in Jincheng mining area, Shanxi Province, for the first time at home and abroad, the largescale commercial production of CBM, the major breakthrough made in the CBM development technology by horizontal …
Typical Coalbed Methane (Cbm) Enrichment And Production Modes Under The Control Of Regional Structure And Evolution, Ju Yiwen, Qiao Peng, Wei Mingming, Li Xin, Xu Fengyin, Feng Guorui, Li Yong, Wu Caifang, Cao Yunxing, Li Guofu, Han Yuming, Li Zhen, Lu Zhigang, Jiang Lei
Typical Coalbed Methane (Cbm) Enrichment And Production Modes Under The Control Of Regional Structure And Evolution, Ju Yiwen, Qiao Peng, Wei Mingming, Li Xin, Xu Fengyin, Feng Guorui, Li Yong, Wu Caifang, Cao Yunxing, Li Guofu, Han Yuming, Li Zhen, Lu Zhigang, Jiang Lei
Coal Geology & Exploration
Coalbed methane (CBM) exploration and development is of great significance to optimize China’s energy structure and cope with coal mine disasters and ecological environment problems. In this paper, combined with regional structure and evolution and CBM geological conditions, the enrichment and recovery modes of CBM are innovatively divided into four categories: simple structural fracture system, fold system (shallower synclinal shaft, fold limb, secondary structural high position), thrust system (fault-thrust-fold belt, high-steep thrust structure) and structural superposition system. Among them, simple structural fracture system mode is often encountered in the areas with relatively stable structure, where the CBM is mainly derived …
Reservoir Forming Characteristics And Favorable Area Evaluation Of Deep Coalbed Methane In Daning-Jixian Block, Li Shuguang, Wang Chengwang, Wang Hongna, Wang Yubin, Xu Fengyin, Guo Zhidong, Liu Xinwei
Reservoir Forming Characteristics And Favorable Area Evaluation Of Deep Coalbed Methane In Daning-Jixian Block, Li Shuguang, Wang Chengwang, Wang Hongna, Wang Yubin, Xu Fengyin, Guo Zhidong, Liu Xinwei
Coal Geology & Exploration
The No.8 coal with a buried depth of more than 2 000 m of Lower Permian Taiyuan Formation in Daning-Jixian block, eastern margin of Ordos Basin is the first deep CBM field with an output of 100 billion m3 in China, but the reservoir forming characteristics of deep CBM are still unclear. In this paper, geological information, test and production data are synthetically applied to study the characteristics of deep CBM reservoir formation and evaluation of favorable areas. The results show that the deep coal reservoir in the study area is extensively distributed, with large thickness and high degree …
Geological Adaptability Analysis And Operational Parameter Optimization For Staged Fracturing Horizontal Wells In Coal Seam Roof, Jiang Zaibing, Li Haozhe, Xu Yaobo, Zhang Qun, Li Guihong, Fan Yao, Jiang Wenping, Shu Jiansheng, Pang Tao, Cheng Bin
Geological Adaptability Analysis And Operational Parameter Optimization For Staged Fracturing Horizontal Wells In Coal Seam Roof, Jiang Zaibing, Li Haozhe, Xu Yaobo, Zhang Qun, Li Guihong, Fan Yao, Jiang Wenping, Shu Jiansheng, Pang Tao, Cheng Bin
Coal Geology & Exploration
The technique of staged fracturing horizontal wells in coal seam roof is effective for efficient extraction of coalbed methane (CBM) in broken soft and low-permeability coal seams. With the help of the major national science and technology projects of the 13th Five Year Plan for National Economic and Social Development, the efficient extraction technology of CBM by staged fracturing horizontal wells in coal seam roof was studied. By using theoretical analysis and numerical simulation, the fracture propagation patterns in different in-situ stress states were compared, and the influence of the angle between the horizontal well layout orientation and the minimum …