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Environmental Sciences

Coal Geology & Exploration

2024

Deep coalbed methane

Articles 1 - 14 of 14

Full-Text Articles in Engineering

Geochemical Characteristics And Influencing Factors Of Deep Coalbed Methane In The Linxing-Shenfu Block, Wu Peng, Hu Weiqiang, Li Yangbing, Ma Litao, Li Yong, Zhao Fei, Niu Yanwei, Chen Jianqi, Li Panpan, Liu Zaizhen, Li Chenchen, Cao Di, Liu Cheng May 2024

Geochemical Characteristics And Influencing Factors Of Deep Coalbed Methane In The Linxing-Shenfu Block, Wu Peng, Hu Weiqiang, Li Yangbing, Ma Litao, Li Yong, Zhao Fei, Niu Yanwei, Chen Jianqi, Li Panpan, Liu Zaizhen, Li Chenchen, Cao Di, Liu Cheng

Coal Geology & Exploration

Identifying the origin and geochemical characteristics of deep coalbed methane (CBM) is critical for its exploration and production. This study examined the desorbed gas from deep-CBM parameter wells in the Linxing-Shenfu block on the eastern margin of the Ordos Basin. It systematically tested the composition, content, and carbon isotopes of CBM in coal seams Nos. 8 and 9. In combination with the degree of thermal evolution, gas-bearing properties, coal seam burial depths, geological structures, and hydrogeologic conditions, it delved into the geochemical characteristics and influencing factors of deep CBM. The results show that the deep CBM in the study area …


Preliminarily Exploring The Theories And Technologies For Coalbed Methane Production Using Horizontal Wells: Comparison Of Conditions For Coalbed Methane And Shale Gas Exploitation, Wang Hongyan, Duan Yaoyao, Liu Honglin, Zhao Qun, Chen Shangbin, Lu Haibing, Shi Zhensheng, Sun Qinping, Chen Zhenhong, Zhou Shangwen, Yang Mingwei, Wang Cong Apr 2024

Preliminarily Exploring The Theories And Technologies For Coalbed Methane Production Using Horizontal Wells: Comparison Of Conditions For Coalbed Methane And Shale Gas Exploitation, Wang Hongyan, Duan Yaoyao, Liu Honglin, Zhao Qun, Chen Shangbin, Lu Haibing, Shi Zhensheng, Sun Qinping, Chen Zhenhong, Zhou Shangwen, Yang Mingwei, Wang Cong

Coal Geology & Exploration

Through 30 years of unremitting explorations, coalbed methane (CBM) wells in China have gradually transitioned from vertical to horizontal wells. However, the lack of basic theories on CBM production using horizontal wells is the main challenge to current CBM development. Compared to shales, coal seams exhibit heterogeneity and a minor presence of foliations and brittle minerals, hindering the formation of volumetric fracture networks. Nevertheless, the roofs and floors of coal seams have high sealing capacities and mechanical strength, creating excellent conditions for hydraulic fracturing. Some fractures in coals are filled with calcite, rendering acidification conducive to the improvement of reservoir …


Accumulation Characteristics And Exploration Prospects Of Deep Coalbed Methane In The Longtan Formation Of The Nanchuan Block On The Southeastern Margin Of The Sichuan Basin, Guo Tao, Jin Xiaobo, Wu Didi, Xie Fei, Liu Jinxian Apr 2024

Accumulation Characteristics And Exploration Prospects Of Deep Coalbed Methane In The Longtan Formation Of The Nanchuan Block On The Southeastern Margin Of The Sichuan Basin, Guo Tao, Jin Xiaobo, Wu Didi, Xie Fei, Liu Jinxian

Coal Geology & Exploration

Vertical well Y2 in the Nanchuan bloc on the southeastern margin of the Sichuan Basin has yielded daily production of natural flowing gas of 13000 m3, signifying a strategic breakthrough in deep coalbed methane (CBM) exploration on the margin. This study aims to systematically reveal the enrichment and high-yield patterns of CBM in the Nanchuan block. Using data on the regional geology, tests, assays, and production, this study investigated the accumulation characteristic and conducted exploration potential evaluation for deep CBM in the Nanchuan block from the perspective of the quality, pore and fissure characteristics, gas content, and fracability …


Outcomes And Implications Of Pilot Tests For Deep Coalbed Methane Production On The Eastern Margin Of The Ordos Basin, Nie Zhihong, Xu Fengyin, Shi Xiaosong, Xiong Xianyue, Song Wei, Zhang Lei, Liu Ying, Sun Wei, Feng Yanqing, Liu Shirui, Yan Xia, Sun Xiaoyi, Wu Mansheng Feb 2024

Outcomes And Implications Of Pilot Tests For Deep Coalbed Methane Production On The Eastern Margin Of The Ordos Basin, Nie Zhihong, Xu Fengyin, Shi Xiaosong, Xiong Xianyue, Song Wei, Zhang Lei, Liu Ying, Sun Wei, Feng Yanqing, Liu Shirui, Yan Xia, Sun Xiaoyi, Wu Mansheng

Coal Geology & Exploration

Breakthroughs in the exploration and production of deep coalbed methane (CBM) in the Daning-Jixian block on the eastern margin of the Ordos Basin exert a profound influence on the CBM industry, arousing extensive concern and follow-up. Although previous studies delved into the theoretical and technical challenges and corresponding solutions of deep CBM exploration and production, there is a lack a systematic summary of pilot tests for typical gas field exploitation. Through an in-depth dissection of the geological characteristics and challenges of cost-effective production of deep CBM, this study summarized the advances and outcomes of the pilot test projects in the …


Exploration And Exploitation Of Deep Coalbed Methane In The Baijiahai Uplift, Junggar Basin: Progress And Its Implications, Lan Hao, Yang Zhaobiao, Chou Peng, Wang Bin, Liu Changqing, Liang Yuhui, Wang Yuqiang Feb 2024

Exploration And Exploitation Of Deep Coalbed Methane In The Baijiahai Uplift, Junggar Basin: Progress And Its Implications, Lan Hao, Yang Zhaobiao, Chou Peng, Wang Bin, Liu Changqing, Liang Yuhui, Wang Yuqiang

Coal Geology & Exploration

The Jurassic coals in the Baijiahai uplift, with breakthroughs made in the deep coalbed methane (CBM) production of vertical wells in the early stage in China, serve as an important exploration target of the Junggar Basin. Their coal reservoirs feature an ultra-low ash content, a low moisture content, medium-to-high volatility, and favorable porosity and permeability systems. With gas accumulation modes, namely, the paleo-source and young-reservoir made and the self-source and self-reservoir mode, the coal seams enjoy favorable gas-bearing properties, such as a high gas content, a high proportion of free gas, and high gas saturation, which establish them as high-quality …


Deep Coalbed Methane Production Technology For The Eastern Margin Of The Ordos Basin: Advances And Their Implications, Zeng Wenting, Xu Fengyin, Zhang Lei, Sun Weiwei, Wang Qian, Liu Yinhua, Yu Lizhu, Ji Liang, Zeng Quanshu, Zhang Kang Feb 2024

Deep Coalbed Methane Production Technology For The Eastern Margin Of The Ordos Basin: Advances And Their Implications, Zeng Wenting, Xu Fengyin, Zhang Lei, Sun Weiwei, Wang Qian, Liu Yinhua, Yu Lizhu, Ji Liang, Zeng Quanshu, Zhang Kang

Coal Geology & Exploration

Contrasting with shallow to moderately deep coalbed methane (CBM) reservoirs, deep CBM reservoirs exhibit favorable coal structures, high formation pressure, high free gas ratios, and high contents of total dissolved solids (TDS) and CO2. Extensive fracturing allows for CBM flowing at the initial stage, while the production parameters vary significantly throughout the CBM production. This requires wide technological boundaries of the main production technologies. Compared to shale gas and tight gas, deep CBM manifests different production mechanisms and relatively low free gas ratios, which lead to short flowing cycles of CBM. This necessitates timely water withdrawal for CBM …


Occurrence Mechanism, Environment And Dynamic Evolution Of Gas And Water In Deep Coal Seams, Li Yong, Xu Lifu, Liu Yu, Wang Ziwei, Gao Shuang, Ren Ci Feb 2024

Occurrence Mechanism, Environment And Dynamic Evolution Of Gas And Water In Deep Coal Seams, Li Yong, Xu Lifu, Liu Yu, Wang Ziwei, Gao Shuang, Ren Ci

Coal Geology & Exploration

Accurately understanding of the occurrence states, relative content, and distribution characteristics of gas - water under deep conditions has important guiding significance for efficient exploration and development of coalbed methane (CBM). Based on the theoretical model, molecular simulation and systematic analysis of gas-water, the occurrence states of gas-water in coal seam is clarified, and the boundary and dynamic evolution process of gas-water dynamic migration and accumulation are revealed. Considering the coal - water interface interaction, the mobility and occurrence states of water, the coalbed water can be divided into movable water (gravity water and capillary water), bound water (adsorbed water, …


Effects Of Depth On Gas-Bearing Properties Of Coal Reservoirs And Their Coupling Relationships With Coalbed Methane Accumulation, Chen Shida, Hou Wei, Tang Dazhen, Li Xiang, Xu Hao, Tao Shu, Li Song, Tang Shuling Feb 2024

Effects Of Depth On Gas-Bearing Properties Of Coal Reservoirs And Their Coupling Relationships With Coalbed Methane Accumulation, Chen Shida, Hou Wei, Tang Dazhen, Li Xiang, Xu Hao, Tao Shu, Li Song, Tang Shuling

Coal Geology & Exploration

Burial depth serves as a comprehensive factor influencing coalbed methane (CBM) accumulation. Understanding the effects of depth on gas-bearing properties is critical for ascertaining the occurrence states and accumulation mechanisms of deep/shallow CBM. Based on the present situation of CBM exploration and the dissection of data from CBM exploration wells on the eastern margin of the Ordos Basin, this study explored the effects of burial depth on the gas content, saturated adsorbed gas capacity, and gas saturation of coal seams, as well as their coupling relationship with accumulation processes, using conventional and unconventional petroleum accumulation. The results indicate that CBM …


Deep Coalbed Methane Resources In The Shenmu-Jiaxian Block, Ordos Basin, China: Geological Characteristics And Potential For Exploration And Exploitation, Li Guoyong, Yao Yanbin, Wang Hui, Meng Lingjian, Li Peijie, Zhang Yongchao, Wang Jianwei, Ma Limin Feb 2024

Deep Coalbed Methane Resources In The Shenmu-Jiaxian Block, Ordos Basin, China: Geological Characteristics And Potential For Exploration And Exploitation, Li Guoyong, Yao Yanbin, Wang Hui, Meng Lingjian, Li Peijie, Zhang Yongchao, Wang Jianwei, Ma Limin

Coal Geology & Exploration

China boasts abundant coalbed methane (CBM) resources in deep layers (burial depths: greater than 2000 m), with considerable potential for CBM exploration and development. Compared to medium and shallow CBM, deep CBM differs significantly in enrichment and accumulation patterns and exploitation means. Therefore, there is an urgent need to dissect key CBM blocks. The Shenmu-Jiaxian block, situated in the northeastern Ordos Basin, is currently in the early stages of deep CBM exploration, with enrichment characteristics and exploration potential remaining undefined. Based on recently obtained seismic data, logging data from over 300 wells, and analytical results from four cored wells, this …


Enrichment And Accumulation Patterns And Favorable Area Evaluation Of Deep Coalbed Methane In The Fugu Area, Ordos Basin, Guo Guangshan, Xu Fengyin, Liu Lifang, Cai Yidong, Qin Wei, Chen Zhaohui, Deng Jimei, Li Zhuolun Feb 2024

Enrichment And Accumulation Patterns And Favorable Area Evaluation Of Deep Coalbed Methane In The Fugu Area, Ordos Basin, Guo Guangshan, Xu Fengyin, Liu Lifang, Cai Yidong, Qin Wei, Chen Zhaohui, Deng Jimei, Li Zhuolun

Coal Geology & Exploration

The Shenfu block on the eastern margin of the Ordos Basin is a typical deep coalbed methane (CBM) field with abundant resources and considerable potential for exploration and exploitation. In October 2023, the large-scale Shenfu deep CBM field successfully reported proven geological reserves exceeding 110 billion m3. The Fugu area, located in the central part of the Shenfu block, is the earliest experimental area for deep CBM production. However, there is a lack of a clear understanding of CBM enrichment and accumulation patterns, as well as the potential for exploration and development, of this area. By comprehensively utilizing …


Geological Characteristics And Favorable Area Evaluation Of Deep Coalbed Methane In Wangfu Fault Depression, Southern Songliao Basin, Shen Xia, Gong Haitao, Shao Mingli, Yang Minfang, Huo Wanguo Feb 2024

Geological Characteristics And Favorable Area Evaluation Of Deep Coalbed Methane In Wangfu Fault Depression, Southern Songliao Basin, Shen Xia, Gong Haitao, Shao Mingli, Yang Minfang, Huo Wanguo

Coal Geology & Exploration

The Wangfu fault depression in the southern Songliao Basin is rich in coalbed methane (CBM) resources. However, CBM exploration in this area has been restricted by the low-level exploration of deep CBM and a lack of systematic studies on the geological characteristics of CBM, primary factors controlling CBM enrichment and accumulation, and the selection of favorable targets. Therefore, based on the systematical analysis of the geological characteristics of coal-bearing strata, this study identified the major factors controlling deep CBM accumulation, established the index system for favorable area selection, and predicted the favorable areas of CBM enrichment. The results show that: …


A Calculation Model Of Free Gas Saturation In Deep Coalbed Methane Reservoirs And Its Application, Shi Juntai, Cao Jingtian, Xu Fengyin, Xiong Xianyue, Huang Hongxing, Sun Zheng, Jia Yanran, Ma Shurui, Zheng Haohang, Deng Ting, Li Jing, Li Xiangfang Feb 2024

A Calculation Model Of Free Gas Saturation In Deep Coalbed Methane Reservoirs And Its Application, Shi Juntai, Cao Jingtian, Xu Fengyin, Xiong Xianyue, Huang Hongxing, Sun Zheng, Jia Yanran, Ma Shurui, Zheng Haohang, Deng Ting, Li Jing, Li Xiangfang

Coal Geology & Exploration

In recent years, breakthroughs have been achieved in the exploration of deep coalbed methane (CBM) in China based on fine-scale geological research and techniques such as multistage hydraulic fracturing using proppants in a horizontal well. As a result, some wells yielded daily gas production of up to 100000 m3, inspiring confidence again in the CBM industry. However, since deep coal reservoirs occur in a complex geological environment characterized by high in-situ stress, high geotemperature, high pore pressure, and low permeability, there is an urgent need to reveal the typical parameters of coal reservoirs at different depths and the …


Multi-Round Diverting Fracturing Technology And Its Application In Deep Coalbed Methane In The Daning-Jixian Block, Xiong Xianyue, Zhen Huaibin, Li Shuguang, Wang Hongna, Zhang Lei, Song Wei, Lin Hai, Xu Fengyin, Li Zhongbai, Zhu Weiping, Wang Chengwang, Chen Gaojie Feb 2024

Multi-Round Diverting Fracturing Technology And Its Application In Deep Coalbed Methane In The Daning-Jixian Block, Xiong Xianyue, Zhen Huaibin, Li Shuguang, Wang Hongna, Zhang Lei, Song Wei, Lin Hai, Xu Fengyin, Li Zhongbai, Zhu Weiping, Wang Chengwang, Chen Gaojie

Coal Geology & Exploration

The Daning-Jixian block on the eastern margin of the Ordos Basin exhibits high-abundance deep coalbed methane (CBM) resources, well-developed natural fractures of coal reservoirs, well-developed cleats and fractures in coals themselves, coals with excellent structures and high mechanical strength, and strong sealing ability of coal roofs and floors. All these create favorable conditions for the formation of a large-scale fracture network through volume fracturing. The ultra-large-scale fracturing process has contributed to a major breakthrough in the single-well output of deep CBM. However, the tracer monitoring results show that various fracturing stages of horizontal wells exhibited different contribution rates to gas …


Deep Coal Reservoirs In The Ningwu Basin: Geothermal Field Characteristics And Their Effects On Gas-Bearing Properties, Xi Zhaodong, Tang Shuheng, Liu Zhong, Qu Xiaorong, Zhang Pengbao, Su Yufei, Zhang Qian Feb 2024

Deep Coal Reservoirs In The Ningwu Basin: Geothermal Field Characteristics And Their Effects On Gas-Bearing Properties, Xi Zhaodong, Tang Shuheng, Liu Zhong, Qu Xiaorong, Zhang Pengbao, Su Yufei, Zhang Qian

Coal Geology & Exploration

Temperature acts as an important factor affecting the gas-bearing properties of deep coal reservoirs, further affecting the development performance of deep coalbed methane (CBM). Therefore, ascertaining the geothermal conditions of coal reservoirs and their effects on the gas-bearing properties of deep coal reservoirs is critical to the systemic understanding of the enrichment characteristics and production patterns of deep CBM. For coal seam No.9 in the Taiyuan Formation within the Ningwu Basin, over 90% of the area has burial depths exceeding 1000 m. In the hinterland of the basin, coal seams generally exhibit burial depths greater than 1500 m, with a …