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Full-Text Articles in Physical Sciences and Mathematics
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
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
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
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
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
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
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
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
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
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
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
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
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
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 …
Theoretical And Technological Difficulties And Countermeasures Of Deep Cbm Exploration And Development In The Eastern Edge Of Ordos Basin, Xu Fengyin, Yan Xia, Li Shuguang, Xiong Xianyue, Wang Yuxin, Zhang Lei, Liu Chuanqing, Han Jinliang, Feng Yanqing, Zhen Huaibin, Yang Yun, Wang Chengwang, Li Yuxin
Theoretical And Technological Difficulties And Countermeasures Of Deep Cbm Exploration And Development In The Eastern Edge Of Ordos Basin, Xu Fengyin, Yan Xia, Li Shuguang, Xiong Xianyue, Wang Yuxin, Zhang Lei, Liu Chuanqing, Han Jinliang, Feng Yanqing, Zhen Huaibin, Yang Yun, Wang Chengwang, Li Yuxin
Coal Geology & Exploration
Deep coalbed methane (CBM) resources (hereinafter referred to the CBM resources with the buried depth greater than 2 000 m) are abundant in China and have great potential in exploration and development. Since 2019, Daning‒Jixian block in the eastern edge of Ordos Basin has entered the stage of "scaled exploration + pilot test" of deep CBM, with the daily gas production exceeding 2 × 104 m 3in vertical wells and 10 × 104 m 3in horizontal wells. This remarkable achievement has broken through the traditional depth limitation in CBM exploration and development. Thus,the total resource of …
Acid Fracturing Technology Of Deep Cbm Wells And Its Field Test In Daning-Jixian Block, Liu Changsong, Zhao Haifeng, Chen Shuai, Zhen Huaibin, Wang Chengwang
Acid Fracturing Technology Of Deep Cbm Wells And Its Field Test In Daning-Jixian Block, Liu Changsong, Zhao Haifeng, Chen Shuai, Zhen Huaibin, Wang Chengwang
Coal Geology & Exploration
There are abundant deep coalbed methane resources in China, but the coupling problem of coal reservoir reconstruction technology and deep geological quality conditions needs to be solved urgently. With Daning-Jixian Block as the geological background, the feasibility of volumetric fracturing is evaluated from the perspective of rock mechanical parameters of the No.8 coal seam in a deep layer of the block, and verified by the indoor triaxial acid fracturing model experiment, in order to explore the coal reservoir reconstruction technology under deep geological conditions. Based on the above basic research, the volume acid fracturing technology characterized by high displacement, low …
Exploration Of Integrated Technology For Deep Coalbed Methane Drainage In Full Life Cycle: A Case Study Of Daning‒Jixian Block, Zeng Wenting, Ge Tengze, Wang Qian, Pang Bin, Liu Yinhua, Zhang Kang, Yu Lizhu
Exploration Of Integrated Technology For Deep Coalbed Methane Drainage In Full Life Cycle: A Case Study Of Daning‒Jixian Block, Zeng Wenting, Ge Tengze, Wang Qian, Pang Bin, Liu Yinhua, Zhang Kang, Yu Lizhu
Coal Geology & Exploration
The first deep coalbed methane (CBM) field with a depth of more than 2 000 meters in China has been proven in Daning‒Jixian Block on the eastern margin of Ordos Basin, where the deep coal bed has the characteristics of large buried depth, high pressure, high gas content, high gas saturation and low permeability. Besides, the features of early gas occurrence, high gas-liquid ratio and high salinity of produced liquid are shown in the production process. Problems such as corrosion, anti-eccentric wearing, gas locking and pump blocking were encountered in the application of suction pump based lifting system in the …
Production Characteristics Of Deep Coalbed Methane Gas Reservoirs In Daning-Jixian Block And Its Development Technology Countermeasures, Nie Zhihong, Shi Xiaosong, Sun Wei, Yan Xia, Huang Hongxing, Liu Ying, Feng Yanqing
Production Characteristics Of Deep Coalbed Methane Gas Reservoirs In Daning-Jixian Block And Its Development Technology Countermeasures, Nie Zhihong, Shi Xiaosong, Sun Wei, Yan Xia, Huang Hongxing, Liu Ying, Feng Yanqing
Coal Geology & Exploration
The Ordos Basin is rich in deep coalbed methane resources with a depth of more than 2 000 m, which is an important coalbed methane exploration and development area. A number of tests on deep coalbed methane have been carried out in Daning-Jixian Block, and preliminary results have been achieved, but the main technology of scale-efficient development needs to be studied. On the basis of the analysis of experimental data, production data and fracture monitoring data, and by the evaluation of the characteristics, production performance and fracturing effect of deep coalbed methane reservoirs in Daning-Jixian Block, the production characteristics of …
Progress Of Coalbed Methane Exploration And Development In China During The 13th Five-Year Plan Period And The Next Exploration Direction, Ye Jianping, Hou Songyi, Zhang Shouren
Progress Of Coalbed Methane Exploration And Development In China During The 13th Five-Year Plan Period And The Next Exploration Direction, Ye Jianping, Hou Songyi, Zhang Shouren
Coal Geology & Exploration
Based on survey data of coalbed methane exploration and development projects in China, the production status of coalbed methane fields and scientific & technological achievements, this paper analyzes the comprehensive control technical measures for stable and increasing production of coalbed methane fields, and the geological conditions and potential of deep coalbed methane exploration breakthrough. The coalbed methane horizontal well technology and the matching well pattern optimization and drainage technology are also summarized. The results show that the most effective technical measures for the comprehensive control of stable production of coalbed methane fields and low production wells in China are four …
Influencing Factors On Gas Production Effect Of Acid Fractured Cbm Wells In Deep Coal Seam Of Daning-Jixian Block, Li Shuguang, Wang Hongna, Xu Borui, Zhen Huaibin, Wang Chengwang, Yuan Pu
Influencing Factors On Gas Production Effect Of Acid Fractured Cbm Wells In Deep Coal Seam Of Daning-Jixian Block, Li Shuguang, Wang Hongna, Xu Borui, Zhen Huaibin, Wang Chengwang, Yuan Pu
Coal Geology & Exploration
The No.8 deep coal seam in Daning-Jixian Block is large, thick, widely distributed, and rich in coalbed methane(CBM) resources. After volume acid fracturing, a breakthrough has been achieved in the producing test. However, the productivity of the testing wells varies greatly, and the major controlling factors of productivity are not clear, severely restricting the CBM development. In this paper, the testing wells in the No.8 coal seam with a buried depth of more than 2 000 m of the Upper Carboniferous Benxi Formation in Daning-Jixian Block were taken as the research object, and 28 typical evaluation indicators were selected from …
Geological Unit Division And Development Countermeasures Of Deep Coalbed Methane In Southern Yanchuan Block, Chen Zhenlong
Geological Unit Division And Development Countermeasures Of Deep Coalbed Methane In Southern Yanchuan Block, Chen Zhenlong
Coal Geology & Exploration
Deep coalbed methane resources have great potential, accounting for 62.8% of the total resources. However, effective development faces many challenges such as strong heterogeneity, high geostress, difficult process matching and low production capacity. Taking the deep coalbed methane in Southern Yanchuan Block as an example, the key parameters are overlaid and analyzed, the development geological units of the gas field are finely divided according to the five controlling factors of “sedimentation coal-control, tectonic influenced accumulation, hydrodynamic gas-control, geostress seepage-control, physical property production-control”. The key geological attributes and development constraints of each development geological unit are clarified, and the differentiated development …