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Full-Text Articles in Mining Engineering
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 …
Fracture Propagation Mechanism In Directional Perforation And Hydraulic Fracturing Of Coal Seam Horizontal Wells, Pang Tao, Jiang Zaibing, Hui Jiangtao, Jia Bingyi
Fracture Propagation Mechanism In Directional Perforation And Hydraulic Fracturing Of Coal Seam Horizontal Wells, Pang Tao, Jiang Zaibing, Hui Jiangtao, Jia Bingyi
Coal Geology & Exploration
Horizontal well perforation and fracturing in complex coal-bearing strata are key to increasing coal seam permeability and enhancing gas extraction efficiency, with the formation structure and perforation location determining fracture propagation. Considering the characteristics of formation structure and perforation locations, a fracturing geological model is established. Based on the finite element method, a numerical model is constructed to study the effects of perforation location, formation conditions, and the difference between vertical stress and horizontal stress on fracture perforation. Engineering verification is conducted, and construction suggestions are proposed. Key findings are as follows: There are three scenarios for the perforation locations: …
Moderately Deep Coalbed Methane Reservoirs In The Southern Qinshui Basin: Characteristics And Technical Strategies For Exploitation, Zhang Cong, Li Mengxi, Hu Qiujia, Jia Huimin, Li Kexin, Wang Qi, Yang Ruiqiang
Moderately Deep Coalbed Methane Reservoirs In The Southern Qinshui Basin: Characteristics And Technical Strategies For Exploitation, Zhang Cong, Li Mengxi, Hu Qiujia, Jia Huimin, Li Kexin, Wang Qi, Yang Ruiqiang
Coal Geology & Exploration
This study investigated the northern Zhengzhuang-western Qinnan block for the purpose of achieving effective exploitation of moderately deep coalbed methane (CBM) reservoirs in the southern Qinshui Basin. Based on results from the analyses and tests of parametric wells, including core analysis and tests, injection/falloff tests, and in situ stress cyclic tests, as well as a large amount of dynamic and static data, this study expounded on the characteristics of moderately deep CBM reservoirs in the study area by comparison with shallow counterparts. Then, it explored the technical improvements in fracturing through vertical wells and staged fracturing through horizontal wells for …
R&D And Experimental Research Of Pressure-Preserved Triggering Device For Horizontal Pressure-Preserved Coring In Coal Mines, Huang Wei, Chen Ling, Li Jianan, Fan Dong, Yang Mingqing, Liu Guikang, Xu Qing, Ma Changliang
R&D And Experimental Research Of Pressure-Preserved Triggering Device For Horizontal Pressure-Preserved Coring In Coal Mines, Huang Wei, Chen Ling, Li Jianan, Fan Dong, Yang Mingqing, Liu Guikang, Xu Qing, Ma Changliang
Coal Geology & Exploration
Gas content is an important evaluation index of safe coal mining, as well as the exploitation and utilization of coalbed methane resources. Pressure-preserved coring is an effective way to improve the measurement accuracy of gas content in coal seams. Aiming at the special operating conditions of horizontal pressure-preserved coring in coal mines and based on the principle and technology of pressure- and gas-preserved coring in coal mines, this study developed a pressure-preserved triggering device and systematically designed the key components of the device, such as the sealing and pressure-preserved unit, the hydraulic drive module, and the salvager-unstuck mechanism between the …
Practice And Cognition Of Efficient Cbm Development Under Complex Geological Conditions: A Case Study Of Zhengzhuang Block, Qinshui Basin, Zhu Qingzhong, Li Zhijun, Li Zongyuan, Wang Sanshuai, Sun Ruixue, Wang Yuting, Xiao Yuhang, Wang Jingyue, Guan Xiaoqu
Practice And Cognition Of Efficient Cbm Development Under Complex Geological Conditions: A Case Study Of Zhengzhuang Block, Qinshui Basin, Zhu Qingzhong, Li Zhijun, Li Zongyuan, Wang Sanshuai, Sun Ruixue, Wang Yuting, Xiao Yuhang, Wang Jingyue, Guan Xiaoqu
Coal Geology & Exploration
The geological conditions of various CBM sites in China are complicated and features similarly. With the recent development of exploring CBM towards the medium-deep, ultra-low permeability and structurally complex areas, it is of great significance to develop a set of efficient exploring techniques in complex areas to revitalize a large number of domestic CBM resources. Taking an example of the successful development of Zhengzhuang Block with early low yield and relatively complex geology, it had faced a series of problems, including complex geological conditions with internal fracture, strong heterogeneity, low permeability, lack of corresponding developing technologies for the early stage …
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 …
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 …
Detection Performance Of The Azimuthal Electromagnetic Wave Logging Instrument At Coal-Rock Interface In Horizontal Wells, Zhang Yi, Kang Zhengming, Feng Hong, Han Xue, Li Fei, Li Xin
Detection Performance Of The Azimuthal Electromagnetic Wave Logging Instrument At Coal-Rock Interface In Horizontal Wells, Zhang Yi, Kang Zhengming, Feng Hong, Han Xue, Li Fei, Li Xin
Coal Geology & Exploration
The advance and accurate identification of coal-rock interfaces is one of the key technologies to realize intelligent mining, improve mining efficiency and reduce cost. Azimuthal electromagnetic wave logging has achieved good results in lithologic interface identification of petroleum logging, but the identification of coal-rock interface is seldom studied. For the purpose of studying the applicability and detection performance of azimuthal electromagnetic wave in the coalfield logging environment, the one-dimensional generalized reflection coefficient method is used to calculate the magnetic field component, and the fast Hankel transform is used to accelerate the integral calculation speed. What is more, the effects of …
Geosteering Technology And Cbm Horizontal Well Drilling Without Pilot Hole, Liu Mingjun, Li Bing, Huang Wei
Geosteering Technology And Cbm Horizontal Well Drilling Without Pilot Hole, Liu Mingjun, Li Bing, Huang Wei
Coal Geology & Exploration
Aiming at the difficulties of hole-forming of the horizontal interval in a soft coal seam, low drilling ratio of coal seam and need of pilot hole during deflecting drilling, the key technologies such as drilling parameter optimization, anti-collapse drilling were put forward in the paper. Geosteering technology with multi-markers was used to realize timely layer identification, to search suitable targeting angle, to be adaptive to the stratum dip so as to realize one time direct landing at the target. Geosteering and geometric steering were combined to control finely the wellbore trajectory of the horizontal interval, to make the wellbore trajectory …
Combined Cbm Production Behavior And Development Strategy Of Multiple Coal Seams In Zhijin Block, Guo Tao, Gao Xiaokang, Meng Guixi, Xiao Cui
Combined Cbm Production Behavior And Development Strategy Of Multiple Coal Seams In Zhijin Block, Guo Tao, Gao Xiaokang, Meng Guixi, Xiao Cui
Coal Geology & Exploration
Aiming at the problems that the CBM layers are numerous and thin, it is difficult to develop it effectively in south China, on the basis of the actual production data of CBM wells in Zhijin block, the production characteristics and the influencing factors of gas production of the directional wells for co-extraction of different seams and the horizontal wells for thin seams were analyzed, and corresponding suggestions for CBM development were put forward. The analysis indicated that the gas production of co-extraction of different seams was quite different, was influenced by the liquid-supplying capacity of formation, the height of desorbing …