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Full-Text Articles in Engineering
Evaluation Of Coalbed Methane Drainage Effect For Multi-Target Seams In Jincheng Region, Yang Jianchao, Li Guihong, Liu Yuhui, Li Guofu, Wang Chaoshuai, Sun Tianyu
Evaluation Of Coalbed Methane Drainage Effect For Multi-Target Seams In Jincheng Region, Yang Jianchao, Li Guihong, Liu Yuhui, Li Guofu, Wang Chaoshuai, Sun Tianyu
Coal Geology & Exploration
The study of the multi-target seams drainage effect on coalbed methane wells has great value, including coal safe mining, underground gas control, determination of development technical indicators, single well production, rational division of development layer, efficient development of coalbed methane, and development of medium and long-term coalbed methane development planning. Taking Chengzhuang mine of Jincheng as an example, the sampling data of the extraction effect in the middle and late stages of development are compared with the original gas content of the adjacent wells to evaluate the extraction effect, and the main control factors affecting the drainage effect are analyzed …
Analysis On The Type Of Reservoir Pressure Drop And Drainage Control Of Coalbed Methane Well In The Southern Block Of Shizhuang, Yi Yongxiang, Tang Shuheng, Zhang Songhang, Yan Xinlu, Wang Kaifeng, Dang Feng
Analysis On The Type Of Reservoir Pressure Drop And Drainage Control Of Coalbed Methane Well In The Southern Block Of Shizhuang, Yi Yongxiang, Tang Shuheng, Zhang Songhang, Yan Xinlu, Wang Kaifeng, Dang Feng
Coal Geology & Exploration
In order to fully understand the reservoir pressure variation characteristics of coalbed methane wells in the southern block of Shizhuang and based on the analysis of reservoir geological parameters and the analysis of actual production data, the reservoir pressures of different types of production wells are analyzed. The specific analysis of the drainage control and reservoir sensitivity effects is also carried out based on the abnormal wells. The results showed that the reservoir lamination of coalbed methane wells in the southern block of Shizhuang can be divided into three types, namely type of rapid pressure drop, type of medium-term stability …
Molecular Simulation Of The Influence Of Foam Fracturing Fluid Additives On Coalbed Methane Diffusion, Yang Zhaozhong, Han Jinxuan, Zhang Jian, He Rui, Lu Yanjun, Li Xiaogang
Molecular Simulation Of The Influence Of Foam Fracturing Fluid Additives On Coalbed Methane Diffusion, Yang Zhaozhong, Han Jinxuan, Zhang Jian, He Rui, Lu Yanjun, Li Xiaogang
Coal Geology & Exploration
Materials Studio(MS) software was used to establish a slit pore molecular model which considers the in-teractions among water-bearing coal, foam agent and foam stabilizer. Based on molecular diffusion theory, the diffusion ability of methane molecule respectively affected by four common foam agents and four foam stabilizers was calculated. Compared to original water-bearing coal, self-diffusion coefficient of coalbed methane(CBM) is reduced by 71.3%, 74.7%, 56.3%, 54.0% after adding foaming agents including sodium dodecyl sulfonate(SDS), sodium lauryl sulfate(SLS), sodium dodecyl benzene sulfonate(SDBS) and lycine respectively. Based on adding SDBS into water-bearing coal, the self-diffusion coefficient of CBM is further reduced by 63.2%, …
Estimation Method And Application Of Free Gas Content In Coal, Jiang Wenping, Zhang Qun, Zhang Peihe, Dong Mintao, Tian Xinjuan, Ru Ting
Estimation Method And Application Of Free Gas Content In Coal, Jiang Wenping, Zhang Qun, Zhang Peihe, Dong Mintao, Tian Xinjuan, Ru Ting
Coal Geology & Exploration
In order to study the distribution characteristics of free gas content in coal reservoirs, based on the understanding that free gas mainly exists in coal pores, the estimation method of free gas content is optimized. Based on the test data of coalbed methane arameters of 42 groups of coals with different ranks from lignite to anthracite in typical coal-bearing areas of China, the free gas content of different coal samples were calculated by using the optimized method of free gas content estimation, and compared with the results of desorption gas content. The results show that the ratio of free gas …
Technology And Application Of Indirect Fracturing In Cbm Vertical Well Of Broken And Soft Coal Seam With Low Permeability, Zhou Jiajia
Coal Geology & Exploration
In order to solve the problems of pulverized coal output and fracturing fracture not easy to extend during fracturing operation in the broken and soft coal seam with low permeability, the adaptability and fracturing fracture distribution of CBM during indirect fracturing are studied by means of in-situ stress and numerical simulation, and the engineering practice of indirect fracturing has been tested in Hongshandian mining area of Hunan Province. The results show that indirect fracturing can effectively improve the fracturing effect of the broken and soft coal seam with low permeability, and increase the fracture length. When the roof and floor …
Corrosion Behavior Analysis Of Sucker Rod For Coalbed Methane Wells In The Eastern Block Of Ordos Basin, Pang Bin, Wang Hanxiang, Lan Wenjian
Corrosion Behavior Analysis Of Sucker Rod For Coalbed Methane Wells In The Eastern Block Of Ordos Basin, Pang Bin, Wang Hanxiang, Lan Wenjian
Coal Geology & Exploration
In order to make clear the corrosion rule of sucker rod for coalbed methane wells in the eastern block of Ordos basin, the paper summarizes the corrosion types and corrosion intensities of the sucker rod, based on the test of produced gas, produced water, corrosion products and weight loss of sucker rod. The paper analyzes the effect of different drainage stages, coal seam and mineralization degree of water on the corrosion. The results of the research indicate that corrosion is mainly caused by CO2 and H2S originated from No.5 coal seam and No.11 coal seam. The corrosion …
Geological Characteristics And High Efficiency Development Technology Of Coalbed Methane In Duijiangnan Coal Mine, Guizhou Province, Gong Zewen
Coal Geology & Exploration
The development progress of coalbed methane in Duijiangnan mine field is slow. The main problems are low drilling efficiency, serious cementing leakage, long fracturing transformation period and low single well production in the block. Objectively evaluating the geological characteristics and development technology of coalbed methane is very im-portant for coalbed methane in the future. The coalbed thickness, coal body structure, reservoir pressure, gas content and permeability are systematically studied, combining with the past drilling, fracturing and drainage practices. It is proposed that directional wells are the main method of coalbed methane development in the coalfield. The coal seam M18 which …
Study On The Biodegradation Of Guanidine Gum By Methanogens In Coal Seam, Li Yunsong, Guo Hongyu, Fu Chaoyong, Zhao Guojun, Xia Daping
Study On The Biodegradation Of Guanidine Gum By Methanogens In Coal Seam, Li Yunsong, Guo Hongyu, Fu Chaoyong, Zhao Guojun, Xia Daping
Coal Geology & Exploration
The problem of low temperature breaking of guanidine gum fracturing fluid is related to the effect of coal seam penetration. In order to explore the effect of methanogenson the biodegradation of guanidine gum, Inner Mongolia some coal mine lignite were collected to prepare samples of coal samples, and the enriched fresh mine water was used as the bacteria source. The biological methane metabolism experiments of guanidine gum + coal were used to characterize the biodegradability of methanogens to guanidine gum, with the total gas production, CH4 concentration, guanidine gum molecular functional groups and C and H elements content changes. …
Analysis Of Diffusion Properties Of Methane In Low Rank Coal, Meng Zhaoping, Zhang Guiyuan, Li Guoqing, Liu Jinrong
Analysis Of Diffusion Properties Of Methane In Low Rank Coal, Meng Zhaoping, Zhang Guiyuan, Li Guoqing, Liu Jinrong
Coal Geology & Exploration
Diffusion properties of methane in coal is an important reservoir parameter affecting CBM production. Using the lignite samples from the Xiaolongtan Formation of the Miocene Neogene in southeastern Yunnan Province, the isothermal adsorption experiments of methane in low rank coal were carried out. Based on the relationship between adsorption amount and time obtained from isothermal adsorption experiment, the diffusion coefficient of methane in coal was calculated by using an unipore model of unsteady gas diffusion. The diffusion law of methane in coal and its control mechanism were revealed. The results show that gas diffusion law in coal obeys Langmuir equation; …
Numerical Simulation Of Borehole Stability In Underbalanced Drilling Coal Seam, Yumei Li, Su Zhong, Zhang Tao, Delong Zhang, Liwei Yu, Si Na
Numerical Simulation Of Borehole Stability In Underbalanced Drilling Coal Seam, Yumei Li, Su Zhong, Zhang Tao, Delong Zhang, Liwei Yu, Si Na
Journal of System Simulation
Abstract: According to the formation parameters of No.3 coal seam in the Qinshui Basin, Shanxi Province, considering the interaction between seepage and deformation in the borehole wall of coal seam, using the finite element method for establishing the stable elastoplastic numerical model of the borehole in coal seam,the variation of pore pressure near the wellbore wall with the seepage time and the effect of time delay on wellbore stability under underbalanced drilling condition were studied. The variation law of maximum displacement and maximum plastic deformation around borehole wall with bottom pressure were analyzed. The simulation results show that there …