1 Introduction. Recovery of coalbed methane (CBM) from coal seams can not only benefit mining safety, reduce greenhouse gas emissions, and also increase clean energy supply (Karacan et al., 2011; Moore, 2012).In the Junggar Basin, the CBM resources have been estimated at trillion cubic meters, which is the third largest CBM basin in China after the Qinshui Basin and Ordos Basin (Fu et al ...
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In this paper, using the continuumdiscontinuum element method (CDEM), the fragmentation and outburst process of coal specimen are simulated, and the main factors affecting coal breaking and outburst are explored. The results show that after the coal seam is uncovered, coal generates obvious failure and outburst trend. Near coalfree surface, the fracture coal blocks generate significant ...
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Coal seam gas extraction is not only a source of clean and natural energy but also a means to address the pressing issue of gas control . Undoubtedly, methane, a crucial element of coal mine gas, is a potent greenhouse gas [ 8 ].
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For the gas extraction process, the larger the plastic zone created by the coal body around the borehole, the wider the range of fissures created and the greater the permeability, the more conducive to gas extraction and the increase in extraction rate. ... "Numerical Simulation of Gas Extraction in Coal Seam Strengthened by Static Blasting ...
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In the process of coal mine gas extraction, it is necessary to ensure the effective gas extraction in all directions in the mine so as to prevent and control the gas disaster. ... Xiaocun C, Hui T (2018) Technical scheme and application of pressurerelief gas extraction in multicoal seam mining region. Int J Min Sci Technol 28(3):483489 ...
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In order to reveal the process and mechanism of gas flow in a lowpermeability coal seam, a new multiplerelaxationtime lattice Boltzmann method (MRTLBM) model of gas migration in coal micro/nanopores based on Langmuir monolayer adsorption theory, the slip boundary scheme and Bosanquet effective viscosity was established. The software MATLAB was used to carry out the simulation study of ...
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To produce gas from coal seams, water must be extracted first, lowering the pressure so the gas can flow out of the coal. The volume of groundwater extracted can vary significantly between individual wells, coal seams and coal basins, depending on geological conditions.
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CBM is also known as virgin coal seam methane or coal seam gas, and is widely considered an "unconventional" source of natural gas. In the United States, CBM is a valuable resource that accounts for about 5% of total natural gas production annually. More information on CBM production in the United States.
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To produce coal seam gas (CSG), wells are drilled into underground coal seams, bringing water (CSG water) from the seams to the surface. This process reduces pressure in the seams which allows CSG to be released. The quality of CSG water quality varies greatly, however it is generally rich in salts and other minerals.
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The widely spread CarboniferousPermian coal seam group in southern China has great potential for coalbed methane resources, but the extensively developed tectonically deformed coal seriously restricts its development. Taking the Dahebian block in western Guizhou as the study area, the geological model of coalbed methane reservoirs in the tectonically deformed coal seam group was established ...
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1. Introduction. The efficient extraction of gas ensures the safe production of coal mines. It also contributes to clean energy and reduces methane emissions in the process of coal mining. 1,2 In fact, it can be used as a carbon emission reduction approach for coal enterprises and a positive response to the goal of "carbon peaking and carbon neutrality".
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Gas transport mechanism during coalbed gas extraction process . ... the coal seam with low gas content and without outburst risk is chosen as the first coal seam to be mined. As shown in Figure 13, the rock mass moved to the gob after the first coal seam was mined. Then, it formed three zones above the mining coal seam: caving zone, fractures ...
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The method of predicting whether it is an outburst danger zone stipulated in the "Coal and Gas Outburst Prevention Rules" is based on the coal seam gas pressure of MPa and the content of 8 m 3 / t as the critical value. Reducing the gas pressure of coal seam to MPa during the extraction process is an important discriminant index.
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This hole collapse leads to a failure to seal the hole and effectively extract the C 4, C 3, and C 2 coal seam gas from the upper part of the C 7+8 coal seam, making it difficult to ensure that the C 2 coal seam gas extraction process meets the required standard. Based on this, the crosslayer hole expansion and permeability enhancement ...
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A large amount of CH 4 gas is stored in coal matrixes through the adsorption process at greater pore fluid pressure. As a result, when the pore pressure reduces to cause the desorption process to desorb this stored CH 4 gas, the CH 4 gas can be continuously produced. To reduce the pore fluid pressure, first naturally remaining pore water is pumped out through a drilled well and then along with ...
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When rockbursts and coal and gas outbursts simultaneously occur in a coal mine, changes in gas adsorption (concentration of ambient methane) and displacement of coal and rock must occur. The coassociated minerals in coal reservoirs can affect the mechanical properties and methane adsorption capacity, which are commonly disregarded. It is important to construct compound molecular structure ...
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Gas preextraction technology in a coal reservoir can not only reduce greenhouse gas (GHG) emissions but also effectively recover coalbed methane (CBM). In this work, we use a geomechanicalcoupled gas flow (GCF) model to simulate and analyze the preextraction effect of a miningdisturbed coal seam. First, the simulation results of the GCF model are compared with field test data to verify the ...
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In order to improve the efficiency of gas extraction in coal mines, a datadriven finemanagement and control method for gas extraction is proposed. Firstly, the accurate prediction of coal seam thickness and gas content was used to evaluate the gas reserves. Based on the time relationship between mining activities and gas extraction, the calculation model of borehole distance in different ...
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Coal Seam Gas Extraction by Integrated Drillings and Punchings from the Floor Roadway considering HydraulicMechanical Coupling Effect Geofluids / 2022 / Article Special Issue NonAqueous Fracturing for Unconventional Oil, Gas, and Geothermal Reservoirs View this Special Issue Research Article | Open Access
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Coal seam gas overall process The development of unconventional gas resources such as shale gas and coal seam gas has boomed over the past few years [1]. Coal seam gas (CSG) also known as coal bed methane (CBM) is comprised of natural gas that is extracted from low to high rank coal beds [2], [3].
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Within the USA, both coal seam gas (8% of total natural gas produced) and shale gas industries (30% of total) are in substantial growth phases. Although A. Gore, D and Davies, P (2013) Department of Environment and Geography, Macquarie University, Background paper on produced water and solids in relation to coal seam gas production: Report
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This study used computer simulation to select appropriate process designs to make coal seam gas (CSG) associated water comply with beneficial reuse regulations. ... The extraction process involves depressurization of the seams [3], which results in the collection of substantial amounts of CSG associated water which is saline in character [4 ...
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Environmental impact of coal mining and coal seam gas production on surface water quality in the Sydney basin, Australia. Environ Monit Assess. 2017 Aug;189(8):408. doi: /s . It also contributes to greenhouse gas emissions, both through the direct release of methane during extraction and the burning of the gas for energy.
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A material supplier from Belgium would like to produce limestone powder for his custome...
India is rich in various mineral resources and it is an important mineral processing market
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