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.
WhatsApp: +86 18203695377Gas extraction is the main method to reduce gas content and eliminate gas accidents, and due to the influence of mining stress in the coal seam mining process, there are elastic damage zones and plastic damage zones of coal seams [3, 7]. Therefore, in order to improve the efficiency of gas extraction, it is necessary to study the elastic ...
WhatsApp: +86 18203695377Coal seam gas extraction: modelling groundwater impacts . uncertainty analysis, presentation and documentation of outputs). The modelling process is influenced by, objectives, conditions, data and scale of impact. Groundwater modelling tools . Groundwater modelling tools can simulate the potential groundwater impacts from coal seam gas production.
WhatsApp: +86 18203695377CSG is extracted through wells drilled into coal seams. The initial phase of CSG production usually involves the extraction of water from the coal seams in order to reduce the pressure and release gas from the coal. If the pressure within the seam is high, the gas may flow to the surface unaided.
WhatsApp: +86 18203695377From this, the primary equipment and key production technologies were determined for the proposed softrock protective seam mining. Finally, in combination with the optimal arrangement of the working face, the pressurerelief gas extraction technology accomplished the pressurerelief mining of the protected coal seam. 2.
WhatsApp: +86 18203695377As the coal mining depth increases, the coal seam gas pressure and gas content increase, mining conditions become more complicated, and the coal seam permeability decreases. ... hydraulic method is to use the hydraulic shocking impact to form a network of fractures. 20 A schematic diagram of the CH 4 extraction process by fracturing is shown in ...
WhatsApp: +86 18203695377During the stable gas production stage, the highest AMCCF value was %, and the PZCF was less than mm. It hardly produced coal fines during the gas production decay stage, and the PZCF was generally less than 1 μm. (4) The control of faults on coal fines production weakened as the distance from a fault increased.
WhatsApp: +86 18203695377In order to solve the problem that the gas in the upper corner is easy to exceed the limit in the mining process of the deep outburst coal seam. Based on the theory of "Oring" and the distribution of stratigraphy in the field, the development law of mining fissures in the overlying rock layer during the workface retrieval was studied by combining theoretical calculation and ...
WhatsApp: +86 18203695377Low permeability of a reservoir directly makes gas extraction in deep coal seams more difficult. However, under the strong disturbance of mining, substantial gas emissions from coal seam may cause gas overrun in the working face and even bring gas explosion accidents.
WhatsApp: +86 18203695377When 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 ...
WhatsApp: +86 18203695377The insitu gasification process (ISG) produces methane, hydrogen and other valuable components. The synthetic gas (syngas) can be used to produce electricity directly or further refined into a variety of products including synthetic methane and ammonia. The ISG demonstration project was built to inform the design for a potential commercial ...
WhatsApp: +86 18203695377Coal 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].
WhatsApp: +86 18203695377Within 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
WhatsApp: +86 18203695377Coalbed methane (CBM), is also known as coalbed gas and coal seam gas/methane (CSG/CSM), which are terms referring to the unconventional natural gas resource stored in coal beds and are expected to be an important energy resource of global significance in the future (Rightmire 1984; Rice 1993; Flores 1998, 2013; Palmer 2010; Yang and Liu 2021). ...
WhatsApp: +86 18203695377Fig. 1 Schematic of gas within a coal seam (Williams et al. 2013 ). Coal seam gas is trapped in pores and micropores, in the form of free or adsorbed gas. By reducing the hydraulic pressure, which is exerted via water and overlying aquifers to the seam, the gas is extracted through drilled wells.
WhatsApp: +86 18203695377How gas extraction can unearth cleaner energy sources Monash Lens While fracking is highly controversial, the lessons from pursuing coal seam gas are already helping us understand and improve on a form of renewable energy also found deep underground geothermal energy. Read more at Monash Lens.
WhatsApp: +86 18203695377Integrated coal production and gas extraction must be considered as a system which involves the exploration and measurement of stress field redistribution, deformation and failure of coal and rock, gas pressure and permeability, and gas desorption and migration during the process of coal mining. Fundamental theory
WhatsApp: +86 18203695377One potential source of energy is extraction of unconventional gases, such as basincentered gas, tight gas, coal seam gas (CSG) and shale gas [1]. The extraction of natural gas from low permeability unconventional reservoirs requires methods to improve access to the reservoir. 'Hydraulic fracturing' is one such technique which has made gas ...
WhatsApp: +86 18203695377CBM is also known as 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.
WhatsApp: +86 18203695377Coal is a black or brownishblack sedimentary rock that can be burned for fuel and used to generate is composed mostly of carbon and hydrocarbons, which contain energy that can be released through combustion (burning). Coal is the largest source of energy for generating electricity in the world, and the most abundant fossil fuel in the United States.
WhatsApp: +86 18203695377Based on the basic geological data and production data of coalbed methane wells in the Shouyang Block, the characteristics and influencing factors of coalbed methane well production were analyzed, and the primary controlling factors were identified by the grey correlation method. The results show that the average daily gas production of the coalbed methane wells in the study area for the ...
WhatsApp: +86 18203695377Section snippets Theory. Borehole gas predrainage is the most common way in the extraction process of gas resources [26]. However, the stress concentration phenomenon around the borehole readily leads to localized damage to the borehole wall and the formation of many crushed coal masses and broken coal, which are the main channels for gas flow around the borehole.
WhatsApp: +86 182036953771. 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".
WhatsApp: +86 18203695377Coal 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 ].
WhatsApp: +86 18203695377Coal mine gas accidents have been one of the most serious disasters in the process of coal mining in China that seriously affect the safety of mine production and the life safety of miners. (1−5) At present, the fundamental method to prevent coal seam gas disasters is to increase the permeability of coal seam.
WhatsApp: +86 18203695377sitional flow for the premining coal seam gas extraction. Yang et al. [13] combined the evolution of stress, damage, and gas permeability with the deformation of coal and rock. Gao et al. [14] and Liu et al. [15] considered the thermal effect for extraction of coal seam gas with slotted boreholes.
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