WEBJan 1, 2021 · Airleakage is one of the main reasons leading to poor coal seam gas (CSG) extraction performance, and needs to be mitigated urgently. ... and (Wang et al., 2021a,b) conducted an experimental study on the air leakage process of coal seam gas drainage by using an integrated apparatus in the laboratory. Although this has a certain reference .
WhatsApp: +86 18203695377WEBThe appliion of this concept transforms equilibrium permeability models to nonequilibrium ones. Equilibrium models represent only two end points (before gas extraction/injection and after the completion of gas extraction/injection) while our nonequilibrium one represents the complete evolution of coal permeability between two .
WhatsApp: +86 18203695377WEBSep 15, 2023 · Liquid CO 2 injection into coal seam for CH 4 displacement is one of the important means to strengthen gas extraction and carbon sequestration in recent years. After liquid CO 2 is injected into coal seam, physical and chemical interactions occur with coal through the process of "liquid phase seepagephase transformation supercharging .
WhatsApp: +86 18203695377WEBApr 1, 2013 · The effects of directional compaction, nonDarcy flow and anisotropic swelling on the extraction of natural gas in coal seam reservoirs are important but not well understood so far. This paper investigated these combined effects through a numerical model which fully couples the interactions of coal seam deformation, anisotropic gas .
WhatsApp: +86 18203695377WEBJan 13, 2023 · 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 18203695377WEBJun 7, 2022 · new technology of largediameter mechanical cavemaking to promote gas extraction. in a coal seam. This technology mainly uses the pressure of a water injection pump. to control the automatic ...
WhatsApp: +86 18203695377WEBJun 14, 2023 · The FLAC 3D numerical simulation software simulated the gas extraction process from the coal seam using directional boreholes. Optimal drilling parameters were determined by analyzing plasticity, stress, and enhanced permeability zone distribution patterns during gas extraction with different borehole radii. A .
WhatsApp: +86 18203695377WEBJan 1, 2023 · A Nonequilibrium model for coal multiphysics. In this section, a nonequilibrium coal multiphysics model is formulated, which includes three governing equations representing mechanical deformation of coal seams, gas flow in the fractures and matrixfracture mass transport, respectively. The new nonequilibrium porosity and permeability .
WhatsApp: +86 18203695377WEBNov 1, 2022 · The above methods of strengthening coal seam gas extraction introduces one or more gases into the coal seam. The influence of such methods on coal seam gas migration still needs further discussion. ... In summary, other key scientific issues involved in the process of coal mine gas extraction are to reveal the flow state of fluid in the cross ...
WhatsApp: +86 18203695377WEBMay 9, 2018 · Coal seam gas (CSG) is an increasingly important source of natural gas all over the world. Although the influence of conventional oil and gas extraction on surface subsidence has been widely ...
WhatsApp: +86 18203695377WEBApr 1, 2016 · The gas production from the conventional fields in the Surat Basin steadily increased from an average of 10 BCF/yr in the 1970s to peak at BCF in the 1994/95 fiscal year (Fig. 3).Production from Denison Trough (Bowen Basin) gas fields supplemented Surat production from 1988, supplying industrial users in Gladstone (via .
WhatsApp: +86 18203695377WEBJan 15, 2019 · One 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 18203695377WEBOct 1, 2020 · Typically, the gas reserves are loed in coal seams which are several hundred meters below ground. 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].
WhatsApp: +86 18203695377WEBFeb 26, 2022 · The highest gas pressure and the maximum gas content in the coal seam were MPa and m 3 /t, respectively. There was a high coal and gas outburst hazard in the coal seam and, therefore, it was necessary to improve the elaborate identifiion and realtime monitoring on the outbursthazardous zones in the coal seam.
WhatsApp: +86 18203695377WEBJun 21, 2023 · Coal Seam Gas. Coal Seam Gas (CSG) is a naturally occurring methane gas found in most coal seams and is similar to conventional natural gas. In Australia the commercial production of CSG commenced in 1996 in the Bowen Basin, Queensland. Since then production has increased rapidly, particularly during the first decade of the .
WhatsApp: +86 18203695377WEBJun 6, 2022 · The coal output of a single cave is approximately t/m, and the pressure relief effect is obvious. When the measurement range is 50 m, the average gas concentration for the mechanical cavitation drilling is 50%. The net amount of gas drainage is m 3 /min. The net volume of single cycle drainage is 60,480 m 3.
WhatsApp: +86 18203695377WEBMay 15, 2024 · As the initial coal seam temperature during the gas extraction process increases, the disparity between the coal seam temperature and the initial temperature becomes more pronounced, as illustrated in Figure 21. This is because as the initial coal seam temperature rises, the desorption amount of gas at the same extraction time also .
WhatsApp: +86 18203695377WEBJan 19, 2016 · Biochemical reactions associated with this process transform the organic matter into humic substances, which are the precursors of coal macerals. ... an isotherm should be obtained from each major coal seam. These isotherms can be used to determine the saturation state and estimate a recovery factor by comparing the expected gas .
WhatsApp: +86 18203695377WEBThe initial phase of CSG production usually involves the extraction of formation water from the coal seams in order to reduce the water pressure and release gas from the coal. At the surface, water in the gas is separated and piped elsewhere for use or further treatment. Gas from underground coal gasifiion (UCG) is sometimes confused with ...
WhatsApp: +86 18203695377WEBOct 27, 2023 · The gas extraction quantity is affected by gas pressure, permeability, and coal seam buried depth in the actual process of gas extraction, which is variable and complex. There is an interaction influence between each factor, which provides us with valuable guidance for analyzing the coupling change law of gas extraction quantity.
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