WEBDownload scientific diagram | Coal seam gas production process (created by the author using data from Rice and Nuccio 2000) from publiion: A study on the carbon dioxide injection into coal seam ...
WEBApr 1, 2023 · Zhangcun coal mine is loed at the northeast of Changzhi City in Shanxi Province, China. The 3# coal seam is characterized by thickness of ∼6 m, high gas content of m 3 /t, and low permeability of × 10 −17 m shown in Fig. 3 (a), gas extraction is adopted to deplete gas from coal seam, and the inseam boreholes with .
WEBDec 15, 2021 · 1. Introduction. According to the Global Energy Statistical Yearbook 2020, the total proven reserves of natural gas worldwide amount to trillion m total production is billion m 3, and the total consumption is 3, billion m 3 with a share of % in primary energy [1].Coal seam gas (CSG) accounts for 6%–9% of .
WEBSep 1, 2015 · Despite long extraction times, the amount of extracted gas is very low due to low gas permeability in Chinese coal seams. Therefore, the coal seam requires significant structural changes to improve the efficiency of the gasextraction process and reduce the gasextraction time (Zhou et al., 2012).
WEBThe 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 .
WEBMay 1, 2016 · Based on the multiphysics field theory, the hydraulicmechanical coupling model of gas extraction in the unloading coal seam was established, and the gas extraction process by drilling borehole in ...
WEBAug 1, 2018 · The initial temperature of coal seam has a significant influence on gas extraction, the higher the initial temperature of the coal seam, the smaller the gas production rate is. This is because the gas drainage process is the joint action of coal seam damage, gas pressure, adsorption and desorption of gas, and temperature.
WEBMethane is the major component of gas in coal, comprising 80%–95% of the total gas content. The balance is made up of ethane, propane, butane, carbon dioxide, hydrogen, oxygen, and argon. All coal seams begin to oxidize when exposed to ventilation air in a mine and produce some carbon monoxide and hydrogen sulfide.
WEBOct 26, 2023 · In order to develop precise hole placement technology for gas extraction, this paper combines industrial testing, the evolution law of coal rock damage permeability, and the coal doublepore doublepermeability model; establishes a coupling model of the coal damage deformation field and matrixfracture double diffusion seepage field; and .
WEBFeb 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.
WEBDec 9, 2023 · Efficient gas extraction is important for reducing coal mine gas accidents and protecting the environment. A prerequisite for achieving efficient gas drainage is to clarify the evolution rules of mining fractures and the development characteristics of gas migration channels. In this study, aiming at the rock structure of coal seam composite .
WEBMay 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 recognized and studied, few studies are carried out on the surface subsidence in coal seam gas fields and its impact on surface infrastructure and .
WEBJun 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 ...
WEBMay 21, 2015 · By integrating coal production with gas extraction, coal seam gas becomes a useful resource. Advantage is taken of the effect of strata movement on gas pressurerelief and flow during the coal mining process to establish a single production system for simultaneous coal and gas extraction.
WEBApr 1, 2022 · Section snippets Basic assumptions. Coal seams generally contain both coal matrix and fractures, which are typical of dualporosity media [52]. To simplify the methane gas flow process in coal as much as possible, we refer to previous literature [12], [51] when building the dualporosity model of coal bodies and make the following .
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 .
WEBSep 19, 2023 · The gas migration process in the coal seam can be divided into gas desorption and diffusion in the matrix to the fractures and then into the borehole through seepage. ... Zhang J, Liu Y, Ren P, Han H, Zhang S (2021) A fully multifield coupling model of gas extraction and air leakage for inseam borehole. Energy Rep 7:1293–1305
WEBSep 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 .
WEBThe 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 ...
WEBDec 29, 2023 · In order to increase the permeability of low permeability and high gas coal seam and improve the efficiency and utilization of gas extraction, the permeability enhancement technology of deep hole presplitting blasting is proposed, and the mechanism of blasting induced cracking of deep hole presplitting blasting is analyzed. .
WEBJun 1, 2021 · 1. Introduction. As the companion of coal seam, coal mine gas (CMG) is a major hazard source to coal mining practice. During the mining process, gas disasters such as gas explosion, gas combustion, and coal and gas outburst may occur, resulting in serious casualties and property losses. 1, 2 Especially when it enters deep mining, .
WEBSep 27, 2021 · DSI is a function of the gas pressure, and its magnitudes are regulated by the Langmuir constants of both the solid grains and the coal bulk. Furthermore, a DSIbased coal permeability model is incorporated into the coupled multiphysics model for coal seam gas production. The model results of both laboratoryscale and fieldscale show .
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