WEBFeb 1, 2024 · Abundant industrial experiences have shown that directional air drilling technology is effective for gas drainage when drilling broken and soft coal seams. In this paper, the Eulerian–Eulerian model was used to simulate the gas–solid twophase flow behavior of compressed air transporting coal dust in broken soft coal seams. The .
WhatsApp: +86 18203695377WEBNov 18, 2023 · In the geological history process of coal seam deposition and accumulation, the coal seam is reformed, such as sealing gas, forming tectonic coal mass, generating tectonic stress, et al. ... which make it difficulty to deplete coal seam gas, and greatly increases the risk of coal and gas outburst. On November 25, 2017, a dynamic .
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 18203695377WEB1 INTRODUCTION. Gas disaster is one of the important factors threatening the safety production of coal mines. 13 As the main energy source of China, ensuring efficient coal mining is an important strategy for China. 46 For coal and gas seam, drilling for gas extraction has the advantages of a short construction period, low construction cost, long .
WhatsApp: +86 18203695377WEBJun 1, 2024 · The coal seam water injection process involves a coal body gradually becoming saturated with water [36]. As shown in Fig. 4, after the fracture network in the area near the borehole has been gradually saturated with water, water seepage from this area is the main flow near the borehole. As the injected water advances, the gas in the .
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 21st .
WhatsApp: +86 18203695377WEBJul 11, 2022 · Secondly, the mechanism of N 2 injection to enhance coal seam gas drainage (N 2ECGD) was discussed: with the gradual decrease of gas pressure in the drainage process, coal seam gas enters a lowpressure state, the driving force of flow is insufficient, and the drainage enters the exhaustion period. The nitrogen injection .
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. These reactions can also generate significant amounts of biogenic methane, which often is referred to as swamp gas. ... In general, coal seam gas contents are less than the amount of gas a .
WhatsApp: +86 18203695377WEBFeb 11, 2022 · Gas is one of the main factors causing coal mine accidents in China. Understanding the mechanism of the influence of mine pressure on coal seam gas emission has important theoretical guiding significance for coal mine enterprises to be able to control gas. This paper chose the 72,909 working face in the Du'erping coal mine as .
WhatsApp: +86 18203695377WEBMar 15, 2020 · In the process of improving coal seam gas pressure relief and permeability by pulsating hydraulic fracturing, it is bound to have a certain influence on the microscopic pore characteristics of coal, change the pore characteristics of coal, thus affect the process of gas migration, and affect the microscopic dynamic characteristics such as .
WhatsApp: +86 18203695377WEBDec 15, 2021 · The output process of underground coal seam gas displacement by injecting nitrogen can be divided into two stages approximately. In stage I, driven by the pressure gradient, CH 4 in the original free state is the main product. While in stage II, the desorbed CH 4 from adsorbed state is the main product driven by the concentration .
WhatsApp: +86 18203695377WEBDec 21, 2017 · The process depressurizes the coal seam, permitting the gas in the openings of the coal to become free and move outward. A pipe wrapped with layers of metal or concrete, practically in order to prevent leaking into aquifers, is exploited to carry gas and fluid from coal seam to the surface (Batley and Kookana 2012 ; Fakhru'lRazi .
WhatsApp: +86 18203695377WEBDec 18, 2021 · In recent years, many studies have reported the mechanism of CH4 stimulation by gas injection. However, the studies have focused only on monitoring CH4 and CO2 in the tail gas. Thus, it is difficult to distinguish the adsorbed and free gas in the coal and rock and accurately calculate the CO2/CH4 replacement ratio in the .
WhatsApp: +86 18203695377WEBFeb 1, 2019 · 1. Introduction. Coal seam gas (CSG) is an unconventional resource which has been exploited in recent years as a substitute for coal and oil [1].Gas extraction involves decreasing the water pressure which holds the methane in place in the coal cleats [2, 3].Through this process, significant volumes of associated water are produced .
WhatsApp: +86 18203695377WEBApr 1, 2016 · In the process shown in this figure, the gas is filtered to remove solids, stripped of carbon dioxide and water using the standard amine and glycol units and then cooled by contacting the gas first with liquid propane, followed by ethylene and liquefied methane. ... A recent working paper from The University of Queensland's Centre for .
WhatsApp: +86 18203695377WEBIt deals directly with the physical behavior of the coal seam as a reservoir. Coal seams show considerable differences in behavior from normal porous gas reservoirs in both the mode of gas storage and permeability characteristics. Most of the storage of gas in coal is by sorption into the coal structure, while the coal permeability is cleat ...
WhatsApp: +86 18203695377WEBUnconventional contingent gas reserves for Australia, other than coal seam gas, are reported from an insitu coal gasifiion demonstration plant at Leigh Creek in South Australia. The total 2P reported reserves of syngas for the Leigh Creek Energy Project in the Telford Basin are 1,153 PJ ( Tcf) (Table 3).
WhatsApp: +86 18203695377WEBJul 1, 2017 · Considering the fracture evolution process in coal, Yang et al. developed a gassolid coupling model of coal seam containing damage, and then simulated the gas drainage process in a deep coal seam [21]. Xu et al. studied the numerical simulation of coal and gas outburst by using the relevant theory of fluidsolid coupling [22].
WhatsApp: +86 18203695377WEBFeb 1, 1987 · Summary. This is the first of two papers concerning the movement of gas in coal seams. It deals directly with the physical behavior of the coal seam as a reservoir. Coal seams show considerable differences in behavior from normal porous gas reservoirs in both the mode of gas storage and permeability characteristics. Most of the storage of .
WhatsApp: +86 18203695377WEBCoal is a combustible black or brownishblack sedimentary rock, formed as rock strata called coal is mostly carbon with variable amounts of other elements, chiefly hydrogen, sulfur, oxygen, and nitrogen. Coal is a type of fossil fuel, formed when dead plant matter decays into peat which is converted into coal by the heat and pressure of deep .
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