Exploration of alternative energy resources has become essential to fulfill an everincreasing energy demand. 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 ...
Then the gas flow rate changes gradually, which can be regarded as an inefficient mass transfer stage. Therefore, when there is a lateral heterogeneity in permeability during CBM well development (Fig. 6), the gas supply unit of coal is uneven, which is a process of the gas supply unit moving back to the far end of the well. The physical ...
The measurement of gas content in coal seam by means of indirect method involves heavy workload, long period, high cost and complicated operation and a proneness of negative values in the process of measuring gas absorption constant. To address these problems, the gas basic parameters and coal quality indexes of 90 coal samples from 90 coal mines in 13 provinces of China are determined ...
To study the differences between various gas injection sources in the process of coal seam methane replacement, experimental research was conducted to study the influences of different gas injection sources and gas injection ratios on coal seam methane replacement by considering the strong adsorption gas CO 2 and the weak adsorption gas N experimental results show that the temperature ...
Coalbed gas content is the most important parameter for forecasting and preventing the occurrence of coal and gas outburst. However, existing methods have difficulty obtaining the coalbed gas content accurately. In this study, a numerical calculation model for the rapid estimation of coal seam gas content was established based on the characteristic values of gas desorption at specific exposure ...
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 identification and realtime monitoring on the outbursthazardous zones in the coal seam.
Natural cavitation begins by drilling a targeted coal seam with air, gas, or mist. The bit is then lifted above the seam and the well is shut in. ... Jetting cavitation uses hydraulic pressure to direct a jet of gas and water directly toward the coal face. This process may be performed to facilitate a cavity when other cavitation methods have ...
article{osti_, title = {Reservoir engineering in coal seams: Part 1 The physical process of gas storage and movement in coal seams}, author = {Gray, I}, abstractNote = {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 ...
The results show that the evolution process of gas pressure in coal seam boreholes can be divided into two stages. In the first stage, the gas pressure increases rapidly, and the pressure change rate decreases continuously. In the second stage, the gas pressure is slow and stable, and the pressure change rate tends to 0.
List of Pros of Coal Seam Gas. 1. It is Effective. There is no doubt that coal seam gas actually works. Unlike solar power or wind turbines, coal seam gas is very costeffective and tremendously efficient. This means that rather than having to rely on a method that is very expensive or not guaranteed to work, we can simply use coal seam gas and ...
Coalbed 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). ...
The new framework for coal and coal seam gas (CSG) overlapping tenures (the framework) commenced on 27 September 2016. The framework regulates both the resource authority and safety ... dispute resolution process is available for certain matters. Parties can refer the following matters under the new framework to arbitration:
The Conversation.. A study from 2017 found that air pollution from CSG mining could pose a significant threat to public health, particularly in terms of respiratory diseases A Ali, V Strezov, P Davies, I Wright (2017, Jul 21). Environmental impact of coal mining and coal seam gas production on surface water quality in the Sydney basin, Australia.
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].
Clisby Engineering works closely with many upstream gas operators, principally designing and supplying process equipment. Clisby has focused particularly within the significant Australian Coal ...
In the process of coal seam drilling and gas drainage, the gas pressure around the coal seam and the stress of the coal and rock mass change, resulting in a change in coal porosity. A mechanically overexcavated cavity diameter of 1200 mm with a length of 2 m was selected to investigate the influence of the initial porosity on the gas drainage ...
The results suggest that the unknown function identification method for the differential equation, which avoids measurement and analysis of the pore and fissure structures of coal samples, accurately and directly obtains the change trend of desorptiondiffusion sources in the process of gas seepage and provides a new idea for the study of the ...
The amount of gas retained in coal depends on a number of factors such as the rank of coal, the depth of burial, the immediate roof and floor to the coal seam, geologic anomalies, tectonic pressures, and temperature prevailing at the end of the coalification process. In general, the higher the rank of coal and the greater the depth of coal seam ...
Gas 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 ...
Coal seam gas (CSG) is mainly a combination of methane (CH 4) and carbon dioxide and has very close methane percentage (95%) to that of natural gas (NG) (97%).In contrast biogas produced form digestion process has methane content around 68% which makes it low energy content as shown in Table to the decline in the NG resources and the low quality of biogas, CSG can be the energy resource ...
Coal seam gas is a natural gas held in coal seams under pressure by groundwater. Coal seam gas wells release the gas by reducing the pressure through groundwater extraction. Extracted water and gas is diverted to surface infrastructure treatment and processing plants (Figure 1). The extracted water is termed 'coproduced water' (also ...
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,2 Especially when it enters deep mining, stress and gas pressure rise markedly, while permeability of the coal seam becomes extremely low, which leads to a poor gas extraction ...
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.
The process of drilling holes to extract gas disrupts the coal seam's pressure equilibrium, causing the adsorbed gas in the pore space to desorb and become free gas, and the entire process to be transmitted to the fissure system via diffusionseepage [26,27,28]. The volume of gas exchange per unit volume between the coal matrix and the ...
Gas flow in a coal seam is a complex process due to the complicated coal structure and the sorption characteristics of coal to adsorbable gas (such as carbon dioxide and methane). It is essential to understand the gas migration patterns for different fields of engineering, such as CBM exploitation, underground coal mine gas drainage, and CO2 geosequestration. Many factors influence gas ...
Pad Drilling (Surat Basin) The majority of Arrow Energy's coal seams have Total Vertical Depths of less than 900 m and as shallow as 200 m. These shallow depths create a problem when planning well spacing for gas drainage. The optimum spacing required for vertical wells is between 700 and 1200 meters.
Coal seam gas extraction is an important part of green mining. At the same time gas injection for enhanced coalbed methane recovery (ECBM) has been proposed as an environmentally friendly, lowcarbon and effective technology to increase methane production. ... Model Ⅰ and Model Ⅱ characterize the gas diffusion process in coal particles in ...
Hydraulic fracturing, more commonly known as fracking or fraccing, is used to stimulate and accelerate the flow of coal seam gas. The process involves high pressured injection of sand, water and chemicals into the coal seam gas well. The injection causes fractures in the coal seam allowing the gas to flow to the surface of the well.
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