To produce coal seam gas (CSG), wells are drilled into underground coal seams, bringing water (CSG water) from the seams to the surface. This process reduces pressure in the seams which allows CSG to be released. The quality of CSG water quality varies greatly, however it is generally rich in salts and other minerals.
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 ...
The sealing quality of the gas extraction holes determines the extracted gas concentration. Based on this, the paper reveals the basic principle of hole sealing by analyzing the gas leakage mechanism of the borehole. The hole sealing technology of solidliquid materials with three pluggings and two injections for the gas extraction hole is proposed, and the hole sealing device and material ...
Coal 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.
For the gas extraction process, the larger the plastic zone created by the coal body around the borehole, the wider the range of fissures created and the greater the permeability, the more conducive to gas extraction and the increase in extraction rate. ... "Numerical Simulation of Gas Extraction in Coal Seam Strengthened by Static Blasting ...
When 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 ...
In this paper, using the continuumdiscontinuum element method (CDEM), the fragmentation and outburst process of coal specimen are simulated, and the main factors affecting coal breaking and outburst are explored. The results show that after the coal seam is uncovered, coal generates obvious failure and outburst trend. Near coalfree surface, the fracture coal blocks generate significant ...
As 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 ...
A coal mining car at Lackawanna Coal Mine in Scranton, Pennsylvania Coal miners exiting a winder cage at a mine near Richlands, Virginia in 1974 Surface coal mining in Wyoming, A coal mine in Frameries, Belgium. Coal mining is the process of extracting coal from the ground or from a mine. Coal is valued for its energy content and since the 1880s has been widely used to generate electricity.
Enhanced coal bed methane recovery using gas injection can provide increased methane extraction depending on the characteristics of the coal and the gas that is used. Accurate prediction of the extent of gas adsorption by coal are therefore important. Both experimental methods and modeling have been used to assess gas adsorption and its effects, including volumetric and gravimetric techniques ...
CBM is also known as virgin 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.
Low 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.
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].
Within 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
Liquefied natural gas (LNG) is a natural gas that has been cooled to minus 162°C, a process that is commonly done for gas export purposes as it reduces the volume of the transported gas. ... Conventional gas Coal seam gas; Cumulative production Reserves (2P) Resources (2C) Cumulative production Reserves (2P) Resources (2C) Adavale: 9: 12: 0: 0 ...
CSG 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.
1 Introduction. Recovery of coalbed methane (CBM) from coal seams can not only benefit mining safety, reduce greenhouse gas emissions, and also increase clean energy supply (Karacan et al., 2011; Moore, 2012).In the Junggar Basin, the CBM resources have been estimated at trillion cubic meters, which is the third largest CBM basin in China after the Qinshui Basin and Ordos Basin (Fu et al ...
Coal seam predrainage technology is widely used to prevent and control gas in China's highgas coal seams, and upward drilling is a safe and reliable technology. Using the Luling Coal Mine as the study location, according to the actual situation of the site, a layerthrough drilling process was proposed. Relying on a crosslayer extraction borehole, coal seam water injection efficiency ...
Several gas extraction enhancing methods have been proposed to improve the gas flow rate and reduce the gas pressure in coal seam, such as CO 2 or gas mixture injection enhanced CH 4 recovery, acid injection for permeability improvement, hydraulic flushing, hydraulic fracturing, etc,. The largediameter drilling expands the contact area between ...
Coal seam gas, also known as coalbed methane (CBM), is a natural gas that is often found trapped within coal deposits deep below the Earth's surface. The process of extracting CSG involves drilling into the coal seams and capturing the gas for commercial use.
This hole collapse leads to a failure to seal the hole and effectively extract the C 4, C 3, and C 2 coal seam gas from the upper part of the C 7+8 coal seam, making it difficult to ensure that the C 2 coal seam gas extraction process meets the required standard. Based on this, the crosslayer hole expansion and permeability enhancement ...
For mines with low permeability and high gas emissions, static blasting technology is used to presplit the coal seam to increase the permeability and strengthen the gas extraction, which will significantly reduce the occurrence of gas accidents in mines. Taking Wangjialing Coal Mine as the research object, the mathematical model of fluidsolid is established. The numerical simulation software ...
1. Introduction Coalbed methane (CBM) is an important associated resource, which is generated during the coal formation process and stored within the coal seam. Since coal has gradually entered the deep mining stage, its geology has become more complex, and its properties of low permeability are becoming more prominent.
In order to reveal the process and mechanism of gas flow in a lowpermeability coal seam, a new multiplerelaxationtime lattice Boltzmann method (MRTLBM) model of gas migration in coal micro/nanopores based on Langmuir monolayer adsorption theory, the slip boundary scheme and Bosanquet effective viscosity was established. The software MATLAB was used to carry out the simulation study of ...
Download scientific diagram | Coal seam gas production process (created by the author using data from Rice and Nuccio 2000) from publication: A study on the carbon dioxide injection into coal seam ...
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