The efficient preextraction and extraction of coal seam gas resources can not only reduce gas disasters, but also play an essential role in optimising China's energy structure and contributing to "carbon neutrality" [1,2].At present, requirements of "four" extraction management steps (extraction maximisation, extraction standardisation, extraction refinement, and extraction ...
WhatsApp: +86 18838072829As 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 ...
WhatsApp: +86 18838072829Coal is a black or brownishblack sedimentary rock that can be burned for fuel and used to generate is composed mostly of carbon and hydrocarbons, which contain energy that can be released through combustion (burning). Coal is the largest source of energy for generating electricity in the world, and the most abundant fossil fuel in the United States.
WhatsApp: +86 18838072829This study used computer simulation to select appropriate process designs to make coal seam gas (CSG) associated water comply with beneficial reuse regulations. ... 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 18838072829water. This releases natural gas from the coal. The gas and water are separated and the gas is piped to compression plants for transportation via gas transmission pipelines. In some cases hydraulic fracturing, or 'fracking', is used to extract coal seam gas. Hydraulic fracturing is the process of injecting fluid under high pressure into a coal
WhatsApp: +86 18838072829Gas preextraction technology in a coal reservoir can not only reduce greenhouse gas (GHG) emissions but also effectively recover coalbed methane (CBM). In this work, we use a geomechanicalcoupled gas flow (GCF) model to simulate and analyze the preextraction effect of a miningdisturbed coal seam. First, the simulation results of the GCF model are compared with field test data to verify the ...
WhatsApp: +86 18838072829Coalmeasure gas refers to a set of coalbed methane, coalmeasure shale gas (includes shale gas and certain coalderived gas, abbreviated as shale gas), and tight sandstone gas that are linked ...
WhatsApp: +86 18838072829The selection of proppants is critical in the coal seam gas extraction process, where the softer coal rock surface restricts the use of high strength proppants due to its vulnerability of embedding into the surface. 2) coal properties elastic modulus of coal is the most important factor deciding the proppant behaviour in the extraction ...
WhatsApp: +86 18838072829CBM 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.
WhatsApp: +86 188380728291. Introduction. The efficient extraction of gas ensures the safe production of coal mines. It also contributes to clean energy and reduces methane emissions in the process of coal mining. 1,2 In fact, it can be used as a carbon emission reduction approach for coal enterprises and a positive response to the goal of "carbon peaking and carbon neutrality".
WhatsApp: +86 18838072829For 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 ...
WhatsApp: +86 18838072829In 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 ...
WhatsApp: +86 18838072829In order to improve the efficiency of gas extraction in coal mines, a datadriven finemanagement and control method for gas extraction is proposed. Firstly, the accurate prediction of coal seam thickness and gas content was used to evaluate the gas reserves. Based on the time relationship between mining activities and gas extraction, the calculation model of borehole distance in different ...
WhatsApp: +86 18838072829Dear Colleagues, Coal seam gas is primarily made up of methane gas, generally 9598%. This gas is also called coal bed methane (CBM) if extracted from a coal deposit as unconventional natural gas for economic purposes. Coal mine methane (CMM) must be captured for safety reasons and should be utilized.
WhatsApp: +86 18838072829Download Coal seam gas extraction and coproduced water (PDF ) What is coproduced water? 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.
WhatsApp: +86 18838072829Within 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
WhatsApp: +86 18838072829The 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 ...
WhatsApp: +86 18838072829sitional flow for the premining coal seam gas extraction. Yang et al. [13] combined the evolution of stress, damage, and gas permeability with the deformation of coal and rock. Gao et al. [14] and Liu et al. [15] considered the thermal effect for extraction of coal seam gas with slotted boreholes.
WhatsApp: +86 18838072829Coal 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.
WhatsApp: +86 188380728291. 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.
WhatsApp: +86 18838072829Previous research on protective seam mining and pressure relief gas extraction technology, found that any slight expansion and deformation of the coal seam causes a dramatic increase in the permeability coefficient of the coal seam (Yin et al., 2015). Therefore, increasing a coal seam's permeability can be achieved by enlarging the permeable ...
WhatsApp: +86 18838072829Based on the basic geological data and production data of coalbed methane wells in the Shouyang Block, the characteristics and influencing factors of coalbed methane well production were analyzed, and the primary controlling factors were identified by the grey correlation method. The results show that the average daily gas production of the coalbed methane wells in the study area for the ...
WhatsApp: +86 18838072829Water contamination is a significant concern when it comes to coal seam gas extraction. The process involves injecting large volumes of water, mixed with chemicals, into the ground to release the gas. This can potentially contaminate underground water sources, leading to environmental and health risks for nearby communities. ...
WhatsApp: +86 18838072829Coal 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.
WhatsApp: +86 18838072829Coal Seam Gas Extraction by Integrated Drillings and Punchings from the Floor Roadway considering HydraulicMechanical Coupling Effect Geofluids / 2022 / Article Special Issue NonAqueous Fracturing for Unconventional Oil, Gas, and Geothermal Reservoirs View this Special Issue Research Article | Open Access
WhatsApp: +86 18838072829A large amount of CH 4 gas is stored in coal matrixes through the adsorption process at greater pore fluid pressure. As a result, when the pore pressure reduces to cause the desorption process to desorb this stored CH 4 gas, the CH 4 gas can be continuously produced. To reduce the pore fluid pressure, first naturally remaining pore water is pumped out through a drilled well and then along with ...
WhatsApp: +86 18838072829A 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 models ...
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