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 determines precise hole placement spacing for a coal ...
WhatsApp: +86 18203695377
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 18203695377
Previous 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 18203695377
Coal 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 18203695377
From this, the primary equipment and key production technologies were determined for the proposed softrock protective seam mining. Finally, in combination with the optimal arrangement of the working face, the pressurerelief gas extraction technology accomplished the pressurerelief mining of the protected coal seam. 2.
WhatsApp: +86 18203695377
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.
WhatsApp: +86 18203695377
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 ...
WhatsApp: +86 18203695377
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 ...
WhatsApp: +86 18203695377
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.
WhatsApp: +86 18203695377
Fig. 1 Schematic of gas within a coal seam (Williams et al. 2013 ). Coal seam gas is trapped in pores and micropores, in the form of free or adsorbed gas. By reducing the hydraulic pressure, which is exerted via water and overlying aquifers to the seam, the gas is extracted through drilled wells.
WhatsApp: +86 18203695377
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.
WhatsApp: +86 18203695377
A 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 ...
WhatsApp: +86 18203695377
Integrated coal production and gas extraction must be considered as a system which involves the exploration and measurement of stress field redistribution, deformation and failure of coal and rock, gas pressure and permeability, and gas desorption and migration during the process of coal mining. Fundamental theory
WhatsApp: +86 18203695377
The method of predicting whether it is an outburst danger zone stipulated in the "Coal and Gas Outburst Prevention Rules" is based on the coal seam gas pressure of MPa and the content of 8 m 3 / t as the critical value. Reducing the gas pressure of coal seam to MPa during the extraction process is an important discriminant index.
WhatsApp: +86 18203695377
How gas extraction can unearth cleaner energy sources Monash Lens While fracking is highly controversial, the lessons from pursuing coal seam gas are already helping us understand and improve on a form of renewable energy also found deep underground geothermal energy. Read more at Monash Lens.
WhatsApp: +86 18203695377
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 ...
WhatsApp: +86 18203695377
Coalmeasure 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 18203695377
In the process of coal mine gas extraction, it is necessary to ensure the effective gas extraction in all directions in the mine so as to prevent and control the gas disaster. ... Xiaocun C, Hui T (2018) Technical scheme and application of pressurerelief gas extraction in multicoal seam mining region. Int J Min Sci Technol 28(3):483489 ...
WhatsApp: +86 18203695377
Gas transport mechanism during coalbed gas extraction process . ... the coal seam with low gas content and without outburst risk is chosen as the first coal seam to be mined. As shown in Figure 13, the rock mass moved to the gob after the first coal seam was mined. Then, it formed three zones above the mining coal seam: caving zone, fractures ...
WhatsApp: +86 18203695377
Based 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 18203695377
Coal seam gas extraction is not only a source of clean and natural energy but also a means to address the pressing issue of gas control . Undoubtedly, methane, a crucial element of coal mine gas, is a potent greenhouse gas [ 8 ].
WhatsApp: +86 18203695377
In order to solve the problem that the gas in the upper corner is easy to exceed the limit in the mining process of the deep outburst coal seam. Based on the theory of "Oring" and the distribution of stratigraphy in the field, the development law of mining fissures in the overlying rock layer during the workface retrieval was studied by combining theoretical calculation and ...
WhatsApp: +86 18203695377
5. Conclusion. (1) An improved coupled modeling method for coalbed methane extraction after hydraulic fracturing is proposed. It mainly includes two parts: hydraulic fracturing modeling and coupling modeling for coalbed methane extraction. In the first part, we introduce a state damage variable based on damage mechanics theory to record the ...
WhatsApp: +86 18203695377
Coal is affected by the concentrated stress disturbance of mining, the disturbance of drilling hole formation, and the concentrated stress of coal shrinkage and splitting of gas desorption from the hole wall; these result in a large number of secondary cracks that collect and leak gas. As a result, it is difficult for the coal seam sealing process to meet engineering quality sealing ...
WhatsApp: +86 18203695377
The China national coal mining depth is going deeper and deeper as the average annual rate of 1050 m [20].The mining depth of many coal mines in MidEast of China has reached m below surface ( 800 m in Huaibei, 850 m in Huainan, and 1000 m in Xuzhou).At these mining depths, the coal seam overburden stress ranges from 22 to 33 MPa and the coal seam gas pressure and gas content ...
WhatsApp: +86 18203695377
Environmental impact of coal mining and coal seam gas production on surface water quality in the Sydney basin, Australia. Environ Monit Assess. 2017 Aug;189(8):408. doi: /s . It also contributes to greenhouse gas emissions, both through the direct release of methane during extraction and the burning of the gas for energy.
WhatsApp: +86 18203695377
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
WhatsApp: +86 18203695377
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 supercharginggasliquid mass transfer", and microscopic ...
WhatsApp: +86 18203695377
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 ...
WhatsApp: +86 18203695377
In fact, 20 times the amount of energy you would do from a similar coal seam gas extraction process. MARK HORSTMAN: ... View the clip 'Coal seam gas production' for more information.
WhatsApp: +86 18203695377
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.
WhatsApp: +86 18203695377
The 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 18203695377
Dear 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 18203695377
A material supplier from Belgium would like to produce limestone powder for his custome...
India is rich in various mineral resources and it is an important mineral processing market
Copyright © 2023 GMC Co., Ltd. SiteMap
