Coalbed methane (CBM) has arisen as one of the clean natural gas resources to supplement the demand for conventional hydrocarbons. A total of more than 17,000 wells were in production, and the estimated recoverable resource of CBM came to × 10 12 m 3 in China . Therefore, the development prospect of CBM is very broad.
Most coal has some methane (the main component of natural gas) trapped inside it. This methane is produced during the coal formation process and gets trapped on the surface of the coal in tiny pores and fractures. 1 Many coalbeds also contain large amounts of water; the pressure from this water keeps the methane in place. Coalbed methane is extracted by pumping out the water, which lowers the ...
CBM refers to methane that is found in and extracted from coal seams. It is formed during the coalification process, which is the transformation of organic plant material into coal. CBM is also known as coal seam methane or coal seam gas, and is widely considered an "unconventional" source of natural gas.
Coalbed methane (CBM), is also known as coalbed gas and coal seam gas/methane (CSG/CSM), which are terms refer ring to the unconventional natural gas resource stored in coal
Coalbed methane (or coal bed methane), which is also known with varying names such as coal seam gas, coalmine methane, coalbed gas, is a form of natural gas that is extracted from the coal beds. ... In the process of extraction of CBM, a large amount of salinized water is released into freshwater ecosystems. This could pose adverse impacts ...
In the process of coalbed methane extraction, the recovery rate through pressure reduction is low, usually less than 50%. However, gas injection into the reservoir not only maintains the pressure easily but also achieves the purpose of continuous extraction . In this regard, domestic and foreign personnel have conducted pilot tests in the ...
During the extraction process, the water block effect seriously affects methane extraction in a coalbed. Detonation wave fracturing technology can result in the formation of a stressconcentrated area in the coalbed, thus increasing the possibility of accidents. Thus, the efficiency of CBM recovery in a coalbed does not improve by much [11 ...
Coalbed methane resource development can not only reduce the natural emission of a greenhouse gas and ensure full energy utilization, but it can also allow safer coal mining and reduce the risk of underground disasters like gas and coal outbursts and fires from spontaneous combustion (Wang et al., 2012; Zou et al., 2020).
Coalbed methane is an abundant form of natural gas extracted from coal beds. Coalbed methane is viewed as a cleaner energy source versus petroleum and coal combustion because methane extraction, transport and use are more efficient and less polluting. However, coalbed methane contains high amounts of CO2 that induce solidification during liquefaction. Therefore, CO2 has to be reduced below 2% ...
The controversy surrounding coal bed methane extraction has to do with the use of water during the process and its impact on global climate change. Coal bed methane exploration involves pumping large volumes of water out of coal seams to reduce the hydrostatic pressure and liberate the gas.
Gas is stored in micropores on the coal surface in coalbed methane (CBM) reservoirs, mainly via adsorption 1, order to release CBM from the coal and produce gas through the cleat system, the ...
During the extraction process, the water block effect seriously affects methane extraction in a coalbed. Detonation wave fracturing technology can result in the formation of a stressconcentrated area in the coalbed, thus increasing the possibility of accidents. ... This indicated that the competitive adsorption between CO 2 and CH 4 was a ...
A method and system for recovering coalbed methane are disclosed. The method involves tunneling along a seam of coal to a point below a water table and at a depth below the water table sufficient for dissolved methane to be present in the water; separating a portion of the water containing dissolved methane while below the water table; reducing pressure on the separated portion for extracting ...
Figure 5 shows the variation of coalbed methane pressure with different initial coalbed permeability. As illustrated in Figure 5, the greater the initial coalbed permeability, the better the methane extraction effect of hydraulic fracturing the initial coalbed permeability k 0 = 5 t10 −17 m 2, 9 910 −17 m 2, 13 110 −17 m 2, 17 110 −17 m 2, after 3650 d of extraction, the ...
In this work, a fully coupled thermalhydraulicmechanical model with twophase flow for coalbed methane extraction was proposed including coal deformation, gas seepage, water seepage, and thermal transport governing equations. Different coupled models and the influence of several key factors on CBM extraction process were analyzed.
A method and system for recovering coalbed methane are disclosed. The method involves tunneling along a seam of coal to a point below a water table and at a depth below the water table sufficient for dissolved methane to be present in the water; separating a portion of the water containing dissolved methane while below the water table; reducing pressure on the separated portion for extracting ...
To study the effect of CO2 injection pressure on gas migration characteristics and coalbed methane (CBM) extraction, a platform for the experimental replacement of CH4 with CO2 was used to conduct experiments on the replacement of CH4 under different CO2 injection pressures and analyze the gas transport characteristics and CH4 extraction during the experiment. The results reveal that the rate ...
Introduction. China has abundant coalbed methane (CBM) resources [1], with a predicted value of about × 10 12 m the process of coal mining, the total amount of CBM discharged into the atmosphere reaches × 10 9 m 3 every year, accounting for about one third of the world's total mine emissions. The emission of coalbed methane not only pollutes the atmospheric environment, but ...
Coalbed methane (CBM) drainage in underground coal mining is of significance to guarantee mining process safety and bring valuable environmental benefits, as the drainage could help to eliminate methanerelated accidents, reduce greenhouse gas (GHG) emissions and provide a source of clean energy. Due to the manifold benefits, extensive investigations have been conducted on methane emissions ...
Coalbed methane production began in the 1980s; shale gas extraction is even more recent. The main enabling technologies, hydraulic fracturing and horizontal drilling, have opened up new areas for oil and gas development, with particular focus on natural gas reservoirs such as shale, coalbed and tight sands. Shale Gas Extraction.
Introduction. Coalbed methane (CBM), as a byproduct of coal, is a clean and highefficiency fuel [1], [2]. The energy released in the combustion of 1 m 3 of methane is million Joules, equivalent to the combustion of kg of standard coal. Although it is a highly efficient energy source, methane can also be the cause of serious disasters that kill hundreds of people every year in China [3].
Coal bed methane (CBM) is a primary clean energy source found in coal seams. The recovery ratio of CBM is very low, especially with ground extraction, due to the strong adsorption of CH4 on the ...
A deep understanding of the process of coalbed methane (CBM) extraction is of significance for both the unconventional energy supply and mine safety. The effects of stimulation patterns and thermal effects (including thermal shrinkage, nonisothermal sorption, and gas density change) significantly affect the CBM extraction thermal effects on CBM extraction have been ...
The extraction process of CBM involves the dewatering of coal seams, enabling the release of trapped methane gas [1].However, one of the primary challenges encountered during CBM production is the significant amount of water that accompanies the extracted gas [2].This water, known as produced water, poses a major problem in terms of treatment, disposal, and potential environmental impacts.
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 ...
energy sources, coal bed methane gas receives considerable attention for its potential as a good energy source. During the coalification process, methane gas is captured in the coal seams and later released during coal mining operations. Coal bed methane separation is crucial for both economic benefit and methane emission reduction.
Coalbed methane recovery is complex and involves methane desorption, diffusion, and seepage 67,68. Desorption is the initial stage of the whole methane migration process, which is one of the ...
Coalbed methane (CBM), which is one of the primary resources of natural gas, associates complex storage mechanisms and requires some advanced recovery techniques, rendering conventional reserve ...
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 ...
The commercial extraction of methane from coal beds is now well established in a number of countries throughout the world, including the USA, Australia, China, India and Canada. Because coal is almost pure carbon, its reservoir character is fundamentally different to conventional gas plays. Coalbed methane (CBM) forms as either biogenically or ...
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