Gas pressure distribution in outcropping coal seams with allowance for degassing via adjoining rocks

1972 ◽  
Vol 8 (2) ◽  
pp. 170-182
Author(s):  
S. N. Osipov
Keyword(s):  
Pressure Distribution ◽  
Gas Pressure ◽  
Coal Seams

Gas pressure in coal seams

1966 ◽  
Vol 2 (5) ◽  
pp. 465-471 ◽  
Author(s):  
S. V. Kuznetsov
Keyword(s):  
Gas Pressure ◽  
Coal Seams

scholarly journals Analyses of In-situ Measurements of Gas Emission and Gas Pressure in Pre-drainage Boreholes in Coal Seams.

1993 ◽  
Vol 109 (5) ◽  
pp. 331-335
Author(s):  
Ken GOTOH ◽  
Tomohiro MURAKAMI ◽  
Hidefumi OHMUTA
Keyword(s):  
In Situ Measurements ◽  
Gas Pressure ◽  
Coal Seams ◽  
Gas Emission

Calculation of the fall in gas pressure during degassing of thin coal seams by large-diameter boreholes

1972 ◽  
Vol 8 (3) ◽  
pp. 291-295 ◽  
Author(s):  
V. V. Khodot ◽  
R. N. Isaeva ◽  
V. G. Krupenya
Keyword(s):  
Large Diameter ◽  
Gas Pressure ◽  
Coal Seams

Measurement of gas pressure in coal seams

1988 ◽  
Vol 24 (3) ◽  
pp. 181-199 ◽  
Author(s):  
S. A. Khristianovich ◽  
Yu. F. Kovalenko
Keyword(s):  
Gas Pressure ◽  
Coal Seams

scholarly journals Simulation of gas transport in a landfill with layered new and old municipal solid waste

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Tao Zhang ◽  
Jianyong Shi ◽  
Xun Wu ◽  
Hai Lin ◽  
Xiulei Li
Keyword(s):  
Municipal Solid Waste ◽  
Pressure Distribution ◽  
Solid Waste ◽  
Gas Transport ◽  
Transport Model ◽  
Gas Permeability ◽  
Gas Production ◽  
Gas Pressure ◽  
Anisotropy Ratio ◽  
The Difference

AbstractAverage biodegradation rate of newly filled municipal solid waste (MSW) in landfills is relatively fast, and the landfill gas produced by the new MSW biodegradation can cause great variations in gas pressure. To predict the gas pressure distribution in the MSW layer, a one-dimensional gas transport model is established in this study. The following factors are considered in this model: (1) the variation of gas permeability with depth; (2) the anisotropy ratio of gas permeability; (3) the settlement caused by waste biodegradation. Furthermore, a single peak model for gas production is applied as the source term of gas production. The equation for settlement caused by waste biodegradation is presented, and the time of peak gas production rate is obtained by fitting the settlement of the newly filled layer. The stratification of the unsaturated and saturated regions is taken into account by distinguishing the difference in gas saturation. The layering of the new and old waste layers is considered by distinguishing the difference in the length of time that waste has been degraded to produce gas. Based on the method of numerical calculation, the gas pressure distribution in the landfill with layered new and old MSW is well simulated. The position where the maximum gas pressure occurs is found. The sensitivity analysis shows that the influence of the anisotropy ratio on gas pressure distribution is more significant.

scholarly journals Experimental Study on Adsorption Pore Structure and Gas Migration of Coal Reservoir Using Low-Field Nuclear Magnetic Resonance

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Jiazhuo Li ◽  
Penghui Guo ◽  
Wenhao Xie ◽  
Jiaqi Chu ◽  
Zhiqiang Yin ◽  
...  
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Pore Structure ◽  
Methane Adsorption ◽  
Gas Pressure ◽  
Low Permeability ◽  
Coal Seams ◽  
Low Field ◽  
Tectonic Coal

For the quantitative recognition and characterization of the flow characteristics of polymorphism coalbed gas in tectonic coal, experiments on pore morphology, pore diameter distribution, and methane adsorption law in outburst tectonic coal were carried out by field emission scanning electron microscopy and low-field nuclear magnetic resonance. The results revealed abundant round and dense “pyrolysis pores” in outburst tectonic coals, most of which were adsorption and seepage pores, with micropores accounting for 78.2%. Most pores were independent and formed the network pore space for gas enrichment and migration in outburst tectonic coal. The transverse relaxation time (T2) of methane adsorption in tectonic coal and crushed outburst tectonic coals presented three peaks, namely, adsorption, drifting, and free peaks. The isolation of nanopores and micropores revealed lower adsorption capacity of outburst tectonic coal than that of crushed outburst tectonic coal. The gas staged adsorption of raw coal with outburst tectonic low-permeability was observed. Under low gas pressure, the T2 spectral peak area of methane adsorption increased remarkably, whereas that of desorbed methane increased slightly. As gas pressure was increased to a certain numerical value, the increment of methane adsorption decreased and tended to reach equilibrium. This finding reflected that methane adsorption tended to be saturated after gas pressure reached a certain value, but desorbed methane in isolated micropores increased quickly. The quantitative recognition and characterization of pore structure and gas adsorption in tectonic low-permeability outburst coal seams based on low-field magnetic resonance imaging provide an experimental method for gas exploitation in coal seams and the study and control of coal and gas outburst mechanism.

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