Gas pressure in coal seams

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

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

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 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.

Analysis of gas-pressure measurements in coal seams in connection with the manifestation of permeability around holes and mine workings

1998 ◽  
Vol 34 (2) ◽  
pp. 113-118 ◽  
Author(s):  
S. V. Kuznetsov ◽  
V. A. Trofimov
Keyword(s):  
Gas Pressure ◽  
Pressure Measurements ◽  
Coal Seams ◽  
Mine Workings

scholarly journals A New Method for the Measurement of Gas Pressure in Water-Bearing Coal Seams and Its Application

Geofluids ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Xiao Cui ◽  
Jiayong Zhang ◽  
Liwen Guo ◽  
Xuemin Gong
Keyword(s):  
Coal Seam ◽  
Field Experiments ◽  
Water Pressure ◽  
Direct Methods ◽  
Gas Pressure ◽  
New Method ◽  
Well Testing ◽  
Coal Seams ◽  
Coal Seam Gas ◽  
Gas Disaster

Coal seam gas pressure is one of the fundamental parameters used to assess coal seam gas occurrence and is an important index in assessing the risk of gas disaster. However, the geological characteristics of coal seams become increasingly complex with increasing mining degree, thus decreasing the accuracy and success rate of direct methods for measuring gas pressure. To address such issues, we have developed a new method for direct measurement of gas pressure in water-bearing coal seams. In particular, we developed a pressure measurement device based on theoretical analysis and quantified the basic parameters of the device based on well testing. Then, we verified the applicability of our method based on comparative analysis of the results of field experiments and indirect measurements. Our results demonstrate that this new method can resolve the effects of water pressure, coal slime, and other factors on the estimation of gas pressure. The performance of this new method is considerably better than that of traditional methods. In particular, field test results demonstrate that our method can accurately and efficiently measure gas pressure in water-bearing coal seams. These results will be of great significance in the prevention and control of coal seam gas disaster.

scholarly journals Numerical Investigation of Complex Thermal Coal-Gas Interactions in Coal-Gas Migration

2018 ◽  
Vol 2018 ◽  
pp. 1-9
Author(s):  
Xiaoyan Ni ◽  
Peng Gong ◽  
Yi Xue
Keyword(s):  
Coal Seam ◽  
Variable Temperature ◽  
Gas Pressure ◽  
Gas Migration ◽  
Coal Seams ◽  
Coal Seam Gas ◽  
Coal Gas ◽  
Thermal Coal ◽  
Gas Seepage ◽  
Gas Interactions

Understanding the influence of temperature on the gas seepage of coal seams is helpful to achieve the efficient extraction of underground coal seam gas. Thermal coal-gas interactions involve a series of complex interactions between gas and solid coal. Although the interactions between coal and gas have been studied thoroughly, few studies have considered the temperature evolution characteristics of coal seam gas extraction under the condition of variable temperature because of the complexity of the temperature effect on gas drainage. In this study, the fully coupled transient model combines the relationship of gas flow, heat transfer, coal mass deformation, and gas migration under variable temperature conditions and represents an important nonlinear response to gas migration caused by the change of effective stress. Then, this complex model is implemented into a finite element (FE) model and solved through the numerical method. Its reliability was verified by comparing with historical data. Finally, the effect of temperature on coal permeability and gas pressure is studied. The results reveal that the gas pressure in coal fracture is generally higher than that in the matrix blocks. The higher temperature of the coal seam induces the faster increase of the gas pressure. Temperature has a great effect on the gas seepage behavior in the coal seams.

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