The inverse correlations between methane content and elastic parameters of coal-bed methane reservoirs

Geophysics ◽  
2013 ◽  
Vol 78 (4) ◽  
pp. D237-D248 ◽  
Author(s):  
Xin-Ping Chen ◽  
Quanming Huo ◽  
Jiandong Lin ◽  
Yang Wang ◽  
Fenjin Sun ◽  
...  
Keyword(s):  
Methane Content ◽  
Coal Bed ◽  
Coal Bed Methane ◽  
Biot Theory ◽  
Elastic Parameters ◽  
Gas Reservoirs ◽  
Coal Beds ◽  
Amplitude Versus Offset ◽  
Environmental Variations ◽  
Amplitude Versus

We investigated three coal-bed methane (CBM) reservoirs in which there exist, when we are careful about data quality and reduce environmental variations, inverse correlations between methane content and the elastic properties of the coal beds. Such inverse correlations may exist in general in high- and medium-rank CBM reservoirs. There is evidence that supports the generalization of such inverse correlations and factors that distort them. These distorting factors may prevent identification of such inverse correlations in certain CBM prospects; however, they cannot negate the underlying inverse correlations. Such inverse correlations may play a role in CBM amplitude versus offset (AVO) similar to the role played by Gassmann-Biot theory ( Gassmann, 1951 ; Biot, 1956 , 1962 ) in AVO technology for conventional gas reservoirs. This may lay the first brick for a theoretical basis of CBM AVO.

Theory of CBM AVO: I. Characteristics of anomaly and why it is so

Geophysics ◽  
2014 ◽  
Vol 79 (2) ◽  
pp. D55-D65 ◽  
Author(s):  
Xin-Ping Chen ◽  
Quanming Huo ◽  
Jiandong Lin ◽  
Yang Wang ◽  
Fenjin Sun ◽  
...  
Keyword(s):  
Coalbed Methane ◽  
Methane Content ◽  
Poisson's Ratio ◽  
Elastic Parameters ◽  
Zoeppritz Equations ◽  
Amplitude Versus Offset ◽  
Study Characteristics ◽  
Amplitude Versus ◽  
Class Iv ◽  
Sweet Spots

Based on the inverse correlations between methane content and elastic parameters of coalbed methane (CBM) reservoirs and on geomodulus approximation of Zoeppritz equations, we study characteristics of CBM amplitude versus offset (AVO) anomaly. Our research first suggests that CBM AVO cannot, and needs not, cling to Poisson’s Ratio as AVO for conventional gas (C-gas) does and that various approximations of Zoeppritz equations for C-gas AVO can be applied to CBM AVO though the elastic contrasts at boundaries of CBM reservoirs cannot be said to be small compared to unity. We then show that the sweet spots within a brine-saturated high- and/or medium-rank CBM reservoir can have only Class IV AVO anomaly. The reason is that all of the three elastic reflectivities, i.e., [Formula: see text] reflectivity, [Formula: see text] reflectivity, and [Formula: see text] reflectivity, at one and the same boundary of a CBM reservoir, are always of the same sign and that [Formula: see text] reflectivity or density reflectivity or both are significant in comparison with [Formula: see text] reflectivity. Finally, we propose that density reflectivity be an indicator of methane content of a CBM reservoir whereas [Formula: see text] reflectivity should be an indicator of permeability.

Seismic studies of coal bed methane content in the west coal mining area of Qinshui Basin

2013 ◽  
Vol 23 (6) ◽  
pp. 795-803 ◽  
Author(s):  
Guangui Zou ◽  
Suping Peng ◽  
Caiyun Yin ◽  
Yanyong Xu ◽  
Fengying Chen ◽  
...  
Keyword(s):  
Coal Mining ◽  
Mining Area ◽  
Methane Content ◽  
Coal Bed ◽  
Coal Bed Methane ◽  
The West ◽  
Qinshui Basin ◽  
Coal Mining Area

Study on logging interpretation of coal-bed methane content based on deep learning

2019 ◽  
Vol 67 (2) ◽  
pp. 589-596
Author(s):  
Parhat Zunu ◽  
Min Xiang ◽  
Fengwei Zhang
Keyword(s):  
Deep Learning ◽  
Methane Content ◽  
Coal Bed ◽  
Coal Bed Methane

scholarly journals Estimation of Coal Bed Methane Content in Coal Seams.

1994 ◽  
Vol 110 (12) ◽  
pp. 939-945
Author(s):  
Kotaro OHGA ◽  
Kiyoshi HIGUCHI ◽  
Kazutaka HIGUCHI
Keyword(s):  
Methane Content ◽  
Coal Bed ◽  
Coal Bed Methane ◽  
Coal Seams

Research on Main Control Factors of Coalbed Methane Reservoir Formation in Turpan-Hami Basin

2011 ◽  
Vol 233-235 ◽  
pp. 2201-2204 ◽  
Author(s):  
Gui Zhong Li ◽  
Hong Yan Xu ◽  
Bo Wang ◽  
Ze Deng ◽  
Meng Geng
Keyword(s):  
Coalbed Methane ◽  
Structural Evolution ◽  
Coal Bed ◽  
Coal Rank ◽  
Hydrogeological Condition ◽  
Gas Reservoirs ◽  
Coal Resources ◽  
Coal Beds ◽  
Control Factors ◽  
Coalbed Methane Reservoir

Turpan-Hami Basin is a typical low coal rank coal bearing basin in China, with coal resources accounting for 50% of the total low coal rank resources. Structural evolution of the basin plays important controlling roles to generation；Fan delta and braided delta deposit systems are thick and stable sedimentary systems which are favorable for coal beds development；Hydrogeological condition is a major force for the adjustment and construction of coal-bed gas reservoirs.

THE JANSZ GAS FIELD, CARNARVON BASIN, AUSTRALIA

2003 ◽  
Vol 43 (1) ◽  
pp. 303 ◽  
Author(s):  
C.C. Jenkins ◽  
D.M. Maughan ◽  
J.H. Acton ◽  
A. Duckett ◽  
B.E. Korn ◽  
...  
Keyword(s):  
Column Height ◽  
Gas Reservoirs ◽  
Gas Reservoir ◽  
Gas Field ◽  
Amplitude Versus Offset ◽  
Gas Markets ◽  
Sandstone Reservoir ◽  
Western Limb ◽  
Amplitude Versus ◽  
Carnarvon Basin

The Jansz gas field is located in permit WA-268-P, 70 km northwest of the Gorgon gas field in the Carnarvon Basin. The Jansz–1 discovery well was drilled in April 2000 and intersected 29 m of net gas pay in an Oxfordian age shallow marine sandstone reservoir. The well drilled a stratigraphic trap on the western limb of the Kangaroo Syncline.The Io–1 well was drilled in January 2001 in the adjacent permit WA-267-P (18 km from Jansz–1) and intersected the same Oxfordian sandstone reservoir penetrated by Jansz–1, with a total of 44 m of net gas pay. The Tithonian and the Upper Triassic Brigadier Sandstone gas reservoirs at Geryon–1 (1999) and Callirhoe–1 (2001) in WA-267-P are in pressure communication with the Oxfordian gas reservoir at Jansz–1 and Io–1. Consequently, the three different age reservoirs comprise a single gas pool, with a common gas/water contact.The Jansz gas field has been delineated by four wells and 2D seismic. The gas sandstones have a prominent amplitude versus offset response, which defines the field limits. The Jansz gas field is confirmed by drilling to be an areally extensive (2,000 km2) gas accumulation with a gross column height of 400 m and an estimated 20 TCF (566 G.m3) recoverable sales gas, which represents 40% of the discovered gas resources in the deepwater Carnarvon Basin. The size of the Jansz gas field and its remoteness from existing pipeline gas markets suggests that an export LNG project will be the basis for its development.

Computer Modeling of Coal Bed Methane Recovery in Coal Mines

2012 ◽  
Vol 134 (3) ◽  
Author(s):  
Jerzy Stopa ◽  
Stanisław Nawrat
Keyword(s):  
Methane Production ◽  
Pore Volume ◽  
Longwall Mining ◽  
Coal Bed ◽  
Coal Bed Methane ◽  
Methane Recovery ◽  
Coal Matrix ◽  
Coal Beds ◽  
The Matrix ◽  
Adjacent Fractures

This paper presents an improved reservoir simulation approach to methane production in a longwall mining environment. The coal beds are naturally fractured systems with the gas adsorbed into the coal matrix. Fractures penetrating the coal matrix have limited storage capacity, but they play the role of a gas transportation system. The proposed simulation technique is based on the assumption that a mass of coal removed by mining transfers its gas to adjacent fractures. By using an ECLIPSE coal bed methane simulator, the pore volume of the matrix represents the coal volume of the simulation cell. Consequently, the exploitation of coal can be simulated by modifying the matrix pore volume over time. This paper presents theoretical backgrounds of this approach and investigates numerical effects. A case study of the Moszczenica coal mine in Poland, including computer simulations of methane production, is also reported to show that a long history of the methane and coal recovery can be reproduced using the proposed technique.

Coal Bed Methane Reservoir in the Mengjin Coalfield, Henan Province, China

2013 ◽  
Vol 448-453 ◽  
pp. 1062-1065 ◽  
Author(s):  
Jin Jiang Lian ◽  
De Tian Yan ◽  
Biao Gao ◽  
Hai Yang Cao
Keyword(s):  
Coal Seam ◽  
Methane Content ◽  
Coal Bed ◽  
Coal Bed Methane ◽  
Burial Depth ◽  
Geological Exploration ◽  
Gas Reservoir ◽  
Unconventional Gas ◽  
The Past ◽  
Energy Demands

Coal is a continuous unconventional gas reservoir and coal bed methane has the potential to make an important contribution to the future energy demands. The second member coal seam of Shaxi Formation in the Mengjin coalfield is one of the most important methane bearing and exploration formations. Based on industrial analysis, elemental analysis and methane content test of thirty-five coal samples from the Mengjin coalfield, together with other geological data of the past five-year exploration, the factors that controlling the coal bed methane reservoir are identified in the Mengjin coalfield. The thick-bedded No. 2 coal seam, about 6 meters, of the Shaxi formation are continuous distributed in the Mengjin coalfield. The burial depth is from 400 to 800 meters, this is suitable for coal bed methane exploit. There is a trend which an increase in the degree of coalification is correlated with rise content of methane in No. 2 coal. Coal rank has a significant effect on the content of coal bed methane. The relationships between methane content and basin hydrodynamics are also described and discussed in this paper. The deep stagnant zone contains the largest coal bed methane accumulation. Future geological exploration for coal bed methane in Mengjin coalfield should be guided by the essential factors identified in this study. The application of them could benefit to solving the discrepancy between the amount of reserves and the question of their exploitability.

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