Abstract

Gas migration through coal matrix and cleats not only includes gas sorption and desorption but also leads to coal strain development. In this article, a series of experiments were carried out to investigate the strain development in four unconfined bituminous coal samples exposed to methane at various pressures. The dominant factors for sorption/desorption-induced deformation were associated with pore characteristics. Pore size distribution for all samples was determined by mercury intrusion porosimetry, nitrogen adsorption, and carbon dioxide adsorption techniques. The results show that there were differences in the pore surface area, pore shape, and pore size distribution of coal samples. Coal swelled when methane was injected and shrank when gas was released. The coal radial strains were always larger than axial strains at adsorption and desorption phases because the samples were drilled along coal cleat. The residual strain remaining after the adsorption–desorption cycle may be positive or negative. The strains of coal samples were different even with the same injected gas pressure. The total pore volume is not a dominant factor for sorption/desorption strain and rate. The pore size distribution and pore type also should be comprehensively considered.

References

1.
Xie
H.-P.
,
Zhou
H.-W.
,
Xue
D.-J.
,
Wang
H.-W.
,
Zhang
R.
, and
Gao
F.
, “
Research and Consideration on Deep Coal Mining and Critical Mining Depth (in Chinese)
,”
Journal of China Coal Society
37
(
2012
):
535
542
. https://doi.org/10.13225/j.cnki.jccs.2012.04.011
2.
Majewska
Z.
,
Ceglarska-Stefańska
G.
,
Majewski
S.
, and
Ziętek
J.
, “
Binary Gas Sorption/Desorption Experiments on a Bituminous Coal: Simultaneous Measurements on Sorption Kinetics, Volumetric Strain and Acoustic Emission
,”
International Journal of Coal Geology
77
, nos. 
1–2
(
2009
):
90
102
. https://doi.org/10.1016/j.coal.2008.09.009
3.
Warren
J. E.
and
Root
P. J.
, “
The Behavior of Naturally Fractured Reservoirs
,”
Society of Petroleum Engineers Journal
3
, no. 
3
(
2013
):
245
255
. https://doi.org/10.2118/426-PA
4.
Clarkson
C. R.
and
Bustin
R. M.
, “
Effect of Pore Structure and Gas Pressure upon the Transport Properties of Coal: A Laboratory and Modeling Study. 1. Isotherms and Pore Volume Distributions
,”
Fuel
78
, no. 
11
(
1999
):
1333
1344
. https://doi.org/10.1016/S0016-2361(99)00055-1
5.
Firouzi
M.
,
Rupp
E. C.
,
Liu
C. W.
, and
Wilcox
J.
, “
Molecular Simulation and Experimental Characterization of the Nanoporous Structures of Coal and Gas Shale
,”
International Journal of Coal Geology
121
(
2014
):
123
128
. https://doi.org/10.1016/j.coal.2013.11.003
6.
Lai
J.
and
Wang
G.
, “
Fractal Analysis of Tight Gas Sandstones Using High-Pressure Mercury Intrusion Techniques
,”
Journal of Natural Gas Science and Engineering
24
(
2015
):
185
196
. https://doi.org/10.1016/j.jngse.2015.03.027
7.
Clarkson
C. R.
,
Solano
N.
,
Bustin
R. M.
,
Bustin
A. M. M.
,
Chalmers
G. R. L.
,
He
L.
,
Melnichenko
Y. B.
,
Radliński
A. P.
, and
Blach
T. P.
, “
Pore Structure Characterization of North American Shale Gas Reservoirs Using USANS/SANS, Gas Adsorption, and Mercury Intrusion
,”
Fuel
103
(
2013
):
606
616
. https://doi.org/10.1016/j.fuel.2012.06.119
8.
Zhao
Y.
,
Liu
S.
,
Elsworth
D.
,
Jiang
Y.
, and
Zhu
J.
, “
Pore Structure Characterization of Coal by Synchrotron Small-Angle X-Ray Scattering and Transmission Electron Microscopy
,”
Energy & Fuels
28
, no. 
6
(
2014
):
3704
3711
. https://doi.org/10.1021/ef500487d
9.
Zang
J.
,
Wang
K.
, and
Zhao
Y.
, “
Evaluation of Gas Sorption-Induced Internal Swelling in Coal
,”
Fuel
143
(
2015
):
165
172
. https://doi.org/10.1016/j.fuel.2014.11.007
10.
Pan
J.
,
Wang
K.
,
Hou
Q.
,
Niu
Q.
,
Wang
H.
, and
Ji
Z.
, “
Micro-Pores and Fractures of Coals Analysed by Field Emission Scanning Electron Microscopy and Fractal Theory
,”
Fuel
164
(
2016
):
277
285
. https://doi.org/10.1016/j.fuel.2015.10.011
11.
Viljoen
J.
,
Campbell
Q. P.
,
le Roux
M.
, and
De Beer
F.
, “
An Analysis of the Slow Compression Breakage of Coal Using Microfocus X-Ray Computed Tomography
,”
International Journal of Coal Preparation and Utilization
35
, no. 
1
(
2014
):
1
13
. https://doi.org/10.1080/19392699.2014.907283
12.
Wu
D.
,
Liu
G.
,
Sun
R.
, and
Chen
S.
, “
Influences of Magmatic Intrusion on the Macromolecular and Pore Structures of Coal: Evidences from Raman Spectroscopy and Atomic Force Microscopy
,”
Fuel
119
(
2014
):
191
201
. https://doi.org/10.1016/j.fuel.2013.11.012
13.
Gray
I.
, “
Reservoir Engineering in Coal Seams: Part 2-Observations of Gas Movement in Coal Seams
,”
SPE Reservoir Engineering
2
, no. 
1
(
2013
):
35
40
. https://doi.org/10.2118/14479-PA
14.
Liu
J.
,
Chen
Z.
,
Elsworth
D.
,
Miao
X.
, and
Mao
X.
, “
Evaluation of Stress-Controlled Coal Swelling Processes
,”
International Journal of Coal Geology
83
, no. 
4
(
2010
):
446
455
. https://doi.org/10.1016/j.coal.2010.06.005
15.
van Bergen
F.
,
Spiers
C.
,
Floor
G.
, and
Bots
P.
, “
Strain Development in Unconfined Coals Exposed to CO2, CH4 and Ar: Effect of Moisture
,”
International Journal of Coal Geology
77
, nos. 
1–2
(
2009
):
43
53
. https://doi.org/10.1016/j.coal.2008.10.003
16.
Cui
X.
,
Bustin
R. M.
, and
Chikatamarla
L.
, “
Adsorption-Induced Coal Swelling and Stress: Implications for Methane Production and Acid Gas Sequestration into Coal Seams
,”
Journal of Geophysical Research: Solid Earth
112
, no. 
B10
(
2007
): B10202. https://doi.org/10.1029/2004JB003482
17.
Daines
M. E.
, “
Apparatus for the Determination of Methane Sorption on Coal at High Pressures by a Weighing Method
,”
International Journal of Rock Mechanics and Mining Sciences & Geomechanics Abstracts
5
, no. 
4
(
1968
):
315
323
. https://doi.org/10.1016/0148-9062(68)90003-X
18.
Reucroft
P. J.
and
Patel
H.
, “
Gas-Induced Swelling in Coal
,”
Fuel
65
, no. 
6
(
1986
):
816
820
. https://doi.org/10.1016/0016-2361(86)90075-X
19.
Wang
G. X.
,
Wei
X. R.
,
Wang
K.
,
Massarotto
P.
, and
Rudolph
V.
, “
Sorption-Induced Swelling/Shrinkage and Permeability of Coal under Stressed Adsorption/Desorption Conditions
,”
International Journal of Coal Geology
83
, no. 
1
(
2010
):
46
54
. https://doi.org/10.1016/j.coal.2010.03.001
20.
Levine
J. R.
, “
Model Study of the Influence of Matrix Shrinkage on Absolute Permeability of Coal Bed Reservoirs
,”
Geological Society Special Publication
109
, no. 
1
(
1996
):
197
212
. https://doi.org/10.1144/GSL.SP.1996.109.01.14
21.
Palmer
I.
, “
Permeability Changes in Coal: Analytical Modeling
,”
International Journal of Coal Geology
77
, nos. 
1–2
(
2009
):
119
126
. https://doi.org/10.1016/j.coal.2008.09.006
22.
Sander
H.
,
Peach
C. J.
, and
Spiers
C. J.
, “
Applied Stress Reduces the CO2 Sorption Capacity of Coal
,”
International Journal of Coal Geology
85
, no. 
1
(
2011
):
128
142
. https://doi.org/10.1016/j.coal.2010.10.010
23.
Mukherjee
M.
and
Misra
S.
, “
A Review of Experimental Research on Enhanced Coal Bed Methane (ECBM) Recovery via CO2 Sequestration
,”
Earth-Science Reviews
179
(
2018
):
392
410
. https://doi.org/10.1016/j.earscirev.2018.02.018
24.
Zhu
J.
,
Zhang
M.
,
Jiang
Y.-D.
, and
Tang
J.
, “
The Experimental Study of Coal Strain Induced by Carbon Dioxide Sorption/Desorption (in Chinese)
,”
Journal of China Coal Society
40
(
2015
):
1081
1086
. https://doi.org/10.13225/j.cnki.jccs.2014.0967
25.
Gan
H.
,
Nandi
S. P.
, and
Walker Jr
P. L.
, “
Nature of the Porosity in American Coals
,”
Fuel
51
(
1972
):
272
277
. https://doi.org/10.1016/0016-2361(72)90003-8
26.
Şenel
I. G.
,
Gürüz
A. G.
,
Yücel
H.
,
Kandas
A. W.
, and
Sarofim
A. F.
, “
Characterization of Pore Structure of Turkish Coals
,”
Energy & Fuels
15
, no. 
2
(
2001
):
331
338
. https://doi.org/10.1021/ef000081k
27.
Kaufmann
J.
,
Loser
R.
, and
Leemann
A.
, “
Analysis of Cement-Bonded Materials by Multi-Cycle Mercury Intrusion and Nitrogen Sorption
,”
Journal of Colloid and Interface Science
336
, no. 
2
(
2009
):
730
737
. https://doi.org/10.1016/j.jcis.2009.05.029
28.
Clarkson
C. R.
,
Freeman
M.
,
He
L.
,
Agamalian
M.
,
Melnichenko
Y.
,
Mastalerz
M.
,
Bustin
R. M.
,
Radliński
A. P.
, and
Blach
T. P.
, “
Characterization of Tight Gas Reservoir Pore Structure Using USANS/SANS and Gas Adsorption Analysis
,”
Fuel
95
(
2012
):
371
385
. https://doi.org/10.1016/j.fuel.2011.12.010
29.
Qu
Z.
,
Wang
G. G. X.
,
Jiang
B.
,
Rudolph
V.
,
Dou
X.
, and
Li
M.
, “
Experimental Study on the Porous Structure and Compressibility of Tectonized Coals
,”
Energy & Fuels
24
, no. 
5
(
2010
):
2964
2973
. https://doi.org/10.1021/ef9015075
30.
Hodot
B. B.
,
Coal and Gas Outburst
(
China Industry Press
,
1966
)
31.
Friesen
W. I.
and
Mikula
R. J.
, “
Fractal Dimensions of Coal Particles
,”
Journal of Colloid and Interface Science
120
, no. 
1
(
1987
):
263
271
. https://doi.org/10.1016/0021-9797(87)90348-1
32.
Li
Y.-H.
,
Lu
G. Q.
, and
Rudolph
V.
, “
Compressibility and Fractal Dimension of Fine Coal Particles in Relation to Pore Structure Characterisation Using Mercury Porosimetry
,”
Particle & Particle Systems Characterization
16
, no. 
1
(
1999
):
25
31
. https://doi.org/10.1002/(SICI)1521-4117(199905)16:1<25::AID-PPSC25>3.0.CO;2-T
33.
Li
W.
,
Liu
H. F.
, and
Song
X.
, “
Multifractal Analysis of Hg Pore Size Distributions of Tectonically Deformed Coals
,”
International Journal of Coal Geology
144–145
(
2015
):
138
152
. https://doi.org/10.1016/j.coal.2015.04.011
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