Abstract

Estimating production in coal accurately is crucial for promoting the process of safe, efficient, and green coal mining. It has been gradually recognized that horizontal wells with multiple fractures are employed to develop the coal reservoir, which signifies that the linear flow regime will dominate for a rather long time. However, the traditional analysis approaches of transient linear flow regimes may yield the overestimation of coal reservoir property. In this work, a new analytical model was proposed to estimate the rate-transient of wells with multi-fractures in coal reservoir that produce at a constant flowing pressure, which considers multiple flow mechanisms. Especially, the matrix shrinkage effect caused by water extraction from microscopic pores was incorporated, which has never been investigated by current production analysis models. In comparison with the conventional reservoir, the advanced pseudo-pressure and pseudo-time equations incorporating earlier critical mechanisms were established, including the four effects of gas slippage, effective stress, and matrix shrinkage caused by gas desorption/water extraction. In addition, the excellent agreement between the predicted rate by the proposed model and field data was achieved to validate the reliability of proposed models. Furthermore, the sensitivity analysis was carried out to clarify the influence of a series of factors on the seepage mechanism and productivity curve. Results demonstrated that the matrix shrinkage effect caused by water extraction may increase the well production rate in coal reservoirs. Selecting one field case as an example, the production rate predicted by the red curve is obviously higher than that by the green curve, the average discrepancy yields around 39.5%. The relative humidity in the coal matrix will present a positive impact on well production performance. Taking a field case as an instance, when the relative humidity varies from 8% to 14%, the well production sharply increases by about 11.6%.

References

1.
Karacan
,
C.
, and
Warwick
,
P.
,
2019
, “
Assessment of Coal Mine Methane (CMM) and Abandoned Mine Methane (AMM) Resource Potential of Longwall Mine Panels: Example From Northern Appalachian Basin, USA
,”
Int. J. Coal Geol.
,
208
, pp.
37
53
.
2.
Shahid
,
M.
,
Noriah
,
B.
,
Yacoob
,
M.
, and
Inayat ullah
,
M.
,
2012
, “
Production and Enhancement of Hydrogen From Water: A Review
,”
ASME J. Energy Resour. Technol.
,
134
(
3
), p.
034002
.
3.
Miao
,
Y.
,
Zhao
,
C.
, and
Zhou
,
G.
,
2020
, “
New Rate-Decline Forecast Approach for Low-Permeability Gas Reservoirs With Hydraulic Fracturing Treatments
,”
J. Pet. Sci. Eng.
,
190
, p.
107112
.
4.
Miao
,
Y.
,
Zhao
,
C.
,
Wu
,
K.
, and
Li
,
X.
,
2019
, “
Analysis of Production Prediction in Shale Reservoirs: Influence of Water Film in Inorganic Matter
,”
J. Nat. Gas Sci. Eng.
,
63
, pp.
1
9
.
5.
Zhao
,
C.
,
Li
,
J.
,
Liu
,
G.
, and
Zhang
,
X.
,
2019
, “
Analysis of the Influence of Cement Sheath Failure on Sustained Casing Pressure in Shale Gas Wells
,”
J. Nat. Gas Sci. Eng.
,
66
, pp.
244
253
.
6.
Zou
,
M.
,
Wei
,
C.
,
Zhang
,
M.
, and
Lv
,
X.
,
2018
, “
Quantification of Gas and Water Transfer Between Coal Matrix and Cleat Network During Drainage Process
,”
ASME J. Energy Resour. Technol.
,
140
(
3
), p.
032905
.
7.
Miao
,
Y.
,
Li
,
X.
,
Zhou
,
Y.
,
Lee
,
J.
,
Sun
,
Z.
,
Chang
,
Y.
,
Wang
,
S.
, and
Hou
,
C.
,
2018
, “
A New Rate-Transient Analysis Model for Shale Gas Reservoirs Coupled the Effect of Slip Flow and Surface Diffusion
,”
Int. J. Heat Mass Transfer
,
124
, pp.
1
10
.
8.
Meng
,
X.
, and
Wang
,
J.
,
2019
, “
Production Performance Evaluation of Multifractured Horizontal Wells in Shale Oil Reservoirs: An Analytical Method
,”
ASME J. Energy Resour. Technol.
,
141
(
10
), p.
102907
.
9.
Wang
,
H.
,
2014
, “
Performance of Multiple Fractured Horizontal Wells in Shale Gas Reservoir With Consideration of Multiple Mechanisms
,”
J. Hydrol.
,
510
, pp.
299
312
.
10.
Meng
,
Y.
,
Wang
,
J. Y.
,
Li
,
Z.
, and
Zhang
,
J.
,
2018
, “
An Improved Productivity Model in Coal Reservoir and Its Application During Coalbed Methane Production
,”
J. Nat. Gas Sci. Eng.
,
49
, pp.
342
351
.
11.
Zhao
,
C.
,
Li
,
J.
,
Liu G
,
H.
, and
Zhang
,
X.
,
2020
, “
Analysis of Well Stress With the Effect of Natural Fracture Nearby Wellbore During Hydraulic Fracturing in Shale Gas Wells
,”
J. Pet. Sci. Eng.
,
188
, p.
106885
.
12.
Clarkson
,
C.
, and
Qanbari
,
F.
,
2016
, “
A Semi-analytical Method for Forecasting Wells Completed in Low Permeability, Undersaturated CBM Reservoirs
,”
J. Nat. Gas Sci. Eng.
,
30
, pp.
19
27
.
13.
Arps
,
J.
,
1945
, “
Analysis of Decline Curves
,”
Trans. AIME
,
160
(
01
), pp.
228
247
.
14.
Fetkovich
,
M.
,
1980
, “
Decline Curve Analysis Using Type Curves
,”
J. Pet. Technol.
,
32
(
06
), pp.
1065
1077
.
15.
Blasingame
,
T.
, and
Lee
,
W.
,
1986
, “
Variable-Rate Reservoir Limits Testing
,”
Paper Presented at the Society for Petroleum Engineers Permian Basin Oil and Gas Recovery Conference
,
Midland, TX
,
March
.
16.
Feng
,
D.
,
Li
,
X.
,
Wang
,
X.
,
Li
,
J.
,
Sun
,
F.
,
Sun
,
Z.
,
Zhang
,
T.
,
Li
,
P.
,
Chen
,
Y.
, and
Zhang
,
X.
,
2018
, “
Water Adsorption and Its Impact on the Pore Structure Characteristics of Shale Clay
,”
Appl. Clay Sci.
,
155
, pp.
126
138
.
17.
Zhang
,
T.
,
Javadpour
,
F.
,
Yin
,
Y.
, and
Li
,
X.
,
2020
, “
Upscaling Water Flow in Composite Nanoporous Shale Matrix Using Lattice Boltzmann Method
,”
Water Resour. Res.
,
56
, p.
e2019WR026007
.
18.
Huang
,
L.
,
Zhou
,
W.
,
Xu
,
H.
,
Wang
,
L.
,
Zou
,
J.
, and
Zhou
,
Q.
,
2021
, “
Dynamic Fluid States in Organic-Inorganic Nanocomposite: Implications for Shale Gas Recovery and CO2 Sequestration
,”
Chem. Eng. J.
,
411
, p.
128423
.
19.
Sun
,
Z.
,
Li
,
X.
,
Liu
,
W.
,
Zhang
,
T.
,
He
,
M.
, and
Nasrabadi
,
H.
,
2020
, “
Molecular Dynamics of Methane Flow Behavior Through Realistic Organic Nanopores Under Geologic Shale Condition: Pore Size and Kerogen Types
,”
Chem. Eng. J.
,
398
, p.
124341
.
20.
Nobakht
,
M.
,
Mattar
,
L.
,
Moghadam
,
S.
, and
Anderson
,
D.
,
2012
, “
Simplified Forecasting of Tight/Shale-Gas Production in Linear Flow
,”
J. Can. Pet. Technol.
,
51
(
06
), pp.
476
486
.
21.
Nobakht
,
M.
, and
Clarkson
,
C.
,
2012
, “
A New Analytical Method for Analyzing Linear Flow in Tight/Shale Gas Reservoirs: Constant-Rate Boundary Condition
,”
SPE Reservoir Eval. Eng.
,
15
(
01
), pp.
51
59
.
22.
Clarkson
,
C.
,
Nobakht
,
M.
,
Kaviani
,
D.
, and
Ertekin
,
T.
,
2012
, “
Production Analysis of Tight-Gas and Shale-Gas Reservoirs Using the Dynamic-Slippage Concept
,”
SPE J.
,
17
(
01
), pp.
230
242
.
23.
Nobakht
,
M.
,
Clarkson
,
C.
, and
Kaviani
,
D.
,
2012
, “
New and Improved Methods for Performing Rate-Transient Analysis of Shale Gas Reservoirs
,”
SPE Reservoir Eval. Eng.
,
15
(
03
), pp.
335
350
.
24.
van Bergen
,
F.
,
Pagnier
,
H.
, and
Krzystolik
,
P.
,
2006
, “
Field Experiment of Enhanced Coalbed Methane-CO2 in the Upper Silesian Basin of Poland
,”
Environ. Geosci.
,
13
(
3
), pp.
201
224
.
25.
van Bergen
,
F.
,
Spiers
,
C.
,
Floor
,
G.
, and
Bots
,
P.
,
2009
, “
Strain Development in Unconfined Coals Exposed to CO2, CH4 and Ar: Effect of Moisture
,”
Int. J. Coal Geol.
,
77
(
1–2
), pp.
43
53
.
26.
Liu
,
J.
,
Chen
,
Z.
,
Elsworth
,
D.
,
Qu
,
H.
, and
Chen
,
D.
,
2011
, “
Interactions of Multiple Processes During CBM Extraction: A Critical Review
,”
Int. J. Coal Geol.
,
87
(
3–4
), pp.
175
189
.
27.
White
,
C. M.
,
Smith
,
D. H.
,
Jones
,
K. L.
,
Goodman
,
A. L.
,
Jikich
,
S. A.
,
LaCount
,
R. B.
,
DuBose
,
S. B.
,
Ozdemir
,
E.
,
Morsi
,
B. I.
, and
Schroeder
,
K. T.
,
2005
, “
Sequestration of Carbon Dioxide in Coal With Enhanced Coalbed Methane Recovery a Review
,”
Energy Fuel
,
19
(
3
), pp.
659
724
.
28.
Pan
,
Z.
,
Connell
,
L. D.
,
Camilleri
,
M.
, and
Connelly
,
L.
,
2010
, “
Effects of Matrix Moisture on Gas Diffusion and Flow in Coal
,”
Fuel
,
89
(
11
), pp.
3207
3217
.
29.
Liu
,
W.
,
Hu
,
J.
,
Li
,
X.
,
Sun
,
F.
,
Sun
,
Z.
, and
Zhou
,
Y.
,
2018
, “
Research on Evaluation Method of Wellbore Hydrate Blocking Degree During Deepwater Gas Well Testing
,”
J. Nat. Gas Sci. Eng.
,
59
, pp.
168
182
.
30.
Day
,
S.
,
Sakurovs
,
R.
, and
Weir
,
S.
,
2008
, “
Supercritical Gas Sorption on Moist Coals
,”
Int. J. Coal Geol.
,
74
(
3–4
), pp.
203
214
.
31.
Gensterblum
,
Y.
,
Merkel
,
A.
,
Busch
,
A.
, and
Krooss
,
B. M.
,
2013
, “
High-pressure CH4 and CO2 Sorption Isotherms as a Function of Coal Maturity and the Influence of Moisture
,”
Int. J. Coal Geol.
,
118
, pp.
45
57
.
32.
Merkel
,
A.
,
Gensterblum
,
Y.
,
Krooss
,
B.
, and
Amann
,
A.
,
2015
, “
Competitive Sorption of CH4, CO2 and H2O on Natural Coals of Different Rank
,”
Int. J. Coal Geol.
,
150
, pp.
181
192
.
33.
Allardice
,
D. J.
, and
Evans
,
D. G.
,
1971
, “
The-brown Coal/Water System: Part 2. Water Sorption Isotherms on Bed-Moist Yallourn Brown Coal
,”
Fuel
,
50
(
3
), pp.
236
253
.
34.
Kaji
,
R.
,
Muranaka
,
Y.
,
Otsuka
,
K.
, and
Hishinuma
,
Y.
,
1986
, “
Water Absorption by Coals: Effects of Pore Structure and Surface Oxygen
,”
Fuel
,
65
(
2
), pp.
288
291
.
35.
Mu
,
R.
, and
Malhotra
,
V. M.
,
1991
, “
A New Approach to Elucidate Coal-Water Interactions by an In situ Transmission FT-IR Technique
,”
Fuel
,
70
(
10
), pp.
1233
1235
.
36.
Suárez
,
N.
,
Laredo
,
E.
, and
Nava
,
R.
,
1993
, “
Characterization of Four Hydrophilic Sites in Bituminous Coal by Ionic Thermal Current Measurements
,”
Fuel
,
72
(
1
), pp.
13
18
.
37.
Zhou
,
Y.
,
Sun
,
W.
,
Chu
,
W.
,
Liu
,
X.
,
Jing
,
F.
, and
Xue
,
Y.
,
2016
, “
Theoretical Insight Into the Enhanced CH4 Desorption via H2O Adsorption on Different Rank Coal Surfaces
,”
J. Energy Chem.
,
25
(
4
), pp.
677
682
.
38.
Suuberg
,
E. M.
,
Otake
,
Y.
,
Yun
,
Y.
, and
Deevi
,
S. C.
,
1993
, “
Role of Moisture in Coal Structure and the Effects of Drying Upon the Accessibility of Coal Structure
,”
Energy Fuel
,
7
(
3
), pp.
384
392
.
39.
Klinkenberg
,
L.
,
1941
, “
The Permeability of Porous Media to Liquids and Gases
,”
API Drilling and Production Practices
,
New York
,
January
, pp.
200
213
.
40.
King
,
G.
,
Ertekin
,
T.
, and
Schwerer
,
F.
,
1986
, “
Numerical Simulation of the Transient Behavior of Coal-Seam Degasification Wells
,”
SPE Form. Eval.
,
1
(
2
), pp.
165
183
.
41.
Wang
,
J.
,
Kabir
,
A.
,
Liu
,
J.
, and
Chen
,
Z.
,
2012
, “
Effects of Non-Darcy Flow on the Performance of Coal Seam Gas Wells
,”
Int. J. Coal Geol.
,
93
, pp.
62
74
.
42.
Vishal
,
V.
,
Singh
,
T.
, and
Ranjith
,
P.
,
2015
, “
Influence of Sorption Time in CO2-ECBM Process in Indian Coals Using Coupled Numerical Simulation
,”
Fuel
,
139
, pp.
51
58
.
43.
Ziarani
,
A.
,
Aguilera
,
R.
, and
Clarkson
,
C.
,
2011
, “
Investigating the Effect of Sorption Time on Coalbed Methane Recovery Through Numerical Simulation
,”
Fuel
,
90
(
7
), pp.
2428
2444
.
44.
Cui
,
X.
, and
Bustin
,
R.
,
2005
, “
Volumetric Strain Associated With Methane Desorption and its Impact on Coalbed gas Production From Deep Coal Seams
,”
AAPG Bull.
,
89
(
9
), pp.
1181
1202
.
45.
Connell
,
L.
,
Mazumder
,
S.
,
Sander
,
R.
,
Camilleri
,
M.
,
Pan
,
Z.
, and
Heryanto
,
D.
,
2016
, “
Laboratory Characterization of Coal Matrix Shrinkage, Cleat Compressibility and the Geomechanical Properties Determining Reservoir Permeability
,”
Fuel
,
165
, pp.
499
512
.
46.
Levine
,
J.
,
1996
, “
Model Study of the Influence of Matrix Shrinkage on Absolute Permeability of Coalbed Reservoirs
,”
Geol. Soc. Spec. Publ.
,
109
(
1
), pp.
197
212
.
47.
Zang
,
J.
, and
Wang
,
K.
,
2017
, “
Gas Sorption-Induced Coal Swelling Kinetics and Its Effects on Coal Permeability Evolution: Model Development and Analysis
,”
Fuel
,
189
, pp.
164
177
.
48.
Fry
,
R.
,
Day
,
S.
, and
Sakurovs
,
R.
,
2009
, “
Moisture-Induced Swelling of Coal
,”
Int. J. Coal Prep. Util.
,
29
(
6
), pp.
298
316
.
49.
Miao
,
Y.
,
Li
,
X.
,
Zhou
,
Y.
,
Wu
,
K.
,
Chang
,
Y.
,
Xiao
,
Z.
,
Wu
,
N.
, and
Lin
,
W.
,
2018
, “
A Dynamic Predictive Permeability Model in Coal Reservoir: Effects of Shrinkage Behavior Caused by Water Desorption
,”
J. Pet. Sci. Eng.
,
168
, pp.
533
541
.
50.
Moghadam
,
S.
,
Jeje
,
O.
, and
Mattar
,
L.
,
2011
, “
Advanced Gas Material Balance in Simplified Format
,”
J. Can. Pet. Technol.
,
50
(
01
), pp.
90
98
.
51.
Kang
,
S. S.
,
Datta-Gupta
,
A.
, and
Lee
,
W. J.
,
2013
, “
Impact of Natural Fractures in Drainage Volume Calculations and Optimal Well Placement in Tight Gas Reservoirs
,”
J. Pet. Sci. Eng.
,
109
, pp.
206
216
.
52.
Huang
,
L.
,
Khoshnood
,
A.
, and
Firoozabadi
,
A.
,
2020
, “
Swelling of Kimmeridge Kerogen by Normal-Alkanes, Naphthenes and Aromatics
,”
Fuel
,
267
, p.
117155
.
You do not currently have access to this content.