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Hindawi Publishing Corporation Journal of Petroleum Engineering Volume 2013, Article ID 803706, 8 pages http://dx.doi.org/10.1155/2013/803706 Research Article A Field Study on Simulation of CO 2 Injection and ECBM Production and Prediction of CO 2 Storage Capacity in Unmineable Coal Seam Qin He, Shahab D. Mohaghegh, and Vida Gholami Department of Petroleum and Natural Gas Engineering, West Virginia University, Morgantown, WV 26505, USA Correspondence should be addressed to Shahab D. Mohaghegh; [email protected] Received 22 August 2012; Revised 18 November 2012; Accepted 22 November 2012 Academic Editor: Serhat Akin Copyright © 2013 Qin He et al. is is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. CO 2 sequestration into a coal seam project was studied and a numerical model was developed in this paper to simulate the primary and secondary coal bed methane production (CBM/ECBM) and carbon dioxide (CO 2 ) injection. e key geological and reservoir parameters, which are germane to driving enhanced coal bed methane (ECBM) and CO 2 sequestration processes, including cleat permeability, cleat porosity, CH 4 adsorption time, CO 2 adsorption time, CH 4 Langmuir isotherm, CO 2 Langmuir isotherm, and Palmer and Mansoori parameters, have been analyzed within a reasonable range. e model simulation results showed good matches for both CBM/ECBM production and CO 2 injection compared with the �eld data. e history-matched model was used to estimate the total CO 2 sequestration capacity in the �eld. e model forecast showed that the total CO 2 injection capacity in the coal seam could be 22,817 tons, which is in agreement with the initial estimations based on the Langmuir isotherm experiment. Total CO 2 injected in the �rst three years was 2,600 tons, which according to the model has increased methane recovery (due to ECBM) by 6,700 scf/d. 1. Introduction Fossil fuels are currently playing a signi�cant role in the whole world’s energy supply. However, its damage to the environ- ment, especially the CO 2 emission resulting in the green house effect, has gotten more and more attention. At present, several geological CO 2 sequestration technologies, such as CO 2 injection into saline aquifer, CO 2 -EOR, CO 2 -ECBM, and so forth, have been studied to minimize the CO 2 release into the atmosphere, and these projects have been operating all over the world [1–6]. Studies have shown that unmineable coal seams (seams too deep or too thin to be mined economi- cally) are pretty attractive as one of the promising options for CO 2 sequestration because of their large CO 2 sequestration capacity, long time CO 2 trapping, and extra enhanced coal- bed methane (ECBM) production bene�ts [1, 7–10]. Field experience with CO 2 injection into coal seam is limited, although �eld tests are planned or are being conducted in the USA, Canada, Poland, Australia, and Japan [3]. However, unlike conventional reservoirs, gas �ow in the coal seams can cause the cleat permeability and porosity variation during the injection/production process. Once gas is injected and adsorbed on the coal matrix, the matrix will swell, and correspondently decrease the cleat permeability and porosity [11, 12]. Due to its special features and the nature of gas retention in CBM reservoirs, simulating the pro- duction and injection will have more complexity compared to conventional resources. Similar to conventional naturally fractured reservoirs, coal is characterized as a dual-porosity system consisting of matrix and cleat, in which majority of the gas is stored within the coal matrix by a process of adsorption and a small amount of free gas exists in the cleats or fractures [13]. Once CO 2 is injected into the coal seam, it will be held by coal surface because of its higher affinity to the coal matrix than methane, and then displaces the methane to boost extra natural gas production. Figure 1 shows a schematic representation of the CO 2 sequestration-ECBM process. It is estimated by
Transcript of 3 FTFBSDI SUJDMF *OKFDUJPOBOE ...downloads.hindawi.com/journals/jpe/2013/803706.pdfDPBM 7BMVFT NBZ...
Hindawi Publishing CorporationJournal of Petroleum EngineeringVolume 2013 Article ID 803706 8 pageshttpdxdoiorg1011552013803706
Research ArticleA Field Study on Simulation of CO2 Injection andECBMProduction and Prediction of CO2 Storage Capacity inUnmineable Coal Seam
QinHe Shahab D Mohaghegh and Vida Gholami
Department of Petroleum and Natural Gas Engineering West Virginia University Morgantown WV 26505 USA
Correspondence should be addressed to Shahab D Mohaghegh shahabmohagheghmailwvuedu
Received 22 August 2012 Revised 18 November 2012 Accepted 22 November 2012
Academic Editor Serhat Akin
Copyright copy 2013 Qin He et al is is an open access article distributed under the Creative Commons Attribution License whichpermits unrestricted use distribution and reproduction in any medium provided the original work is properly cited
CO2 sequestration into a coal seam project was studied and a numerical model was developed in this paper to simulate the primaryand secondary coal bed methane production (CBMECBM) and carbon dioxide (CO2) injection e key geological and reservoirparameters which are germane to driving enhanced coal bed methane (ECBM) and CO2 sequestration processes including cleatpermeability cleat porosity CH4 adsorption time CO2 adsorption time CH4 Langmuir isotherm CO2 Langmuir isotherm andPalmer and Mansoori parameters have been analyzed within a reasonable range e model simulation results showed goodmatches for both CBMECBM production and CO2 injection compared with the eld data e history-matched model was usedto estimate the total CO2 sequestration capacity in the elde model forecast showed that the total CO2 injection capacity in thecoal seam could be 22817 tons which is in agreement with the initial estimations based on the Langmuir isotherm experimentTotal CO2 injected in the rst three years was 2600 tons which according to the model has increased methane recovery (due toECBM) by 6700 scfd
1 Introduction
Fossil fuels are currently playing a signicant role in thewholeworldrsquos energy supply However its damage to the environ-ment especially the CO2 emission resulting in the greenhouse effect has gotten more and more attention At presentseveral geological CO2 sequestration technologies such asCO2 injection into saline aquifer CO2-EOR CO2-ECBMand so forth have been studied to minimize the CO2 releaseinto the atmosphere and these projects have been operatingall over the world [1ndash6] Studies have shown that unmineablecoal seams (seams too deep or too thin to bemined economi-cally) are pretty attractive as one of the promising options forCO2 sequestration because of their large CO2 sequestrationcapacity long time CO2 trapping and extra enhanced coal-bed methane (ECBM) production benets [1 7ndash10] Fieldexperience with CO2 injection into coal seam is limitedalthough eld tests are planned or are being conducted in theUSA Canada Poland Australia and Japan [3]
However unlike conventional reservoirs gas ow in thecoal seams can cause the cleat permeability and porosityvariation during the injectionproduction process Once gasis injected and adsorbed on the coal matrix the matrix willswell and correspondently decrease the cleat permeabilityand porosity [11 12] Due to its special features and thenature of gas retention inCBMreservoirs simulating the pro-duction and injectionwill havemore complexity compared toconventional resources
Similar to conventional naturally fractured reservoirscoal is characterized as a dual-porosity system consisting ofmatrix and cleat in which majority of the gas is stored withinthe coalmatrix by a process of adsorption and a small amountof free gas exists in the cleats or fractures [13] Once CO2is injected into the coal seam it will be held by coal surfacebecause of its higher affinity to the coal matrix thanmethaneand then displaces the methane to boost extra natural gasproduction Figure 1 shows a schematic representation ofthe CO2 sequestration-ECBM process It is estimated by
2 Journal of Petroleum Engineering
Cleats where free gas exists
Pores in matrix where gasadsorbs
Zoom inCO2 injection-ECBM process
CH4 is replaced by injected CO2
and desorbed from coal matrix
CO2 is injected and adsorbed incoal matrix
F 1 A schematic representation of CO2 sequestration-ECBM production
VL
PL
Gas
co
nte
ntV
(P)
Pressure
1
2VL
Langmuir isotherm
F 2 Langmuir isotherm function
laboratory measurements that this process known as CO2-enhanced coal bed methane can store twice as much CO2 asthe methane desorbed or even more [14]
e entire gas ow mechanism can be summarized inthree steps (1) desorption once free gas or water is producedfrom fracture systems in coal seams pressure starts tobe released then the adsorbed gas will be desorbed fromthe matrix surface which can be described by Langmuirisotherm equation (2) diffusion due to the gas molecularconcentration difference gas will diffuse frommatrix surfaceto cleatsmicro-pores (3) Darcys ow gas in the cleats andnatural fractureswill ow to thewellbore byDarcys ow [15]Recently the numerical reservoir simulator have become themost popular tool to predict coal seam performance andprovides a good understanding of gas ow from the reservoirto the wellbore [16]
11 Langmuir Isotherm e gas adsorptiondesorption pro-cess can be described by the typical formulation of Langmuirisotherm
119881119881(119875119875) =119881119881119871119871119875119875119875119875119871119871 + 119875119875
(1)
As shown in Figure 2 Langmuir volume (119881119881119871119871) is themaximum amount of gas that can be adsorbed on a pieceof coal at innite pressure Langmuir pressure (119875119875119871119871) is thepressure at which the Langmuir volume can be adsorbed119881119881(119875119875) is the amount of gas at different pressure also knownas gas content (scfton)Whenever the Langmuir volume andLangmuir pressure are known the adsorbed gas amount canbe calculated at any pressure
12 Diffusion Diffusion is the fact that particles movespread from high concentration to low concentration regionDiffusion of gas out of the coal matrix can be expressed bya simple diffusion equation e diffusion process in coalseams can be described by either diffusion coefficient or coaldesorption time input in the simulator [16]
120597120597120597120597120597120597120597120597
=112059112059110077141007714120597120597 119862 120597120597 100765010076501198751198751198911198911007666100766610076661007666 (2)
13 Coal Shrinkage and Swelling One of the unique charac-teristics of coal seam is the phenomenon of pressure depen-dent permeability As the production from the reservoir takesplaces two distinct phenomena occur First the reservoirpressure declines which causes the pressure in the fracturesto decline as well which in turn leads to an increase in theeffective stress within the cleats causing the cleats to be morecompactable so the cleat permeability will decrease At thesame time the gas that has been desorbed is coming out ofthe matrix which causes the matrix to shrink and the cleatsto open-up thereby the cleat permeability will be increasedAs a function of the pressure drop compressibility dominatesin early time and shrinkage dominates in the late time [16]Palmer and Mansoori model [17] is used to simulate thepermeability change process during productioninjection inthis model
emptyempty0
= 1+120597120597119891119891 100765310076531198751198751198621198751198750empty0
10076691007669+120576120576propempty0
10076521007652119870119870119872119872
11986211007668100766810076531007653119875119875
119875119875 + 119875119875119871119871119862
11987511987501198751198750 + 119875119875119871119871
10076691007669
1198701198701198701198700
= 10076531007653emptyempty0
100766910076693
(3)
2 Project Description
From 2009 the CO2 sequestration with ECBM productionproject began in Marshall County West Virginia e objec-tive of this project was to help mitigate climate change byproviding an effective and economic way to permanentlystore CO2 in un-minable coal seams In advance of CO2injection four horizontal coalbed methane wells (MH5MH11 MH18 and MH20) were drilled into the un-minableUpper Freeport coal seam which are 1200 to 1800 feetbelow the ground ese wells have been producing coalbedmethane since 2004 e center located wells (MH18 andMH20) have been converted to CO2 injection wells since
Journal of Petroleum Engineering 3
T 1 Initial reservoir parameters used in the model
Input parameters Value Unit Input parameters Value UnitAverage reservoir depth 1200 Poisson ratio 03Average formation thickness 4 Youngrsquos Modulus 125000 psiaFracture spacing IJK 002 CO2 Strain 00065Perm I-Matrix 001 md CH4 Strain 00045Perm J-Matrix 001 md PalmerMansoori exponent 3Perm K-Matrix 0001 md CO2 Langmuir Pressure 240 psiaPerm I-Fracture 02 md CO2 Langmuir Volume 890 scftonPerm J-Fracture 02 md CH4 Langmuir Pressure 402 psiaPerm K-Fracture 002 md CH4 Langmuir Volume 452 scftonPorosity-Matrix 0004 CO2 Sorption time 100 daysPorosity-Fracture 0001 CH4 Sorption time 100 daysRock compressibility-Matrix 100119864119864 119864 0119864 1psi Rock compressibility-Fracture 100119864119864 119864 0119864 1psi
September 2009 [18] 20000 short tons are planned to beinjected through well MH18 and MH20 in two years
Several questions come with this project and need tobe investigated how much CO2 can be stored in this coalseam How long does the injection process take Whichparameters affect the injection and production the mostese questions could be answered by an effective coal seammodel which was represented by a dual-porosity system toshow the uid ow through both matrix and cleat under theparticular conditions in this site e following assumptionswere considered for the modeling and simulation purpose
(1) e initial seam pressure is hydrostatic pressurewhich is 028 psi aer water is produced
(2) e ow in the coal seam is single phase includingonly CH4 and CO2
(3) e uid ow in the cleat system is a laminar ow dueto the larger pore size and it is governed by DarcyrsquosLaw while the ow in the matrix is a diffusional owdue to smaller pore size and governed by Fickrsquos Law
(4) Palmer and Mansoori equation is used to allow thenatural permeability and porosity to vary as a func-tion of pressure
In most cases the actual in situ seam data is unavailablewhich leads to the requirements of some assumptions oncertain parameters such as in this case matrixcleat per-meability matrixcleat porosity geo-mechanical properties(Youngrsquos modulus Poisson ratio) and so forth Table 1summarizes the initial physical parameters in the model
3 History-Matching Results and Discussion
As indicated before the CO2 sequestration-ECBM produc-tion project went through three stages primary methane(CBM) recovery CO2 injection and secondary methane(ECBM) recovery MH18 and MH20 were rstly performedas production wells from January 2005 to July 2007 witha following two-year shut in period thereaer they weretransferred into CO2 injection wells since September 2009MH5 and MH11 keep on methane production from the all
the way from beginning to present All well productions andinjection were simulated starting from the start day until thedate the most updated data have been recorded and reported(August 2012 in this paper)
However different performance of MH18 and MH20 indifferent time periods introduced a lot of complexity on thehistorymatching process A key factor should be respected inthe history matching either for initial methane productionor the following CO2 injection well properties (MH18 orMH20) must stay the same in the model thereby what waschanged is only the operation type
e results of sensitivity analysis were very valuablein back and forth model parameter adjustment Sensitiv-ity analysis is known as the study of how the variation(uncertainty) in the output of a mathematical model canbe apportioned qualitatively or quantitatively affected bythe change of different variations in the input of the model[19] Sensitivity analysis of coalmodeling properties is widelystudied and is addressed that it will be an important toolin future decision making [19ndash21] In this case relatedcoal parameters including cleat permeability porosity CH4desorption time CO2 desorption time CH4 Langmuir vol-ume CO2 Langmuir volume and Palmer and Mansooriparameters have been tested in themodele comparison ofcoal physical property inuences can be concluded based onthe study result as Youngrsquos modulus and Poisson ratio havelittle effect while sorption time cleat permeability strainand Langmuir isotherm are the key parameters that affectCH4 production and CO2 injection most
e actual in-seamdata for bothmethane production andCO2 injection in Upper Freeport coal seam were reporteddaily as shown in Figure 3 e average minimum bottomhole pressure in production wells is 20 psia and the averagemaximum BHP in injection wells is 900 psia e dailyinjection rate is set as constrainte trend could be observedin the production the methane production rate has clearlyincreased in MH5 and MH11 aer July 2009 due to the CO2injection A gradual decline trend in injection rate can benoticed in the injection wells especially in MH18 whichcan be a consequence of the permeability changes occurringduring desorptionadsorption process on coal
4 Journal of Petroleum Engineering
0
100
Date
Production rate
908070605040302010
0
Gas
rat
e (s
cfd
ay)
12
10
8
6
4
2
times103times103
11
42
00
4
52
82
00
5
10
10
20
06
22
22
00
8
76
20
09
11
18
20
10
41
20
12
81
42
01
3
MH11
MH5
(a)
MH20
MH18
Date
Production rate
81
20
04
21
72
00
5
95
20
05
32
42
00
6
10
10
20
06
42
82
00
7
11
14
20
07
Gas
rat
e (c
fd)
80
70
60
50
40
30
20
10
0
160
140
120
100
80
60
40
20
0
times103times103
(b)
Date
Injection rate
Gas
rat
e (s
cfd
ay)
300
250
200
150
100
50
0
140
120
100
80
60
40
20
0
MH18 injMH20 inj
76
20
09
12
22
01
0
81
02
01
0
22
62
01
1
91
42
01
1
41
20
12
10
18
20
12
times103times103
(c)
F 3 Actual CH4 production rateCO2 injection rate in Upper Freeport coal seam (a) CH4 production rate inMH11 andMH5 (b) CH4production rate in MH18 and MH20 (c) CO2 injection rate in MH18_inj and MH20_inj (MH18 and MH20 aer conversion to Injectionwells)
No regular tracking pattern of daily rate was observedbecause of frequent shut-in operations due to weather equip-ment damage or other unpredictable reasons during theinjection process erefore cumulative rates are consideredto be the history matching target by setting bottom holepressure as constraints in the model History matching wasperformed for si wells and nal eisting reservoir prop-erties including permeability porosity Langmuir isothermparameter sorption time and so forth as appropriatewere determined by history matching e history matchingresults are illustrated in Figures 4 and 5 and the coalparameters are listed in Table 2 It is important to note thatthe degree of component isotherm and sorption time at anygiven in-situ condition is directly related to the rank of thecoal Values may change in a large range from different coalseams
Figure 4 shows the fairly good history matching result ofCH4 cumulative production for all production wells Greenline and red line represents the simulated result and actualdata respectively As shown in Figure 4(a) well5 was shut
in from July 2007 to April 2009 and October 2010 to March2011 which can be seen from two short straight lines in redcumulative curves 7 times 106 3 CH4 could be produced fromwell5 by August 2012 with a stable increase As illustratedin Figure 4(b) well11 had a short shut-in period of threemonths that is why no production increase is shown inOctober 2005 and from July 2008 to November 2008 Totally2 times 107 3 CH4 were produced from well11 by August 2012a sharp build-up could be observed aer the start of largeCO2 injection on September 2009 which is because of ECBMproduction Figures 4(c) and 4(d) show the cumulative CH4production of well18 and well20 from January 2005 to July2007 respectively before they were shut-in and transferred toCO2 injection well MH18 produced 16 times 107 3 CH4 whileMH20 had a total of 1 times 107 3 CH4 production at the end ofproduction period
Figure 5 shows cumulative CO2 injection history match-ing in MH18 andMH20 aer they were converted into injec-tion wells Red dashed line represents actual CO2 injection
Journal of Petroleum Engineering 5
Date
Simulated result
Actual result
Well5
52
82
00
5
10
10
20
06
22
22
00
8
76
20
09
11
18
20
10
41
20
12
81
42
01
3
3E+07
25E+07
2E+07
15E+07
1E+07
5E+06
0E+00
Cu
mu
lati
ve g
as r
ate
(ft3
)
(a)
11
42
00
4
52
82
00
5
10
10
20
06
22
22
00
8
76
20
09
11
18
20
10
41
20
12
81
42
01
3
Well11
Date
Simulated result
Actual result
3E+07
25E+07
2E+07
15E+07
1E+07
5E+06
0E+00
Cu
mu
lati
ve g
as r
ate
(ft3
)
(b)
Simulated result
Actual result
Well18
81
20
04
21
72
00
5
95
20
05
32
42
00
6
10
10
20
06
42
82
00
7
11
14
20
07
Date
3E+07
25E+07
2E+07
15E+07
1E+07
5E+06
0E+00
Cu
mu
lati
ve g
as r
ate
(ft3
)
(c)
Simulated result
Actual result
Date
81
20
04
21
72
00
5
95
20
05
32
42
00
6
10
10
20
06
42
82
00
7
11
14
20
07
Well203E+07
25E+07
2E+07
15E+07
1E+07
5E+06
0E+00
Cu
mu
lati
ve g
as r
ate
(ft3
)
(d)
F 4 CH4 cumulative production history matching (a) CH4 cumulative production in MH5 (b) CH4 cumulative production in MH11(c) CH4 cumulative production in MH18 (d) CH4 cumulative production in MH20
data from September 2009 to August 2012 while green lineshows simulation results for both wells Certain plateauscould be seen in the curves during the whole injectionperiods which is because of the shut-in times resultingfrom operational reasons such as weather affects equipmentdamage and so forth More CO2 was injected through well18(maximum amount of 25 times 107 3 CO2) compared to 25 times107 3 CO2 injection in well20 e total amount of injectedCO2 through MH18 and MH20 has been almost 3000 tonsin the rst three years with an average ECM increase of anapproximation of 6700 scfday
4 CO2 Sequestration Capacity in Coal Seam
ere are four main CO2 storage mechanisms in coal seams(a) stratigraphic and structural trapping (b) hydrodynamictrapping (c) mineral trapping and (d) adsorption trappingIn un-mineable coal seams adsorption trapping is the mainsequestration method is is the process of accumulation ofinjected gases which is adsorbed on the surface ofmicropores
within the coal matrix e adsorption capacity will mostlydepend upon Langmuir isotherm factors [22] Figure 6illustrates the nal Langmuir Isotherm in pper Freeportcoal seam in this case
Two assumptions have beenmade in order to simplify thecalculation here
(1) No water production data was reported in this casethe coal reservoir was simulated with single phaseproduction with only CH4 and CO2
(2) Adsorption trapping is the main sequestrationmethod in un-mineable coal seam which wasconsidered as the only storage mechanism withoutincluding free gas in the fractures in this study
e CO2 adsorption capacity in the coal seam can becalculated as
OGIP = 119860119860 times 119860 times 119860119860119887119887 times 119866119866ci = 119881119881 times 119860119860119887119887 times 119866119866ci (4)
where 119881119881119871119871 = 800 scfton 119875119875119871119871 = 412 psia 119875119875 = 028 psi times1200 = 360 psi and 119881119881119881119875119875119881 = 119866119866ci = 119881119881119871119871119875119875119875119881119875119875119871119871 + 119875119875119881 = 800 times
6 Journal of Petroleum Engineering
T 2 History matched reservoir parameter setting
Input parameters Value Unit Input parameters Value UnitAverage reservoir depth 1200 Poisson ratio 03Average formation thickness 4 Youngrsquos Modulus 125000 psiaFracture spacing IJK 0015 CO2 Strain 00025Perm I-Matrix 001ndash002 md CH4 Strain 00045Perm J-Matrix 001ndash002 md PalmerMansoori exponent 3Perm K-Matrix 0001ndash0002 md CO2 Langmuir Pressure 412 psiaPerm I-Fracture 02ndash04 md CO2 Langmuir Volume 800 scftonPerm J-Fracture 02ndash04 md CH4 Langmuir Pressure 628 psiaPerm K-Fracture 002ndash004 md CH4 Langmuir Volume 652 scftonPorosity-Matrix 0002ndash0004 CO2 Sorption time 140 daysPorosity-Fracture 0001ndash0002 CH4 Sorption time 350 daysRock compressibility-Matrix 100119864119864 119864 0119864 1psi Rock compressibility-Fracture 100119864119864 119864 0119864 1psi
Simulated result
Actual result
76
20
09
12
22
01
0
81
02
01
0
22
62
01
1
91
42
01
1
41
20
12
10
18
20
12
Date
Well18 inj
3E+07
25E+07
2E+07
15E+07
1E+07
5E+06
0E+00
Cu
mu
lati
ve g
as r
ate
(ft3
)
(a)
Simulated result
Actual result
76
20
09
12
22
01
0
81
02
01
0
22
62
01
1
91
42
01
1
41
20
12
10
18
20
12
Well20 inj
Date
3E+07
25E+07
2E+07
15E+07
1E+07
5E+06
0E+00
Cu
mu
lati
ve g
as r
ate
(ft3
)
(b)
F 5 Cumulative CO2 injection history matching (a) Cumulative CO2 injection in MH18_inj (b) Cumulative CO2 injection inMH20_inj
Journal of Petroleum Engineering 7
0
100
200
300
400
500
600
700
800
900
0 5000 10000 15000 20000 25000 30000 35000 40000
Langmuir isotherm
Gas
co
nte
nt
(scf
to
n)
Pressure (psia)
CO2
CH4
F 6 Existing Langmuir isotherm for CO2 and CH4 in UpperFreeport Coal seam
360(412 + 360) = 373 scfton where 120588120588119887119887 = 85 lbs3 119881119881 =25193558 3 1 ton = 2000 lbs Coal tonnage = 85 times251935582000 = 1069466 tons OGIP = 1069466 tons times373 scfton17483 tonscf = 22817 tons (coal seam volumeand coal density were provided and were used directly)
5 Summary and Conclusions
e modeling and history matching process of methaneproduction and ECBM as well as CO2 injection in a coal bedseamwas explained in this workis process was performedusing conducting actual data analysis and sensitivity analysisof related coal seam physical properties on four horizontalwells drilled in Upper Freeport coal seam Results of historymatching were compiled to show the initial and existingcondition in the coal seam CO2 sequestration capacity pre-diction was completed according to the Langmuir isothermproperties obtained from the history matched reservoirmodel
e simulation of CH4 gasication and CO2 injectionprocess was quite complicated e special swelling andshrinkage features and the nature of gas retention in CBMreservoirs make the modeling and history matching of pro-duction and injectiondata in coal bedmethanemore complexbecause of the permeability and porosity variations comparedto conventional resources
Sensitivity analysis results suggested that sorption timecleat permeability strain and Langmuir isotherm are themost inuential parameters during CH4 production andCO2injection process It is concluded by the Langmuir isothermparameters from history matched model that the total CO2sequestration capacity is about 22817 tons excluding the freegas part in the cleat system e total CO2 injection amountin the rst three years was 45 times 107 3 or 2600 tons whichcaused an increase of 6700 scfday in CH4 production ratefrom other two wells
Nomenclature
119863119863 Diffusion coefficient119862119862 Average gas concentration in the matrix120591120591 Desorption time days119862119862119891119891((1198751198751198751198751198750)empty0) Stress-dependent permeability term(1198701198701198701198701198751)(119875119875(119875119875+119875119875120576120576)1198751198751198750(1198751198750+119875119875120576120576)(1198701198701198701198701198751)(119875119875(119875119875+119875119875120576120576) 119875 (1198751198750(1198751198750 + 119875119875120576120576)))) Matrix shrinkage termΦ119894119894 Initial fracture porosity 119862119862119891119891 Pore volume compressibility 1psi119875119875 Initial pressure psi119870119870 Axial modulus psi119870119870 Bulk modulus psi120576120576 Langmuir strain119875119875119871119871 Langmuir pressure psi119881119881119871119871 Langmuir volume scfton
119860119860 Drainage area 2
ℎ Net pay
120588120588119887119887 Bulk density lbs3
119866119866ci Gas Content scftonempty119894119894 Porosity119861119861gi Initial formation volume factor STBscfOGIP Original gas in place tons
119881119881 Coal volume 3
Acknowledgments
is project was funded by the Department of EnergyNational Energy Technology Laboratory Consol Energythrough a support contract with URS Energy and Construc-tion Inc e authors want to acknowledge the importantcontributions of Consol Energy for the eld data available foranalysis Acknowledgment is also extended to TomWilson inWVU for providing the geological maps for the studied eldin this researchanks go toComputerModelingGroupLtd(CMG) for providing the soware to do the PEARL researchgroup at WVU
References
[1] S H Stevens D Spector and P Riemer ldquoEnhanced coalbedmethane recovery using CO2 injection worldwide resourceand CO2 sequestration potentialrdquo in Proceedings of the 6thInternational Oil amp Gas Conference and Exhibition in China(IOGCEC rsquo98) pp 489ndash501 Beijing China November 1998
[2] J Ennis-King and L Paterson ldquoEngineering aspects of geo-logical sequestration of carbon dioxiderdquo in Proceedings of thePE sia Pacic Oil and Gas Conference and Exhibition pp134ndash146 Melbourne Australia October 2002
[3] FM Orr Jr ldquoStorage of carbon dioxide in geologic formationsrdquoJournal of Petroleum Technology vol 56 no 9 pp 90ndash97 2004
8 Journal of Petroleum Engineering
[4] C Sinayuccedil and F Guumlmrah ldquoModeling of ECBM recovery fromamasra coalbed in Zonguldak Basin Turkeyrdquo in Proceedingsof the Canadian International Petroleum Conference AlbertaCanada 2008
[5] R Petrusak D Riestenberg P Goad et al ldquoWorld class CO2sequestration potential in saline formations oil and gas eldscoal and shale the US southeast regional carbon sequestrationpartnership has it allrdquo in Proceedings of the SPE InternationalConference on CO2 Capture Storage and Utilization pp136ndash153 November 2009
[6] C L Liner ldquoCarbon capture and sequestration overview andoffshore aspectsrdquo in Proceedings of the Offshore TechnologyConference (OTC rsquo10) pp 3511ndash3514 May 2010
[7] J P Seidle ldquoReservoir engineering aspects of CO2 sequestrationin coalsrdquo in Proceedings of the SPECERI Gas TechnologySymposium Alberta Canada 2000
[8] H J M Pagnier F Van Bergen E Kre L G H VanDer Meer and H J Simmelink ldquoField experiment of ECBM-CO2 in the upper Silesian Basin of Poland (RECOPOL)rdquo inProceedings of the 67th European Association of Geoscientistsand Engineers EAGE Conference and Exhibition incorporatingSPE (EUROPEC rsquo05) pp 3013ndash3015 Madrid Spain June 2005
[9] G A Hernandez R O Bello D A McVay et al ldquoEvaluation ofthe technical and economic feasibility of CO2 sequestration andenhanced coalbed-methane recovery in Texas low-rank coalsrdquoin Proceedings of the SPE Gas Technology Symposium MatureFields to New Frontiers pp 515ndash530 Alberta Canada May2006
[10] G J Koperna and D Riestenberg ldquoCarbon dioxide enhancedcoalbed methane and storage is there promiserdquo in Proceedingsof the SPE International Conference on CO2 Capture Storageand Utilization pp 183ndash195 November 2009
[11] J Q Shi and S Durucan ldquoA model for changes in coalbedpermeability during primary and enhanced methane recoveryrdquoSPE Reservoir Evaluation and Engineering vol 8 no 4 pp291ndash299 2005
[12] S Mazumder and K H Wolf ldquoDifferential swelling andpermeability change of coal in response to CO2 injection forECBMrdquo International Journal of Coal Geology vol 74 no 2 pp123ndash138 2008
[13] L Dean ldquoReservoir engineering for geologists coalbed meth-ane fundamentalsrdquo Reservoir Issue 2007 11
[14] Storing CO2 in Unminable Coal Seams IEA Greenhouse GasRampD Programme
[15] K Aminian and S Ameri ldquoPredicting production performanceof CBM reservoirsrdquo Journal of Natural Gas Science and Engi-neering vol 1 no 1-2 pp 25ndash30 2009
[16] I Zulkamain Simulation study of the effect of well spacingpermeability anisotropy Palmar andMansoori model on coalbedmethane production [MS thesis] Texas AampMUniversity 2005
[17] I Palmer and JMansoori ldquoHowpermeability depends on stressand pore pressure in coalbeds a new modelrdquo SPE ReservoirEngineering vol 1 no 6 pp 539ndash543 1998
[18] ldquoCO2 storage with ECBM studybegins in West VirginiardquohttpwwwcarboncapturejournalcomdisplaynewsphpNewsID=442
[19] D J Remner T Ertekin W Sung and G R King ldquoParametricstudy of the effects of coal seam properties on gas drainageefficiencyrdquo SPE Reservoir Engineering vol 1 no 6 pp 633ndash6461986
[20] A N Okeke Sensitivity analysis of modeling parameters thataffect the dual peaking behavior in coalbed methane reservoirs[MS thesis] Texas AampM University 2005
[21] Q P Huy K Sasaki Y Sugai et al ldquoNumerical simulation ofCO2 enhanced coal bed methane recovery for A vietmese coalseamrdquo JournaL of NoveL Carbon Resource Sciences vol 2 pp1ndash7 2010
[22] D Jasinge and P G Ranjith ldquoCarbon dioxide sequestrationin geologic formation with special reference to sequestrationin deep coal seamsrdquo in Proceedings of the 45th US RockMechanicsGeomechanics Symposium 2011
International Journal of
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Shock and Vibration
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Electrical and Computer Engineering
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Modelling amp Simulation in EngineeringHindawi Publishing Corporation httpwwwhindawicom Volume 2014
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Chemical EngineeringInternational Journal of Antennas and
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DistributedSensor Networks
International Journal of
2 Journal of Petroleum Engineering
Cleats where free gas exists
Pores in matrix where gasadsorbs
Zoom inCO2 injection-ECBM process
CH4 is replaced by injected CO2
and desorbed from coal matrix
CO2 is injected and adsorbed incoal matrix
F 1 A schematic representation of CO2 sequestration-ECBM production
VL
PL
Gas
co
nte
ntV
(P)
Pressure
1
2VL
Langmuir isotherm
F 2 Langmuir isotherm function
laboratory measurements that this process known as CO2-enhanced coal bed methane can store twice as much CO2 asthe methane desorbed or even more [14]
e entire gas ow mechanism can be summarized inthree steps (1) desorption once free gas or water is producedfrom fracture systems in coal seams pressure starts tobe released then the adsorbed gas will be desorbed fromthe matrix surface which can be described by Langmuirisotherm equation (2) diffusion due to the gas molecularconcentration difference gas will diffuse frommatrix surfaceto cleatsmicro-pores (3) Darcys ow gas in the cleats andnatural fractureswill ow to thewellbore byDarcys ow [15]Recently the numerical reservoir simulator have become themost popular tool to predict coal seam performance andprovides a good understanding of gas ow from the reservoirto the wellbore [16]
11 Langmuir Isotherm e gas adsorptiondesorption pro-cess can be described by the typical formulation of Langmuirisotherm
119881119881(119875119875) =119881119881119871119871119875119875119875119875119871119871 + 119875119875
(1)
As shown in Figure 2 Langmuir volume (119881119881119871119871) is themaximum amount of gas that can be adsorbed on a pieceof coal at innite pressure Langmuir pressure (119875119875119871119871) is thepressure at which the Langmuir volume can be adsorbed119881119881(119875119875) is the amount of gas at different pressure also knownas gas content (scfton)Whenever the Langmuir volume andLangmuir pressure are known the adsorbed gas amount canbe calculated at any pressure
12 Diffusion Diffusion is the fact that particles movespread from high concentration to low concentration regionDiffusion of gas out of the coal matrix can be expressed bya simple diffusion equation e diffusion process in coalseams can be described by either diffusion coefficient or coaldesorption time input in the simulator [16]
120597120597120597120597120597120597120597120597
=112059112059110077141007714120597120597 119862 120597120597 100765010076501198751198751198911198911007666100766610076661007666 (2)
13 Coal Shrinkage and Swelling One of the unique charac-teristics of coal seam is the phenomenon of pressure depen-dent permeability As the production from the reservoir takesplaces two distinct phenomena occur First the reservoirpressure declines which causes the pressure in the fracturesto decline as well which in turn leads to an increase in theeffective stress within the cleats causing the cleats to be morecompactable so the cleat permeability will decrease At thesame time the gas that has been desorbed is coming out ofthe matrix which causes the matrix to shrink and the cleatsto open-up thereby the cleat permeability will be increasedAs a function of the pressure drop compressibility dominatesin early time and shrinkage dominates in the late time [16]Palmer and Mansoori model [17] is used to simulate thepermeability change process during productioninjection inthis model
emptyempty0
= 1+120597120597119891119891 100765310076531198751198751198621198751198750empty0
10076691007669+120576120576propempty0
10076521007652119870119870119872119872
11986211007668100766810076531007653119875119875
119875119875 + 119875119875119871119871119862
11987511987501198751198750 + 119875119875119871119871
10076691007669
1198701198701198701198700
= 10076531007653emptyempty0
100766910076693
(3)
2 Project Description
From 2009 the CO2 sequestration with ECBM productionproject began in Marshall County West Virginia e objec-tive of this project was to help mitigate climate change byproviding an effective and economic way to permanentlystore CO2 in un-minable coal seams In advance of CO2injection four horizontal coalbed methane wells (MH5MH11 MH18 and MH20) were drilled into the un-minableUpper Freeport coal seam which are 1200 to 1800 feetbelow the ground ese wells have been producing coalbedmethane since 2004 e center located wells (MH18 andMH20) have been converted to CO2 injection wells since
Journal of Petroleum Engineering 3
T 1 Initial reservoir parameters used in the model
Input parameters Value Unit Input parameters Value UnitAverage reservoir depth 1200 Poisson ratio 03Average formation thickness 4 Youngrsquos Modulus 125000 psiaFracture spacing IJK 002 CO2 Strain 00065Perm I-Matrix 001 md CH4 Strain 00045Perm J-Matrix 001 md PalmerMansoori exponent 3Perm K-Matrix 0001 md CO2 Langmuir Pressure 240 psiaPerm I-Fracture 02 md CO2 Langmuir Volume 890 scftonPerm J-Fracture 02 md CH4 Langmuir Pressure 402 psiaPerm K-Fracture 002 md CH4 Langmuir Volume 452 scftonPorosity-Matrix 0004 CO2 Sorption time 100 daysPorosity-Fracture 0001 CH4 Sorption time 100 daysRock compressibility-Matrix 100119864119864 119864 0119864 1psi Rock compressibility-Fracture 100119864119864 119864 0119864 1psi
September 2009 [18] 20000 short tons are planned to beinjected through well MH18 and MH20 in two years
Several questions come with this project and need tobe investigated how much CO2 can be stored in this coalseam How long does the injection process take Whichparameters affect the injection and production the mostese questions could be answered by an effective coal seammodel which was represented by a dual-porosity system toshow the uid ow through both matrix and cleat under theparticular conditions in this site e following assumptionswere considered for the modeling and simulation purpose
(1) e initial seam pressure is hydrostatic pressurewhich is 028 psi aer water is produced
(2) e ow in the coal seam is single phase includingonly CH4 and CO2
(3) e uid ow in the cleat system is a laminar ow dueto the larger pore size and it is governed by DarcyrsquosLaw while the ow in the matrix is a diffusional owdue to smaller pore size and governed by Fickrsquos Law
(4) Palmer and Mansoori equation is used to allow thenatural permeability and porosity to vary as a func-tion of pressure
In most cases the actual in situ seam data is unavailablewhich leads to the requirements of some assumptions oncertain parameters such as in this case matrixcleat per-meability matrixcleat porosity geo-mechanical properties(Youngrsquos modulus Poisson ratio) and so forth Table 1summarizes the initial physical parameters in the model
3 History-Matching Results and Discussion
As indicated before the CO2 sequestration-ECBM produc-tion project went through three stages primary methane(CBM) recovery CO2 injection and secondary methane(ECBM) recovery MH18 and MH20 were rstly performedas production wells from January 2005 to July 2007 witha following two-year shut in period thereaer they weretransferred into CO2 injection wells since September 2009MH5 and MH11 keep on methane production from the all
the way from beginning to present All well productions andinjection were simulated starting from the start day until thedate the most updated data have been recorded and reported(August 2012 in this paper)
However different performance of MH18 and MH20 indifferent time periods introduced a lot of complexity on thehistorymatching process A key factor should be respected inthe history matching either for initial methane productionor the following CO2 injection well properties (MH18 orMH20) must stay the same in the model thereby what waschanged is only the operation type
e results of sensitivity analysis were very valuablein back and forth model parameter adjustment Sensitiv-ity analysis is known as the study of how the variation(uncertainty) in the output of a mathematical model canbe apportioned qualitatively or quantitatively affected bythe change of different variations in the input of the model[19] Sensitivity analysis of coalmodeling properties is widelystudied and is addressed that it will be an important toolin future decision making [19ndash21] In this case relatedcoal parameters including cleat permeability porosity CH4desorption time CO2 desorption time CH4 Langmuir vol-ume CO2 Langmuir volume and Palmer and Mansooriparameters have been tested in themodele comparison ofcoal physical property inuences can be concluded based onthe study result as Youngrsquos modulus and Poisson ratio havelittle effect while sorption time cleat permeability strainand Langmuir isotherm are the key parameters that affectCH4 production and CO2 injection most
e actual in-seamdata for bothmethane production andCO2 injection in Upper Freeport coal seam were reporteddaily as shown in Figure 3 e average minimum bottomhole pressure in production wells is 20 psia and the averagemaximum BHP in injection wells is 900 psia e dailyinjection rate is set as constrainte trend could be observedin the production the methane production rate has clearlyincreased in MH5 and MH11 aer July 2009 due to the CO2injection A gradual decline trend in injection rate can benoticed in the injection wells especially in MH18 whichcan be a consequence of the permeability changes occurringduring desorptionadsorption process on coal
4 Journal of Petroleum Engineering
0
100
Date
Production rate
908070605040302010
0
Gas
rat
e (s
cfd
ay)
12
10
8
6
4
2
times103times103
11
42
00
4
52
82
00
5
10
10
20
06
22
22
00
8
76
20
09
11
18
20
10
41
20
12
81
42
01
3
MH11
MH5
(a)
MH20
MH18
Date
Production rate
81
20
04
21
72
00
5
95
20
05
32
42
00
6
10
10
20
06
42
82
00
7
11
14
20
07
Gas
rat
e (c
fd)
80
70
60
50
40
30
20
10
0
160
140
120
100
80
60
40
20
0
times103times103
(b)
Date
Injection rate
Gas
rat
e (s
cfd
ay)
300
250
200
150
100
50
0
140
120
100
80
60
40
20
0
MH18 injMH20 inj
76
20
09
12
22
01
0
81
02
01
0
22
62
01
1
91
42
01
1
41
20
12
10
18
20
12
times103times103
(c)
F 3 Actual CH4 production rateCO2 injection rate in Upper Freeport coal seam (a) CH4 production rate inMH11 andMH5 (b) CH4production rate in MH18 and MH20 (c) CO2 injection rate in MH18_inj and MH20_inj (MH18 and MH20 aer conversion to Injectionwells)
No regular tracking pattern of daily rate was observedbecause of frequent shut-in operations due to weather equip-ment damage or other unpredictable reasons during theinjection process erefore cumulative rates are consideredto be the history matching target by setting bottom holepressure as constraints in the model History matching wasperformed for si wells and nal eisting reservoir prop-erties including permeability porosity Langmuir isothermparameter sorption time and so forth as appropriatewere determined by history matching e history matchingresults are illustrated in Figures 4 and 5 and the coalparameters are listed in Table 2 It is important to note thatthe degree of component isotherm and sorption time at anygiven in-situ condition is directly related to the rank of thecoal Values may change in a large range from different coalseams
Figure 4 shows the fairly good history matching result ofCH4 cumulative production for all production wells Greenline and red line represents the simulated result and actualdata respectively As shown in Figure 4(a) well5 was shut
in from July 2007 to April 2009 and October 2010 to March2011 which can be seen from two short straight lines in redcumulative curves 7 times 106 3 CH4 could be produced fromwell5 by August 2012 with a stable increase As illustratedin Figure 4(b) well11 had a short shut-in period of threemonths that is why no production increase is shown inOctober 2005 and from July 2008 to November 2008 Totally2 times 107 3 CH4 were produced from well11 by August 2012a sharp build-up could be observed aer the start of largeCO2 injection on September 2009 which is because of ECBMproduction Figures 4(c) and 4(d) show the cumulative CH4production of well18 and well20 from January 2005 to July2007 respectively before they were shut-in and transferred toCO2 injection well MH18 produced 16 times 107 3 CH4 whileMH20 had a total of 1 times 107 3 CH4 production at the end ofproduction period
Figure 5 shows cumulative CO2 injection history match-ing in MH18 andMH20 aer they were converted into injec-tion wells Red dashed line represents actual CO2 injection
Journal of Petroleum Engineering 5
Date
Simulated result
Actual result
Well5
52
82
00
5
10
10
20
06
22
22
00
8
76
20
09
11
18
20
10
41
20
12
81
42
01
3
3E+07
25E+07
2E+07
15E+07
1E+07
5E+06
0E+00
Cu
mu
lati
ve g
as r
ate
(ft3
)
(a)
11
42
00
4
52
82
00
5
10
10
20
06
22
22
00
8
76
20
09
11
18
20
10
41
20
12
81
42
01
3
Well11
Date
Simulated result
Actual result
3E+07
25E+07
2E+07
15E+07
1E+07
5E+06
0E+00
Cu
mu
lati
ve g
as r
ate
(ft3
)
(b)
Simulated result
Actual result
Well18
81
20
04
21
72
00
5
95
20
05
32
42
00
6
10
10
20
06
42
82
00
7
11
14
20
07
Date
3E+07
25E+07
2E+07
15E+07
1E+07
5E+06
0E+00
Cu
mu
lati
ve g
as r
ate
(ft3
)
(c)
Simulated result
Actual result
Date
81
20
04
21
72
00
5
95
20
05
32
42
00
6
10
10
20
06
42
82
00
7
11
14
20
07
Well203E+07
25E+07
2E+07
15E+07
1E+07
5E+06
0E+00
Cu
mu
lati
ve g
as r
ate
(ft3
)
(d)
F 4 CH4 cumulative production history matching (a) CH4 cumulative production in MH5 (b) CH4 cumulative production in MH11(c) CH4 cumulative production in MH18 (d) CH4 cumulative production in MH20
data from September 2009 to August 2012 while green lineshows simulation results for both wells Certain plateauscould be seen in the curves during the whole injectionperiods which is because of the shut-in times resultingfrom operational reasons such as weather affects equipmentdamage and so forth More CO2 was injected through well18(maximum amount of 25 times 107 3 CO2) compared to 25 times107 3 CO2 injection in well20 e total amount of injectedCO2 through MH18 and MH20 has been almost 3000 tonsin the rst three years with an average ECM increase of anapproximation of 6700 scfday
4 CO2 Sequestration Capacity in Coal Seam
ere are four main CO2 storage mechanisms in coal seams(a) stratigraphic and structural trapping (b) hydrodynamictrapping (c) mineral trapping and (d) adsorption trappingIn un-mineable coal seams adsorption trapping is the mainsequestration method is is the process of accumulation ofinjected gases which is adsorbed on the surface ofmicropores
within the coal matrix e adsorption capacity will mostlydepend upon Langmuir isotherm factors [22] Figure 6illustrates the nal Langmuir Isotherm in pper Freeportcoal seam in this case
Two assumptions have beenmade in order to simplify thecalculation here
(1) No water production data was reported in this casethe coal reservoir was simulated with single phaseproduction with only CH4 and CO2
(2) Adsorption trapping is the main sequestrationmethod in un-mineable coal seam which wasconsidered as the only storage mechanism withoutincluding free gas in the fractures in this study
e CO2 adsorption capacity in the coal seam can becalculated as
OGIP = 119860119860 times 119860 times 119860119860119887119887 times 119866119866ci = 119881119881 times 119860119860119887119887 times 119866119866ci (4)
where 119881119881119871119871 = 800 scfton 119875119875119871119871 = 412 psia 119875119875 = 028 psi times1200 = 360 psi and 119881119881119881119875119875119881 = 119866119866ci = 119881119881119871119871119875119875119875119881119875119875119871119871 + 119875119875119881 = 800 times
6 Journal of Petroleum Engineering
T 2 History matched reservoir parameter setting
Input parameters Value Unit Input parameters Value UnitAverage reservoir depth 1200 Poisson ratio 03Average formation thickness 4 Youngrsquos Modulus 125000 psiaFracture spacing IJK 0015 CO2 Strain 00025Perm I-Matrix 001ndash002 md CH4 Strain 00045Perm J-Matrix 001ndash002 md PalmerMansoori exponent 3Perm K-Matrix 0001ndash0002 md CO2 Langmuir Pressure 412 psiaPerm I-Fracture 02ndash04 md CO2 Langmuir Volume 800 scftonPerm J-Fracture 02ndash04 md CH4 Langmuir Pressure 628 psiaPerm K-Fracture 002ndash004 md CH4 Langmuir Volume 652 scftonPorosity-Matrix 0002ndash0004 CO2 Sorption time 140 daysPorosity-Fracture 0001ndash0002 CH4 Sorption time 350 daysRock compressibility-Matrix 100119864119864 119864 0119864 1psi Rock compressibility-Fracture 100119864119864 119864 0119864 1psi
Simulated result
Actual result
76
20
09
12
22
01
0
81
02
01
0
22
62
01
1
91
42
01
1
41
20
12
10
18
20
12
Date
Well18 inj
3E+07
25E+07
2E+07
15E+07
1E+07
5E+06
0E+00
Cu
mu
lati
ve g
as r
ate
(ft3
)
(a)
Simulated result
Actual result
76
20
09
12
22
01
0
81
02
01
0
22
62
01
1
91
42
01
1
41
20
12
10
18
20
12
Well20 inj
Date
3E+07
25E+07
2E+07
15E+07
1E+07
5E+06
0E+00
Cu
mu
lati
ve g
as r
ate
(ft3
)
(b)
F 5 Cumulative CO2 injection history matching (a) Cumulative CO2 injection in MH18_inj (b) Cumulative CO2 injection inMH20_inj
Journal of Petroleum Engineering 7
0
100
200
300
400
500
600
700
800
900
0 5000 10000 15000 20000 25000 30000 35000 40000
Langmuir isotherm
Gas
co
nte
nt
(scf
to
n)
Pressure (psia)
CO2
CH4
F 6 Existing Langmuir isotherm for CO2 and CH4 in UpperFreeport Coal seam
360(412 + 360) = 373 scfton where 120588120588119887119887 = 85 lbs3 119881119881 =25193558 3 1 ton = 2000 lbs Coal tonnage = 85 times251935582000 = 1069466 tons OGIP = 1069466 tons times373 scfton17483 tonscf = 22817 tons (coal seam volumeand coal density were provided and were used directly)
5 Summary and Conclusions
e modeling and history matching process of methaneproduction and ECBM as well as CO2 injection in a coal bedseamwas explained in this workis process was performedusing conducting actual data analysis and sensitivity analysisof related coal seam physical properties on four horizontalwells drilled in Upper Freeport coal seam Results of historymatching were compiled to show the initial and existingcondition in the coal seam CO2 sequestration capacity pre-diction was completed according to the Langmuir isothermproperties obtained from the history matched reservoirmodel
e simulation of CH4 gasication and CO2 injectionprocess was quite complicated e special swelling andshrinkage features and the nature of gas retention in CBMreservoirs make the modeling and history matching of pro-duction and injectiondata in coal bedmethanemore complexbecause of the permeability and porosity variations comparedto conventional resources
Sensitivity analysis results suggested that sorption timecleat permeability strain and Langmuir isotherm are themost inuential parameters during CH4 production andCO2injection process It is concluded by the Langmuir isothermparameters from history matched model that the total CO2sequestration capacity is about 22817 tons excluding the freegas part in the cleat system e total CO2 injection amountin the rst three years was 45 times 107 3 or 2600 tons whichcaused an increase of 6700 scfday in CH4 production ratefrom other two wells
Nomenclature
119863119863 Diffusion coefficient119862119862 Average gas concentration in the matrix120591120591 Desorption time days119862119862119891119891((1198751198751198751198751198750)empty0) Stress-dependent permeability term(1198701198701198701198701198751)(119875119875(119875119875+119875119875120576120576)1198751198751198750(1198751198750+119875119875120576120576)(1198701198701198701198701198751)(119875119875(119875119875+119875119875120576120576) 119875 (1198751198750(1198751198750 + 119875119875120576120576)))) Matrix shrinkage termΦ119894119894 Initial fracture porosity 119862119862119891119891 Pore volume compressibility 1psi119875119875 Initial pressure psi119870119870 Axial modulus psi119870119870 Bulk modulus psi120576120576 Langmuir strain119875119875119871119871 Langmuir pressure psi119881119881119871119871 Langmuir volume scfton
119860119860 Drainage area 2
ℎ Net pay
120588120588119887119887 Bulk density lbs3
119866119866ci Gas Content scftonempty119894119894 Porosity119861119861gi Initial formation volume factor STBscfOGIP Original gas in place tons
119881119881 Coal volume 3
Acknowledgments
is project was funded by the Department of EnergyNational Energy Technology Laboratory Consol Energythrough a support contract with URS Energy and Construc-tion Inc e authors want to acknowledge the importantcontributions of Consol Energy for the eld data available foranalysis Acknowledgment is also extended to TomWilson inWVU for providing the geological maps for the studied eldin this researchanks go toComputerModelingGroupLtd(CMG) for providing the soware to do the PEARL researchgroup at WVU
References
[1] S H Stevens D Spector and P Riemer ldquoEnhanced coalbedmethane recovery using CO2 injection worldwide resourceand CO2 sequestration potentialrdquo in Proceedings of the 6thInternational Oil amp Gas Conference and Exhibition in China(IOGCEC rsquo98) pp 489ndash501 Beijing China November 1998
[2] J Ennis-King and L Paterson ldquoEngineering aspects of geo-logical sequestration of carbon dioxiderdquo in Proceedings of thePE sia Pacic Oil and Gas Conference and Exhibition pp134ndash146 Melbourne Australia October 2002
[3] FM Orr Jr ldquoStorage of carbon dioxide in geologic formationsrdquoJournal of Petroleum Technology vol 56 no 9 pp 90ndash97 2004
8 Journal of Petroleum Engineering
[4] C Sinayuccedil and F Guumlmrah ldquoModeling of ECBM recovery fromamasra coalbed in Zonguldak Basin Turkeyrdquo in Proceedingsof the Canadian International Petroleum Conference AlbertaCanada 2008
[5] R Petrusak D Riestenberg P Goad et al ldquoWorld class CO2sequestration potential in saline formations oil and gas eldscoal and shale the US southeast regional carbon sequestrationpartnership has it allrdquo in Proceedings of the SPE InternationalConference on CO2 Capture Storage and Utilization pp136ndash153 November 2009
[6] C L Liner ldquoCarbon capture and sequestration overview andoffshore aspectsrdquo in Proceedings of the Offshore TechnologyConference (OTC rsquo10) pp 3511ndash3514 May 2010
[7] J P Seidle ldquoReservoir engineering aspects of CO2 sequestrationin coalsrdquo in Proceedings of the SPECERI Gas TechnologySymposium Alberta Canada 2000
[8] H J M Pagnier F Van Bergen E Kre L G H VanDer Meer and H J Simmelink ldquoField experiment of ECBM-CO2 in the upper Silesian Basin of Poland (RECOPOL)rdquo inProceedings of the 67th European Association of Geoscientistsand Engineers EAGE Conference and Exhibition incorporatingSPE (EUROPEC rsquo05) pp 3013ndash3015 Madrid Spain June 2005
[9] G A Hernandez R O Bello D A McVay et al ldquoEvaluation ofthe technical and economic feasibility of CO2 sequestration andenhanced coalbed-methane recovery in Texas low-rank coalsrdquoin Proceedings of the SPE Gas Technology Symposium MatureFields to New Frontiers pp 515ndash530 Alberta Canada May2006
[10] G J Koperna and D Riestenberg ldquoCarbon dioxide enhancedcoalbed methane and storage is there promiserdquo in Proceedingsof the SPE International Conference on CO2 Capture Storageand Utilization pp 183ndash195 November 2009
[11] J Q Shi and S Durucan ldquoA model for changes in coalbedpermeability during primary and enhanced methane recoveryrdquoSPE Reservoir Evaluation and Engineering vol 8 no 4 pp291ndash299 2005
[12] S Mazumder and K H Wolf ldquoDifferential swelling andpermeability change of coal in response to CO2 injection forECBMrdquo International Journal of Coal Geology vol 74 no 2 pp123ndash138 2008
[13] L Dean ldquoReservoir engineering for geologists coalbed meth-ane fundamentalsrdquo Reservoir Issue 2007 11
[14] Storing CO2 in Unminable Coal Seams IEA Greenhouse GasRampD Programme
[15] K Aminian and S Ameri ldquoPredicting production performanceof CBM reservoirsrdquo Journal of Natural Gas Science and Engi-neering vol 1 no 1-2 pp 25ndash30 2009
[16] I Zulkamain Simulation study of the effect of well spacingpermeability anisotropy Palmar andMansoori model on coalbedmethane production [MS thesis] Texas AampMUniversity 2005
[17] I Palmer and JMansoori ldquoHowpermeability depends on stressand pore pressure in coalbeds a new modelrdquo SPE ReservoirEngineering vol 1 no 6 pp 539ndash543 1998
[18] ldquoCO2 storage with ECBM studybegins in West VirginiardquohttpwwwcarboncapturejournalcomdisplaynewsphpNewsID=442
[19] D J Remner T Ertekin W Sung and G R King ldquoParametricstudy of the effects of coal seam properties on gas drainageefficiencyrdquo SPE Reservoir Engineering vol 1 no 6 pp 633ndash6461986
[20] A N Okeke Sensitivity analysis of modeling parameters thataffect the dual peaking behavior in coalbed methane reservoirs[MS thesis] Texas AampM University 2005
[21] Q P Huy K Sasaki Y Sugai et al ldquoNumerical simulation ofCO2 enhanced coal bed methane recovery for A vietmese coalseamrdquo JournaL of NoveL Carbon Resource Sciences vol 2 pp1ndash7 2010
[22] D Jasinge and P G Ranjith ldquoCarbon dioxide sequestrationin geologic formation with special reference to sequestrationin deep coal seamsrdquo in Proceedings of the 45th US RockMechanicsGeomechanics Symposium 2011
International Journal of
AerospaceEngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
RoboticsJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Active and Passive Electronic Components
Control Scienceand Engineering
Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
International Journal of
RotatingMachinery
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporation httpwwwhindawicom
Journal ofEngineeringVolume 2014
Submit your manuscripts athttpwwwhindawicom
VLSI Design
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Shock and Vibration
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Civil EngineeringAdvances in
Acoustics and VibrationAdvances in
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Electrical and Computer Engineering
Journal of
Advances inOptoElectronics
Hindawi Publishing Corporation httpwwwhindawicom
Volume 2014
The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
SensorsJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Modelling amp Simulation in EngineeringHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Chemical EngineeringInternational Journal of Antennas and
Propagation
International Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Navigation and Observation
International Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
DistributedSensor Networks
International Journal of
Journal of Petroleum Engineering 3
T 1 Initial reservoir parameters used in the model
Input parameters Value Unit Input parameters Value UnitAverage reservoir depth 1200 Poisson ratio 03Average formation thickness 4 Youngrsquos Modulus 125000 psiaFracture spacing IJK 002 CO2 Strain 00065Perm I-Matrix 001 md CH4 Strain 00045Perm J-Matrix 001 md PalmerMansoori exponent 3Perm K-Matrix 0001 md CO2 Langmuir Pressure 240 psiaPerm I-Fracture 02 md CO2 Langmuir Volume 890 scftonPerm J-Fracture 02 md CH4 Langmuir Pressure 402 psiaPerm K-Fracture 002 md CH4 Langmuir Volume 452 scftonPorosity-Matrix 0004 CO2 Sorption time 100 daysPorosity-Fracture 0001 CH4 Sorption time 100 daysRock compressibility-Matrix 100119864119864 119864 0119864 1psi Rock compressibility-Fracture 100119864119864 119864 0119864 1psi
September 2009 [18] 20000 short tons are planned to beinjected through well MH18 and MH20 in two years
Several questions come with this project and need tobe investigated how much CO2 can be stored in this coalseam How long does the injection process take Whichparameters affect the injection and production the mostese questions could be answered by an effective coal seammodel which was represented by a dual-porosity system toshow the uid ow through both matrix and cleat under theparticular conditions in this site e following assumptionswere considered for the modeling and simulation purpose
(1) e initial seam pressure is hydrostatic pressurewhich is 028 psi aer water is produced
(2) e ow in the coal seam is single phase includingonly CH4 and CO2
(3) e uid ow in the cleat system is a laminar ow dueto the larger pore size and it is governed by DarcyrsquosLaw while the ow in the matrix is a diffusional owdue to smaller pore size and governed by Fickrsquos Law
(4) Palmer and Mansoori equation is used to allow thenatural permeability and porosity to vary as a func-tion of pressure
In most cases the actual in situ seam data is unavailablewhich leads to the requirements of some assumptions oncertain parameters such as in this case matrixcleat per-meability matrixcleat porosity geo-mechanical properties(Youngrsquos modulus Poisson ratio) and so forth Table 1summarizes the initial physical parameters in the model
3 History-Matching Results and Discussion
As indicated before the CO2 sequestration-ECBM produc-tion project went through three stages primary methane(CBM) recovery CO2 injection and secondary methane(ECBM) recovery MH18 and MH20 were rstly performedas production wells from January 2005 to July 2007 witha following two-year shut in period thereaer they weretransferred into CO2 injection wells since September 2009MH5 and MH11 keep on methane production from the all
the way from beginning to present All well productions andinjection were simulated starting from the start day until thedate the most updated data have been recorded and reported(August 2012 in this paper)
However different performance of MH18 and MH20 indifferent time periods introduced a lot of complexity on thehistorymatching process A key factor should be respected inthe history matching either for initial methane productionor the following CO2 injection well properties (MH18 orMH20) must stay the same in the model thereby what waschanged is only the operation type
e results of sensitivity analysis were very valuablein back and forth model parameter adjustment Sensitiv-ity analysis is known as the study of how the variation(uncertainty) in the output of a mathematical model canbe apportioned qualitatively or quantitatively affected bythe change of different variations in the input of the model[19] Sensitivity analysis of coalmodeling properties is widelystudied and is addressed that it will be an important toolin future decision making [19ndash21] In this case relatedcoal parameters including cleat permeability porosity CH4desorption time CO2 desorption time CH4 Langmuir vol-ume CO2 Langmuir volume and Palmer and Mansooriparameters have been tested in themodele comparison ofcoal physical property inuences can be concluded based onthe study result as Youngrsquos modulus and Poisson ratio havelittle effect while sorption time cleat permeability strainand Langmuir isotherm are the key parameters that affectCH4 production and CO2 injection most
e actual in-seamdata for bothmethane production andCO2 injection in Upper Freeport coal seam were reporteddaily as shown in Figure 3 e average minimum bottomhole pressure in production wells is 20 psia and the averagemaximum BHP in injection wells is 900 psia e dailyinjection rate is set as constrainte trend could be observedin the production the methane production rate has clearlyincreased in MH5 and MH11 aer July 2009 due to the CO2injection A gradual decline trend in injection rate can benoticed in the injection wells especially in MH18 whichcan be a consequence of the permeability changes occurringduring desorptionadsorption process on coal
4 Journal of Petroleum Engineering
0
100
Date
Production rate
908070605040302010
0
Gas
rat
e (s
cfd
ay)
12
10
8
6
4
2
times103times103
11
42
00
4
52
82
00
5
10
10
20
06
22
22
00
8
76
20
09
11
18
20
10
41
20
12
81
42
01
3
MH11
MH5
(a)
MH20
MH18
Date
Production rate
81
20
04
21
72
00
5
95
20
05
32
42
00
6
10
10
20
06
42
82
00
7
11
14
20
07
Gas
rat
e (c
fd)
80
70
60
50
40
30
20
10
0
160
140
120
100
80
60
40
20
0
times103times103
(b)
Date
Injection rate
Gas
rat
e (s
cfd
ay)
300
250
200
150
100
50
0
140
120
100
80
60
40
20
0
MH18 injMH20 inj
76
20
09
12
22
01
0
81
02
01
0
22
62
01
1
91
42
01
1
41
20
12
10
18
20
12
times103times103
(c)
F 3 Actual CH4 production rateCO2 injection rate in Upper Freeport coal seam (a) CH4 production rate inMH11 andMH5 (b) CH4production rate in MH18 and MH20 (c) CO2 injection rate in MH18_inj and MH20_inj (MH18 and MH20 aer conversion to Injectionwells)
No regular tracking pattern of daily rate was observedbecause of frequent shut-in operations due to weather equip-ment damage or other unpredictable reasons during theinjection process erefore cumulative rates are consideredto be the history matching target by setting bottom holepressure as constraints in the model History matching wasperformed for si wells and nal eisting reservoir prop-erties including permeability porosity Langmuir isothermparameter sorption time and so forth as appropriatewere determined by history matching e history matchingresults are illustrated in Figures 4 and 5 and the coalparameters are listed in Table 2 It is important to note thatthe degree of component isotherm and sorption time at anygiven in-situ condition is directly related to the rank of thecoal Values may change in a large range from different coalseams
Figure 4 shows the fairly good history matching result ofCH4 cumulative production for all production wells Greenline and red line represents the simulated result and actualdata respectively As shown in Figure 4(a) well5 was shut
in from July 2007 to April 2009 and October 2010 to March2011 which can be seen from two short straight lines in redcumulative curves 7 times 106 3 CH4 could be produced fromwell5 by August 2012 with a stable increase As illustratedin Figure 4(b) well11 had a short shut-in period of threemonths that is why no production increase is shown inOctober 2005 and from July 2008 to November 2008 Totally2 times 107 3 CH4 were produced from well11 by August 2012a sharp build-up could be observed aer the start of largeCO2 injection on September 2009 which is because of ECBMproduction Figures 4(c) and 4(d) show the cumulative CH4production of well18 and well20 from January 2005 to July2007 respectively before they were shut-in and transferred toCO2 injection well MH18 produced 16 times 107 3 CH4 whileMH20 had a total of 1 times 107 3 CH4 production at the end ofproduction period
Figure 5 shows cumulative CO2 injection history match-ing in MH18 andMH20 aer they were converted into injec-tion wells Red dashed line represents actual CO2 injection
Journal of Petroleum Engineering 5
Date
Simulated result
Actual result
Well5
52
82
00
5
10
10
20
06
22
22
00
8
76
20
09
11
18
20
10
41
20
12
81
42
01
3
3E+07
25E+07
2E+07
15E+07
1E+07
5E+06
0E+00
Cu
mu
lati
ve g
as r
ate
(ft3
)
(a)
11
42
00
4
52
82
00
5
10
10
20
06
22
22
00
8
76
20
09
11
18
20
10
41
20
12
81
42
01
3
Well11
Date
Simulated result
Actual result
3E+07
25E+07
2E+07
15E+07
1E+07
5E+06
0E+00
Cu
mu
lati
ve g
as r
ate
(ft3
)
(b)
Simulated result
Actual result
Well18
81
20
04
21
72
00
5
95
20
05
32
42
00
6
10
10
20
06
42
82
00
7
11
14
20
07
Date
3E+07
25E+07
2E+07
15E+07
1E+07
5E+06
0E+00
Cu
mu
lati
ve g
as r
ate
(ft3
)
(c)
Simulated result
Actual result
Date
81
20
04
21
72
00
5
95
20
05
32
42
00
6
10
10
20
06
42
82
00
7
11
14
20
07
Well203E+07
25E+07
2E+07
15E+07
1E+07
5E+06
0E+00
Cu
mu
lati
ve g
as r
ate
(ft3
)
(d)
F 4 CH4 cumulative production history matching (a) CH4 cumulative production in MH5 (b) CH4 cumulative production in MH11(c) CH4 cumulative production in MH18 (d) CH4 cumulative production in MH20
data from September 2009 to August 2012 while green lineshows simulation results for both wells Certain plateauscould be seen in the curves during the whole injectionperiods which is because of the shut-in times resultingfrom operational reasons such as weather affects equipmentdamage and so forth More CO2 was injected through well18(maximum amount of 25 times 107 3 CO2) compared to 25 times107 3 CO2 injection in well20 e total amount of injectedCO2 through MH18 and MH20 has been almost 3000 tonsin the rst three years with an average ECM increase of anapproximation of 6700 scfday
4 CO2 Sequestration Capacity in Coal Seam
ere are four main CO2 storage mechanisms in coal seams(a) stratigraphic and structural trapping (b) hydrodynamictrapping (c) mineral trapping and (d) adsorption trappingIn un-mineable coal seams adsorption trapping is the mainsequestration method is is the process of accumulation ofinjected gases which is adsorbed on the surface ofmicropores
within the coal matrix e adsorption capacity will mostlydepend upon Langmuir isotherm factors [22] Figure 6illustrates the nal Langmuir Isotherm in pper Freeportcoal seam in this case
Two assumptions have beenmade in order to simplify thecalculation here
(1) No water production data was reported in this casethe coal reservoir was simulated with single phaseproduction with only CH4 and CO2
(2) Adsorption trapping is the main sequestrationmethod in un-mineable coal seam which wasconsidered as the only storage mechanism withoutincluding free gas in the fractures in this study
e CO2 adsorption capacity in the coal seam can becalculated as
OGIP = 119860119860 times 119860 times 119860119860119887119887 times 119866119866ci = 119881119881 times 119860119860119887119887 times 119866119866ci (4)
where 119881119881119871119871 = 800 scfton 119875119875119871119871 = 412 psia 119875119875 = 028 psi times1200 = 360 psi and 119881119881119881119875119875119881 = 119866119866ci = 119881119881119871119871119875119875119875119881119875119875119871119871 + 119875119875119881 = 800 times
6 Journal of Petroleum Engineering
T 2 History matched reservoir parameter setting
Input parameters Value Unit Input parameters Value UnitAverage reservoir depth 1200 Poisson ratio 03Average formation thickness 4 Youngrsquos Modulus 125000 psiaFracture spacing IJK 0015 CO2 Strain 00025Perm I-Matrix 001ndash002 md CH4 Strain 00045Perm J-Matrix 001ndash002 md PalmerMansoori exponent 3Perm K-Matrix 0001ndash0002 md CO2 Langmuir Pressure 412 psiaPerm I-Fracture 02ndash04 md CO2 Langmuir Volume 800 scftonPerm J-Fracture 02ndash04 md CH4 Langmuir Pressure 628 psiaPerm K-Fracture 002ndash004 md CH4 Langmuir Volume 652 scftonPorosity-Matrix 0002ndash0004 CO2 Sorption time 140 daysPorosity-Fracture 0001ndash0002 CH4 Sorption time 350 daysRock compressibility-Matrix 100119864119864 119864 0119864 1psi Rock compressibility-Fracture 100119864119864 119864 0119864 1psi
Simulated result
Actual result
76
20
09
12
22
01
0
81
02
01
0
22
62
01
1
91
42
01
1
41
20
12
10
18
20
12
Date
Well18 inj
3E+07
25E+07
2E+07
15E+07
1E+07
5E+06
0E+00
Cu
mu
lati
ve g
as r
ate
(ft3
)
(a)
Simulated result
Actual result
76
20
09
12
22
01
0
81
02
01
0
22
62
01
1
91
42
01
1
41
20
12
10
18
20
12
Well20 inj
Date
3E+07
25E+07
2E+07
15E+07
1E+07
5E+06
0E+00
Cu
mu
lati
ve g
as r
ate
(ft3
)
(b)
F 5 Cumulative CO2 injection history matching (a) Cumulative CO2 injection in MH18_inj (b) Cumulative CO2 injection inMH20_inj
Journal of Petroleum Engineering 7
0
100
200
300
400
500
600
700
800
900
0 5000 10000 15000 20000 25000 30000 35000 40000
Langmuir isotherm
Gas
co
nte
nt
(scf
to
n)
Pressure (psia)
CO2
CH4
F 6 Existing Langmuir isotherm for CO2 and CH4 in UpperFreeport Coal seam
360(412 + 360) = 373 scfton where 120588120588119887119887 = 85 lbs3 119881119881 =25193558 3 1 ton = 2000 lbs Coal tonnage = 85 times251935582000 = 1069466 tons OGIP = 1069466 tons times373 scfton17483 tonscf = 22817 tons (coal seam volumeand coal density were provided and were used directly)
5 Summary and Conclusions
e modeling and history matching process of methaneproduction and ECBM as well as CO2 injection in a coal bedseamwas explained in this workis process was performedusing conducting actual data analysis and sensitivity analysisof related coal seam physical properties on four horizontalwells drilled in Upper Freeport coal seam Results of historymatching were compiled to show the initial and existingcondition in the coal seam CO2 sequestration capacity pre-diction was completed according to the Langmuir isothermproperties obtained from the history matched reservoirmodel
e simulation of CH4 gasication and CO2 injectionprocess was quite complicated e special swelling andshrinkage features and the nature of gas retention in CBMreservoirs make the modeling and history matching of pro-duction and injectiondata in coal bedmethanemore complexbecause of the permeability and porosity variations comparedto conventional resources
Sensitivity analysis results suggested that sorption timecleat permeability strain and Langmuir isotherm are themost inuential parameters during CH4 production andCO2injection process It is concluded by the Langmuir isothermparameters from history matched model that the total CO2sequestration capacity is about 22817 tons excluding the freegas part in the cleat system e total CO2 injection amountin the rst three years was 45 times 107 3 or 2600 tons whichcaused an increase of 6700 scfday in CH4 production ratefrom other two wells
Nomenclature
119863119863 Diffusion coefficient119862119862 Average gas concentration in the matrix120591120591 Desorption time days119862119862119891119891((1198751198751198751198751198750)empty0) Stress-dependent permeability term(1198701198701198701198701198751)(119875119875(119875119875+119875119875120576120576)1198751198751198750(1198751198750+119875119875120576120576)(1198701198701198701198701198751)(119875119875(119875119875+119875119875120576120576) 119875 (1198751198750(1198751198750 + 119875119875120576120576)))) Matrix shrinkage termΦ119894119894 Initial fracture porosity 119862119862119891119891 Pore volume compressibility 1psi119875119875 Initial pressure psi119870119870 Axial modulus psi119870119870 Bulk modulus psi120576120576 Langmuir strain119875119875119871119871 Langmuir pressure psi119881119881119871119871 Langmuir volume scfton
119860119860 Drainage area 2
ℎ Net pay
120588120588119887119887 Bulk density lbs3
119866119866ci Gas Content scftonempty119894119894 Porosity119861119861gi Initial formation volume factor STBscfOGIP Original gas in place tons
119881119881 Coal volume 3
Acknowledgments
is project was funded by the Department of EnergyNational Energy Technology Laboratory Consol Energythrough a support contract with URS Energy and Construc-tion Inc e authors want to acknowledge the importantcontributions of Consol Energy for the eld data available foranalysis Acknowledgment is also extended to TomWilson inWVU for providing the geological maps for the studied eldin this researchanks go toComputerModelingGroupLtd(CMG) for providing the soware to do the PEARL researchgroup at WVU
References
[1] S H Stevens D Spector and P Riemer ldquoEnhanced coalbedmethane recovery using CO2 injection worldwide resourceand CO2 sequestration potentialrdquo in Proceedings of the 6thInternational Oil amp Gas Conference and Exhibition in China(IOGCEC rsquo98) pp 489ndash501 Beijing China November 1998
[2] J Ennis-King and L Paterson ldquoEngineering aspects of geo-logical sequestration of carbon dioxiderdquo in Proceedings of thePE sia Pacic Oil and Gas Conference and Exhibition pp134ndash146 Melbourne Australia October 2002
[3] FM Orr Jr ldquoStorage of carbon dioxide in geologic formationsrdquoJournal of Petroleum Technology vol 56 no 9 pp 90ndash97 2004
8 Journal of Petroleum Engineering
[4] C Sinayuccedil and F Guumlmrah ldquoModeling of ECBM recovery fromamasra coalbed in Zonguldak Basin Turkeyrdquo in Proceedingsof the Canadian International Petroleum Conference AlbertaCanada 2008
[5] R Petrusak D Riestenberg P Goad et al ldquoWorld class CO2sequestration potential in saline formations oil and gas eldscoal and shale the US southeast regional carbon sequestrationpartnership has it allrdquo in Proceedings of the SPE InternationalConference on CO2 Capture Storage and Utilization pp136ndash153 November 2009
[6] C L Liner ldquoCarbon capture and sequestration overview andoffshore aspectsrdquo in Proceedings of the Offshore TechnologyConference (OTC rsquo10) pp 3511ndash3514 May 2010
[7] J P Seidle ldquoReservoir engineering aspects of CO2 sequestrationin coalsrdquo in Proceedings of the SPECERI Gas TechnologySymposium Alberta Canada 2000
[8] H J M Pagnier F Van Bergen E Kre L G H VanDer Meer and H J Simmelink ldquoField experiment of ECBM-CO2 in the upper Silesian Basin of Poland (RECOPOL)rdquo inProceedings of the 67th European Association of Geoscientistsand Engineers EAGE Conference and Exhibition incorporatingSPE (EUROPEC rsquo05) pp 3013ndash3015 Madrid Spain June 2005
[9] G A Hernandez R O Bello D A McVay et al ldquoEvaluation ofthe technical and economic feasibility of CO2 sequestration andenhanced coalbed-methane recovery in Texas low-rank coalsrdquoin Proceedings of the SPE Gas Technology Symposium MatureFields to New Frontiers pp 515ndash530 Alberta Canada May2006
[10] G J Koperna and D Riestenberg ldquoCarbon dioxide enhancedcoalbed methane and storage is there promiserdquo in Proceedingsof the SPE International Conference on CO2 Capture Storageand Utilization pp 183ndash195 November 2009
[11] J Q Shi and S Durucan ldquoA model for changes in coalbedpermeability during primary and enhanced methane recoveryrdquoSPE Reservoir Evaluation and Engineering vol 8 no 4 pp291ndash299 2005
[12] S Mazumder and K H Wolf ldquoDifferential swelling andpermeability change of coal in response to CO2 injection forECBMrdquo International Journal of Coal Geology vol 74 no 2 pp123ndash138 2008
[13] L Dean ldquoReservoir engineering for geologists coalbed meth-ane fundamentalsrdquo Reservoir Issue 2007 11
[14] Storing CO2 in Unminable Coal Seams IEA Greenhouse GasRampD Programme
[15] K Aminian and S Ameri ldquoPredicting production performanceof CBM reservoirsrdquo Journal of Natural Gas Science and Engi-neering vol 1 no 1-2 pp 25ndash30 2009
[16] I Zulkamain Simulation study of the effect of well spacingpermeability anisotropy Palmar andMansoori model on coalbedmethane production [MS thesis] Texas AampMUniversity 2005
[17] I Palmer and JMansoori ldquoHowpermeability depends on stressand pore pressure in coalbeds a new modelrdquo SPE ReservoirEngineering vol 1 no 6 pp 539ndash543 1998
[18] ldquoCO2 storage with ECBM studybegins in West VirginiardquohttpwwwcarboncapturejournalcomdisplaynewsphpNewsID=442
[19] D J Remner T Ertekin W Sung and G R King ldquoParametricstudy of the effects of coal seam properties on gas drainageefficiencyrdquo SPE Reservoir Engineering vol 1 no 6 pp 633ndash6461986
[20] A N Okeke Sensitivity analysis of modeling parameters thataffect the dual peaking behavior in coalbed methane reservoirs[MS thesis] Texas AampM University 2005
[21] Q P Huy K Sasaki Y Sugai et al ldquoNumerical simulation ofCO2 enhanced coal bed methane recovery for A vietmese coalseamrdquo JournaL of NoveL Carbon Resource Sciences vol 2 pp1ndash7 2010
[22] D Jasinge and P G Ranjith ldquoCarbon dioxide sequestrationin geologic formation with special reference to sequestrationin deep coal seamsrdquo in Proceedings of the 45th US RockMechanicsGeomechanics Symposium 2011
International Journal of
AerospaceEngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
RoboticsJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Active and Passive Electronic Components
Control Scienceand Engineering
Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
International Journal of
RotatingMachinery
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporation httpwwwhindawicom
Journal ofEngineeringVolume 2014
Submit your manuscripts athttpwwwhindawicom
VLSI Design
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Shock and Vibration
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Civil EngineeringAdvances in
Acoustics and VibrationAdvances in
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Electrical and Computer Engineering
Journal of
Advances inOptoElectronics
Hindawi Publishing Corporation httpwwwhindawicom
Volume 2014
The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
SensorsJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Modelling amp Simulation in EngineeringHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Chemical EngineeringInternational Journal of Antennas and
Propagation
International Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Navigation and Observation
International Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
DistributedSensor Networks
International Journal of
4 Journal of Petroleum Engineering
0
100
Date
Production rate
908070605040302010
0
Gas
rat
e (s
cfd
ay)
12
10
8
6
4
2
times103times103
11
42
00
4
52
82
00
5
10
10
20
06
22
22
00
8
76
20
09
11
18
20
10
41
20
12
81
42
01
3
MH11
MH5
(a)
MH20
MH18
Date
Production rate
81
20
04
21
72
00
5
95
20
05
32
42
00
6
10
10
20
06
42
82
00
7
11
14
20
07
Gas
rat
e (c
fd)
80
70
60
50
40
30
20
10
0
160
140
120
100
80
60
40
20
0
times103times103
(b)
Date
Injection rate
Gas
rat
e (s
cfd
ay)
300
250
200
150
100
50
0
140
120
100
80
60
40
20
0
MH18 injMH20 inj
76
20
09
12
22
01
0
81
02
01
0
22
62
01
1
91
42
01
1
41
20
12
10
18
20
12
times103times103
(c)
F 3 Actual CH4 production rateCO2 injection rate in Upper Freeport coal seam (a) CH4 production rate inMH11 andMH5 (b) CH4production rate in MH18 and MH20 (c) CO2 injection rate in MH18_inj and MH20_inj (MH18 and MH20 aer conversion to Injectionwells)
No regular tracking pattern of daily rate was observedbecause of frequent shut-in operations due to weather equip-ment damage or other unpredictable reasons during theinjection process erefore cumulative rates are consideredto be the history matching target by setting bottom holepressure as constraints in the model History matching wasperformed for si wells and nal eisting reservoir prop-erties including permeability porosity Langmuir isothermparameter sorption time and so forth as appropriatewere determined by history matching e history matchingresults are illustrated in Figures 4 and 5 and the coalparameters are listed in Table 2 It is important to note thatthe degree of component isotherm and sorption time at anygiven in-situ condition is directly related to the rank of thecoal Values may change in a large range from different coalseams
Figure 4 shows the fairly good history matching result ofCH4 cumulative production for all production wells Greenline and red line represents the simulated result and actualdata respectively As shown in Figure 4(a) well5 was shut
in from July 2007 to April 2009 and October 2010 to March2011 which can be seen from two short straight lines in redcumulative curves 7 times 106 3 CH4 could be produced fromwell5 by August 2012 with a stable increase As illustratedin Figure 4(b) well11 had a short shut-in period of threemonths that is why no production increase is shown inOctober 2005 and from July 2008 to November 2008 Totally2 times 107 3 CH4 were produced from well11 by August 2012a sharp build-up could be observed aer the start of largeCO2 injection on September 2009 which is because of ECBMproduction Figures 4(c) and 4(d) show the cumulative CH4production of well18 and well20 from January 2005 to July2007 respectively before they were shut-in and transferred toCO2 injection well MH18 produced 16 times 107 3 CH4 whileMH20 had a total of 1 times 107 3 CH4 production at the end ofproduction period
Figure 5 shows cumulative CO2 injection history match-ing in MH18 andMH20 aer they were converted into injec-tion wells Red dashed line represents actual CO2 injection
Journal of Petroleum Engineering 5
Date
Simulated result
Actual result
Well5
52
82
00
5
10
10
20
06
22
22
00
8
76
20
09
11
18
20
10
41
20
12
81
42
01
3
3E+07
25E+07
2E+07
15E+07
1E+07
5E+06
0E+00
Cu
mu
lati
ve g
as r
ate
(ft3
)
(a)
11
42
00
4
52
82
00
5
10
10
20
06
22
22
00
8
76
20
09
11
18
20
10
41
20
12
81
42
01
3
Well11
Date
Simulated result
Actual result
3E+07
25E+07
2E+07
15E+07
1E+07
5E+06
0E+00
Cu
mu
lati
ve g
as r
ate
(ft3
)
(b)
Simulated result
Actual result
Well18
81
20
04
21
72
00
5
95
20
05
32
42
00
6
10
10
20
06
42
82
00
7
11
14
20
07
Date
3E+07
25E+07
2E+07
15E+07
1E+07
5E+06
0E+00
Cu
mu
lati
ve g
as r
ate
(ft3
)
(c)
Simulated result
Actual result
Date
81
20
04
21
72
00
5
95
20
05
32
42
00
6
10
10
20
06
42
82
00
7
11
14
20
07
Well203E+07
25E+07
2E+07
15E+07
1E+07
5E+06
0E+00
Cu
mu
lati
ve g
as r
ate
(ft3
)
(d)
F 4 CH4 cumulative production history matching (a) CH4 cumulative production in MH5 (b) CH4 cumulative production in MH11(c) CH4 cumulative production in MH18 (d) CH4 cumulative production in MH20
data from September 2009 to August 2012 while green lineshows simulation results for both wells Certain plateauscould be seen in the curves during the whole injectionperiods which is because of the shut-in times resultingfrom operational reasons such as weather affects equipmentdamage and so forth More CO2 was injected through well18(maximum amount of 25 times 107 3 CO2) compared to 25 times107 3 CO2 injection in well20 e total amount of injectedCO2 through MH18 and MH20 has been almost 3000 tonsin the rst three years with an average ECM increase of anapproximation of 6700 scfday
4 CO2 Sequestration Capacity in Coal Seam
ere are four main CO2 storage mechanisms in coal seams(a) stratigraphic and structural trapping (b) hydrodynamictrapping (c) mineral trapping and (d) adsorption trappingIn un-mineable coal seams adsorption trapping is the mainsequestration method is is the process of accumulation ofinjected gases which is adsorbed on the surface ofmicropores
within the coal matrix e adsorption capacity will mostlydepend upon Langmuir isotherm factors [22] Figure 6illustrates the nal Langmuir Isotherm in pper Freeportcoal seam in this case
Two assumptions have beenmade in order to simplify thecalculation here
(1) No water production data was reported in this casethe coal reservoir was simulated with single phaseproduction with only CH4 and CO2
(2) Adsorption trapping is the main sequestrationmethod in un-mineable coal seam which wasconsidered as the only storage mechanism withoutincluding free gas in the fractures in this study
e CO2 adsorption capacity in the coal seam can becalculated as
OGIP = 119860119860 times 119860 times 119860119860119887119887 times 119866119866ci = 119881119881 times 119860119860119887119887 times 119866119866ci (4)
where 119881119881119871119871 = 800 scfton 119875119875119871119871 = 412 psia 119875119875 = 028 psi times1200 = 360 psi and 119881119881119881119875119875119881 = 119866119866ci = 119881119881119871119871119875119875119875119881119875119875119871119871 + 119875119875119881 = 800 times
6 Journal of Petroleum Engineering
T 2 History matched reservoir parameter setting
Input parameters Value Unit Input parameters Value UnitAverage reservoir depth 1200 Poisson ratio 03Average formation thickness 4 Youngrsquos Modulus 125000 psiaFracture spacing IJK 0015 CO2 Strain 00025Perm I-Matrix 001ndash002 md CH4 Strain 00045Perm J-Matrix 001ndash002 md PalmerMansoori exponent 3Perm K-Matrix 0001ndash0002 md CO2 Langmuir Pressure 412 psiaPerm I-Fracture 02ndash04 md CO2 Langmuir Volume 800 scftonPerm J-Fracture 02ndash04 md CH4 Langmuir Pressure 628 psiaPerm K-Fracture 002ndash004 md CH4 Langmuir Volume 652 scftonPorosity-Matrix 0002ndash0004 CO2 Sorption time 140 daysPorosity-Fracture 0001ndash0002 CH4 Sorption time 350 daysRock compressibility-Matrix 100119864119864 119864 0119864 1psi Rock compressibility-Fracture 100119864119864 119864 0119864 1psi
Simulated result
Actual result
76
20
09
12
22
01
0
81
02
01
0
22
62
01
1
91
42
01
1
41
20
12
10
18
20
12
Date
Well18 inj
3E+07
25E+07
2E+07
15E+07
1E+07
5E+06
0E+00
Cu
mu
lati
ve g
as r
ate
(ft3
)
(a)
Simulated result
Actual result
76
20
09
12
22
01
0
81
02
01
0
22
62
01
1
91
42
01
1
41
20
12
10
18
20
12
Well20 inj
Date
3E+07
25E+07
2E+07
15E+07
1E+07
5E+06
0E+00
Cu
mu
lati
ve g
as r
ate
(ft3
)
(b)
F 5 Cumulative CO2 injection history matching (a) Cumulative CO2 injection in MH18_inj (b) Cumulative CO2 injection inMH20_inj
Journal of Petroleum Engineering 7
0
100
200
300
400
500
600
700
800
900
0 5000 10000 15000 20000 25000 30000 35000 40000
Langmuir isotherm
Gas
co
nte
nt
(scf
to
n)
Pressure (psia)
CO2
CH4
F 6 Existing Langmuir isotherm for CO2 and CH4 in UpperFreeport Coal seam
360(412 + 360) = 373 scfton where 120588120588119887119887 = 85 lbs3 119881119881 =25193558 3 1 ton = 2000 lbs Coal tonnage = 85 times251935582000 = 1069466 tons OGIP = 1069466 tons times373 scfton17483 tonscf = 22817 tons (coal seam volumeand coal density were provided and were used directly)
5 Summary and Conclusions
e modeling and history matching process of methaneproduction and ECBM as well as CO2 injection in a coal bedseamwas explained in this workis process was performedusing conducting actual data analysis and sensitivity analysisof related coal seam physical properties on four horizontalwells drilled in Upper Freeport coal seam Results of historymatching were compiled to show the initial and existingcondition in the coal seam CO2 sequestration capacity pre-diction was completed according to the Langmuir isothermproperties obtained from the history matched reservoirmodel
e simulation of CH4 gasication and CO2 injectionprocess was quite complicated e special swelling andshrinkage features and the nature of gas retention in CBMreservoirs make the modeling and history matching of pro-duction and injectiondata in coal bedmethanemore complexbecause of the permeability and porosity variations comparedto conventional resources
Sensitivity analysis results suggested that sorption timecleat permeability strain and Langmuir isotherm are themost inuential parameters during CH4 production andCO2injection process It is concluded by the Langmuir isothermparameters from history matched model that the total CO2sequestration capacity is about 22817 tons excluding the freegas part in the cleat system e total CO2 injection amountin the rst three years was 45 times 107 3 or 2600 tons whichcaused an increase of 6700 scfday in CH4 production ratefrom other two wells
Nomenclature
119863119863 Diffusion coefficient119862119862 Average gas concentration in the matrix120591120591 Desorption time days119862119862119891119891((1198751198751198751198751198750)empty0) Stress-dependent permeability term(1198701198701198701198701198751)(119875119875(119875119875+119875119875120576120576)1198751198751198750(1198751198750+119875119875120576120576)(1198701198701198701198701198751)(119875119875(119875119875+119875119875120576120576) 119875 (1198751198750(1198751198750 + 119875119875120576120576)))) Matrix shrinkage termΦ119894119894 Initial fracture porosity 119862119862119891119891 Pore volume compressibility 1psi119875119875 Initial pressure psi119870119870 Axial modulus psi119870119870 Bulk modulus psi120576120576 Langmuir strain119875119875119871119871 Langmuir pressure psi119881119881119871119871 Langmuir volume scfton
119860119860 Drainage area 2
ℎ Net pay
120588120588119887119887 Bulk density lbs3
119866119866ci Gas Content scftonempty119894119894 Porosity119861119861gi Initial formation volume factor STBscfOGIP Original gas in place tons
119881119881 Coal volume 3
Acknowledgments
is project was funded by the Department of EnergyNational Energy Technology Laboratory Consol Energythrough a support contract with URS Energy and Construc-tion Inc e authors want to acknowledge the importantcontributions of Consol Energy for the eld data available foranalysis Acknowledgment is also extended to TomWilson inWVU for providing the geological maps for the studied eldin this researchanks go toComputerModelingGroupLtd(CMG) for providing the soware to do the PEARL researchgroup at WVU
References
[1] S H Stevens D Spector and P Riemer ldquoEnhanced coalbedmethane recovery using CO2 injection worldwide resourceand CO2 sequestration potentialrdquo in Proceedings of the 6thInternational Oil amp Gas Conference and Exhibition in China(IOGCEC rsquo98) pp 489ndash501 Beijing China November 1998
[2] J Ennis-King and L Paterson ldquoEngineering aspects of geo-logical sequestration of carbon dioxiderdquo in Proceedings of thePE sia Pacic Oil and Gas Conference and Exhibition pp134ndash146 Melbourne Australia October 2002
[3] FM Orr Jr ldquoStorage of carbon dioxide in geologic formationsrdquoJournal of Petroleum Technology vol 56 no 9 pp 90ndash97 2004
8 Journal of Petroleum Engineering
[4] C Sinayuccedil and F Guumlmrah ldquoModeling of ECBM recovery fromamasra coalbed in Zonguldak Basin Turkeyrdquo in Proceedingsof the Canadian International Petroleum Conference AlbertaCanada 2008
[5] R Petrusak D Riestenberg P Goad et al ldquoWorld class CO2sequestration potential in saline formations oil and gas eldscoal and shale the US southeast regional carbon sequestrationpartnership has it allrdquo in Proceedings of the SPE InternationalConference on CO2 Capture Storage and Utilization pp136ndash153 November 2009
[6] C L Liner ldquoCarbon capture and sequestration overview andoffshore aspectsrdquo in Proceedings of the Offshore TechnologyConference (OTC rsquo10) pp 3511ndash3514 May 2010
[7] J P Seidle ldquoReservoir engineering aspects of CO2 sequestrationin coalsrdquo in Proceedings of the SPECERI Gas TechnologySymposium Alberta Canada 2000
[8] H J M Pagnier F Van Bergen E Kre L G H VanDer Meer and H J Simmelink ldquoField experiment of ECBM-CO2 in the upper Silesian Basin of Poland (RECOPOL)rdquo inProceedings of the 67th European Association of Geoscientistsand Engineers EAGE Conference and Exhibition incorporatingSPE (EUROPEC rsquo05) pp 3013ndash3015 Madrid Spain June 2005
[9] G A Hernandez R O Bello D A McVay et al ldquoEvaluation ofthe technical and economic feasibility of CO2 sequestration andenhanced coalbed-methane recovery in Texas low-rank coalsrdquoin Proceedings of the SPE Gas Technology Symposium MatureFields to New Frontiers pp 515ndash530 Alberta Canada May2006
[10] G J Koperna and D Riestenberg ldquoCarbon dioxide enhancedcoalbed methane and storage is there promiserdquo in Proceedingsof the SPE International Conference on CO2 Capture Storageand Utilization pp 183ndash195 November 2009
[11] J Q Shi and S Durucan ldquoA model for changes in coalbedpermeability during primary and enhanced methane recoveryrdquoSPE Reservoir Evaluation and Engineering vol 8 no 4 pp291ndash299 2005
[12] S Mazumder and K H Wolf ldquoDifferential swelling andpermeability change of coal in response to CO2 injection forECBMrdquo International Journal of Coal Geology vol 74 no 2 pp123ndash138 2008
[13] L Dean ldquoReservoir engineering for geologists coalbed meth-ane fundamentalsrdquo Reservoir Issue 2007 11
[14] Storing CO2 in Unminable Coal Seams IEA Greenhouse GasRampD Programme
[15] K Aminian and S Ameri ldquoPredicting production performanceof CBM reservoirsrdquo Journal of Natural Gas Science and Engi-neering vol 1 no 1-2 pp 25ndash30 2009
[16] I Zulkamain Simulation study of the effect of well spacingpermeability anisotropy Palmar andMansoori model on coalbedmethane production [MS thesis] Texas AampMUniversity 2005
[17] I Palmer and JMansoori ldquoHowpermeability depends on stressand pore pressure in coalbeds a new modelrdquo SPE ReservoirEngineering vol 1 no 6 pp 539ndash543 1998
[18] ldquoCO2 storage with ECBM studybegins in West VirginiardquohttpwwwcarboncapturejournalcomdisplaynewsphpNewsID=442
[19] D J Remner T Ertekin W Sung and G R King ldquoParametricstudy of the effects of coal seam properties on gas drainageefficiencyrdquo SPE Reservoir Engineering vol 1 no 6 pp 633ndash6461986
[20] A N Okeke Sensitivity analysis of modeling parameters thataffect the dual peaking behavior in coalbed methane reservoirs[MS thesis] Texas AampM University 2005
[21] Q P Huy K Sasaki Y Sugai et al ldquoNumerical simulation ofCO2 enhanced coal bed methane recovery for A vietmese coalseamrdquo JournaL of NoveL Carbon Resource Sciences vol 2 pp1ndash7 2010
[22] D Jasinge and P G Ranjith ldquoCarbon dioxide sequestrationin geologic formation with special reference to sequestrationin deep coal seamsrdquo in Proceedings of the 45th US RockMechanicsGeomechanics Symposium 2011
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Electrical and Computer Engineering
Journal of
Advances inOptoElectronics
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Volume 2014
The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
SensorsJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Modelling amp Simulation in EngineeringHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Chemical EngineeringInternational Journal of Antennas and
Propagation
International Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Navigation and Observation
International Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
DistributedSensor Networks
International Journal of
Journal of Petroleum Engineering 5
Date
Simulated result
Actual result
Well5
52
82
00
5
10
10
20
06
22
22
00
8
76
20
09
11
18
20
10
41
20
12
81
42
01
3
3E+07
25E+07
2E+07
15E+07
1E+07
5E+06
0E+00
Cu
mu
lati
ve g
as r
ate
(ft3
)
(a)
11
42
00
4
52
82
00
5
10
10
20
06
22
22
00
8
76
20
09
11
18
20
10
41
20
12
81
42
01
3
Well11
Date
Simulated result
Actual result
3E+07
25E+07
2E+07
15E+07
1E+07
5E+06
0E+00
Cu
mu
lati
ve g
as r
ate
(ft3
)
(b)
Simulated result
Actual result
Well18
81
20
04
21
72
00
5
95
20
05
32
42
00
6
10
10
20
06
42
82
00
7
11
14
20
07
Date
3E+07
25E+07
2E+07
15E+07
1E+07
5E+06
0E+00
Cu
mu
lati
ve g
as r
ate
(ft3
)
(c)
Simulated result
Actual result
Date
81
20
04
21
72
00
5
95
20
05
32
42
00
6
10
10
20
06
42
82
00
7
11
14
20
07
Well203E+07
25E+07
2E+07
15E+07
1E+07
5E+06
0E+00
Cu
mu
lati
ve g
as r
ate
(ft3
)
(d)
F 4 CH4 cumulative production history matching (a) CH4 cumulative production in MH5 (b) CH4 cumulative production in MH11(c) CH4 cumulative production in MH18 (d) CH4 cumulative production in MH20
data from September 2009 to August 2012 while green lineshows simulation results for both wells Certain plateauscould be seen in the curves during the whole injectionperiods which is because of the shut-in times resultingfrom operational reasons such as weather affects equipmentdamage and so forth More CO2 was injected through well18(maximum amount of 25 times 107 3 CO2) compared to 25 times107 3 CO2 injection in well20 e total amount of injectedCO2 through MH18 and MH20 has been almost 3000 tonsin the rst three years with an average ECM increase of anapproximation of 6700 scfday
4 CO2 Sequestration Capacity in Coal Seam
ere are four main CO2 storage mechanisms in coal seams(a) stratigraphic and structural trapping (b) hydrodynamictrapping (c) mineral trapping and (d) adsorption trappingIn un-mineable coal seams adsorption trapping is the mainsequestration method is is the process of accumulation ofinjected gases which is adsorbed on the surface ofmicropores
within the coal matrix e adsorption capacity will mostlydepend upon Langmuir isotherm factors [22] Figure 6illustrates the nal Langmuir Isotherm in pper Freeportcoal seam in this case
Two assumptions have beenmade in order to simplify thecalculation here
(1) No water production data was reported in this casethe coal reservoir was simulated with single phaseproduction with only CH4 and CO2
(2) Adsorption trapping is the main sequestrationmethod in un-mineable coal seam which wasconsidered as the only storage mechanism withoutincluding free gas in the fractures in this study
e CO2 adsorption capacity in the coal seam can becalculated as
OGIP = 119860119860 times 119860 times 119860119860119887119887 times 119866119866ci = 119881119881 times 119860119860119887119887 times 119866119866ci (4)
where 119881119881119871119871 = 800 scfton 119875119875119871119871 = 412 psia 119875119875 = 028 psi times1200 = 360 psi and 119881119881119881119875119875119881 = 119866119866ci = 119881119881119871119871119875119875119875119881119875119875119871119871 + 119875119875119881 = 800 times
6 Journal of Petroleum Engineering
T 2 History matched reservoir parameter setting
Input parameters Value Unit Input parameters Value UnitAverage reservoir depth 1200 Poisson ratio 03Average formation thickness 4 Youngrsquos Modulus 125000 psiaFracture spacing IJK 0015 CO2 Strain 00025Perm I-Matrix 001ndash002 md CH4 Strain 00045Perm J-Matrix 001ndash002 md PalmerMansoori exponent 3Perm K-Matrix 0001ndash0002 md CO2 Langmuir Pressure 412 psiaPerm I-Fracture 02ndash04 md CO2 Langmuir Volume 800 scftonPerm J-Fracture 02ndash04 md CH4 Langmuir Pressure 628 psiaPerm K-Fracture 002ndash004 md CH4 Langmuir Volume 652 scftonPorosity-Matrix 0002ndash0004 CO2 Sorption time 140 daysPorosity-Fracture 0001ndash0002 CH4 Sorption time 350 daysRock compressibility-Matrix 100119864119864 119864 0119864 1psi Rock compressibility-Fracture 100119864119864 119864 0119864 1psi
Simulated result
Actual result
76
20
09
12
22
01
0
81
02
01
0
22
62
01
1
91
42
01
1
41
20
12
10
18
20
12
Date
Well18 inj
3E+07
25E+07
2E+07
15E+07
1E+07
5E+06
0E+00
Cu
mu
lati
ve g
as r
ate
(ft3
)
(a)
Simulated result
Actual result
76
20
09
12
22
01
0
81
02
01
0
22
62
01
1
91
42
01
1
41
20
12
10
18
20
12
Well20 inj
Date
3E+07
25E+07
2E+07
15E+07
1E+07
5E+06
0E+00
Cu
mu
lati
ve g
as r
ate
(ft3
)
(b)
F 5 Cumulative CO2 injection history matching (a) Cumulative CO2 injection in MH18_inj (b) Cumulative CO2 injection inMH20_inj
Journal of Petroleum Engineering 7
0
100
200
300
400
500
600
700
800
900
0 5000 10000 15000 20000 25000 30000 35000 40000
Langmuir isotherm
Gas
co
nte
nt
(scf
to
n)
Pressure (psia)
CO2
CH4
F 6 Existing Langmuir isotherm for CO2 and CH4 in UpperFreeport Coal seam
360(412 + 360) = 373 scfton where 120588120588119887119887 = 85 lbs3 119881119881 =25193558 3 1 ton = 2000 lbs Coal tonnage = 85 times251935582000 = 1069466 tons OGIP = 1069466 tons times373 scfton17483 tonscf = 22817 tons (coal seam volumeand coal density were provided and were used directly)
5 Summary and Conclusions
e modeling and history matching process of methaneproduction and ECBM as well as CO2 injection in a coal bedseamwas explained in this workis process was performedusing conducting actual data analysis and sensitivity analysisof related coal seam physical properties on four horizontalwells drilled in Upper Freeport coal seam Results of historymatching were compiled to show the initial and existingcondition in the coal seam CO2 sequestration capacity pre-diction was completed according to the Langmuir isothermproperties obtained from the history matched reservoirmodel
e simulation of CH4 gasication and CO2 injectionprocess was quite complicated e special swelling andshrinkage features and the nature of gas retention in CBMreservoirs make the modeling and history matching of pro-duction and injectiondata in coal bedmethanemore complexbecause of the permeability and porosity variations comparedto conventional resources
Sensitivity analysis results suggested that sorption timecleat permeability strain and Langmuir isotherm are themost inuential parameters during CH4 production andCO2injection process It is concluded by the Langmuir isothermparameters from history matched model that the total CO2sequestration capacity is about 22817 tons excluding the freegas part in the cleat system e total CO2 injection amountin the rst three years was 45 times 107 3 or 2600 tons whichcaused an increase of 6700 scfday in CH4 production ratefrom other two wells
Nomenclature
119863119863 Diffusion coefficient119862119862 Average gas concentration in the matrix120591120591 Desorption time days119862119862119891119891((1198751198751198751198751198750)empty0) Stress-dependent permeability term(1198701198701198701198701198751)(119875119875(119875119875+119875119875120576120576)1198751198751198750(1198751198750+119875119875120576120576)(1198701198701198701198701198751)(119875119875(119875119875+119875119875120576120576) 119875 (1198751198750(1198751198750 + 119875119875120576120576)))) Matrix shrinkage termΦ119894119894 Initial fracture porosity 119862119862119891119891 Pore volume compressibility 1psi119875119875 Initial pressure psi119870119870 Axial modulus psi119870119870 Bulk modulus psi120576120576 Langmuir strain119875119875119871119871 Langmuir pressure psi119881119881119871119871 Langmuir volume scfton
119860119860 Drainage area 2
ℎ Net pay
120588120588119887119887 Bulk density lbs3
119866119866ci Gas Content scftonempty119894119894 Porosity119861119861gi Initial formation volume factor STBscfOGIP Original gas in place tons
119881119881 Coal volume 3
Acknowledgments
is project was funded by the Department of EnergyNational Energy Technology Laboratory Consol Energythrough a support contract with URS Energy and Construc-tion Inc e authors want to acknowledge the importantcontributions of Consol Energy for the eld data available foranalysis Acknowledgment is also extended to TomWilson inWVU for providing the geological maps for the studied eldin this researchanks go toComputerModelingGroupLtd(CMG) for providing the soware to do the PEARL researchgroup at WVU
References
[1] S H Stevens D Spector and P Riemer ldquoEnhanced coalbedmethane recovery using CO2 injection worldwide resourceand CO2 sequestration potentialrdquo in Proceedings of the 6thInternational Oil amp Gas Conference and Exhibition in China(IOGCEC rsquo98) pp 489ndash501 Beijing China November 1998
[2] J Ennis-King and L Paterson ldquoEngineering aspects of geo-logical sequestration of carbon dioxiderdquo in Proceedings of thePE sia Pacic Oil and Gas Conference and Exhibition pp134ndash146 Melbourne Australia October 2002
[3] FM Orr Jr ldquoStorage of carbon dioxide in geologic formationsrdquoJournal of Petroleum Technology vol 56 no 9 pp 90ndash97 2004
8 Journal of Petroleum Engineering
[4] C Sinayuccedil and F Guumlmrah ldquoModeling of ECBM recovery fromamasra coalbed in Zonguldak Basin Turkeyrdquo in Proceedingsof the Canadian International Petroleum Conference AlbertaCanada 2008
[5] R Petrusak D Riestenberg P Goad et al ldquoWorld class CO2sequestration potential in saline formations oil and gas eldscoal and shale the US southeast regional carbon sequestrationpartnership has it allrdquo in Proceedings of the SPE InternationalConference on CO2 Capture Storage and Utilization pp136ndash153 November 2009
[6] C L Liner ldquoCarbon capture and sequestration overview andoffshore aspectsrdquo in Proceedings of the Offshore TechnologyConference (OTC rsquo10) pp 3511ndash3514 May 2010
[7] J P Seidle ldquoReservoir engineering aspects of CO2 sequestrationin coalsrdquo in Proceedings of the SPECERI Gas TechnologySymposium Alberta Canada 2000
[8] H J M Pagnier F Van Bergen E Kre L G H VanDer Meer and H J Simmelink ldquoField experiment of ECBM-CO2 in the upper Silesian Basin of Poland (RECOPOL)rdquo inProceedings of the 67th European Association of Geoscientistsand Engineers EAGE Conference and Exhibition incorporatingSPE (EUROPEC rsquo05) pp 3013ndash3015 Madrid Spain June 2005
[9] G A Hernandez R O Bello D A McVay et al ldquoEvaluation ofthe technical and economic feasibility of CO2 sequestration andenhanced coalbed-methane recovery in Texas low-rank coalsrdquoin Proceedings of the SPE Gas Technology Symposium MatureFields to New Frontiers pp 515ndash530 Alberta Canada May2006
[10] G J Koperna and D Riestenberg ldquoCarbon dioxide enhancedcoalbed methane and storage is there promiserdquo in Proceedingsof the SPE International Conference on CO2 Capture Storageand Utilization pp 183ndash195 November 2009
[11] J Q Shi and S Durucan ldquoA model for changes in coalbedpermeability during primary and enhanced methane recoveryrdquoSPE Reservoir Evaluation and Engineering vol 8 no 4 pp291ndash299 2005
[12] S Mazumder and K H Wolf ldquoDifferential swelling andpermeability change of coal in response to CO2 injection forECBMrdquo International Journal of Coal Geology vol 74 no 2 pp123ndash138 2008
[13] L Dean ldquoReservoir engineering for geologists coalbed meth-ane fundamentalsrdquo Reservoir Issue 2007 11
[14] Storing CO2 in Unminable Coal Seams IEA Greenhouse GasRampD Programme
[15] K Aminian and S Ameri ldquoPredicting production performanceof CBM reservoirsrdquo Journal of Natural Gas Science and Engi-neering vol 1 no 1-2 pp 25ndash30 2009
[16] I Zulkamain Simulation study of the effect of well spacingpermeability anisotropy Palmar andMansoori model on coalbedmethane production [MS thesis] Texas AampMUniversity 2005
[17] I Palmer and JMansoori ldquoHowpermeability depends on stressand pore pressure in coalbeds a new modelrdquo SPE ReservoirEngineering vol 1 no 6 pp 539ndash543 1998
[18] ldquoCO2 storage with ECBM studybegins in West VirginiardquohttpwwwcarboncapturejournalcomdisplaynewsphpNewsID=442
[19] D J Remner T Ertekin W Sung and G R King ldquoParametricstudy of the effects of coal seam properties on gas drainageefficiencyrdquo SPE Reservoir Engineering vol 1 no 6 pp 633ndash6461986
[20] A N Okeke Sensitivity analysis of modeling parameters thataffect the dual peaking behavior in coalbed methane reservoirs[MS thesis] Texas AampM University 2005
[21] Q P Huy K Sasaki Y Sugai et al ldquoNumerical simulation ofCO2 enhanced coal bed methane recovery for A vietmese coalseamrdquo JournaL of NoveL Carbon Resource Sciences vol 2 pp1ndash7 2010
[22] D Jasinge and P G Ranjith ldquoCarbon dioxide sequestrationin geologic formation with special reference to sequestrationin deep coal seamsrdquo in Proceedings of the 45th US RockMechanicsGeomechanics Symposium 2011
International Journal of
AerospaceEngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
RoboticsJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Active and Passive Electronic Components
Control Scienceand Engineering
Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
International Journal of
RotatingMachinery
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporation httpwwwhindawicom
Journal ofEngineeringVolume 2014
Submit your manuscripts athttpwwwhindawicom
VLSI Design
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Shock and Vibration
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Civil EngineeringAdvances in
Acoustics and VibrationAdvances in
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Electrical and Computer Engineering
Journal of
Advances inOptoElectronics
Hindawi Publishing Corporation httpwwwhindawicom
Volume 2014
The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
SensorsJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Modelling amp Simulation in EngineeringHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Chemical EngineeringInternational Journal of Antennas and
Propagation
International Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Navigation and Observation
International Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
DistributedSensor Networks
International Journal of
6 Journal of Petroleum Engineering
T 2 History matched reservoir parameter setting
Input parameters Value Unit Input parameters Value UnitAverage reservoir depth 1200 Poisson ratio 03Average formation thickness 4 Youngrsquos Modulus 125000 psiaFracture spacing IJK 0015 CO2 Strain 00025Perm I-Matrix 001ndash002 md CH4 Strain 00045Perm J-Matrix 001ndash002 md PalmerMansoori exponent 3Perm K-Matrix 0001ndash0002 md CO2 Langmuir Pressure 412 psiaPerm I-Fracture 02ndash04 md CO2 Langmuir Volume 800 scftonPerm J-Fracture 02ndash04 md CH4 Langmuir Pressure 628 psiaPerm K-Fracture 002ndash004 md CH4 Langmuir Volume 652 scftonPorosity-Matrix 0002ndash0004 CO2 Sorption time 140 daysPorosity-Fracture 0001ndash0002 CH4 Sorption time 350 daysRock compressibility-Matrix 100119864119864 119864 0119864 1psi Rock compressibility-Fracture 100119864119864 119864 0119864 1psi
Simulated result
Actual result
76
20
09
12
22
01
0
81
02
01
0
22
62
01
1
91
42
01
1
41
20
12
10
18
20
12
Date
Well18 inj
3E+07
25E+07
2E+07
15E+07
1E+07
5E+06
0E+00
Cu
mu
lati
ve g
as r
ate
(ft3
)
(a)
Simulated result
Actual result
76
20
09
12
22
01
0
81
02
01
0
22
62
01
1
91
42
01
1
41
20
12
10
18
20
12
Well20 inj
Date
3E+07
25E+07
2E+07
15E+07
1E+07
5E+06
0E+00
Cu
mu
lati
ve g
as r
ate
(ft3
)
(b)
F 5 Cumulative CO2 injection history matching (a) Cumulative CO2 injection in MH18_inj (b) Cumulative CO2 injection inMH20_inj
Journal of Petroleum Engineering 7
0
100
200
300
400
500
600
700
800
900
0 5000 10000 15000 20000 25000 30000 35000 40000
Langmuir isotherm
Gas
co
nte
nt
(scf
to
n)
Pressure (psia)
CO2
CH4
F 6 Existing Langmuir isotherm for CO2 and CH4 in UpperFreeport Coal seam
360(412 + 360) = 373 scfton where 120588120588119887119887 = 85 lbs3 119881119881 =25193558 3 1 ton = 2000 lbs Coal tonnage = 85 times251935582000 = 1069466 tons OGIP = 1069466 tons times373 scfton17483 tonscf = 22817 tons (coal seam volumeand coal density were provided and were used directly)
5 Summary and Conclusions
e modeling and history matching process of methaneproduction and ECBM as well as CO2 injection in a coal bedseamwas explained in this workis process was performedusing conducting actual data analysis and sensitivity analysisof related coal seam physical properties on four horizontalwells drilled in Upper Freeport coal seam Results of historymatching were compiled to show the initial and existingcondition in the coal seam CO2 sequestration capacity pre-diction was completed according to the Langmuir isothermproperties obtained from the history matched reservoirmodel
e simulation of CH4 gasication and CO2 injectionprocess was quite complicated e special swelling andshrinkage features and the nature of gas retention in CBMreservoirs make the modeling and history matching of pro-duction and injectiondata in coal bedmethanemore complexbecause of the permeability and porosity variations comparedto conventional resources
Sensitivity analysis results suggested that sorption timecleat permeability strain and Langmuir isotherm are themost inuential parameters during CH4 production andCO2injection process It is concluded by the Langmuir isothermparameters from history matched model that the total CO2sequestration capacity is about 22817 tons excluding the freegas part in the cleat system e total CO2 injection amountin the rst three years was 45 times 107 3 or 2600 tons whichcaused an increase of 6700 scfday in CH4 production ratefrom other two wells
Nomenclature
119863119863 Diffusion coefficient119862119862 Average gas concentration in the matrix120591120591 Desorption time days119862119862119891119891((1198751198751198751198751198750)empty0) Stress-dependent permeability term(1198701198701198701198701198751)(119875119875(119875119875+119875119875120576120576)1198751198751198750(1198751198750+119875119875120576120576)(1198701198701198701198701198751)(119875119875(119875119875+119875119875120576120576) 119875 (1198751198750(1198751198750 + 119875119875120576120576)))) Matrix shrinkage termΦ119894119894 Initial fracture porosity 119862119862119891119891 Pore volume compressibility 1psi119875119875 Initial pressure psi119870119870 Axial modulus psi119870119870 Bulk modulus psi120576120576 Langmuir strain119875119875119871119871 Langmuir pressure psi119881119881119871119871 Langmuir volume scfton
119860119860 Drainage area 2
ℎ Net pay
120588120588119887119887 Bulk density lbs3
119866119866ci Gas Content scftonempty119894119894 Porosity119861119861gi Initial formation volume factor STBscfOGIP Original gas in place tons
119881119881 Coal volume 3
Acknowledgments
is project was funded by the Department of EnergyNational Energy Technology Laboratory Consol Energythrough a support contract with URS Energy and Construc-tion Inc e authors want to acknowledge the importantcontributions of Consol Energy for the eld data available foranalysis Acknowledgment is also extended to TomWilson inWVU for providing the geological maps for the studied eldin this researchanks go toComputerModelingGroupLtd(CMG) for providing the soware to do the PEARL researchgroup at WVU
References
[1] S H Stevens D Spector and P Riemer ldquoEnhanced coalbedmethane recovery using CO2 injection worldwide resourceand CO2 sequestration potentialrdquo in Proceedings of the 6thInternational Oil amp Gas Conference and Exhibition in China(IOGCEC rsquo98) pp 489ndash501 Beijing China November 1998
[2] J Ennis-King and L Paterson ldquoEngineering aspects of geo-logical sequestration of carbon dioxiderdquo in Proceedings of thePE sia Pacic Oil and Gas Conference and Exhibition pp134ndash146 Melbourne Australia October 2002
[3] FM Orr Jr ldquoStorage of carbon dioxide in geologic formationsrdquoJournal of Petroleum Technology vol 56 no 9 pp 90ndash97 2004
8 Journal of Petroleum Engineering
[4] C Sinayuccedil and F Guumlmrah ldquoModeling of ECBM recovery fromamasra coalbed in Zonguldak Basin Turkeyrdquo in Proceedingsof the Canadian International Petroleum Conference AlbertaCanada 2008
[5] R Petrusak D Riestenberg P Goad et al ldquoWorld class CO2sequestration potential in saline formations oil and gas eldscoal and shale the US southeast regional carbon sequestrationpartnership has it allrdquo in Proceedings of the SPE InternationalConference on CO2 Capture Storage and Utilization pp136ndash153 November 2009
[6] C L Liner ldquoCarbon capture and sequestration overview andoffshore aspectsrdquo in Proceedings of the Offshore TechnologyConference (OTC rsquo10) pp 3511ndash3514 May 2010
[7] J P Seidle ldquoReservoir engineering aspects of CO2 sequestrationin coalsrdquo in Proceedings of the SPECERI Gas TechnologySymposium Alberta Canada 2000
[8] H J M Pagnier F Van Bergen E Kre L G H VanDer Meer and H J Simmelink ldquoField experiment of ECBM-CO2 in the upper Silesian Basin of Poland (RECOPOL)rdquo inProceedings of the 67th European Association of Geoscientistsand Engineers EAGE Conference and Exhibition incorporatingSPE (EUROPEC rsquo05) pp 3013ndash3015 Madrid Spain June 2005
[9] G A Hernandez R O Bello D A McVay et al ldquoEvaluation ofthe technical and economic feasibility of CO2 sequestration andenhanced coalbed-methane recovery in Texas low-rank coalsrdquoin Proceedings of the SPE Gas Technology Symposium MatureFields to New Frontiers pp 515ndash530 Alberta Canada May2006
[10] G J Koperna and D Riestenberg ldquoCarbon dioxide enhancedcoalbed methane and storage is there promiserdquo in Proceedingsof the SPE International Conference on CO2 Capture Storageand Utilization pp 183ndash195 November 2009
[11] J Q Shi and S Durucan ldquoA model for changes in coalbedpermeability during primary and enhanced methane recoveryrdquoSPE Reservoir Evaluation and Engineering vol 8 no 4 pp291ndash299 2005
[12] S Mazumder and K H Wolf ldquoDifferential swelling andpermeability change of coal in response to CO2 injection forECBMrdquo International Journal of Coal Geology vol 74 no 2 pp123ndash138 2008
[13] L Dean ldquoReservoir engineering for geologists coalbed meth-ane fundamentalsrdquo Reservoir Issue 2007 11
[14] Storing CO2 in Unminable Coal Seams IEA Greenhouse GasRampD Programme
[15] K Aminian and S Ameri ldquoPredicting production performanceof CBM reservoirsrdquo Journal of Natural Gas Science and Engi-neering vol 1 no 1-2 pp 25ndash30 2009
[16] I Zulkamain Simulation study of the effect of well spacingpermeability anisotropy Palmar andMansoori model on coalbedmethane production [MS thesis] Texas AampMUniversity 2005
[17] I Palmer and JMansoori ldquoHowpermeability depends on stressand pore pressure in coalbeds a new modelrdquo SPE ReservoirEngineering vol 1 no 6 pp 539ndash543 1998
[18] ldquoCO2 storage with ECBM studybegins in West VirginiardquohttpwwwcarboncapturejournalcomdisplaynewsphpNewsID=442
[19] D J Remner T Ertekin W Sung and G R King ldquoParametricstudy of the effects of coal seam properties on gas drainageefficiencyrdquo SPE Reservoir Engineering vol 1 no 6 pp 633ndash6461986
[20] A N Okeke Sensitivity analysis of modeling parameters thataffect the dual peaking behavior in coalbed methane reservoirs[MS thesis] Texas AampM University 2005
[21] Q P Huy K Sasaki Y Sugai et al ldquoNumerical simulation ofCO2 enhanced coal bed methane recovery for A vietmese coalseamrdquo JournaL of NoveL Carbon Resource Sciences vol 2 pp1ndash7 2010
[22] D Jasinge and P G Ranjith ldquoCarbon dioxide sequestrationin geologic formation with special reference to sequestrationin deep coal seamsrdquo in Proceedings of the 45th US RockMechanicsGeomechanics Symposium 2011
International Journal of
AerospaceEngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
RoboticsJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Active and Passive Electronic Components
Control Scienceand Engineering
Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
International Journal of
RotatingMachinery
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporation httpwwwhindawicom
Journal ofEngineeringVolume 2014
Submit your manuscripts athttpwwwhindawicom
VLSI Design
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Shock and Vibration
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Civil EngineeringAdvances in
Acoustics and VibrationAdvances in
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Electrical and Computer Engineering
Journal of
Advances inOptoElectronics
Hindawi Publishing Corporation httpwwwhindawicom
Volume 2014
The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
SensorsJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Modelling amp Simulation in EngineeringHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Chemical EngineeringInternational Journal of Antennas and
Propagation
International Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Navigation and Observation
International Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
DistributedSensor Networks
International Journal of
Journal of Petroleum Engineering 7
0
100
200
300
400
500
600
700
800
900
0 5000 10000 15000 20000 25000 30000 35000 40000
Langmuir isotherm
Gas
co
nte
nt
(scf
to
n)
Pressure (psia)
CO2
CH4
F 6 Existing Langmuir isotherm for CO2 and CH4 in UpperFreeport Coal seam
360(412 + 360) = 373 scfton where 120588120588119887119887 = 85 lbs3 119881119881 =25193558 3 1 ton = 2000 lbs Coal tonnage = 85 times251935582000 = 1069466 tons OGIP = 1069466 tons times373 scfton17483 tonscf = 22817 tons (coal seam volumeand coal density were provided and were used directly)
5 Summary and Conclusions
e modeling and history matching process of methaneproduction and ECBM as well as CO2 injection in a coal bedseamwas explained in this workis process was performedusing conducting actual data analysis and sensitivity analysisof related coal seam physical properties on four horizontalwells drilled in Upper Freeport coal seam Results of historymatching were compiled to show the initial and existingcondition in the coal seam CO2 sequestration capacity pre-diction was completed according to the Langmuir isothermproperties obtained from the history matched reservoirmodel
e simulation of CH4 gasication and CO2 injectionprocess was quite complicated e special swelling andshrinkage features and the nature of gas retention in CBMreservoirs make the modeling and history matching of pro-duction and injectiondata in coal bedmethanemore complexbecause of the permeability and porosity variations comparedto conventional resources
Sensitivity analysis results suggested that sorption timecleat permeability strain and Langmuir isotherm are themost inuential parameters during CH4 production andCO2injection process It is concluded by the Langmuir isothermparameters from history matched model that the total CO2sequestration capacity is about 22817 tons excluding the freegas part in the cleat system e total CO2 injection amountin the rst three years was 45 times 107 3 or 2600 tons whichcaused an increase of 6700 scfday in CH4 production ratefrom other two wells
Nomenclature
119863119863 Diffusion coefficient119862119862 Average gas concentration in the matrix120591120591 Desorption time days119862119862119891119891((1198751198751198751198751198750)empty0) Stress-dependent permeability term(1198701198701198701198701198751)(119875119875(119875119875+119875119875120576120576)1198751198751198750(1198751198750+119875119875120576120576)(1198701198701198701198701198751)(119875119875(119875119875+119875119875120576120576) 119875 (1198751198750(1198751198750 + 119875119875120576120576)))) Matrix shrinkage termΦ119894119894 Initial fracture porosity 119862119862119891119891 Pore volume compressibility 1psi119875119875 Initial pressure psi119870119870 Axial modulus psi119870119870 Bulk modulus psi120576120576 Langmuir strain119875119875119871119871 Langmuir pressure psi119881119881119871119871 Langmuir volume scfton
119860119860 Drainage area 2
ℎ Net pay
120588120588119887119887 Bulk density lbs3
119866119866ci Gas Content scftonempty119894119894 Porosity119861119861gi Initial formation volume factor STBscfOGIP Original gas in place tons
119881119881 Coal volume 3
Acknowledgments
is project was funded by the Department of EnergyNational Energy Technology Laboratory Consol Energythrough a support contract with URS Energy and Construc-tion Inc e authors want to acknowledge the importantcontributions of Consol Energy for the eld data available foranalysis Acknowledgment is also extended to TomWilson inWVU for providing the geological maps for the studied eldin this researchanks go toComputerModelingGroupLtd(CMG) for providing the soware to do the PEARL researchgroup at WVU
References
[1] S H Stevens D Spector and P Riemer ldquoEnhanced coalbedmethane recovery using CO2 injection worldwide resourceand CO2 sequestration potentialrdquo in Proceedings of the 6thInternational Oil amp Gas Conference and Exhibition in China(IOGCEC rsquo98) pp 489ndash501 Beijing China November 1998
[2] J Ennis-King and L Paterson ldquoEngineering aspects of geo-logical sequestration of carbon dioxiderdquo in Proceedings of thePE sia Pacic Oil and Gas Conference and Exhibition pp134ndash146 Melbourne Australia October 2002
[3] FM Orr Jr ldquoStorage of carbon dioxide in geologic formationsrdquoJournal of Petroleum Technology vol 56 no 9 pp 90ndash97 2004
8 Journal of Petroleum Engineering
[4] C Sinayuccedil and F Guumlmrah ldquoModeling of ECBM recovery fromamasra coalbed in Zonguldak Basin Turkeyrdquo in Proceedingsof the Canadian International Petroleum Conference AlbertaCanada 2008
[5] R Petrusak D Riestenberg P Goad et al ldquoWorld class CO2sequestration potential in saline formations oil and gas eldscoal and shale the US southeast regional carbon sequestrationpartnership has it allrdquo in Proceedings of the SPE InternationalConference on CO2 Capture Storage and Utilization pp136ndash153 November 2009
[6] C L Liner ldquoCarbon capture and sequestration overview andoffshore aspectsrdquo in Proceedings of the Offshore TechnologyConference (OTC rsquo10) pp 3511ndash3514 May 2010
[7] J P Seidle ldquoReservoir engineering aspects of CO2 sequestrationin coalsrdquo in Proceedings of the SPECERI Gas TechnologySymposium Alberta Canada 2000
[8] H J M Pagnier F Van Bergen E Kre L G H VanDer Meer and H J Simmelink ldquoField experiment of ECBM-CO2 in the upper Silesian Basin of Poland (RECOPOL)rdquo inProceedings of the 67th European Association of Geoscientistsand Engineers EAGE Conference and Exhibition incorporatingSPE (EUROPEC rsquo05) pp 3013ndash3015 Madrid Spain June 2005
[9] G A Hernandez R O Bello D A McVay et al ldquoEvaluation ofthe technical and economic feasibility of CO2 sequestration andenhanced coalbed-methane recovery in Texas low-rank coalsrdquoin Proceedings of the SPE Gas Technology Symposium MatureFields to New Frontiers pp 515ndash530 Alberta Canada May2006
[10] G J Koperna and D Riestenberg ldquoCarbon dioxide enhancedcoalbed methane and storage is there promiserdquo in Proceedingsof the SPE International Conference on CO2 Capture Storageand Utilization pp 183ndash195 November 2009
[11] J Q Shi and S Durucan ldquoA model for changes in coalbedpermeability during primary and enhanced methane recoveryrdquoSPE Reservoir Evaluation and Engineering vol 8 no 4 pp291ndash299 2005
[12] S Mazumder and K H Wolf ldquoDifferential swelling andpermeability change of coal in response to CO2 injection forECBMrdquo International Journal of Coal Geology vol 74 no 2 pp123ndash138 2008
[13] L Dean ldquoReservoir engineering for geologists coalbed meth-ane fundamentalsrdquo Reservoir Issue 2007 11
[14] Storing CO2 in Unminable Coal Seams IEA Greenhouse GasRampD Programme
[15] K Aminian and S Ameri ldquoPredicting production performanceof CBM reservoirsrdquo Journal of Natural Gas Science and Engi-neering vol 1 no 1-2 pp 25ndash30 2009
[16] I Zulkamain Simulation study of the effect of well spacingpermeability anisotropy Palmar andMansoori model on coalbedmethane production [MS thesis] Texas AampMUniversity 2005
[17] I Palmer and JMansoori ldquoHowpermeability depends on stressand pore pressure in coalbeds a new modelrdquo SPE ReservoirEngineering vol 1 no 6 pp 539ndash543 1998
[18] ldquoCO2 storage with ECBM studybegins in West VirginiardquohttpwwwcarboncapturejournalcomdisplaynewsphpNewsID=442
[19] D J Remner T Ertekin W Sung and G R King ldquoParametricstudy of the effects of coal seam properties on gas drainageefficiencyrdquo SPE Reservoir Engineering vol 1 no 6 pp 633ndash6461986
[20] A N Okeke Sensitivity analysis of modeling parameters thataffect the dual peaking behavior in coalbed methane reservoirs[MS thesis] Texas AampM University 2005
[21] Q P Huy K Sasaki Y Sugai et al ldquoNumerical simulation ofCO2 enhanced coal bed methane recovery for A vietmese coalseamrdquo JournaL of NoveL Carbon Resource Sciences vol 2 pp1ndash7 2010
[22] D Jasinge and P G Ranjith ldquoCarbon dioxide sequestrationin geologic formation with special reference to sequestrationin deep coal seamsrdquo in Proceedings of the 45th US RockMechanicsGeomechanics Symposium 2011
International Journal of
AerospaceEngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
RoboticsJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Active and Passive Electronic Components
Control Scienceand Engineering
Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
International Journal of
RotatingMachinery
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporation httpwwwhindawicom
Journal ofEngineeringVolume 2014
Submit your manuscripts athttpwwwhindawicom
VLSI Design
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Shock and Vibration
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Civil EngineeringAdvances in
Acoustics and VibrationAdvances in
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Electrical and Computer Engineering
Journal of
Advances inOptoElectronics
Hindawi Publishing Corporation httpwwwhindawicom
Volume 2014
The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
SensorsJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Modelling amp Simulation in EngineeringHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Chemical EngineeringInternational Journal of Antennas and
Propagation
International Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Navigation and Observation
International Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
DistributedSensor Networks
International Journal of
8 Journal of Petroleum Engineering
[4] C Sinayuccedil and F Guumlmrah ldquoModeling of ECBM recovery fromamasra coalbed in Zonguldak Basin Turkeyrdquo in Proceedingsof the Canadian International Petroleum Conference AlbertaCanada 2008
[5] R Petrusak D Riestenberg P Goad et al ldquoWorld class CO2sequestration potential in saline formations oil and gas eldscoal and shale the US southeast regional carbon sequestrationpartnership has it allrdquo in Proceedings of the SPE InternationalConference on CO2 Capture Storage and Utilization pp136ndash153 November 2009
[6] C L Liner ldquoCarbon capture and sequestration overview andoffshore aspectsrdquo in Proceedings of the Offshore TechnologyConference (OTC rsquo10) pp 3511ndash3514 May 2010
[7] J P Seidle ldquoReservoir engineering aspects of CO2 sequestrationin coalsrdquo in Proceedings of the SPECERI Gas TechnologySymposium Alberta Canada 2000
[8] H J M Pagnier F Van Bergen E Kre L G H VanDer Meer and H J Simmelink ldquoField experiment of ECBM-CO2 in the upper Silesian Basin of Poland (RECOPOL)rdquo inProceedings of the 67th European Association of Geoscientistsand Engineers EAGE Conference and Exhibition incorporatingSPE (EUROPEC rsquo05) pp 3013ndash3015 Madrid Spain June 2005
[9] G A Hernandez R O Bello D A McVay et al ldquoEvaluation ofthe technical and economic feasibility of CO2 sequestration andenhanced coalbed-methane recovery in Texas low-rank coalsrdquoin Proceedings of the SPE Gas Technology Symposium MatureFields to New Frontiers pp 515ndash530 Alberta Canada May2006
[10] G J Koperna and D Riestenberg ldquoCarbon dioxide enhancedcoalbed methane and storage is there promiserdquo in Proceedingsof the SPE International Conference on CO2 Capture Storageand Utilization pp 183ndash195 November 2009
[11] J Q Shi and S Durucan ldquoA model for changes in coalbedpermeability during primary and enhanced methane recoveryrdquoSPE Reservoir Evaluation and Engineering vol 8 no 4 pp291ndash299 2005
[12] S Mazumder and K H Wolf ldquoDifferential swelling andpermeability change of coal in response to CO2 injection forECBMrdquo International Journal of Coal Geology vol 74 no 2 pp123ndash138 2008
[13] L Dean ldquoReservoir engineering for geologists coalbed meth-ane fundamentalsrdquo Reservoir Issue 2007 11
[14] Storing CO2 in Unminable Coal Seams IEA Greenhouse GasRampD Programme
[15] K Aminian and S Ameri ldquoPredicting production performanceof CBM reservoirsrdquo Journal of Natural Gas Science and Engi-neering vol 1 no 1-2 pp 25ndash30 2009
[16] I Zulkamain Simulation study of the effect of well spacingpermeability anisotropy Palmar andMansoori model on coalbedmethane production [MS thesis] Texas AampMUniversity 2005
[17] I Palmer and JMansoori ldquoHowpermeability depends on stressand pore pressure in coalbeds a new modelrdquo SPE ReservoirEngineering vol 1 no 6 pp 539ndash543 1998
[18] ldquoCO2 storage with ECBM studybegins in West VirginiardquohttpwwwcarboncapturejournalcomdisplaynewsphpNewsID=442
[19] D J Remner T Ertekin W Sung and G R King ldquoParametricstudy of the effects of coal seam properties on gas drainageefficiencyrdquo SPE Reservoir Engineering vol 1 no 6 pp 633ndash6461986
[20] A N Okeke Sensitivity analysis of modeling parameters thataffect the dual peaking behavior in coalbed methane reservoirs[MS thesis] Texas AampM University 2005
[21] Q P Huy K Sasaki Y Sugai et al ldquoNumerical simulation ofCO2 enhanced coal bed methane recovery for A vietmese coalseamrdquo JournaL of NoveL Carbon Resource Sciences vol 2 pp1ndash7 2010
[22] D Jasinge and P G Ranjith ldquoCarbon dioxide sequestrationin geologic formation with special reference to sequestrationin deep coal seamsrdquo in Proceedings of the 45th US RockMechanicsGeomechanics Symposium 2011
International Journal of
AerospaceEngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
RoboticsJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Active and Passive Electronic Components
Control Scienceand Engineering
Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
International Journal of
RotatingMachinery
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporation httpwwwhindawicom
Journal ofEngineeringVolume 2014
Submit your manuscripts athttpwwwhindawicom
VLSI Design
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Shock and Vibration
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Civil EngineeringAdvances in
Acoustics and VibrationAdvances in
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Electrical and Computer Engineering
Journal of
Advances inOptoElectronics
Hindawi Publishing Corporation httpwwwhindawicom
Volume 2014
The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
SensorsJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Modelling amp Simulation in EngineeringHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Chemical EngineeringInternational Journal of Antennas and
Propagation
International Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Navigation and Observation
International Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
DistributedSensor Networks
International Journal of
International Journal of
AerospaceEngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
RoboticsJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Active and Passive Electronic Components
Control Scienceand Engineering
Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
International Journal of
RotatingMachinery
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporation httpwwwhindawicom
Journal ofEngineeringVolume 2014
Submit your manuscripts athttpwwwhindawicom
VLSI Design
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Shock and Vibration
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Civil EngineeringAdvances in
Acoustics and VibrationAdvances in
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Electrical and Computer Engineering
Journal of
Advances inOptoElectronics
Hindawi Publishing Corporation httpwwwhindawicom
Volume 2014
The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
SensorsJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Modelling amp Simulation in EngineeringHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Chemical EngineeringInternational Journal of Antennas and
Propagation
International Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Navigation and Observation
International Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
DistributedSensor Networks
International Journal of
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