Reasonable start time of carbon dioxide injection in enhanced coalbed methane recovery involving thermal-hydraulic-mechanical couplings

doi:10.1007/s11707-022-1029-7

Frontiers of Earth Science

2023, Vol. 17

Issue (3): 832-843 https://doi.org/10.1007/s11707-022-1029-7

本期目录

Reasonable start time of carbon dioxide injection in enhanced coalbed methane recovery involving thermal-hydraulic-mechanical couplings

Chaojun FAN¹, Lei YANG¹(

), Bin XIAO¹, Lijun ZHOU², Haiou WEN¹, Hao SUN¹

¹. College of Mining, Liaoning Technical University, Fuxin 123000, China
². College of Safety Science and Engineering, Liaoning Technical University, Huludao 125105, China

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Abstract：

Injection of gas (CO₂) into coal seams is an effective method to benefit from both CO₂ geological storage and coalbed methane recovery. Based on the dual pore structure of coal mass, and the Weibull distribution of fracture permeability, a thermal-hydraulic-mechanical (THM) coupling mathematical model is proposed involving the non-isothermal adsorption of binary gases, dynamic gas diffusion between matrix and fractures, multiphase seepage, coal deformation, heat conduction and heat convection. This mathematical model is applied to study the process of CO₂-enhanced coalbed methane recovery (CO₂-ECBM). Results show that the CH₄ content of CO₂-ECBM in coal seam decreases significantly when compared with that of regular drainage, and decreases rapidly in the early stage but slowly in the later stage. Coal seam permeability evolution is triggered by changes in gas adsorption/desorption, temperature and effective stress. For regular drainage, the early permeability shows a decreasing trend dominated by the increase of effective stress, while the later permeability shows an increasing trend dominated by the CH₄ desorption caused shrinkage of coal matrix. For CO₂-ECBM, the permeability in coal seam generally shows a downward trend due to both matrix swelling induced by gas adsorption and thermal expansion, particularly near injection well. There appears an increased and delayed peak production rate of CH₄. The CH₄ production rate of CO₂-ECBM is always higher than that of regular drainage. The CH₄ cumulative production and CO₂ cumulative storage linearly increase with time, and the CH₄ cumulative production of CO₂-ECBM increased by 39.2% in the duration of 5000 d compared with regular drainage. Reasonable CO₂ injection starting time can overcome the issue of early CO₂ breakthrough and ineffective increase of CH₄ production. In the studied case, the optimal injection starting time is 2500 d. Compared with the simultaneous CH₄ extraction and CO₂ injection, the CH₄ cumulative production of optimal time has increased by 30.1%. The research provides a reference for determining the reasonable CO₂ injection time under similar conditions.

Key words： CO₂ sequestration coalbed methane reasonable injection start time thermo-hydro-mechanical coupling model numerical simulation

收稿日期: 2022-05-25 出版日期: 2023-12-12

Corresponding Author(s): Lei YANG

引用本文:

. [J]. Frontiers of Earth Science, 2023, 17(3): 832-843.
Chaojun FAN, Lei YANG, Bin XIAO, Lijun ZHOU, Haiou WEN, Hao SUN. Reasonable start time of carbon dioxide injection in enhanced coalbed methane recovery involving thermal-hydraulic-mechanical couplings. Front. Earth Sci., 2023, 17(3): 832-843.

链接本文:

https://academic.hep.com.cn/fesci/CN/10.1007/s11707-022-1029-7
https://academic.hep.com.cn/fesci/CN/Y2023/V17/I3/832

Fig.1

Fig.2

Parameter	Value	Parameter	Value
Initial CH₄ pressure in fracture (p_f10, MPa)	5.24	Specific heat capacity of coal (C_s, J/(kg·K))	1350
Initial CH₄ pressure in matrix (p_m10, MPa)	5.24	Specific heat capacity of water (C_w, J/(kg·K))	4187
Initial CO₂ pressure in fracture (p_f20, MPa)	0.2	Specific heat capacity of CH₄ (C_g1, J/(kg·K))	2220
Initial CO₂ pressure in matrix (p_m20, MPa)	0.2	Specific heat capacity of CO₂ (C_g2, J/(kg·K))	844
Young’s modulus of coal seam (E, MPa)	2815	Density of coal (ρ_c, kg·m⁻³)	1470
Young’s modulus of coal skeleton (E_S, MPa)	8469	Klinkenberg factor (b_k, MPa)	0.76
Poisson’s ratio of coal (v)	0.32	Relative permeability of water (k_rw0)	1.0
Fracture stiffness (K_n, GPa/m)	2.8	Relative permeability of gas (k_rg0)	0.875
Langmuir volume constant of CH₄ (V_L1, m³·kg⁻¹)	0.0256	Capillary pressure (p_cgw, MPa)	0.035
Langmuir pressure constant of CH₄ (P_L1, MPa)	2.07	Adsorption time of CH₄ (τ₁, d)	0.221
Langmuir volume constant of CO₂ (V_L2, m³·kg⁻¹)	0.0447	Adsorption time of CO₂ (τ₂, d)	0.334
Langmuir pressure constant of CO₂ (P_L2, MPa)	1.38	Initial temperature in coal seam (T₀, K)	305.5
Dynamic viscosity of CH₄ (μ_g1, 10⁻⁵pa·s)	1.34	Gas molar constant (R, J·mol⁻¹·K⁻¹)	8.314
Dynamic viscosity of CO₂ (μ_g2, 10⁻⁵pa·s)	1.84	Initial porosity of matrix (ϕ_m0)	0.045
Dynamic viscosity of water (μ_w, 10⁻³pa·s)	1.01	Initial porosity of fracture (ϕ_f0)	0.011
Adsorption strain constant of CH₄ (ε_L1)	0.0128	Initial permeability of fracture (k₀, m²)	5.14 × 10⁻¹⁶
Adsorption strain constant of CO₂ (ε_L2)	0.0237	Thermal conductivity of coal (λ_s, W/(m·K))	0.1913
Temperature coefficient (c₁, 1/T)	0.021	Thermal conductivity of CH₄ (λ_g1, W/(m·K))	0.0301
Pressure coefficient (c₂, 1/MPa)	0.071	Thermal conductivity of CO₂ (λ_g2, W/(m·K))	0.0137
Isosteric heat of CH₄ adsorption (q_st1, kJ/mol)	16.4	Initial water saturation (s_w0)	0.8
Isosteric heat of CO₂ adsorption (q_st2, kJ/mol)	19.2	Irreducible water saturation (s_wr)	0.42

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Tab.2

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1	L, Cheng D, Li W, Wang J Liu (2021). Heterogeneous transport of free CH4 and free CO2 in dual-porosity media controlled by anisotropic in situ stress during shale gas production by CO2 flooding: implications for CO2 geological storage and utilization.ACS Omega, 6(40): 26756–26765 https://doi.org/10.1021/acsomega.1c04220 pmid: 34661029
2	C J, Fan D, Elsworth S, Li Z W, Chen M K, Luo Y, Song H H Zhang (2019b). Modelling and optimization of enhanced coalbed methane recovery using CO2/N2 mixtures.Fuel, 253: 1114–1129 https://doi.org/10.1016/j.fuel.2019.04.158
3	C J, Fan D, Elsworth S, Li L J, Zhou Z H, Yang Y Song (2019a). Thermo-hydro-mechanical-chemical couplings controlling CH4 production and CO2 sequestration in enhanced coalbed methane recovery.Energy, 173: 1054–1077 https://doi.org/10.1016/j.energy.2019.02.126
4	C J, Fan S, Li M K, Luo W Z, Du Z H Yang (2017). Coal and gas outburst dynamic system.Int J Min Sci Technol, 27(1): 49–55 https://doi.org/10.1016/j.ijmst.2016.11.003
5	C J, Fan H O, Wen S, Li G, Bai L J Zhou (2022). Coal seam gas extraction by integrated drillings and punchings from the floor roadway considering hydraulic-mechanical coupling effect.Geofluids, 2022: 5198227 https://doi.org/10.1155/2022/5198227
6	C J, Fan L, Yang G, Wang Q M, Huang X, Fu H O Wen (2021a). Investigation on coal skeleton deformation law in CO2 injection enhanced CH4 drainage from underground coal seam.Front Earth Sci, 9: 891
7	Y P, Fan C B, Deng X, Zhang F Q, Li X Y, Wang L Qiao (2018). Numerical study of CO2-enhanced coalbed methane recovery.Int J Greenh Gas Control, 76: 12–23 https://doi.org/10.1016/j.ijggc.2018.06.016
8	Z L, Fan G W, Fan D S, Zhang L, Zhang S, Zhang S S, Liang W Yu (2021b). Optimal injection timing and gas mixture proportion for enhancing coalbed methane recovery.Energy, 222: 119880 https://doi.org/10.1016/j.energy.2021.119880
9	H H, Fang S X, Sang S Q Liu (2019a). Numerical simulation of enhancing coalbed methane recovery by injecting CO2 with heat injection.Petrol Sci, 16(1): 32–43 https://doi.org/10.1007/s12182-018-0291-5
10	H H, Fang S X, Sang S Q Liu (2019b). Establishment of dynamic permeability model of coal reservoir and its numerical simulation during the CO2-ECBM process.J Petrol Sci Eng, 179: 885–898 https://doi.org/10.1016/j.petrol.2019.04.095
11	H H, Fang S X, Sang S Q Liu (2019c). The coupling mechanism of the thermal-hydraulic-mechanical fields in CH4-bearing coal and its application in the CO2-enhanced coalbed methane recovery.J Petrol Sci Eng, 181: 106177 https://doi.org/10.1016/j.petrol.2019.06.041
12	Y D, Hou S P, Huang J, Han X B, Liu L F,Fu C F Han (2020). Numerical simulation of the effect of injected CO2 temperature and pressure on CO2-enhanced coalbed methane.Appl Sci (Basel), 10(4): 1385 https://doi.org/10.3390/app10041385
13	B J, Huo X D, Jing C J, Fan Y L Han (2019). Numerical investigation of flue gas injection enhanced underground coal seam gas drainage.Energy Sci Eng, 7(6): 3204–3219 https://doi.org/10.1002/ese3.491
14	A, Liu S M, Liu P, Liu K Wang (2021a). Water sorption on coal: effects of oxygen-containing function groups and pore structure.Int J Coal Sci Technol, 8(5): 983–1002 https://doi.org/10.1007/s40789-021-00424-6
15	J S, Liu Z W, Chen D, Elsworth X X, Miao X B Mao (2011). Evolution of coal permeability from stress-controlled to displacement-controlled swelling conditions.Fuel, 90(10): 2987–2997 https://doi.org/10.1016/j.fuel.2011.04.032
16	J, Liu L, Xie D, Elsworth Q Gan (2019). CO2/CH4 competitive adsorption in shale: implications for enhancement in gas production and reduction in carbon emissions.Environ Sci Technol, 53(15): 9328–9336 https://doi.org/10.1021/acs.est.9b02432 pmid: 31318200
17	J, Liu Y B, Yao D M, Liu D Elsworth (2017). Experimental evaluation of CO2 enhanced recovery of adsorbed-gas from shale.Int J Coal Geol, 179: 211–218 https://doi.org/10.1016/j.coal.2017.06.006
18	M Y, Liu H, Wen S X, Fan Z P, Wang J B, Fei G M, Wei X J, Cheng H Wang (2022). Experimental Study of CO2-ECBM by injection Liquid CO2.Minerals (Basel), 12(3): 297 https://doi.org/10.3390/min12030297
19	T, Liu B Q, Lin X H, Fu A Liu (2021b). Mechanical criterion for coal and gas outburst: a perspective from multiphysics coupling.Int J Coal Sci Technol, 8(6): 1423–1435 https://doi.org/10.1007/s40789-021-00447-z
20	M K, Luo L, Yang H O, Wen D S, Zhao K Wang (2022). Numerical optimization of drilling parameters for gas predrainage and excavating-drainage collaboration on roadway head.Geofluids, 2022: 3241211 https://doi.org/10.1155/2022/3241211
21	Y L Mu, Y P Fan, J R Wang, N Fan (2019). Numerical study on the injection of heated CO2 to enhance CH4 recovery in water-bearing coal reservoirs. Energy Sources A Recovery Util Environ Effects
22	Q H, Niu W, Wang J J, Liang W, Yuan L, Wen J F, Chang Z M, Ji H, Zhou Z Z, Wang X J Jia (2020). Investigation of the CO2 flooding be havior and its collaborative controlling factors.Energy Fuels, 34(9): 11194–11209 https://doi.org/10.1021/acs.energyfuels.0c01286
23	T, Ren G, Wang Y P, Cheng Q X Qi (2017). Model development and simulation study of the feasibility of enhancing gas drainage efficiency through nitrogen injection.Fuel, 194: 406–422 https://doi.org/10.1016/j.fuel.2017.01.029
24	Y F, Sun Y X, Zhao L Yuan (2018). CO2-ECBM in coal nanostructure: modelling and simulation.J Nat Gas Sci Eng, 54: 202–215 https://doi.org/10.1016/j.jngse.2018.04.007
25	V, Vishal T N, Singh P G Ranjith (2015). Influence of sorption time in CO2-ECBM process in Indian coals using coupled numerical simulation.Fuel, 139: 51–58 https://doi.org/10.1016/j.fuel.2014.08.009
26	G, Wang K, Wang S G, Wang D, Elsworth Y J Jiang (2018). An improved permeability evolution model and its application in fractured sorbing media.J Nat Gas Sci Eng, 56: 222–232 https://doi.org/10.1016/j.jngse.2018.05.038
27	Z L, Wang S X, Sang X Z, Zhou X D Liu (2022). Numerical study on CO2 sequestration in low-permeability coal reservoirs to enhance CH4 recovery: gas driving water and staged inhibition on CH4 output.J Petrol Sci Eng, 214: 110478 https://doi.org/10.1016/j.petrol.2022.110478
28	Y Wu, J S Liu, Z W Chen, D Elsworth, D Pone (2011). A dual poroelastic model for CO2-enhanced coalbed methane recovery. Int J Coal Geol, 86(2–3): 177–189 https://doi.org/10.1016/j.coal.2011.01.004
29	T, Xia F, Zhou F, Gao J, Kang J, Liu J Wang (2015). Simulation of coal self-heating processes in underground methane-rich coal seams.Int J Coal Geol, 141-142: 1–12 https://doi.org/10.1016/j.coal.2015.02.007
30	B, Xiao S G, Liu Z W, Li B, Ran Y H, Ye D, Yang J X Li (2021). Geochemical characteristics of marine shale in the Wufeng Formation–Longmaxi Formation in the northern Sichuan Basin, South China and its implications for depositional controls on organic matter.J Petrol Sci Eng, 203: 108618 https://doi.org/10.1016/j.petrol.2021.108618
31	L, Zhang J H, Li J H, Xue C, Zhang X Q Fang (2021). Experimental studies on the changing characteristics of the gas flow capacity on bituminous coal in CO2-ECBM and N2-ECBM.Fuel, 291: 120115 https://doi.org/10.1016/j.fuel.2020.120115
32	X G, Zhang , Ranjith G P (2019). Experimental investigation of effects of CO2 injection on enhanced methane recovery in coal seam reservoirs.J CO2 Util, 33: 394–404 https://doi.org/10.1016/j.jcou.2019.06.019
33	P, Zhao B, He B, Zhang J Liu (2022). Porosity of gas shale: is the NMR-based measurement reliable?.Petrol Sci, 19(2): 509–517 https://doi.org/10.1016/j.petsci.2021.12.013
34	S J, Zheng Y B, Yao D, Elsworth D M, Liu Y D Cai (2020). Dynamic fluid interactions during CO2-ECBM and CO2 sequestration in coal seams. Part 2: CO2-H2O wettability.Fuel, 279: 118560 https://doi.org/10.1016/j.fuel.2020.118560
35	S J, Zheng Y B, Yao S X, Sang D M, Liu M, Wang S Q Liu (2022). Dynamic characterization of multiphase methane during CO2-ECBM: an NMR relaxation method.Fuel, 324: 124526 https://doi.org/10.1016/j.fuel.2022.124526
36	F D, Zhou F, Hussain Y Cinar (2013). Injecting pure N2 and CO2 to coal for enhanced coalbed methane: experimental observations and numerical simulation.Int J Coal Geol, 116-117: 53–62 https://doi.org/10.1016/j.coal.2013.06.004
37	L J, Zhou X H, Zhou C J, Fan G Bai (2022). Coal permeability evolution triggered by variable injection parameters during gas mixture enhanced methane recovery.Energy, 252: 124065 https://doi.org/10.1016/j.energy.2022.124065
38	Z J, Zhu Z H, Yao J, Nemcik J Han (2022). Investigation of overburden movement and ground stress behaviour in multiseam mining. Lithosphere, 2022(special 11): 3312379

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