Abstract
In this study, the effects of synthetic gas flow rates and its viscosity on the crack propagation and cavity growth of the UCG process have been numerically investigated. Numerical modeling is performed using the discrete element method and lattice model, and the effects of flow rate and pre-existing cleat dimensions on the cavity growth have been studied. For this purpose, the fracture fluid pressure, the aperture (primary cleat or secondary cracks aperture), and the number of formed microcracks have been analyzed to evaluate the cavity growth rate. The numerical modeling results show that by increasing the value of syngas flow rate by 2, 5, and 10 times, the fracture fluid pressure and crack aperture increase in the samples. On the other hand, fracture fluid pressure and number of formed microcracks in the UCG process decrease as the pre-existing cleat dimensions increase by 2, 3 and 4 times. As a result, the probability of growth of the cavity decreases. Additionally, the results of numerical models have shown that simultaneous increase of the syngas flow rate and pre-existing cleat dimensions has less effect on crack growth rate in cases that the rate of synthetic gas injection is equal.
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References
Couch GR (2009) Underground coal gasification. IEA Clean Coal Center, International Energy Agency, London, ISBN 978–92–9029–471–9
Burton E, Friedmann J, Upadhye R (2006) Best practices in underground coal gasification. Draft. US DOE contract no W-7405-Eng-48. Livermore, CA, USA, Lawrence Livermore National Laboratory
Bhutto A, Bazmi A, Zahedi G (2013) Underground coal gasification: from fundamentals to applications. Prog Energy Combust Sci 39(1):189–214
Nitao JJ, Camp DW, Buscheck TA, White JA, Burton GC, Wagoner JL, Chen M (2011) Progress on a new integrated 3-D UCG simulator and its initial application. In:International Pittsburgh Coal Conference
Daggupati S, Mandapati RN, Mahajani MS (2010) Laboratory studies on combustion cavity growth in lignite coal blocks in the context of underground coal gasification. Energy 35(6):2374–2386
Perkins G (2005) Mathematical modelling of underground coal gasification. PhD Dissertation, University of New South Wales
Nourozieh H, Kariznovi M, Chen Z, Abedi J (2010) Simulation study of underground coal gasification in Alberta reservoirs: geological structure and process modeling. Energy Fuels 2010:20–24
Su F, Itakura K, Deguchi G, Ohga K (2016) Monitoring of coal fracturing in underground coal gasification by acoustic emission techniques. Appl Energy. https://doi.org/10.1016/j.apenergy.2016.11.082
Shahbazi M, Najafi M, Fatehi Marji M (2019) On the mitigating environmental aspects of a vertical well in underground coal gasification method. Mitig Adapt Strateg Glob Change 24:373–398. https://doi.org/10.1007/s11027-018-9816-x
Wang T, Zhou W, Chen J, Xiaoa X, Li Y, Zhao X (2014) Simulation of hydraulic fracturing using particle flow method and application in a coal mine. Int J Coal Geol 121(2014):1–13. https://doi.org/10.1016/j.coal.2013.10.012
Zhou J, Zhang L, Pan Z, Han Z (2016) Numerical investigation of fluid-driven near-borehole fracture propagation in laminated reservoir rock using PFC2D. J Nat Gas Sci Eng 36:719–733. https://doi.org/10.1016/j.jngse.2016.11.010
Wang T, Hua W, Elsworthc D, Zhoua W, Zhoud W, Zhaoa X, Zhaoa L (2017) The effect of natural fractures on hydraulic fracturing propagation in coal seams. J Pet Sci Eng 150(2017):180–190. https://doi.org/10.1016/j.petrol.2016.12.009
Yoon JS, Zanga A, Stephansson, O, Hofmannb H, Zimmermann G (2017) Discrete element modelling of hydraulic fracture propagation and dynamic interaction with natural fractures in hard rock. Procedia Engineering 191(2017):1023–1031. (http://creativecommons.org/licenses/by-nc-nd/4.0/), Peer-review under responsibility of the organizing committee of EUROCK 2017. https://doi.org/10.1016/j.proeng.2017.05.275
Zhou J, Zhang L (2017) Hydraulic fracturing process by using a modified two-dimensional particle flow code-method and validation. (http://creativecommons.org/licenses/by/4.0/), Computational Fluid Dynamics An International Journal January 2017. https://doi.org/10.1504/PCFD.2017.081719
Abdollahipour A, Marji MF, Bafghi AY, Gholamnejad J (2016a) Time-dependent crack propagation in a poro-elastic medium using a fully coupled hydro-mechanical displacement discontinuity method. Int J Fract 199(1):71–87
Abdollahipour A, Fatehi MM, Yarahmadi Bafghi AR, Gholamnejad J (2016b) Numerical investigation of effect of crack geometrical parameters on hydraulic fracturing process of hydrocarbon reservoirs. J Min Environ 7(2):205–214
Bakhshi E, Rasouli V, Ghorbani A, Fatehi MM, Damjanac B, Wan X (2019) Lattice numerical simulations of lab-scale hydraulic fracture and natural interface interaction. Rock Mech Rock Eng 52(5):1315–1337
Paine AS, Please CP (1994) An improved model of fracture propagation by gas during rock blasting some analytical results. Int. J Rock Mech Min Sci Geomech Abstr. 31(6):699–706. 0148-9062(94)E0003-K.
Goodarzi M, Mohammadi S, Jafari A (2014) Numerical analysis of rock fracturing by gas pressure using the extended finite element method. Pet Sci 12:304–315. https://doi.org/10.1007/s12182-015-0017-x
Munjiza A, Latham JP, and Andrews KRF (2000) Detonation gas model for combined finitediscrete element simulation of fracture and fragmentation. Int. J. Numerical Methods Eng. https://doi.org/10.1002/1097-0207(20001230)49:12<1495::AID-NME7>3.0.CO;2-5.
Nilson RH, Proffer WJ, Duff RE (1985) Modeling of gas-driven fractures induced by propellant combustion within a borehole. Int J Rock Mech Min Sci 22:3–19. https://doi.org/10.1016/0148-9062(85)92589-6
Cho SH, Risei K, Kato M, Nakamura Y, Kaneko K (2002) Development of numerical simulatin method for dyanmic fracture propagation due to gas pressurization and stress wave. ISRM Regional Sym. (3rd Korea-Japan Joint Symposium) on Rock engineering problem and approaches in underground construction
Cho SH, Nakamura Y, Kaneko K (2004) Dynamic fracture process analysis of rock subjected to stress wave and gas pressurization. Int J Rock Mech Min Sci. https://doi.org/10.1016/j.ijrmms.2004.03.079
Xiangchun L, Chao W, Caihong Z, Hua Y (2011) The propagation speed of the cracks in coal body containing gas. The First International Symposium on Mine Safety Science and Engineering. doi:https://doi.org/10.1016/j.ssci.2011.08.004
Zhao Y, Hu Y (1995) Experimental study of the law of effective stress by methane pressure. Chin J Geotech Eng 17(3):26–31 (in Chinese)
Wu S, Zhao W (2005) Analysis of effective stress in adsorbed methane-coal system. Chin J Geotech Eng 24(10):1674–1678 (in Chinese)
Itasca consulting group, Inc. XSite Ver 2.0.73, 2018, (www.itascacg.com)
Maliska CR (2023). Fundamentals of computational fluid dynamics, ISSN 0926–5112, Springer, Volume 135
Engineering toolbox website (www.engineeringtoolbox.com)
Stanczyk K, Kapusta K, Wiatowski M, Swiadrowski J, Smolinski A, Rogut J, Kotyrba A (2011) Experimental simulation of hard coal underground gasification for hydrogen production. Fuel 91(2012):40–50. https://doi.org/10.1016/j.fuel.2011.08.024
Yin Z, Chen Z, Chang J, Hu Z, Ma H, Feng R (2019) Crack initiation characteristics of gas-containing coal under gas pressures. Geofluids 2019:12. https://doi.org/10.1155/2019/5387907
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The authors would like to thank the Iran National Science Foundation (INSF) for supporting this work.
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M. Shahbazi, M. Najafi, M. Fatehi Marji, and A. Abdollahipour declare that they have no competing interests.
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Shahbazi, M., Najafi, M., Fatehi Marji, M. et al. Lattice numerical modeling of the effects of synthetic gas flow rate and pre-existing cleat dimensions on the crack propagation and cavity growth in UCG process. J Braz. Soc. Mech. Sci. Eng. 46, 348 (2024). https://doi.org/10.1007/s40430-024-04893-z
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DOI: https://doi.org/10.1007/s40430-024-04893-z