Krukovska V.V. Numerical analysis of influence of coal seams water saturation after water injection on their outburst hazard

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Parent Category: Geo-Technical Mechanics, 2022

Category: Geo-Technical Mechanics, 2022, № 161

Geoteh. meh. 2022, 161, 14-27

https://doi.org/10.15407/geotm2022.161.014

 

NUMERICAL ANALYSIS OF INFLUENCE OF COAL SEAMS WATER SATURATION AFTER WATER INJECTION ON THEIR OUTBURST HAZARD

¹Krukovska V.V.

¹Institute of Geotechnical Mechanics named by N.Poljakov of National Academy of Sciences of Ukraine 

UDC 622.267.53

Language: English

Abstract. The influence of water on the outburst hazard of coal seams by changing the phase permeability and coal properties was investigated. To do this, a numerical model of the gas-dynamic processes in the mine face in the outburst-prone zone near the tectonic fault was developed with taking into account the presence of water in the crack-pore space of coal. Calculations were performed for four cases: without water influence, with the influence of water presence on the change of phase permeability, with its influence on the change of the coefficient of elasticity and Poisson's ratio. Calculation of geomechanical and filtration parameters under conditions of minimum natural moisture saturation s_w = 1% showed that under these boundary and initial conditions there is an outburst of coal and methane in the outburst-hazardous zone. The zone of inelastic deformations rapidly grows from the mine face along the coal seam; pressure gradients near the free surface take very high values; coal and gas outburst takes place and cavity forms. Then geomechanical processes and the process of methane filtration return to the quasi-stationary mode. As a result of calculations with variation of the moisture s_w values in crack-pore space of coal, it was obtained that gas-dynamic processes in the mine face start if s_w < 24%, for the boundary and initial conditions accepted in this work. When this limit is exceeded, geomechanical and filtration processes in the coal seam near the mine face do not start; geomechanical and filtration processes occur in quasi-stationary mode. The effect of moisture on the reduction of phase permeability for methane leads to the neutralization of the outburst-hazardous properties of coal. Additional consideration of the decrease in the coefficient of elasticity and increase in Poisson's ratio due to coal humidification reduces the safe limit of moisture saturation to s_w = 20%. Thus, the regularities of the influence of moisture on the outburst hazard of coal seams were established. The numerical model was developed that allows to identify a safe limit of moisture saturation, at which the nature of geomechanical and filtration processes in the coal seam changes from dynamic to quasi-stationary in specific geological conditions.
Keywords: mining safety, numerical simulation, outburst hazard, permeability to phase, water saturation.

 

REFERENCES:

1. Bulat, A.F., Skipochka, S.I., Palamarchuk, T.A. and Antsyfierov, V.A. (2010), Metanogeneratsiya v ugolnyih plastah [Methane generation in coal seams], Lira LTD, Dnepropetrovsk, Ukraine.

2. Helong, Gua, Ming, Taoa, Xibing, Lia, Aliakbar, Momenib and Wenzhuo, Caoc (2019), “The effects of water content and external incident energy on coal dynamic behavior”, International Journal of Rock Mechanics and Mining Sciences, no.123, рр. 104088. https://doi.org/10.1016/j.ijrmms.2019.104088

3. Makieiev, S.Iu., Pylypenko, Yu.N., Ryzhov, H.A., Andrieiev, S.Iu. and Bobro, M.T. (2012), “Study of the influence of fluids on the deformation properties of coal and rocks under different load conditions”, Suchasni resursoenerhozberihaiuchi tekhnolohii hirnychoho vyrobnytstva, no. 2(10), pp. 73-82.

4. Petuhov, I.M., Litvin, V.A., Kucherskiy, L.V. et al. (1969), Gornyie udaryi i borba s nimi na shahtah kizelovskogo basseyna [Rock bursts and their control in the mines of the Kizel basin], Perm book publishing house, Perm, Russia. 

5. Artamonov, V.N. and Nikolaev, E.B. (2020), “Forecasting changes in dust formation by hydraulic impact during drilling and blasting in coal mines”, Proceedings of the IV scientific-practical conference Donbas 2020: science and technology for production, Donetsk: DonNTU, pp. 89-96.

6. Krukovska, V.V. (2015) “Simulation of coupled processes that occur in coal-rock massif during mining operations”, Geo-Technical Mechanics, no. 121, pp. 48-99.

7. Day, S., Sakurovs, R. and Weir, S. (2008), “Supercritical gas sorption on moist coals”,International Journal of Coal Geology, no. 74, pp. 203-214. https://doi.org/10.1016/j.coal.2008.01.003

8. Sayeed A. Mohammad and Khaled M. Gasem (2012), “Modeling the Competitive Adsorption of CO₂ and Water at High Pressures on Wet Coals”, Energy Fuels, no. 26, pp. 557-568. https://doi.org/10.1021/ef201422e

9. Vasilenko, T.A., Kirillov, A.K., Molchanov, A.N. and others (2013), “Emission of methane from hard coals under conditions of high moisture content”, Fizika i tehnika vyisokih davleniy, vol. 23, no. 3, pp. 121-125.

10. Jian, Xiong, Xiangjun, Liu, Lixi, Liang, Xiaocheng, Wei and Peng, Xu (2019), “Investigation of the factors influencing methane adsorption on illite”, Energy Science & Engineering, no. 7, pp. 3317-3331. https://doi.org/10.1002/ese3.501

11. Mineev, S.P., Potapenko, A.A., Mkhatvary, T.Ia. et al. (2013), Povyishenie effektivnosti gidravlicheskogo ryihleniya vyibrosoopasnyih ugolnyih plastov [Improving the efficiency of hydraulic loosening of outburst-prone coal seams], ShIdniy vidavnichiy dIm, Donetsk, Ukraine.

12. Durucan, S., Daltaban, T.S., Shi, J.Q. and Foley, L. (1993), “Permeability characterization for modeling methane flow in coal seams”, International Coalbed Methane Symposium, Proceedings of Symposium, Tuscaloosa, Alabama, pp. 453-460.

13. Bai, M., Meng, F., Elsworth, D. et al. (1997), “Numerical modeling of stress-dependent permeability”, International Journal of Rock Mechanics & Mining Sciences, no. 34:3-4, pp. 2.e1-2.e14. https://doi.org/10.1016/S1365-1609(97)00056-7

14. Krukovska, V.V. and Kocherga, V.M. (2022), “Influence of the method of gate road protection on the operating efficiency of methane drainage boreholes”, IOP Conference Series, Earth and Environmental Science 2022, vol. 970, no.1, 012045. https://doi.org/10.1088/1755-1315/970/1/012045

15. Krukovskyi, O., Krukovska, V. and Wen, Zhang (2020), “Outburst cavity formation in the working face driven along the outburst-prone coal seam”, E3S Web of Conferences, II International Conference Essays of Mining Science and Practice, no. 168, 00052. https://doi.org/10.1051/e3sconf/202016800052

 

About author:

Krukovska Viktoriia Viktorivna, Doctor of Technical Sciences (D. Sc), Senior Researcher, Senior Researcher in Department of Pressure Dynamics Control in Rocks, Institute of Geotechnical Mechanics named by N. Poljakov of National Academy of Sciences of Ukraine (IGTM NAS of Ukraine), Dnipro, Ukraine, This email address is being protected from spambots. You need JavaScript enabled to view it.

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