Experimental study of the thermal reaming of the borehole by axial plasmatron

O. Voloshyn¹, I. Potapchuk¹, O. Zhevzhyk², V. Yemelianenko¹, M. Zhovtonoha², M. Sekar³, N. Dhunnoo⁴

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

²Dnipropetrovsk National University of Railway Transport named after Academician V. Lazaryan, Dnipro, Ukraine

³Sathyabama Institute of Science and Technology, Chennai, India

⁴University of Greenwich, London, United Kingdom

Min. miner. depos. 2019, 13(1):103-110

https://doi.org/10.33271/mining13.01.103

Full text (PDF)

ABSTRACT

Purpose. To study rock spallation dynamics in the process of the borehole thermal reaming and analyze energy consumption of the borehole thermal reaming process by plasma jets of the axial plasmatron.

Methods. Field experimental study of rock spallation by plasma jets is carried out with the view to measuring the thermal power of plasma, weight of rock spalls and duration of plasma jets impact on the borehole. VT-200 scales were used to measure the rock spalls weight. In the experimental study, plasma jets flow out directly into the borehole in the granite block. The borehole and plasmatron nozzle parameters are geometrically similar.

Findings. Experimental data are processed in the form of a table that shows the following parameters of individual experiments: duration of the borehole surface treatment by a plasma jet; thermal power of a plasma jet; heat release of a plasma jet, weight of the rock spalls, energy efficiency of the rock spallation process; productivity of the rock destruction. Experimental data are processed in the form of the dependence of energy consumption of the borehole thermal reaming on the duration of the borehole inner surface thermal treatment. The range of thermophysical and plasmodynamic parameters of the plasma torch that allow to achieve rock spallation is determined.

Originality.The linear relationship between the energy consumption in the process of the borehole thermal reaming by low temperature plasma and the duration of the reaming process is revealed, with energy consumption of the reaming process decreasing dramatically with the increase in the process duration.

Practical implications. Methodology of the experimental research into the borehole thermal reaming by plasma jets rock spallation is developed. The results of the study could be applied to borehole drilling processes.

Keywords: borehole, rock destruction, thermal reaming, plasma, spallation, axial plasmatron

REFERENCES

Alymov, B.D., Lebedev, V.Ya., & Trofimov, Yu.E. (1976). Electric arc generator for thermomechanical operational element of the heading machine. Thermomechanical methods of rock destruction (pp. 116-117). Kyiv: Naukova dumka.

Alymov, B.D., Poluyanskiy, S.A., Andreev, A.F., Lebedev, V.Ya., Truskov, I.V., & Storozhuk, N.M. (1969). Integrated researches of plasma generators as effective facilities of thermal impact on rocks in thermomechanical rock breaking elements of heading machines. Thermomechanical methods of rock destruction (pp. 225-229). Kyiv: Naukova dumka.

Bazargan, M., Gudmundsson, A., Meredith, P., Browning, J., & Inskip, N. (2015). Wellbore instability during plasma torch drilling in geothermal reservoirs. Proceedings of the 49th US Rock Mechanics / Geomechanics Symposium, 1-5.

Brkic, D., Kant, M., Meier, T., Schuler, M., & von Roh, R. (2015). Influence of process parameters on thermal rock fracturing under ambient conditions. Proceedings World Geothermal Congress, 1-6.

Dmitriev, A.P., & Goncharov, S.A. (1990). Thermodynamical processes in the rocks. Moscow: Nedra.

Dmitriev, A.P., Goncharov, S.A., & Zilbershmidt, M.G. (2011). Contemporary problems of selective and energy saving rock destruction. Gornyy Informatsionno-Analiticheskiy Byulleten, (1), 169-184.

Dolgopolov, A.V., Truskov, I.V., Andreev, I.F., Alymov, B.D., Kobozev, V.N., Vekhtev, V.E., & Storozhuk, N.M. (1969). Substantiation and test of rational designs of thermomechanical rock breaking elements for heading machines and feature of their operation in narrow slot faces. Thermomechanical methods of rock destruction (pp. 110-113). Kyiv: Naukova dumka.

Epshtein, E.F. (1969). New methods of rock destruction and their development prospects. Thermomechanical methods of rock destruction (pp. 25-31). Kyiv: Naukova dumka.

Falshtynskyi, V., Lozynskyi, V., Saik, P., Dychkovskyi, R., & Tabachenko, M. (2016). Substantiating parameters of stratification cavities formation in the roof rocks during underground coal gasification. Mining of Mineral Deposits, 10(1), 16-24.
https://doi.org/10.15407/mining10.01.016

Kasyanov, V.E., Musolin, V.N., & Snegov, A.I. (1976). Plasma rock breaking elements. Thermomechanical methods of rock destruction (pp. 157-158). Kyiv: Naukova dumka.

Kholyavchenko, L.T., & Osenniy, V.Ya. (1995). Technology and equipment of the borehole plasma reaming for mining enterprises. Plazmotekhnologiya, (95), 221-224.

Kihara, H., Hatano, M., Nakiyama, N., Abe, K., & Nishida, M. (2006). Preliminary studies of spallation particles ejected from an ablator. Transactions of the Japan Society for Aeronautical and Space Sciences, 49(164), 65-70.
https://doi.org/10.2322/tjsass.49.65

Kleshchov, A.Y., & Terentiev, O.M. (2014). Model of the experimental studies of the rock thermal destruction by means of inductive plasma. Energetyka. Tekhnologiya. Ekonomika. Ekologiya, 51-54.

Koshelev, K.V., Tomasov, A.G., & Samoylov, V.L. (1984). Drifting and maintenance experience of mine workings. Sbornik Nauchno-Issledovatelskikh Rabot Ostravskogo Gorno-Metallurgicheskogo Instituta. Seriya Gorno-Geologicheskaya, (2), 21-52.

Lebedev, V.Ya., & Alymov, B.D. (1972). About a possibility of sprung slim holes plasma drilling for underground conditions. Thermomechanical methods of rock destruction. Part 4. Thermal destruction of the rocks by fire flow (pp. 45-48). Kyiv: Naukova dumka.

Meier, T., May, D.A., & von Rohr, P.R. (2016). Numerical investigation of thermal spallation drilling using an uncoupled quasi-static thermoelastic finite element formulation. Journal of Thermal Stresses, 39(9), 1138-1151.
https://doi.org/10.1080/01495739.2016.1193417

Moskalyev, A.N., Pigida, E.Yu., Alymov, B.D., Ignatovich, Yu.M., & Bura, G.G. (1969). Influence of thermal impact on mi-neral composition, structural-textural features, phase changes and microhardness of the rocks. Thermomechanical methods of rock destruction (pp. 55-58). Kyiv: Naukova dumka.

Osenniy, V.Ya. (1997). Investigation results of the thermal reaming of the boreholes in a hard rocks. Plazmotekhno-logiya, (97), 229-232.

Potter, R., Potter, J., & Wideman, T. (2010). Laboratory study and ﬁeld demonstration of hydrothermal spallation drilling. Geothermal Resources Council Transactions, (34), 249-252.

Renusch, D., Rudolphi, M., & Schütze, M. (2010). Software tools for lifetime assessment of thermal barrier coatings. Part I – Thermal ageing failure and thermal fatigue failure. Journal of Solid Mechanics and Materials Engineering, 4(2), 143-154.
https://doi.org/10.1299/jmmp.4.143

Stacey, R., Sanyal, S., Potter, J., & Wideman, T. (2011). Effectiveness of selective borehole enlargement to improve ﬂow performance of geothermal wells. Geothermal Resources Council Transactions, (35), 239-245.

Terentiev, O.M., Kleshchov, A.Y., & Gontar, P. (2015). Expe-riment planning of crystalline structures fracture by inductive plasma flows. Scientific Journal of the Ternopil National Technical University, (1), 134-142.

Walsh, S.D.C., & Lomov, I.N. (2013). Micromechanical mo-deling of thermal spallation in granitic rock. International Journal of Heat and Mass Transfer, (65), 366-373.
https://doi.org/10.1016/j.ijheatmasstransfer.2013.05.043

Wideman, T., Sazdanoff, N., Unzelman-Langsdorf, J., & Potter, J. (2011). Hydrothermal spallation for the treatment of hydrothermal and EGS wells: a cost-effective method for substantially increasing reservoir production and ﬂow rates. Geothermal Resources Council Transactions, (35), 283-285.

Wu, R., Osawa, M., Yokokawa, T., Kawagishi, K., & Harada, H. (2010). Degradation mechanisms of an advanced jet engine service-retired TBC component. Journal of Solid Mechanics and Materials Engineering, 4(2), 119-130.
https://doi.org/10.1299/jmmp.4.119

Yao, M., He, Y., Zhang, W., & Gao, W. (2005). Oxidation resistance of boiler steels with Al2O3–Y2O3 nano- and micro-composite coatings produced by sol-gel process. Materials Transactions, 46(9), 2089-2092.
https://doi.org/10.2320/matertrans.46.2089

Zelenskiy, N.M. (1969). About effectiveness and the prospects of development of thermomechanical rock breaking machines. Thermomechanical methods of rock destruction (pp. 32-38). Kyiv: Naukova dumka.

Zholnach, V.I., Dydzinskiy, V.V., & Slipchenko, V.V. (1972). Study of the thermomechanical destruction process of the hard rocks in an annular face. Thermomechanical methods of rock destruction. Part 3. Processes and technical equipment of thermomechanical rock destruction (pp. 50-52). Kyiv: Naukova dumka.

Zhukov, S.O., & Sorokopud, A.V. (2001). Efficiency augmentation of the combined method of the boreholes drifting. Visnyk ZhITI. Seriya Tekhnichni Nauky, (17), 106-110.