Saint-Petersburg Mining University, Saint-Petersburg, Russia:

K. S. Kupavykh, Assistant, Candidate of Engineering Sciences, Kupavykh_KS@pers.spmi.ru

RENES, Saint-Petersburg, Russia:

A. V. Shipulin, Chief Executive Officer, Candidate of Engineering Sciences

An urgent problem of underground coal mining is high potential coalbed methane hazard. It is proposed to use the method of hydrodynamic treatment of coal based on the pulsed wave effect generated via holes. Since methane is distributed nonuniformly in low-permeable coal, the processes including percussion and vibration effects makes it possible to even pressure in the whole volume of a coal bed and to create favorable conditions for high-rate coalbed methane drainage. Hydraulic impact results in intense fracturing in a coal bed, and different size coal fragments fill the drilled holes. As a consequence, the treated hole becomes highly permeable, which promotes subsequent drainage of coal. The proposed method of coal bed treatment was tested experimentally in full-scale conditions of Kirov’s Mine in Kuzbass. Before and after hydraulic impact, methane concentration was measured in the check and neighbor holes. Additionally, aiming to reveal features of gas behavior in edge coal, miners took check measurements of methane concentrations in the treated and untreated neighbor holes per shift within a day after the experiment. As a result of the experimental hydraulic pulsed treatment of coal, it was observed that methane concentration first sharply grew in the test holes and then dropped to the values close to zero within a day. This is an evidence of efficiency of the hydrodynamic treatment technology in coalbed methane drainage.

1. Puchkov L. A., Slastunov S. V., Kolikov K. S. Methane extraction from coal layers. Moscow : Izdatelstvo MGGU, 2002. 383 p.
2. Viktorov S. D., Zakalinskiy V. M. Large-scale explosive destruction of the rock mass of complex structures with selective mining. Gornyy informatsionno-analiticheskiy byulleten. 2013. Special issue No. 1. Proceedings of international scientific symposium “Miner’s week-2013”. pp. 70–79.
3. Nikolaev N. I., Shipulin A. V., Kupavykh K. S. Energy efficiency improvement of well development. Nauchno-tekhnicheskie vedomosti SPbGPU. Estestvennye i inzhenernye nauki. 2015. No. 2. pp. 48–57.
4. Zhang J. Borehole stability analysis accounting for anisotropies in drilling to weak bedding planes. International Journal of Rock Mechanics and Mining Sciences. 2013. Vol. 60. pp. 160–170.
6. Palmer I. Coalbed methane completions: A world view. International Journal of Coal Geology. 2010. Vol. 82, Iss. 3-4. pp. 184–195.
6. Coal Mine Methane International Activities. United States Environmental Protection Agency, 2017. Available at: https://www.epa.gov/cmop/international-activities (accessed: 22.03.2018).
7. Tagiev S. M. Global extraction of coal layer methane and prospects of this extraction in Kuzbass. Materials of XI International Research and Practice Conference. Sheffield, 2015. Vol. 10. pp. 77–80.
8. Corporate CBM. Natural Gas World. Available at: https://www.naturalgasworld.com/category/coalbed-methane (accessed: 22.03.2018).
9. Cuderman J. F., Northrop D. A. A Propellant-Based Technology for Multiple Fracturing Wellbores to Enhance Gas Recovery: Application and Results in Devonian Shale. SPE Production Engineering. 1986. Vol. 1, Iss. 2. pp. 97–103.
10. Jolly D. C., Morris L. H., Hinsley F. B. An investigation into the relationship between the methane sorption capacity of coal and gas pressure. The Mining Engineer. 1968. Vol. 127, No. 94. pp. 539–548.
11. Coal seam methane. World Coal Association, 2018. Available at: https://www.worldcoal.org/coal/coal-seam-methane (accessed: 05.03.2018).
12. Trofi mov V. A. The main regularities of gas emissions into the hole with a crack of hydraulic fracturing. Gornyy informatsionno-analiticheskiy byulleten. 2013. Special issue No. 1. Proceedings of international scientific symposium “Miner’s Week-2013”. pp. 309–324.
13. Klishin V. I., Tatsienko A. L., Opruk G. Yu. Innovative methods of intensification of the process of degassing of coal seams of preparatory workings. Vestnik of Kuzbass State Technical University. 2017. No. 6. pp. 89–96.

14. Cooley W. C. Rock breakage by pulsed high pressure water jets. Proceedings of the 1^st International Symposium on Jet Cutting Technology. Cranfield, 1972. pp. 125–132.
15. Shipulin A. V., Korshunov G. I., Paltsev A. I., Seregin A. S. Creation of block-fissured structure in coal layer with hydrodynamic effect with the pulse-wave effect. Gornyy informatsionno-analiticheskiy byulleten. 2012. No. 4. pp. 109–112.
16. Shipulin A. V., Korshunov G. I., Meshkov A. A., Mazanik E. V. Method of shock wave destruction of coal seam through wells drilled from excavation. Patent RF, No. 2540709. Applied: 10.12.2013. Published: 10.02.2015. Bulletin No. 4.
17. Nigmatullin R. I., Pyzh V. A., Simonenkov I. D. Anonalous oscillation effect with intensive pressure surges in shock wave, spread by water suspension of bentonitic clay. Izvestiya vuzov. Neft i gaz. 1983. No. 11. pp. 45–47.
18. Rayzer Yu. P. High-frequency charge of high pressure in gas flow as a process of slow burning. Prikladnaya mekhanika i tekhnicheskaya fizika. 1968. No. 3. pp. 3–10.
19. Khanukaev A. N., Mirkin V. G. About the spreading of stress waves during the blast in solid rocks. Zapiski Gornogo instituta imeni Plekhanova. 1962. Vol. 14, No. 1. pp. 3–12.
20. Nikolaev N., Kupavikh K. Well development in complicated conditions. Scientific Reports on Resource Issues. Freiberg : Medienzentrum der TU Bergakademie Freiberg, 2013. Vol. 1. pp. 113–118.