Pilot-scale studies into methane recovery from mined-out voids of coal mines

After mine closure, methane remains in high quantities in mined-out roadways. By estimates, the volumes of methane in mined-out voids in coal mines exceed by many times the volumes of gas released during coal mining. Russia has no experience in methane recovery from mined-out fields. International practices prove efficient methane extractability from closed mines. This article is devoted to the technology of methane production from coal pillars left in mined-out extraction panels and from mined-out longwalls. The location points of gas-producing wells in a pillar in longwall 24-61 mined-out a few years earlier in Kirov Mine are validated. Hydraulic splitting of pillars from boreholes drilled from ground surface was aimed to open cracks in the pillars in order to extract methane adsorbed in coal and, moreover, to connect the opened cracks with the mined-out void of longwalls to recover free methane from them. The actual data on hydraulic treatment of the old coal pillar and nearby mined-out longwall are presented. It is proved that the hydraulic splitting technology through surface boreholes and at the tested parameters ensures connection of the hydraulic splitting cracks with the mined-out voids in mines and enables methane recovery from the voids and coal pillars. The technology is eco-friendly as it can effectively prevent methane emissions on ground surface above abandoned or closed coal mines, which totally conforms with the methane safety strategy of coal mining in Russia.

Keywords: environmental problems, methane emission on ground surface, coal seam areas nearby mined-out voids, methane recovery from surface boreholes, hydrodynamic treatment, technology of methane recovery from pillars and mined-out voids, stable water injection mode, reliable experimental data.

For citation:

Slastunov S. V., Mazanik E. V., Sadov A. P., Khautiev A. M.-B., Komissarov I. A. Pilot-scale studies into methane recovery from mined-out voids of coal mines. MIAB. Mining Inf. Anal. Bull. 2021;(5):134-145. [In Russ]. DOI: 10.25018/0236_1493_2021_5_0_134.

Acknowledgements:

About authors:

S.V. Slastunov, Dr. Sci. (Eng.), Professor, Mining Institute, National University of Science and Technology «MISiS», 119049, Moscow, Russia, e-mail: slastunovsv@mail.ru,
E.V. Mazanik, Cand. Sci. (Eng.), Advisor to General Director, SUEK-Kuzbass JSC, 652507, Leninsk-Kuznetsky, Russia, e-mail: mazanikev@suek.ru,
A.P. Sadov¹, Cand. Sci. (Eng.), Director, e-mail: sadovap@suek.ru,
A.M.-B. Khautiev¹, Cand. Sci. (Eng.), Engineer-Technologist, e-mail: khautievam@suek.ru,
I.A. Komissarov¹, Deputy Chief Engineer, e-mail: komissarovia@suek.ru,
¹ Methane Degassing and Utilization Department, SUEK-Kuzbass JSC, 652507, Leninsk-Kuznetsky, Russia.

 

For contacts:

S.V. Slastunov, e-mail: slastunovsv@mail.ru.

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