Improvement of Intensive In-Seam Gas Drainage Technology at Kirova Mine in Kuznetsk Coal Basin

Abstract

One of the ways to resolve the “green energy-economic development” dilemma, in which the coal industry is situated, is by the improvement of technologies and the integrated use of extracted resources, including methane gas as a clean energy source. Using the example of the Kirova mine, located in Kuznetsk coal basin—one of the ecologically unfavorable coal mining regions of Russia—this article discusses an integrated technology for the extraction of coalbed methane (ECBM), which makes it possible to reduce greenhouse gas (methane) emissions and improve the safety and intensity of coal mining. The Kirova mine, with its 3 Mt production in 2019, is one of the coal mining leaders in Russia. The available mining equipment has the potential to significantly increase the output; however, gas is a limiting factor to this. The customary approaches to coal seam degassing have already been petered out. The miners and mine science are facing a challenge to validate and test an alternative technology to ensure effective in-seam gas drainage prior to vigorous mining. This article gives an account of the improvement track record of the in-seam gas drainage technology used to pre-treat coal seams for intensive and safe extraction. This technology suggests, at the first stage, hydraulic loosening of the target coal seam through wells drilled from the surface (SSHL), then hydraulic fracturing (HF) of the coal seam through the boreholes drilled from underground development headings, followed by methane extraction from the high-permeability coal-gas reservoir created through standard in-seam gas drainage underground wells. Results are presented in this paper of field testing of the improved SSHL technique. Findings are presented on the effective parameters of the HF technology. Methodological recommendations are offered for selecting viable in-seam gas drainage technology.

Optimization of drilling parameters for coal seam gas extraction considering fluid–solid coupling and field application

“…A comprehensive analysis is made on three main factors affecting the efficiency of gas extraction by drilling: borehole diameter, borehole spacing and extraction negative pressure in boreholes, and design orthogonal experiment. The larger the borehole diameter, the higher the gas extraction efficiency, but the large-diameter 17,[25][26][27][28] Design of borehole diameter, spacing, and extraction negative pressure in the borehole three factors each five levels. There are five groups of designed boreholes ranging from 8 cm to 12 dm, with a difference of 0.1 m in each group.…”

“…Therefore, under the premise of ensuring gas extraction efficiency and construction cost. It is very important to find the optimal arrangement parameters of borehole diameter, borehole spacing, and extraction negative pressure in the borehole 17,25–28 …”

“…The variation of coal seam permeability is a geological factor that affects the efficiency of gas extraction, therefore, it is necessary to design boreholes with reasonable parameters to effectively coal seam gas concentration. On the basis of orthogonal experiments to analyze the construction efficiency and stability of the boreholes, the sensitivity effects of each influencing factor were derived 17 18,19 …”

“…On the basis of orthogonal experiments to analyze the construction efficiency and stability of the boreholes, the sensitivity effects of each influencing factor were derived. 17 A multiple linear regression analysis of the borehole parameters was conducted by applying SPSS to the extraction radius as an indicator to derive the degree of influence of each parameter on the effective extraction radius, which can provide some basis for the design of gas parameters. 18,19 Many scholars at home and abroad have focused on the optimization of borehole parameters in terms of a single parameter of the borehole, but the efficiency of gas extraction from boreholes is the result of the joint influence of several borehole parameters, and different boreholes have different degrees of influence on the extraction efficiency, therefore, it is necessary to statistically analyze several borehole parameters to derive the most important parameters and the optimal arrangement values of each parameter of the borehole.…”

On the Issue of Assessing the Automation of Control of the Parameters of the Methane-Air Mixture

“…Метан угольных пластов имеет свойства, близкие с природным га зом, в связи с чем может использоваться в качестве сырья, благодаря чему он стал самостоятельным полезным ископаемым [1,2]. Как ресурс метан угольных пластов является важным и значительным, но уровень его освоенности на данный момент еще не достиг своего пика.…”