This article presents the use of a multi-criterion Analytic Hierarchy Process (AHP) method to assess

geological and mining condition nuisance in longwall mining operations in selected coal mines in Poland.

For this purpose, a methodology has been developed which was used to calculate the operational nuisance

indicator (WUe) in relation to the cost of mining coal in individual longwalls. Components of the aggregate

operational nuisance indicator include four sub-indicators: the natural hazards indicator (UZN), an

indicator describing the seam parameters (UPZ), an indicator describing the technical parameters (UT)

and an environmental impact indicator (UŚ). In total, the impact of 28 different criteria, which formed

particular components of the nuisance indicators were analysed. In total 471 longwalls in 11 coal mines

were analysed, including 277 longwalls that were mined in the period of 2011 to 2016 and 194 longwalls

scheduled for exploitation in the years 2017 to 2021.

Correlation analysis was used to evaluate the relationships between nuisance and the operating costs

of longwalls. The analysis revealed a strong correlation between the level of nuisance and the operating

costs of the longwalls under study. The design of the longwall schedule should therefore also take into

account the nuisance arising from the geological and mining conditions of the operations. Selective

operations management allows for the optimization of costs for mining in underground mines using the

longwall system. This knowledge can also be used to reduce the total operating costs of mines as a result

of abandoning the mining operations in entire longwalls or portions of longwalls that may be permanently

unprofitable. Currently, underground mines do not employ this optimization method, which even more

emphasizes the need for popularizing this approach.

The aim of this paper is an analysis of the variability of the methane content in coal seams in the area of the Dębieńsko Mine and it’s relation to the geological structure of this coal deposit, and also the possibilities of a methane hazard in the areas of future coal mining and methane utilization as a fuel. The Dębieńsko coal deposit is located in the western part of the Upper Silesian Coal Basin (USCB), on the boundary between folded and disjunctive tectonic zones. Coal exploitation in this area ended in 2000, but interest in this deposit is currently high due to plans to initiate coking coal mining. The area of the Dębieńsko mine is relatively well prospected because of the deep drillings (up to 2000 m in depth) carried out within it. The methane conditions of the deposit are varied, the methane content increases with depth according to northern pattern of methane distribution in the USCB, in which the high-methane zone occurs under the several hundred meters zone of natural outgassing of the coal seams. This zone is divided into two smaller methane sub-zones, the first (shallower) at a depth of 1000 m and the second (deeper) at 1700–1900 m. A sub-zone of lower methane content occurs between these two high-methane sub-zones. The most important reasons for this methane distribution are temperature and pressure facilitating the gas adsorption in coal seams, and also the presence of impermeable siltstones and shalestones as well as the maceral composition and coal rank of coal seams. The methane content also changes laterally in accordance with the tectonics of the area. The so called Knurów and Leszczyna Anticline with found increased methane content in coal seams in relation to neighboring areas as well as Orlova Overthrust together with the system of latitudinal faults of brittle tectonic regime which are possible pathways for methane migration play a special role here. These structures can be taken into account as a potential source of methane hazard in a future coal mine, they can also be promising structures for methane prospection as a fuel.