The most important factors contributing to the effective development of abandoned mine methane resources in the Upper Silesian Coal Basin

Abstract

Abandoned mine methane (AMM) is a by-product of the underground mining of gassy coal seams. Closed and abandoned mines have the potential of accumulating gas which is continuously released over many years after the end of mining. The commercial development of AMM resources is beneficial because economic profits are combined with environmental and safety benefits. Since several gassy coal mines have been closed in recent years, a considerable AMM potential may exist in the Upper Silesian Coal Basin (USCB). To assess AMM resource potential in the USCB, a research project was conducted by the Upper Silesian Branch of the Polish Geological Institute – National Research Institute (PGI-NRI). The project revealed deficiencies in the existing approach to the AMM resource evaluation methodology, and thus a new dynamic method of AMM resources/reserves estimation was developed. The new method was used to estimate the AMM reserves of the seven abandoned mining areas considered prospective for AMM development in the USCB. The results demonstrated that the recovery and utilization of AMM is poorly developed in the USCB. Only three commercial AMM development projects have been implemented over the last 20 years, with a cumulative production of 70 million m3. An understanding of factors contributing to the effective development of AMM resources is important for the long-term planning of AMM utilization in the USCB. Four groups of these factors have been identified based on the PGI-NRI project findings and each group is discussed in detail in this paper. The factors of the first group refer to the knowledge of geological and structural conditions which control permeability and methane content distribution in the basin. The remaining three groups of factors are related to breaking down existing barriers that have common roots in the legal and administrative system, in which appropriate changes are proposed in this article.