Distribution of thermogenic methane in Carboniferous coal seams of the Donets Basin (Ukraine): “Applications to exploitation of methane and forecast of mining hazards”

Abstract

The main purpose of this contribution is to estimate methane production and to define its migration paths and storage in the Donets Basin formations for exploitation of methane and forecast of mining hazards.

In order to study methane migration and storage, maps of production calculated by 2D modelling, adsorption capacity of methane in coal, and present-day methane contents were constructed for an altitude of − 300 m (close to 500 m depth) in this basin. The results show that three principal factors influenced the methane migration and accumulation in Donets Basin: 1) faults that acted as migration pathways, 2) a replacement of thermogenic methane by endogenic CO2 in the central and SE parts, and 3) the occurrence of magmatic events in some areas in this basin. Finally, in Donbas, the areas with the highest methane potential and the maximum risk of outburst are not the areas with anthracite that produce the highest volume of methane, but areas with volatile bituminous coals where an impermeable cover preserved the accumulated gas until the Cenozoic and where dextral shear belts facilitated its migration.