Forecast and mitigation of the pressure build-up in a depleted mine gas reservoir: case study in a French coal basin

A study on the Nord-Pas-de-Calais (NPdC) Mining Basin reveals that the ongoing flooding of underground mine voids, expected to last until 2150, is currently mitigating gas migration due to depleted pressures in some sectors. However, as these voids flood, pressure build-up in isolated sectors poses a significant post-mining risk, potentially leading to hazardous gas emissions at the surface. Researchers from Ineris and GEODERIS used a 3D geometric model of the basin to forecast flooding and pressure changes, aiming to refine the gas monitoring plan. This approach helps prioritize mitigation efforts, such as pressure-relief boreholes, to prevent pressurization in unflooded sectors and anticipate potential failures. The study underscores the need for vigilant monitoring to manage risks associated with mine gas emissions.

Lafortune, S., Gouzy, A., & Vuidart, I. (2023). Forecast and mitigation of the pressure build-up in a depleted mine gas reservoir: case study in a French coal basin. Mine Closure 2023: Proceedings of the 16th International Conference on Mine Closure. https://doi.org/10.36487/acg_repo/2315_011