Modeling and analysis of gas capture from sealed sections of abandoned coal mines

摘要: Abstract All coal mines eventually complete their economic life, stop production, and are abandoned completely. Ventilation shafts access drifts of these usually sealed by plugging with concrete to isolate the mine environment from outside atmosphere (surface) also prevent unauthorized old workings. Although large areas can be isolated, void space left behind never isolated surrounding other formations. The spaces act as a huge sink start accumulating gas, perhaps groundwater well, over time form methane reservoir. Understanding emission into workings strata, leakage characteristics in-place seals, analyzing gas production potential such improve ventilation designs in operating similar settings, enable possibility using (AMM) an energy source. To meet objectives, data acquired different sources utilized context flow modeling reservoir simulation, along productions AMM wells, invaluable tools. However, for capture may not easy task. difficulties estimating spatial variability various properties environment, complex geometry boundary its details, initial conditions at abandonment when analysis begins all add challenge. In this paper, study that aims characterize extraction room-and-pillar Springfield coal, Indiana, is demonstrated. analyses related interactions were performed though history matching, initially, two wells drilled sections. Analyses then extended evaluate well locations understand changes seals. Data required establishing detailed obtained maps, composite model, geostatistical point-wise create property maps. Results showed larger sections away previous better. Furthermore, location section important close have better chance promoting more in-flow seam, whereas seal take advantage through benefit higher rates contributed parts mine. Since emissions seals vary pressure differential, simulations used design settings estimates thus help improving safety quantified understanding leakage.