This research is investigating methods of optimizing theremoval of gob region gas through the use of vertical andhorizontal ventilation boreholes. Research tasks include thecollection of transient pressure data from existing gob wells. These data will be evaluated to provide estimates of the volume andproperties of the gob region. The production and pressureperformance of the gob region will be simulated with a finitedifference, coalbed methane reservoir model that can include coaland noncoal strata. Optimization of the gob gas production will beaccomplished by predicting the gob region performance with variousnumbers of vertical and horizontal boreboles. Present estimates ofthe number of gob wells required for efficient gob gas removal,spacing, and placement are based on past experience or on trial anderror rather than on engineering design. Unfortunately, because ofpermeability restrictions that are not yet fully understood,limited numbers of vertical gob ventilation boreboles are notalways sufficient to accommodate gob emissions. Specific problemsto be addressed by the research in Phase I include (1) methods ofinstalling a surface recording downhole pressure gauge in a gobwell, (2) the well testing procedures required to collectsufficient data from which to evaluate the volume and flowproperties of the gob region contributing to production, (3) theanalysis methodology required to estimate gob region propertiesfrom the pressure data, and (4) methods of reservoir simulationrequired to estimate future gob well performance and to optimizegob well design.Anticipated Results/Potential Commercial Applications as described by the awardee:The results of the project will be a reportoutlining methodologies for optimizing gob well placement designand including the data collection and analysis procedures, thesimulation procedures, and the recommended optimum gob well designfor the longwall panel of a cooperative mine operator. Ultimatecommercialization would include data collection, design of anoptimum gob ventilation well system, and installation of such asystem. If sufficiently optimized, nearly 1 BCF per day ofcurrently vented gas may be usable.
