A hydrogeological study of the Debolt reservoir in the SIkanni-Buckinghorse-Grassy area was completed to determine the reason for the generally low recovery factors (50% to 60%) for Debolt gas pools, in particular the Grassy Pool, in this area. Calculations using special core analyses show that, depending on the amounts of the two main reservoir types, the recovery factor could range from as low as 35% to as high as 80% for a likely range of abandonment pressures. Analytical models for the Debolt reservoir in the study area show that it is possible to get a 55% recovery factor, with no reserve bypassing, if the reservoir is composed of about a 25%:75% mix, respectively, of the higher permeability and lower permeability matrices. If the fracturing observed in the reservoir is effective, reserve bypassing could occur and the recovery factors could be even less favourable. A mix of higher and lower permeability matrices would give recovery factors that varied from 50% to 60%, if all of the lower permeability matrix were bypassed by rising water contact in the gas pools.