Previous work has shown that the Leduc Formation in the Groat area of the Windfall Complex has pressure drawdown by 1976. This drawdown is attributable to either pre-1976 production from the Leduc Formation at Pine Creek and Windfall or from Beaverhill Lake production at Kaybob South to the northwest. If there is a basal Leduc seal and the potential for a gas trap along the Rosevear to Kaybob trend, the the pressure drawdown in the Leduc at Groat must solely be due to production from Windfall and Pine Creek. The drawdown of the Leduc at Groat would have propagated downdip, through the upper Leduc, along the Windfall Complex. If the drawdown of the Leduc at Groat occurred due to Beaverhill Lake production at Kaybob South, the basal Leduc cannot be an effective deal and a vertical connection is implied. The effectiveness of the Lower Leduc as a vertical seal represents a major risk for the play and thus is the focus of this study.