Abstract

Several producing wells along the Falher F trend in the Cutbank area of west central Alberta were examined to determine controls on well productivity and reserve distribution. Three rock types, unimodal conglomerate, bimodal conglomerate and sandstone, were identified, each with unique petrophysical properties, and together forming a continuum from excellent to poor reservoir qualities. These rock types are the result of sediment supply and geological processes associated with a nearshore marine setting. Logs can be readily calibrated to core data and can be used reliably to distinguish conglomerate from sandstone. While deliverability at the wellbore is dominated by unimodal conglomerate, significant volumes of gas flow from bimodal conglomerate to unimodal conglomerate, enhancing recoverable reserves. Sandstones contain gas resource but cannot deliver because of extremely low in situ permeability to gas.