Diagenesis and reservoir heterogeneity in the Lower Tuscaloosa Formation at Cranfield Field, Mississippi

摘要: The Cretaceous lower Tuscaloosa Formation in the Cranfield Field, Mississippi, is a siliciclastic reservoir and target for geologic CO2 sequestration and enhanced oil recovery (EOR). The reservoir is approximately 3 km deep with an average thickness of 30 m. Samples and data are from six wells at the Cranfield Field including whole cores from four wells and multiple sidewall cores from two wells. The lower Tuscaloosa Formation consists of fining-upward fluvial cycles. The lowermost parts of the fluvial channels are typically composed of conglomerate, and contain a significant component of chert pebbles. The conglomerate is overlain by light gray coarse to medium to finegrained sandstones with minor interbedded mudstone. Petrographic analysis indicates that both original composition and diagenesis extensively affect reservoir heterogeneity. In highly porous and permeable zones, the dominant controls on …