Distribution of hydrocarbon source potential in the Jurassic Smackover formation

Abstract

There are regionally consistent differences in source potential between the upper and lower members of the Smackover Formation. Measurements of total organic carbon and visual kerogen assessments indicate that the Lower Smackover has source potential for crude oil from Texas to Florida. Source potential is largely restricted to the laminated lime mudstone facies of the Lower Smackover where deposition occurred in a subtidal environment that was anoxic and probably hypersaline. Algal-derived amorphous kerogen is concentrated in laminations of depositional origin. Carbonate diagenesis during burial enhanced source potential by further concentrating kerogen along stylolites. We suggest that the efficiency of hydrocarbon expulsion has been enhanced by depositional and diagenetic factors that concentrate source rock kerogen along conduits for fluid movement. The Upper Smackover serves mainly as a reservoir rock, and other Jurassic formations lack source potential.