Lithofacies distribution and diagenetic overprint of the Jurassic Smackover formation at Little Cedar Creek Field, Conecuh County, Alabama
Upper Jurassic microbial carbonate buildups are proven petroleum reservoirs in southwest Alabama, including at Appleton, Vocation and Little Cedar Creek Fields. For the past 30 years, extensive effort has been applied to describing these microbial fabrics because of their influence on reservoir quality variability. The Smackover Formation at Little Cedar Creek Field in Conecuh County displays microbial lithofacies and reservoirs in a largely undolomitized state. These strata are an ideal dataset to characterize original microbial textures, providing more pristine information to interpret depositional environments and determine the extent that original depositional fabric controlled final reservoir quality. Various classifications of microbial fabrics have also provided models for interpreting depositional history and stratigraphic position of these buildups. This study recognizes five lithofacies in the Smackover Formation: a lower laminated mudstone, a peloidal packstone, a microbial bindstone, a laminated mudstone, and an ooid grainstone. Of the previously published models, Heydari and Baria (2005) provide the best characterization of the units found in Little Cedar Creek. This study enhances the Heydari and Baria (2005) and Mancini et. al. (2008) models by integrating new wells and data gathered in the decade since the model was proposed.