Depositional and diagenetic controls on reservoir quality and petrophysical responses of the DeBroeck Member of the Rodessa Formation in Northwest Louisiana.
Access changed 5/23/22.
The DeBroeck Member of the Lower Cretaceous Rodessa Formation is an overlooked hydrocarbon reservoir in Northwest Louisiana. The formation was deposited on a carbonate platform within the North Louisiana Salt Basin. Core analysis identified fourteen lithofacies within the DeBroeck Member with maximum porosity and permeability values of 21.3% and 49.6 mD. The lithofacies indicate a shallow, open marine depositional environment. Porosity is present as primary interparticle/intraparticle and secondary moldic. Petrographic and SEM imaging show that porosity and permeability are affected by carbonate mud recrystallization and calcite, anhydrite, and pyrite cementation. Diagenesis occurred in three stages: marine, meteoric, and burial, with all stages affecting porosity and permeability. Advanced porosity analysis determined that large amounts of microporosity/irreducible water are present within the formation, causing the resistivity log response to appear ‘water-wet’. Backscatter SEM image analysis shows that pyrite is locally abundant and interconnected within stylolites, which also affects the formation’s petrophysical response.