MODELING OF THE BURIAL AND THERMAL HISTORIES OF STRATA IN THE NORTH LOUISIANA SALT BASIN

Burial history and thermal maturation analyses have been performed for strata of the North Louisiana Salt Basin. The tectonic and depositional histories form the foundation for the modeling. Eleven regional cross sections consisting of 141 wells, structural maps, and isopach maps comprise the basis for this study. Information interpreted from well samples, cross sections, and subsurface maps include biostratigraphic, paleoenvironmental, lithologies and stratigraphic thickness of the units, compaction, sediment accumulation and subsidence rates, unconformities and faulting. Basin modeling indicates that variation in sediment accumulation rate is related to lithology, unit thickness, and duration of deposition. The highest mean sediment accumulation and tectonic subsidence rates were recorded for Late Jurassic and Early Cretaceous strata. Thermal maturity modeling was accomplished utilizing vitrinite reflectance, thermal alternation index, Tmax, bottom hole temperature, type of kerogen and total organic carbon data. Maturity modeling indicates that Upper Jurassic carbonate mudstones were effective regional source rocks throughout the basin. Oil generation commenced from these carbonate mudstones in the Early to Late Cretaceous and continued into the Paleogene.