ZUO, HAIYIAN, Louisiana State University, Baton Rouge, LA

ABSTRACT: Structural and Hydrological Parameters Modeling of Wilcox Group, Central Louisiana and Mississippi

In a 900 sq mi area between Louisiana and Mississippi, 300 well logs were studied. Three major sand formations in middle Wilcox and five target log picks within upper and middle Wilcox were correlated. The lithofacies variation appear to be related to the sequence and eustatic boundaries. The temperature and salinity values modeled were also obtained from electric-log and BHT (bottom hole temperature) data. The relationships among the temperature and salinity distributions, topography, stratigraphy, and subsurface structure were studied. Several real images of three-dimensional topography, formation structure, and stratigraphic boundary were reconstructed by using the well log data.

This detailed study suggests that the productive oil fields along the east and west flank of Mississippi Embayment are related to the salinity anomalies, and are controlled by structural and stratigraphic features. From the three-dimensional maps, one can confidently interpret the structural and stratigraphic changes with time and basin growth history. For instance, it appears that the Holocene Mississippi River course in the study area is nearly coincident with the main depositional axis of middle and late Wilcox deposition. The current Mississippi River channel, as well as the basin's depositional axis of 20-50 m.y. ago, appear to have been affected by some regional structural events. Also, a north-south salinity anomaly in the east part of study area is a possible indicator of a no theast-trending wrench fault along the Mississippi River.

AAPG Search and Discovery Article #90989©1993 GCAGS and Gulf Coast SEPM 43rd Annual Meeting, Shreveport, Louisiana, October 20-22, 1993.