Quantifying Spatial Depositional Patterns and Heterogeneity of Oolites within a Pleistocene Tidal-Bar Belt: An Analog for Carbonate Sand Reservoirs
Clint Barefoot, Jeffrey Byrnes, Michael Grammer, and James Puckette
Conditions were favorable during Mississippian time for significant deposits of oolitic carbonate sand to form in the continental United States. Oolitic deposits contain elevated interparticle porosity that often carries over to favorable petrophysical reservoir characteristics even after diagenetic processes. The objective of this research is to better understand oolitic depositional patterns in order to better understand ancient oolitic reservoir distributions. The lower Florida Keys provides a Pleistocene tidal-bar belt setting dominated by oolitic carbonate sands. The study area extends approximately 60 miles in length along the shelf strike direction with a range of approximately 8-20 miles of width perpendicular to strike. Tidal currents played a major role in shaping the oolitic depositional patterns in the lower Florida Keys. Tidal currents also appear to have influenced the depositional patterns of oolitic Mississippian reservoirs. By analyzing satellite images using ArcGIS software, we observe and quantify the spatial depositional patterns and heterogeneity of the oolitic sands in the lower Florida Keys. Although similar research has been conducted on active carbonate sand deposits in the Bahamas, studying and quantifying the lithified ooid deposits of the lower Florida Keys provides a more accurate analog for ancient ooid systems. The accumulation of these studies will provide an even greater understanding of the spatial distributions and heterogeneity within ancient reservoirs. This knowledge will be especially useful for reservoir modeling and planning for seismic acquisition. The favorable petrophysical characteristics often associated with oolitic reservoirs combined with increased exploration of Mississippian carbonates make understanding the spatial distribution and heterogeneity within these carbonate sands essential.
AAPG Search and Discovery Article #90176©AAPG Mid-Continent Meeting, Wichita, Kansas, October 12-15, 2013