ABSTRACT

The Sunoco Felda oil trend of South Florida basin has been a prolific oil producer. All the oil is produced from the Cretaceous Sunniland formation, a leached limestone bioherm. Although the producing section has been considered reefal in the literature, petrographic and biostratigraphic analyses of various cores in producing fields have determined that these deposits are composed of particles of fragmented rudist and other fauna deposited in a tidal shoal. Atop this debris there has been deposited an algae and gastropod section, typical of a mound deposited on a tidal mudflat. This model is exemplified in the Sunoco Felda and West Sunoco fields and was used in exploration of the Sunoco Felda trend. From the petrological analysis of these two fields and from knowledge of other wells in the basin biostratigraphic and lithologic trends can be determined and extended offshore into the eastern Gulf of Mexico. The emphasis on petrology in the exploration of the Sunniland formation is stressed because correlation of like responses on electric logs do not always result in correlating the same depositional facies--in fact correlation of like electric log responses in the Sunniland formation often results in correlating different facies. This study endeavors to analyse the Felda trend based on the petrological and petrophysical information obtained from the cores and logs, and will show that the future potential of the Sunniland formation may be greater than that of the past and that this basin may be the site of future major discoveries.