Refining Well Log Correlation in the Greater Enchilada Area, "Mexican Buffet Region," NE Garden Banks, Gulf of Mexico, Using High-Resolution Nannoplankton Biostratigraphy

Abstract

In the Mexican Buffet Region most of the pay sands are subsalt, which complicates and reduces the resolution of seismic surveys. This makes it necessary to look for other methods to make correlations of pay sands between wells. Using nannofossil data collected since the discovery well was drilled in 1994 from Enchilada, Chimichanga, and Salsa, a way has been developed to identify nannofossil field markers. This method was tested in three wells in Enchilada, Garden Banks 128, in the NP 2.9 objective zone and agreed well with the foraminiferal field markers and seismic correlations. Subsequently this method was used to identify and correlate a nannofossil field marker in the NP 3 zone of Chimichanga (Garden Banks 127), Enchilada (Garden Banks 128), and Salsa (Garden Banks 172). This field marker, used in conjunction with a foraminiferal field marker in the same section, provided a new correlation scheme for the P 3 pay sands previously thought to be discontinuous stringers. This correlation indicates that the sands are continuous through the Enchilada and Chimichanga fields. This pay interval is now thought to contain a significant amount of oil reserves.