Jack and St. Malo, USGOM: Similarities and Differences in Two Co-Developed Deepwater Wilcox Fields

Abstract

The Jack and St. Malo fields, located 25 miles apart in the outboard Walker Ridge area of the deepwater Gulf of Mexico, share similarities in water depth, stratigraphy, structural style, reservoir depth, pressure, thickness, and rock and fluid properties. Production from both fields began in December 2014, with encouraging results to date. The long list of similarities allowed each field to benefit from geologic, engineering, and operational learnings at its nearest analog as the two structures were co-developed. Due mainly to geologic differences between the fields, the development outlook and key questions to be answered for each are distinct. St. Malo has a downdip penetration (deepening of the Dana Point Miocene exploratory well) that constrains oil-water contact uncertainty, whereas Jack lacks well control off the structural crest. Though the total number of seismically imaged faults in the two fields is not significantly different, the arrangement is such that Jack is more compartmentalized, requiring more extensive appraisal. Conversely, St. Malo has a large, pressure connected main fault block to underpin a significant primary development with potential enhanced recovery opportunities. The development is still in its infancy with many questions remaining. Will waterflood or other EOR techniques succeed at St. Malo? Will Jack prove to have a large connected volume, or remain in extended appraisal mode? How much depletion stress can the reservoir handle? Building on the first dozen years of learnings, the next ten years at JSM will be key to estimating the development potential of other deepwater Wilcox fields.

AAPG Datapages/Search and Discovery Article #90291 ©2017 AAPG Annual Convention and Exhibition, Houston, Texas, April 2-5, 2017