The Endicott Field is the first Arctic offshore producing oil field. Early reservoir studies showed that optimum recovery would require start-up of waterflooding within the first two years of production. This paper describes the engineering and geological work done to implement and optimize the Endicott Field waterflood.
The reservoir at Endicott Field is contained within the Mississippian Kekiktuk Formation. These multistory fluvial sandstones are characterized by wide variations in rock properties. Thick areally extensive shales combined with sealing intra-reservoir faults, serve to subdivide the field into seven distinct reservoir management sub-zones.
The design and implementation of this waterflood project extensively used simulation studies. These studies showed that waterflooding would nearly double the recovery and there were significant benefits for returning the field to original pressure. Simulation models optimized both the number and placement of production and injection wells.
The first production facility sealift included waterflood facilities. This enabled a pilot program to be implemented within five months after production start-up to shake down facilities, determine well injectivity and obtain early waterflood performance data.