Joint development of Diana and Hoover is allowing the economic development of an estimated 300MMBOE over 100 miles from existing facilities in 4800' water depths. The two fields have different structural styles, fluids types, and reservoir architectures. Diana is a subsea development tied back to a Deep Draft Caisson Vessel (DDCV) host at Hoover. First production began in May 2000.
Diana consists of a large gas cap and thin oil rim trapped by a stratigraphic pinchout of the Plio-Pleistocene A-50 turbidite sand onlapping a salt-cored high. Average gross thickness is ~80'. Reservoir quality and thickness degrade from north (proximal) to south (medial/distal). Diana phase one utilizes five horizontal wells for oil rim depletion, phase two will develop the gas cap. Horizontal wells provide high deliverabilty and optimally deplete the oil rim with a minimum number of wells. These wells mitigate coning with low overall drawdown spread out over a large area, thereby delaying water breakthrough. The wells are placed high in the 250' oil column to maximize OWC standoff, and cut the entire highly stratified A-50 sand to contact all internal flow units.
Hoover is an undersaturated oil reservoir in the Pliocene P1:10 sand anticlinally trapped over a diapiric shale ridge. The reservoir is a high net-to-gross channelized turbidite near the basin sediment entry point. Bottom-water is present under two thirds of the field. Gross reservoir thickness ranges from 140' to thin/absent on the structure's crest. A mixed portfolio of conventional and horizontal wells are being drilled from the DDCV.