Integration of outcrop and subsurface data during the development of a naturally fractured Eocene carbonate reservoir at the East Ras Budran concession, Gulf of Suez, Egypt

Abstract

AbstractThe East Ras Budran Concession is located in the eastern rift shoulder of the Gulf of Suez. Syn- and pre-rift rocks are exposed in the north and east of the concession, and the Markha alluvial plain covers the SW. The Markha plain occupies the hanging wall of a large extensional fault which preserves most of the pre-rift stratigraphic sequence and >3500 m of syn-rift strata. Vertical wells drilled in 1999 indicated the presence of a >200 m oil column in low-porosity naturally fractured limestone beds of the Eocene Darat and Thebes formations. Outcrop, borehole image and core data define NW, WNW, N, NE, and ENE steeply dipping fracture sets. Borehole breakouts and drilling-induced fractures show that the minimum horizontal stress is aligned NNE to NE, so the NW and WNW fractures should be open in the subsurface. Using this structural picture, a near-horizontal well of 300 m length was drilled into the Darat in a NE direction. During testing, the well flowed at a rate of 1900 barrels of oil per day with no water. Future development of the field includes drilling similarly oriented wells with longer horizontal sections.