The Lower Tertiary (LT) play is the most recent production frontier in the deepwater of the Gulf of Mexico (GoM) in the United States. All LT discoveries in the area share common characteristics: deep reservoirs with low permeability, thick pay section, high initial reservoir pressures, Ultra-Deepwater depths, and long distances from flowline tie-ins. The Cascade field started producing in 2012 and has succeeded in proving the feasibility of the LT play as a new GoM producing horizon.
The Cascade Field is located in the GoM at 250 miles South of New Orleans, Louisiana and 165 miles from the closest position on the Louisiana coast. Its wells are placed at 8,200 ft. water depth in the Walker Ridge area. The LT reservoirs (Wilcox Fm.) are composed of many sandstone layers extending vertically for approximately 1,000 ft.
This paper will describe technologies applied in LT projects to deal with reservoir characterization and management, well construction, and production operations as a case history. Some of the topics addressed in this paper include: fracture design optimization, well completion design, pressure history, skin analysis, reservoir characterization, and technical limitation on production drawdown, artificial lift, and their impact on the formations.
The current low oil price market forces operators to become more efficient and creative in reducing the overall capital expenditure to develop the LT play. This paper will suggest potential future enhancements in well design to make the wells more efficient and improve project economics.