This paper is based on the work performed during the design, implementation and operation of Cascade and Chinook fields and it provides an overview of the Cascade and Chinook fields' reservoirs, part of the emerging Ultra-Deepwater Wilcox Trend in the Gulf of Mexico. A general picture of the structure, stratigraphy, depositional facies, and petrophysics of each field will be given. Reservoir engineering parameters will also be discussed as well as the initial field development. The main result of this work is a consistent integration of all available data, following a recommended workflow process, aiming to build a geologically coherent and realistic reservoir models for these fields. The match of real field production information with the dynamic flow models allows the reduction of uncertainties of the scenarios and better support for the production forecast. From the integration of seismic, logs, fluids, cores and production data has emerged structural models similar for both fields: a faulted salt-cored anticline divided roughly into western upthrown and eastern downthrown blocks, populated with amalgamated-to-stacked turbidite sands. The petrophysical model developed considers the geologic background and supports the dynamic flow model. The main technical contribution of the work presented in this paper is an overview of the reservoirs that have pioneering production from the Lower Tertiary (Wilcox) Ultra-Deepwater trend (Walker Ridge area). These fields are the first analogues for a mostly untested trend which is still projected to have significant production potential. Currently, numerous oil & gas companies have several Wilcox fields, prospects, and plays in varying stages of development in the area. The information provided and the modeling approach used in this paper can be applied as guidelines for similar Lower Tertiary reservoirs developments in the deepwater Gulf of Mexico.

No abstract

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.