Challenges and Decisions in Developing Multiple Deepwater Fields
Authors: Thurmond B.F. , Walker D.B. , Banon H.H. , Luberski A.B. , Jones M.W. , Peters R.R. 
Published: October 2008

Abstract
Beginning in 1999, BP and its co-lessees embarked on an ambitious program to develop four major fields in deepwater regions of the Gulf of Mexico. Along with presenting a brief summary of each development's unique features, this paper describes the primary challenges facing BP's management in planning and executing this string of major projects and the associated pipeline transportation system project. Contracting approaches and associated issues such as standardization are discussed, along with constraints imposed by service industry limitations and available human resources. BP's approach to technology selection and technology development, in light of limited industry experience and specific Gulf of Mexico environment challenges, are also addressed.

Introduction
The hydrocarbon potential of the deepwater Gulf of Mexico has been known by the industry for over two decades. Widescale development began in the nineties, most visibly through the deployment of a series of TLPs by Shell in water depths of 3000-4000 feet. Field development in water depths beyond 4000 feet began in earnest around the year 2000, perhaps highlighted by four major projects led by BP: Holstein (with co-lessee Shell), Mad Dog (with co-lessees BHP Billiton and Unocal), Thunder Horse (with co-lessee ExxonMobil), and Atlantis (with co-lessee BHP Billiton). The schedules for these four projects are sequential but largely overlapping, with the first installation targeted for 2004 and the last one scheduled for 2006. All four projects will export oil and gas through the Mardi Gras transportation system, also operated by BP and, itself, a major project. Importantly, with each complex constituting a "hub" and operating for a nominal period of twenty-five years, there will be opportunities for BP and its co-lessees to further utilize the infrastructure by tying in other discoveries to maintain or increase production levels.
The overall program has required a coordinated yet flexible approach to contracting and resources. Technology selection and development has been a major challenge in view of the water depths, environment issues, and reservoir conditions. None of the projects can be categorized as "business as usual," with each having an impressive list of unique features and industry firsts.

Overview of the Developments
The Holstein, Mad Dog, and Atlantis fields are in the Southern Green Canyon area with hub locations in water depths of 4344, 4420, and 7100 feet respectively. The Thunder Horse field is located in the Mississippi Canyon area with its hub facility located in a water depth of 6300 feet. Two basic development concepts were ultimately chosen for the overall program, the truss Spar and the semi-submersible, as depicted in Figure 1. Holstein and Mad Dog are truss Spars while Thunder Horse and Atlantis are semi-submersibles.
Figure 2 provides a visual comparison of the water depths. Approximate start-up dates are also indicated. The installation sequence is as follows: Mad Dog, Holstein, Thunder Horse, and Atlantis. For completeness, three existing deepwater hubs operated by BP in Gulf of Mexico deepwater are included in Figure 2: Marlin, Horn Mountain, and Na Kika.
To briefly describe these three existing hubs, the host facility at Marlin is a TLP, which has been operating since 1999. Horn Mountain is a truss Spar, which was installed and began production in 2002. Na Kika is a semi-submersiblebased development where BP, as prescribed in the field's Joint Operating Agreement, began its role as post-production Operator upon start-up late in 2003. Prior to start-up, Shell, BP's co-lessee in the development, served as the preproduction Operator. Shell was responsible for design, constructi