Summary This paper presents an overview of the Shell Offshore Inc. (SOI) Popeye project, a remote subsea gas development in 2,040 ft of water in the Gulf of Mexico (Refs. 1 through 4 contain additional technical details on the project). Planning and execution of the project required a balance throughout between proven methods, cost reduction, requirement for extending technology, and the desire to develop a system which could be used as a stepping stone to future deepwater prospects. Popeye was successfully installed and started up in January 1996. It represents application of an innovative, yet cost-effective, field development system that advanced the state of deepwater subsea technology.
Introduction In 1985, SOI discovered Popeye, a gas field in the Green Canyon area. A total of nine exploratory wells were drilled, and a four-block unit was approved in 1988. SOI is the operator and has a 37.5% interest. Partners include Mobil E&P Co. (12.5%), BP Exploration Inc. (12.5%), and CNG Producing Co. (37.5%), who purchased half of SOI's share and joined the other unit participants in 1992.
Joint subsurface and surface development studies were initiated in 1989, including consideration of a wide range of compliant structure, floating, and subsea options; processing options; and numbers of wells. With reserves smaller and riskier than originally anticipated, economic evaluations led to a focus by 1990 on satellite subsea development. Subsea feasibility and preliminary design studies addressed technical and cost issues over the next year. However, low product prices made even a subsea solution marginally economical.
SOI formed a Popeye subsea team in 1991 (the genesis of current subsea systems team) to tackle the dilemma of how to make Popeye an economically attractive development, while dealing with the severe application requirements of high-pressure, deepwater, and long-offset distance. An additional challenge was the desire to utilize technology which could be a springboard for many other, even deeper, SOI prospects.
The challenge was met and the development plan approved by the Popeye partners in March 1993. Key elements of the plan were phased development utilizing fewer high-rate wells, and smaller flowlines and topside facilities. Also, several innovations promised reduced costs and better economics over traditional subsea practices and represented necessary evolvement for the future. The Popeye project team was formed and the project successfully executed by January 1996. Despite difficulties which more than doubled the duration of planned drilling activities, the project was within original budget and only 3 months later than originally scheduled.