Life Cycle Management for Gulf of Mexico Subsea Portfolio
Authors: Foster L.D. , Hebert P.B. , Nisbet W.J.R. , Sabatini D.E. , van Bellegem B. , Faucheux D.P. 
Published: October 2008

As subsea developments begin to make substantial bottom-line contributions, life cycle management becomes key to success. After installation and startup, a key measure of system performance is its ability to meet forecast production targets during its producing life. The Subsea Surveillance Team, together with the Asset Teams, within the Production and Surveillance arm of Shell Exploration and Production Company, are charged with ensuring that the production performance of the subsea systems is optimized: not just minimizing problems, but actively working to get the most out of each asset. The specific processes for accomplishing this objective, namely Asset Integrity, Flow Assurance and Maintenance Management, are described in this paper, both the near term "keep it working" efforts, and the longer-term, portfolio improvement drives.

Introduction

For Shell Exploration and Production Company (SEPCo), oil and gas production from the deep water Gulf of Mexico is playing an increasingly important role. Although most of the deep water production thus far has come from direct vertical access (DVA) wells (i.e., tension leg platforms, or TLPs), oil and gas quantities produced from subsea properties have become a significant portion of the total portfolio. Also, with the addition of the more recent subsea developments and the continual discovery of smaller reservoirs, the trend toward subsea development systems is believed to be an avenue for future growth in the Gulf of Mexico. Consequently, system reliability and uptime are crucial not only for existing subsea production, but also for new systems as design continues to expand beyond the boundaries of proven technology. For this reason, the implementation of an active subsea life cycle management process is critical for the continued success of SEPCo.

Life cycle management is comprised of three major processes: asset integrity, flow assurance, and maintenance management. Descriptions of these processes, and how they work to optimize Shell Exploration and Production Company's (SEPCo's) subsea production performance, form the basis of this paper.

Overview of life cycle management.

Management of a subsea development over its life cycle is a coordinated effort among several distinct groups within Shell, some residing in different companies. SEPCo, the operating company for Shell in the Gulf of Mexico, owns each producing asset and is accountable for its business performance. Multiple groups within SEPCo become actively involved in subsea projects once production begins, especially producing asset teams, surveillance teams, completion and intervention teams, and procurement support. All groups, but particularly the Major Projects Operations Team, to some extent direct their influence beyond the producing phase, toward managing the entire life cycle of each asset. Specific activities include:Early strategic planning with project teamsDevelopment of minimum functional requirementsMonitoring and remediating for optimum performanceBusiness forecastingAdjustments to strategy as development maturesContinuous knowledge transfer

Three distinct surveillance groups, as shown in Figure 1, are involved with life cycle management. The life cycle management processes described in this paper cover the portions of the subsea system listed under the subsea surveillance team (wellhead to boarding valve), and are linked to the processes covering other parts of the total producing system.