Gannet E Subsea ESP: The Application of Technology in Practice

Abstract

Summary The Gannet E single-well subsea electric submersible pump (ESP) development has been onstream since January 1998. This is the first such installation in the North Sea and only the third development of its kind in the world. At a 14-km step-out from the Gannet Alpha platform, Gannet E represents a world record in terms of electrical transmission distance for such developments. Since startup, flow rates of 18,000 barrels of oil per day (BOPD) have been sustained while valuable operating experience has been acquired in a relatively short time. During the project planning and execution phases, emphasis was placed on anticipating potential operational pitfalls that could jeopardize the overall success of the development. Areas of concern lay in the fields of ESP control and run life. Control of the platform facilities. Electrical power transmission. Data gathering. ESP flexibility with respect to flow rates and required delivery pressures. Reservoir-related uncertainties. Well completion installation. This paper describes the technology and techniques applied to maximize the safeguards in the overall system integrity and to deliver a robust development. Actual startup and running experience is discussed in relation to the planning effort. Attention is paid to trip analysis and evaluating operability limits over the whole system. Major learning points that are being carried into further projects of this nature are also presented.