Gannet E Subsea ESP: The Application of Technology in Practice

Abstract

Abstract The Gannet E single well subsea ESP development has been on stream since January 1998. This is the first such installation in the North Sea, and is only the third development of its kind in the world. At a 14km step-out from the Gannet Alpha platform, Gannet E represents a world record in terms of electrical transmission distance for such developments. Since start-up, flowrates of 18,000 barrels of oil per day have been sustained, whilst valuable operating experience has been acquired in a relatively short time span. During the project planning and execution phases, emphasis was placed upon anticipating potential operational pitfalls which 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 flowrates and required delivery pressures;Reservoir-related uncertainties;Well completion installation. The paper describes the technology and techniques applied in order to Maximise the safeguards to the overall system integrity and deliver a robust development. Actual start-up and running experience is discussed in relation to the planning effort. Attention is paid towards the analysis of trips and the evaluation of operability limits over the whole system. The major learning points which are being carried into further projects of this nature are also presented.