OTC 19547
All Electric Subsea Tree System
Vidar Sten-Halvorsen – FMC Technologies, Evind Koren - StatoilHydro
Copyright 2008, Offshore Technology Conference
This paper was prepared for presentation at the 2008 Offshore Technology Conference held in Houston, Texas, U.S.A., 5–8 May 2008.
This paper was selected for presentation by an OTC program committee following review of information contained in an abstract submitted by the author(s). Contents of the paper have not been
reviewed by the Offshore Technology Conference and are subject to correction by the author(s). The material does not necessarily reflect any position of the Offshore Technology Conference, its
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Abstract
This paper will present work that has been completed over the last several years to develop an all electric Subsea control
system ending with an all electric tree. The work is now conducted in a joint StatoilHydro-FMC Technologies R&D
program; Subsea MMX.
All electric systems provide CAPEX savings from reduced umbilical, OPEX savings from eliminating fluid consumption,
and environmental benefits from eliminating emissions of hydraulic fluids.
The basis system discussed in this paper is currently in use for Subsea Choke Control and Manifold Valve Control, and it
won the OTC Technology Award in 2006. This system is now further refined for application on safety critical applications
like Christmas Tree valves with improved redundancy and fault tolerance in order to meet requirements for safety and
availability.
This paper will discuss the analytical development and review of the safety critical electric tree system, as well as describe
the technical solutions developed. The development have taken into account the standardisation efforts by the Subsea
industry regarding control system interfaces and are compatible with the IWIS and SIIS RP standards.
Introduction
The Electric Tree system was derived from the already field proven All Electric System that so far have been controlling
choke and manifold valves on the StatoilHydro operated fields Statfjord and Norne.
Figure 1 – All Electric Tree