To control Subsea fields in remote and challenging environments such as the artic, a large amount of system information combined with high availability are key features for a Controls system to succeed. Trying to use traditional power and communication methods, will not meet these requirements, and new ways (robust and versatile) are required.
The paper will describe how to addresses these challenges discussing high speed communication and intelligent power distribution networks. Available field history will be discussed to provide feedback.
High speed communication using fibre optic with or without local copper lines is becoming more and more the standard for subsea communication networks. The available high bandwidth feature provides the large amount of data required to control fields with complex architectures. Combining this with open communication architecture and the appropriate subsea local area network gives third parties direct access to their IP enabled devices, to monitor and actively perform data uploads. This concept is in use as a world wide first application since June 2008 on the BP Taurt Project of the coast of Egypt in the Mediterranean Sea. Further expansion of this field as well application on other projects proves the viability of this concept.
Redundant controlled power distribution (on an AC or DC basis) will provide the functionality to control power distribution to the Subsea Control Modules (SCM). This feature will allow power control to the SCMs on an individual basis. Various scenarios not possible before can now be done:
Extension of an existing field whilst the originally installed field can remain in full operation.
Installation and retrieval of an individual SCM without interference of the overall field by swapping the power be fore the Electrical Flying Lead (EFL) disconnect takes place.
This feature will also open the possibility to actively monitor the subsea voltages and currents. This information can be used to early detect any abnormal power consumption and confirm the health status of the subsea controls equipment, and provides benefits on overall system reliability/availability required in challenging operating environments such as the artic.