The KOS 200 is FMC Kongsberg Subsea's (FKS) a new generation of Subsea Control System designed for current and future demanding control applications. The system is modular, using the state of the art high performance electronics, software based high speed modems and object orientated software-coupled with hydraulic and mechanical components with long field history.
The main objectives for the new generation of control system are to be able to control and monitor existing and future advanced subsea equipment producing significant amounts of data and demanding quick control actions. The subsea equipment being controlled may be at a long offset distance and deep water requiring reliable and efficient data communication, electrical and hydraulic power transfer. Interfacing to the topside control equipment is simplified by using standard Internet protocols, standardising the data format and pre-processing the sensor data.
The system has been developed in close w-operation with experts in Statoil and Shell and with vendors of Smart Well and processing equipment. The development has partly been funded by Statoil and Shell.
Tieback distances increases and topside facilities are replaced by subsea infrastructure for new fields being developed. The complexity of subsea instrumentation and the amount data produced subsea has increased dramatically the last years. This gives much more demanding requirements on data processing, communication, electrical and hydraulic power supply for Subsea Control. As an example. Figure 1 shows a field currently being studied. The subsea gas field will produce directly to shore and use a 170 km long composite umbilical. There is a high speed optical link to shore with an electrical back up communication system. In field there are both high speed electrical and optical communication. Three phase flow may be calculated using readings from subsea instrumentation combined with choke and flowline models.
In order to meet current and future requirement for Subsea Control FKS has developed a new generation Subsea Control System. The design is based on the experience from more than 250 wells being controlled by FKS equipment. A completely new generation of electronics is developed coupled with upgraded hydraulic and mechanical equipment. The description below will mainly focus on the electronic and software system.
The main blocks of the electronic system are depicted in Figure 2 The new generation Subsea Control Module (SCM) will communicate with the surface using optical fibre and/or a high speed data link on copper. The Topside Electronic Modules (TEM) communicate with the SCM and the HOST System Process Control Bus A PC with Smart Tool for Configuration and Diagnostic with connection to offshore for remote diagnostic and software updates is provided. The SCM and TEM have ample processing power and memory capacity for intelligent data and communication handling.
(The Figures is available in full paper)
The overall system electronic architecture is depicted in Figure 3. Two way communication links from the Subsea Electronic Module(SEM) to intelligent external sensors are Can Bus, ARS 485 serial lines or in case of Downhole sensor usually by proprietary communication and power links. For sample sensor the interface will be 4–20 mA or passive contacts. The SEM is dual redundant and external sensors are connected to both SEM's.