Oil exploration platforms can tap into deposits under the sea down to 3,500m deep. In shallow waters such as the Gulf of Mexico the platforms are firmly anchored to the sea bed. Oil exploration platforms suitable for the high seas must keep their position above the bore hole with engine power in spite of the wind and currents.

Their position is recorded by satellite with GPS and by sonar buoys on the sea bed. Their position is maintained by powerful electromotors on the four corners of the platform. These can revolve through 360 degrees. The highest demands are placed on the operational reliability of the dynamic position control because should the platform drift off there is the danger of great environmental damage and downtime.

The dynamic position maintenance control system and the associated field bus network must meet high real time and reliability requirements. Converteam opted for the FIP field bus protocol for the Transocean Sedco Forex express class platforms and networked the control components with Hirschmann's fiber optic cable repeaters. Converteam has designed a control system that meet the highest safety demands. As well as other safety precautions the control components are therefore designed with multiple redundancy and networked with fail safe fiber optic cables.

Project parameters

• positioning accuracy better than 5 m
• maximum ocean current 3,5 knots
• maximum wind speed 60 knots
• maxim um wave height 9 m
• installed engine rating 4 * 7 MW
• maximum water depth 3500 m

Solution

• complete optical networking
• World FIP field bus system
• four hierarchically structured field bus rings
• dual design, multiple meshed ring in dynamic positioning system
• constant status monitoring in dual monitor systems
• 40 OZD FIP G3 T LWL repeaters per platform
• LWL cabel with multimode 62,5 / 125µm fibers
• maxim um cable length 300 m