27 November 2007

1. WP8 : D.8.1 Report on Deployment/Recovering Procedure 27 November 2007

2. Dome Design Limitations(as agreed during SENER meeting date 15/10/07) • 12 anchoring points (minimum weight in water 34OT, equipped with block and tackle) • Height of the cover: 50 m • Base diameter of the conic cover: 100 m • Upper diameter of the conic cover: 20 m (to be reduced and adapted to the DI final dimensions) • Mooring lines material: Mixte Vectran/Dyneema 80mm except for Dome boltrope and edge cable • Dome material : pre-tensioned membrane type FERRARI precontraint 1002 FLUOTOP T • Maximum vertical tension : 1000 T (minimum vertical tension into Sener early design)

3. DOME DESIGN

4. Deployment Procedure At this stage, 11 stages have been identified : Phase 1 – Deployment of the Mooring Anchorage Dead weights Phase 2 – Side Derrick and BBI installation Phase 3 – surface Deployment of the Dome and DI Phase 4 – Lowering the Riser Tubes along the guidelines Phase 5 – Surface Deployment of the Buffer Bell Phase 6 – Final upending of the Riser Phase 7 – Anchoring the Dome using Mooring Lines Phase 8–Tightening of the Mooring Lines Phase 9 – Deploying the Dome Phase 10 – Release of the riser assembly from the installation vessel Phase 11 – End of deployment procedure

5. Phase 1 – Deployment of the Mooring Anchorage Dead weights 9 off- simple deadweight installation 3 off - Dome installation aids deadweight installation

6. Phase 2 – Side Derrick and BBI installation

7. Phase 3 – surface Deployment of the Dome and DI • The Dome is installed on the deck of the Dockwise, the DI is fixed on a mechanical frame • Buoyancies are fixed on the DI and on the Dome bottom end side (upper part). A weight is fixed to the Dome bottom end side (lower part) • The DI/Dome assembly is over boarded from the transportation vessel with a crane

8. Phase 3 – surface Deployment of the Dome and DI • Removal of upper buoyancies, transfer and connection of the fix extremity of the three anchoring lines to the bottom part of the Dome, removal of the weight, resumption and setting of the tension in the anchoring lines at the specified tension

9. Phase 4 – Lowering the Riser Tubes along the guidelines • RTC assembled progressively on side derrick (50 m joints maximum) • Descent of the DI/Dome/RTC assembly controlled by winches • Tension controlled by the three tensioning lines

10. Phase 5 – Surface Deployment of the Buffer Bell

11. Phase 6 – Final upending of the Riser • the three supporting lines are release from the Buffer Bell • The Riser should slowly lower down to its operational depth, under control of the combined actions of the winches of upper tensioning line and Dome tensioning lines • Slack in the guide lines is taken away by the associated winches

12. Phase 7 – Anchoring the Dome using Mooring Lines • The moorings have already their mooring lines coiled and fixed onto them. The extremity of the mooring line is equipped with ROV hook and with a monkey fist, which is maintained into floatation a few meters above the seabed. • The ROV grabs the monkey fist and pull out the mooring line. • The ROV returns to the Dome, and connects the mooring line to the dome appropriate shackle with the ROV hook • The ROV repeats hooking operation with all of the mooring line, following a circular motion, until all of the mooring lines are connected to the dome

13. Phase 8–Tightening of the Mooring Lines • The ROV supervises the whole operation. • Before giving the order of releasing the soft lifting bags, the senior officer in charge of the project has to make sure that no unnecessary surface traffic is evolving within the firing area, and is outside a delimitated zone, to avoid the accidental surge of one or more lifting bags that would have been accidentally freed from their mooring lines. • ROV should be standing at a reasonable distance, and below the lifting bags trajectory, making sure its umbilical is not tangled with either the lifting devices or mooring lines. The best would be that it rests inside its hosting cage, away from any trouble. • Once the area is cleared, the order of firing is given, and transmitted via ultrasonic devices to the explosive units. • All of the lifting bags should be release at the same time.

14. Phase 9 – Deploying the Dome • The ROV supervises the whole operation. • ROV should be standing at a reasonable distance, outside the dome deployment area and below the lifting bags trajectory, making sure its umbilical is not tangled with either the lifting devices or mooring lines. The best would be that it rests inside its hosting cage, away from any trouble. • Once the area is cleared, the order of firing is given, and transmitted via ultrasonic devices to the explosive units. • All of the attachment devices of the dome should be release at the same time. • Visual inspection by the ROV of the entire dome assembly

15. Phase 10 – Release of the riser assembly from the installation vessel • The three tensioning lines and the two riser guide lines are locked onto the Buffer Bell buoyancy (or on the BBI) and the extra length is cut, leaving at least one meter of cable length below the cut for safety reason. • At the end of each cable, a conic blocking device should be set as an ultimate barrier against sliding away of the Buffer Bell.

16. BasinTests • Dome Cover deployment • for final mooring configuration • With all the mooring line • With one mooring line failed • For different current conditions • Riser/Dome behavior during deployment from surface • For different current conditions • For different tension conditions • Complete DIFIS system (Mooring +Dome+RTC+BB) behavior • For tension configuration of 1000T • For different current conditions