Work Package 5 Early Design DIFIS Project Meeting May 29-30 2006

1. Work Package 5 Early Design DIFIS Project Meeting May 29-30 2006

2. Content • Progress and planning • Functional requirements • Design requirements • Material specifications • Proposed alternatives for preliminary design • Preliminary calculations/dimension elements • Buffer Bell • Riser Tube • Dome • Anchors • Connections • Construction phases

3. Progress and planning WP5 – Early Design Start: May 2006 -Proposition of alternatives -Initial calculations Buffer Bell End: October 2006 Actual status: waiting for input data WP2 / WP3 and functional requirements WP4

4. Functional requirements

5. Functional requirements

6. Design requirements

7. Material specifications

8. Proposed alternatives for preliminary design Buffer Bell (3) Riser Tube / Mooring lines (3) DIFIS System - Water depth - Storage capacity - Pre-tension Dome (3) Anchors (3) Connections (0)

9. DIFIS System

10. Buffer Bell Global dimensions configurations: Oil recovery buffer 1250 m3 (1000 ton, oil density 0.8 t/m3) Floating chamber (Air) 1100 m3 Upward force 1000 ton, Bell filled with water 1300 ton, Bell filled with oil (0.8 kg/m3)

11. 12,5 m 17,5 m 10,0 m 15,0 m Air Air Oil/Water Oil/Water 10 m Air Air 20 m Water 2,0 m Water 2,0 m Buffer Bell Configuration A Configuration B

12. Buffer Bell Extreme condition: water depth 200 m water pressure 2000 kN/m2 External forces? Floating Chambers? Connection points?

13. Buffer Bell, conceptual calculations

14. Riser Tube Ring 2 m Riser Tube without mooring lines Riser tube takes the structural loads

15. Mooring Line Mooring Line Mooring Line Mooring Line Riser Tube Riser Tube Ring Ring 2 m 2 m Riser Tube with mooring lines Riser tube inside mooring lines Riser tube outside mooring lines

16. Dome Alternatives Structural loads in Dome Structural loads in Mooring lines, Dome resting on mooring lines Central mooring lines and anchor, seperate mooring Dome

17. Anchors • Clay and unconsolidated sand • Vertical load anchors VLA • Suction Anchors • Hard soil and rock • Drag embedded anchors • Mechanical fitting on hull of the ship • Pyrotechnic • Drilling • Magnetic devices

18. Connections ?

19. Construction phases, WP.4.2 DIFIS deployment proposal sequence • Installing anchors • Assembling on board, riser and dome folded • Lowering whole system, Buffer Bell / Folded riser and Dome • The buoyancy of the Buffer Bell and the whole system is nullified • Controlled lowering velocity • Connecting mooring lines to anchoring points by ROV´s • Removal of ballast, unfolding the riser due to buoyancy of the Buffer Bell • ROV´s unfold the dome and secure it in designed dimensions DIFIS retrieval proposal sequence • Pyrotechnic cutters cut the mooring lines • Buffer Bell surfaces along with the dome and riser and is retrieved by surface vessels • Removal of anchors by the anchor operator Consequence: Buffer Bell design for water depth of 4000m (water pressure 40000kN/m2) Consequence: Functional requirement, Buffer Bell with ballast tanks Consequence: Folding capacity of mooring lines

20. Construction phases, Alt 1 DIFIS deployment proposal sequence • Installing anchors • Connecting mooring lines to anchors • Lowering ring over mooring lines to form Dome form • Lowering geotextile dome and connection to mooring lines and ring • Lowering geotextile riser tube over the mooring lines • Connecting Buffer Bell to mooring lines and introducing pre tension in system DIFIS retrieval proposal sequence • Pyrotechnic cutters cut the mooring lines • Buffer Bell surfaces along with the dome and riser and is retrieved by surface vessels • Removal of anchors by the anchor operator Consequence: Risk of oil spill during retrieval of system