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2 STRIDE JIP Phase III SUT Talk 15th November 2 Offshore VIV monitoring (vortex induced vibration) Catenary riser interaction with deepwater seabeds 3 Full Scale Riser Monitoring To get real measurements from installed risers Vortex induced vibration (VIV) response due to ocean currents Riser motions at the catenary touch down point (TDP) Full Scale Riser Monitoring - Allegheny 12 diameter simple catenary gas export riser Instrumented by 2H August loggers 33ft (15m) GoM, top 1/6 straked Atlantia Seastar mini TLP ADCP current data to 65m Distance Above Seabed (m) STRIDE JIP Phase II - Allegheny Riser Monitoring ALLEGHENY GAS EXPORT LINE MEAN INSTALLED POSITION TOP 8 DATA LOGGERS SPACED OVER 76FT BOTTOM 3 DATA LOGGERS SPACED OVER 12ft Strakes ADCP Loggers Allegheny - 2H ROV Retrievable Loggers Triaxial accelerometers 5g GRP holders Anti-fouling coating Logger ROV retrievable/installable No movement relative to riser Distance Along Seabed (m) Allegheny Gas Export SCR

3 Allegheny - Logging Details Logging commenced 19th August 2mins every 6 hours for 144 days. Local current monitoring from November 1999 Recorded data until 1th January hours of data collected by each logger. Allegheny Distance Above Seabed (m) Stride JIP Phase 3 - Allgeheny Riser Monitoring MEASURED CURRENT PROFILES Current Velocity (m/s) STRAKED UNSTRAKED Profile 1 Profile 2

4 SCR/Soil Interaction Harbour TDP Test Objectives GoM Spar SCR Trenching mechanisms, rates, geometries Vertical pull out Suction, stiction, hydro-pumping, peeling Hinge effect on pipe stresses and fatigue life Soil history, rate effects Lateral pull out Mechanism - roll-out, pull through Hinge effect Analysis benchmarking M.S.L. 1m 16m 11m SPAR 12 degrees Nominal Mud Line.m

5 Harbour Test Configuration Simulate GoM Spar in 1m 12 top angle at vessel, 7 at actuator 6-5/8 steel pipe, water filled 6.9 mm wall 113 m long 3.5 m tide 1m 2m Anchors SCR Actuator

6 1m 2m 1m 2m Anchors Anchors SCR SCR Actuator Actuator

7 13.5Te Swivel Hoist Ring 12Te Bolt Type Anchor 'Dee' Shackle (4 Off) 25mm Wire Rope 21Te Master Link 2Te Load Cell 13.5Te Swivel 12.7Te Turnbuckle Hoist Ring HG-228 Jaw & Jaw 1-3/4" x 24 In-plane and Out-of-plane Load Cell

8 Site Survey Soil characterisation done in advance Torvane surveys at each corridor Penetration tests Elevations with EDM Profile Plot 4 2 Height (m) Distance (m) Undeformed Profile Harbour Initial Nominal Profile Plot Height (m) M L K J I H G F E D C B A Accel Distance (m) Strain Gauges Initial Soil Profile Initial Nominal After Test Far

9 12 Vertical Isotropic Soil Shear Strength and Pipe Profile Ploted Against Distance from Anchor End of Pipe Vertical Isotropic Soil Shear Strength and Pipe Profile Ploted Against Distance from Anchor End of Pipe M K I G E C B A Height Above Mean Sea Level (m) M K I G E C B A Shear Strength (kpa) Height Above Mean Sea Level (m) Shear Strength (kpa) Distance from Anchor End of Pipe (m) Initial Soil Profile Initial Nominal Pipe Profile Far Pipe Profile Strain Guages Shear Strength at ½D Depth Shear Strength at 1D Depth Distance from Anchor End of Pipe (m) Initial Soil Profile Initial Nominal Pipe Profile Far Pipe Profile Strain Guages Shear Strength at ½D Depth Shear Strength at 1D Depth Shear Strength at 1.3D Depth A C D F J K M SOIL PROFILES STRIDE PHASE 2 - TDP Parametric Study SOIL SHEAR STRENGTH PROFILES. Undrained Shear Strength vs Depth Soil Strength (kpa) D.1.2 Depth Below Mudline (m) D 3D 4D 5D GoM Lower Bound GoM Typical West Africa West of Shetland 'Lower bound' to 'typical' range for deepwater Gulf of Mexico soils 'typical' to 'upper bound' range for deepwater Gulf of Mexico soils Shear Strength (KPa) Site Vane Strength Triaxial Strength (Lab) Fallcone (Lab) GoM Shear Strength Range Instrumentation Tension, shear Accelerometers Actuator position Riser bending 13 stations - vertical, horizontal 13.5Te Swivel Hoist Ring 12Te Bolt Type Anchor 'Dee' Shackle (4 Off) 25mm Wire Rope 21Te Master Link 2Te Load Cell 13.5Te Swivel 12.7Te Turnbuckle Hoist Ring HG-228 Jaw & Jaw 1-3/4" x 24 In-plane and Out-of-plane Load Cell

10 Harbour TDP Tests Actuator System PLC controlled sinusoidal actuation, user specified periods and amplitudes To 12 tonne tension 2.5 m linear stroke Separate horizontal and vertical actuation Far Nominal Near 1.4 m -.8 m Lateral Motion Displacment of Actuator Vs Time Actuator Displacment Vs Time Test »1s»21s Actuator Displacment (m) Actuator Displacment (m) 1..5.».1m/s ».1m/s Time (s) Time (s)

11 Test Log 15 logged tests waves - in plane, lateral, day to day, storm vessel drift - in plane, transverse, storm, failed mooring seabed and rigid surface high and low tide trench mechanisms, rates Soil Suction Compare lift up with lay down Compare seabed with rigid bed Bending Stress Lift Laydown Top vertical actuation Bend Time no suction Bend Time suction

12 Bend Time no suction Bending Stress Lift Laydown Bend Time suction Top vertical actuation Backfilled Trench Test

13 Rigid Surface Tests Lateral Pull Out Tests In Summary... Test objectives achieved? Lots of untapped data