Suction Pile Installation Application Utilizing Predicted and
Real-time Monitored Suction Pressures
Yuan-Hung KuoMcDermott International, Inc.
1
Purposes
Offshore and Subsea Foundations
Suction Pile History and Needs
Challenges of Designing a Suction Pile
Conclusions
Contents
Browse the big picture of the offshore foundations
Introduce the history and the needs for Suction
Piles/Anchors
Discuss the challenges and risks of designing a suction
pilePurposes
Offshore and Subsea Foundations
Source: http://en.wikipedia.org/wiki/Oil_platform
Offshore and Subsea Foundations
Source:
http://www.internationalsubseaconsultantsllc.com/services
Offshore and Subsea Foundations
Concrete Gravity TypeMudmat
Driven PilesSource:
http://matdl.org/failurecases/File%253ASleipner_A_Tower.png.html;
http://www.offshore-technology.com/projects/hutton-field/hutton-field2.html;
http://www.oceanworks.com/our-business/oil-gas/subsea-chemical-storage-and-injection/
Suction Piles
Mooring/Holdback TypeFoundation Type
1950s and 1960s: Military equipment to fasten on the seabed and
release when necessary1970s: Shell develops the concept of suction
anchor.1981: Shell installed suction anchor in 40 m water for buoy
device.1990s: Mainly mooring suction piles have being installed in
water up to 1450 m.2000s: Subsea foundation suction piles have
being installed2010s: Heavy subsea modules emerged
Suction Pile HistorySource:
http://www.marinewellcontainment.com/may-2012-news/
Suction Pile Installation
Self Penetration DepthDesign Penetration DepthSuction
Penetration Range
Thin wall structure buckling failure controlledComplex of
offshore soil property sand/silt/claySoil and structure interaction
Geotechnical & Structural Engineering Boundary conditionsPile
handlingsSoil failure or structural failure
Challenges of Suction Pile design
Soil Plug Failure
Thin Shell Buckling Failure
Source: Google Images
Criticality of Suction Pile Design
Small D/t, Small L/DSmall D/t, Large L/DLarge D/t, Small
L/DLarge D/t, Large L/D
LDt = wall thickness
Suction Pile Design
Myth 2:Structural Buckling CurveStiff Soil Self Penetration
Depth Soft Soil Self Penetration Depth
Myth 1:Installation PressureSafety Factor
Myth Buster round 1 what the Real Suction Record tell us?
Pile Information:
Gulf of Mexico
Pile diameter 5.5 m
Pile length 22.9 m
Pile thickness 25.4 mm
Clay strength: 2.4 KPa to 38.8 KPa
Myth Buster round 1 Why the difference?
Flow Rate/Installation RealitySoil Uncertainty
Soil Static Friction
Soil Set-up
Installation practice
Real project to be installed this yearGulf of Mexico 1 Wall
Thickness20 Diameter X 100 LengthMyth Buster Round 2 What the code
check tell us?Where is the Safety Factor ??
API RP 2A
API Bulletin 2U
DnV RP C202
ABS Buckling Codes
Others
Eigen Analysis Approach
Material Nonlinearity
Imperfection Assumption
Boundary Conditions
Residual Stress
Soil Effect, Load Interaction, etc.FEA
ApproachesSemi-Experimental CodesMyth Buster round 2 Why the
difference?
Assuming 1.5 Wall ThicknessWhat shall be designed?
Myth 3 FEA Factor of Safety
Lb =20Lb =40Lb =60Lb =80Lb =100
Myth 4 Deformation limitation1.5 Wall Pile
The subsea development is limited by the foundation options
Suction pile foundation has both cost and capacity advantages
but has limitations
There are a few myths of design a suction pile in the
industry
Ignoring or being unaware of the myths could have huge financial
impact to a project
Conclusions
