Asset Integrity Management for Offshore and Onshore Structures

Front Cover
Asset Integrity Management for Offshore and Onshore Structures
Copyright
Dedication
Contents
About the author
Preface
Chapter 1: Corrosion effects on offshore and onshore structures
	1.1. Introduction
	1.2. Corrosion effects on offshore structure
		1.2.1. Corrosion in seawater
		1.2.2. Steel corrosion in seawater
	1.3. Pipelines
	1.4. Onshore structure
		1.4.1. Black corrosion
		1.4.2. Pit formation
		1.4.3. Reasons for steel-in-concrete corrosion
			1.4.3.1. Carbonation
				Carbonation propagation rate
			1.4.3.2. Chloride attack
				Chloride propagation
		1.4.4. Corrosion rates
		1.4.5. Corrosion's effect on spalling of concrete cover
		1.4.6. Bond strength between concrete and corroded steel bars
		1.4.7. Influence steel bar corrosion on the shear strength
	References
Chapter 2: Integrity management versus reliability
	2.1. Introduction
	2.2. Principle of reliability
		2.2.1. Structure reliability calculation
			2.2.1.1. Reliability analysis using first- and second-order methods
		2.2.2. Probability in limit states design
			2.2.2.1. Equivalent normal distribution
			2.2.2.2. Procedure for reliability analysis
			2.2.2.3. Reliability index calculation for different codes
			2.2.2.4. Monte Carlo simulation technique
		2.2.3. Load variables
		2.2.4. Structure resistance variables
		2.2.5. Concrete strength variations
		2.2.6. Steel yield strength variable
		2.2.7. The nonbasic variables in design
	2.3. Concrete cross-section variation
		2.3.1. Uncertainty in steel bars during construction
		2.3.2. Variability in the steel size
		2.3.3. Reliability approach in EC2 code
			2.3.3.1. Design values calibration
			2.3.3.2. Reliability verification formats in Eurocodes
				Consequences classes
			2.3.3.3. Engineering design quality in EC
			2.3.3.4. Execution quality in EC
	2.4. Pipeline reliability analysis
		2.4.1. Limit state equation for the pipeline
		2.4.2. Reliability model
		2.4.3. Determination of corrosion rate
	2.5. Offshore structure reliability
	2.6. FPSO integrity
	References
Chapter 3: Inspection techniques
	3.1. Introduction
	3.2. Offshore structures
		3.2.1. Flooded member inspection
		3.2.2. Magnetic particle test
		3.2.3. The inspection report
		3.2.4. Topside inspection
		3.2.5. Offshore structure inspection plan based on ISO
	3.3. Piping and pipeline inspection
	3.4. Inspection methods
	3.5. Tank inspections
		3.5.1. Settlement survey
	3.6. Onshore structures
		3.6.1. Steel structures
		3.6.2. Concrete structures
			3.6.2.1. Concrete strength NDT
				Core test
				Rebound (Schmidt) Hammer test
				Ultrasonic test
		3.6.3. General test methods comparison
			3.6.3.1. Steel in concrete corrosion measurement test
				Chloride content penetration
				Concrete cover measurements
				Carbonation depth measurement
				Chlorides test
				Half-cell
	References
Chapter 4: Assessment of structures and pipelines
	4.1. Introduction
	4.2. Assessment for onshore concrete structures
	4.3. Concrete structure probability of failure
		4.3.1. Concrete strength with age
			4.3.1.1. Concrete strength with age in different codes
			4.3.1.2. Variation in concrete strength
		4.3.2. Variability of the concrete strength in a member
		4.3.3. Corrosion of steel and concrete deterioration
		4.3.4. Statistical data for corrosion rates
		4.3.5. Capacity loss in reinforced concrete member
		4.3.6. Effect of age and steel ratio
		4.3.7. Start time of corrosion
		4.3.8. Column eccentricity effect on reliability
	4.4. Design and maintenance recommendations
	4.5. Pipeline assessment
	4.6. Storage tank assessment
	4.7. Assessment for onshore steel structure
	4.8. Assessment of offshore structure
		4.8.1. Non-linear structure analysis in ultimate strength design
			4.8.1.1. General purpose non-linear beam column models
			4.8.1.2. Plastic hinge beam column models
			4.8.1.3. Phenomenological models
			4.8.1.4. Shell FE models
			4.8.1.5. Modeling the element
			4.8.1.6. Conductor connectivity
		4.8.2. Structural modeling
			4.8.2.1. Secondary framework
			4.8.2.2. Dented beam and cracked joint
		4.8.3. Determine probability of structural failure
		4.8.4. Establish acceptance criteria
			4.8.4.1. Topside assessment
	4.9. Assessment for FPSO
	References
	Further reading
Chapter 5: Repair methods for offshore and onshore structures
	5.1. Offshore structures repair
		5.1.1. Jacket repair
		5.1.2. Dry welding
		5.1.3. Dry welding on topsides
		5.1.4. Dry welding at or below sea surface
		5.1.5. Hyperbaric welding
		5.1.6. Platform underwater repair
		5.1.7. Platform ``shear pups´´ repair
		5.1.8. Underwater repair for platform structure
		5.1.9. Case study 2: Platform underwater repair
		5.1.10. Clamps
		5.1.11. Stressed mechanical clamps
		5.1.12. Unstressed grouted clamp connections
		5.1.13. Stressed grouted clamps
		5.1.14. Stressed elastomer-lined clamp
		5.1.15. Drilling platform stabilization post-hurricane Lili
		5.1.16. Grouting
			5.1.16.1. Joint grouting
			5.1.16.2. Grout filling of members
			5.1.16.3. Allowable axial force calculation
		5.1.17. Composite technology
			5.1.17.1. Reinforced epoxy grout
			5.1.17.2. FRP composites
		5.1.18. Example of using FRP
		5.1.19. Case study for conductor composite repair
		5.1.20. Fiberglass access decks
		5.1.21. Fiberglass mudmats
	5.2. FPSO repair
	5.3. Pipeline repairs
	5.4. Onshore structures
		5.4.1. Main steps to execute repair
		5.4.2. Structure strengthening
		5.4.3. Demolish the delaminated concrete
		5.4.4. Clean concrete surface and steel reinforcement
		5.4.5. Bond new concrete with old concrete
		5.4.6. Clean steel reinforcement bars
		5.4.7. New concrete properties
		5.4.8. Tank ring beam repair
		5.4.9. Objective of strengthening concrete members
		5.4.10. Slab on grade repair
		5.4.11. Strengthening concrete by steel sections
		5.4.12. Fiber reinforced polymer (FRP)
			5.4.12.1. Carbon fiber reinforced polymer (CFRP)
			5.4.12.2. Application on-site
			5.4.12.3. General precautions
	References
	Further reading
Chapter 6: Proactive approach to integrity
	6.1. Introduction
	6.2. Onshore structure protection
		6.2.1. Corrosion inhibitor
		6.2.2. Anodic inhibitors
		6.2.3. Cathodic inhibitor
		6.2.4. Coating of steel bars by epoxy
		6.2.5. Galvanized steel bars
		6.2.6. Stainless steel
		6.2.7. Fiber reinforcement bars
		6.2.8. Protecting the concrete surface
			6.2.8.1. Sealers and membranes
				Coating and sealers
				Pore lining
				Pore blocking
		6.2.9. Cathodic protection system
			6.2.9.1. CP components and design considerations
				Source of impressed current
				Anodes for columns, beam, and foundations
				Conductive layer
		6.2.10. Comparison between cathodic protection and others
	6.3. Offshore structure protection
		6.3.1. Geometric shape
	6.4. Steel structure coatings and corrosion protection
	6.5. Corrosion stresses due to the atmosphere, water, and soil
		6.5.1. Classification of environments
			6.5.1.1. Categories for water and soil
		6.5.2. Mechanical, temperature, and combined stresses
	6.6. General CP design considerations
		6.6.1. Environmental parameters affecting CP
		6.6.2. Design criteria
		6.6.3. Protective potentials
		6.6.4. Detrimental effects of CP
		6.6.5. Galvanic anode materials
		6.6.6. CP design parameters
			6.6.6.1. Design life
			6.6.6.2. Design current densities
			6.6.6.3. Coating breakdown factors for CP design
			6.6.6.4. Galvanic anode material design parameters
			6.6.6.5. Anode resistance formulas
			6.6.6.6. Seawater and sediment resistivity
			6.6.6.7. Anode utilization factor
			6.6.6.8. Current drain design parameters
		6.6.7. CP calculation and design procedures
			6.6.7.1. Current demand calculations
			6.6.7.2. Selection of anode type
			6.6.7.3. Anode mass calculations
			6.6.7.4. Calculation of anodes number
			6.6.7.5. Calculation of anode resistance
			6.6.7.6. Anode design precaution
			6.6.7.7. Distribution of anodes
	6.7. Design example
	6.8. General design considerations
	6.9. Anode manufacture
	6.10. Installation of anodes
	6.11. Anode dimension tolerance
		6.11.1. Internal and external inspection
			6.11.1.1. FPSO protection
			6.11.1.2. Pipelines and tanks
				Pipeline internal coating
			6.11.1.3. External coatings
				Storage tank protection
	References
	Further reading
Chapter 7: Integrity management system
	7.1. Introduction
	7.2. Offshore structure integrity management (SIM) system
		7.2.1. Structure integrity management (SIM)
		7.2.2. Qualitative risk assessment for platforms
		7.2.3. Likelihood of failure factors
			7.2.3.1. Likelihood of failure calculation
				Strength factors
					Design codes
					Number of legs and bracing system
					Piles system
					Risers and conductors
					Boat landings
					Grouted piles
					Damaged, missing, and cut members
					Splash zone corrosion and damage
					Flooded members
					Cathodic protection and anode depletion
					Inspection history
					Remaining wall thickness
				Loads factors
					Design loading
					Marine growth
					Scour
					Topside load change
					Risers, caissons, and conductors factor
					Wave in platform deck
					Seismic load
			7.2.3.2. Likelihood categories
		7.2.4. Impact or consequence factors
			7.2.4.1. Environmental impact losses
			7.2.4.2. Impact on business losses
			7.2.4.3. Safety impact loss
			7.2.4.4. Consequence categories
		7.2.5. Overall risk ranking
	7.3. Risk assessment outcomes
		7.3.1. Cathodic protection
		7.3.2. FPSO risk-based inspection
		7.3.3. Strategy of inspection and repair
			7.3.3.1. Expected Total cost
			7.3.3.2. Optimization strategy
			7.3.3.3. Onshore facilities and structure integrity
	References
	Further reading
Index
Back Cover