Читать книгу Underwater Inspection and Repair for Offshore Structures - Gerhard Ersdal - Страница 4

1 Chapter 1Figure 1 The elements of why we inspect structures.Figure 2 Damage to hull structural members by different causes and ship age ...Figure 3 Typical bathtub curve. It should be noted that ageing may set in ea...Figure 4 Examples of types of offshore structures: (a) is a jack‐up placed a...Figure 5 Various forms of wind turbine substructures: (a) suction pile caiss...Figure 6 The management process for safe operation by inspection and mitigat...

2 Chapter 2Figure 7 Elements of Structural integrity management, based on HSE (2009)....Figure 8 Main SIM process of API RP 2SIM (API 2014b) and follow‐on steps....Figure 9 Structural integrity management cycle (surveillance includes inspec...Figure 10 An example of a typical SIM process based on a major hazard approa...

3 Chapter 3Figure 11 Examples of damage cause (why the damage occurs), types (what they...Figure 12 Aluminium anode recovered from West Sole WE platform showing less ...Figure 13 Dented member.Figure 14 Illustration of location of damage to platform A in Table 6.Figure 15 Frequency of damage types.Figure 16 Frequency of causes of damage.Figure 17 Cause and frequency of damage to fixed offshore structures.Figure 18 Reported defects by category.Figure 19 Gulf of Mexico platform leaning damaged in a hurricane.Figure 20 Pancake leg damage—fully severed leg and initial damage configurat...Figure 21 Mooring line elements and typical damage zones.Figure 22 Partially loose stud, from corrosion or mechanical damage (HSE 201...Figure 23 General corrosion on a recovered floating production unit mooring ...Figure 24 Example of moderately severe corrosion in wire rope (HSE 2006)....Figure 25 Rope in Figure 23 after thorough cleaning (HSE 2006).Figure 26 Example of moderately severe external wear in wire rope (HSE 2006)...Figure 27 Load regimes for a studded link showing failure locations, termino...Figure 28 Fatigue damage at the crown of a non‐studded chain (HSE 2017a)....

4 Chapter 4Figure 29 Dent depth and associated bows and cracks.Figure 30 Bows with associated dents and cracks.Figure 31 Relationship between the different NDE techniques versus cost and ...Figure 32 Ability to detect a crack in member for different NDE techniques....Figure 33 Bureau Veritas minimum requirements for type approval, based on cr...Figure 34 Tongue Sands Tower.Figure 35 Chloride levels from cores taken from the Tongue Sands Tower vs he...Figure 36 Ultrasonic testing both for thickness and detection of internal fl...Figure 37 Magnetic particle method illustrated.Figure 38 Count rates for different examples of flooding under water.Figure 39 Methods of potential mapping (Department of Energy 1987b).Figure 40 Examples of anode condition, approximately 20% to 90% usage.Figure 41 ROV being deployed.Figure 42 ROV installation of Robotised Inspection Tool.Figure 43 RIT: Robotised inspection tool.Figure 44 Two examples of AUVs.Figure 45 Rail installation (Vertical Access Tool) of Robotised Inspection T...Figure 46 Seven CMM processes for maturity model for managing structural int...Figure 47 PoD curves for different NDT inspection methods based on DNVGL RP‐...Figure 48 PoD curves CVI inspection for two levels of access difficulty base...Figure 49 Two examples of inspection of concrete structures underwater. The ...

5 Chapter 5Figure 50 West Sole WE platform.Figure 51 Typical fixed steel platform response spectrum.Figure 52 Effects of member severance on NS natural frequency.Figure 53 Change in natural frequencies at, for example, a member failure....

6 Chapter 6Figure 54 Transition from the as‐built to the as‐is condition of the structu...Figure 55 Approaches to planning offshore structural underwater inspections....Figure 56 Example of risk matrix for risk‐based inspection planning. L indic...Figure 57 Structural integrity data management system with examples of conte...Figure 58 Inspection intervals in years for a sample structure (PSA 2007).Figure 59 Inspection intervals in years up to 50 years for varying RIF value...Figure 60 The RBI process, based on EI (2020).

7 Chapter 7Figure 61 Overall evaluation and assessment approach.Figure 62 Database of surface crack development in tubular joint fatigue tes...Figure 63 Prediction of number of joints with significant cracks.Figure 64 Limited life between N₃ and N₄ for a typical joint test (Sharp et ...Figure 65 Distribution of N₄/N₃ ratios for 277 different tubular joints.Figure 66 Tubular joint with large degree of cracking.Figure 67 Fatigue test results including N₂, N₃ and N₄ measured cycles.Figure 68 Results of experimental tests on ultimate strength of cracked tubu...Figure 69 Wave height at system failure with increasing number of component ...Figure 70 Model of patch corroded tubular member.Figure 71 Patch corrosion profiles: (a) cut‐off, (b) rounded and (c) sinusoi...Figure 72 Experimental results of patch corroded tubulars.Figure 73 Q‐Q plot comparing experimental and FEA capacities of tubulars wit...Figure 74 Q‐Q plot comparing experimental and NORSOK N‐004 capacities of tub...Figure 75 Capacity of unrepaired dented joints.Figure 76 Q‐Q plot of results of laboratory tests versus calculations accord...Figure 77 Illustrative Q‐δ curve for a jacket structure with an indicat...Figure 78 Configurations of fixed offshore steel structures (D: diagonal bra...Figure 79 Illustrations of percentage of corrosion per area.Figure 80 Fatigue crack growth rate curve.Figure 81 Failure Assessment Diagram.

8 Chapter 8Figure 82 Cumulative total of platforms by material versus installation year...Figure 83 Cumulative number of repairs normalised by material population ver...Figure 84 Frequency of repairs per structure year versus water depth.Figure 85 Fatigue test results for repair welded tubular joints plotted in t...Figure 86 Fatigue test results obtained for tubular joints repaired by hole ...Figure 87 Fatigue test results for tubular joints repaired by grinding alone...Figure 88 Capacity of repaired and unrepaired dented tubulars based on Ricle...Figure 89 Bolted clamp used on the Viking AD platform after decommissioning....Figure 90 Illustration of the process leading up to SMR.Figure 91 Interrelationship between scenarios, SMR schemes and SMR technique...Figure 92 Repaired prism using grout for compression testing (left) and repa...Figure 93 First four levels of impact damage to concrete slabs.Figure 94 Slab GS1 after test, front and back‐face (Department of Energy 199...Figure 95 An overview of possible repair and mitigation options (overload da...Figure 96 Example of grinding repair.Figure 97 Weld toe grinding.Figure 98 Example of geometry after grinding to remove deep cracks.Figure 99 Fillet weld throat terminology.Figure 100 Illustration of flush grinding of a butt weld.Figure 101 Weld profiling.Figure 102 Example of stop hole repair.Figure 103 (a) Crack (b) stop hole (c) crack‐deflecting hole.Figure 104 Example of a hyperbaric chamber and a diver inside the habitat pe...Figure 105 Example of a diver performing a wet weld.Figure 106 Example of doubler plate repair to a jacket structure.Figure 107 Illustration of bonded patch repair (before and after repair).Figure 108 Schematic diagram of a repair of a tubular K joint using bolted c...Figure 109 Typical grouted clamp for T joints.Figure 110 Grouted sleeve connections.Figure 111 Void formation during grout filling.Figure 112 Grout‐filled joint.Figure 113 Reinforcement methods for stiffened plates, (a) indicates the ori...Figure 114 Kenter shackle.Figure 115 An example of formwork used for concrete repair.

9 Chapter 9Figure 116 Illustration of a digital twin.