| Accidental limit state (ALS) | Check of the collapse of the structure due to the same reasons as described for the ultimate limit state but exposed to abnormal and accidental loading situations |
| Acoustic emission | The production of sound waves by a material when it is subjected to stress |
| ACFM | Alternating Current Frequency Modulated (type of inspection) |
| ACPD | Alternating Current Potential Drop (type of inspection) |
| Admixture | Material added during the mixing process of concrete in small quantities related to the mass of cement to modify the properties of fresh or hardened concrete |
| Ageing | Process in which integrity (i.e., safety) of a structure or component changes with time or use |
| AIM project | A project undertaken by the US Mineral Management Services (MMS) for assessment, inspection and maintenance, providing guidance on managing the integrity of existing fixed steel platforms in the Gulf of Mexico. |
| Anomaly | In‐service measurement (damage, deterioration, defect, degradation, etc.) that is outside the threshold acceptable from the design or most recent fitness for service assessment |
| As‐built documentation | Documentations that includes as‐built documentation collected during in‐service |
| Asset integrity management (AIM) | AIM is the means of ensuring that the people, systems, processes and resources that deliver integrity are in place, in use and will perform when required over the whole life cycle of the asset |
| Barrier | A measure intended to either identify conditions that may lead to failure or hazardous and accidental situations, prevent an actual sequence of events occurring or developing, influence a sequence of events in a deliberate way, or limit damage and/or loss |
| Bilge | The area on the outer surface of a ship's hull where the bottom shell plating meets the side shell plating |
| Caisson | Major part of fixed concrete offshore structure, providing buoyancy during floating phases and the possibility of oil storage within the structure, also used for pipework from topside to underwater typically water lift (intake of firewater, cooling water, etc.) and outlet of wastewater |
| CFRP | Carbon Fiber Reinforced Polymer |
| Clamp | A fabricated steel construction encompassing an existing tubular member or a nodal joint. A clamp consists of two or more parts that are bolted together. There are a number of clamp variants depending on whether or not the clamp parts are compressed against the existing member/joint and on whether there is a medium (grout or neoprene) placed between the clamp steelwork and the member/joint. A clamp should not be confused with a guide, which can appear to be superficially similar |
| Collapse | Total loss of the load bearing capacity of the platform through failure of one or more structural components |
| CP | Cathodic Protection |
| Curing | Action taken to maintain favourable moisture and temperature conditions of freshly placed concrete or cementitious materials during a defined period of time following placement |
| CVI | Close visual inspection (type of inspection) |
| Defect | An imperfection, fault or flaw in a component |
| Design service life | Assumed period for which a structure is to be used for its intended purpose with anticipated maintenance but without substantial repair from ageing processes being necessary |
| DFI resume | A document summarising key information concerned with the design, fabrication and installation |
| Discontinuity | A lack of continuity or cohesion; an intentional or unintentional interruption in the physical structure or configuration of a material or component |
| Duty holder | A UK term for the operator in the case of a fixed installation (including fixed production and storage units) and for the owner in the case of a mobile installation |
| DVI | Detailed visual inspection (type of inspection) |
| EC, ET | Eddy current testing (type of inspection) |
| Evaluation | The process of evaluating whether identified changes, defects or anomalies need repair, further inspection or a more detailed assessment |
| Fairlead | A device to guide a mooring line and to stop it moving laterally before it enters the vessel |
| False indication | An indication that is interpreted to be caused by a discontinuity at a location where no discontinuity exists |
| Fatigue limit state (FLS) | Check of the cumulative fatigue damage due to repeated loads or the fatigue crack growth capacity of the structure |
| Fatigue Utilisation Index (FUI) | FUI is the ratio between the effective operational time and the documented fatigue life |
| FCAW | Acronym for Fluxed Cored Arc Welding |
| Fixed structure | Structure that is bottom founded and transfers all actions on it to the sea floor |
| Flaw | An imperfection or discontinuity that may be detectable by non‐destructive testing |
| FRP | Fiber Reinforced Polymer |
| FSU | Floating storage units |
| FSO | Floating storage and offloading units |
| FPSO | Floating production, storage and offloading units |
| Flooded member detection (FMD) | Inspection technique that relies on the detection of water penetrating a member by using radiographic or ultrasonic methods |
| GMAW | Gas Metal Arc Welding |
| Gross errors | Significant errors, mistakes and omissions in the form of anomaly or defects that may lead to local or global failures |
| Grout | A mixture of cementitious materials and water, with or without aggregate, to fill cavities and components to form a solid mass when set |
| GTAW | Gas Tungsten Arc Welding |
| GVI | General visual inspection (type of inspection) |
| HAZ | Heat affected zone related to welding |
| Hazard | Situations with potential for human injury, damage to the environment, damage to property, or a combination of these |
| High Strength Steels (HSS) | Steels with yield strengths in excess of 500 MPa |
| Hydrogen induced cracking (HIC) or hydrogen induced stress cracking (HISC) | The process by which hydride‐forming metals such as steel become brittle and fracture due to the introduction and subsequent diffusion of hydrogen into the metal |
| Inspection programme | Scope of work for the offshore execution of the inspection activities to determine the condition and configuration of the structure |
| Integrity | The state of the structure, ideally being fit for service, and with an acceptable level of safety against failure |
| Integrity management | Continuous process to manage all changes that will occur during operational life that may affect the integrity of structures and marine systems |
| Jack‐ups | Mobile offshore unit with a buoyant hull and legs that can be moved up and down relative to the hull |
| JIP | Joint Industry Project, usually in research and development |
| Kenter shackle | A device for joining two chain links as a repair |
| KPI | Key performance indicator, measurement of performance against targets |
| Life extension | The use of structures beyond their originally defined design life |
| Limit state | A state beyond which the structure no longer fulfils the relevant design criteria |
| Management of change (MoC) | A recognised process that is required when significant changes are made to an activity or process which can affect performance and risk |
| Marine fouling (growth) | Seaweed, bacteria and other living organisms in the seawater typically adhering to immersed surfaces such as offshore structures, which may build up to significant thicknesses |
| Metocean | Syllabic abbreviation of meteorology and (physical) oceanography |
| Microbiologically induced cracking (MIC) | A form of degradation that can occur as a result of the metabolic activities of bacteria in the environment. The bacteria that cause MIC can accelerate the corrosion process because the conditions that apply already have elements of a corrosion cell |
| MIG | Metal Inert Gas |
| Mitigation | Limitation of negative consequence or reduction in likelihood of a hazardous event or condition |
| MMA | Manual Metal Arc |
| MPI | Magnetic Particle Inspection (type of inspection) |
| Mudmat | A structure used to prevent offshore structures from sinking into soft unconsolidated soil on the seabed. |
| NDE | Non‐Destructive Examination |
| NDT | Non‐Destructive Testing |
| Node | Joining point for brace members in a jacket‐type structure |
| Non‐redundant | Structure that fails when the first primary structural member fails |
| OPB | Out‐of‐Plane Bending |
| Partial safety factor | (for materials) factor that takes into account unfavourable deviation of strength from the characteristic value and inaccuracies in determining the actual strength of the material (for loads) factor that takes into account the possible deviation of the actual loads from the characteristic value and inaccuracies in the load determination |
| Passive fire protection (PFP) | Coatings used on critical areas that could be affected by a jet fire. There are several different types, which include cementitious and epoxy intumescent based |
| Peening | Process of working a metal’s surface to improve its material properties, usually by mechanical means |
| Performance standards | Statement of the performance required of a structure, system, equipment, person or procedure and that is used as the basis for managing the hazard through the life cycle of the platform |
| Pre‐stressing tendons | High strength tendons required to maintain the structural integrity of a concrete structure, particularly in the towers (shafts). These tendons are placed in steel ducts, which are grouted following tensioning |
| Primary structure | All main structural components that provide the structure’s main strength and stiffness |
| Progressive collapse | The sequence of component failures (from an initial local failure) that will eventually lead to the collapse of an entire structure or large part of it |
| Push‐over analysis | Non‐linear analysis for jacket structures used for determining the collapse / ultimate capacity |
| PWHT | Post Weld Heat Treatment |
| Redundancy | The ability of a structure to find alternative load paths following failure of one or more components, thus limiting the consequences of such failures |
| Reserve strength ratio (RSR) | The ratio between the design loading (usually 100‐year loading) and the collapse / ultimate capacity |
| Residual strength | Ultimate global strength of an offshore structure in a damaged condition |
| Return period | An engineering simplification representing the probability (q) of an event by an assumed average period between occurrences of an event or of a particular value being exceeded. For q less than 0.1 this corresponds approximately to a return period of 1/q years |
| Risk based inspection | Inspection plans developed from an evaluation of the likelihood and consequences of failure associated with a structure to develop the inspection scope and frequency |
| Robustness | Measure of the ability of the structure to be damage tolerant and to sustain deviations from the assumptions to which the structure originally was designed |
| ROV | Remotely Operated Vehicle |
| RT | Radiographic testing (type of inspection) |
| Safety critical elements (SCE) and Safety and environmental critical elements (SECE) | Systems and components (e.g., hardware, software, procedures) that are designed to prevent, control, mitigate or respond to a major accident event (MAE) that could lead to injury or death. This was further extended in the 2015 version of the UK safety case regulation to include environmental critical elements |
| SCF | Stress Concentration Factor |
| Scour | Erosion of the seabed around a fixed structure produced by waves, currents and ice |
| Secondary structure | Structural components that, when removed, do not significantly alter the overall strength and stiffness of the global structure |
| Serviceability limit state (SLS) | A check of functionalities related to normal use (such as deflections and vibrations) in structures and structural components |
| Sleeve | A sleeve is a concentric tubular surrounding a leg or brace member that is several diameters long. The annular gap between the sleeve and member is normally grouted. In the case of an existing member, the sleeve is necessarily split longitudinally and the two halves are joined during installation using short bolts |
| SMR | Strengthening, Modification and Repair |
| SMYS | Specified Minimum Yield Stress |
| S‐N curve | A relationship between applied stress range (S) and the number of cycles (N) to fatigue failure (regarding fatigue failure, see fatigue limit state) |
| Splash zone | Part of a structure close to sea level that is intermittently exposed to air and immersed in the sea |
| SSC | Ship Structures Committee |
| SPT | Sacrificial pre‐treatment technique (used in adhesive repair) |
| Station keeping system | System capable of limiting the excursions of a floating structure within prescribed limits |
| Stress concentration factor (SCF) | Factor relating a nominal stress to the local structural stress at a detail |
| Structural integrity | A state of being intact and fit for purpose, with an acceptable level of safety against failure |
| Structural integrity management (SIM) | Means of demonstrating that the people, systems, processes and resources that deliver structural integrity are in place, in use and will perform when required of the whole life cycle of the structure |
| Structural reliability analysis (SRA) | Method used to analyse the probability of limit state failure of structures |
| Stud (chain) | Crossbar in the centre of a link of a chain, either welded or mechanically fixed |
| Studbolt | A threaded rod, generally used in stressed clamps |
| Subsidence | Settlement of the structure that results, primarily from extraction of reservoir hydrocarbons |
| Surveillance | All activities performed to gather information required to assure the structural integrity, such as inspection of the condition and configuration, determining the loads, records, and document review (such as standards and regulations) |
| Testing | Testing or examination of a material or component in accordance with a guideline, or a standard, or a specification or a procedure in order to detect, locate, measure and evaluate flaws |
| TIG | Tungsten Inert Gas |
| Topsides | Structures and equipment placed on a supporting structure (fixed or floating) to provide some or all of a platform’s functions |
| Ultrasonic testing | A family of non‐destructive testing techniques based on the propagation of ultrasonic waves in the object or material being tested |
| Ultimate limit state (ULS) | A check of failure of the structure of one or more of its members due to fracture, rupture, instability, excessive inelastic deformation, etc. |
| Vibration monitoring | Natural frequency monitoring to measure stiffness |
| Watertight integrity | The capability of preventing the passage of water through the structure at a given pressure head |
| Wave‐in‐deck | Waves that impact the deck of a structure, which dramatically increase the wave loading on the structure |
