Glossary
Browse the IADC Lexicon alphabetically or by category. Get comprehensive definitions of drilling industry terms.
Mill/FAT Test Pressure
Definition(s)
Mill/FAT Test Pressure
Hydrostatic test pressure applied to riser components upon completion of manufacture and fabrication to test the riser components for strength and/or leak tightness. Source: API Standard 2RD, Dynamic Risers for Floating Production Systems, Second Edition, September 2013. Global StandardsMill/FAT Test Pressure
Hydrostatic test pressure applied to riser components upon completion of manufacture and fabrication to test the riser components for strength and/or tightness. Source: API RP 17G, Recommended Practice for Completion/Workover Risers, Second Edition, July 2006 (Reaffirmed April 2011). Global StandardsMean Static Offset
Definition(s)
Mean Static Offset (of vessel)
Mean static offset includes static offset due to steady forces from current, wind and wave, offset due to low-frequency motions and active positioning of the vessel. Source: API RP 17G, Recommended Practice for Completion/Workover Risers, Second Edition, July 2006 (Reaffirmed April 2011). Global StandardsManufacturing Procedure Specification
Definition(s)
Manufacturing Procedure Specification
Document prepared by the manufacturer to demonstrate how the specified properties can be achieved and verified through the proposed manufacturing route. Source: API RP 17G, Recommended Practice for Completion/Workover Risers, Second Edition, July 2006 (Reaffirmed April 2011). Global StandardsLubricator Valve
Definition(s)
Lubricator Valve
Valve assembly typically situated below the surface tree and used to isolate the reservoir from the environment when deploying long wireline/coiled tubing tool assemblies. Source: API RP 17G, Recommended Practice for Completion/Workover Risers, Second Edition, July 2006 (Reaffirmed April 2011). Global StandardsLower Workover Riser Package
Definition(s)
Lower Workover Riser Package
Lowermost equipment package in the riser string when configured for subsea tree installation/workover and including any equipment between the riser stress joint and the subsea tree, and typically consisting of a lower riser package and emergency disconnect package. NOTE The lower workover riser package permits well control and ensures a safe operating status whilst performing coiled tubing/wireline and well servicing operations. Source: API RP 17G, Recommended Practice for Completion/Workover Risers, Second Edition, July 2006 (Reaffirmed April 2011). Global StandardsLower Marine Riser Package
Definition(s)
Lower Marine Riser Package
Upper section of a subsea BOP stack that interfaces between the lower stack and drilling riser, typically consisting of a hydraulic connector, annular BOP, ball/flex joint, riser adapter, jumper lines for the choke, kill, and auxiliary lines, and subsea control pods.
Source: API Specification 16Q, Design, Selection, Operation, and Maintenance of Marine Drilling Riser Systems, Second Edition, April 2017. Global StandardsLower Marine Riser Package (LMRP)
Upper section of a two-section subsea BOP stack consisting of the hydraulic connector, annular BOP, ball/flex joint, riser adapter, jumper hoses for the choke, kill and auxiliary lines and subsea control modules.- NOTE: The LMRP interfaces with the BOP stack.
Lower Marine Riser Package
Upper section of a two-section subsea BOP stack consisting of a hydraulic connector, annular BOP, flex joint, riser adapter, jumper hoses for the choke, kill and auxiliary lines, and subsea control pods.- NOTE: This interfaces with the lower subsea BOP stack.
Low-Frequency Vessel Motion
Definition(s)
Low-Frequency Vessel Motion
Motion response at frequencies below wave frequencies typically with periods ranging from 30 s to 300 s. Source: API Standard 2RD, Dynamic Risers for Floating Production Systems, Second Edition, September 2013. Global Standards Source: API RP 17G, Recommended Practice for Completion/Workover Risers, Second Edition, July 2006 (Reaffirmed April 2011). Global StandardsLoad Effect
Definition(s)
Load Effect
Effect of a single load or combination of loads on the structure, such as stress, strain, deformation, displacement, motion, etc. Source: API Standard 2RD, Dynamic Risers for Floating Production Systems, Second Edition, September 2013. Global Standards Source: API RP 17G, Recommended Practice for Completion/Workover Risers, Second Edition, July 2006 (Reaffirmed April 2011). Global StandardsLoad Effect
Effect of a single design load or combination of loads on the equipment or system, such as stress, strain, deformation, displacement, motion, etc. Source: Offshore Standard DNV-OS-C101, Design of Offshore Steel Structures, General (LRFD Method, Det Norske Veritas, April 2011. Global StandardsLocal Buckling
Definition(s)
Local Buckling
Buckling mode implying deformations of the cross-section. NOTE This can e.g. be due to external pressure (hoop buckling) or moment (wrinkling) or a combination thereof. Source: API Standard 2RD, Dynamic Risers for Floating Production Systems, Second Edition, September 2013. Global Standards Source: API RP 17G, Recommended Practice for Completion/Workover Risers, Second Edition, July 2006 (Reaffirmed April 2011). Global StandardsLoad Case
Definition(s)
Load Case
Combination of simultaneous acting loads. Source: API Standard 2RD, Dynamic Risers for Floating Production Systems, Second Edition, September 2013. Global StandardsLoad Case
Combination of simultaneously acting loads. Source: API RP 17G, Recommended Practice for Completion/Workover Risers, Second Edition, July 2006 (Reaffirmed April 2011). Global StandardsLoad Case
Compatible load arrangements, sets of deformations and imperfections considered simultaneously with permanent actions and fixed variable actions for a particular design or verification. [ISO 19902:2007, definition 3.29]. Source: ISO 19905-1:202, Petroleum and natural gas industries – Site-specific assessment of mobile offshore units – Part 1: Jack-ups. Global StandardsLoad
Definition(s)
Load
Physical influence which causes stress and/or strains in the riser system. Source: API Standard 2RD, Dynamic Risers for Floating Production Systems, Second Edition, September 2013. Global Standards Source: API RP 17G, Recommended Practice for Completion/Workover Risers, Second Edition, July 2006 (Reaffirmed April 2011). Global StandardsLimit Analysis
Definition(s)
Limit Analysis
Method used to compute the resistance of a component made of ideally (rigid) plastic material. Source: API RP 17G, Recommended Practice for Completion/Workover Risers, Second Edition, July 2006 (Reaffirmed April 2011). Global StandardsLifting Device
Definition(s)
Lifting Device
Tool dedicated for lifting. Source: API Standard 2RD, Dynamic Risers for Floating Production Systems, Second Edition, September 2013. Global Standards Source: API RP 17G, Recommended Practice for Completion/Workover Risers, Second Edition, July 2006 (Reaffirmed April 2011). Global StandardsLeak-Tight
Definition(s)
Leak-Tight
Leakage that is acceptable for a particular component. 3.1.49. Source: API Standard 2RD, Dynamic Risers for Floating Production Systems, Second Edition, September 2013. Global StandardsLeak-Tight
Leakage that is acceptable for a particular component. NOTE See 6.4.11.5. Source: API RP 17G, Recommended Practice for Completion/Workover Risers, Second Edition, July 2006 (Reaffirmed April 2011). Global StandardsIntegral Riser
Definition(s)
Integral Riser
Integral style C/WO riser is a riser in which the pressure-containing conduits are mounted into a common assembly or joint. NOTE 1 An integral riser is typically classified as either jacketed or non-jacketed. The integral riser joint allows the production and annulus lines to be made up simultaneously. NOTE 2 A jacketed C/WO riser can also contain hydraulic control lines inside the structural housing. This type of riser is typically used in applications where high tensile or bending loads are anticipated. Source: API RP 17G, Recommended Practice for Completion/Workover Risers, Second Edition, July 2006 (Reaffirmed April 2011). Global StandardsHydrodynamic Loads
Definition(s)
Hydrodynamic Loads
Flow-induced loads caused by the relative motion between the riser and the surrounding water. Source: API RP 17G, Recommended Practice for Completion/Workover Risers, Second Edition, July 2006 (Reaffirmed April 2011). Global StandardsHeat-Affected Zone
Definition(s)
Heat-Affected Zone
The portion of the base metal whose mechanical properties or microstructure have been altered by the heat of welding or thermal cutting. Source: API 510, Pressure Vessel Inspection Code: In-service Inspection, Rating, Repair, and Alteration, Tenth Edition, May 2014, with Addendum May 2017. Global StandardsHeat-Affected Zone
Portion of the base metal that has not been melted, but whose mechanical properties or microstructure has been altered by the heat of welding or cutting. Source: API Specification 16A, Specification for Drill-through Equipment, Fourth Edition, April 2017. Global Standards Source: API STANDARD 16AR, Standard for Repair and Remanufacture of Drill-through Equipment, First Edition, April 2017. Global StandardsHeat-Affected Zone
Region around a weld that has been affected by welding. Source: API RP 17G, Recommended Practice for Completion/Workover Risers, Second Edition, July 2006 (Reaffirmed April 2011). Global StandardsGross Structural Discontinuity
Definition(s)
Gross Structural Discontinuity
Structural or material discontinuity which affects the stress or strain distribution across the entire wall thickness over a region of significant area. EXAMPLE End-to-pipe junction, connector-to-pipe junction, the junction of two pipes of different diameters, thickness or material, or a stiffener-to-pipe junction. Source: API RP 17G, Recommended Practice for Completion/Workover Risers, Second Edition, July 2006 (Reaffirmed April 2011). Global StandardsGrip Length
Definition(s)
Grip Length
Combined thickness of all the elements clamped together by the bolts and nuts, including washers, gaskets and joint members. Source: API RP 17G, Recommended Practice for Completion/Workover Risers, Second Edition, July 2006 (Reaffirmed April 2011). Global StandardsGlobal Buckling
Definition(s)
Global Buckling
Elastic Euler buckling. Source: API RP 17G, Recommended Practice for Completion/Workover Risers, Second Edition, July 2006 (Reaffirmed April 2011). Global StandardsGlobal Analysis
Definition(s)
Global Analysis
Analysis of the complete riser string from the sea floor (wellhead) to top including tensioner joint. NOTE Bending moments and effective tension distributions along the riser string due to functional loads, vessel motions and environmental loads are determined by global analysis. Source: API Standard 2RD, Dynamic Risers for Floating Production Systems, Second Edition, September 2013. Global StandardsGlobal Analysis
Analysis of the complete riser string from the sea floor (wellhead) to top drive including tensioner joint, utilizing beam element. NOTE Bending moments and effective tension distributions along the riser string due to functional loads, vessel motions and environmental loads are determined by global analysis. Source: API RP 17G, Recommended Practice for Completion/Workover Risers, Second Edition, July 2006 (Reaffirmed April 2011). Global StandardsGlobal Analysis
Determination of a consistent set of internal forces and moments, or stresses, in a structure that are in equilibrium with a defined set of actions on the entire structure. NOTE 1 When a global analysis is of a transient situation (e.g. earthquake), the inertial response is part of the equilibrium. NOTE 2 Adapted from ISO 19902:2007, definition 3.23. Source: ISO 19905-1:202, Petroleum and natural gas industries – Site-specific assessment of mobile offshore units – Part 1: Jack-ups. Global StandardsGimbal
Definition(s)
Gimbal
Device that interfaces with the spider and the riser joint and enables the riser to rotate about the horizontal axis, thereby reducing the bending moments, which can otherwise occur due to vessel roll/pitch motions. Source: API RP 17G, Recommended Practice for Completion/Workover Risers, Second Edition, July 2006 (Reaffirmed April 2011). Global StandardsGasket
Definition(s)
Gasket
Deformable material (or combination of materials) used to prevent leakage of fluid between two surfaces. Source: API Standard 2RD, Dynamic Risers for Floating Production Systems, Second Edition, September 2013. Global StandardsGasket
Deformable material (or combination of materials) intended to be clamped between flanges to prevent leakage of fluid. Source: API RP 17G, Recommended Practice for Completion/Workover Risers, Second Edition, July 2006 (Reaffirmed April 2011). Global StandardsFrequency Domain
Definition(s)
Frequency Domain
Dynamic analysis method based on the assumption that any applied irregular process is a superposition of fundamental, regular processes. NOTE Frequency domain analysis is usually associated with linear systems. Source: API RP 17G, Recommended Practice for Completion/Workover Risers, Second Edition, July 2006 (Reaffirmed April 2011). Global StandardsFracture Mechanics Assessment
Definition(s)
Fracture Mechanics Assessment
Assessment and analysis where critical defect sizes under design loads are identified to determine the crack growth life, i.e. leak or fracture. Source: API Standard 2RD, Dynamic Risers for Floating Production Systems, Second Edition, September 2013. Global Standards Source: API RP 17G, Recommended Practice for Completion/Workover Risers, Second Edition, July 2006 (Reaffirmed April 2011). Global StandardsFractile
Definition(s)
Fractile
p-fractile (or percentile) and the corresponding fractile value Xp is defined as F(Xp) = p, where F is the distribution function for Xp. Source: API RP 17G, Recommended Practice for Completion/Workover Risers, Second Edition, July 2006 (Reaffirmed April 2011). Global StandardsFluid
Definition(s)
Fluid
substance that has no fixed shape and yields easily to external pressure- Note 1 to entry: A fluid can be either a gas or a liquid.
Fluid
Gases, liquids and vapour in pure phases as well as mixtures thereof. Source: API RP 17G, Recommended Practice for Completion/Workover Risers, Second Edition, July 2006 (Reaffirmed April 2011). Global StandardsFluid
"Fluid" means any material or substance that flows or moves, whether in a semi-solid, liquid, sludge, gaseous, or other form or state. Source: Alaska Oil and Gas Conservation Commission, Definitions, Alaska Admin. Code tit. 20, § 25.990, December 7, 2012. RegulationsFluid
“Fluid” means gas, liquid or a combination of the two fluide. Source: Canada Oil and Gas Drilling and Production Regulations, SOR/2009-315, February 2013. Regulations Source: Drilling and Production Guidelines, The Canada-Nova Scotia Offshore Petroleum Board and Canada-Newfoundland and Labrador Offshore Petroleum Board, Canada, March 31, 2011. Regulatory Guidance Source: Nova Scotia Offshore Petroleum Drilling and Production Regulations, SOR/2009-317, Canada, current to May 31, 2012. RegulationsFluids
Fluids mean liquids and gases. Source: Guidelines Regarding the Facilities Regulations, Norway, updated December 2012. Regulatory GuidanceFloating Vessel
Definition(s)
Floating Vessel
Installation which is floating and positioned relative to the sea bottom by station-keeping systems such as catenary mooring systems, vertical tendons, and dynamic positioning systems based on thrusters. Source: API Standard 2RD, Dynamic Risers for Floating Production Systems, Second Edition, September 2013. Global StandardsFloating Vessel
Buoyant installation that is floating and positioned relative to the sea bottom by station keeping systems. NOTE The following types of station-keeping systems are normally considered: catenary mooring systems and dynamic positioning systems based on thrusters. Combination of station-keeping systems can be considered. EXAMPLE Semi- submersible drilling vessels and drill ships. Source: API RP 17G, Recommended Practice for Completion/Workover Risers, Second Edition, July 2006 (Reaffirmed April 2011). Global StandardsFinite Element Analysis (FEA)
Definition(s)
Finite Element Analysis
Numerical method for analyzing dynamic and static response, by dividing the structure into small continuous elements with the given material properties.- NOTE: The analysis can be local or global.