Glossary
Browse the IADC Lexicon alphabetically or by category. Get comprehensive definitions of drilling industry terms.
Previous Greenhouse Gas Regulations
Definition(s)
Previous greenhouse gas Regulations
Previous greenhouse gas Regulations means the Offshore Petroleum and Greenhouse Gas Storage (Management of Greenhouse Gas Well Operations) Regulations 2010. Source: Offshore Petroleum and Greenhouse Gas Storage (Resource Management and Administration) Regulations 2011 (Select Legislative Instrument 2011 No. 54 as amended), Australia, prepared on 1 January 2012. RegulationsWell Integrity Hazard
Definition(s)
Well integrity hazard
Well integrity hazard means:- an event that:
- may compromise the integrity of a well; and
- would, if it occurred, have the consequence of a significant threat to the safety of individuals; or
- an event that may involve a risk of significant damage to the environment or the well reservoir of a well.
Time Domain
Definition(s)
Time Domain
Timewise, incremental simulation of riser response. NOTE Offers the capability of modelling hydrodynamic and structural non-linearity. Source: API RP 17G, Recommended Practice for Completion/Workover Risers, Second Edition, July 2006 (Reaffirmed April 2011). Global StandardsWell Activity
Definition(s)
Well activity
Well activity means an activity relating to a well that is carried out during the life of the well. Examples:- Exploratory drilling.
- Production drilling.
- Appraisal drilling.
- Testing a well.
- Well drilling.
- A wireline operation.
- A workover operation.
- A well completion or re-completion.
- Maintenance of a well.
- Abandonment or suspension of a well.
Tensioner System
Definition(s)
Tensioner System
Device that applies a tension to the riser string while compensating for the relative vertical motion (stroke) between the floating vessel and the top of the deployed riser string. Source: API Standard 2RD, Dynamic Risers for Floating Production Systems, Second Edition, September 2013. Global StandardsTensioner System
Device that applies a close to constant tension to the riser string while compensating for the relative vertical motion (stroke) between the floating vessel and the top of the deployed riser string. Source: API RP 17G, Recommended Practice for Completion/Workover Risers, Second Edition, July 2006 (Reaffirmed April 2011). Global StandardsTension Ring
Definition(s)
Tension Ring
Attachment point on the tension joint for the floating vessel tensioners. Source: API Standard 2RD, Dynamic Risers for Floating Production Systems, Second Edition, September 2013. Global StandardsTension Ring
Attachment point on the tension joint for the floating vessel tensioning lines. Source: API RP 17G, Recommended Practice for Completion/Workover Risers, Second Edition, July 2006 (Reaffirmed April 2011). Global StandardsTension Ring
Support ring around the top of the joint where tensioner lines are attached. Source: ISO 13624-1:2009, Petroleum and natural gas industries – Drilling and production equipment – Part 1:Design and operation of marine drilling riser equipment. Global StandardsTension Joint
Definition(s)
Tension Joint
Special riser joint which provides a means for attaching a vertical riser to the floating vessel's tensioning system. Source: API Standard 2RD, Dynamic Risers for Floating Production Systems, Second Edition, September 2013. Global StandardsTension Joint
Special riser joint that provides a means for tensioning the C/WO riser with the floating vessel's tensioning system during open-sea workover mode. NOTE When in use, the tension joint is located below the slick joint, which has a provision for attaching the tensioner unit to the riser. Source: API RP 17G, Recommended Practice for Completion/Workover Risers, Second Edition, July 2006 (Reaffirmed April 2011). Global StandardsSignificant Event
Definition(s)
Significant event
Significant event includes the following:- a change in the understanding of the characteristics of the geology or reservoir that may have a significant impact on the optimum recovery of petroleum;
- a new or increased risk to the recovery of petroleum within the licence area;
- a new or increased risk to the recovery of petroleum outside the licence area caused by the development of pools in the licence area;
- a new or increased risk of activities in the licence area causing effects outside the licence area (for example aquifer depletion caused by hydrocarbon extraction);
- change to the proposed option for development of pools in the licence area, including any tie-in opportunity with nearby licence areas.
System Test Pressure
Definition(s)
System Test Pressure
Test pressure applied to the riser during system field pressure test of the C/WO riser system performed after installation and before start of operation. Source: API RP 17G, Recommended Practice for Completion/Workover Risers, Second Edition, July 2006 (Reaffirmed April 2011). Global StandardsSystem Pressure Test
Definition(s)
System Pressure Test
Field hydrostatic leak-tightness pressure test of the complete riser system performed after installation and before start of operation. 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 StandardsMajor Change
Definition(s)
Major change
Major change, in relation to the recovery of petroleum from a field, includes the following:- the petroleum production licensee changes the development strategy or management strategy of a field or a petroleum pool;
- the petroleum production licensee changes the plan for the development of additional pools in the field;
- the petroleum production licensee ceases production, permanently or for the long term, before the date proposed in the field development plan;
- the petroleum production licensee introduces new methods for the petroleum recovery, such as enhanced recovery and injection of fluids.
Licence Area
Definition(s)
Licence area
Licence area, in relation to an applicant for a petroleum production licence, means the area constituted by the block or blocks that will be the subject of the petroleum production licence if the licence is granted. Source: Offshore Petroleum and Greenhouse Gas Storage (Resource Management and Administration) Regulations 2011 (Select Legislative Instrument 2011 No. 54 as amended), Australia, prepared on 1 January 2012. RegulationsLicence area
Licence area:- when used in relation to an infrastructure licence—means the place in relation to which the infrastructure licence is in force; or
- when used in relation to a petroleum production licence—means the area constituted by the block or blocks that are the subject of the petroleum production licence; or
- when used in relation to a greenhouse gas injection licence—means the area constituted by the block or blocks that are the subject of the greenhouse gas injection licence. Note: The place in relation to which an infrastructure licence is in force must be a place in an offshore area—see subsection 198(2) and section 199.
Surge Pressure
Definition(s)
Surge Pressure
Pressure produced by sudden changes in the velocity of the moving stream of fluids inside the riser. 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 StandardsPressure Control
Rapid change in line or vessel pressure. Source: IADC UBO / MPD Glossary, December 2011. Global StandardsSupport Shoulder
Definition(s)
Support Shoulder
Shoulder or projection on the external surface of a connector or the riser component for supporting the riser system or well control equipment during riser running operations. Source: API RP 17G, Recommended Practice for Completion/Workover Risers, Second Edition, July 2006 (Reaffirmed April 2011). Global StandardsSurface Tree Adapter Joint
Definition(s)
Surface Tree Adapter Joint
Crossover from the standard riser joint connector to the connection at the bottom of the surface tree. NOTE Its bore configuration is consistent with the standard riser joint. This speciality joint is usually made up to the surface tree prior to installation. Source: API RP 17G, Recommended Practice for Completion/Workover Risers, Second Edition, July 2006 (Reaffirmed April 2011). Global StandardsSurface Tree
Definition(s)
Surface Tree
Device placed at top of the riser string that provides flow control of the production and/or annulus bores during production. Source: API Standard 2RD, Dynamic Risers for Floating Production Systems, Second Edition, September 2013. Global StandardsSurface Tree
Device which provides flow control of the production and/or annulus bores during both tubing hanger installation and subsea tree installation/workover operations. NOTE It can also have provisions to support the mass of the C/WO riser system. Source: API RP 17G, Recommended Practice for Completion/Workover Risers, Second Edition, July 2006 (Reaffirmed April 2011). Global StandardsSubsea Test Tree
Definition(s)
Subsea Test Tree
Assembly of valves positioned above the tubing hanger running tool located inside the subsea BOP and equivalent to the lower workover riser package. NOTE It is used to secure the well and provides a disconnect point for the C/WO riser. The subsea test tree can be configured for operation on horizontal or vertical trees. Source: API RP 17G, Recommended Practice for Completion/Workover Risers, Second Edition, July 2006 (Reaffirmed April 2011). Global StandardsStroke
Definition(s)
Stroke.
One current component of a lightning flash. The number of strokes per flash is typically three to four, but may be as low as one or as high as 30 (Uman, All About Lightning, p. 41). Source: API RP 545 Recommended Practice for Lightning Protection of Aboveground Storage Tanks for Flammable or Combustible Liquids, First Edition, October 2009. Global StandardsStroke
Total vertical movements (upward and downward) of the riser relative to the vessel which is also the travel of the riser tensioner.- NOTE: Stroke is affected by environmental loads, functional loads (i.e. top tension, temperature and mean static vessel offset) and pressure.
Stroke
Total upward and downward vertical movements of the riser relative to the vessel, i.e. travel of the riser tensioner, draw works and slick joint.- NOTE: It includes effects from environmental loads, functional loads (i.e. top tension, temperature and mean static vessel offset) and pressure.
Stress Range
Definition(s)
Stress Range
The difference between stress maximum and stress minimum in a stress cycle. 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 StandardsStress Joint
Definition(s)
Stress Joint
Specialized riser joint designed with a tapered cross-section to control curvature and reduce local bending stresses. Source: API Standard 2RD, Dynamic Risers for Floating Production Systems, Second Edition, September 2013. Global StandardsStress Joint
Specialized riser joint designed with a tapered cross-section, in order to control curvature and reduce local bending stresses. NOTE It is the lowermost riser joint in the riser string when configured for workover. Source: API RP 17G, Recommended Practice for Completion/Workover Risers, Second Edition, July 2006 (Reaffirmed April 2011). Global StandardsStress Intensity Factor
Definition(s)
Stress Intensity Factor
Term used in fracture mechanics to define the local conditions of stress and strain around a crack tip, in terms of global parameters such as of loads, geometry and crack size. Source: API Standard 2RD, Dynamic Risers for Floating Production Systems, Second Edition, September 2013. Global StandardsStress Intensity Factor (Fracture Mechanics)
Factor used to define the local conditions of stress and strain around a crack tip in terms of global parameters such as of loads, geometry and crack size. Source: API RP 17G, Recommended Practice for Completion/Workover Risers, Second Edition, July 2006 (Reaffirmed April 2011). Global StandardsStress Concentration Factor
Definition(s)
Stress Concentration Factor
Equal to the local peak stress in a component (including welds) divided by the nominal stress in the component cross-section at the location of the local peak stress.
Source: API Technical Report 17TR7, Verification and Validation of Subsea Connectors, First Edition, April 2017. Global StandardsStress Concentration Factor (SCF)
Local peak alternating stress in a component (including welds) divided by the nominal alternating stress in the pipe wall at the location of the component.- NOTE: This factor is used to account for the increase in the stresses caused by geometric stress amplifiers that occur in the riser component.
Stress Concentration Factor (SCF)
Local peak alternating stress in a component (including welds) divided by the nominal alternating stress in the pipe wall at the location of the component.- NOTE: This factor is used to account for the increase in the stresses caused by geometric stress amplifiers, which occur in the riser component.
Stress Concentration Factor
Factor relating a nominal stress to the local stress at a detail. NOTE Adapted from ISO 19902:2007, definition 3.50. Source: ISO 19905-1:202, Petroleum and natural gas industries – Site-specific assessment of mobile offshore units – Part 1: Jack-ups. Global StandardsStrength
Definition(s)
Strength
Mechanical property of a material, usually given in units of stress. 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 StandardsStab Sub
Definition(s)
Stab Sub
Male half of sealing mechanism between component interfaces. NOTE Stab subs can use elastomeric or metal seals or both. Source: API RP 17G, Recommended Practice for Completion/Workover Risers, Second Edition, July 2006 (Reaffirmed April 2011). Global StandardsSplash Zone
Definition(s)
Splash Zone
The area of the structure that is intermittently wet and dry due to wave and tidal action. Source: API RP 2SIM, Structural Integrity Management of Fixed Offshore Structures, First Edition, November 2014. Global StandardsSplash Zone
Part of the riser subjected to repeated wetting and drying by seawater. Source: API RP 17G, Recommended Practice for Completion/Workover Risers, Second Edition, July 2006 (Reaffirmed April 2011). Global StandardsSplash Zone
part of a structure that is intermittently exposed to air and immersed in the sea Source: ISO 19900:2013, Petroleum and natural gas industries – General requirements for offshore structures. Global StandardsSplash Zone
The external surfaces of the unit that are periodically in and out of the water. The determination of the splash zone includes evaluation of all relevant effects including influence of waves, tidal variations, settlements, subsidence and vertical motions, see Sec.10 B200. Source: Offshore Standard DNV-OS-C101, Design of Offshore Steel Structures, General (LRFD Method, Det Norske Veritas, April 2011. Global StandardsSplash Zone
That part of the external structure above the boot topping zone subject to wet and dry conditions. Source: Rules and Regulations for the Classification of Mobile Offshore Units, Part 8, Corrosion Controls, June 2013, Lloyd’s Register, Global StandardsSpider
Definition(s)
Spider
Device having retractable jaws or dogs used to support the riser on the uppermost connector support shoulder during running of the riser. NOTE The handling spider sits either on the rotary bushing or in the rotary table. It provides a hang-off point for the integral C/WO riser. Some spiders will lock to the rotary via the kelly drive pinholes in the master bushing. With the pins engaged, the spider can resist torque. For non-integral risers, tubing slips and false rotaries are used in lieu of the spider. Source: API RP 17G, Recommended Practice for Completion/Workover Risers, Second Edition, July 2006 (Reaffirmed April 2011). Global StandardsSpider
A device for the purpose of suspending tubular goods of any type from the drilling structure, not capable of being used as elevators, that have some element on the internal diameter to grip the outer diameter surface of the pipe body of various tubular goods, that are operated manually or by spring(s) and/or pneumatic or hydraulic power or other assist device or method.
Source:API SPECIFICATION 7K, Drilling and Well Servicing Equipment, Sixth Edition, December 2015. Global StandardsSpecified Minimum Yield Strength
Definition(s)
Specified Minimum Yield Strength
Minimum yield strength at room temperature prescribed by the specification or standard under which the material is purchased. Source: API Technical Report 17TR7, Verification and Validation of Subsea Connectors, First Edition, April 2017. Global Standards 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 StandardsSpecified Minimum Yield Strength (SMYS)
The minimum yield strength prescribed by the specification or standard under which the material is purchased. Source: Offshore Standard DNV-OS-C101, Design of Offshore Steel Structures, General (LRFD Method, Det Norske Veritas, April 2011. Global StandardsS-N Curve
Definition(s)
S-N Curve
Quantitative relationship between the fatigue stress, S, and the number of cycles, N, corresponding to a specific probability of failure for a detail, derived from test data.
Source: API Technical Report 17TR7, Verification and Validation of Subsea Connectors, First Edition, April 2017. Global StandardsS-N Curve
A plot of stress range (S) against the number of cycles (N) to failure obtained by cycling specimens to failure. Source: API Standard 2RD, Dynamic Risers for Floating Production Systems, Second Edition, September 2013. Global StandardsS-N Curve
Graphical presentation of the dependence of fatigue life, N, on fatigue strength, S. NOTE It is also known as the Wöhler curve. Source: API RP 17G, Recommended Practice for Completion/Workover Risers, Second Edition, July 2006 (Reaffirmed April 2011). Global StandardsSlick Joint
Definition(s)
Slick Joint
Riser joint of standard length without attached buoyancy.
Source: API Specification 16Q, Design, Selection, Operation, and Maintenance of Marine Drilling Riser Systems, Second Edition, April 2017. Global Standards