Glossary
Browse the IADC Lexicon alphabetically or by category. Get comprehensive definitions of drilling industry terms.
Wellhead Growth
Definition(s)
Wellhead growth
Wellhead growth is the term used for axial movement of the wellhead relative to its initial position at the mudline. Wellhead growth is caused by the forces exerted on the wellhead by: thermal expansion/contraction of tubulars tied back to the wellhead and subsidence, and increasing pressure within the annuli created between the tubulars. Source: API RP 96, Deepwater Well Design and Construction, First Edition, March 2013. Global StandardsWellhead Housing Pressure Boundary
Definition(s)
Wellhead Housing Pressure Boundary
Wellhead housing from the top of the wellhead to where the lowermost seal assembly seals. Source: API SPEC 17D, Design and Operation of Subsea Production Systems—Subsea Wellhead and Tree Equipment, Upstream Segment, Second Edition May 2011 (Errata September 2011). Global StandardsWellsite
Definition(s)
Location
The point at which a well is to be drilled. Also referred to as “wellsite.” Source: API RP 54, Recommended Practice for Occupational Safety for Oil and Gas Well Drilling and Servicing Operations, Third Edition, August 1999 (2007). Global Standardswellsite-based personnel
Definition(s)
wellsite-based personnel
Personnel who are organized and responsible for supporting well construction activities at the wellsite. Source: API Bulletin 97, Well Construction Interface Document Guidelines, First Edition, December 2013. Global StandardsWet
Definition(s)
Wet
A gas system is defined as wet if part of the system operates below the water dew point. Source: API RP 17A, Design and Operation of Subsea Production Systems—General Requirements and Recommendations, Fourth Edition, Reaffirmed 2011. Global StandardsWet Gas
Definition(s)
Wet Gas
Gas containing water or condensate vapor. Source: IADC UBO / MPD Glossary, December 2011. Global StandardsWet Repair
Definition(s)
Wet repair
Repair of a flexible pipe in situ. Source: API RP 17L2, Recommended Practice for Flexible Pipe Ancillary Equipment, First Edition, March 2013. Global StandardsWet Shelf Life
Definition(s)
Wet shelf life
Wet shelf life is defined as the time that an initially fully charged battery can be stored at 25 °C (77 °F) until permanent cell damage occurs.
Source: API Recommended Practice 14FZ, Recommended Practice for Design, Installation, and Maintenance of Electrical Systems for Fixed and Floating Offshore Petroleum Facilities for Unclassified and Class I, Zone 0, Zone 1, and Zone 2 Locations, Second Edition, May 2013. Global StandardsWet shelf life
Wet shelf life is defined as the time that an initially fully charged battery can be stored at 77 °F (25 °C) until permanent cell damage occurs. Source: API RP 14F, Design, Installation, and Maintenance of Electrical Systems for Fixed and Floating Offshore Petroleum Facilities for Unclassified and Class 1, Division 1 and Division 2 Locations, Fifth Edition, July 2008. Global StandardsWet Weight
Definition(s)
Wet Weight
Submerged weight including content minus buoyancy. Source: API RP 17G, Recommended Practice for Completion/Workover Risers, Second Edition, July 2006 (Reaffirmed April 2011). Global StandardsWetted Area
Definition(s)
Wetted Area
Surface area of a tank exposed to liquid on the interior and heat from a fire on the exterior. Source: API STD 2000, Venting Atmospheric and Low-pressure Storage Tanks, Sixth Edition, November 2009. Global StandardsWetted Surface
Definition(s)
Wetted Surface
Any surface that has contact with pressurized well fluid, either by design or because of internal seal leakage. Source: API SPEC 6A, Specification for Wellhead and Christmas Tree Equipment, Twentieth Edition, October 2010 (Addendum November 2012). Global StandardsWetted Surface
Any surface which will be in contact with pressurized well fluid either by design or because of internal seal leakage. Source: API SPEC 16C, Specification for Choke and Kill Systems, First Edition, January 1993 (Reaffirmed 2001). Global StandardsWetting Agent
Definition(s)
Wetting Agent
Substance which lowers the surface tension of a liquid. Source: API RP 5A5, Field Inspection of New Casing, Tubing, and Plain-end Drill Pipe, Reaffirmed August 2010. Global StandardsWeymouth Formula
Definition(s)
Weymouth Formula
Equation used to calculate flow in line or vessels. Source: IADC UBO / MPD Glossary, December 2011. Global StandardsWH
Definition(s)
WH
Well Head. Source: Norwegian Oil and Gas Association, Guideline No. 135, Recommended Guidelines for Classification and categorization of well control incidents and well integrity incidents, Rev. 4, 27 June 2017, National or Regional StandardsWH
Wellhead Area Source: ISO 13702:2015, Petroleum and natural gas industries — Control and mitigation of fires and explosions on offshore production installations — Requirements and guidelines, Second Edition, August 2015. Global StandardsWhip Line
Definition(s)
Whip Line
A secondary hoist rope (if present) on a crane. Source: API RP 2D, Operation and Maintenance of Offshore Cranes, Seventh Edition, December 2014. Global StandardsWhite Team
Definition(s)
White Team
A group responsible for refereeing an engagement between a Red Team of mock attackers and a Blue Team of actual defenders of information systems. Adapted from: CNSSI 4009. Source: NICCS™ Portal Cybersecurity Lexicon, National Initiative for Cybersecurity Careers and Studies (https://niccs.us-cert.gov/glossary) as of 11 November 2015, Global StandardsWhitelist
Definition(s)
Whitelist
A list of entities that are considered trustworthy and are granted access or privileges. Source: NICCS™ Portal Cybersecurity Lexicon, National Initiative for Cybersecurity Careers and Studies (https://niccs.us-cert.gov/glossary) as of 11 November 2015, Global StandardsWHP
Definition(s)
WHP
Wellhead pressure. Source: API RP 17A, Design and Operation of Subsea Production Systems—General Requirements and Recommendations, Fourth Edition, Reaffirmed 2011. Global Standards Source: NOGEPA Industrial Guideline No. 44, Standards and Acceptance Guidelines, Enhance QA/QC for Critical Well Components, Netherlands, Version 0, July 2011. Global StandardsWIF
Definition(s)
WIF
Well Integrity Forum. Source: 117 OLF, Norwegian Oil and Gas Association recommended guidelines for Well Integrity, No. 117, Revision No. 4, June 2011. Global StandardsWIM
Definition(s)
WIM
Well Integrity Management. Source: 117 OLF, Norwegian Oil and Gas Association recommended guidelines for Well Integrity, No. 117, Revision No. 4, June 2011. Global StandardsWIMS
Definition(s)
WIMS
Well integrity management system. Source: ISO 16530-1:2017, Petroleum and natural gas industries — Well integrity – Part 1: Life cycle governance, First Edition, March 2017. Global StandardsWind Spectrum
Definition(s)
Wind Spectrum
Measure of the variance associated with the fluctuating wind speed per unit frequency band. NOTE 1 The wind spectrum is an expression of the dynamic properties of the wind (turbulence). It reflects the fluctuations about and in the same direction as a certain mean wind speed, usually the 1 h sustained wind speed. There is hence no direction variable associated with the wind spectrum within this document. NOTE 2 As the sustained wind speed varies with elevation, the wind spectrum is a function of elevation. Source: API RP 2MET, Derivation of Metocean Design and Operating Conditions, First Edition, November 2014. Global StandardsWinding Angle
Definition(s)
Winding Angle
Shock load or high-pressure surge caused by sudden halting of flow in a pipeline or piping system. Source: ISO 14692-1:2017, Petroleum and natural gas industries — Glass-reinforced plastics (GRP) piping — Part 1: Vocabulary, symbols, applications and materials, Second Edition, August 2017. Global StandardsWindshield
Definition(s)
Windshield
Device used to protect the downwind side of an elevated flare burner from direct flame impingement.- NOTE: Windshields are also integral to the design of pilots to avoid flame-outs due to high winds.
Windshield
Device used to protect the outside of a flare burner from direct flame impingement.- NOTE: The windshield is so named because external flame impingement occurs on the downwind side of an elevated flare burner.