Global Standards

Definition(s)

---

Wave Spectrum

measure of the amount of energy associated with the fluctuation of the sea surface elevation per unit frequency band and per unit directional sector. NOTE 1 The wave frequency spectrum (integrated over all directions) is often described by use of some parametric form such as the Pierson-Moskowitz or JONSWAP wave spectrum. NOTE 2 The area under the wave spectrum is the zeroth spectral moment m0, which is a measure of the total energy in the sea state; m0 is used in contemporary definitions of the significant wave height Source: API RP 2MET, Derivation of Metocean Design and Operating Conditions, First Edition, November 2014. Global Standards

Definition(s)

---

Wave Steepness

Characteristic of individual waves calculated as wave height divided by wave length. NOTE For periodic waves, the concept is straightforward as H/λ. For random waves, the definition is used with the significant wave height (H_s) and the wave length that corresponds with the peak period (T_p) of the wave spectrum in deep water. The significant wave steepness is then defined as H_s/λ_p = H_s / [(g/2π) T_p2] and is typically in the range of 1/16 to 1/20 for severe sea states. Source: API RP 2MET, Derivation of Metocean Design and Operating Conditions, First Edition, November 2014. Global Standards

Definition(s)

---

Wax

Wax is typically defined as the high molecular weight paraffins which become insoluble in crude due either to the loss of light ends and/or a decrease in the temperature of the crude. Wax consists of straight-chain, branched or cyclic paraffins with carbon numbers typically ranging between C15 and C70+. The melting point of the wax increases with increasing carbon number, while the solubility in crude oil decreases with increasing carbon number. Source: API RP 17A, Design and Operation of Subsea Production Systems—General Requirements and Recommendations, Fourth Edition, Reaffirmed 2011. Global Standards  

Definition(s)

---

Wax appearance temperature

The wax appearance temperature (WAT, also commonly known as the cloud point) is the temperature at which the first wax crystals form as the crude is cooled, while the pour point is the temperature below which the crude will no longer flow. Source: API RP 17A, Design and Operation of Subsea Production Systems—General Requirements and Recommendations, Fourth Edition, Reaffirmed 2011. Global Standards  

Definition(s)

---

WBE

One of several dependent components that are combined to form a well barrier. Source: ISO 16530-1:2017, Petroleum and natural gas industries — Well integrity – Part 1: Life cycle governance, First Edition, March 2017. Global Standards

WBE

Well Barrier Element. Source: ISO 16530-1:2017, Petroleum and natural gas industries — Well integrity – Part 1: Life cycle governance, First Edition, March 2017. Global Standards Source: 117 OLF, Norwegian Oil and Gas Association recommended guidelines for Well Integrity, No. 117, Revision No. 4, June 2011. Global Standards

Definition(s)

---

WCI

Wind shield index. Source: NORSOK D-001, Drilling facilities, Rev. 3, December 2012. Global Standards

Definition(s)

---

WCID

well construction interface document Source: API  Bulletin 97, Well Construction Interface Document Guidelines, First Edition, December 2013. Global Standards

Definition(s)

---

WCID-SEMS

well construction interface document – safety and environmental management system. Source: API  Bulletin 97, Well Construction Interface Document Guidelines, First Edition, December 2013. Global Standards

Definition(s)

---

WCID-well Plan

well construction interface document – well plan. Source: API  Bulletin 97, Well Construction Interface Document Guidelines, First Edition, December 2013. Global Standards

Definition(s)

---

WCT-BOP

Wireline/coiled tubing BOP. Source: API RP 17G, Recommended Practice for Completion/Workover Risers, Second Edition, July 2006 (Reaffirmed April 2011). Global Standards  

WCT-BOP

Wireline/coil tubing blowout preventer (see ISO 13628-7). 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 Standards

Definition(s)

---

WCTEC

Well Control Training, Examination and Certification. Source: OGP Report No. 476, Recommendations for enhancements to well control training, examination and certification, International Association of Oil & Gas Producers, October 2012. Global Standards  

Definition(s)

---

Weak Link

Device that is used to ensure that the umbilical parts or severs at a specified load and location. Source: API SPEC 17E, Specification for Subsea Umbilicals, Upstream Segment, Fourth Edition, October 2010. Global Standards  

Definition(s)

---

Weak Signal

A concept referring to the process of scanning for discontinuities, observations or pieces of data that may provide early warnings or signs of change. In an OMS context, weak signals can provide early indicators of potential safety, health, environmental, social or security issues, including unforeseen risks, control weaknesses or a degradation in performance. Source: IOGP Report No. 510, Operating Management System Framework for controlling risk and delivering high performance in the oil and gas industry, International Association of Oil & Gas Producers, June 2014. Global Standards

Definition(s)

---

Weakness

A shortcoming or imperfection in software code, design, architecture, or deployment that, under proper conditions, could become a vulnerability or contribute to the introduction of vulnerabilities. Adapted from: ITU-T X.1520 CWE, FY 2013 CIO FISMA Reporting Metrics. Source: NICCS™ Portal Cybersecurity Lexicon, National Initiative for Cybersecurity Careers and Studies (https://niccs.us-cert.gov/glossary) as of 11 November 2015, Global Standards

Definition(s)

---

Wear Allowance

Amount of wall thickness added to the pipe or component to allow for corrosion/erosion/wear. Source: API Standard 2RD, Dynamic Risers for Floating Production Systems, Second Edition, September 2013. Global Standards

Definition(s)

---

Wear Bushing

Bushing to be installed in the rotary table, to provide a smooth lateral support to the workover riser at drill floor level. Source: API RP 17G, Recommended Practice for Completion/Workover Risers, Second Edition, July 2006 (Reaffirmed April 2011). Global Standards  

Wear Bushing

Retrievable cylindrical device that protects the internal surfaces of wellhead equipment and the top of the last casing suspended. Source: API SPEC 6A, Specification for Wellhead and Christmas Tree Equipment, Twentieth Edition, October 2010 (Addendum November 2012). Global Standards  

Wear Bushing

Bore protector that also protects the casing hanger below it. 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 Standards

Definition(s)

---

Weathervaning

Process by which a floating structure passively varies its heading in response to time-varying environmental actions. Source: ISO 19901-7:2013, Petroleum and natural gas industries – Specific requirements for offshore structures – Part 7: Stationkeeping systems for floating offshore structures and mobile offshore units. Global Standards

Definition(s)

---

WEC

Wells Expert Committee. Source: OGP Report No. 476, Recommendations for enhancements to well control training, examination and certification, International Association of Oil & Gas Producers, October 2012. Global Standards  

Definition(s)

---

Wedged Socket

A termination generally consisting of a tapered socket into which the rope is inserted with separated strands and broomed out yarns and then secured by a tapered wedge-like device set and driven into the center of the yarns. Source: API RP 2SM Design, Manufacture, Installation, and Maintenance of Synthetic Fiber Ropes for Offshore Mooring, Second Edition, July 2014. Global Standards Source: API RP 2SM, Design, Manufacture, Installation, and Maintenance of Synthetic Fiber Ropes for Offshore Mooring, First Edition, July 2014. Global Standards

Definition(s)

---

Weigh Batch Mixer (or Scale Tank)

Device or system for the weighing and blending of cement with dry additives. Source: API RP 10B-2, Recommended Practice for Testing Well Cements, First Edition, July 2005 (Reaffirmed: July 2010). Global Standards

Definition(s)

---

Weight

Measure of gravitational force on an object. Source: IADC UBO / MPD Glossary, December 2011. Global Standards

Definition(s)

---

Weight Code

Unique numerical code for each outside diameter of drill pipe, normally stamped on the pin base and in the mill slot, which provides wall thickness and pipe body mass per unit length information. Source: API RP 7G-2, Recommended Practice for Inspection and Classification of Used Drill Stem Elements, First Edition, August 2009. Global Standards

Definition(s)

---

Weight Cut

The amount by which drilling fluid density is reduced by entrained formation fluids or air. Source: API RP 59, Recommended Practice for Well Control Operations, Second Edition, May 2006. Global Standards  

Weight Cut

Drilling fluid density reduction by entrained fluids. Source: IADC UBO / MPD Glossary, December 2011. Global Standards

Definition(s)

---

Weight in Water

Submerged weight including content minus buoyancy. Source: API RP 17G, Recommended Practice for Completion/Workover Risers, Second Edition, July 2006 (Reaffirmed April 2011). Global Standards

Definition(s)

---

Weight of One fully Kitted Person (including luggage/ tools)

100 kg, to be used for establishing the live load (LL) of the gangway. Source: Offshore Gangways, DNVGL-ST-0358, DNV GL, September 2017. Global Standards

Definition(s)

---

Weighted Drilling Fluid

Drilling fluid to which high specific-gravity solids have been added to increase its density. Source: API RP 13C, Recommended Practice on Drilling Fluids Processing Systems Evaluation, Upstream Segment, Fourth Edition, December 2010. Global Standards

Definition(s)

---

Weighting Material

High specific-gravity solids used to increase the density of drilling fluids. NOTE This material is commonly barite or haematite, and in special applications may be limestone. Source: API RP 13C, Recommended Practice on Drilling Fluids Processing Systems Evaluation, Upstream Segment, Fourth Edition, December 2010. Global Standards

Definition(s)

---

Weld Groove

Area between two metals to be joined that has been prepared to receive weld filler metal. Source: API SPEC 16A, Specification for Drill-through Equipment, Third Edition, June 2004 (Errata/Supplement November 2004). Global Standards  

Weld Groove

An area between two metals to be joined that has been prepared to receive weld filler metal. Source: API SPEC 16C, Specification for Choke and Kill Systems, First Edition, January 1993 (Reaffirmed 2001). Global Standards Source: API SPEC 16RCD, Specification for Drill Through Equipment—Rotating Control Devices, Upstream Segment, First Edition, February 2005. Global Standards  

Weld Groove (weld prep)

Area between two metals to be joined that has been prepared to receive weld filler metal; also known as “weld prep” 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 Standards