Glossary
Browse the IADC Lexicon alphabetically or by category. Get comprehensive definitions of drilling industry terms.
Quenched and Tempered
Definition(s)
Quenched and Tempered
Quench hardening - Hardening a ferrous alloy by austenitizing and then cooling rapidly enough so that some or all of the austenite transforms to martensite. Tempering - Reheating a quenched-hardened or normalized ferrous alloy to a temperature below the transformation range and then cooling at any rate desired. Source: API RP 7G, Recommended Practice for Drill Stem Design and Operating Limits, Upstream Segment, Sixteenth Edition, August 1998 (Addendum 2: September 2009). Global StandardsQuenching
Definition(s)
Quenching
Cooling of a fluid by mixing it with another fluid of a lower temperature. Source: API STD 521, Pressure-relieving and Depressuring Systems, Sixth Edition, January 2014. Global Standards Source: API STD 521, Pressure-relieving and Depressuring Systems, Fifth Edition, January 2007 (Addendum May 2008). Global StandardsQuick Opening Valve Flow Characteristic
Definition(s)
Quick Opening Valve Flow Characteristic
Produces a very rapid increase in flow between the closed position and the partially open position. Source: IADC UBO / MPD Glossary, December 2011. Global StandardsQv
Definition(s)
Qv
Ultimate vertical bearing capacity of the spudcan foundation .
Source: ABS Guidance Notes on Geotechnical Performance of Spudcan Foundations, January 2017. Global StandardsQwner/user Inspector
Definition(s)
Qwner/user Inspector
An authorized inspector employed by an owner/user who has qualified by examination under the provisions of Section 4 and Annex A.
Source: API 570, Piping Inspection Code: In-service Inspection, Rating, Repair, and Alteration of Piping Systems, Fourth Edition, February 2016, with Addendum May 2017. Global StandardsR
Definition(s)
R
Radius of the circular footing.
Source: ABS Guidance Notes on Geotechnical Performance of Spudcan Foundations, January 2017. Global Standardsr
Shear strength ratio.
Source: ABS Guidance Notes on Geotechnical Performance of Spudcan Foundations, January 2017. Global StandardsR-ratio
Definition(s)
R-ratio
ratio of the hoop stress to the axial stress in a particular test condition- EXAMPLE: In a hydrostatic test condition where a) the test sample is unrestrained, b) the hoop stress component is represented by half the pressure times diameter divided by wall thickness (PD/2t) and c) the axial stress component is represented by one-fourth the pressure times diameter divided by wall thickness (PD/4t), the R-ratio would be exactly 2,0. In the same test condition, if the axial stress component is represented by force over area (F/A) instead of PD/4t, the R-ratio will most likely be slightly higher than 2,0.
- Note: 1 to entry: Data points on the long term envelope (3.2.70), threshold envelope (3.2.117) and design envelope (3.2.15) can be referred to as R = x or Rx or x:y data points where x and y are integers (e.g. R = 2, R2 or 2:1) and/or real numbers (R = 0,7, R0,7 or 0,7:1). In some cases, the x value can be an approximation of the R-ratio.
R/Min
Definition(s)
R/Min
Revolutions per minute. Source: API RP 5C5, Recommended Practice on Procedures for Testing Casing and Tubing Connections, Third Edition, July 2003 (Reaffirmed August 2010). Global StandardsR/T
Definition(s)
R/T
Radio Telephony. Source: NOGEPA Guideline 14, Helideck Operations and Procedures Manual, Netherlands, Version 2, December 2011. Global StandardsRA
Definition(s)
Ra
Surface finish Source: API Specification 16A, Specification for Drill-through Equipment, Fourth Edition, April 2017. Global StandardsRa
Measurement of the average roughness of a surface. Source: API Specification 16A, Specification for Drill-through Equipment, Fourth Edition, April 2017. Global StandardsRA
Component of a JSA, where a determination of the expected level (severity) of illness, injury, and/or property damage that an identified hazard can cause is coupled with the frequency (probability) of that level of hazard occurring.- NOTE: 1 This is then plotted on a matrix to determine the level of risk associated with that job.
- NOTE: 2 If the level of risk is not acceptable, control measures are introduced to reduce the risk to an acceptable level.
RA
Risk assessment. Source: API RP 98, Personal Protective Equipment Selection for Oil Spill Responders, First Edition, August 2013. Global StandardsRA
Reliability and availability. Source: API STD 689, Collection and Exchange of Reliability and Maintenance Data for Equipment, First Edition, July 2007. Global StandardsRa
Definition(s)
Ra
Radium. Source: NOGEPA Industrial Guideline No. 16, Working with Naturally Occurring Radioactive Materials (NORM), Netherlands, Version 1, January 2009. Global StandardsRabbit
Definition(s)
Rabbit
An instrument or device that is dropped, pulled, or pushed through a section of pipe to ensure that it is free of obstruction. Source: API RP 54, Recommended Practice for Occupational Safety for Oil and Gas Well Drilling and Servicing Operations, Third Edition, August 1999 (2007). Global StandardsRACI
Definition(s)
RACI
Responsible, Accountable, Consulted, Informed. Source: ISO 16530-1:2017, Petroleum and natural gas industries — Well integrity – Part 1: Life cycle governance, First Edition, March 2017. Global StandardsRack Phase Difference
Definition(s)
Rack Phase Difference
The difference in elevations between the chords of any one leg.
Source: ABS Guidance Notes on Geotechnical Performance of Spudcan Foundations, January 2017. Global StandardsRack Phase Difference
Relative difference in the position of adjacent leg chords within a leg measured parallel to the longitudinal axis of the chords. NOTE This is the out-of-plane distortion of the plan-frame. Source: ISO 19905-1:202, Petroleum and natural gas industries – Site-specific assessment of mobile offshore units – Part 1: Jack-ups. Global StandardsRacking Pipe or Rods
Definition(s)
Racking pipe or rods
Act of placing stands of pipe or rods in an orderly arrangement in the derrick. Source: API RP 54, Recommended Practice for Occupational Safety for Oil and Gas Well Drilling and Servicing Operations, Third Edition, August 1999 (2007). Global StandardsRadiation Intensity
Definition(s)
Radiation Intensity
Local radiant heat transfer rate from the flare flame, usually considered at grade level. Source: API STD 521, Pressure-relieving and Depressuring Systems, Sixth Edition, January 2014. Global Standards Source: API STD 521, Pressure-relieving and Depressuring Systems, Fifth Edition, January 2007 (Addendum May 2008). Global StandardsRadio Watch
Definition(s)
Radio Watch
the period during which a member of the complement is required to be at, and in charge of, the radio communication equipment. Source: Atlantic Canada Offshore Petroleum Industry, Standard Practice for the Training and Qualifications of Personnel, 2013, Canadian Association of Petroleum Producers, Global StandardsRadioisotope
Definition(s)
Radioisotope
Unstable isotope of an element that disintegrates spontaneously, emitting radiation. Source: API RP 5A5, Field Inspection of New Casing, Tubing, and Plain-end Drill Pipe, Reaffirmed August 2010. Global StandardsRAL
Definition(s)
RAL
“Reichsausschuss für Lieferbedingungen”, a Colour system used by German paint manufacturers. Source: API RP 17A, Design and Operation of Subsea Production Systems—General Requirements and Recommendations, Fourth Edition, Reaffirmed 2011. Global StandardsRam Blowout Preventer
Definition(s)
Ram blowout preventer
Blowout preventer that uses metal blocks assembled with elastomer seals to seal off pressure on a wellbore, with or without tubulars in the bore. 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 StandardsRam blowout preventer
Blowout preventer that uses two opposing metal elements (rams) with integral elastomer seals to contain pressure within a wellbore. NOTE Rams may be designed to close on a specific pipe size (fixed pipe rams), a range of pipe sizes (variable bore rams), or open hole (blind or blind/shear rams). Source: API RP 96, Deepwater Well Design and Construction, First Edition, March 2013. Global StandardsRam blowout preventer
Blowout preventer that uses metal blocks with integral elastomer seals to seal off pressure on a wellbore with or without tubulars in the bore. Source: API SPEC 16A, Specification for Drill-through Equipment, Third Edition, June 2004 (Errata/Supplement November 2004). Global StandardsRam BOP
Definition(s)
Ram BOP
Blowout preventer that uses metal blocks assembled with elastomer seals to seal off pressure on a wellbore with or without tubulars in the bore.
Source: API STANDARD 16AR, Standard for Repair and Remanufacture of Drill-through Equipment, First Edition, April 2017. Global StandardsRam BOP
A blowout preventer that uses rams to seal off pressure in the wellbore. Source: API SPEC 16D, Specification for Control Systems for Drilling Well Control Equipment and Control Systems for Diverter Equipment, Upstream Segment, Second Edition, July 2004. Global StandardsRAM(S)
Definition(s)
RAM(S)
Reliability, availability, maintainability (and safety). Source: API STD 689, Collection and Exchange of Reliability and Maintenance Data for Equipment, First Edition, July 2007. Global StandardsRamping
Definition(s)
Ramping
- Gradual startup or shutdown of a pump unit.
- Modeling term meaning to change variables with time.
Random Failure
Definition(s)
Random Failure
failure, occurring in a random way Note 1 to entry: A random failure may be time or demand dependent. Whether it occurs or not is not predictable with certainty but the corresponding failure rate (see 3.1.18) or probability of a failure due to demand (see 3.2.13) may be predictable and this allows probabilistic calculations. EXAMPLE Examples of failure mechanisms leading to unpredictable failure occurrence are: hardware random failures resulting from degradation mechanisms; human random failure resulting from error in routine operation, lack of attention, stress, tiredness, etc Note 2 to entry: From the probabilistic point of view, the random failures are the contrary of systematic failures (see 3.2.17) which occur in a deterministic way (i.e. with a probability equal to 1) when some conditions are met. Source: ISO/TR 12489:2013(E) Reliability modelling and calculation of safety systems. Global StandardsRange
Definition(s)
Range
A length classification for API Oil Country Tubular Goods. Source: API RP 7G, Recommended Practice for Drill Stem Design and Operating Limits, Upstream Segment, Sixteenth Edition, August 1998 (Addendum 2: September 2009). Global StandardsRankine
Definition(s)
Rankine
(degrees temperature) - English measurement of absolute temperature (+459.69 offset). Source: IADC UBO / MPD Glossary, December 2011. Global StandardsRAO
Definition(s)
RAO
Ratio of a vessel’s motion to the wave amplitude causing that motion and presented over a wide range of wave periods.
Source: API Specification 16Q, Design, Selection, Operation, and Maintenance of Marine Drilling Riser Systems, Second Edition, April 2017. Global Standards