Glossary
Browse the IADC Lexicon alphabetically or by category. Get comprehensive definitions of drilling industry terms.
“D” Circle
Definition(s)
"D" Circle
A circle, usually imaginary unless the helideck itself is circular, the diameter of which is the “D” value of the largest helicopter the helideck is intended to serve. Source: NOGEPA Guideline 14, Helideck Operations and Procedures Manual, Netherlands, Version 2, December 2011. Global Standards(FES) Fire and Explosion Strategy
Definition(s)
(FES) Fire and Explosion Strategy
Results of the process that uses information from the fire and explosion evaluation to determine the measures required to manage these hazardous events and the role of these measures. 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 Standards(Normal) Towing
Definition(s)
(Normal) Towing
Drawing or pulling the unit by a chain or line using a tug boat.Normally towing is performed for units without any propulsion for (re-)location (compare with emergency towing). Source: Rules for Classification – Offshore units, DNVGL-OU-0101, Offshore drilling and support units, DNV GL, July 2015. Global Standards1
Definition(s)
1
Liters. Source: API SPEC 16C, Specification for Choke and Kill Systems, First Edition, January 1993 (Reaffirmed 2001). Global Standards150° Sector
Definition(s)
150° Sector
Obstructed Sector of a helideck / Limited obstacle sector. (= LOS). Source: NOGEPA Guideline 14, Helideck Operations and Procedures Manual, Netherlands, Version 2, December 2011. Global Standards180° Sector
Definition(s)
180° Sector
Vertical Obstacle free Sector of a helideck. Source: NOGEPA Guideline 14, Helideck Operations and Procedures Manual, Netherlands, Version 2, December 2011. Global Standards1988 LL Protocol
Definition(s)
1988 LL Protocol
1988 LL Protocol means the Protocol of 1988 relating to the International Convention on Load Lines, 1966, as amended. Source: IMO Resolution A.1023(26), Code for the Construction and Equipment of Mobile Offshore Drilling Units (2009 MODU Code), 2009. Global Standards210° Sector
Definition(s)
210° Sector
Obstacle free Sector of a helideck. (= OFS). Source: NOGEPA Guideline 14, Helideck Operations and Procedures Manual, Netherlands, Version 2, December 2011. Global Standards21st Century Security Strategy
Definition(s)
21st Century Security Strategy
The combined physical and logical/cyber governance strategies (principles, policies and controls) designed to safeguard the organization's assets, including its workforce, facilities, operations, equipment, technology, systems, communications, and information against threats and potential security events and to comply with regulatory frameworks.
Source: API RP 781 Security Plan Methodology for the Oil and Natural Gas Industries.1st Ed. September 2016. Global Standards
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Definition(s)
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Less than. Source: API SPEC 16C, Specification for Choke and Kill Systems, First Edition, January 1993 (Reaffirmed 2001). Global Standards>
Definition(s)
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Greater than. Source: API SPEC 16C, Specification for Choke and Kill Systems, First Edition, January 1993 (Reaffirmed 2001). Global StandardsA
Definition(s)
A
Shackle jaw width.
Source: API Standard 2CCU, Offshore Cargo Carrying Units, First Edition, August 2017. Global StandardsA
Cross-sectional area. Source: API Technical Report 17TR7, Verification and Validation of Subsea Connectors, First Edition, April 2017. Global StandardsA
Spudcan maximum cross sectional area.
Source: ABS Guidance Notes on Geotechnical Performance of Spudcan Foundations, January 2017. Global StandardsA
Activity. Source: NOGEPA Industrial Guideline No. 16, Working with Naturally Occurring Radioactive Materials (NORM), Netherlands, Version 1, January 2009. Global StandardsA-annulus
Definition(s)
A-annulus
Designation of the annulus between production tubing and production casing. [SOURCE: API RP 90, modified]. Source: ISO 16530-1:2017, Petroleum and natural gas industries - Well integrity – Part 1: Life cycle governance, First Edition, March 2017. Global Standards“A” annulus
Annulus between the production tubing and production casing. Source: API RP 96, Deepwater Well Design and Construction, First Edition, March 2013. Global Standards“A” annulus
The annulus designation between the production tubing and production casing. Source: API RP 90, Annular Casing Pressure Management for Offshore Wells, Upstream Segment. First Edition, August 2006. Global StandardsA-annulus
Annuli between the tubing and the production casing. Source: NORSOK D-010, Well integrity in drilling and well operations, Rev. 3, August 2004. Global StandardsA-Scan
Definition(s)
A-Scan
Data presentation utilizing a horizontal base line that indicates distance, or time, and a vertical deflection from the base line that indicates amplitude. Source: API RP 5A5, Field Inspection of New Casing, Tubing, and Plain-end Drill Pipe, Reaffirmed August 2010. Global StandardsA-Scan
Ultrasonic instrument display where distance is represented on the horizontal axis and signal strength on the vertical axis. Source: API RP 7G-2, Recommended Practice for Inspection and Classification of Used Drill Stem Elements, First Edition, August 2009. Global StandardsA-Scan Display
Definition(s)
A-Scan Display
Ultrasonic instrument display in which the received signal is displayed as a vertical height or “pip” from the horizontal-sweep time trace, while the horizontal distance between two signals represents the material distance for time of travel between the two conditions causing the signals. Source: API SPEC 7-1, Specification for Rotary Drill Stem Elements, First Edition, March 2006 (Addendum April 2011). Global StandardsAa
Definition(s)
Aa
Area ratio.
Source: ABS Guidance Notes on Geotechnical Performance of Spudcan Foundations, January 2017. Global StandardsAAA
Definition(s)
AAA
Authentication, authorization and accounting. Source: DNVGL-RP-G108, Cyber security in the oil and gas industry based on IEC 62443, DNV GL, September 2017. Global StandardsAAV
Definition(s)
AAV
Annulus access valve. Source: API RP 17A, Design and Operation of Subsea Production Systems—General Requirements and Recommendations, Fourth Edition, Reaffirmed 2011. Global StandardsAB
Definition(s)
AB
Accommodation Block. 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 StandardsAbandoned-in-place
Definition(s)
Abandoned-in-place
Piping system, circuit or contiguous sections thereof meeting all of the following: has been decommissioned with no intention for future use; has been completely de-inventoried/purged of hydrocarbon/chemicals; and is physically disconnected (e.g. air-gapped) from all energy sources and/or other piping/equipment.
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 StandardsAbandonment
Definition(s)
Abandonment
Abandonment is characterised by the severance of ties between the shipowner and the seafarer. Abandonment occurs when the shipowner fails to fulfil certain fundamental obligations to the seafarer relating to timely repatriation and payment of outstanding remuneration and to provision of the basic necessities of life, inter alia, adequate food, accommodation and medical care. Abandonment will have occurred when the master of the ship has been left without any financial means in respect of ship operation. Source: IMO Resolution A.930(22), Guidelines on Provision of Financial Security in Case of Abandonment of Seafarers, 17 December 2001, International Maritime Organization. Regulatory GuidanceAbandonment
Act of personnel onboard leaving an installation in an emergency. 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 Standards Source: ISO 15544:2000, Petroleum and natural gas industries – Offshore production installations – Requirements and guidelines for emergency. Global StandardsAbandonment
Abandon, in relation to a well, means to seal the well in order to render it permanently inoperative, and abandonment has a corresponding meaning. Source: Health and Safety in Employment (Petroleum Exploration and Extraction) Regulations 2013, SR 2013/208, New Zealand, as of May 2013. RegulationsAbility
Definition(s)
Ability
An individual’s knowledge, skills, abilities, and behavioral attributes that enable him or her to perform his or her work consistently, precisely, and reliably.
Source: International Association of Drilling Contractors, Competence Assurance-Guidelines for Building a Successful Program Revision April 2015. IADC GuidelinesAbility
capacity to perform an activity. Source: ISO/IEC TS 17027:2014, Conformity assessment – Vocabulary related to competence of persons used for certification of persons, Global StandardsAbnormal Level Earthquake
Definition(s)
Abnormal Level Earthquake
Intense earthquake of abnormal severity under the action of which the structure should not suffer complete loss of integrity.- NOTE: The ALE event is comparable to the abnormal event in the design of fixed structures which are described in API 2A-WSD and ISO 19903. When exposed to the ALE, a manned structure is supposed to maintain structural and/or floatation integrity for a sufficient period of time to enable evacuation to take place.
Abnormal Pressure
Definition(s)
Abnormal Pressure
Reservoir pore fluid pressure that is not similar to normal saltwater gradient pressure. The term is usually associated with higher than normal pressure, increased complexity for the well designer and an increased risk of well control problems. Abnormal pressure gradients exceed a 10-ppg equivalent fluid density (0.52 psi per foot). Gradients below normal are called subnormal. Source: IADC UBO / MPD Glossary, December 2011. Global StandardsAbnormal Pressure
Pore pressure in excess of that pressure resulting from the hydrostatic pressure exerted by a vertical column of water with salinity normal for the geographic area. Source: API RP 59, Recommended Practice for Well Control Operations, Second Edition, May 2006. Global StandardsAbnormal Pressure
Formation pore pressure in excess of that pressure resulting from the hydrostatic pressure exerted by a vertical column of water with salinity normal for the geographic area. Source: API RP 64, Recommended Practice for Diverter Systems Equipment and Operations, Second Edition, November 2001 (March 1, 2007). Global StandardsAbnormal Value
Definition(s)
Abnormal Value
Design value of a parameter of abnormal severity used in accidental limit state checks in which a structure is intended not to suffer complete loss of integrity.- NOTE: Abnormal events have probabilities of the order of 10−3 to 10−4 per year. In the limit state checks, some or all of the partial factors are set to 1.0.
Abnormal Value
Design value of a parameter of abnormal severity used in accidental limit state checks in which a structure is intended not to suffer complete loss of integrity.- Note: 1 to entry: Abnormal events are typically accidental and environmental (including seismic) events having probabilities of exceedance of the order of 10−3 to 10−4 per annum.
Abnormal Wave Crest
Definition(s)
Abnormal Wave Crest
Wave crest with probability of typically 10-3 to 10-4 per annum. Source: ISO 19905-1:202, Petroleum and natural gas industries – Site-specific assessment of mobile offshore units – Part 1: Jack-ups. Global StandardsABP
Definition(s)
ABP
Applied back pressure. Source: API Specification 16Q, Design, Selection, Operation, and Maintenance of Marine Drilling Riser Systems, Second Edition, April 2017. Global StandardsABS
Definition(s)
ABS
American Bureau of Shipping. Source: Rules for Classification and Construction, IV Industrial Services, 6 Offshore Technology, 9 Guideline for Personnel Transfers by Means of Lifting Appliances, Edition 2011, Germanischer Lloyd SE, Global Standards Source: International Association of Drilling Contractors, Appendix 2 to Health, Safety and Environment Case Guidelines for Offshore Drilling Contractors, Issue 3.3.2, February 2010. IADC Guidelines API RP 500, Recommended Practice for Classification of Locations for Electrical Installations at Petroleum Facilities Classified as Class I, Division 1 and Division 2, Third Edition, December 2012, Global Standards 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 StandardsABS Guidance
Definition(s)
qnet
Net cone resistance, which is the measured cone resistance being corrected for the pore pressure effects and the total in-situ vertical stress.
Source: ABS Guidance Notes on Geotechnical Performance of Spudcan Foundations, January 2017. Global Standards