Glossary
Browse the IADC Lexicon alphabetically or by category. Get comprehensive definitions of drilling industry terms.
Active Attack
Definition(s)
Active Attack
An actual assault perpetrated by an intentional threat source that attempts to alter a system, its resources, its data, or its operations. Adapted from: IETF RFC 4949, NIST SP 800-63 Rev 1 Source: NICCS™ Portal Cybersecurity Lexicon, National Initiative for Cybersecurity Careers and Studies (https://niccs.us-cert.gov/glossary) as of 11 November 2015, Global StandardsActive Barriers
Definition(s)
Active barriers
Active barriers are typically barriers that are designed to be routinely actuated either manually (e.g. by a diver or ROV) or by some form of remote control (e.g. via the production control system) or by reverse flow (e.g. check valves), such as the following: downhole SCSSVs and SSCSVs; subsea tree valves (including valves in the production and annulus flow paths, as well as valves in hydraulic and chemical injection lines); manifold valves (including hydraulically actuated and ROV-operated valves); flowline isolation valves (including those on a manifold, as well as at the top of a riser); check valves (including those in downhole gaslift valves and in chemical injection lines). Barriers such as downhole sliding sleeves can be classified as either passive or active, depending on the activation method and the anticipated activation frequency. Source: API RP 17A, Design and Operation of Subsea Production Systems—General Requirements and Recommendations, Fourth Edition, Reaffirmed 2011. Global StandardsActive Content
Definition(s)
Active Content
Software that is able to automatically carry out or trigger actions without the explicit intervention of a user. 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 StandardsActive Data
Definition(s)
Active Data
continually updated data, based on latest operational data.. Source: IADC UBO / MPD Glossary, December 2011. Global StandardsActive Fire Protection
Definition(s)
Active Fire Protection
Method of extinguishing fire by application of substances such as halon, water, carbon dioxide, foam, etc.
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 StandardsActive Maintenance Time
Definition(s)
Active Maintenance Time
That part of the maintenance time during which a maintenance action is performed on an item, either automatically or manually, excluding logistic delays. NOTE 1 A maintenance action can be carried out while the item is performing a required function. NOTE 2 For a more detailed description and interpretation of maintenance times, see Figure 4 and Annex C. Source: API STD 2000, Venting Atmospheric and Low-pressure Storage Tanks, Sixth Edition, November 2009. Global StandardsActive Monitoring Systems
Definition(s)
Active Monitoring Systems
Active monitoring systems: • Measure the achievement of objectives and specified standards; • Concentrate on high-risk activities by monitoring in more depth and more frequently. Source: Approved Code of Practice for Managing Hazards to Prevent Major Industrial Accidents, Health and Safety in Employment Act 1992, Department of Labour, New Zealand, July 1994. Regulatory GuidanceActive Seal Relaxed Diameter
Definition(s)
Active Seal Relaxed Diameter
The inside diameter through the active packing element when in the fully open condition (no hydraulic closing pressure applied and after closing to manufacturers minimum specified diameter). Source: API SPEC 16RCD, Specification for Drill Through Equipment—Rotating Control Devices, Upstream Segment, First Edition, February 2005. Global StandardsActively Engaged as an Inspector
Definition(s)
Actively engaged as an inspector
"Actively engaged as an inspector" shall be defined by one of the following provisions:- A minimum of 20% of time spent performing inspection activities or supervision inspection activities as described in the API 510 inspection code over the most recent three-year certification period.
- Performance of inspection activities or supervision of inspection activities on 75 pressure vessels as described in API 510 over the most recent three-year certification period.
- Note: Inspection activities common to other API inspection documents (NDE, record-keeping, review of welding documents, etc.) may be considered here.
Activity
Definition(s)
Activity
Defined work of an asset, business or company that results in specific, measurable outputs. "Activities" in this guidance is a general term that may include individual tasks or groups of tasks, or it may define entire operations, initiatives or projects of the company. For the petroleum sector, example activities at the company level include oil and gas exploration, drilling, production, and processing, refining, and transport and marketing of products. Activities should also be considered for all periods of the asset or business lifecycle – for example, construction and decommissioning projects. 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 StandardsActivity
“Activity” includes, unless the context otherwise requires, a diving project and standing a vessel by. Source: The Health and Safety at Work etc. Act 1974 (Application outside Great Britain) Order 2001, UK S.I. 2013/214, 2013. RegulationsActivity
Activity means a petroleum activity or a greenhouse gas activity. Source: Offshore Petroleum and Greenhouse Gas Storage (Environment) Regulations 2009 (Statutory Rules 1999 No. 228 as amended), Australia, prepared on 1 January 2012. RegulationsActivity
A reference in these Regulations to an activity includes, where the context permits, a reference to:- a proposed activity; and
- any stage of an activity.
Activity
Work to be carried out as part of a process characterized by a set of specific inputs and tasks that produce a set of outputs to meet customer requirements. 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 GuidelinesActivity
Preparation for and implementation of operations. Source: NORSOK D-010, Well integrity in drilling and well operations, Rev. 3, August 2004. Global StandardsActuator
Definition(s)
Actuator
Mechanism for the manual, remote, or automatic operation of a valve or choke.
Source: API Specification 16Q, Design, Selection, Operation, and Maintenance of Marine Drilling Riser Systems, Second Edition, April 2017. Global StandardsActuator
Mechanism for the remote or automatic operation of a valve or choke. Source: API SPEC 6A, Specification for Wellhead and Christmas Tree Equipment, Twentieth Edition, October 2010 (Addendum November 2012). Global Standards Source: API SPEC 16C, Specification for Choke and Kill Systems, First Edition, January 1993 (Reaffirmed 2001). Global StandardsActuator
A mechanism for the remote or automatic operation of a valve or choke. 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 Standards Source: API RP 16Q, Recommended Practice for Design, Selection, Operation and Maintenance of Marine Drilling Riser Systems, First Edition, November 1993 (Reaffirmed August 2001). Global StandardsActuator
A device used to open or close a valve by means of applied manual, hydraulic, pneumatic, or electrical energy. Source: API RP 64, Recommended Practice for Diverter Systems Equipment and Operations, Second Edition, November 2001 (March 1, 2007). Global StandardsActuators
Definition(s)
Actuators
Part of a control system, which regulates speed, power, valve position, etc. to match a set point. Source: IADC UBO / MPD Glossary, December 2011. Global StandardsAcute Hazard
Definition(s)
Acute Hazard
Capable of causing effects occurring from exposure over a short time, usually within minutes or hours. An acute exposure can result in short-term or long-term health effects. Source: API RP 2009, Safe Welding, Cutting, and Hot Work Practices in the Petroleum and Petrochemical Industries, Seventh Edition, February 2002 (Reaffirmed, March 2012), Global Standards Source: API RP 2201, Safe Hot Tapping Practices in the Petroleum & Petrochemical Industries, Fifth Edition, July 2003 (Reaffirmed October 2010), Global StandardsAcute Release
Definition(s)
Acute release
Tier 1 and 2 both apply the concept of an acute release to differentiate a PSE from other LOPCs which occur over a prolonged period (such as fugitive emissions) and are unlikely to constitute a major incident risk of a fire or explosion. An acute release of material is defined as LOPC which exceeds the reporting threshold for a Tier 1 or Tier 2 PSE within any period of one hour during the event. Acute releases include but are not limited to equipment and piping failures due to corrosion, overpressure, damage from mobile equipment, sabotage, etc. For example: valves being left open; tanks being overfilled; flare or relief systems not operating as intended; process upsets or errors that result in process materials entering other process containment systems with no provisions or design considerations; corrosion of a pipe or a gasket failure where the release over an hour exceeds thresholds. Source: OGP Report No. 456, Process Safety – Recommended Practice on Key Performance Indicators, International Association of Oil & Gas Producers, November 2011. Global StandardsAD
Definition(s)
AD
Active directory.Source: DNVGL-RP-G108, Cyber security in the oil and gas industry based on IEC 62443, DNV GL, September 2017. Global Standards
Adapter
Definition(s)
Adapter
Pressure-containing piece of equipment having end connections of different nominal sizes and/or pressure ratings, used to connect other pieces of equipment of different nominal sizes and/or pressure ratings. Source: API STANDARD 16AR, Standard for Repair and Remanufacture of Drill-through Equipment, First Edition, April 2017. Global Standards Source: API Specification 16A, Specification for Drill-through Equipment, Fourth Edition, April 2017. Global Standards Source: API SPEC 6A, Specification for Wellhead and Christmas Tree Equipment, Twentieth Edition, October 2010 (Addendum November 2012). Global StandardsAdapter
Pressure-containing piece of equipment having end connections of different nominal size designation and/or pressure rating. Source: API SPEC 16A, Specification for Drill-through Equipment, Third Edition, June 2004 (Errata/Supplement November 2004). Global StandardsAdapter Spool
Definition(s)
Adapter Spool
A spool used to connect drill-through equipment with different end connections, nominal size designation and/or pressure ratings to each other. Source: API STD 53, Blowout Prevention Equipment Systems for Drilling Wells, Upstream Segment, Fourth Edition, November 2012. Global StandardsAdapter Spool
Connects blowout preventers of different sizes or pressure ratings to the casing head. Source: IADC UBO / MPD Glossary, December 2011. Global StandardsAddition Section
Definition(s)
Addition Section
Compartment(s) in the surface drilling fluid system between the removal section and the suction section which provides a well-agitated compartment(s) for the addition of commercial products such as chemicals, necessary solids and liquids. Source: API RP 13C, Recommended Practice on Drilling Fluids Processing Systems Evaluation, Upstream Segment, Fourth Edition, December 2010. Global StandardsAdditive
Definition(s)
Additive
Any chemical substance or combination of substances, including a proppant, contained in a hydraulic fracturing fluid that is intentionally added to a base fluid for a specific purpose whether or not the purpose of any such substance or combination of substances is to create fractures in a formation. Source: Oil and Gas Division, Texas Administrative Code, Title 16, Chapter 3, February 2013. RegulationsAdditive
Material added to a cement slurry to modify or enhance some desired property.- NOTE: Properties that are commonly modified include setting time (by use of retarders or accelerators), fluid loss, viscosity, etc.
Additive
Material added to a cement slurry to modify or enhance some desired property.- NOTE: Common properties that are modified include: setting time (by use of retarders or accelerators), fluid loss control, viscosity, etc.
ADELT
Definition(s)
ADELT
Automatically Deployable Emergency Locator Transmitter. Source: NOGEPA Guideline 14, Helideck Operations and Procedures Manual, Netherlands, Version 2, December 2011. Global StandardsAdequate Ventilation
Definition(s)
Adequate Ventilation
Adequate ventilation is defined as ventilation (natural or artificial) that is sufficient to prevent the accumulation of significant quantities of vapor-air or gas-air mixtures in concentration above 25 % of their lower flammable (explosive) limit, LFL (LEL). 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 StandardsAdequately Ventilated Area
Definition(s)
Adequately Ventilated Area
Is an area having a natural or artificial ventilation system to prevent the accumulation of gases to an explosive level. API Recommends 12 air volume changes per hour or 1.5 CFM per square foot of floor area whichever is greater. Source: IADC UBO / MPD Glossary, December 2011. Global StandardsAdhesive Bond
Definition(s)
Adhesive Bond
Rigid type of joint between two components made using an adhesive- Note: 1 to entry: An adhesive joint generally consists of a slightly conical (tapered) bell end and a machined (cylindrical or tapered) spigot end.
Adhesive Joint
Definition(s)
Adhesive Joint
Rigid type of joint between two components made using an adhesive.- Note: 1 to entry: An adhesive joint generally consists of a slightly conical (tapered) bell end and a machined (cylindrical or tapered) spigot end.
Adiabatic
Definition(s)
Adiabatic
Process that is at constant temperature without loss or gain of heat. Source: IADC UBO / MPD Glossary, December 2011. Global StandardsAdiabatic Efficiency
Definition(s)
Adiabatic Efficiency
Ratio of theoretical temperature increase to actual temperature increase; a measure of the work done by a compressor that is not lost as heat. Source: IADC UBO / MPD Glossary, December 2011. Global StandardsAdjustable Choke
Definition(s)
Adjustable Choke
A choke with a conical needle and seat vary the rate of flow. See also chokes. Source: IADC UBO / MPD Glossary, December 2011. Global StandardsAdjustable Frequency Controller
Definition(s)
Adjustable frequency controller or AFC
A device that is used to control the speed of an AC motor by varying the frequency of the voltage supplied to it. These are also known as adjustable speed drives, variable frequency drives, adjustable frequency drives and other, similar, names. 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 StandardsAdjustable Speed Drive
Definition(s)
Adjustable Speed Drive
TA device that is used to control the speed of an AC motor by varying the frequency of the voltage supplied to it. These are also known as variable frequency drives, adjustable frequency drives and other, similar, names.
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 Standards