Glossary
Browse the IADC Lexicon alphabetically or by category. Get comprehensive definitions of drilling industry terms.
Gas Production, Gross Operated
Definition(s)
Gas production, gross operated
This value is the annual gross operated production of gas on the OCS by an operator in millions of barrels. Source: API RP 75, Recommended Practice for Development of a Safety and Environmental Management Program for Offshore Operations and Facilities: Upstream Segment, Third Edition, May 2004. Global StandardsGas, Protective
Definition(s)
Gas, protective
The gas used for pressurization or for the dilution of flammable gases to a level well below their lower explosive limit, usually below 25% LFL/LEL. The protective gas may be air, nitrogen, other nonflammable gas, or a mixture of such gases. 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 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 StandardsGas-Lift Mandrel
Definition(s)
Gas-Lift Mandrel
A gas-lift system assembled with the production tubing string to provide a means of deploying gas-lift valves. The position or depth of the gas lift valves is crucial to the efficient operation of the entire system. Consequently, proper assembly of the gas lift mandrels within the completion tubulars is essential. A port in the gas-lift mandrel provides communication between the lift-gas supply in the tubing annulus and the production- tubing conduit. Source: IADC UBO / MPD Glossary, December 2011. Global StandardsGas-Tight
Definition(s)
Gas-Tight
Capable of holding gas without leaking under the specified pressure for the specified length of time. Source: API SPEC 7-1, Specification for Rotary Drill Stem Elements, First Edition, March 2006 (Addendum April 2011). Global StandardsGas/Oil Ratio (GOR)
Definition(s)
Gas/Oil Ratio
The volume of gas at atmospheric pressure produced per unit of oil produced. Source: IADC UBO / MPD Glossary, December 2011. Global StandardsGas/Oil Ratio
No flowing and/or gas-lift oil wells shall be permitted to produce with excessive gas/oil ratio, except where special orders are operative. Wells that are gas/lifted with gas from gas wells shall be prorated in the same manner as are hi-ratio naturally flowing oil wells, the G.O.R. being defined for this purpose as the total output gas less the total input gas divided by the number of barrels of oil produced. The uneconomic or unreasonable use of gas for gas-lift will not be permitted. Source: Natural Resources, Office of Conservation – General Operations, Louisiana Administrative Code, Title 43, Part XIX, March 2013. RegulationsGases, Heavier-than-air
Definition(s)
Gases, Heavier-than-air
Gases with a specific gravity greater than 1.0. 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 StandardsGases, lighter-than-air
Definition(s)
Gases, lighter-than-air
Gases with a specific gravity less than 1.0. 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 StandardsGasket
Definition(s)
Gasket
Deformable material (or combination of materials) used to prevent leakage of fluid between two surfaces. Source: API Standard 2RD, Dynamic Risers for Floating Production Systems, Second Edition, September 2013. Global StandardsGasket
Deformable material (or combination of materials) intended to be clamped between flanges to prevent leakage of fluid. Source: API RP 17G, Recommended Practice for Completion/Workover Risers, Second Edition, July 2006 (Reaffirmed April 2011). Global StandardsGasket-Retaining Load
Definition(s)
Gasket-Retaining Load
Portion of the clamping load required to offset the separating force the gasket exerts on the hubs when pressurized. Source: API SPEC 16A, Specification for Drill-through Equipment, Third Edition, June 2004 (Errata/Supplement November 2004). Global StandardsGasket-Retaining Load
That portion of the clamping load required to offset the separating force the gasket exerts on the mating parts when pressurized. Source: API SPEC 16RCD, Specification for Drill Through Equipment—Rotating Control Devices, Upstream Segment, First Edition, February 2005. Global StandardsGasket-Seating Load
Definition(s)
Gasket-Seating Load
That portion of the clamping load required to seat the gasket and bring the hub faces into contact. Source: API SPEC 16A, Specification for Drill-through Equipment, Third Edition, June 2004 (Errata/Supplement November 2004). Global StandardsGasket-Seating Load
That portion of the clamping load required to seat the gasket and bring the mating RCD and RCD bearing assembly faces into contact. Source: API SPEC 16RCD, Specification for Drill Through Equipment—Rotating Control Devices, Upstream Segment, First Edition, February 2005. Global StandardsGassy System
Definition(s)
Gassy System
Gassy systems are those in which the unwanted reaction produces non-condensable products and the rate of temperature rise is not tempered by boiling liquid. Gassy systems can be either liquid-phase decompositions or vapour-phase reactions. Source: API STD 521, Pressure-relieving and Depressuring Systems, Fifth Edition, January 2007 (Addendum May 2008). Global StandardsGastight Door
Definition(s)
Gastight door
“Gastight door” means a solid, close-fitting door designed to resist the passage of gas under normal operating conditions (porte étanche aux gaz). Source: Canada Oil and Gas Installations Regulations, SOR/96-111, Canada, current to May 1, 2014. Regulations Source: Canada Oil and Gas Installations Regulations, SOR/96-118, February 2013. Regulations Source: Nova Scotia Offshore Petroleum Installations Regulations, SOR/95-191, Canada, current to May 31, 2012. RegulationsGas-tight Door
Solid, close fitting door designed to resist the passage of gas under normal atmospheric conditions. Source: IEC 61892-7, Mobile and fixed offshore units – Electrical installations – Part 7: Hazardous areas. Global StandardsGastight door
Gastight door is a solid, close-fitting door designed to resist the passage of gas under normal atmospheric conditions. Source: IMO Resolution A.1023(26), Code for the Construction and Equipment of Mobile Offshore Drilling Units (2009 MODU Code), 2009. Global StandardsGastight Sealed (Secondary) Cell
Definition(s)
Gastight Sealed (secondary) Cell
A secondary cell which remains closed and does not release either gas or liquid when operated within the limits and temperature specified by the manufacturer. The cell may be equipped with a safety device to prevent dangerously high internal pressure. The cell does not require addition to the electrolyte and is designed to operate during its life in its original sealed state. Source: IEC 61892-6, Mobile and fixed offshore units – Electrical installations – Part 6: Installation. Global StandardsGate Search
Definition(s)
Gate Search
The routine inspection of persons and vehicles entering or leaving the facility. Source: API RP 781 Security Plan Methodology for the Oil and Natural Gas Industries.1st Ed. September 2016. Global StandardsGate Valve
Definition(s)
Gate Valve
A valve that employs a sliding gate to open or close the flow passage. NOTE: The valve may or may not be full opening. Source: API STD 53, Blowout Prevention Equipment Systems for Drilling Wells, Upstream Segment, Fourth Edition, November 2012. Global StandardsGate Valve
A valve that employs a sliding gate to open or close the flow passage. Source: API RP 64, Recommended Practice for Diverter Systems Equipment and Operations, Second Edition, November 2001 (March 1, 2007). Global StandardsGate Valve
Valve assembly with a gate operating within the body, 90° to the conduit, to effect a closure. Source: API SPEC 6A, Specification for Wellhead and Christmas Tree Equipment, Twentieth Edition, October 2010 (Addendum November 2012). Global StandardsGate Valve
Valve that closes by lowering a flat plate or gate to block the flow through the valve. Source: IADC UBO / MPD Glossary, December 2011. Global StandardGauge Carrier
Definition(s)
Gauge Carrier
Tool used to convey gauges downhole.
Source:API SPECIFICATION 19TT, Specification for Downhole Well Test Tools and Related Equipment, First Edition, October 2016. Global StandardsGauge OD
Definition(s)
Gauge OD
Maximum specified product OD. Source: API SPEC 11D1, Packers and Bridge Plugs, Upstream Segment, Second Edition, July 2009. Global StandardsGauge Point
Definition(s)
Gauge Point
Plane perpendicular to the thread axis in API rotary shouldered connections. NOTE The gauge point is located 15,9 mm (0.625 in) from the shoulder of the product pin. Source: API SPEC 7-1, Specification for Rotary Drill Stem Elements, First Edition, March 2006 (Addendum April 2011). Global StandardsGauge Pressure
Definition(s)
Gauge Pressure
Measured relative to the ambient pressure (e.g. atmospheric for surface application, hydrostatic for subsea application), measured in “psig”. Source: API Specification 16A, Specification for Drill-through Equipment, Fourth Edition, April 2017. Global StandardsGauge Pressure
Pressure relative to atmospheric pressure. Source: IADC UBO / MPD Glossary, December 2011. Global StandardsGauge, Downhole
Definition(s)
Gauge, Downhole
A device designed to measure downhole parameters such as pressure and/or temperature.
Source:API SPECIFICATION 19TT, Specification for Downhole Well Test Tools and Related Equipment, First Edition, October 2016. Global StandardsGauss
Definition(s)
Gauss (G)
Unit of flux density or induction. Numerically, one gauss is one line of flux per square centimetre of area. Source: API RP 5A5, Field Inspection of New Casing, Tubing, and Plain-end Drill Pipe, Reaffirmed August 2010. Global StandardsGauss Meter
Definition(s)
Gauss Meter
Electronic magnetometer used to measure flux density. Source: API RP 5A5, Field Inspection of New Casing, Tubing, and Plain-end Drill Pipe, Reaffirmed August 2010. Global StandardsGel Coat
Definition(s)
Gel Coat
Quick-setting resin applied either a) to the surface of a mould and gelled before lay-up or b) to the exterior of a laminate as part of the external corrosion barrier.- Note: 1 to entry: The gel coat becomes an integral part of the finished laminate, and is usually used to provide specific service characteristics [see liner (3.2.69)].
General Corrosion
Definition(s)
General Corrosion
Corrosion that is distributed more or less uniformly over the surface of the metal, as opposed to localized corrosion.
Source: API 510, Pressure Vessel Inspection Code: In-service Inspection, Rating, Repair, and Alteration, Tenth Edition, May 2014, with Addendum May 2017. Global StandardsGeneral Corrosion
Corrosion that is distributed more or less uniformly over the surface of the piping, as opposed to being localized in nature.
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 Standards