Global Standards

Definition(s)

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Gimbal

Device that interfaces with the spider and the riser joint and enables the riser to rotate about the horizontal axis, thereby reducing the bending moments, which can otherwise occur due to vessel roll/pitch motions. Source: API RP 17G, Recommended Practice for Completion/Workover Risers, Second Edition, July 2006 (Reaffirmed April 2011). Global Standards  

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Glass Transition Temperature

Temperature at which the amorphous portion of the polymer undergoes a marked change in properties on passing from the rubbery to glassy state.

• Note: 1 to entry: This observed change in properties is associated with the virtual cessation of local molecular motion in the polymer. Below their glass-transition temperature, amorphous polymers have many of the properties associated with ordinary inorganic glasses, while above this temperature the polymers possess rubbery characteristics.

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 Standards

Glass Transition Temperature

The temperature below which elastomers exhibit brittle, glass-like behavior.

Source:API SPECIFICATION 7K, Drilling and Well Servicing Equipment, Sixth Edition, December 2015. Global Standards

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Glass-fibre-reinforced epoxy

Epoxy resin-based composite that is reinforced with glass fibre. 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 Standards

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Glass-fibre-reinforced plastic

Composite material made of thermosetting resin and reinforced with glass fibres. Source: ISO 21457:2010, Petroleum and natural gas industries — Materials selection and corrosion control for oil and gas production systems, First Edition,September 2010. Global Standards

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Glass-fibre-reinforced unsaturated polyster

Unsaturated polyester resin-based composite that is reinforced with glass fibre. 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 Standards

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Glass-fibre-reinforced vinyl ester

Epoxy vinyl ester resin-based composite that is reinforced with glass fibre. 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 Standards

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Global Analysis

Analysis of the complete riser string from the sea floor (wellhead) to top including tensioner joint. NOTE Bending moments and effective tension distributions along the riser string due to functional loads, vessel motions and environmental loads are determined by global analysis. Source: API Standard 2RD, Dynamic Risers for Floating Production Systems, Second Edition, September 2013. Global Standards  

Global Analysis

Analysis of the complete riser string from the sea floor (wellhead) to top drive including tensioner joint, utilizing beam element. NOTE Bending moments and effective tension distributions along the riser string due to functional loads, vessel motions and environmental loads are determined by global analysis. Source: API RP 17G, Recommended Practice for Completion/Workover Risers, Second Edition, July 2006 (Reaffirmed April 2011). Global Standards  

Global Analysis

Determination of a consistent set of internal forces and moments, or stresses, in a structure that are in equilibrium with a defined set of actions on the entire structure. NOTE 1 When a global analysis is of a transient situation (e.g. earthquake), the inertial response is part of the equilibrium. NOTE 2 Adapted from ISO 19902:2007, definition 3.23. Source: ISO 19905-1:202, Petroleum and natural gas industries – Site-specific assessment of mobile offshore units – Part 1: Jack-ups. Global Standards

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Global Buckling

Elastic Euler buckling. Source: API RP 17G, Recommended Practice for Completion/Workover Risers, Second Edition, July 2006 (Reaffirmed April 2011). Global Standards  

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Globe Valve

Valve that opens or closes when a plug attached to the stem moves linearly in the spherical valve body. Source: IADC UBO / MPD Glossary, December 2011. Global Standards

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Glued 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.

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 Standards

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GLV

Gas Lift Valve. Source: 117 OLF, Norwegian Oil and Gas Association recommended guidelines for Well Integrity, No. 117, Revision No. 4, June 2011. Global Standards  

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Glycol

Dihydric alcohol where different carbon atoms bond to the two-hydroxyl groups. The general formula for a glycol is (CH2)n(OH)2. Source: IADC UBO / MPD Glossary, December 2011. Global Standards

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GND

Ground. Source: API SPEC 17F, Specification for Subsea Production Control Systems, Second Edition, December 2006 (Reaffirmed April 2011). Global Standards  

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Gooseneck

Type of terminal fitting designed to achieve a nominal 180° change in flow direction.

Source: API Specification 16Q, Design, Selection, Operation, and Maintenance of Marine Drilling Riser Systems, Second Edition, April 2017. Global Standards

Gooseneck

A type of terminal fitting using a pipe section with a semicircular bend to achieve a nominal 180" change in flow direction. 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 Standards 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

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GOR

Gas-oil ratio. Source: API RP 17A, Design and Operation of Subsea Production Systems—General Requirements and Recommendations, Fourth Edition, Reaffirmed 2011. Global Standards 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

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Gouge

Elongated grooves or cavities caused by mechanical removal of metal. Source: API RP 7G-2, Recommended Practice for Inspection and Classification of Used Drill Stem Elements, First Edition, August 2009. Global Standards  

Gouge

Elongated groove or cavity caused by mechanical removal of metal. Source: API SPEC 5DP, Specification for Drill Pipe, First Edition, August 2009. Global Standards  

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Governance of Information Security

System by which an organization’s information security activities are directed and controlled. Source: ISO/IEC 27000:2014, Information technology — Security techniques — Information security management systems — Overview and vocabulary, Third Edition, January 2014. Global Standards

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Governing Body

Person or group of people who are accountable for the performance and conformance of the organization.

• Note 1 to entry: Governing body can in some jurisdictions be a board of directors.

Source: ISO/IEC 27000:2014, Information technology — Security techniques — Information security management systems — Overview and vocabulary, Third Edition, January 2014. Global Standards

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GPO

Group policy object. Source:  DNVGL-RP-G108, Cyber security in the oil and gas industry based on IEC 62443, DNV GL, September 2017. Global Standards

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Grade

Category or rank given to different requirements for quality or design validation. Source: API SPEC 11D1, Packers and Bridge Plugs, Upstream Segment, Second Edition, July 2009. Global Standards

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Grades of Release

There are three basic grades of release, as listed below in order of decreasing frequency and likelihood of the explosive gas atmosphere being present: a) continuous grade; b) primary grade; c) secondary grade. A source of release may give rise to any one of these grades of release, or to a combination of more than one. Source: IEC 61892-7, Mobile and fixed offshore units – Electrical installations – Part 7: Hazardous areas. Global Standards  

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Gradient

Slope of internal pressure over time, on a logarithmic-logarithmic scale, of a static regression curve.

• Note: 1 to entry: The slope, although negative, is published and used as a positive number.

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 Standards

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Graph

Visual method of showing the relationship between two or more characteristics. Source: IADC UBO / MPD Glossary, December 2011. Global Standards

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Graphical User Interface (GUI)

Computer program user interface using graphics to control the software. Source: IADC UBO / MPD Glossary, December 2011. Global Standards

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Gravitational Energy

Potential energy caused by changes in elevation. Source: IADC UBO / MPD Glossary, December 2011. Global Standards

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Gravitometer

Device to measures the specific gravity of a fluid. Source: IADC UBO / MPD Glossary, December 2011. Global Standards

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Gravity Loads

Gravity and functional loads are loads which exist due to the unit’s weight, use and treatment in still water conditions for each design case. All external forces which are responses to functional loads are to be regarded as functional loads, e.g., support reactions and still water buoyancy forces. Source: Rules and Regulations for the Classification of Mobile Offshore Units, Part 4, Steel Unit Structures, June 2013, Lloyd’s Register, Global Standards