Glossary
Browse the IADC Lexicon alphabetically or by category. Get comprehensive definitions of drilling industry terms.
Hybrid System
Definition(s)
Hybrid System
Hybrid systems are those in which the rate of temperature rise due to an unwanted reaction can be tempered by liquid boiling at system pressure, but can also give rise to the generation of non-condensable gas. Source: API STD 521, Pressure-relieving and Depressuring Systems, Fifth Edition, January 2007 (Addendum May 2008). Global StandardsPup Joint
Definition(s)
Pup Joint
Riser joint that is shorter than standard length.
Source: API Specification 16Q, Design, Selection, Operation, and Maintenance of Marine Drilling Riser Systems, Second Edition, April 2017. Global StandardsPup Joint
Short tubular element used to join two threaded connections.
Source:API SPECIFICATION 19TT, Specification for Downhole Well Test Tools and Related Equipment, First Edition, October 2016. Global StandardsPup Joint
Joint of pipe or tubing shorter than standard length. Source: API Standard 2RD, Dynamic Risers for Floating Production Systems, Second Edition, September 2013. Global StandardsPup Joint
Short pipe length usually with threaded ends. Source: API RP 5C5, Recommended Practice on Procedures for Testing Casing and Tubing Connections, Third Edition, July 2003 (Reaffirmed August 2010). Global StandardsPup Joint
A shorter than standard length riser joint. 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 StandardsPup Joint
Joint of pipe or tubing shorter than standard length. Source: API RP 17G, Recommended Practice for Completion/Workover Risers, Second Edition, July 2006 (Reaffirmed April 2011). Global StandardsPup Joint
Casing or tubing shorter than range 1. Source: API SPEC 5CRA, Specification for Corrosion Resistant Alloy Seamless Tubes for Use as Casing, Tubing and Coupling Stock, Upstream Segment, First Edition, February 2010 (Errata August 2011). Global StandardsPup Joint
Casing or tubing of length shorter than Range 1, see Table C.27 or Table E.27. Source: API SPEC 5CT, Specification for Casing and Tubing, Upstream Segment, Ninth Edition, July 2011 (Errata September 2012). Global StandardsPup Joint
Shorter than standard length riser joint. 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 StandardsPipe String
Definition(s)
Pipe String
Pipe body and the connection. Source: API RP 5C5, Recommended Practice on Procedures for Testing Casing and Tubing Connections, Third Edition, July 2003 (Reaffirmed August 2010). Global StandardsMultiple Seals
Definition(s)
Multiple Seals
Sealing system, which consists of more than one independent barrier, and of which each barrier forms a seal itself. Source: API RP 5C5, Recommended Practice on Procedures for Testing Casing and Tubing Connections, Third Edition, July 2003 (Reaffirmed August 2010). Global StandardsMother Joint
Definition(s)
Mother Joint
Length of pipe or coupling stock from which short lengths are cut for machining connection test specimens. Source: API RP 5C5, Recommended Practice on Procedures for Testing Casing and Tubing Connections, Third Edition, July 2003 (Reaffirmed August 2010). Global StandardsMetal-to-Metal Seal
Definition(s)
Metal-to-Metal Seal
Seal or sealing system that relies on intimate and usually high contact stress of mating metal surfaces to achieve a seal. NOTE The thread compound can affect, both beneficially and detrimentally, the performance of a metal seal. Source: API RP 5C5, Recommended Practice on Procedures for Testing Casing and Tubing Connections, Third Edition, July 2003 (Reaffirmed August 2010). Global StandardsLot
Definition(s)
LOT
Application of pressure by superimposing a surface pressure on a fluid column in order to determine the pressure at which the exposed formation accepts whole fluid [SOURCE: API RP 59, modified]. Source: ISO 16530-1:2017, Petroleum and natural gas industries — Well integrity – Part 1: Life cycle governance, First Edition, March 2017. Global StandardsLot
Lengths of pipe with the same specified dimensions and grade from the same heat of steel which are heat-treated as part of a continuous operation (or batch). Source: API RP 5C5, Recommended Practice on Procedures for Testing Casing and Tubing Connections, Third Edition, July 2003 (Reaffirmed August 2010). Global StandardsLOT
Leak-off test. Source: ISO 16530-1:2017, Petroleum and natural gas industries — Well integrity – Part 1: Life cycle governance, First Edition, March 2017. Global Standards Source: API Bulletin 97, Well Construction Interface Document Guidelines, First Edition, December 2013. Global Standards Source: API RP 96, Deepwater Well Design and Construction, First Edition, March 2013. Global Standards Source: Deepwater Well Control Guidelines. IADC GuidelinesLot
Definite quantity of product manufactured under conditions that are considered uniform for the attribute being inspected. Source: API SPEC 5DP, Specification for Drill Pipe, First Edition, August 2009. Global StandardsLot
Pieces of steel, with the same nominal dimensions and from a single heat, which are subsequently heattreated as part of the same continuous operation (or batch). Source: API SPEC 7-1, Specification for Rotary Drill Stem Elements, First Edition, March 2006 (Addendum April 2011). Global StandardsLot
One lot is defined as all material from the same heat processed at one time. Source: API SPEC 7-1, Specification for Rotary Drill Stem Elements, First Edition, March 2006 (Addendum April 2011). Global StandardsLimit Load
Definition(s)
Limit Load
Load combination extreme (axial load and/or pressure) which defines the failure conditions for the connection or maximum load resulting in large permanent deformation (such as buckling) prior to catastrophic failure. Source: API RP 5C5, Recommended Practice on Procedures for Testing Casing and Tubing Connections, Third Edition, July 2003 (Reaffirmed August 2010). Global StandardsLeak
Definition(s)
Leak
Unintended and undesired movement of fluids. Source: ISO 16530-1:2017, Petroleum and natural gas industries — Well integrity – Part 1: Life cycle governance, First Edition, March 2017. Global StandardsLeak
Any positive displacement of fluid in the measuring system during hold periods. Source: API RP 5C5, Recommended Practice on Procedures for Testing Casing and Tubing Connections, Third Edition, July 2003 (Reaffirmed August 2010). Global StandardsSevere Galling
Definition(s)
Severe Galling
Galling that cannot be repaired by the use of fine files and abrasive paper. Source: API RP 5C5, Recommended Practice on Procedures for Testing Casing and Tubing Connections, Third Edition, July 2003 (Reaffirmed August 2010). Global StandardsModerate Galling
Definition(s)
Moderate Galling
Galling that can be repaired by the use of fine files and abrasive paper. Source: API RP 5C5, Recommended Practice on Procedures for Testing Casing and Tubing Connections, Third Edition, July 2003 (Reaffirmed August 2010). Global StandardsLight Galling
Definition(s)
Light Galling
Galling that can be repaired by the use of abrasive paper. Source: API RP 5C5, Recommended Practice on Procedures for Testing Casing and Tubing Connections, Third Edition, July 2003 (Reaffirmed August 2010). Global StandardsFailure Load
Definition(s)
Failure Load
Load at which the pipe body or connection will fail catastrophically as in an axial separation, a rupture, large permanent deformation (e.g. buckling or collapse) or massive loss of sealing integrity. Source: API RP 5C5, Recommended Practice on Procedures for Testing Casing and Tubing Connections, Third Edition, July 2003 (Reaffirmed August 2010). Global StandardsConnection
Definition(s)
Connection
Assembly consisting of either two pins and a coupling or one pin and an integral box. Source: API RP 5C5, Recommended Practice on Procedures for Testing Casing and Tubing Connections, Third Edition, July 2003 (Reaffirmed August 2010). Global StandardsConnection
Threaded assembly of tubular components. Source: API SPEC 5CT, Specification for Casing and Tubing, Upstream Segment, Ninth Edition, July 2011 (Errata September 2012). Global StandardsAxial-Pressure Load Diagram
Definition(s)
Axial-Pressure Load Diagram
Plot of pressure versus axial load showing pipe and/or connection test load envelope or limit load extremes. Source: API RP 5C5, Recommended Practice on Procedures for Testing Casing and Tubing Connections, Third Edition, July 2003 (Reaffirmed August 2010). 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 StandardsAmbient Temperature
Definition(s)
Ambient Temperature
Prevailing temperature at test site.
Source:API SPECIFICATION 19TT, Specification for Downhole Well Test Tools and Related Equipment, First Edition, October 2016. Global StandardsAmbient Temperature
Actual room temperature in the test lab with no residual heat remaining in test specimens from previous thermal tests. Source: API RP 5C5, Recommended Practice on Procedures for Testing Casing and Tubing Connections, Third Edition, July 2003 (Reaffirmed August 2010). Global StandardsAmbient Temperature
Temperature of the surroundings.. Source: IADC UBO / MPD Glossary, December 2011. Global StandardsTempered System
Definition(s)
Tempered System
Tempered systems are those in which the unwanted reaction produces condensable products and the rate of temperature rise is tempered by liquid boiling at system pressure. Typically, tempered systems are liquid-phase reactions in which a reactant (or solvent) is a major portion of the reactor contents. Source: API STD 521, Pressure-relieving and Depressuring Systems, Fifth Edition, January 2007 (Addendum May 2008). Global StandardsUtility Tip or Pipe-Flare Tip
Definition(s)
Utility Tip or Pipe-Flare Tip
The simplest flare-tip design is commonly referred to as a utility or pipe-flare tip and can consist of little more than a piece of pipe fitted with a flame retention device for flame stability at higher exit velocities (the upper portion is typically stainless steel to endure the high flame temperatures) and a pilot for gas ignition. Source: API STD 521, Pressure-relieving and Depressuring Systems, Fifth Edition, January 2007 (Addendum May 2008). Global StandardsVolumetric Heating
Definition(s)
Volumetric Heating
On the other hand, reactive systems in which an external fire can result in an exothermic reaction are subject to boiling throughout the volume of the vessel due to heat evolved from the reaction. This is commonly referred to as volumetric heating, which results in more liquid-swell than wall-heating and, thus, increases the potential for longer-duration two-phase relief. Source: API STD 521, Pressure-relieving and Depressuring Systems, Fifth Edition, January 2007 (Addendum May 2008). Global StandardsWall-Heating
Definition(s)
Wall-Heating
In non-reactive systems subjected to an external fire, boiling occurs at or near the walls of the vessel, commonly referred to as wall-heating. Source: API STD 521, Pressure-relieving and Depressuring Systems, Fifth Edition, January 2007 (Addendum May 2008). Global StandardsBase of a Pool Fire
Definition(s)
Base of a Pool Fire
The term “base of a pool fire” usually refers to ground level but could be at any level at which a substantial spill or pool fire could be sustained. Various classes of vessels are operated only partially full. Table 5 gives recommended portions of liquid inventory for use in calculations. Wetted surfaces higher than 7,6 m (25 ft) are normally excluded because pool fire flames are not likely to impinge for long durations above this height. Also, vessel heads protected by support skirts with limited ventilation are normally not included when determining wetted area. The user shall specify whether to include the wetted surface area of connected piping in the wetted area calculation. Source: API STD 521, Pressure-relieving and Depressuring Systems, Fifth Edition, January 2007 (Addendum May 2008). Global StandardsSafety Instrumented System
Definition(s)
Safety Instrumented System
System composed of sensors, logic solvers, and final control elements for the purpose of taking the process to a safe state when predetermined conditions are met.- NOTE Other terms commonly used for a SIS include emergency shutdown system (ESD, ESS), safety shutdown system (SSD), and safety interlock system (see E.3.3.1).
Safety Instrumented System
ISA S84.01 defines a safety instrumented system as a “system composed of sensors, logic solvers, and final control elements for the purpose of taking the process to a safe state when predetermined conditions are violated. Other terms commonly used include emergency shutdown system (ESD, ESS), safety shutdown system (SSD), and safety interlock system.” HIPS also fit the definition of a safety instrumented system. Source: API STD 521, Pressure-relieving and Depressuring Systems, Fifth Edition, January 2007 (Addendum May 2008). Global StandardsSafety Instrumented System
System used to implement one or more safety-instrumented functions [2].- Note: A safety-instrumented system is composed of any combination of sensor(s), logic solver(s), and actuator(s).
Windshield
Definition(s)
Windshield
Device used to protect the downwind side of an elevated flare burner from direct flame impingement.- NOTE: Windshields are also integral to the design of pilots to avoid flame-outs due to high winds.
Windshield
Device used to protect the outside of a flare burner from direct flame impingement.- NOTE: The windshield is so named because external flame impingement occurs on the downwind side of an elevated flare burner.
Vent Stack
Definition(s)
Vent Stack
Elevated vertical termination of a disposal system that discharges vapours into the atmosphere without combustion or conversion of the relieved fluid. 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 StandardsVent Header
Definition(s)
Vent Header
Piping system that collects and delivers the relief gases to the vent stack. 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 StandardsVelocity Seal
Definition(s)
Velocity Seal
Dry vapor seal based on a flow restriction that minimizes the required purge gas needed to protect against air infiltration into the flare burner exit.
Source: API STD 521, Pressure-relieving and Depressuring Systems, Sixth Edition, January 2014. Global Standards