Glossary
Browse the IADC Lexicon alphabetically or by category. Get comprehensive definitions of drilling industry terms.
QT
Definition(s)
QT
Quenched and tempered. 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 StandardsL+T
Definition(s)
L+T
Longitudinal plus transverse. 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 StandardsHF
Definition(s)
HF
Hot-finished. 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 StandardsHF
High frequency. Source: API SPEC 17F, Specification for Subsea Production Control Systems, Second Edition, December 2006 (Reaffirmed April 2011). Global StandardsESR
Definition(s)
ESR
Electro-slag remelting. 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 StandardsCH
Definition(s)
CH
Cold hardened. 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 StandardsAOD
Definition(s)
AOD
Argon oxygen decarburization. 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 StandardsTest Lot Or Lot
Definition(s)
Test Lot Or Lot
Unit formed by products from the same heat, with the same specified outside diameter and wall thickness, the same grade, the same manufacturing process, the same final heat treatment conditions, the same cold hardening parameters if applicable and in the range length as defined in Table A.16 and Table C.16. NOTE The maximum number of products in a test lot is found on Table A.21 and Table C.21. 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 StandardsTempering
Definition(s)
Tempering
Heat treatment requiring heating, one or more times, to a specific temperature below the lower critical temperature and holding at that temperature. NOTE 1 Tempering is often preceded by quench hardening. NOTE 2 Adapted from ISO 4885. 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 StandardsSolution Annealing
Definition(s)
Solution Annealing
Heat treatment requiring heating to a suitable temperature, holding at that temperature long enough to cause one or more constituents to enter into solid solution, then cooling rapidly enough to hold such constituents in solution. 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 StandardsQuench Hardening Or Quenching
Definition(s)
Quench Hardening Or Quenching
Heat treatment requiring austenitization followed by cooling, under conditions such that austenite transforms into martensite. NOTE 1 Quench hardening is often followed by tempering. NOTE 2 Adapted from ISO 4885. 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 StandardsProduct Or Tubular Product
Definition(s)
Product Or Tubular Product
Pipe or coupling stock as applicable. 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 StandardsLinear Imperfection
Definition(s)
Linear Imperfection
Imperfection including, but not limited to, seams, laps, cracks, plug scores, cuts and gouges. 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 StandardsLinear Imperfection
Imperfection which includes, but is not limited to, seams, laps, cracks, plug scores, cuts and gouges. NOTE See API Std 5T1. Source: API SPEC 5CT, Specification for Casing and Tubing, Upstream Segment, Ninth Edition, July 2011 (Errata September 2012). Global StandardsLinear Imperfection
Imperfection that includes, but is not limited to, seams, laps, cracks, plug scores, cuts, gouges and elephant hide. NOTE See API 5T1. [ISO 11960:2004, definition 4.1.25]. Source: API SPEC 5DP, Specification for Drill Pipe, First Edition, August 2009. Global StandardsImperfection
Definition(s)
Imperfection
Discontinuity on the product surface or in the product wall that can be detected by visual inspection or an NDE method outlined in this International Standard. 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 StandardsImperfection
Discontinuity in the product wall or on the product surface that can be detected by a NDE method included in Table C.42 or Table E.42 of this Standard. Source: API SPEC 5CT, Specification for Casing and Tubing, Upstream Segment, Ninth Edition, July 2011 (Errata September 2012). Global StandardsImperfection
Discontinuity in the product wall or on the product surface that can be detected by an NDE method included in this International Standard. [ISO 11960:2004, definition 4.1.16]. Source: API SPEC 5DP, Specification for Drill Pipe, First Edition, August 2009. Global StandardsHot Finished
Definition(s)
Hot Finished
An imperfection, whose type or size, exceeds the applicable acceptance criteria. 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 StandardsCoupling Stock
Definition(s)
Coupling Stock
Seamless thick-wall tubular product used for the manufacture of coupling blanks. 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 StandardsCoupling Stock
Coupling material that meets the coupling stock requirements. Source: API SPEC 5CT, Specification for Casing and Tubing, Upstream Segment, Ninth Edition, July 2011 (Errata September 2012). Global StandardsCorrosion-Resistant Alloy (CRA)
Definition(s)
Corrosion-Resistant Alloy (CRA)
Alloy intended to be resistant to general and localized corrosion and/or environmental cracking in environments that are corrosive to carbon and low-alloy steels. 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 StandardsCorrosion-Resistant Alloy (CRA)
Nonferrous-based alloy in which any one or the sum of the specified amount of the elements titanium, nickel, cobalt, chromium, and molybdenum exceeds 50 % mass fraction. NOTE This definition is different from that in ISO 15156 (NACE MR0175; see Clause 2). Source: API SPEC 6A, Specification for Wellhead and Christmas Tree Equipment, Twentieth Edition, October 2010 (Addendum November 2012). Global StandardsCorrosion-Resistant Alloy (CRA)
Non-ferrous alloy for which any one or the sum of the specified amount of the following alloy elements exceeds 50 %: titanium, nickel, cobalt, chromium and molybdenum. NOTE This term refers to corrosion-resistant alloys and not cracking-resistant alloys as mentioned in ISO 15156 (all parts). Source: API SPEC 17D, Design and Operation of Subsea Production Systems—Subsea Wellhead and Tree Equipment, Upstream Segment, Second Edition May 2011 (Errata September 2011). Global StandardsCold Hardened
Definition(s)
Cold Hardened
Material condition where the mechanical properties are obtained by a cold finishing process not followed by heat treatment. NOTE 1 Cold finishing is a plastic deformation of material at a temperature below the recrystallization temperature such that permanent strain hardening occurs. NOTE 2 The percentage of cold hardening depends on the specified strength level for each material grade, as shown in Table A.3 or Table C.3 for the cold hardened condition. 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 StandardsCast or Heat
Definition(s)
Cast or Heat
Material of the same category melted in the same manufacturing process at the same time sequence poured into multiple ingots or continuous strand cast. 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 StandardsWell Barrier
Definition(s)
Well Barriers
System of one or several well barrier elements that contain fluids within a well to prevent uncontrolled flow of fluids within or out of the well.Source: ISO 16530-1:2017, Petroleum and natural gas industries — Well integrity – Part 1: Life cycle governance, First Edition, March 2017. Global Standards
Well Barriers
An envelope of one or more well barrier elements that prevents fluids from flowing unintentionally from the formation or well into another formation or to the surface.
Source:API SPECIFICATION 19TT, Specification for Downhole Well Test Tools and Related Equipment, First Edition, October 2016. Global StandardsWell Barrier
Envelope of one or several dependent barrier elements preventing fluids or gases from flowing unintentionally from the formation into another formation or to the surface. Source: API RP 90, Annular Casing Pressure Management for Offshore Wells, Upstream Segment. First Edition, August 2006. Global StandardsThermal Casing Pressure
Definition(s)
Thermal Casing Pressure
Pressure generated within a sealed annulus by thermal expansion of trapped wellbore fluids during production. Source: API RP 90, Annular Casing Pressure Management for Offshore Wells, Upstream Segment. First Edition, August 2006. Global StandardsSustained Casing Pressure (SCP)
Definition(s)
Sustained Casing Pressure (SCP)
Pressure in an annulus of non-structural casing strings that is: 1. measurable at the wellhead of a casing annulus that rebuilds to at least the same pressure level when bled down; 2. not caused solely by temperature fluctuations; and 3. not a pressure that has been imposed by the operator. Source: API RP 90, Annular Casing Pressure Management for Offshore Wells, Upstream Segment. First Edition, August 2006. Global StandardsSurface Well
Definition(s)
Surface Well
A well completed on the surface with individual casing heads, tubing head, a surface tubing hanger, and a surface christmas tree, all residing at a designated level above the water line on a fixed platform. Source: API RP 90, Annular Casing Pressure Management for Offshore Wells, Upstream Segment. First Edition, August 2006. Global StandardsSecondary Well Barrier
Definition(s)
Secondary Well Barrier
Second set of well barrier elements that prevent flow from a source of inflow. [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 StandardsSecondary Well Barrier
Second set of barrier elements that prevents flow from a source. Source: API RP 90, Annular Casing Pressure Management for Offshore Wells, Upstream Segment. First Edition, August 2006. Global StandardsPrimary Well Barrier
Definition(s)
Primary Well Barrier
First set of well barrier elements that prevent flow from a source of inflow. Source: ISO 16530-1:2017, Petroleum and natural gas industries — Well integrity – Part 1: Life cycle governance, First Edition, March 2017. Global StandardsPrimary Well Barrier
First set of barrier elements that prevents flow from a source. Source: API RP 90, Annular Casing Pressure Management for Offshore Wells, Upstream Segment. First Edition, August 2006. Global StandardsLiner Casing
Definition(s)
Liner Casing
A casing string suspended near the bottom end of a previous casing string using a liner hanger. Source: API RP 90, Annular Casing Pressure Management for Offshore Wells, Upstream Segment. First Edition, August 2006. Global StandardsCombination Casing String
Definition(s)
Combination Casing String
A casing string consisting of more than one type of casing is called a combination casing string. A casing string that includes a separate smaller casing string suspended from the base of the previous string (liners) will also be classified as combination casing strings. Source: API RP 90, Annular Casing Pressure Management for Offshore Wells, Upstream Segment. First Edition, August 2006. Global StandardsBarrier Elements
Definition(s)
Barrier Elements
One or several dependent objects, i.e., packers, tubing, or casing, preventing formation fluids from flowing unintentionally into another formation or to the surface. Source: API RP 90, Annular Casing Pressure Management for Offshore Wells, Upstream Segment. First Edition, August 2006. Global StandardsB-Annulus
Definition(s)
B-Annulus
Designation of an annulus between the production casing and the next outer casing- Note 1 to entry: The letter designation continues in sequence for each outer annulus space encountered between casing strings, up to and including the surface casing and conductor casing strings.