Glossary
Browse the IADC Lexicon alphabetically or by category. Get comprehensive definitions of drilling industry terms.
Imperfection
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 StandardsSeafarer
Definition(s)
Seafarer
Seafarer means any person who is employed or engaged in any capacity on board a seagoing ship. Source: IMO Resolution A.930(22), Guidelines on Provision of Financial Security in Case of Abandonment of Seafarers, 17 December 2001, International Maritime Organization. Regulatory Guidance Source: IMO Resolution A.931(22), Guidelines on Shipowners' Responsibilities in respect of Contractual Claims for Personal Injury to or Death of Seafarers, 17 December 2001, International Maritime Organization. Regulatory GuidanceSeafarer
A seafarer means any person who is employed or engaged or works in any capacity on board a ship. Source: IMO Resolution MSC.255(84), Code of the International Standards and Recommended Practices for a Safety Investigation into a Marine Casualty or Marine Incident (Casualty Investigation Code), 16 May 2008, International Maritime Organization. Regulatory GuidanceCast 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 StandardsStructural Pipe Casing Strings
Definition(s)
Structural Pipe Casing Strings
Casing strings used to facilitate the drilling of the well, but not needed for pressure containment after the well has been drilled. Support unconsolidated sediments and provide hole stability for initial drilling operations, axial support for casing loads and bending loads from the subsea wellhead. Source: API RP 90, Annular Casing Pressure Management for Offshore Wells, Upstream Segment. First Edition, August 2006. Global StandardsSection Of A Casing String
Definition(s)
Section Of A Casing String
A section of a casing string is defined as a continuous length of casing. 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 StandardsProduction Tubing
Definition(s)
Production Tubing
Tubing that is run inside the production casing and used to convey produced fluids from the hydrocarbon-bearing formation to the surface. Tubing may also be used for injection. In hybrid wells, for example, tubing is used as a conduit for gas for artificial lift below a mudline pack-off tubing hanger to isolate the gas lift pressure from the production riser. Source: API RP 90, Annular Casing Pressure Management for Offshore Wells, Upstream Segment. First Edition, August 2006. Global StandardsProduction String (or Completion String)
Definition(s)
Production String (or Completion String)
The production string consists primarily of production tubing, but also includes additional components such as the surface-controlled subsurface safety valve (SCSSV), gas lift mandrels, chemical injection and instrument ports, landing nipples, and packer or packer seal assemblies. The production string is run inside the production casing and used to conduct production fluids to the surface. 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.
B-Annulus
The annulus designation between the production casing and next outer casing. The letter designation continues in sequence for each and every outer annular space encountered between casing strings up to and including the surface casing and conductor casing strings. Source: API RP 90, Annular Casing Pressure Management for Offshore Wells, Upstream Segment. First Edition, August 2006. Global StandardsB-Annulus
Annuli between the production casing and the previous casing string. Source: NORSOK D-010, Well integrity in drilling and well operations, Rev. 3, August 2004. Global StandardsThreshold Characteristics/Operating Conditions
Definition(s)
Threshold Characteristics/Operating Conditions
Criteria established by relevant governmental agencies or the facility owner/operator for screening critical offshore facilities. This is the primary Facility evaluation. Source: API RP 70I, Security for Worldwide Offshore Oil and Natural Gas Operations, Upstream Segment, First Edition, May 2004. Global StandardsWing-In-Ground (WIG)
Definition(s)
Wing-In-Ground (WIG)
The term “Wing-In-Ground (WIG) craft” means a multimodal craft which, in its main operational mode, flies in close proximity to the surface by utilizing surface-effect action. Source: IMO Resolution A.910(22), Amendments to the Convention on the International Regulations for Preventing Collisions at Sea, 1972, 22 January 2002, International Maritime Organization. LegislationThreshold Characteristics
Definition(s)
Threshold Characteristics
Criteria established and published by the U.S. Coast Guard for screening offshore facilities. Source: API RP 70, Security for Offshore Oil and Natural Gas Operations, Downstream Segment, First Edition, March 2003. Global StandardsSecurity Vulnerability Assessment (SVA)
Definition(s)
Security Vulnerability Assessment (SVA)
A secondary evaluation that examines a facility’s characteristics and operations to identify potential threats or vulnerabilities and existing and prospective security measures and procedures designed to protect a facility. Source: API RP 70, Security for Offshore Oil and Natural Gas Operations, Downstream Segment, First Edition, March 2003. Global Standards Source: API RP 70I, Security for Worldwide Offshore Oil and Natural Gas Operations, Upstream Segment, First Edition, May 2004. Global StandardsPoint Of Embarkation
Definition(s)
Point Of Embarkation
The heliport or dock facility from which personnel and materials are shipped to or received from the offshore facility. Source: API RP 70, Security for Offshore Oil and Natural Gas Operations, Downstream Segment, First Edition, March 2003. Global StandardsPoint Of Embarkation
The heliport or dock facility from which personnel and materials are shipped to or received from the offshore facility. Appropriate security measures at these facilities are critical. Source: API RP 70I, Security for Worldwide Offshore Oil and Natural Gas Operations, Upstream Segment, First Edition, May 2004. Global StandardsFacility Security Officer (FSO)
Definition(s)
Facility Security Officer (FSO)
The person designated as responsible for the development, implementation, revision and maintenance of the facility security plan.
Source: API RP 781 Security Plan Methodology for the Oil and Natural Gas Industries.1st Ed. September 2016. Global Standards