Glossary
Browse the IADC Lexicon alphabetically or by category. Get comprehensive definitions of drilling industry terms.
Conductor Housing
Definition(s)
Conductor Housing
Top of the first casing string, which forms the basic foundation of the subsea wellhead and provides attachments for guidance structures. 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 StandardsCompletion/Workover Riser
Definition(s)
Completion/Workover Riser
Extension of the production and/or annulus bore(s) of a subsea well to a surface vessel. See ISO 13628-7. 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 StandardsBore Protector
Definition(s)
Bore Protector
Device that protects internal bore surfaces during drilling or workover operations. 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 StandardsBackdriving 〈Stepping-Actuated Choke〉
Definition(s)
Backdriving 〈Stepping-Actuated Choke〉
Condition where the valve changes position after the operator is disengaged. 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 StandardsBackdriving 〈Rotary Actuator〉
Definition(s)
Backdriving 〈Rotary Actuator〉
Condition where the valve continues to change position subsequent to the completion of a positional movement. 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 StandardsBackdriving 〈Manual/ROV Operated Choke〉
Definition(s)
Backdriving 〈Manual/ROV Operated Choke〉
Condition where the valve changes position after the operator is disengaged. 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 StandardsPolar Class ship
Definition(s)
Polar Class ship
Polar Class ship means a ship for which a Polar Class has been assigned. Source: IMO resolution A.1021(26), Guidelines for ships operating in polar waters, 18 January 2010, International Maritime Organization. Regulatory GuidancePolar Class
Definition(s)
Polar Class
Polar Class means the class assigned to a ship based upon IACS Unified Requirements. Source: IMO resolution A.1021(26), Guidelines for ships operating in polar waters, 18 January 2010, International Maritime Organization. Regulatory GuidanceBackdriving 〈Linear Actuator〉
Definition(s)
Backdriving 〈Linear Actuator〉
Condition where the valve drifts from the set position. 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 StandardsBackdriving 〈General〉
Definition(s)
Backdriving 〈General〉
An unplanned movement in the reverse direction of an operation. 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 StandardsAnnulus Seal Assembly
Definition(s)
Annulus Seal Assembly
Mechanism that provides pressure isolation between each casing hanger and the wellhead housing. 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 StandardsRCD
Definition(s)
RCD
Rotating control device. Source: ABS Guide for Classification and Certification of Managed Pressure Drilling Systems, September 2017. Global Standards Source: API Specification 16Q, Design, Selection, Operation, and Maintenance of Marine Drilling Riser Systems, Second Edition, April 2017. Global Standards Source: API SPEC 16RCD, Specification for Drill Through Equipment—Rotating Control Devices, Upstream Segment, First Edition, February 2005. Global Standards Source: Oil & Gas UK, Guidelines on subsea BOP systems, Issue 1, July 2012, Global StandardsRCD
Drill through equipment designed to allow the rotation of the drill string and containment of pressure by the use of seals or packers that seal against the drill string (drill pipe, casing, etc.). Source: ABS Guide for Classification and Certification of Managed Pressure Drilling Systems, September 2017. Global StandardsRCD
Drill-through device with a rotating seal that allows continued drilling operations while maintaining pressure in the wellbore. Source: API Specification 16Q, Design, Selection, Operation, and Maintenance of Marine Drilling Riser Systems, Second Edition, April 2017. Global StandardsPDC
Definition(s)
PDC
Product description code. Source: API SPEC 16RCD, Specification for Drill Through Equipment—Rotating Control Devices, Upstream Segment, First Edition, February 2005. Global StandardsICLL
Definition(s)
ICLL
ICLL means the International Convention on Load Lines, 1966. Source: IMO resolution A.1021(26), Guidelines for ships operating in polar waters, 18 January 2010, International Maritime Organization. Regulatory GuidanceAE
Definition(s)
Ae
Spudcan effective bearing area based on cross-section taken at uppermost part of bearing area in contact with soil.
Source: ABS Guidance Notes on Geotechnical Performance of Spudcan Foundations, January 2017. Global StandardsAE
Acoustic Emissions. Source: API STANDARD 16AR, Standard for Repair and Remanufacture of Drill-through Equipment, First Edition, April 2017. Global Standards Source: API Specification 16A, Specification for Drill-through Equipment, Fourth Edition, April 2017. Global Standards Source: API SPEC 16RCD, Specification for Drill Through Equipment—Rotating Control Devices, Upstream Segment, First Edition, February 2005. Global StandardsWeld, Major Repair
Definition(s)
Weld, Major Repair
Welds that are greater than 25% of the original wall thickness or 1 in., whichever is less. Source: API SPEC 16RCD, Specification for Drill Through Equipment—Rotating Control Devices, Upstream Segment, First Edition, February 2005. Global StandardsWeld, Full Penetration
Definition(s)
Weld, Full Penetration
A weld which extends throughout the complete wall section of the parts joined. Source: API SPEC 16RCD, Specification for Drill Through Equipment—Rotating Control Devices, Upstream Segment, First Edition, February 2005. Global StandardsTrepanned
Definition(s)
Trepanned
To produce a hole through a part by boring a narrow band or groove around the circumference of the hole and removing the solid central core of material. Source: API SPEC 16RCD, Specification for Drill Through Equipment—Rotating Control Devices, Upstream Segment, First Edition, February 2005. Global StandardsSurface Finish
Definition(s)
Surface Finish
Measurement of the average roughness of a surface. Source: API Specification 16A, Specification for Drill-through Equipment, Fourth Edition, April 2017. Global StandardsSurface Finish
The measurement of the average roughness (RMS) of a surface. All of the surface finishes given within this specification are to be considered maximums. Source: API SPEC 16RCD, Specification for Drill Through Equipment—Rotating Control Devices, Upstream Segment, First Edition, February 2005. Global StandardsStructure, Wrought
Definition(s)
Structure, Wrought
One that contains no cast dendritic structure. Source: API SPEC 16RCD, Specification for Drill Through Equipment—Rotating Control Devices, Upstream Segment, First Edition, February 2005. Global StandardsStripping Pressure Rating
Definition(s)
Stripping Pressure Rating
A procedure for running or pulling pipe from the well bore with pressure in the annulus. Source: API SPEC 16RCD, Specification for Drill Through Equipment—Rotating Control Devices, Upstream Segment, First Edition, February 2005. Global StandardsStatic Pressure Rating
Definition(s)
Static Pressure Rating
The maximum pressure that the equipment is designed to control with no pipe movement. Source: API SPEC 16RCD, Specification for Drill Through Equipment—Rotating Control Devices, Upstream Segment, First Edition, February 2005. Global StandardsStabilized (Temperature Testing)
Definition(s)
Stabilized (Temperature Testing)
State in which the initial temperature fluctuations have decreased to within the manufacturer's specified range.- NOTE: Temperature fluctuation can be caused by such things as mixing different-temperature fluids, convection, or conduction.
Stabilized (Temperature Testing)
When the initial temperature fluctuations decrease to within the manufacturer’s specified range. This temperature fluctuation can be caused by such things as mixing of different temperature fluids, convection, or conduction. Source: API SPEC 16RCD, Specification for Drill Through Equipment—Rotating Control Devices, Upstream Segment, First Edition, February 2005. Global StandardsStabilized (Pressure Testing)
Definition(s)
Stabilized (Pressure Testing)
State in which the initial pressure-decline rate has decreased to within the manufacturer's specified rate.- NOTE: Pressure decline can be caused by such things as changes in temperature, setting of elastomer seals, or compression of air trapped in the equipment being tested.
Stabilized (Pressure Testing)
When the initial pressure decline rate decreases to within the manufacturer’s specified rate. This pressure decline can be caused by such things as changes in temperature, setting of elastomer seals or compression of trapped air in the equipment being tested. Source: API SPEC 16RCD, Specification for Drill Through Equipment—Rotating Control Devices, Upstream Segment, First Edition, February 2005. Global StandardsSpecial Processes
Definition(s)
Special Processes
Operations which convert or affect material properties. Source: API SPEC 16RCD, Specification for Drill Through Equipment—Rotating Control Devices, Upstream Segment, First Edition, February 2005. Global StandardsRotating Speed Rating
Definition(s)
Rotating Speed Rating
The maximum rotating speed specified at a given pressure for a specific pipe size as defined by the manufacturer. Source: API SPEC 16RCD, Specification for Drill Through Equipment—Rotating Control Devices, Upstream Segment, First Edition, February 2005. Global StandardsRotating Control Device (RCD)
Definition(s)
Rotating Control Device
Drill through equipment designed to allow the rotation of the drill string and containment of pressure by the use of seals or packers that seal against the drill string (drill pipe, casing, etc.). Source: ABS Guide for Classification and Certification of Managed Pressure Drilling Systems, September 2017. Global StandardsRotating Control Device
Drill-through device with a rotating seal that allows continued drilling operations while maintaining pressure in the wellbore.
Source: API Specification 16Q, Design, Selection, Operation, and Maintenance of Marine Drilling Riser Systems, Second Edition, April 2017. Global Standards