Glossary
Browse the IADC Lexicon alphabetically or by category. Get comprehensive definitions of drilling industry terms.
Precision
Definition(s)
Precision
In this part of ISO 10426, calibrating an instrument refers to assuring the accuracy of the measurement. Accuracy is the degree of conformity of a measurement of a quantity to its actual or true value. Accuracy is related to precision, or reproducibility, of a measurement. Precision is the degree to which further measurements or calculations will show the same or similar results. Precision is characterized in terms of the standard deviation of the measurement. The results of calculations or a measurement can be accurate, but not precise, precise but not accurate, neither or both. A result is valid if it is both accurate and precise. Source: API SPEC 10A, Specification for Cements and Materials for Well Cementing, Twenty-fourth Edition, December 2010. Global StandardsAccuracy
Definition(s)
Accuracy
In this part of ISO 10426, calibrating an instrument refers to assuring the accuracy of the measurement. Accuracy is the degree of conformity of a measurement of a quantity to its actual or true value. Accuracy is related to precision, or reproducibility, of a measurement. Precision is the degree to which further measurements or calculations will show the same or similar results. Precision is characterized in terms of the standard deviation of the measurement. The results of calculations or a measurement can be accurate, but not precise, precise but not accurate, neither or both. A result is valid if it is both accurate and precise. Source: API SPEC 10A, Specification for Cements and Materials for Well Cementing, Twenty-fourth Edition, December 2010. Global StandardsCalibrating
Definition(s)
Calibrating
In this part of ISO 10426, calibrating an instrument refers to assuring the accuracy of the measurement. Accuracy is the degree of conformity of a measurement of a quantity to its actual or true value. Accuracy is related to precision, or reproducibility, of a measurement. Precision is the degree to which further measurements or calculations will show the same or similar results. Precision is characterized in terms of the standard deviation of the measurement. The results of calculations or a measurement can be accurate, but not precise, precise but not accurate, neither or both. A result is valid if it is both accurate and precise. Source: API SPEC 10A, Specification for Cements and Materials for Well Cementing, Twenty-fourth Edition, December 2010. Global StandardsSlurry Container or Slurry Cup
Definition(s)
Slurry Container or Slurry Cup
Container in an atmospheric or pressurized consistometer used to hold the slurry for conditioning purposes or for the thickening-time test. Source: API SPEC 10A, Specification for Cements and Materials for Well Cementing, Twenty-fourth Edition, December 2010. Global StandardsCement Class
Definition(s)
Cement Class
Designation achieved under the ISO system for classification of well cement according to its intended use. Source: API SPEC 10A, Specification for Cements and Materials for Well Cementing, Twenty-fourth Edition, December 2010. Global StandardsCement Or Portland Cement
Definition(s)
Cement Or Portland Cement
Ground clinker generally consisting of hydraulic calcium silicates and aluminates and usually containing one or more forms of calcium sulfate as an interground additive. Source: API SPEC 10A, Specification for Cements and Materials for Well Cementing, Twenty-fourth Edition, December 2010. Global StandardsBearden Unit of Consistency (Bc)
Definition(s)
Bearden Unit of Consistency (Bc)
Measure of the consistency of a cement slurry when determined on a pressurized consistometer. Source: API SPEC 10A, Specification for Cements and Materials for Well Cementing, Twenty-fourth Edition, December 2010. Global StandardsBearden Units of Consistency
Units used to express consistency of a cement slurry when determined on a pressurized consistometer. NOTE The symbol for consistency when expressed in Bearden units is Bc. Source: API RP 10B-2, Recommended Practice for Testing Well Cements, First Edition, July 2005 (Reaffirmed: July 2010). Global StandardsAtmospheric Pressure Consistometer
Definition(s)
Atmospheric Pressure Consistometer
Device used for stirring and conditioning the cement slurry. NOTE The device is not intended to measure thickening time. Source: API SPEC 10A, Specification for Cements and Materials for Well Cementing, Twenty-fourth Edition, December 2010. Global StandardsPLC
Definition(s)
PLC
Principal loading condition. Source: API SPEC 8C, Drilling and Production Hoisting Equipment (PSL 1 and PSL 2), Fifth Edition, April 2012. Global StandardsPLC
Programmable logic controller. Source: IADC UBO / MPD Glossary, December 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 Source: NORSOK D-001, Drilling facilities, Rev. 3, December 2012. Global Standards Source: Oil & Gas UK, Guidelines on subsea BOP systems, Issue 1, July 2012, Global Standards Source: ANSI/ISA–99.00.01–2007, Security for Industrial Automation and Control Systems, Part 1: Terminology, Concepts, and Models, 29 October 2007. National StandardProduct Specification Level
Definition(s)
Product Specification Level
Categories of design requirements based on the application.
Source: API Standard 2CCU, Offshore Cargo Carrying Units, First Edition, August 2017. Global StandardsProduct Specification Level
Degree of controls applied on materials and processes for the primary load-carrying components of the equipment.- NOTE: The two product specification levels are identified by the code PSL 1 or PSL 2.
Load Rating
Definition(s)
Load Rating
Maximum operating load, both static and dynamic, to be applied to the equipment. NOTE The load rating is numerically equivalent to the design load. Source: API SPEC 8C, Drilling and Production Hoisting Equipment (PSL 1 and PSL 2), Fifth Edition, April 2012. Global StandardsEquivalent Round
Definition(s)
Equivalent Round
Standard for comparing various shaped sections to round bars, used for determining the response to hardening characteristics when heat treating low-alloy and martensitic corrosion-resistant steels. Source: API SPEC 8C, Drilling and Production Hoisting Equipment (PSL 1 and PSL 2), Fifth Edition, April 2012. Global Standards Source:API SPECIFICATION 7K, Drilling and Well Servicing Equipment, Sixth Edition, December 2015. Global StandardsBearing-Load Rating
Definition(s)
Bearing-Load Rating
Calculated maximum load for bearings subjected to the primary load. Sources: API SPEC 8C, Drilling and Production Hoisting Equipment (PSL 1 and PSL 2), Fifth Edition, April 2012. Global StandardsWorking Load Limit (WLL)
Definition(s)
working load limit <lifting set>
Maximum mass or weight that a lifting component is designed to sustain in lifting service.
Source: API Standard 2CCU, Offshore Cargo Carrying Units, First Edition, August 2017. Global StandardsWorking Load Limit
A load value assigned to loose gear by the manufacturer that is a fraction of the breaking load value which should not be exceeded during use of BOP handling systems and equipment. Source: API SPEC 7K, Drilling and Well Servicing Equipment Upstream Segment, Fifth Edition, June 2010 (August 2010). Global Standards Source:API SPECIFICATION 7K, Drilling and Well Servicing Equipment, Sixth Edition, December 2015. Global StandardsWorking Load Limit
Working Load Limit (WLL) of the interchangeable components refers to the permissible load of these parts (e.g. shackles, hooks, chains, links etc.) without regard to the hoist load and/or dead load coefficient. It should be noted that the Working Load Limit (WLL) of an interchangeable component is not normally identical the Safe Working Load (SWL) of the lifting appliance, as the components have to be dimensioned in accordance with the local occurring forces. These forces are indicated in the rigging plans. Source: Rules for Classification and Construction, IV Industrial Services, 6 Offshore Technology, 9 Guideline for Personnel Transfers by Means of Lifting Appliances, Edition 2011, Germanischer Lloyd SE, Global StandardsWire Rope Design Factor
Definition(s)
Wire Rope Design Factor
The ratio between documented minimum breaking strength and the working load limit as applied to wire rope and slings. ] NOTE: This term should not be confused with design safety factor defined in 3.1.5. Source: API SPEC 7K, Drilling and Well Servicing Equipment Upstream Segment, Fifth Edition, June 2010 (August 2010). Global Standards Source:API SPECIFICATION 7K, Drilling and Well Servicing Equipment, Sixth Edition, December 2015. Global StandardsVibrator Hose
Definition(s)
Vibrator Hose
A flexible hose assembly used to convey high-pressure drilling liquids between two piping systems or between the mud-pump discharge outlet and the high-pressure mud piping system for the purpose of attenuating noise and/or vibration, or compensating for misalignment and/or thermal expansion. Source: API SPEC 7K, Drilling and Well Servicing Equipment Upstream Segment, Fifth Edition, June 2010 (August 2010). Global Standards Source:API SPECIFICATION 7K, Drilling and Well Servicing Equipment, Sixth Edition, December 2015. Global StandardsTIR
Test Unit
Definition(s)
Test Unit
Prototype unit upon which a design verification test is conducted. Source: API SPEC 7K, Drilling and Well Servicing Equipment Upstream Segment, Fifth Edition, June 2010 (August 2010). Global Standards Source:API SPECIFICATION 7K, Drilling and Well Servicing Equipment, Sixth Edition, December 2015. Global Standards Source: API SPEC 8C, Drilling and Production Hoisting Equipment (PSL 1 and PSL 2), Fifth Edition, April 2012. Global StandardsStatic Load
Definition(s)
Static Load
Operation that can change or affect the mechanical properties, including toughness, of the materials used in equipment. Source: API SPEC 7K, Drilling and Well Servicing Equipment Upstream Segment, Fifth Edition, June 2010 (August 2010). Global StandardsStatic Load
The load exerted on the BOP handling system by the static weight of the BOP stack.
Source:API SPECIFICATION 7K, Drilling and Well Servicing Equipment, Sixth Edition, December 2015. Global StandardsSnub-Line
Definition(s)
Snub-Line
Wire rope, one end of which is fastened to the end of a pipe tong handle attachment point and the other end secured to hold the tong stationary while the tong is in use. NOTE: Snub-lines do not work over a sheave or bend. Source: API SPEC 7K, Drilling and Well Servicing Equipment Upstream Segment, Fifth Edition, June 2010 (August 2010). Global Standards Source:API SPECIFICATION 7K, Drilling and Well Servicing Equipment, Sixth Edition, December 2015. Global StandardsSize Range
Definition(s)
Size Range
Range of tubular diameters to which an assembly is applicable. Source: API SPEC 7K, Drilling and Well Servicing Equipment Upstream Segment, Fifth Edition, June 2010 (August 2010). Global Standards Source:API SPECIFICATION 7K, Drilling and Well Servicing Equipment, Sixth Edition, December 2015. Global StandardsSize Range
Range of tubular diameters covered by an assembly. Source: API SPEC 8C, Drilling and Production Hoisting Equipment (PSL 1 and PSL 2), Fifth Edition, April 2012. Global StandardsSize Class
Definition(s)
Size Class
Designation of the dimensional interchangeability of equipment specified herein. Source: API SPEC 7K, Drilling and Well Servicing Equipment Upstream Segment, Fifth Edition, June 2010 (August 2010). Global Standards Source:API SPECIFICATION 7K, Drilling and Well Servicing Equipment, Sixth Edition, December 2015. Global StandardsSize Class
Designation by which dimensionally-interchangeable equipment of the same maximum load rating is identified. Source: API SPEC 8C, Drilling and Production Hoisting Equipment (PSL 1 and PSL 2), Fifth Edition, April 2012. Global StandardsRotary Hose
Definition(s)
Rotary Hose
A flexible hose assembly used to convey high-pressure drilling liquids between the top of the mud standpipe and the rotary swivel. Source: API SPEC 7K, Drilling and Well Servicing Equipment Upstream Segment, Fifth Edition, June 2010 (August 2010). Global Standards Source:API SPECIFICATION 7K, Drilling and Well Servicing Equipment, Sixth Edition, December 2015. Global StandardsRated Speed
Definition(s)
Rated Speed
Rate of rotation, motion, or velocity as specified by the manufacturer. Source: API SPEC 7K, Drilling and Well Servicing Equipment Upstream Segment, Fifth Edition, June 2010 (August 2010). Global Standards Source:API SPECIFICATION 7K, Drilling and Well Servicing Equipment, Sixth Edition, December 2015. Global StandardsRated Speed
Rated speed is the crankshaft revolutions per minute at which the rated power occurs as specified on the nameplate and in the Technical File of the marine diesel engine. Source: Resolution MEPC.177(58), amendments to the Technical Code on Control of Emission of Nitrogen Oxides from Marine Diesel Engines, 10 October 2008, International Maritime Organization. Regulatory GuidanceProof Load Test
Definition(s)
Proof Load Test <lifting sets>
A test performed on a lifting set to a specific multiple of the rated load.
Source: API Standard 2CCU, Offshore Cargo Carrying Units, First Edition, August 2017. Global StandardsProof Load Test <CCU>
A test performed on a CCU in which the unit’s pad eyes and primary structure is subjected to a specific load.
Source: API Standard 2CCU, Offshore Cargo Carrying Units, First Edition, August 2017. Global Standards