Glossary
Browse the IADC Lexicon alphabetically or by category. Get comprehensive definitions of drilling industry terms.
Bend Stiffener Cap
Definition(s)
Bend stiffener cap
Structural component of some bend stiffener designs comprising a cylindrical metallic shell that fits externally around part of the bend stiffener length adjacent to the bend stiffener base. NOTE An example of a bend stiffener cap, for a particular bend stiffener configuration, is shown in Figure 1. Source: API RP 17L2, Recommended Practice for Flexible Pipe Ancillary Equipment, First Edition, March 2013. Global StandardsBend Stiffener Body
Definition(s)
Bend Stiffener Body
Polymeric part of a bend stiffener that provides extra stiffness to the flexible pipe to prevent it from overbending. NOTE The bend stiffener body, for a particular bend stiffener configuration, is shown in Figure 1. Source: API RP 17L2, Recommended Practice for Flexible Pipe Ancillary Equipment, First Edition, March 2013. Global StandardsBend Stiffener Body
Polymeric part of a bend stiffener that provides extra stiffness to the flexible pipe to prevent it from overbending. NOTE The bend stiffener body, for a particular bend stiffener configuration, is shown in Figure 1. Source: API SPEC 17L1, Specification for Flexible Pipe Ancillary Equipment, First Edition, March 2013. Global StandardsBend Stiffener Base
Definition(s)
Bend Stiffener Base
Face of the interface structure on the support structure side at which the bend stiffener begins. Source: API RP 17L2, Recommended Practice for Flexible Pipe Ancillary Equipment, First Edition, March 2013. Global StandardsBend Stiffener Base
Face of the interface structure on the support structure side at which the bend stiffener begins. Source: API SPEC 17L1, Specification for Flexible Pipe Ancillary Equipment, First Edition, March 2013. Global StandardsVertebra
Definition(s)
Bend restrictor element or vertebra
Unit part of bend restrictor, of which a series are linked together to form the complete length of the bend restrictor. Source: API RP 17L2, Recommended Practice for Flexible Pipe Ancillary Equipment, First Edition, March 2013. Global StandardsBend Restrictor Element
Definition(s)
Bend restrictor element or vertebra
Unit part of bend restrictor, of which a series are linked together to form the complete length of the bend restrictor.1Source(s)
1. API RP 17L2, Recommended Practice for Flexible Pipe Ancillary Equipment, First Edition, March 2013. Global Standards
Batch
Definition(s)
Batch
Quantity of product produced during one operation. Source: API RP 17L2, Recommended Practice for Flexible Pipe Ancillary Equipment, First Edition, March 2013. Global StandardsBatch
Quantity of product produced during one operation. Source: API SPEC 17L1, Specification for Flexible Pipe Ancillary Equipment, First Edition, March 2013. Global StandardsBanding
Definition(s)
Banding
Device used to secure mechanical protection to the flexible pipe. Source: API RP 17L2, Recommended Practice for Flexible Pipe Ancillary Equipment, First Edition, March 2013. Global StandardsBanding
Device used to secure mechanical protection to the flexible pipe. Source: API SPEC 17L1, Specification for Flexible Pipe Ancillary Equipment, First Edition, March 2013. Global StandardsBallast Module
Definition(s)
Ballast module
Negatively buoyant component of which a number are used at discrete points over a length of flexible pipe to provide added weight. Source: API RP 17L2, Recommended Practice for Flexible Pipe Ancillary Equipment, First Edition, March 2013. Global StandardsAncillary Component
Definition(s)
Ancillary component
Component that is attached to the flexible pipe in order to perform one or more of the following functions:- to control the flexible pipe behavior;
- to provide a structural transition between the flexible pipe and adjacent structures;
- to attach other structures to the flexible pipe;
- to protect or repair the flexible pipe;
- to provide a seal along the flexible pipe length.
Anchor Base
Definition(s)
Anchor Base
Structure used to secure one end of a tether to the seabed. Source: API RP 17L2, Recommended Practice for Flexible Pipe Ancillary Equipment, First Edition, March 2013. Global StandardsAnchor Base
Structure used to secure one end of a tether to the seabed. Source: API SPEC 17L1, Specification for Flexible Pipe Ancillary Equipment, First Edition, March 2013. Global StandardsInjection Systems
Definition(s)
Injection systems
Injection systems involve injection of water or gas into the sub-surface for disposal or stimulation purposes. Water-injection systems include injection of de-aerated seawater, untreated seawater, chlorinated seawater, produced water, aquifer water and combinations and mixing of different waters. NOTE Aquifer water comes from an underground layer of water-bearing, permeable rock from which ground water can be extracted. This water can be used for injection into oil-bearing reservoirs. Source: API RP 17A Addendum 1, Design and Operation of Subsea Production Systems—General Requirements and Recommendations, December 2010. Global StandardsSWC
Definition(s)
SWC
Stepwise cracking. Source: API RP 17A Addendum 1, Design and Operation of Subsea Production Systems—General Requirements and Recommendations, December 2010. Global StandardsSWC
Step-wise cracking Source: ISO 21457:2010, Petroleum and natural gas industries — Materials selection and corrosion control for oil and gas production systems, First Edition,September 2010. Global StandardsMIC
Definition(s)
MIC
Microbiologically influenced corrosion. Source: API RP 17A Addendum 1, Design and Operation of Subsea Production Systems—General Requirements and Recommendations, December 2010. Global StandardsMIC
minimum ignition current ratio. API RP 500, Recommended Practice for Classification of Locations for Electrical Installations at Petroleum Facilities Classified as Class I, Division 1 and Division 2, Third Edition, December 2012, Global StandardsMIC
The ratio of the minimum current required from an inductive spark discharge to ignite the most easily ignitable mixture of a gas or vapor, divided by the minimum current required from an inductive spark discharge to ignite methane under the same test conditions. API RP 500, Recommended Practice for Classification of Locations for Electrical Installations at Petroleum Facilities Classified as Class I, Division 1 and Division 2, Third Edition, December 2012, Global StandardsMIC
Microbiologically induced corrosion. Source: ISO 21457:2010, Petroleum and natural gas industries — Materials selection and corrosion control for oil and gas production systems, First Edition,September 2010. Global StandardsHIC
Definition(s)
HIC
Hydrogen induced cracking. Source: API 570, Piping Inspection Code: In-service Inspection, Rating, Repair, and Alteration of Piping Systems, Fourth Edition, February 2016, with Addendum May 2017. Global Standards Source: API RP 17A Addendum 1, Design and Operation of Subsea Production Systems—General Requirements and Recommendations, December 2010. Global Standards Source: API RP 17B, Recommended Practice for Flexible Pipe, Fourth Edition, July 2008. Global Standards Source: ISO 21457:2010, Petroleum and natural gas industries — Materials selection and corrosion control for oil and gas production systems, First Edition,September 2010. Global StandardsHIC
Hydrogen-induced cracking. Source: API SPEC 17J, Specification for Unbonded Flexible Pipe, Third Edition, July 2008. Global StandardsHIC
Planar cracking that occurs in carbon and low alloy steels when atomic hydrogen diffuses into the steel and then combines to form molecular hydrogen at trap sites- NOTE: Cracking results from the pressurization of trap sites by hydrogen. No externally applied stress is needed for the formation of hydrogen-induced cracks. Trap sites capable of causing HIC are commonly found in steels with high impurity levels that have a high density of planar inclusions and/or regions of anomalous microstructure (e.g. banding) produced by segregation of impurity and alloying elements in the steel. This form of hydrogen-induced cracking is not related to welding.
HB
Definition(s)
HB
Brinell hardness. Source: API RP 17A Addendum 1, Design and Operation of Subsea Production Systems—General Requirements and Recommendations, December 2010. Global Standards Source: ISO 21457:2010, Petroleum and natural gas industries — Materials selection and corrosion control for oil and gas production systems, First Edition,September 2010. Global StandardsType 25Cr Duplex
Definition(s)
Type 25Cr duplex
Ferritic/austenitic stainless steel alloys with 40 u PREN u 45. EXAMPLES UNS S32750 and S32760 steels. Source: API RP 17A Addendum 1, Design and Operation of Subsea Production Systems—General Requirements and Recommendations, December 2010. Global Standards Source: ISO 21457:2010, Petroleum and natural gas industries — Materials selection and corrosion control for oil and gas production systems, First Edition,September 2010. Global StandardsType 22Cr Duplex
Definition(s)
Type 22Cr duplex
Ferritic/austenitic stainless steel alloys with 30 u PREN u 40 and Mo u 2,0 % mass fraction. EXAMPLES UNS S31803 and S32205 steels. Source: API RP 17A Addendum 1, Design and Operation of Subsea Production Systems—General Requirements and Recommendations, December 2010. Global Standards Source: ISO 21457:2010, Petroleum and natural gas industries — Materials selection and corrosion control for oil and gas production systems, First Edition,September 2010. Global StandardsType 6Mo
Definition(s)
Type 6Mo
Austenitic stainless steel alloys with PREN W 40 and Mo alloying W 6,0 % mass fraction, and nickel alloys with Mo content in the range 6 % mass fraction to 8 % mass fraction. EXAMPLES UNS S31254, N08367 and N08926 alloys. Source: API RP 17A Addendum 1, Design and Operation of Subsea Production Systems—General Requirements and Recommendations, December 2010. Global StandardsType 6Mo
Austenitic stainless steel alloys with PREN W 40 and a nominal Mo alloying content of 6 % mass fraction, and nickel alloys with Mo content in the range 6 % to 8 % mass fraction EXAMPLE UNS S31254; UNS N08367; UNS N08926. Source: ISO 21457:2010, Petroleum and natural gas industries — Materials selection and corrosion control for oil and gas production systems, First Edition,September 2010. Global StandardsSweet Service
Definition(s)
Sweet service
Service in an H2S-free (sweet) fluid. Source: API RP 17A Addendum 1, Design and Operation of Subsea Production Systems—General Requirements and Recommendations, December 2010. Global StandardsSweet service
Service conditions at the design pressure which have a H2S content less than that specified by ISO 15156 (all parts). Source: API SPEC 17J, Specification for Unbonded Flexible Pipe, Third Edition, July 2008. Global StandardsSour Service
Definition(s)
Sour Service
Service conditions with H2S content exceeding the minimum specified by NACE MR0175/ISO 15156 at the design pressure. Source: API Standard 2RD, Dynamic Risers for Floating Production Systems, Second Edition, September 2013. Global StandardsSour Service
Service in an H2S-containing (sour) fluid. NOTE In this part of ISO 13628, “sour service” refers to conditions where the H2S content is such that restrictions as specified by ISO 15156 (all parts) apply. Source: API RP 17A Addendum 1, Design and Operation of Subsea Production Systems—General Requirements and Recommendations, December 2010. Global StandardsSour Service
Service conditions with H2S content exceeding the minimum specified by ISO 15156 (all parts) at the design pressure. Source: API RP 17G, Recommended Practice for Completion/Workover Risers, Second Edition, July 2006 (Reaffirmed April 2011). Global StandardsSour Service
Exposure to oilfield environments that contain H2S and can cause cracking of materials by the mechanisms addressed in ISO 15156. NOTE Adapted from ISO 15156-1:2001. Source: API SPEC 14A, Specification for Subsurface Safety Valve Equipment, Eleventh Edition, October 2005 (Reaffirmed June 2012). Global StandardsType 316
Definition(s)
Type 316
Austenitic stainless steel alloys of type UNS S31600/S31603. Source: API RP 17A Addendum 1, Design and Operation of Subsea Production Systems—General Requirements and Recommendations, December 2010. Global Standards Source: ISO 21457:2010, Petroleum and natural gas industries — Materials selection and corrosion control for oil and gas production systems, First Edition,September 2010. Global StandardsPREN
Definition(s)
PREN
Pitting resistance equivalent number. Source: ISO 21457:2010, Petroleum and natural gas industries — Materials selection and corrosion control for oil and gas production systems, First Edition,September 2010. Global StandardsPREN (FPREN)
Number, developed to reflect and predict the pitting resistance of a stainless steel, based upon the proportions of Cr, Mo, W and N in the chemical composition of the alloy NOTE 1 For the purposes of this International Standard, FPREN is calculated from Equation (1): FPREN = wCr + 3,3(wMo + 0,5wW) + 16wN (1) where wCr is the percent (mass fraction) of chromium in the alloy; wMo is the percent (mass fraction) of molybdenum in the alloy; wW is the percent (mass fraction) of tungsten in the alloy; wN is the percent (mass fraction) of nitrogen in the alloy. NOTE 2 Adapted from ISO 15156-3:2009, definition 3.10, and ISO 15156-3:2009, 6.3. Source: ISO 21457:2010, Petroleum and natural gas industries — Materials selection and corrosion control for oil and gas production systems, First Edition,September 2010. Global StandardsPitting resistance equivalent number (PREN)
Number developed to reflect and predict the pitting resistance of a stainless steel, based on the proportions of Cr, Mo, W and N in the chemical composition of the alloy. NOTE This number is based on observed resistance to pitting of CRAs in the presence of chlorides and oxygen, e.g. seawater, and is not directly indicative of the resistance to produced oil and gas environments. FPREW = wCr + 3,3(wMo + 0,5wW) + 16wN where wCr is the mass fraction of chromium in the alloy, expressed as a percentage of the total composition; wMo is the mass fraction of molybdenum in the alloy, expressed as a percentage of the total composition; wW is the mass fraction of tungsten in the alloy, expressed as a percentage of the total composition; wN is the mass fraction of nitrogen in the alloy, expressed as a percentage of the total composition.1 Source: API RP 17A Addendum 1, Design and Operation of Subsea Production Systems—General Requirements and Recommendations, December 2010. Global StandardsPitting Resistance Equivalent Number
Definition(s)
Pitting Resistance Equivalent Number (FPREN)
Number developed to reflect and predict the pitting resistance of a stainless steel, based on the proportions of Cr, Mo, W and N in the chemical composition of the alloy. NOTE This number is based on observed resistance to pitting of CRAs in the presence of chlorides and oxygen, e.g. seawater, and is not directly indicative of the resistance to produced oil and gas environments. FPREW = wCr + 3,3(wMo + 0,5wW) + 16wN where wCr is the mass fraction of chromium in the alloy, expressed as a percentage of the total composition; wMo is the mass fraction of molybdenum in the alloy, expressed as a percentage of the total composition; wW is the mass fraction of tungsten in the alloy, expressed as a percentage of the total composition; wN is the mass fraction of nitrogen in the alloy, expressed as a percentage of the total composition. Source: API RP 17A Addendum 1, Design and Operation of Subsea Production Systems—General Requirements and Recommendations, December 2010. Global StandardsPitting Resistance Equivalent Number(FPREN)
Number, developed to reflect and predict the pitting resistance of a stainless steel, based upon the proportions of Cr, Mo, W and N in the chemical composition of the alloy NOTE 1 For the purposes of this International Standard, FPREN is calculated from Equation (1): FPREN = wCr + 3,3(wMo + 0,5wW) + 16wN (1) where wCr is the percent (mass fraction) of chromium in the alloy; wMo is the percent (mass fraction) of molybdenum in the alloy; wW is the percent (mass fraction) of tungsten in the alloy; wN is the percent (mass fraction) of nitrogen in the alloy. NOTE 2 Adapted from ISO 15156-3:2009, definition 3.10, and ISO 15156-3:2009, 6.3. Source: ISO 21457:2010, Petroleum and natural gas industries — Materials selection and corrosion control for oil and gas production systems, First Edition,September 2010. Global StandardsLow-alloy Steel
Definition(s)
Low-alloy steel
Steels containing a total alloying element content of less than 5 % mass fraction, but more than that for carbon steel. EXAMPLES AISI 4130, AISI 8630, ASTM A182 Grade F22[12] are examples of low alloy steels. Source: API RP 17A Addendum 1, Design and Operation of Subsea Production Systems—General Requirements and Recommendations, December 2010. Global Standards Source: ISO 21457:2010, Petroleum and natural gas industries — Materials selection and corrosion control for oil and gas production systems, First Edition,September 2010. Global StandardsLow-alloy steel
Steel containing less than 5% total alloying elements, but more than specified for carbon steel. Although not generally considered a low alloy steel, steels with less than 11% chromium shall be included in this category. Source: API SPEC 16C, Specification for Choke and Kill Systems, First Edition, January 1993 (Reaffirmed 2001). Global StandardsCarbon Steel
Definition(s)
Carbon steel
Alloy of carbon and iron containing up to 2 % mass fraction carbon, up to 1,65 % mass fraction manganese and residual quantities of other elements, except those intentionally added in specific quantities for deoxidation (usually silicon and/or aluminium) NOTE Carbon steels used in the petroleum industry usually contain less than 0,8 % mass fraction carbon. [ISO 15156-1:2009, 3.3] API RP 17A Addendum 1, Design and Operation of Subsea Production Systems—General Requirements and Recommendations, December 2010. Global Standards Source: ISO 21457:2010, Petroleum and natural gas industries — Materials selection and corrosion control for oil and gas production systems, First Edition,September 2010. Global StandardsCarbon steel
Alloy of carbon and iron containing a maximum of 2 % mass fraction carbon, 1,65 % mass fraction manganese, and residual quantities of other elements, except those intentionally added in specific quantities for deoxidation (usually silicon and/or aluminium). API SPEC 6A, Specification for Wellhead and Christmas Tree Equipment, Twentieth Edition, October 2010 (Addendum November 2012). Global StandardCarbon steel
An alloy of carbon and iron containing a maximum of 2% carbon, 1.65% manganese, and residual quantities of other elements, except those intentionally added in specific quantities for deoxidation (usually silicon and/or aluminum). API SPEC 16C, Specification for Choke and Kill Systems, First Edition, January 1993 (Reaffirmed 2001). Global StandardsJoint
Definition(s)
Joint
Means of connecting two or more components- EXAMPLE: Plain pipe to a fitting, or plain pipe to plain pipe.
Joint
A section of the structural member including the coupling and guidance devices is called a “joint”; the associated sections of lines are also called joints. Source: API RP 17A, Design and Operation of Subsea Production Systems—General Requirements and Recommendations, Fourth Edition, Reaffirmed 2011. Global StandardsWorkover Control System
Definition(s)
WOCS
The WOCS, also commonly referred to as the installation/workover riser package, provides the means to remotely control/monitor all of the required functions on the C/WO equipment, subsea tree and downhole equipment during the various phases of the C/WO operation. The WOCS usually consists of the following components: pumping unit to provide hydraulic power; main control panel; remote control panel on the drill floor; process shutdown panel near the production test equipment; emergency shutdown panels at main escape routes; umbilical(s) on powered winch(es). Source: API RP 17A, Design and Operation of Subsea Production Systems—General Requirements and Recommendations, Fourth Edition, Reaffirmed 2011. Global StandardsRigid-pipe Non-integral Riser
Definition(s)
Rigid-pipe non-integral riser
The lines in a non-integral riser can be run and retrieved separately from each other and from the main structural member. A non-integral riser includes a tensioned central structural member which may carry fluids or perform other functions besides providing structural support and guidance to lines. The structural member is fitted with support/guidance devices to locate and laterally guide individual lines. The two ends of the structural member are fitted with the two halves of a coupling. A section of the structural member including the coupling and guidance devices is called a “joint”; the associated sections of lines are also called joints. The two ends of each line joint are fitted with mechanical/pressure couplings, typically threaded box and pin, independent of the central pipe coupling. Other lines are installed individually after the structural member is installed and tensioned. They are retrieved individually before the structural member is retrieved. This design has the advantages of simplicity and of permitting the retrieval of a single line (e.g. for repair/replacement) without requiring the shut-in and retrieval of the whole system. It has the disadvantage of being slow to run or retrieve. Source: API RP 17A, Design and Operation of Subsea Production Systems—General Requirements and Recommendations, Fourth Edition, Reaffirmed 2011. Global StandardsRiser Joint
Definition(s)
Riser Joint
One section of the riser string having the main tube fitted with a box and pin coupling, choke, kill, and auxiliary lines (optional), and brackets, clamps, thrust collars, and buoyancy modules, as applicable.
Source: API Specification 16Q, Design, Selection, Operation, and Maintenance of Marine Drilling Riser Systems, Second Edition, April 2017. Global Standards