Glossary
Browse the IADC Lexicon alphabetically or by category. Get comprehensive definitions of drilling industry terms.
Stress-Relief Features
Definition(s)
Stress-Relief Features
Modification performed on rotary shouldered connections by removing the unengaged threads on the pin or box to make the joint more flexible and to reduce the likelihood of fatigue-cracking in highly stressed areas. Source: API SPEC 7-1, Specification for Rotary Drill Stem Elements, First Edition, March 2006 (Addendum April 2011). Global StandardsStriking Distance
Definition(s)
Striking Distance
The distance over which the final breakdown of the initial lightning stroke occurs.
Source: API RP 545 Recommended Practice for Lightning Protection of Aboveground Storage Tanks for Flammable or Combustible Liquids, First Edition, October 2009. Global StandardsString
Definition(s)
String
Assembly of individual tubular joints. EXAMPLES Casing, drill pipe, tubing, etc. Source: API RP 96, Deepwater Well Design and Construction, First Edition, March 2013. Global StandardsString Items
Definition(s)
String Items
String items are defined as items that are all integral parts of the conduit (“string”) used for production or injection of well effluents. The string is built by screwing together a variety of equipment items. Source: API STD 689, Collection and Exchange of Reliability and Maintenance Data for Equipment, First Edition, July 2007. Global StandardsStringers
Definition(s)
Stringers
Stringers are the uprights or sides of a ladder. Source: IMO MSC.1/Circ.1352, amendments to the Code of Safe Practice for Cargo Stowage and Securing (CSS Code), 30 June 2010, International Maritime Organization. Regulatory GuidanceStringer
Stringer means: .1 the frame of a ladder; or .2 the stiffened horizontal plating structure fitted on the side shell, transverse bulkheads and/or longitudinal bulkheads in the space. For the purpose of ballast tanks of less than 5 m width forming double side spaces, the horizontal plating structure is credited as a stringer and a longitudinal permanent means of access, if it provides a continuous passage of 600 mm or more in width past frames or stiffeners on the side shell or longitudinal bulkhead. Openings in stringer plating utilized as permanent means of access shall be arranged with guard rails or grid covers to provide safe passage on the stringer or safe access to each transverse web. Source: IMO Resolution MSC.158(78), amendments to the Technical provisions for means of access for inspections (Resolution MSC.133(76)), 20 May 2004, International Maritime Organization. Regulatory GuidanceStrip Lining
Definition(s)
Strip Lining
Strips of metal plates that are welded to the inside of the vessel wall for the purpose of protecting the vessel construction material from interaction with process fluids. Normally the strips are of a more corrosion resistant or erosion resistant alloy than the vessel wall and provide additional corrosion/erosion resistance. This is similar to plate lining except narrower strips are used instead of larger plates.
Source: API 510, Pressure Vessel Inspection Code: In-service Inspection, Rating, Repair, and Alteration, Tenth Edition, May 2014, with Addendum May 2017. Global StandardsStrip Lining
Strips of metal plates that are welded to the inside of the vessel wall. Normally the strips are of a more corrosion resistant or erosion resistant alloy than the vessel wall and provide additional corrosion/erosion resistance. This is similar to plate lining except strips are used instead of larger plates. Source: API 510, Pressure Vessel Inspection Code: In-Service Inspection, Rating, Repair, and Alteration Downstream Segment, Ninth Edition, June 2006. Global StandardsStripper Head
Definition(s)
Stripper Head
Blowout prevention device consisting of a gland and packing arrangement bolted to a wellhead. Used to seal annular space between tubing and casing. Source: IADC UBO / MPD Glossary, December 2011. Global StandardsStripper Rubbers
Definition(s)
Stripper Rubbers
Internal component of rotating head used to strip pipe in and out of hole, available for drill pipe and casing sizes, and may be polyurethane composition where required to suit application / conditions e.g., high temperature service, or in certain drilling fluid applications where standard elastomers are inappropriate. Source: IADC UBO / MPD Glossary, December 2011. Global StandardsStripper Well
Definition(s)
Stripper Well
A well having minimal hydrocarbon production. Source: IADC UBO / MPD Glossary, December 2011. Global StandardsStripper Well
Stripper Well―shall have the ordinary meaning as that term is generally understood in the oil and gas industry, but shall not be construed to include naturally flowing or artificial gas-lift oil wells. Source: Natural Resources, Office of Conservation – General Operations, Louisiana Administrative Code, Title 43, Part XIX, March 2013. RegulationsStripper Well Incentive Tax Rates
Definition(s)
Stripper Well Incentive Tax Rates
“Stripper well incentive tax rates” means the tax rates set for stripper well properties by NMSA 1978, Sections 7-29-4 and 7-31-4. Source: Oil and Gas, New Mexico Administrative Code Title 19, Chapter 15, January 2013. RegulationsStripper Well Property
Definition(s)
Stripper Well Property
“Stripper well property” means an oil or gas producing property that the taxation and revenue department assigns a single production unit number (PUN) and:- if an oil producing property, produced a daily average of less than 10 barrels of oil per eligible well per day for the preceding calendar year;
- if a gas producing property, produced a daily average of less than 60,000 cubic feet of gas per eligible well per day during the preceding calendar year; or
- if a property with wells that produce both oil and gas, produced a daily average of less than 10 barrels of oil per eligible well per day for the preceding calendar year, as determined by converting the volume of gas the well produced to barrels of oil by using a ratio of 6000 cubic feet to one barrel of oil.1
Stripping
Definition(s)
Stripping
A procedure for running or pulling pipe from the well bore with pressure in the annulus. Source: API RP 59, Recommended Practice for Well Control Operations, Second Edition, May 2006. Global StandardsStripping
Adding or removing pipe from a pressured wellbore while controlling flow from the wellbore. Source: API SPEC 16RCD, Specification for Drill Through Equipment—Rotating Control Devices, Upstream Segment, First Edition, February 2005. Global StandardsStripping
Adding or removing drill pipe into a live or pressurized well after exceeding pipe light depth. Source: IADC UBO / MPD Glossary, December 2011. Global StandardsStripping
“Stripping” means pulling or running pipe under pressure through a resilient sealing element and may also include the removing of rods and tubing from the well at the same time. [Mich. Admin. Code R 408 (2013)]. Source: Oil and Gas Drilling and Servicing Operations, Michigan Administrative Code R 408, February 8, 2013. RegulationsStripping In
Definition(s)
Stripping In
The process of lowering the drill stem into a well when the well is live. Source: IADC UBO / MPD Glossary, December 2011. Global StandardsStripping Out
Definition(s)
Stripping Out
The process of raising the drill string out of the wellbore when the well is live. Source: IADC UBO / MPD Glossary, December 2011. 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 StandardsStroke
Definition(s)
Stroke.
One current component of a lightning flash. The number of strokes per flash is typically three to four, but may be as low as one or as high as 30 (Uman, All About Lightning, p. 41). Source: API RP 545 Recommended Practice for Lightning Protection of Aboveground Storage Tanks for Flammable or Combustible Liquids, First Edition, October 2009. Global StandardsStroke
Total vertical movements (upward and downward) of the riser relative to the vessel which is also the travel of the riser tensioner.- NOTE: Stroke is affected by environmental loads, functional loads (i.e. top tension, temperature and mean static vessel offset) and pressure.
Stroke
Total upward and downward vertical movements of the riser relative to the vessel, i.e. travel of the riser tensioner, draw works and slick joint.- NOTE: It includes effects from environmental loads, functional loads (i.e. top tension, temperature and mean static vessel offset) and pressure.
Structural Analysis
Definition(s)
Structural Analysis
Process or algorithm for determining action effects from a given set of actions. NOTE 1 Structural analyses are performed at three levels [global analysis of an entire structure, analysis of part of a structure (e.g. a leg), local analysis of a structural member and local analysis of a structural component] using different structural models. NOTE 2 Adapted from ISO 19902:2007, definition 3.51. Source: ISO 19905-1:202, Petroleum and natural gas industries – Site-specific assessment of mobile offshore units – Part 1: Jack-ups. Global StandardsStructural Capacity
Definition(s)
Structural Capacity
Maximum load(s) the connector can sustain without exceeding the allowables for normal, extreme, or survival conditions and still maintain functional requirements.
Source: API Technical Report 17TR7, Verification and Validation of Subsea Connectors, First Edition, April 2017. Global StandardsStructural Casing
Definition(s)
Structural Casing
The outer string of large-diameter, heavy-wall pipe installed in wells drilled from floating installations to resist the bending moments imposed by the marine riser and to help support the wellhead installed on the conductor casing. Source: API RP 59, Recommended Practice for Well Control Operations, Second Edition, May 2006. Global StandardsStructural Casing
The outer string of large diameter, heavy-wall pipe installed in wells drilled from floating installations to isolate very shallow sediments from subsequent drilling and to resist the bending moments imposed by the marine riser and to help support the wellhead installed on the conductor casing. Source: API RP 64, Recommended Practice for Diverter Systems Equipment and Operations, Second Edition, November 2001 (March 1, 2007). Global StandardsStructural Casing
"Structural casing" means a short string of large diameter pipe that is set by driving, jetting, or drilling to support unconsolidated shallow sediments, provide hole stability for initial drilling operations, and provide anchorage for a diverter system. Source: Alaska Oil and Gas Conservation Commission, Definitions, Alaska Admin. Code tit. 20, § 25.990, December 7, 2012. RegulationsStructural Component
Definition(s)
Structural Component
Physically distinguishable part of a structure. [ISO 19900:2002]. Source: ISO 19901-7:2013, Petroleum and natural gas industries – Specific requirements for offshore structures – Part 7: Stationkeeping systems for floating offshore structures and mobile offshore units. Global Standards Source: ISO 19900:2013, Petroleum and natural gas industries – General requirements for offshore structures. Global StandardsStructural Component, Component
Physically distinguishable part of a member cross-section of uniform yield strength. NOTE The cross-section of a non-tubular member is usually comprised of several structural components. A component consists of only one material. Where a plate component is reinforced by another piece of plating, the reinforcement can be of a different yield strength. See also further discussion in A.12.1.1. Source: ISO 19905-1:202, Petroleum and natural gas industries – Site-specific assessment of mobile offshore units – Part 1: Jack-ups. Global StandardsStructural Component, Member
Physically distinguishable part of a braced structure connecting two joints. NOTE 1 A structural member can also be defined as the leg of a non-truss leg jack-up. NOTE 2 See also further discussion in A.12.1.1. Source: ISO 19905-1:202, Petroleum and natural gas industries – Site-specific assessment of mobile offshore units – Part 1: Jack-ups. Global StandardsStructural Component, Structural Member
Physically distinguishable part of a braced structure connecting two joints. NOTE 1 A structural member can also be defined as the leg of a non-truss leg jack-up. NOTE 2 See also further discussion in A.12.1.1. Source: ISO 19905-1:202, Petroleum and natural gas industries – Site-specific assessment of mobile offshore units – Part 1: Jack-ups. Global StandardsStructural Integrity
Definition(s)
Structural integrity
Structural integrity includes the following:- structural soundness;
- structural strength;
- stability;
- fitness for purpose;
- mechanical integrity;
- systems integrity; in connection with:
- the containment of:
- petroleum; or
- a greenhouse gas substance; or
- any other substance; or
- the health and safety of persons engaged in:
- offshore petroleum operations (within the meaning of Part 6.9); or
- offshore greenhouse gas operations (within the meaning of Part 6.9). For the purposes of paragraph (f), systems integrity includes the integrity of the following:
- electrical systems;
- electronic systems;
- hydraulic systems;
- chemical systems;
- dynamic positioning systems;
- other systems.
Structural Integrity Law
Definition(s)
Structural integrity law
Structural integrity law means the provisions of this Act or the regulations to the extent to which the provisions relate to the structural integrity of:- facilities (within the meaning of Schedule 3); or
- wells; or
- well-related equipment.
Structural Integrity Management System
Definition(s)
Structural Integrity Management System
structured methodology, consisting of a multi-step cyclic activity, including feedback, intended to assure the life and functionality of a structure Note 1 to entry: Typical steps include data collection, data evaluation, development of an inspection strategy, development and execution of an inspection programme, and consequent remedial works. Note 2 to entry: Structural integrity management is also known as SIM. Source: ISO 19900:2013, Petroleum and natural gas industries – General requirements for offshore structures. Global StandardsStructural Minimum Thickness
Definition(s)
Structural Minimum Thickness
Minimum required thickness without corrosion allowance, based on the mechanical loads other than pressure that result in longitudinal stress. See 7.6.- NOTE: The thickness is either determined from a standard chart or engineering calculations. It does not include thickness for corrosion allowance or mill tolerances.