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Sealing Element

Device preventing passage (i.e. communication) of liquid and/or gas across the interface in which it is placed.

Source:API SPECIFICATION 19TT, Specification for Downhole Well Test Tools and Related Equipment, First Edition, October 2016. Global Standards

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Seamless Pipe

Tubular product fabricated without a welded seam. NOTE Typically manufactured in a hot forming process by extrusion or drawing which can be followed by cold sizing or finishing to the desired shape, dimensions and properties. Source: API Standard 2RD, Dynamic Risers for Floating Production Systems, Second Edition, September 2013. Global Standards

Seamless Pipe

Wrought steel tubular product made without a welded seam. NOTE Seamless pipe is manufactured by hot-working steel and, if necessary, by subsequently cold finishing the hot-worked tubular product to produce the desired shape, dimensions and properties. Source: API RP 5A5, Field Inspection of New Casing, Tubing, and Plain-end Drill Pipe, Reaffirmed August 2010. Global Standards  

Seamless Pipe

Wrought steel tubular product made without a weld seam. Source: API RP 7G-2, Recommended Practice for Inspection and Classification of Used Drill Stem Elements, First Edition, August 2009. Global Standards  

Seamless Pipe

Tubular product made without a welded seam, manufactured in a hot-forming process using an extrusion or drawing process that can be followed by cold sizing or cold finishing to produce the desired shape, dimensions and properties. Source: API RP 17G, Recommended Practice for Completion/Workover Risers, Second Edition, July 2006 (Reaffirmed April 2011). Global Standards  

Seamless Pipe

Wrought steel tubular product made without a weld seam. NOTE It is manufactured by hot-working steel, and if necessary, by subsequently cold-working or heat-treating, or a combination of these operations, to produce the desired shape, dimensions and properties. Source: API SPEC 5CT, Specification for Casing and Tubing, Upstream Segment, Ninth Edition, July 2011 (Errata September 2012). Global Standards  

Seamless Pipe

Wrought steel tubular product made without a weld seam. NOTE It is manufactured by hot working and, if necessary, by subsequently cold-working or heat-treating, or a combination of these operations, to produce the desired shape, dimensions and properties. [ISO 11960:2004, definition 4.1.37]. Source: API SPEC 5DP, Specification for Drill Pipe, First Edition, August 2009. Global Standards

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Search for Cause

The search of a specific individual, their vehicle or their possessions, which is suspected of committing a violation of company policies. Source: API RP 781 Security Plan Methodology for the Oil and Natural Gas Industries.1^st Ed. September 2016. Global Standards

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Seat, Casing

Designed to ensure that damage or breakage does not result from a hard shut in. Source: IADC UBO / MPD Glossary, December 2011. Global Standards

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Secant modulus

Slope of line drawn through the origin of a stress strain curve and intersecting a point on the stress strain curve corresponding to specified strain. Source: API RP 17L2, Recommended Practice for Flexible Pipe Ancillary Equipment, First Edition, March 2013. Global Standards  

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Secondary Barrier

Term used to back-up to the first barrier (i.e., the BOP system, casing, casing cement, and the wellhead collectively referred to as the secondary barrier envelope). Source: ABS Guide for Classification and Certification of Managed Pressure Drilling Systems, September 2017. Global Standards

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Secondary containment

An impermeable physical barrier specifically designed to prevent release into the environment of materials that have breached primary containment. Secondary containment systems include, but are not limited to, tank dykes, curbing around process equipment, drainage collection systems into segregated oily drain systems, the outer wall of double walled tanks etc. Source: OGP Report No. 456, Process Safety – Recommended Practice on Key Performance Indicators, International Association of Oil & Gas Producers, November 2011. Global Standards  

Secondary containment

An impermeable physical barrier specifically designed to prevent release of materials into the environment that have already breached primary containment (i.e. an LOPC). Secondary containment systems include, but are not limited to, tank dykes, curbing around process equipment, drainage collection systems into segregated oily drain systems, the outer wall of double walled tanks, etc. Source: OGP Report No. 456, Process Safety – Recommended Practice on Key Performance Indicators, International Association of Oil & Gas Producers, November 2011. Global Standards  

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Secondary Damage

Damage to units or to their electrical installations, which can result as an indirect consequence of a lightning strike to a unit or to its immediate vicinity. A path to earth of low resistance may not prevent secondary damage, which may occur as a result of high values of induced, or resistance drop voltages produced by the passage of lightning currents. Source: IEC 61892-6, Mobile and fixed offshore units – Electrical installations – Part 6: Installation, Third Edition, December  2013. Global Standards Source: IEC 61892-6, Mobile and fixed offshore units – Electrical installations – Part 6: Installation. Global Standards

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Secondary Equipment

Piece of equipment that can normally be isolated from the well fluid or well pressure. Source: API SPEC 6A, Specification for Wellhead and Christmas Tree Equipment, Twentieth Edition, October 2010 (Addendum November 2012). Global Standards

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Secondary Explosive

A high explosive that is less sensitive than a primary explosive to heat and shock. Also referred to as secondary high explosive. Source: API RP 67, Recommended Practice for Oilfield Explosives Safety, Upstream Segment, Second Edition, May 2007. Global Standards

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Secondary Grade of Release

Release which is not expected to occur in normal operation and, if it does occur, is likely to do so only infrequently and for short periods. Source: IEC 61892-7, Mobile and fixed offshore units – Electrical installations – Part 7: Hazardous areas. Global Standards

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Secondary Load

Load induced by structural deformation (or the prevention thereof) in the riser which is necessary to satisfy the laws of compatibility of strain and deformation. NOTE The internal forces induced by a secondary load diminish when yielding occurs. Secondary loads do not have to be taken into account where they do not affect the resistance of the member/component to resist other loads. Preload of bolts in flanges is an example. During make-up of a flange, the torque/tension applied by the tool on the bolts is primary, but after make-up, the residual bolt preload is secondary. EXAMPLE An example of a secondary load is the bending caused in the C/WO riser during operation within the drilling riser due to flex joint/ball joint angles. Bending moments that exceed yield, in this case, do not generally cause excessive yielding and failure. Other examples are differential temperature in restrained sections and residual stresses after welding. Source: API RP 17G, Recommended Practice for Completion/Workover Risers, Second Edition, July 2006 (Reaffirmed April 2011). Global Standards

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Secondary marking

Secondary marking is defined as the marking used within a major system or location to identify components such as valves, hydraulically operated components, local tapping points used for sensing equipment, probes, etc. A character height of 50 mm (1,969 in) to 150 mm (5,906 in) should be used. Smaller sizes may be used when the specified size is impractical. Source: API RP 17A, Design and Operation of Subsea Production Systems—General Requirements and Recommendations, Fourth Edition, Reaffirmed 2011. Global Standards  

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Secondary Means of Escape

Fixed stairways or fixed ladders of non-combustible construction or portable flexible ladders, knotted manropes, or other devices, approved by the regulatory agency. Source: API RP 14G, Recommended Practice for Fire Prevention and Control on Fixed Open-type Offshore Production Platforms: Upstream Segment, Fourth Edition, April 2007. Global Standards

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Secondary Method, of Evacuation

Method of leaving the installation in an emergency which can be carried out in a fully controlled manner under the direction of the person in charge, independent of external support. Source: ISO 15544:2000, Petroleum and natural gas industries – Offshore production installations – Requirements and guidelines for emergency. Global Standards

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Secondary Process Piping

Process piping located downstream of a block valve that can be valved-off without significantly affecting the process unit operability is commonly referred to as secondary process piping. Often, secondary process piping is small-bore piping (SBP). 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

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Secondary Stakeholders

Those individuals or groups with an interest in the project, including local and national government, policy makers, regulators, advocacy groups and NGOs, that are not directly impacted by the project but nonetheless have a legitimate interest in and influence over it. Source: Identifying and assessing water sources: Guidance document for the onshore oil and gas industry, International Petroleum Industry Environmental Conservation Association (IPIECA), 2014. Global Standards

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Secondary stress

Any normal or shear stress that develops as a result of material constraint. NOTE This type of stress is self-limiting, which means that local yielding can relieve the conditions that cause the stress, and single application of load will not cause failure. NOTE Definition taken from API 2RD. Source: API RP 17L2, Recommended Practice for Flexible Pipe Ancillary Equipment, First Edition, March 2013. Global Standards  

Secondary stress

Stress developed by constraint due to a geometrical discontinuity, by the use of materials of different elastic moduli under external load, by constraint due to differential thermal expansion, or by assembly load (preload) that does not impair the sealing performance of a connector. NOTE 1 Only stresses that are distributed linearly across the thickness are considered secondary stresses. For nonlinearly distributed stresses, the secondary stresses are those of the equivalent linear distribution. NOTE 2 With respect to the mechanical behaviour of the structure, the basic characteristic of secondary stresses is that they lead to plastic deformation when equalizing different local distortions in the case of excess of the yield strength. Characteristic for a secondary stress is that it is self-limiting, i.e. local flow deformation leads to a limitation of the stress. NOTE 3 Secondary stresses can be of the membrane or bending type. NOTE 4 Bending stresses caused by gross structural discontinuities and acting across the wall thickness of the pipe are classified as secondary stresses. Source: API RP 17G, Recommended Practice for Completion/Workover Risers, Second Edition, July 2006 (Reaffirmed April 2011). Global Standards  

Secondary stress

A secondary stress is any stress in the structure which is not a primary stress or peak stress. Source: API SPEC 16R, Specification for Marine Drilling Riser Couplings, Exploration and Production Department, First Edition, January 1997. Global Standards  

Secondary stress

Normal stress or a shear stress developed by the constraint of adjacent parts or by self constraint of a structure (ASME BPVC, Section VIII, Division 2, Paragraph 5.12). NOTE The basic characteristic of a secondary stress is that it is self-limiting. Local yielding and minor distortions can satisfy the conditions that cause the stress to occur and failure from one application of the stress is not to be expected. Source: API TR 1PER15K-1, Protocol for Verification and Validation of High-pressure High-temperature Equipment, First Edition, March 2013. Global Standards