Offshore Pipeline Terminology


Acid wash

Chemical treatment of steel substrate by means of diluted mineral acid (usually phosphoric acid) in combination with detergency systems.

Actuator

See Ball valve.

Added mass

Additional mass is assigned to a body to reflect the fact that the force required to accelerate a submerged body is larger than the force required to accelerate the same body in vacuum. The reason for this is that part of the surround- ing water is accelerated together with the body. The added mass is typically described by a coefficient and the mass of the volume of water displaced by the body.

Alignment sheet

Drawing showing a section of pipeline (in plan and profile), incorporating seabed features as well as physical pipeline properties and installation parameters.

Anode

Electrode from which electric current flows to an electrolyte (water, soil). On the surface an oxidation process takes place, e.g. metal to metal ions or hydroxyl ions to oxygen and water.

Anode assembly

Also referred to as anode bank. A cluster of anodes delivering current, e.g. to provide cathodic protection. Anodes placed in (onshore) soil are normally surrounded by low resistance material (e.g. coke), and are referred to as anode beds.

Anode pad

See Doubler plate. Asphalt

See Bitumen.

Asphaltene

Non-volatile, high molecular weight fraction of petroleum that is insoluble in light alkanes such as n-pentane and n-heptane.

Atterberg Limits

Limiting water contents between which soil behaviour is characterised as a plastic solid (as opposed to a semisolid or a viscous liquid).

Austenite

See Steel microstructure.

Backfilling

Covering of trenched pipeline, which may be natural (by sedimentation) or artificial (by rock dumping or by mechanically returning the seabed material removed during trenching).

Bainite

See Steel microstructure.

Ball valve

Valve where the valve body is built around a ball provided with through hole, the size of the pipe bore. The valve is closed by rotation of the ball manually or by means of a hydraulic actuator, which may be diver, ROV or remotely operated.

Barrier coating

Blockage against oxygen and other gases, as well as water and dissolved salts.

Bend

Curved piece of pipe, for offshore use either hot formed from induction bent linepipe joints (motherpipe) or forged items. Bends with small bending radius (1.5 × ID or less) are also referred to as elbows, and will normally be forged. To facilitate the welding into the pipeline, bends are normally provide with short, straight sections (tangent lengths).
























Bellmouth

Part of a guide tube, formed in the shape of a bellmouth, to control the bending curvature of the flexible pipe in dynamic or static applications.

Bending restrictor

A mechanical device that functions as a mechanical stop to limit the bending curvature of a flexible pipe in static applications.

Bending stiffener

A cone-shaped ancillary component that supports the flexible pipe and thus prevents over-bending of the pipe in dynamic or static applications.

Benthic

Generic term for plant and animal life living at the seabed.

Bitumen

Coating material derived from distillation of hydrocarbons or extracted from natural deposits (asphalt).

Bleeding

See Venting.

Bonded flexible pipe

A flexible pipe where the steel reinforcement is integrated and bonded to a vulcanised, elastomeric material.

Bottom tow

Installation method whereby pipe strings are pulled in position on the seabed (see Towing).

Buckle

Deformation of pipeline as a result of local actions or stability failure of the pipe section due to external pressure, possibly in combination with bending. The buckling may lead to water entering the pipeline (wet buckle) or not (dry buckle).

Buckle arrestor

Section of thick-walled linepipe introduced at regular intervals to prevent propa- gation buckling of a pipeline.























Caisson

Sleeve pipe housing one or several pipelines, cables, etc.

Cathode

Electrode into which electric current flows from an electrolyte (water, soil). On the surface a reduction process takes place, e.g. water to hydrogen and hydroxyl ions.

Cathodic disbonding

Loss of bond between barrier coating and steel substrate due to the formation of hydroxyl ions in connection with cathodic protection.

Cathodic protection

Electrochemical method of corrosion protection of metal structures, achieved by forcing an electric current from an anode through the surrounding electrolyte into the metal, which becomes a cathode.

Chainage

Distance measured along the pipeline by accumulating the lengths of the installed pipe joints. Owing to local deviations and seabed irregularities this will be some- what higher than the kilometre post (KP) reckoning along the theoretical pipeline route. Thus if KP numbers are used to designate chainage it should be highlighted.

Charpy V test

Test method to determine impact fracture properties of steels.

Check valve

Non-return valve, preventing counterflow. Swing check valves (also known as flapper or clapper valves) are built around a flapper disc, attached at the valve house top, which can be rotated to close the valve. During operation the disc is suspended by the fluid flow, and if there is a change in flow direction the flapper will swing closed, providing a seal that will prevent fluid loss.

Chromate conversion coating

Chemical treatment of steel substrate by wetting the surface with diluted chrom- ate acid in combination with other chemicals.

Cladding

See Sheeting.

Clapper valve

See Check valve. Crack arrestor

Device to be incorporated in a pipeline to prevent long running crack.

Coal tar

Coating material manufactured by distillation (pyrolysis) of rock coal.

Coating yard

Onshore facility for the application of pipe coatings and sacrificial anodes to pipe joints.

Cobbles

See Rock dumping.

Cold springing

Introduction of residual moment in a connection by elastic deformations during tie-in.

Collapse

Deformation of a pipeline due to a distributed load, particularly external pressure.

Components

Pressure sustaining parts of a pipeline system which are not linepipe (e.g. fittings, valves, isolation couplings, pig launchers/receivers).

Concrete coating

Pipe coating of reinforced concrete, applied to increase the pipeline weight and/ or protect the steel pipe and its anti-corrosion coating against mechanical damage.

Condensate

Liquid hydrocarbon, separated from natural gas by reduction of pressure and temperature. Also referred to as NGL.

Contractor

Executing party in a contractual relationship, including sub-contractor or supplier.

Counteract

Lateral support on the seabed, guiding the pipeline during pipelaying in hori- zontal curves, also called a turnpoint.

Corrosion allowance

Increase of the wall thickness corresponding to the expected corrosion loss, with the objective of ensuring the required wall thickness during the service life.

Crossing

Intersection of pipeline with a previously installed (operational or abandoned) pipeline or cable.

Crushing

Radial compression, which may cause a sudden collapse or significant ovalisation of the pipe cross-section.

Cutting

Trenching of pipeline by means of a mechanical digging machine riding on the pipe, towed or self-propelled.

Davit lift

Above-water tie-in operation, involving lifting of the two pipe string ends by barge-mounted cranes (davits).

Dead man anchor

High holding anchor with corresponding chain, placed on the seabed to provide tension for pipelay initiation.

Dent

Local deformation of the linepipe wall, resulting in a reduction of the pipe bore.

Design pressure

Maximum internal pressure occurring in the pipeline during normal operation, referred to a specific reference height.

Directional drilling

Installation method whereby the pre-fabricated pipe string is pulled through a hole drilled through the soil.

Dogleg

See Expansion offset.

Double jointing

Welding together of two pipe joints before they are incorporated into the pipe string.

Doubler plate

Steel plate welded on to the pipe joint under factory conditions, to provide a location for structural attachment, in particular anode pads for sacrificial anode cable connection, by stick welding, pin brazing or thermite welding.

Drop weight tear test

Test method to determine fracture properties of heavy sections of steel.

Dry buckle

See Buckle.

Duplex steel

Steel with mixed microstructure. Stainless duplex steel is a chromium alloyed mixture of austenite and ferrite. Normal grade is 22 Cr, the higher grade 25 Cr with higher strength and superior corrosion resistance is also referred to as super duplex.

Dye stick

Solid dye units designed to dissolve after flooding, and serve in case leak detec- tion is required. Dye sticks are easy to place in critical units such as tie-in or valve spools. The dye can be coloured or clear but fluorescent.

Eddie current testing

Non-destructive test method based on electromagnetic principles.

Elbow

See Bend. Elbolet

See Olet.

Enamel

Hot applied pipe coating consisting of bitumen or coal tar, reinforced with layers of fibreglass wrap.

Epoxy paint

Two-component paint consisting of epoxy resin and solvent.

Expansion buckling

Lateral deformation, possibly of large displacement, of a pipeline, caused by prevented longitudinal expansion to relieve compressive forces due to increases in pressure and/or temperature.

Expansion offset

Pipe spool (in the shape of an L, Z or U) that is inserted between a pipeline and a fixed structure (e.g. a platform riser or a wellhead) to absorb longitudinal deformations due to changes in temperature or pressure of the pipeline medium. Also referred to as an expansion loop or dogleg.

Export pipeline

Pipeline transporting a treated product (gas, condensate, oil) from an offshore facility. It may be an interfield pipeline or a transmission pipeline.

Fall pipe

Vertical steel pipe suspended from a surface vessel, through which rock or gravel is dumped on the seabed. See Rock dumping.

Ferrite

See Steel microstructure.

Field joint

Connection of two pipe joints carried out on site (offshore or at an onshore site or construction yard). It includes the girth weld and the field joint coating, bridging the gap between the factory-applied anti-corrosion coating on the out- side, and possibly also the inside, of the pipe. Additional field joint infill may fill the gap between insulation or concrete coating on the adjoining pipe joints.

Firing line

Work area on a laybarge where the pipe joints are welded onto the pipe string.

Fish

Streamlined platform or container for survey, and other, instruments; towed by a surface vessel along a specified route, used for data gathering.

Fittings

Pipeline components that do not have operational functions (e.g. flanges, tees, wyes, olets).

Flapper valve

See Check valve. Flange connection

See Mechanical connection.

Flexible pipe

Factory produced pipe string characterised by a layered configuration, resulting in a bending stiffness which is orders of magnitude smaller than for steel pipe of similar dimension.

Flooding

Filling the pipeline with water, to perform hydrotesting or to facilitate tie-in.

Flotation

Upwards directed, vertical instability of a buried pipeline.

Flow assurance

The prevention of production losses by ensuring unrestricted flow path in the pipe transportation system during its service life.

Flowline

Pipeline transporting untreated well fluids.

Flow regime

Nature of the transported medium. Normal designations are: single phase (liquid or gaseous), two-phase (e.g. oil and gas) and multi-phase (e.g. oil, gas, water and particles).

Fracture toughness

Measure of the ability to resist crack propagation under sustained load. See also Impact toughness.

Free span

Section of pipeline unsupported by the seabed.

Girth weld

Circumferential weld between pipe joints. See also Field joint.

Gouge

Local linepipe imperfection, affecting the pipe wall only, without resulting in a reduction of the pipe bore.

Gravel

See Rock dumping.

Heat affected zone

Zones adjacent to welds where the heat input from welding changes the base metal microstructure.

Heat shrink sleeve

Field joint anti-corrosion coating consisting of cross-linked polyolefin, which shrinks upon the application of heat.

Hot spot stress

Imaginary reference stress for welded joints. Hot spot stress is established by extrapolation of stresses outside the weld notch zone into the singularity at the

weld root or toe. Hot spot stress includes geometric stress concentration, but not the high local stress generated by the welding process.

Hot-tapping

Connection of a branch line to an existing pipeline without emptying the latter, as an alternative to using a pre-installed tee (or wye).

Hub

Short piece of pipe with a raised flange to engage with a remotely operated tool (e.g. for tie-in or hot-tapping).

Hydrates

Ice-like combinations of water and natural gas, formed for certain temperature and pressure conditions, depending on the gas composition.

Hydrogen embrittlement

Damage to steel material incurred through the uptake of atomic hydrogen, e.g. in connection with welding, galvanising, cathodic protection or corrosion.

Hydrotesting

Short for hydrostatic testing, whereby the strength and tightness of a pipeline section is documented by flooding with water and pressurising.

Hyperbaric welding

Welding performed subsea in a pressurised habitat. See also Saturation diving.

Impact toughness

Measure of the ability to resist crack initiation and propagation under high impact loads. See also Fracture toughness.

Impingement

Application of concrete coating whereby a no-slump concrete mix is thrown at the rotating pipe joint.

Impressed current

Method of cathodic protection where the driving current is delivered from an external power source.

Incidental pressure

Maximum internal pressure that can occur in the pipeline during operation, referred to the same reference height as the design pressure.

Infill

Field joint coating material filling the gap between the coatings on the adjacent pipe joints.

Inhibitor

Substance added to a transported medium to reduce corrosion.

Initiation head

See Laydown head.

Intelligent pig

Pig equipped with sensors and recording devices used for internal inspection of pipelines.

Interfield pipeline

Pipeline between offshore structures or installations.

Isolation coupling

Pressure sustaining device providing electrical isolation of two pipeline sections.

Jetting

See Water-jetting.

J-laying

Pipelaying where the pipe string leaves the laybarge in a vertical or nearly vertical position.

J-tube

A pre-installed vertical, or near vertical, protection tube having a straight section with a bend at the lower end, through which a riser may be pulled. If the bend is omitted the term I-tube is used.

Jumper

Short flexible pipe used subsea and topside in static or dynamic applications.

Landfall

See Shore approach. Landline

Onshore pipeline.

Latrolet

See Olet.

Laybarge

Vessel (whether self-propelled or not) used for pipelaying.

Laydown head

Piece of pipe with a wire attachment, welded on to the end of a pipe string to facilitate later retrieval. The laydown head at the start of pipelaying is called an initiation head, and may be provided with valves and pigs for dewatering of the line. To provide tension for pipelaying the initiation head is attached to a dead man anchor or to start piles. For a towed or pulled pipe string the term pull head is used.

Linepipe

Steel material for welded pipelines.

Lining

See Sheeting.

Liquefaction

Soil state where the effective stresses between the grains vanish, causing the soil to behave like a fluid.

Location Class

DNV classification of pipelines based on failure consequences due to location. Location Class 2 are areas (near platforms or landfalls) with frequent human activity, Location Class 1 is everywhere else. Also referred to as Zone 2, respect- ively Zone 1.

Magnetic particle inspection

Non-destructive test method based on magnetic fields around surface discontinuities.

Marine pipeline

Pipeline crossing a body of water (normally salt, but also fresh).

Martensite

See Steel microstructure.

Maximum wave height

Maximum height of waves in a sea state, measured as the vertical distances between succeeding wave troughs and wave crests.

Mechanical connection

Means of connecting pipes (tie-in) without welding, normally made by the bolt- ing together of flanges welded to the two pipe strings. May involve proprietary coupling devices and tie-in tools.

Medium

Substance (gas, liquid, slurry) being transported through a pipeline. See Flow regime.

Meteo-marine

Meteorological and hydrographical (data or investigations). Also referred to as metocean.

Mill test pressure

Internal test pressure applied to linepipe joints during manufacture.

Miner’s rule

See Palmgren–Miner’s rule Moonpool

Access to the sea (e.g. for divers) located inside a vessel.

Motherpipe

See Bend. Non-return valve

See Check valve.

Normalising

Heat treatment of steels aimed at improving the final microstructure and increas- ing the mechanical properties.

Olet

Collar-shaped fitting welded on to the pipeline to reinforce a small bore branch connection. The connection may be welded (weldolet) or threaded (thredolet). Normally the branch is perpendicular to a straight pipe run, but it may be oblique (latrolet) or placed on a bend (elbolet).

Operating pressure

Internal pressure at which the pipeline is normally operated.

Ovalisation

Difference from a circle of the pipe cross-sectional geometry, usually arising from the fabrication process or as a result of bending. The ovality may be measured in percentage terms or as the difference between maximum and min- imum diameters. Also referred to as out-of-roundness.

Overbend

Curved section of the pipe string supported by the laybarge stinger during S-laying.

Owner

Receiving party in a contractual relationship, pipeline operator.

Palmgren–Miner’s rule

Method for predicting fatigue life under any type of variable amplitude loading. The method is based on a linear accumulation of the damage induced by each stress cycle.

Pearlite

See Steel microstructure.

Pig launcher/receiver

Facilities connected to a pipeline (separated by valves) for the dispatch and collection of pigs. Also referred to as pig traps.

Pig train

Series of different purpose pigs, separated by slugs of liquid.

Pigging

Passage of a pipeline by spherical or cylindrical devices (pigs), propelled by the transported medium. Pigs are used for cleaning, gauging, internal inspection (see Intelligent pig), or the separation of different transported media. Pigs can be uni-directional or bi-directional, the latter implying that the pig can be propelled from either end. Similarly, bi-directional pigging means pigging of the pipeline in both directions.

Piggy-backing

Installation method whereby a (smaller) pipeline is attached to another (larger) pipeline by strapping or clamping during pipelaying.

Pin brazing

Electrical cable connection made by brass soldering of a pin through a hole in the cable shoe.

Pipe jacking

Tunnelling method for installing underground pipelines with a minimum of sur- face disruption. The pipes are assembled at the foot of a shaft and jacked through the ground while the soil is removed from inside the encasement.

Pipe joint

Unit of linepipe manufactured at a pipe mill. For offshore application the length is normally 12.2 m (40′).

Pipe Mill

Production facility for pipe making.

Pipe string

Section of a pipeline welded together from pipe joints or manufactured as a flexible pipe. Also referred to as a stalk.

Pipe-in-pipe

Thermal insulation concept where insulation material is introduced in the annulus between the product pipe and a rigid sleeve pipe.

Pipelaying

Installation method whereby the pipe string is welded together on a laybarge as it is installed on the seabed.

Pipeline

Tubular conduit made from linepipe or flexible pipe transporting a medium, the driving force being a pressure differential between inlet and outlet.

Pipeline bundle

Several pipelines (and possibly cables) enclosed in a common caisson or sleeve pipe.

Pipeline system

Complete pipeline from inlet to outlet, including any risers, expansion offsets, valve assemblies, isolation couplings, spur lines, shore approaches, pig launchers/ receivers, etc.

Pitting

Localised corrosion attack.

Ploughing

Trenching of pipeline below the seabed by means of a plough riding on the pipe, normally towed. The plough may be used for backfilling as well, either simultan- eously or consecutively.

Pour-point depressant

Additive for lowering the temperature at which the oil will pour or flow when being chilled.

Pre-commissioning

Activities (e.g. cleaning, de-watering, drying) which are required before a pipe- line can be taken into operation (commissioned). Also referred to as RFO.

Pressure control system

System for controlling the internal pressure in the pipeline, comprising the pres- sure regulating system, the pressure safety system, and associated monitoring and alarm systems.

Pressure regulating system

System for ensuring that a set internal pressure in the pipeline is maintained.

Pressure safety system

System, independent of the pressure regulating system, for ensuring that the internal pressure in the pipeline does not exceed the allowable incidental pressure.

Pressure surge

Increase in pipeline pressure following a flow incident. A sudden valve closure or a decreasing pump outlet will result in a pressure surge.

Propagating buckle

Collapse of a large section of a pipeline (propagation buckling), due to external pressure following local buckling (see Buckle).

Propagating fracture

Fracture that runs apace for a significant length.

Pull head

See Laydown head.

Pup piece

Short spool piece welded onto component (e.g. valve or tee piece) to provide transition to the topical linepipe (diameter, wall thickness and steel quality).

Reeling

Installation method whereby the pre-fabricated pipe string, spooled on to a drum or reel, is paid out by a reel barge.

Ribbon anode

Long, thin sacrificial anode placed adjacent to the pipeline (in the soil or inside a caisson) to provide cathodic protection.

Ripple factor

Intensity of small fluctuating loads superimposed on (high) nominal (mechanical or current) loads.

Riser

Pipe string connecting an above-water offshore facility with a pipeline on the seabed. The tie-in to the pipeline (or expansion offset) may be direct or through an intermediate structure (riser base) on the seabed.

Riser guard

Steel structures, welded or bolted to the platform at the water line to protect risers against impact from vessels or floating debris.

Rock dumping

Placement of rock material on the seabed, e.g. as scour protection, support of a pipeline at a free span or crossing, or covering of a pipeline (trenched or untrenched) for protection or control of expansion or upheaval buckling. Rocks of sizes between 60 mm and 200 mm are called cobbles, whereas lower dimen- sions are referred to as gravel. The gravel fraction is further divided into coarse (20–60 mm), medium (6–20 mm) and fine (2–6 mm).

Sacrificial anode

An anode which connected to a structure can offer cathodic protection while it is consumed.

Safety Class

Classification of pipelines based upon the risk of human injury, environmental damage and economic loss. Pipelines are classified according to category of transported medium, location class, and duration of exposure (temporary or operational phase).

Sagbend

Curved section of the pipe string supported by the seabed during S-laying.

Saturation diving

Diving under (nearly) constant pressure, the diver alternating between working subsea, normally in a pressurised habitat, and living in a pressure chamber envir- onment, obviating the need for depressurisation at the completion of each dive.

Scale formation

Forming of reaction products or settling of foreign matter on to surfaces.

Self-burial

Naturally occurring penetration into the seabed due to wave and current action.

Service line

Pipeline (normally small diameter) transporting an auxiliary medium (e.g. methanol or lift gas).

Sheeting

Sandwich combination of a carbon steel plate with a plate of corrosion resistant alloy. The process is referred to as cladding if there is metallic bond between the two layers. A CRA lining (typically inside a pipe) may or may not be metallically bonded to the carbon steel.

Shore approach

Connection between a marine pipeline and a landline, also referred to as a landfall.

Significant wave height

Statistical parameter characterising a sea state. The significant wave height was originally defined as the average wave height of the highest one third of the waves in a wave record. The significant wave height, Hs, is today in most cases calculated using the statistical parameters of the spectrum characterising the sea state (Hs = 4m0 , where m0 is the zero moment of the wave spectrum).

S-laying

Pipelaying where the pipe string leaves the laybarge in a horizontal or nearly horizontal position (as opposed to J-laying).

Sleeve pipe

See Caisson. Slug catcher

Facility for separating and receiving liquid dropout in gas pipelines.

Slug flow

Intermittent gas and liquid flow regime in a pipeline or riser during operation.

Slurry

Transported medium consisting of solid particles suspended in a liquid.

Snaking

Horizontal, or nearly horizontal, expansion buckling, the pipeline sliding on the seabed.

Sour service

Operation of pipes or equipment in wet environments containing hydrogen sulph- ide, giving rise to sour corrosion.

Spool piece

Segment of pipe (including straight sections and/or bends) fitted between a pipe string and a fixed structure or component (e.g. riser, wellhead, valve assembly, pig launcher/receiver). See also Pup piece.

Spur line

Branch pipeline connected to the main pipeline by a tee or a wye.

Stalking

Installation of a riser already connected to a pipeline on to an offshore platform. See also Pipe string.

Start piles

Temporary structure on the seabed, installed by a subsea pile hammer or by the use of suction piles, to provide tension for pipelay initiation.

Steel microstructure

Grain structure of steel resulting from the manufacturing process. Typical micro- structure designations are: austenite, martensite, ferrite, bainite and pearlite.

Stinger

Structure extending from the laybarge stern supporting the pipe string during S-laying.

Subsea

Generic term describing equipment or processes on the seabed.

Subsea completion

Hydrocarbon production unit (wellhead) located subsea.

Submerged weight

Weight in water, i.e. weight in air reduced by the buoyancy of the seawater.

Suction pile

Anchorage on the seabed provided by a cylinder, closed at the top and open at the bottom, which is evacuated to create an under-pressure.

Swan neck

S-shaped double bend, typically forming the vertical transition between a pipe- line on the seabed and a raised component or structure.

Sweet service

Operation of pipes or equipment in wet environments containing carbon dioxide, giving rise to sweet corrosion.

Tangent length

See Bend.

Tee piece

Fitting for connection of a spur line perpendicularly to the main pipeline, usually permitting pigging of the main line, but not the spur line. Normally the complete tee will be provided with elbow, valve, flange, etc. Alternatively, the tee piece may be provided with a hub for connection of hot-tapping tool.

Tensioner

Device on a laybarge gripping the pipe string (by caterpillar tracks or similar) to keep it under tension during pipelaying.

Thredolet

See Olet.

Thermite welding

Electrical cable connection made by ignition of exothermic metal powder in a mould enclosing the cable end.

Tie-in

On-site connection of pipe strings to each other, to risers, to subsea completions, or to adjoining landlines.

T opside

Generic term describing equipment or processes above water on offshore facilities.

T owing

Installation method whereby pre-fabricated pipe strings or bundles are towed into position on the seabed.

Transition temperature

A specific temperature where the steel impact properties change from ductile to brittle behaviour.

Transmission pipeline

Pipeline (normally large diameter) transporting a treated medium (e.g. crude oil or sales gas), usually over long distances. Also referred to as a trunkline.

Trenching

Positioning of a pipeline below seabed level, with or without backfilling.

Trunkline

See Transmission pipeline. Turnpoint

See Counteract.

Twin anodes

Two sacrificial anodes mounted adjacent to one another on the pipeline and functioning as one anode.

Umbilical

A bundle of helically or sinusoidally wound, small diameter chemical, hydraulic, and electrical conductors for power and control systems.

Unbonded flexible pipe

A flexible pipe consisting of separate polymeric and metallic layers, where the layers are allowed to move relative to each other.

Upheaval buckling

Vertical expansion buckling of a pipeline, normally through the soil cover.

Usage factor

Ratio between actual and allowable value of a given parameter, normally stress. Also referred to as utilisation ratio.

Valve assembly

One or more in-line valves (e.g. ball valve, check valve, SSIV), including any by-pass lines and supporting/protective structures.

V enting

Intentional release of pipeline content to the environment, usually through a valve. In the case of liquid media the term bleeding is used.

Water-jetting

Trenching of pipeline by means of pressurised water, delivered from a towed trench machine riding on the pipe. On a small scale compressed air (air-jetting) may also be used.

Waterstop

Inflatable bladder deployed in the flooded pipeline to seal the end during tie-in operations in a dry habitat. It may also seal a dry pipeline against flooding when the laydown head is removed (e.g. for tie-in).

Weight coating

See Concrete coating. Weldolet

See Olet. Weld-overlay

Build-up of surface layer by a welding process.

Wellhead

See Subsea completion.

Wet buckle

See Buckle.

Wet welding

Welding under water (or in wet environment) without the use of a dry habitat. See also Hyperbaric welding.

Wye piece

Fitting for connection of a spur line obliquely to the main pipeline, normally permitting uni-directional pigging of the main line, or both lines if the bores are not (too) different.

 

Offshore Pipeline Terminology (A to Z)

Oil & Gas Production SitemapOil-and-Gas-Production-Foundation.htmlshapeimage_2_link_0
Drilling Sitemaphttp://www.sereneenergy.org/shapeimage_3_link_0

  1. Oil and Gas Production

  2. Production Technology Foundation

  3. Company Operations contribution

  4. Timescale of Involvement of PT

  5. Topics within Production

  6. Well Completion

  7. Well Stimulation

  8. Associated Production Problems

  9. Remedial and Workover Techniques

  10. Oil & Gas Production System

  11. Group Gathering Station

  12. Gas Compression Plant

  13. Gas Collection station

  14. Crude Tank farm

  15. Effluent Treatment Plant

  16. Central Water Injection Plant

  17. Oil & Gas Production Introduction

  18. Crude Oil and Natural Gas

  19. Petroleum Industry History

  20. Oil & Gas Production Overview

  21. Oil & Gas Production Facilities

  22. Overview of Wellhead

  23. Manifold, gathering and separation

  24. Separation of Oil and Gas

  25. Metering, storage and export

  26. Gas Treatment and Compression

  27. Gas Properties

  28. Mass and Weight

  29. Volume

  30. Density, Specific Weight and Specific Volume

  31. Viscosity

  32. Ideal Gases

  33. Real Gases

  34. Heating Value

  35. Formation Damage

  36. Radial Flow and Formation Damage

  37. Radial flow

  38. Near Wellbore Flow Restrictions

  39. Potential Formation Damage Mechanisms

  40. Causes and Effects of Sand Production

  41. Nature of Sand Production

  42. Effects of Sand Production

  43. Causes of Sand Production

  44. Predicting Sand Production

  45. Operational and Economic Influences

  46. Formation Strength Log

  47. Sonic Log

  48. Formation Property Log

  49. Porosity

  50. Drawdown

  51. Finite Element Analysis

  52. Time Dependence

  53. Multiphase Flow

  54. Sand Control Techniques

  55. Maintenance and Workover

  56. Rate Exclusion

  57. Plastic Consolidation

  58. High Energy Resin Placement

  59. Resin Coated Gravel

  60. Slotted Liners or Screens without Gravel Packing

  61. Slotted Liners or Screens with Gravel Packing

  62. Gravel Pack Sand Design

  63. Formation Sand Sampling

  64. Sieve Analysis

  65. Gravel Pack Sand Sizing

  66. Gravel Pack Sand

  67. Gravel Pack Sand Substitutes

  68. Slotted Liner and Wire Wrapped Liners

  69. Slotted Liner and Wire Wrapped Liners

  70. Slotted Liners

  71. Wire Wrapped Screens

  72. Prepacked Screens

  73. Flow Capacities of Screens and Slotted Liners

  74. The Excluder

  75. Erosion Test for Sand Control

  76. Gravel Pack Completion Equipment and Service Tools

  77. Sump Packer

  78. Seal Assemble for Gravel Pack

  79. Gravel Pack Screen ; Blank Pipe

  80. Shear Out Safety Joint and Knock out Isolation Valve

  81. Gravel Pack Extension Packer

  82. Gravel Pack Service Tool

  83. Open Hole Gravel Pack Completion Equipment

  84. Well Preparation for Gravel Packing

  85. Drilling Practices

  86. Cleaning the Casing Open Hole Work String ; Surface Facilities

  87. Filtration for Gravel Packing

  88. Completion/Gravel Pack Fluids

  89. Open Hole Gravel Packing

  90. Guidelines for Selecting Open Hole Gravel Pack Candidates

  91. Top Set Open Hole Gravel Pack

  92. Gravel Pack Equipment and Gravel Placement

  93. Set Thru Open Hole Gravel Pack

  94. Oil and Gas Pipeline

  95. Design of Marine Pipeline

  96. Pipeline Installation Introduction

  97. Offshore Pipeline Functional Req.

  98. Offshore Pipeline Authorities’ Req.

  99. Environmental Impact

  100. Pipeline Operational Parameters

  101. Pipeline Size Determination

  102. Flow Simulation in Pipeline

  103. Geophysical Pipeline Site

  104. Investigation Survey

  105. Geotechnical Pipeline Site

  106. Investigation Survey

  107. Soil Sampling & In-Situ testing

  108. Wind, Waves and Current

  109. Collection of Wave Data

  110. Linepipe Materials

  111. Strength, toughness, Weldability

  112. Steel Microstructure

  113. Oil & Gas Terminology

  114. A    B    C    D    E    F    G    H    I    J    K    L    M    N    O    P    Q    R    S    T    U    V    W    X    Y    Z  

  115. Offshore Pipeline Terminology

  116. Petroleum Videos

  117. Peak Oil Video

  118. Oil and Gas Economics

  119. Ghana Oil and Gas Production

  120. Oil and Gas Well Drilling

  121. Well Completion

  122. Artificial Lift Techniques