Glossary of Terms

5/10/2018 Glossary of Terms - slidepdf.com

http://slidepdf.com/reader/full/glossary-of-terms-559dfc594c54f 1/14

PITAC Ltd.: Professor J M Peden Completions and Workovers/ Introduction to Production Technology

PRODUCTION OPERATIONSGLOSSARY OF TERMS

A-Z TERM EXPLANATIONA Annulus Refer ‘Annular Pressure’

A P I American Petroleum Institute, which sets standards of quality andprocedures for all field equipment and practices.

Acid Frac The injection of acid into reservoir at a pressure, which exceeds theinjection pressure into the formation. The migration of the acid into thereservoir is via a fracture.

Acidise To inject acid into the reservoir to improve the conductivity of the rock

either by dissolution of the matrix, or alternatively, dissolution of thematerial, which was plugging the reservoir pore space.

Actuate To operate or initiate the operation of a device

Alloy An alloy is a steel whose properties are modified by the addition of alloying elements, which typically are metals, which will enhancecorrosion properties, strength or workability of a steel.

Annular Pressure

The residual pressure remaining in the wellhead within the annulusbetween casing strings or between a casing and tubing at surface.

Annular Preventer

The annular preventer is a device, which can close off the annular space around a tubing string, or wire inside a well. This provides abasic form of well closure and the ability to control reservoir pressure.

Asphaltene

B B O P The Blow-out Preventer is used in drilling and well interventionoperations, such as wireline, coiled tubing and snubbing. It consists of a number of devices which allow isolation of the well cross sectionalarea at surface. The system normally consists of an annular preventer

and a series of rams, which are designed to close off around pipe or wireline which is suspended through the B O P inside the well.

Barefoot A Barefoot completion is one in which a drilled hole is completed withall of the section open and available to contribute production into thewell.

Barrier The Barrier Policy refers to a number of means of restriction or preventing flow occurring to surface during a range of well operationssuch as drilling, completion and intervention. Normal requirements arefor a number of barriers to exist in the flow path from the reservoir tothe flowline at surface. These barriers could be mechanical, or

hydraulic in the form of a fluid column which exerts a hydrostaticpressure greater than the reservoir pressure at the base of the well.

GLOSSARY OF TERMS/Pitac Ltd Page 1




Beta Ratio The Beta Ratio is a measure of the extent to which particles areremoved from a liquid system. The ratio defines the percentage of particles removed to the percentage concentration of particles in place.

Bonded Seal A Bonded Seal is a seal ring which achieves sealing within a seal bore

because of its outside diameter being fractionally larger than the I.D. of the sealed bore. It is similar to an O ring seal and is mounted on a sloton a seal stack.

Box The Box refers to the female threaded coupling section.

Braided Cable A Braided Cable is a multi strand spirally wound cable used for wirelineoperations. In some cases, it has a copper core and acts as a signalconductor to surface.

Bridge Plug A Bridge Plug is an isolation packer which can be run down through

casing, or in some cases, through tubing, and when set provideseffective hydraulic and mechanical isolation of a tubular system. TheBridge Plug is principally run down on wireline or on coiled tubing.

Bridging Bridging refers to the physical process by which particulates willcollectively bridge or seal pore throats, thus restricting fluid inflowthrough the borehole wall.

Bump This term refers to a pressure signal which is achieved when a cementplug is landed in place and indicates a position of the cement columnduring primary cementing of a casing.

Burst Burst refers to the failure load condition on a tubular where the externalpressure exceeds the internal pressure and leads to rupturing of thetubular system.

C C.C.L.Casing ColumnLocator

This electromagnetic tool created a magnetic field which is a function of the tubular wall thickness, and is therefore used to identify the locationof casing or tubing couplings for depth control.

C.E.T.CementEvaluation Tool(Schlumberger)

This is an acoustic tool which measures the compressive strength of materials in annuli outside casing

Cap (Tree) Tree Cap is placed on top of a Xmas tree to effectively seal off the top.

CapacitanceTool

A Capacitance Tool is a production logging tool which measures theelectrical conductivity of capacitance of fluid. As such, it can be used tomeasure the density of fluids, and in particular water cut even in wellsat high angles.

Carbon Steel Carbon steel is manufactured by combining carbon and steel andheating them to high temperatures where the mixture becomes molten

and diffuses.





Check Valve A Check Valve is a valve designed to eliminate flow in a specificdirection. It could be used as either a one-way check valve or a twoway system.

Chevron Seal This is an angled seal unit manufactured from a pliable material which

can provide extension to a seal bore wall under the application of adifferential pressure.

Choke Choke refers to the process of throttling flow and creating backpressure. This operation is conducted at surface and in some cases isadditionally installed subsurface.

Clay Clay is a mineral often found in the majority of clastic reservoirs andcomprises a mixture of sodium, aluminium and other mineralhydroxides.

Clean-up This is the process of bringing a well into production following acompletion or workover and refers to establishing steady-state flowconditions and removal of any new wellbore damage or invasioneffects.

Coiled Tubing Coiled Tubing is a continuous reel of tubing which is used for a range of intervention and production operations. The tubing is available in sizesof less than 1" to approx.7" diameter.

Collapse Collapse is a tubing failure mode where the tubing wall is unable towithstand a high differential pressure course applied across the wall,

caused by a higher external, compared to internal, pressure.

Collet A Collet is a small lock ring or latch which can be engaged tophysically/ mechanically lock two pieces of equipment together.

Concentric(w/o)

This refers to Concentric Workover unit which is a tubular systemdesigned to be run down the inside of production tubing or casing. Itsmain function is to allow concentric access for workover operationswithout the need to remove the production tubing.

Conslot This is a proprietary screen to provide sand control and is based upon amechanical slot configuration to provide bridging of sand grains.

D Damage Damage is impairment created to the productivity or injectivity of a well.It typically results in a reduction in the fluid mobility in the near wellboreregion.

Dissolver Dissolvers such as scale dissolvers are chemical fluids used to removesolid precipitates of particles.

Dope This is a grease applied to a tubular coupling (A.P.I couplings) and isdesigned to seal off the channel through the thread section

hydraulically.





Dry Tree This is a subsea tree system, whereby the Xmas tree is installed withina hyperbaric or one atmosphere chamber on the seabed. Access to thetree for repair work is achieved by re-entry to the chamber.

Dummy This is a small sleeve, normally installed in hole control devices such as

subsurface safety valves or site pocket mandrels during completionoperations. Its function is to protect the seal bore surface, and will bereplaced by the control valve at a later stage.

E Elastomer An elastomer is a long chain hydrocarbon molecule which ispolymerised.

Emulsion Emulsion is a dispersal of two fluids which are immiscible. The highsurface tension creates rigidity in the disperse phase and gives rise tohigh viscosity.

Engage This is the process of one tool system entering the appropriate profile inanother device.

Excluda Screens(Baker Oil Tools)

These are premium sand control screens, which consist of a series of layers of wire mesh that will provide bridging and removal of sandparticles from the flow screen.

Expandable Expandable screens and liners refer to tubular systems that can be rundownhole and their effective O.D. can be increased by the defamationsubsurface using a polymer or pressure.

F F Nipple A Baker F Nipple is a positive isolation nipple, normally deployed at thebase of the tubing string in the tailpipe and is used to accept monitoringor isolation equipment.

F.B.H.P Flowing bottomhole pressure

Fish Fish refers to an object which has been accidentally lost or dropped intoa well during drilling, production or workover phases. The Fish couldeither be pipe, a tool or wire.

Flange Flange is a circular face which can be used to bolt or clamp equipmenttogether. In most oilfield applications, flanges such as those onwellheads and Xmas trees will have a circular seal ring placed betweenthe flange faces which will be compressed.

Flow meter Flow meter measures the volumetric flow rate. In production andinjection wells flow meters are run into the well on either a continuousor a static basis and measure the volumetric flow rate by linking therotational speed of a spinner using an electrical current, generated byelectromagnets.

Fluid cushion The Fluid cushion refers to the hydraulic placement of a column of

lightweight fluid placed within production tubing from surface to aspecific depth to reduce the bottomhole pressure at the base of the





well. This is necessary to allow the well to flow in either a production or test situation.

Flux Rate This refers to the volumetric or mass flow rate of fluid which enters aborehole, typically through the borehole wall at the base of the well.

Frac A well is fractured or ‘fracced’ when the pore pressure within the rock isincreased to a level which exceeds the sum of both the minimum stressand tensile strength of the formation. The well fractures or cracks opendue to this hydraulic pressure. Since the rock is elastic, the fracture willclose unless it is filled or propped with a material, or the fracture face isacidised.

Frac pack A Frac Pack is a short or limited depth of fracture which is created andis then packed with a proppant or resin coated sand. The objective of the Frac pack is to promote flow in the near-wellbore region with less

pressure drop and thus alleviate inertial stresses created by the fluidflow through the formation.

FTHP Flowing tubing head pressure

G Gamma Ray A Gamma ray tool measures the natural radioactivity of a formationwhich is indicative of the clay or shale content of the formation. Thetool is used as an indicator of cleanliness of the sandstone, but is alsoused for depth correlation.

Gooseneck A Gooseneck is a radius arm which is used in coiled tubing operations,

to allow the coiled tubing to be bent from horizontal to vertical to allowits injection and retrieval from the well.

Gradio-manometer

Gardiomanometer is a production logging tool which measures thehydrostatic head over a 2-3 ft spacing and as such allows the density of the fluid at that depth to be interpreted.

Grapple A Grapple is a fishing tool which is designed to engage around the neckof devices which are run, typically, on wireline or coiled tubing.

Gravel Pack A Gravel Pack refers to a sand control completion in which a wirewrapscreen is placed within an open or cased hole and a gravel is circulatedinto the annulus between them. The wirewrap screen is designed toretain the gravel and the gravel offers a pore throat size which willrestrict the movement of the production sand.

H H-Member An H-member is a tubular coupling which offers an ‘H’ configurationand is used in completions such as those for T.F.L., thus allowing Utubing between one string and another.

I Injector head The injector head on a coiled tubing system provides the thrust and pull

capacity to both inject and retrieve coiled tubing from the well. Ittypically consists of a series of chains with gripper blocks.





Inhibitor An Inhibitor is intended to restrict or impair the deposition of precipitating material such as scales, wax, asphaltene or to reduce or prevent acidic corrosion inside wells.

J

K Kill Operations ‘Kill’ refers to an operation conducted to re-establish a hydrostaticoverbalance of the pressure in a borehole above that in the reservoir pore pressure. It is part of a barrier policy which will be required duringworkovers.

Kill Weight Kill weight refers to the weight of a fluid required to effect hydraulicoverbalance.

L Land off (out) This refers to the process of positioning tubulars or hangers inside thewell and the transference of some of all of the suspended weight.

Liner A Liner typically refers to a short section of casing which is run across ahole section, but terminates inside the shoe of the previous casing.There is a degree of overlap between the top of the liner and thebottom of the previous casing.

Liner Lab This refers to the length of liner which exists above the base of thecasing and is typically of the order of 500-1000 ft.

Locomotive

Unit

This refers to the rubber veined pressure seals which are used through

flow line operations as a piston unit to harness the hydraulic pressureand cause the tool string to be pushed down or retrieved from the well.

Lubricant(Thread)

A Thread Lubricant is designed to ease make-up for the tubular connection and to allow maximum make-up to the requiredengagement without excessive torque.

Lubricator A Lubricator is a length of high pressure joints which are screwedtogether and assembled above the wellhead or Xmas tree to allowwireline or coiled tubing operations to be conducted with a live well, i.e.tubing head pressure on the well. The Lubricator can be disconnectedfrom the wellhead to allow the tool to be inserted and positioned abovethe well, prior to its being run concentrically down the inside.

M M.A.A.S.P Maximum Allowable Annular Surface Pressure

M.A.T.H.P Maximum Allowable Tubing Head Pressure

M.T.T.F. Mean Time To Failure – This defines the time required prior tomechanical failure of a component.

Mandrel A Mandrel (lock Mandrel) is a tubular device which is run down

concentrically within a production tubing and is designed to bothmechanically engage and seal within the bore of a nipple profile. Its





purpose is to allow the transportation and suspension of a flow controldevice in the well.

Manifold Collection of pipes which are brought together and joined to allow co-mingling of fluids or their distribution.

Mill-outExtension

In permanent packer applications, it is necessary to mill-out the sectionof the packer which holds the top set of slips in place prior to itsretrieval. The Mill-out extension is a small sub placed underneath thepermanent packer, as part of the tailpipe, and allows engagement of the catch sleeve with a packer milling tool, such that the packer can bemilled and retrieved in one trip.

Mineral Acid A Mineral Acid is a high strength acid such as hydrochloric or hydrofluoric acid, used in well acidisation. The mineral acid refers tothe halogen element, which is part of the acidic system.

N Nipple A nipple is a small section of a tubular joint which is threaded to bothends and is made up as an integral part of the tubing string during therunning of the completion. The nipple offers an internal recess withinits bore and a seal bore beneath it. Nipples are installed at strategicpoints in the production tubing and are designed to accept theinstallation of a flow control device using a mandrel.

No Go ‘No Go’ refers to a shoulder, typically within a nipple profile, whichoffers a minimum bore restriction within that profile, and thus allowsland-out of lock mandrels within the profile.

Normalise Normalise refers to the process of allowing steel to cool from its moltenstate to ambient conditions without force convection or quenching.

O Ovality Ovality defines the extent to which a circular tube has an oval cross-section, and is particularly relevant to tubing such as coil tubing, whichis wound on a drum.

Overbalance Overbalance refers to the condition in which the bottomhole hydrostaticpressure exceeds the pressure in the formation at that depth.

Overpull Overpull refers to the amount of tensile load which is required or applied in excess of the design figure.

Overshot An overshot is a fishing tool which has an internal grapple or spiralwithin its section and is run over the top of a ‘fish’ and upon puttingtension, engages and retrieves the fish.

P Pack off A Pack off is a seal which is usually placed or injected around the neckof a tubular component.

Packer Packer is a completion component which is used to provide isolation of the annulus between the tubing and the casing or liner. In some cases,





the packer can be set in openhole conditions.

Packer Fluid A Packer Fluid fills the annulus between the tubing and the casing in aproduction or injection well, and is placed above the packer.

Perforate Perforating is required to provide hydraulic communication between thewellbore and the reservoir in situations where a liner or casing hasbeen run, cemented and thus isolates the formations within thereservoir from the borehole.

PerforatedTube

A Perforated Tube is a section of tubing which is normally pre-drilled atsurface and offers fluid access into the tubing through, for example, thetailpipe.

PermanentPacker

A Permanent packer is designed such that it cannot be retrieved bysimply reversing the setting process. The design typically involves an

opposing set of slips and as such, locks the packer in place and allowsit to withstand high differential pressures and forces form either aboveor below.

Pick Up This normally defines the amount of weight or tensile load which ispulled on a string during running or retrieval operations.

Plastic A Plastic is a dense, elastomeric material which provides seal integrity.The material is not pliable, but can be deformed under high loadconditions.

Plug Plug refers to an end cap placed across a lock mandrel which is run

down and installed inside a nipple profile.

Power Swivel

Premium Seal

PremiumThread

A Premium Thread is a threaded coupling on a tubing system which isdesigned to provide high pressure sealing, particularly for gas wells. APremium thread provides a full circumventional seal in the threadsection, either by having a metal to metal face or some form of elastomeric seal ring.

Production Log Production Log is a logging tool or tools which are run into a well whichis on production or injection, and is used as a diagnostic system. Thelog can either be run in an open or cased hole.

PseudoDamage

Pseudo Damage refers to the completion skin factors which account for the modified geometry of an actual well compared to that assumed in avertical radial flow well, which fully penetrates the reservoir.

Pulling Tool A Pulling Tool is used in wireline and coiled tubing operations toretrieve a lock mandrel from the well.

Pump down Pump down tools can be installed inside tubing and production stringsusing hydraulic pressure.





Pup (joint) A Pup Joint is a short length of tubing, normally between 2 and 20ft andis used to facilitate space-out and positioning of equipment.

Q Quench This is a process used in manufacturing carbon steels whereby the

steel upon hardening is then placed on a bath of water or other fluid toaccelerate cooling.

Quick Release This refers to couplings, such as those used on a bottom lubricator jointto allow quick and safe connection to the wellhead.

R ‘R’ Nipple Baker R Nipple – a positive locking non-selective nipple profile, typicallyused as a tailpipe component for installing flow control devices.

Ram A Ram refers to a piece of well control equipment which is normally part

of a blow-out preventer stack. The Ram could either be designed toclose-off the wellbore around a particular size of pipe or wire, or couldbe designed to shear or close-off the entire well cross-sectional area.

RetrievalPacker

This refers to a packer system which can be easily pulled from thewellbore, normally by reversing the setting process. In many cases, aretrieval packer is uni-directional, and can only withstand force or differential pressure from one direction.

Retrieve To pull from the tubing or the well

Ring Gasket Ring Gasket is normally designed as a circular seal system placed

between the flanges on a wellhead. A ring gasket is compressed andprovides a seal to prevent the release of fluids.

Riser This is a generic term used to refer to a pipe which is installed on top of a well and allows fluids and tools to be pulled back to a rig above thewell.

Run In To lower into the well

Straightener Straightener is used in coiled tubing operations to alleviate thecurvature of the pipe such that it is straight prior to injections throughthe injector head.

S S.C.F. Standard Cubic Feet as measured at 1 atmosphere pressure and 60oF.

S.P.M Side Pocket Mandrel

S.S.D. Sliding Side Door

S.T.B. Stop Tank Barrel – A barrel of fluid measured at standard conditions of 1 atmosphere and 60oF.

Safety Valve This is a valve used to provide closure of a well stream.





Scale An inorganic precipitate created by the mixing of incompatible fluids,typically water, and their flow towards a zone of lower temperature andpressure where the solubility limit is exceeded.

Screen-out Screen-out occurs during hydraulic fracturing treatments when the

granular material or proppant can no longer be injected into thefracture, and therefore accumulates at a restriction such as theperforation tunnel or in the mouth of the fracture itself.

Screens Screens refer to a range of tubular devices which are run into thebottom of a well and are designed to restrict the movement of solidswith produced fluids from the reservoir.

Seal A means of sealing one component within another. The seal can either be a deformable material, such as an elastomer or could be a metal tometal seal.

Seal Assembly A series of seals, typically located on one tubular component, either internally or externally which is then engaged into another tubular system.

Sealbore The tubular surface, for example within a packer, in which a sealassembly will engage.

Selective A Selective (as in nipple profile) refers to a nipple profile system inwhich a number of positions can be entered, thus allowing a series of similar size nipple profiles to be installed inside the same tubing stringat different depths.

Set Down This refers to the amount of weight or force applied, for example, to apacker during installation.

Shear Pin A pin typically used to hold components together that can be shearedout by load conditions created either mechanically or hydraulically.

Shifting Tool This refers to an operating tool used in coiled tubing and wirelineoperations which is run down inside a device such as a sliding sidedoor or sliding sleeve, and is used to move the inner sleeve either upwards or downwards.

Side Outlet Side Outlet is an opening on the side of spools and housings to whichis attached a tube, a flange and a valve. It allows hydraulic access totubular annuli.

Skin Factor Skin Factor is used to mathematically define the impact on wellperformance due to imposed geometrical or damage which results inreduced fluid conductivity within the reservoir.

Slick Plug Slick Plug refers to a system used to install a plug inside a well,typically without the need for a nipple profile.

Slickline Slickline is a wireline system used for well servicing and refers to asingle strand cable.





Slips Slips are a series of tapered segments which are used within a bowl toallow pipe to be landed off inside the hanger bowl.

Snubbing The capacity to push pipe into a well against a positive tubing headpressure. The positive tubing head pressure will provide an upwards

force which has to be overcome to allow the pipe to be inserted.

Space-out To position tubular components to provide a specified amount of space,such that movement of the pipe can be accepted, for example, inpositioning seal assemblies to accommodate expansion andcontraction.

Splined Unit Splined Unit consists of two tubular components which have a splinedsurface, and when engaged allow relative motion in the actual direction,but can also allow torque to be applied via the spline units. It is used insome multiple string completions to allow space-out but also to allow

rotation.

Stab In To push one component onto another, for example a seal assemblyinto a packer bore.

Stationery /Travelling Slips

These are used on hydraulic workovers and provide for pipe retrievalfrom the well.

Storm Choke This is a term used to define a sub-set of safety valves which isactuated by a change in the flowing conditions sub-surface, namelybottomhole pressure or flowrate.

StratacoilTM A temporary sand exclusion screen which can be run into the wellretrospectively and landed off the tailpipe to provide sand control.

StratapackTM These refer to premium screens supplied by Pall Well Technology.

Sub-surfaceSafety Valve

This is a valve installed as a part of the tubing string whose function isto provide emergency downhole shut-off to prevent a catastrophicrelease of fluids or pressures at surface.

Swab Swab is the process of inducing flow from a well by creating a pistoneffect at the base of the well by reciprocation.

T C I T H P Closed-in Tubing Head Pressure

F T H P Flowing Tubing Head Pressure

T C P Tubing conveyed perforating. This refers to the process of lowering aperforating gun on tubing into the well. The tubing could be either conventional production tubing or a drillpipe running string or coiledtubing.

T F L Thru-flow Line or pump down for which a tool string comprising tools

comparable to conventional wireline tools is hydraulically pushed downthe inside of a flow line and into the tubing string. Reversal of flow





allows retrieval of the tool string. It is clearly a well servicing techniquefor subsea wells.

T H P Tubing Head Pressure

Tag Tag refers to the process of lowering pipe into the hole until it contactsthe sealbore or packer. It may also refer to the process of placing aradioactive tracer into a slurry which allows monitoring of its progress.

Tail This refers to a second or last portion of a slurry, such as cement in aprimary cement job, or a fractured treatment. In fracturing, a tailproppant often is going to be either a higher US mesh size providinghigher conductivity, or maybe may consist of resin coated gravel whichwill thermally set upon placement and lock the proppant into thefracture.

Tailpipe This is a length of tubing at the base of the completion string and issuspended either directly from the packer or from the tubing itself. Itcontains a series of devices that provide isolation and monitoringcapabilities.

Tell Tale Tell tale is a screen which is run in gravel packing at the bottom and / or the top of the main screen system. It provides indications of gravelplacement into the annulus behind the screen, and the presence of areserve of gravel which will protect the entire main screen upon jailbreak.

Temper This refers to the process of working mechanically the steel to improve

its strength and machinable properties.

Template A template is a base used to allow construction of the well by loweringthe individual casing strings and subsequent production tubing with itswellhead onto the base of the seabed.

Tensile Load Refers to the tensile weight of tubing, pipe or tools suspended from astring of tubing or wire.

Tip As in perforations, refers to the end of the perforation tunnel which iscreated into the formation.

Tip Screen-out Tip Screen-out refers to the process in sand control or proppedhydraulic fracturing in which the proppant, when injected, bridges at thetip and compacts from there back towards the wellbore.

Tool Trap Tool trap is typically located at the bottom of a wireline lubricator. Itconsists of a string loaded pin which is actuated once a tool has beenpulled through the wireline BOP into the lubricator. Its function is toprevent loss of the tool if the wire breaks at the rope socket when itcomes into contact with the top of the lubricator.

Torque Turn Refers to a device which will count the number of rotations which pipe

undergoes when threads are engaged and torque is applied. it isimperative in the case of premium type threads that clean threads areprovided which allow the required torque make-up.





Tubing Head Tubing Head refers to the top of completion string, refer CITHP andFTHP.

U U-Tube This refers to the hydraulic process of circulating between 2 tubing

strings providing an annulus, for example, the tubing and the annulusbetween the casing and the tubing.

U S ITM Schlumberger

Is the Ultrasonic Imaging Tool and uses ultrasonics to monitor the near wellbore integrity and bonding around a casing string.

Underbalance

V V A M Refers to a series of threads which were developed by a Companycalled Fallourec primarily to provide high pressure sealing for gas wells.They are a commonly used premium thread for high pressure and

premium applications.

V Packing V Packing refers to a circular packing element which has a V crosssection. Ring elements are placed in opposing orientations which whenenergised by pressure between them, provide a seal which is resilientto differential pressure from either direction. An energised V packingwill provide drag when the tool, for example the wireline tool, is pulledout of a nipple profile.

W Wax This is a heavy end deposit from a paraffinic crude and typicallyconsists of high molecular weight components. The solubility of the

wax decreases with declining temperature and as such, the wax candeposit out of the liquid oil system inside the tubing string.

Weight Set Weight set refers to the process of achieving setting of devices such aspackers by either slacking off or pulling weight, ie tension, on the string.The transfer of the weight or tensile load through a setting mandrel willachieve setting of the packer elements and slips.

Wellhead Wellhead refers to the system which is used to allow constructionmechanically of the well and allows the suspension of the individualcasing strings sequentially into the well as the hole is deepened and thebit size reduces.

Wing Valve This refers to the control valves which are located on the side outlets of a Xmas tree or wellhead spool. They are commonly utilised asproduction or flow wing and kill wing valves on the Xmas tree.

Wireline This refers to the process which utilises either single strand wire (pianowire) or braided cable consisting of a number of wires twisted together,which can be manufactured with or without a central copper conductor for data transmitter. The process is used to lower, install and operatetools within the wellbore.

Wireline Valve A Wireline Valve is a colloquial term used to refer to the wireline BOPused to provide closure of the lubricator against either the openhole or





with the wire in place.

WirewrapScreen

A Wirewrap Screen consists of a predrilled base pipe as around itsoutside surface is wrapped a wire. The closeness of spacing of thewraps provides a predetermined slot size which can be useful for sand

control or gravel pack operations.

Work (Steel) This refers to the process of manipulating a solidifying steel throughheat and mechanical processes to modify its strength requirements andcorrosion susceptibility.

Workover A Workover primarily refers to an intervention process which involvesthe retrieval of production tubing to allow its replacement or thereplacement of individual components.

X Xmas Tree This is a flow control device which is landed out on top of the wellheadand provides control hydraulically of fluid movement into and out of thewell, as well as all mechanical access down the inside of the tubing, for example, wireline tools. Xmas tree consists of master valves, swampvalves and wing valves.

X NippleTM Halliburton

The X Nipple refers to a range of wireline nipple systems for smaller tubing sizes, typically 3½ inch or less in diameter. It is available asprimarily a selective nipple profile with corresponding mandrels to allowpositioning and installation of equipment inside the well.

Y Y Spool Y Spool refers to a spool system which is used on a wellhead or on aXmas tree, and is bored out in the form of a ‘Y’. In this way, the fluid or fluid exit from the Xmas tree is reduced in severity, in terms of itsangular change, and this results in less pressure drop and impingementwhich would result in erosion.

Yield Yield, as in strength, refers to the amount of force typically tensile loador pressure which is required to create collapse or tensile failure of thepipe.

Yield Strength This is frequently referred to as the minimum Yield Strength and is theminimum tensile load at which the pipe will fail in tensile mode.


Documents

Glossary of Terms