Glossary
Browse the IADC Lexicon alphabetically or by category. Get comprehensive definitions of drilling industry terms.
Sight Windows
Definition(s)
Sight Windows
Sight windows are an effective and economical way of viewing tank, pressure vessel and piping systems interiors. Also referred to as a sight glass. Source: IADC UBO / MPD Glossary, December 2011. Global StandardsShipping Pumps
Definition(s)
Shipping Pumps
Typically centrifugal in design, used to transport drilling fluids to the suction tank and produced fluids to the storage facility. Mostly activated manually, but some float activated pumps are in use. Source: IADC UBO / MPD Glossary, December 2011. Global StandardsSet Point
Definition(s)
Set Point
Preset value that is the desired value of a variable, such as suction or discharge pressure. Source: IADC UBO / MPD Glossary, December 2011. Global StandardsSeries Configuration
Definition(s)
Series Configuration
A configuration of pumps or compressors linked together so that the discharge of one pump or compressor enters the inlet of another. Heads are additive at the same flow series/parallel operation flow is divided between the series pumps/compressors and the parallel pumps/compressors according to the capacity of each of the units. Source: IADC UBO / MPD Glossary, December 2011. Global StandardsSediment and Water (S&W)
Definition(s)
Sediment and Water (S&W)
Dissolved impurities such as salt, water, asphalt and other substances in crude oil, which come out of suspension and sink to the bottom of a container as the oil cools and settles. Source: IADC UBO / MPD Glossary, December 2011. Global StandardsSeat, Casing
Definition(s)
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 StandardsScraper Pig
Definition(s)
Scraper Pig
Pig equipped with brushes or urethane blades used to clean line or vessels; see also: pig. Source: IADC UBO / MPD Glossary, December 2011. Global StandardsScraper
Definition(s)
Scraper
Pigging device for cleaning paraffin or other substances from the inside surface of a pipeline. See pig. Source: IADC UBO / MPD Glossary, December 2011. Global StandardsSample Catcher
Definition(s)
Sample Catcher
Designed to take a portion of the flow from the wellbore, direct it through a chamber to remove drilled solids but reject liquids and gas. Source: IADC UBO / MPD Glossary, December 2011. Global StandardsSafety Valves (pop offs)
Definition(s)
Safety Valves (pop offs)
Valves most commonly used for temperature or pressure relief. Ensure venting from these valves terminate in a safe area. Source: IADC UBO / MPD Glossary, December 2011. Global StandardsRupture disc
Definition(s)
Rupture disc
Device that relieves pressure when an absolute pressure value is high enough to rupture the disc material, thus allowing fluid to flow into some type of a vessel. Source: IADC UBO / MPD Glossary, December 2011. Global StandardsRTU
Definition(s)
RTU
Remote transmission (terminal) unit used in telemetry (SCADA) systems to transmit operating information to a master terminal unit (MTU) usually located in a control center. Source: IADC UBO / MPD Glossary, December 2011. Global StandardsRTU
Remote Terminal Unit. Source: ANSI/ISA–99.00.01–2007, Security for Industrial Automation and Control Systems, Part 1: Terminology, Concepts, and Models, 29 October 2007. National StandardRoughness
Definition(s)
Roughness
Measure of the surface condition of the internal wall of pipe; Roughness can change with the age of the pipe and the type of service it has provided. Source: IADC UBO / MPD Glossary, December 2011. Global StandardsRotating Blowout Preventer
Definition(s)
Rotating Blowout Preventer
(Rotating annular preventer designed to rotate with pipe and seal on both pipe and kelly while allowing upward and downward movement of the pipe – also known as RBOP) Design specific to underbalance drilling. Models available for both top drive and Kelly drive applications. Source: IADC UBO / MPD Glossary, December 2011. Global StandardsRotating Diverter
Definition(s)
Rotating Diverter
Generic term, - sometimes used to mean rotating head, or rotating blowout preventer. Source: IADC UBO / MPD Glossary, December 2011. Global StandardsRotary Motion Valve
Definition(s)
Rotary Motion Valve
Valve whose closure member rotates opening or closing rotating equipment, centrifugal pumps, or compressors. Source: IADC UBO / MPD Glossary, December 2011. Global StandardsRising Characteristic Curve
Definition(s)
Rising Characteristic Curve
Preferred curve shape for pump H-Q curves; this curve has a steady increase of H with decreasing Q. Source: IADC UBO / MPD Glossary, December 2011. Global StandardsReynolds Number
Definition(s)
Reynolds Number
Mathematical relationship that describes the interdependence between the pipe diameter, fluid viscosity, and flow velocity; a dimensionless number used to describe the type of flow exhibited by a fluid flowing through a pipe. Source: IADC UBO / MPD Glossary, December 2011. Global StandardsReturn System
Definition(s)
Return System
Handles returns from the well – injected fluids, (gas and liquid) cuttings, hydrocarbons, formation water etc. Consists of flow diverter, flow cross, emergency shut down valve, choke manifold, pressure vessel and solids control equipment, from where the liquid phase used for drilling is passed on to the drilling fluid tank, and then to the rig pumps for re injection to the well. Source: IADC UBO / MPD Glossary, December 2011. Global StandardsReport by Exception
Definition(s)
Report by Exception
RTU sends information to the Host when data has changed by a specified amount. Source: IADC UBO / MPD Glossary, December 2011. Global StandardsRemote Terminal Unit (RTU)
Definition(s)
Remote Terminal Unit (RTU)
Computer located at a remote location that gathers the information provided by all the PLCs at the location, and transmits that information back to the host computer. Source: IADC UBO / MPD Glossary, December 2011. Global StandardsRemote Station
Definition(s)
Remote Station
Auxiliary controls for operating a blowout preventer. Source: IADC UBO / MPD Glossary, December 2011. Global StandardsRemote Choke Panel
Definition(s)
Remote Choke Panel
A set of controls, usually placed on the rig floor, used to control the amount of fluid circulated out through the choke manifold. Source: IADC UBO / MPD Glossary, December 2011. Global StandardsRelative Roughness
Definition(s)
Relative Roughness
Ratio of the absolute roughness of the inside pipe wall to the internal diameter of the pipe; Absolute roughness is the average height of imperfections in the pipe wall surface. Source: IADC UBO / MPD Glossary, December 2011. Global StandardsReid Vapor Pressure
Definition(s)
Reid Vapor Pressure
A test method to determine the vapor pressure of volatile petroleum liquids at 100° F with an initial boiling point above 32° F. (ASTM D 323) Source: IADC UBO / MPD Glossary, December 2011. Global StandardsReference Level
Definition(s)
Reference Level
Zero elevation/head on a total energy diagram. For line or vessel applications, the reference level is usually sea level. Source: IADC UBO / MPD Glossary, December 2011. Global StandardsRecycle Line
Definition(s)
Recycle Line
Gas line that allows re-circulation of discharge gas into the suction side of a centrifugal compressor; this permits a centrifugal compressor to be placed on-line or off-line in parallel with other units without creating a surge condition. Source: IADC UBO / MPD Glossary, December 2011. Global StandardsRecoverable Energy
Definition(s)
Recoverable Energy
Head below the total headline; energy which is still useful for moving oil down the line or vessel. Source: IADC UBO / MPD Glossary, December 2011. Global StandardsReciprocating Compressor
Definition(s)
Reciprocating Compressor
- a piston-type positive displacement compressor which increases the pressure of a definite volume of gas by reducing the cylinder volume, resulting in a pulsating delivery of gas;
- any compressor which employs a piston working inside a cylinder to compress a gas; usually has "pockets" that allow for limited pressure and flow control.