S

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Static

Usually refers to a pipe segment with no flow. Source: IADC UBO / MPD Glossary, December 2011. Global Standards

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Standard Temperature

Temperature used to correct volumes to a standard volume. Source: IADC UBO / MPD Glossary, December 2011. Global Standards

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Squeeze Job

Remedial operation to pump cement slurry down a well into open perforations, formation cavities etc, to create a blockage. Source: IADC UBO / MPD Glossary, December 2011. Global Standards

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Square Law

Relationship between velocity and the pressure drop in the pipe, where for over a limited range of flows, pressure drop is proportional to the square of the velocity for flow rate (also called capacity). Source: IADC UBO / MPD Glossary, December 2011. Global Standards

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Spitzglas Formula

Equation used for calculating flow in small diameter, low-pressure distribution lines. Source: IADC UBO / MPD Glossary, December 2011. Global Standards

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Specific Weight

Substance weight divided by its volume. Source: IADC UBO / MPD Glossary, December 2011. Global Standards

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Specific Speed

Design index that gives a general indication of the overall performance and geometry of the pump and impeller. Source: IADC UBO / MPD Glossary, December 2011. Global Standards

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Specific Heat Ratio

Ratio of specific heats at constant pressure and constant volume. Source: IADC UBO / MPD Glossary, December 2011. Global Standards

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Specific gravity

1. measure which compares the density of any liquid with the density of water at the reference temperature.
2. weight of a given volume of gas compared under standard conditions to an equal volume of dry air.

Source: IADC UBO / MPD Glossary, December 2011. Global Standards

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Sour Water (handling)

Water contaminated with hydrogen sulfide (H2S). Run through a degasser (poor boy, vane type etc) and pass to a tank before disposal.. Source: IADC UBO / MPD Glossary, December 2011. Global Standards

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Sour Fluids

In underbalance drilling operations, where sour fluids are expected a closed system is utilized to meet recognized industry standards for handling such fluids. Source: IADC UBO / MPD Glossary, December 2011. Global Standards

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Sour

Hydrocarbon fluids containing sulfur. Generally taken as greater than or equal to 10-ppm, the 8 hour occupational exposure limit. Source: IADC UBO / MPD Glossary, December 2011. Global Standards

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Sonic Wave Speed

Speed at which a transient wave travels through a line or vessel. It depends on fluid properties, and the elastic modulus of the pipe. Source: IADC UBO / MPD Glossary, December 2011. Global Standards

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Sonic Flow Meter

Device for measuring fluid flow by timing sound waves across a cross-section of pipe. Source: IADC UBO / MPD Glossary, December 2011. Global Standards

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Solubility

Capacity of a substance to be dissolved. Source: IADC UBO / MPD Glossary, December 2011. Global Standards

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Soft Start

with VFD, logic circuit increases AC power gradually until the motor has reached full speed. Source: IADC UBO / MPD Glossary, December 2011. Global Standards

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Soft Shut In

To shut in a well by closing the blowout preventer with the choke and choke line valve open, then closing the choke while monitoring the casing pressure gage for maximum allowable casing pressure. Source: IADC UBO / MPD Glossary, December 2011. Global Standards

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Soft Shutdown

Using the VFD to slow the motor before stopping. Source: IADC UBO / MPD Glossary, December 2011. Global Standards

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Slug Flow

A multiphase fluid-flow regime where the gas and liquid phase are discrete over portions of the flow. Generally occurs in combination with bubble flow. Flow will vary from high liquid to high gas cuts. Also called Line Jacking. Source: IADC UBO / MPD Glossary, December 2011. Global Standards

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Slack Pipeline

Maintaining column separation at a location with an extreme drop in elevation so that the pressure does not exceed the maximum operating pressure (MOP). Source: IADC UBO / MPD Glossary, December 2011. Global Standards

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Single Stage Pump

One impeller and single stage of pressurization. Source: IADC UBO / MPD Glossary, December 2011. Global Standards

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Shut-off Head

Head delivered by the pump at zero flow. Source: IADC UBO / MPD Glossary, December 2011. Global Standards

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Shutdown Valves, Emergency

Used to shut down flow line from rotating head in emergency situations, preferably butterfly or similar quick - closing design See ESD. Source: IADC UBO / MPD Glossary, December 2011. Global Standards

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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 Standards

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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 Standards

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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 Standards

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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 Standards

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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 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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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 Standards