Block Valve

Block Valve

Definition(s)

Block Valve

Valve that is either open or closed; used to isolated equipment or pipeline sections. Source: IADC UBO / MPD Glossary, December 2011. Global Standards
Bleed Off Line

Bleed Off Line

Definition(s)

Bleed Off Line

Component of pressure containment system on a snubbing stack to drain cavity and reduce trapped wellbore pressure. Source: IADC UBO / MPD Glossary, December 2011. Global Standards
Best Efficiency Point

Best Efficiency Point

Definition(s)

Best Efficiency Point (BEP)

Point on the speed- efficiency curve where the pump or compressor is operating at its highest efficiency. Source: IADC UBO / MPD Glossary, December 2011. Global Standards
Bernoulli’s Principle

Bernoulli’s Principle

Definition(s)

Bernoulli's Principle

Liquid pressure is inversely proportional to the square of liquid velocity. Source: IADC UBO / MPD Glossary, December 2011. Global Standards
Bernoulli’s Equation

Bernoulli’s Equation

Definition(s)

Bernoulli's Equation

Relates to the total energy at two points in an incompressible liquid flowing at a steady rate. Source: IADC UBO / MPD Glossary, December 2011. Global Standards
Base Load

Base Load

Definition(s)

Base Load

Minimum load. Source: IADC UBO / MPD Glossary, December 2011. Global Standards
Ball Check Valve

Ball Check Valve

Definition(s)

Ball Check Valve

A valve permitting flow in one direction only by lifting a spring-loaded ball off its seat. Valve opens when pressure differential acts in the desired flow direction. The valve seals by forcing the ball tightly against the seat when a pressure differential acts opposite the desired flow direction. Source: IADC UBO / MPD Glossary, December 2011. Global Standards
Balance

Balance

Definition(s)

Balance

Steady state of flow line or vessel has three critical characteristics:
  1. a single flow rate from node to node;
  2. an even pack throughout the system; and
  3. approximately equal volumes entering and leaving the line or vessel.
Source: IADC UBO / MPD Glossary, December 2011. Global Standards
Aromatics

Aromatics

Definition(s)

Aromatics

Ring group chemical structure. Most common are benzene, toluene, and xylene. Source: IADC UBO / MPD Glossary, December 2011. Global Standards
Apparent Viscosity

Apparent Viscosity

Definition(s)

Apparent Viscosity

Slope of the shear stress versus velocity gradient for a fluid. For Newtonian fluids, the apparent viscosity equals the absolute viscosity. Source: IADC UBO / MPD Glossary, December 2011. Global Standards
Apparent Power

Apparent Power

Definition(s)

Apparent Power

Combination of real and reactive power. Source: IADC UBO / MPD Glossary, December 2011. Global Standards
API Gravity

API Gravity

Definition(s)

API Gravity

Arbitrary measurement of density adopted in 1921 by the American Petroleum Institute and the Bureau of Standards. Source: IADC UBO / MPD Glossary, December 2011. Global Standards
Aniline Point

Aniline Point

Definition(s)

Aniline Point

The aromatics content of a hydrocarbon mixture. Source: IADC UBO / MPD Glossary, December 2011. Global Standards
American Standard Code for Information Interchange (ASCII)

American Standard Code for Information Interchange (ASCII)

Definition(s)

American Standard Code for Information Interchange (ASCII)

A different byte represents each number, letter, symbol and punctuation mark. Replaced by Unicode. Source: IADC UBO / MPD Glossary, December 2011. Global Standards
Affinity Laws

Affinity Laws

Definition(s)

Affinity Laws

Equations that correlate the relationship of head, speed, impeller diameter, flow, and efficiency for turbo machinery. Source: IADC UBO / MPD Glossary, December 2011. Global Standards
Air Cutting

Air Cutting

Definition(s)

Air Cutting

Inadvertently incorporating and dispersing air (mechanically) into a drilling fluid system. Source: IADC UBO / MPD Glossary, December 2011. Global Standards
Aftercooler

Aftercooler

Definition(s)

Aftercooler

Heat exchanger used post compression to reduce gas temperatures. Source: IADC UBO / MPD Glossary, December 2011. Global Standards
Aeration

Aeration

Definition(s)

Aeration

Injecting gases in varying amounts into a fluid. Source: IADC UBO / MPD Glossary, December 2011. Global Standards
Adjustable Choke

Adjustable Choke

Definition(s)

Adjustable Choke

A choke with a conical needle and seat vary the rate of flow. See also chokes. Source: IADC UBO / MPD Glossary, December 2011. Global Standards
Adequately Ventilated Area

Adequately Ventilated Area

Definition(s)

Adequately Ventilated Area

Is an area having a natural or artificial ventilation system to prevent the accumulation of gases to an explosive level. API Recommends 12 air volume changes per hour or 1.5 CFM per square foot of floor area whichever is greater. Source: IADC UBO / MPD Glossary, December 2011. Global Standards
Adiabatic Efficiency

Adiabatic Efficiency

Definition(s)

Adiabatic Efficiency

Ratio of theoretical temperature increase to actual temperature increase; a measure of the work done by a compressor that is not lost as heat. Source: IADC UBO / MPD Glossary, December 2011. Global Standards
Adiabatic

Adiabatic

Definition(s)

Adiabatic

Process that is at constant temperature without loss or gain of heat. Source: IADC UBO / MPD Glossary, December 2011. Global Standards
Actuators

Actuators

Definition(s)

Actuators

Part of a control system, which regulates speed, power, valve position, etc. to match a set point. Source: IADC UBO / MPD Glossary, December 2011. Global Standards
Active Data

Active Data

Definition(s)

Active Data

continually updated data, based on latest operational data.. Source: IADC UBO / MPD Glossary, December 2011. Global Standards
Acceleration

Acceleration

Definition(s)

Acceleration

Rate of change in velocity. Source: IADC UBO / MPD Glossary, December 2011. Global Standards
Absolute Zero Temperature

Absolute Zero Temperature

Definition(s)

Absolute Zero Temperature

Temperature that prevents molecular motion. Source: IADC UBO / MPD Glossary, December 2011. Global Standards
Absolute Viscosity

Absolute Viscosity

Definition(s)

Absolute Viscosity

dynamic relationship between a force and the fluid motion. Source: IADC UBO / MPD Glossary, December 2011. Global Standards
Absolute Temperature

Absolute Temperature

Definition(s)

Absolute Temperature

Temperature measured with respect to absolute zero, in degrees Rankine or degrees Kelvin. Source: IADC UBO / MPD Glossary, December 2011. Global Standards
Absolute Pressure

Absolute Pressure

Definition(s)

Absolute Pressure

Internal pressure that the equipment is designed to contain and/or control, or that is zero-referenced against a perfect vacuum; measured in “psia”. Source: API Specification 16A, Specification for Drill-through Equipment, Fourth Edition, April 2017. Global Standards

Absolute Pressure

Hydrostatic pressure plus applied pressure.

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

Absolute Pressure

Pressure measured with respect to zero pressure; the sum of atmospheric pressure and gauge pressure. Source: IADC UBO / MPD Glossary, December 2011. Global Standards
SITP

SITP

Definition(s)

SITP

Shut-in tubing pressure. Source: API Standard 2RD, Dynamic Risers for Floating Production Systems, Second Edition, September 2013. Global Standards