Glossary
Browse the IADC Lexicon alphabetically or by category. Get comprehensive definitions of drilling industry terms.
Pressure Control Valve (PCV)
Definition(s)
Pressure Control Valve (PCV)
Valve that regulates pressures at stations, restricting flow by use of a ball or plug positioned by an actuator. Source: IADC UBO / MPD Glossary, December 2011. Global StandardsPressure Control
Definition(s)
Pressure Control
Operational limit based on either the line or vessel suction pressure or the discharge pressure at a station. Source: IADC UBO / MPD Glossary, December 2011. Global StandardsPredictive Model
Definition(s)
Predictive Model
Performs "what if" analyses by calculating the effects of transients introduced by scheduled or unscheduled line or vessel events, such as pump or compressor outages, valve closures, or supply variations. The operator typically enters these events into a "scenario".. Source: IADC UBO / MPD Glossary, December 2011. Global StandardsPower Factor
Definition(s)
Power Factor
Ratio of real power (measured in Hp (kW)) and apparent power (measured in kVAr).. Source: IADC UBO / MPD Glossary, December 2011. Global StandardsPower (p)
Definition(s)
Power (p)
Rate of doing work. Source: IADC UBO / MPD Glossary, December 2011. Global StandardsPour Point
Definition(s)
Pour Point
Lowest temperature at which a liquid will pour, or flow. Source: IADC UBO / MPD Glossary, December 2011. Global StandardsPotential or Head Energy
Definition(s)
Potential or Head Energy
Energy that can be converted to velocity or flow; this pressure is created through changes in elevation or by pump units that are equivalent to positive changes in elevation. Source: IADC UBO / MPD Glossary, December 2011. Global StandardsPotential Energy
Definition(s)
Potential Energy
Energy of position (usually the energy input to the system such as at pumps. Source: IADC UBO / MPD Glossary, December 2011. Global StandardsPositive Choke
Definition(s)
Positive Choke
Choke requiring orifice size change to change the rate of flow. Source: IADC UBO / MPD Glossary, December 2011. Global StandardsPocket (unloader)
Definition(s)
Pocket (unloader)
Reduces the flow through a reciprocating compressor by increasing the volumetric capacity of the compressor cylinder. Source: IADC UBO / MPD Glossary, December 2011. Global StandardsPit Level Indicator
Definition(s)
Pit Level Indicator
Device that constantly monitors the level of drilling fluid in the pits during operations incorporates float devices with sensors that report levels to a recording and alarm device (the pit volume recorder) placed near the driller’s position on the rig floor, the alarm is set to sound if the pit level goes too high or too low. Source: IADC UBO / MPD Glossary, December 2011. Global StandardsPiping and Instrumentation Diagram (P&ID)
Definition(s)
Piping and Instrumentation Diagram (P&ID)
Diagram showing the sequence of piping and instruments on a section of the line or vessel but not drawn to scale. Source: IADC UBO / MPD Glossary, December 2011. Global StandardsPipe Work (surface pipe connections)
Definition(s)
Pipe Work (surface pipe connections)
May be threaded, unions, clamps, or flanged. Flanged connections are preferable (not mandatory) especially in the higher pressure applications, unions and clamps are acceptable in low to medium pressure, functions, threaded connections are appropriate in low pressure operations only and care must be taken to avoid galling / thread damage. Source: IADC UBO / MPD Glossary, December 2011. Global StandardsPipe Prover
Definition(s)
Pipe Prover
Common device used in the proving of a meter. Source: IADC UBO / MPD Glossary, December 2011. Global StandardsPipe light
Definition(s)
Pipe light
A condition when the force acting on the drillstring from the wellbore pressure exceeds the weight of the drillstring. Source: IADC UBO / MPD Glossary, December 2011. Global StandardsPipe Leg
Definition(s)
Pipe Leg
Modeling term. Source: IADC UBO / MPD Glossary, December 2011. Global StandardsPig Time
Definition(s)
Pig Time
Time required for a "pig" to traverse a section of line or vessel. Source: IADC UBO / MPD Glossary, December 2011. Global StandardsPig (pigged)
Definition(s)
Pig (pigged)
Device, which may contain instruments, propelled by fluid down the line to clean pipe walls, gather information about the pipe, or separate different batches of fluid Source: IADC UBO / MPD Glossary, December 2011. Global StandardsPiezometric Pressure
Definition(s)
Piezometric Pressure
Pipe pressure plus elevation pressure. Source: IADC UBO / MPD Glossary, December 2011. Global StandardsPeak Shaving
Definition(s)
Peak Shaving
- technique used to shift a portion of an electrical load at a peak time of day to a non-peak time;
- technique used to meet peek demands using alternate gas supplies such as storage, LNG or propane air.