Glossary
Browse the IADC Lexicon alphabetically or by category. Get comprehensive definitions of drilling industry terms.
Reactive MPD
Definition(s)
Reactive MPD
Using MPD methods and/or equipment as a contingency to mitigate drilling problems as they arise. Source: IADC UBO / MPD Glossary, December 2011. Global StandardsRate of Rise
Definition(s)
Rate of Rise
Surge control in which a pressure sensor initiates a device control that is proportional to the rate of pressure increase caused by the surge. Source: IADC UBO / MPD Glossary, December 2011. Global StandardsRankine
Definition(s)
Rankine
(degrees temperature) - English measurement of absolute temperature (+459.69 offset). Source: IADC UBO / MPD Glossary, December 2011. Global StandardsRamping
Definition(s)
Ramping
- Gradual startup or shutdown of a pump unit.
- Modeling term meaning to change variables with time.
Quick Opening Valve Flow Characteristic
Definition(s)
Quick Opening Valve Flow Characteristic
Produces a very rapid increase in flow between the closed position and the partially open position. Source: IADC UBO / MPD Glossary, December 2011. Global StandardsPVR (Plant Volume Reduction)
Definition(s)
PVR (Plant Volume Reduction)
The volume of gas removed from a line or vessel at a hydrocarbon processing plant. Source: IADC UBO / MPD Glossary, December 2011. Global StandardsPurge
Definition(s)
Purge
Procedure that removes all air from a line or vessel to prevent fire or corrosion. The length of time required to purge a line is dependent on the size and length of the line, size of the blow off valve, and the purging method selected. Source: IADC UBO / MPD Glossary, December 2011. Global StandardsPump Unit Shutdown
Definition(s)
Pump Unit Shutdown
Temporary loss of a pump unit, indicates exceeded one or more of the pump's operating parameters. Source: IADC UBO / MPD Glossary, December 2011. Global StandardsPump Unit Lockout
Definition(s)
Pump Unit Lockout
Removal from service of a shutdown pump unit. Source: IADC UBO / MPD Glossary, December 2011. Global StandardsPump Station
Definition(s)
Pump Station
One of the installations built at intervals along a liquid line or vessel to route and increase the flow contains pumps and other equipment.
Pump Run Out
Definition(s)
Pump Run Out
Flow rate that produces little to no head. Source: IADC UBO / MPD Glossary, December 2011. Global StandardsPump Horsepower Capacity Curve
Definition(s)
Pump Horsepower Capacity Curve
Graphical representation of required power versus flow. Source: IADC UBO / MPD Glossary, December 2011. Global StandardsPump Head-capacity Curve
Definition(s)
Pump Head-capacity Curve
Graphical representation of pressure produced by the pump vs. flow rate. Source: IADC UBO / MPD Glossary, December 2011. Global StandardsPump Head
Definition(s)
Pump Head
Amount of the increase in total head across the pump. Also referred to as pump differential head.. Source: IADC UBO / MPD Glossary, December 2011. Global StandardsPump Differential Head
Definition(s)
Pump Differential Head
Difference in total head between the suction and discharge of the pump. Source: IADC UBO / MPD Glossary, December 2011. Global StandardsPump Differential
Definition(s)
Pump Differential
Total pressure output of a pump minus its suction pressure. Source: IADC UBO / MPD Glossary, December 2011. Global StandardsPump Curve
Definition(s)
Pump Curve
Graph that shows the relationship between flow, head, horsepower, efficiency, and NPSHR of a pump. Source: IADC UBO / MPD Glossary, December 2011. Global StandardsPump Capacity
Definition(s)
Pump Capacity
Flow rate of a pump at a particular head as read off the pump head-capacity curve. Source: IADC UBO / MPD Glossary, December 2011. Global StandardsPressure Vessel –Phase Separation
Definition(s)
Pressure Vessel –Phase Separation
First Option. Single four – phase separation vessel using velocity drop in the first compartment to create gas and solids phase separation. Liquids cascade to the back compartments where with sufficient residence time the interface forms. Requires sufficient time for the interface between liquids to take place which means the vessel has to be correspondingly large to accomplish the process. Second Option. A series of vessels designed to separate the phases sequentially. Order of phase separation may vary from system to system. Different systems available are: Gas to be separated first as it is compressible and of lower density than solids or liquids. Remove solids first as they will erode pipe work and components in the system. Separation of gas, solids, and liquids occurs in individual hydro-cyclones connected in series, parallel, or a combination of both. In all separators, the design should make it impossible for gas to travel down the liquid leg and liquid to travel down the gas leg. Source: IADC UBO / MPD Glossary, December 2011. Global StandardsProportional Integral Derivative (PID)
Definition(s)
Proportional Integral Derivative (PID)
Controller that uses all terms in determining the movement to meet the set point. Source: IADC UBO / MPD Glossary, December 2011. Global StandardsProcess Disturbances
Definition(s)
Process Disturbances
Things that change the steady state of a control system profile.- Horizontal line that indicates changes in ground elevation along the line or vessel route.
- Modeling term used to define changes with respect to time.
Proactive MPD
Definition(s)
Proactive MPD
Using MPD methods and/or equipment to actively control the pressure profile throughout the exposed wellbore. Source: IADC UBO / MPD Glossary, December 2011. Global StandardsPrimary Location Instruments
Definition(s)
Primary Location Instruments
Location where the instruments normally used to monitor flow conditions are located. Source: IADC UBO / MPD Glossary, December 2011. Global StandardsPressurized Surge Tank
Definition(s)
Pressurized Surge Tank
Also called an accumulator; prevents the transfer of pressure waves to other parts of the line or vessel system. Source: IADC UBO / MPD Glossary, December 2011. Global StandardsPressurized Mud Cap Drilling
Definition(s)
Pressurized Mud Cap Drilling
A drilling technique used to drill without returns while balancing a full annular fluid column by using a Light Annular Mud (LAM) cap maintained above an open-hole formation that is taking all injected (sacrificial) fluid and drilled cuttings assisted by surface pressure. The LAM density is chosen based on ability to make LAM and the desired surface pressure that can be maintained and observed. Periodically injecting more of the same fluid into the annulus provides a means to control the surface back-pressure within the operating limits of the RCD and/or riser system.
Source: ABS Guide for Classification and Certification of Managed Pressure Drilling Systems, September 2017. Global Standards