Ramping

Ramping

Definition(s)

Ramping

  1. Gradual startup or shutdown of a pump unit.
  2. Modeling term meaning to change variables with time.
Source: IADC UBO / MPD Glossary, December 2011. Global Standards
Purge

Purge

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 Standards
Pump Unit Shutdown

Pump 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 Standards
Pump Station

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

Pump 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 Standards
Pump Curve

Pump 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 Standards
Pump Capacity

Pump 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 Standards
Pressure Vessel –Phase Separation

Pressure 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 Standards
Process Disturbances

Process Disturbances

Definition(s)

Process Disturbances

Things that change the steady state of a control system profile.
  1. Horizontal line that indicates changes in ground elevation along the line or vessel route.
  2. Modeling term used to define changes with respect to time.
Source: IADC UBO / MPD Glossary, December 2011. Global Standards
Proactive MPD

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 Standards
Pressurized Surge Tank

Pressurized 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 Standards
Pressurized Mud Cap Drilling

Pressurized 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

Pressurized Mud Cap Drilling

Variation of MPD, drilling with no returns to surface where an annulus fluid column, assisted by surface pressure, is maintained above a formation that is capable of accepting fluid and cuttings. A sacrificial fluid with cuttings is accepted by the loss circulation zone. Useful for cases of severe loss circulation that preclude the use of conventional wellbore construction techniques. Source: IADC UBO / MPD Glossary, December 2011. Global Standards
Pressure Transient

Pressure Transient

Definition(s)

Pressure Transient

Pressure waves, traveling through the pipes at the wave speed of the fluid and caused by changes in the operation of the system. Source: IADC UBO / MPD Glossary, December 2011. Global Standards
Pressure Loss

Pressure Loss

Definition(s)

Pressure Loss

Rate of decrease in pressure along the flowing line or vessel (P f) due to friction of the fluid against the pipe wall. Source: IADC UBO / MPD Glossary, December 2011. Global Standards
Pressure Deployment

Pressure Deployment

Definition(s)

Pressure Deployment

Process of deploying or recovering drill string or coiled tubing components from a live or pressurized well. Source: IADC UBO / MPD Glossary, December 2011. Global Standards
Pressure Control Valve (PCV)

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 Standards
Pressure Control

Pressure 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 Standards
Predictive Model

Predictive 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 Standards