Latest Posts

Definition(s)

---

Rupture disc

Device that relieves pressure when an absolute pressure value is high enough to rupture the disc material, thus allowing fluid to flow into some type of a vessel. Source: IADC UBO / MPD Glossary, December 2011. Global Standards

Definition(s)

---

Roughness

Measure of the surface condition of the internal wall of pipe; Roughness can change with the age of the pipe and the type of service it has provided. Source: IADC UBO / MPD Glossary, December 2011. Global Standards

Definition(s)

---

Rotating Blowout Preventer

(Rotating annular preventer designed to rotate with pipe and seal on both pipe and kelly while allowing upward and downward movement of the pipe – also known as RBOP) Design specific to underbalance drilling. Models available for both top drive and Kelly drive applications. Source: IADC UBO / MPD Glossary, December 2011. Global Standards

Definition(s)

---

Rotating Diverter

Generic term, - sometimes used to mean rotating head, or rotating blowout preventer. Source: IADC UBO / MPD Glossary, December 2011. Global Standards

Definition(s)

---

Rotary Motion Valve

Valve whose closure member rotates opening or closing rotating equipment, centrifugal pumps, or compressors. Source: IADC UBO / MPD Glossary, December 2011. Global Standards

Definition(s)

---

Rising Characteristic Curve

Preferred curve shape for pump H-Q curves; this curve has a steady increase of H with decreasing Q. Source: IADC UBO / MPD Glossary, December 2011. Global Standards

Definition(s)

---

Reynolds Number

Mathematical relationship that describes the interdependence between the pipe diameter, fluid viscosity, and flow velocity; a dimensionless number used to describe the type of flow exhibited by a fluid flowing through a pipe. Source: IADC UBO / MPD Glossary, December 2011. Global Standards

Definition(s)

---

Return System

Handles returns from the well – injected fluids, (gas and liquid) cuttings, hydrocarbons, formation water etc. Consists of flow diverter, flow cross, emergency shut down valve, choke manifold, pressure vessel and solids control equipment, from where the liquid phase used for drilling is passed on to the drilling fluid tank, and then to the rig pumps for re injection to the well. Source: IADC UBO / MPD Glossary, December 2011. Global Standards

Definition(s)

---

Report by Exception

RTU sends information to the Host when data has changed by a specified amount. Source: IADC UBO / MPD Glossary, December 2011. Global Standards

Definition(s)

---

Remote Terminal Unit (RTU)

Computer located at a remote location that gathers the information provided by all the PLCs at the location, and transmits that information back to the host computer. Source: IADC UBO / MPD Glossary, December 2011. Global Standards

Definition(s)

---

Remote Station

Auxiliary controls for operating a blowout preventer. Source: IADC UBO / MPD Glossary, December 2011. Global Standards

Definition(s)

---

Remote Choke Panel

A set of controls, usually placed on the rig floor, used to control the amount of fluid circulated out through the choke manifold. Source: IADC UBO / MPD Glossary, December 2011. Global Standards

Definition(s)

---

Relative Roughness

Ratio of the absolute roughness of the inside pipe wall to the internal diameter of the pipe; Absolute roughness is the average height of imperfections in the pipe wall surface. Source: IADC UBO / MPD Glossary, December 2011. Global Standards

Definition(s)

---

Reid Vapor Pressure

A test method to determine the vapor pressure of volatile petroleum liquids at 100° F with an initial boiling point above 32° F. (ASTM D 323) Source: IADC UBO / MPD Glossary, December 2011. Global Standards

Definition(s)

---

Reference Level

Zero elevation/head on a total energy diagram. For line or vessel applications, the reference level is usually sea level. Source: IADC UBO / MPD Glossary, December 2011. Global Standards

Definition(s)

---

Recycle Line

Gas line that allows re-circulation of discharge gas into the suction side of a centrifugal compressor; this permits a centrifugal compressor to be placed on-line or off-line in parallel with other units without creating a surge condition. Source: IADC UBO / MPD Glossary, December 2011. Global Standards

Definition(s)

---

Recoverable Energy

Head below the total headline; energy which is still useful for moving oil down the line or vessel. Source: IADC UBO / MPD Glossary, December 2011. Global Standards

Definition(s)

---

Reciprocating Compressor

1. a piston-type positive displacement compressor which increases the pressure of a definite volume of gas by reducing the cylinder volume, resulting in a pulsating delivery of gas;
2. any compressor which employs a piston working inside a cylinder to compress a gas; usually has "pockets" that allow for limited pressure and flow control.

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

Definition(s)

---

Real-time Model

Uses SCADA data to run in lock step with the actual line or vessel. The goal is for calculated flows and pressures to track telemetered points, with consistent and reasonable accuracy, so that confidence can be gained in the model's ability to predict future operating conditions, as well as estimate conditions at non-telemetered locations. Source: IADC UBO / MPD Glossary, December 2011. Global Standards

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 Standards

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 Standards

Definition(s)

---

Rankine

(degrees temperature) - English measurement of absolute temperature (+459.69 offset). Source: IADC UBO / MPD Glossary, December 2011. Global Standards