Oil and Gas Terms Beginning with “R” — Page 2

A classification of blowout preventer in which the pressure-control functions are achieved through the operation of hydraulically operated ram sets. Each ram set is configured as an opposing pair and, depending on… Read more →

A nonreproducible error that is generally imputable to the physics of the measurement. For example, the statistical errors in nuclear measurements are random errors. Read more →

Disturbances in seismic data that are not coherent (they lack a phase relationship between adjacent traces, unlike air waves and ground roll) and cannot be correlated to the seismic energy source. Random noise can be… Read more →

A method of performing stochastic analysis on dynamic data. This method can be used in stochastic simulation of fluid behavior in reservoirs and fields. Read more →

The difference between the maximum load reached in the upstroke and the minimum load registered in the downstroke. Read more →

A dilatation, or decrease in pressure and density of a medium as molecules are displaced by a P-wave. As P-waves pass through the Earth, the Earth undergoes compression and expansion. These changes in volume contribute… Read more →

(noun) A component of the total skin factor in a well that increases with flow rate, caused by non-Darcy (turbulent or inertial) flow in the near-wellbore region, particularly in high-rate gas wells. The rate-dependent… Read more →

Extra hole drilled at the bottom of the hole to leave expendable completion equipment, such as the carriers for perforating gun charges. Read more →

Crude oil direct from the wellbore, before it is treated in a gas separation plant. It usually contains nonhydrocarbon contaminants. Read more →

Gas coming directly from the wellbore containing nonhydrocarbon contaminants and hydrocarbons that can be liquefied. Read more →

A technique for predicting or determining arrival times of waves at detectors using raypaths. Ray tracing requires a velocity model and the assumption that rays behave according to Snell's law. Ray tracing provides the… Read more →

The path or direction along which wave energy propagates through the Earth. In isotropic media, the raypath is perpendicular to the local wavefront. The raypath can be calculated using ray tracing. Seismic energy… Read more →

With reference to measurements-while-drilling (MWD), the data transmitted to surface shortly after being recorded. These are distinct from the recorded data. Only a subset of the recorded data can be transmitted as… Read more →

To enlarge a wellbore. Reaming may be necessary for several reasons. Perhaps the most common reason for reaming a section of a hole is that the hole was not drilled as large as it should have been at the outset. This… Read more →

A device that detects seismic energy in the form of ground motion or a pressure wave in fluid and transforms it to an electrical impulse. Read more →

To alternately raise and lower the drillstring, casing string or liner in the wellbore. Reciprocation is usually limited to 30 to 60 ft [9 to 18 m] of vertical travel in the derrick. The purpose of reciprocating the… Read more →

A type of fluid pump in which reciprocating pistons or plungers displace the fluid. Read more →

A type of mixer used in various oil- and gas-well service activities to prepare treatment fluids or slurries. Recirculating mixers are configured with a tank or vessel, a pump to circulate the fluid, and a manifold… Read more →

(verb) To detect, measure, and store geophysical or well data using electronic instruments for subsequent processing and interpretation. In seismic acquisition, recording involves capturing the electrical signals… Read more →

With reference to measurements-while-drilling (MWD), the data recorded by the logging tools and stored in a downhole electronic memory. These data are subsequently retrieved when the tools are brought to surface.… Read more →

(noun) A downhole or surface instrument that records physical measurements such as pressure, temperature, flow rate, or depth over time during well testing, production logging, or reservoir monitoring operations. Modern… Read more →

A downhole tool used to locate or convey a downhole gauge. Recorder carriers may be incorporated into temporary completions, such as for testing purposes, or run on slickline for temporary placement within the wellbore.… Read more →

Injection gas that has returned to surface and it is not reinjected into the gas-lift system. Instead, it is transferred to a pipeline. This gas is sometimes called spent gas-lift gas. Read more →

The fraction of hydrocarbons that can or has been produced from a well, reservoir or field; also, the fluid that has been produced. Read more →

What Is Recovery Factor in Oil and Gas? The recovery factor is the fraction of original oil in place (OOIP) or original gas in place (OGIP) that is ultimately recovered through all production methods over the economic… Read more →

A prediction of the amount of production that will occur from a well, reservoir or field. This estimate is sometimes expressed as a fraction of the total hydrocarbons originally in place Read more →

A clay-based water mud that used tannates (from tannic acid) as clay deflocculant and mined lignite for fluid-loss control, usually with lime. The tannates were usually quebracho, which is red at high pH. Red muds were… Read more →

A contraction of reduction-oxidation, a type of chemical reaction in which one reactant is reduced (gains electrons) while the other is oxidized (loses electrons). Examples of redox mud chemistry are: (1) sulfite anions… Read more →

A cementslurry made with less mix water than is customarily used without modifying additives. Read more →

A cementslurry made with less mix water than is customarily used without modifying additives. Read more →