Oil and Gas Terms Beginning with “P” — Page 4

A wireline log run to provide a means of depth correlation by comparing the position of casing collars to the reference log (gamma ray log). A short casing joint generally is run near the area to be perforated to assist… Read more →

A specially prepared fluid placed in the wellbore over the interval to be perforated. The ideal fluid is clean and solids-free (filtered), and will not react to cause damaging by-products on contact with the reservoir… Read more →

A device used to perforate oil and gas wells in preparation for production. Containing several shaped explosive charges, perforating guns are available in a range of sizes and configurations. The diameter of the gun… Read more →

What Is Perforation? Perforation is the engineered communication tunnel through steel casing , cement sheath, and into the reservoir formation that establishes the primary flow path between the producing interval and… Read more →

The number of perforations per linear foot. This term is used to describe the configuration of perforating guns or the placement of perforations, and is often abbreviated to spf (shots per foot). An example would be an… Read more →

A measure, or indicator, of the length that a useable perforation tunnel extends beyond the casing or liner into the reservoir formation. In most cases, a high penetration is desirable to enable access to that part of… Read more →

The radial distribution of successive perforating charges around the gun axis. Perforating gun assemblies are commonly available in 0-, 180-, 120-, 90- and 60-degree phasing. The 0-degree phasing is generally used only… Read more →

A graphical representation of harmonic information in a data set. Often taken from Fourier analysis of the data, this representation is used to determine periodicities in petrophysical data and in geological… Read more →

The permanently frozen subsoil that lies below the upper layer (the upper several inches to feet) of soil in arctic regions. Read more →

The level to which all subsurface depths in an area are referred, normally the mean sea level. In individual wells, the depth is measured from the depth reference. However, in order to compare data between wells it is… Read more →

What Is Permanent Well Monitoring? Permanent well monitoring is the continuous, real-time acquisition of downhole pressure, temperature, flow rate, and fluid composition data through sensors permanently installed in the… Read more →

What Is Permeability? Permeability quantifies a rock's capacity to transmit fluids under a pressure gradient, governing how readily oil, gas, or water moves through interconnected pore spaces in a reservoir. Defined… Read more →

The product of formationpermeability, k, and producing formation thickness, h, in a producing well, referred to as kh. This product is the primary finding of buildup and drawdown tests and is a key factor in the flow… Read more →

An apparatus for measuring the permeability of a core sample. Measurements are made either by placing the sample in a chamber (also known as a core holder), or by placing a probe on the surface of the sample.… Read more →

Generally, the distance between a receiver and a source in a survey, such as an electromagnetic survey. In seismic surveys, perpendicular or normal offset is the component of the distance between the source and… Read more →

The resistivity of a formation measured by flowing current perpendicular to the bedding planes. In anisotropic formations, the parallel and perpendicular resistivities are different. Read more →

(noun) A production logging tool consisting of a flexible, flower-shaped metal basket that expands against the casing or tubing wall to divert all fluid flow through a central spinner or sensor, providing a full-bore… Read more →

The examination of rocks in thin section. Rock samples can be glued to a glass slide and the rock ground to 0.03-mm thickness in order to observe mineralogy and texture using a microscope. (A petrographic microscope is… Read more →

A complex mixture of naturally occurring hydrocarbon compounds found in rock. Petroleum can range from solid to gas, but the term is generally used to refer to liquid crude oil. Impurities such as sulfur, oxygen and… Read more →

Geologic components and processes necessary to generate and store hydrocarbons, including a mature source rock, migration pathway, reservoir rock, trap and seal. Appropriate relative timing of formation of these… Read more →

What Is Petroleum Systems Modeling? Petroleum systems modeling (PSM, also called basin modeling) is the quantitative simulation of the geological processes that generate, expel, migrate, and accumulate hydrocarbons over… Read more →

The study of macroscopic features of rocks, such as their occurrence, origin and history, and structure (usually by examining outcrops in the field) and their texture and composition (by studying smaller samples more… Read more →

A model of a reservoir or a field in which the petrophysical data were the only or the primary data used to construct the model. Read more →

Rock types that have been classified according to their petrophysical properties, especially properties that pertain to fluid behavior within the rock, such as porosity, capillary pressure, permeabilities, irreducible… Read more →

An interpretation of the presumed continuation of an event. In areas of discontinuous, divergent reflectors or incoherent data, drawing phantoms allows the interpreter to generate a map on a discontinuous event. Read more →

A description of the motion of, or means of comparison of, periodic waves such as seismic waves. Waves that have the same shape, symmetry and frequency and that reach maximum and minimum values simultaneously are in… Read more →

A pressure phenomenon caused in a wellbore by rise of gas and fall of liquids trapped in a wellbore after a surface shut-in. This phenomenon can cause a "hump" in the buildup curve, and frequently leads to incorrect… Read more →

The change in position of the peaks of a sinusoidal electromagnetic wave as it passes through the formation. If the sinusoidal wave picked up by two receivers a certain distance apart in a formation are compared, it is… Read more →

The ability of the formation to resist electrical conduction, as derived from the change in position of the peaks of an electromagnetic wave generated in a propagation resistivity measurement. At the frequencies used,… Read more →

A record of the velocity with which a particular phase (gas, oil or water) moves in a producing well. While most flowmeters measure some average of all the fluids, the phase-velocity log identifies one particular phase.… Read more →