Oil and Gas Terms Beginning with “F”

The frequency domain is a mathematical representation of a signal in which the independent variable is frequency (measured in hertz) rather than time. Any time-domain signal (such as a seismic trace showing amplitude… Read more →

An iterative computer algorithm to perform the Fourier transform of digitized waveforms rapidly. Read more →

FT (formation tester) is a generic abbreviation in petroleum engineering referring to downhole tools and test systems that are conveyed into a wellbore to measure in-situ reservoir pressure, collect representative fluid… Read more →

A method for obtaining quantitative mineralogical analysis of a rock sample by measuring the effect of midrange infrared radiation transmitted through the sample. Read more →

A free water knockout (FWKO) is a surface production vessel designed to separate the bulk of free water from a produced crude oil and water mixture before the stream enters the main oil treater or emulsion treater,… Read more →

Fermat's principle, as applied in seismic exploration, states that seismic waves travel between two points along the path that takes the least time (or more precisely, along a stationary path where small perturbations… Read more →

Primarily used as a safety measure to prevent the accumulation of gases that could pose a hazard. Also used to manage small volumes of waste gas. Read more →

Fourier analysis is a mathematical framework for decomposing a complex signal into a sum of sinusoidal components of different frequencies, amplitudes, and phases, revealing the frequency content of signals measured in… Read more →

The process of reconstructing a function of time or space from its sinusoidal components determined in Fourier analysis. Read more →

What Is the Fourier Transform? The Fourier transform decomposes a time-domain signal — such as a seismic trace or a well log curve — into its constituent frequency components, expressing it as a spectrum of amplitudes… Read more →

Fourier Transform Infrared Spectroscopy (FTIR) is an analytical technique that measures the absorption of infrared radiation by molecular bonds in a sample to identify and quantify chemical compounds. Each type of… Read more →

What Is a Frac Plug? A frac plug is a downhole isolation tool run on wireline or coiled tubing into the casing of a horizontal well and set to create a pressure-tight seal that isolates previously completed fracture… Read more →

The Fresnel zone in reflection seismology is the area on a reflecting horizon that contributes constructively to a single seismic reflection amplitude recorded at the surface — determined by the principle that seismic… Read more →

A single-vessel technique of acquiring marineseismic data at a complete range of azimuths by towing streamers in a circular path. Read more →

The use of frequency (abbreviated as f) and wavenumber (k, the reciprocal of wavelength) as the reference framework, obtained by using the Fourier transform over time and space. Read more →

A graphical technique to distinguish subsets of data according to their direction and velocity by plotting and contouring frequency and wavenumber. Read more →

Facies in petroleum geology refers to a body of rock or sediment characterized by a specific combination of lithological, mineralogical, textural, and biological attributes that reflect the depositional environment in… Read more →

What Is Facies Modeling? Facies modeling (also called lithofacies modeling or geological facies simulation ) is the process of constructing a three-dimensional numerical model that represents the spatial distribution of… Read more →

Fairway, in petroleum geology and exploration, refers to a geographic zone or corridor within a sedimentary basin where the combination of source rock maturity, migration pathways, reservoir quality, and trapping… Read more →

What Is a Falloff Test? Falloff test (also called an injection well pressure falloff test or injectivity falloff test ) is a pressure transient test conducted on an injection well by shutting the well in after a period… Read more →

Fan shooting is a seismic refraction technique used in early oil exploration, primarily from the 1920s through the 1950s, in which a set of geophones is laid out in a fan-shaped array around a single shot point (or… Read more →

Water that is far from the clay surface, as distinct from clay-bound water (or "near" water). The term is used in the dual-water model. It includes the capillary-bound water and the free water. Read more →

The party that acquires the rights to drill and earn an assignment of the leasehold interest, receiving a farm-in. Read more →

The party that originally owns the leasehold interest and assigns the farmout. Read more →

A farmout is a contractual arrangement in which the owner of a working interest in an oil or gas lease or licence (the farmor) assigns part or all of that interest to another party (the farmee) in exchange for the… Read more →

An iterative computer algorithm to perform the Fourier transform of digitized waveforms rapidly. Read more →

Fast diffusion in petroleum reservoir engineering and NMR (nuclear magnetic resonance) logging refers to the mass transport regime in which fluid molecules move rapidly enough through the connected pore space of a rock… Read more →

A fast formation in borehole acoustic logging terminology refers to a subsurface rock formation whose compressional wave velocity (P-wave velocity) is greater than the compressional velocity of the borehole fluid… Read more →

Fast-formation arrival is a measurement artifact in acoustic logging in which the compressional wave traveling through the formation (the P-wave headwave) arrives at the tool's receivers before the direct wave traveling… Read more →

A fast neutron reaction in nuclear well logging refers to the interaction between high-energy neutrons (fast neutrons, with kinetic energies above approximately 0.5 MeV) and atomic nuclei in the formation, producing… Read more →