Oil and Gas Terms Beginning with “F” — Page 6

A fluid density log is a record of the density (or changes in density) of fluids in a producing or injection well as a function of depth — providing the foundational measurement that supports multiphase flow… Read more →

A fluid friction reducer is a high-molecular-weight polymer additive, typically a polyacrylamide or partially hydrolyzed polyacrylamide (HPAM) compound, that is added to hydraulic fracturing fluids in small… Read more →

A fluid interface log is a production logging measurement suite designed to locate, identify, and track the contacts between different fluid phases (oil/water, gas/liquid, or gas/oil/water) within the casing or tubing… Read more →

What Is a Fluid Loss Additive? Fluid loss additive (also called a filtration control additive or fluid loss control agent ) is a chemical or particulate material incorporated into a drilling fluid, cement slurry, or… Read more →

Fluid loss control in drilling and completion engineering refers to the management of filtrate invasion — the process by which liquid from the wellbore fluid (drilling mud, completion fluid, or cement slurry) migrates… Read more →

Fluid-loss control material is a category of drilling fluid additives specifically engineered to reduce the volume of filtrate (liquid phase of the drilling mud) that passes through the filter medium formed by the… Read more →

Fluoboric acid (HBF₄, tetrafluoroboric acid) is an acid stimulation fluid used in sandstone matrix acidizing as a slow-release source of hydrofluoric acid (HF). When pumped into a formation, fluoboric acid hydrolyzes… Read more →

A technique for imaging a core by moving a core between a source of X-rays and a fluorescent screen. The image on the screen is intensified and recorded by a video camera. Read more →

A flush-joint connection is a tubular pipe coupling design in which the outer diameter (OD) of the coupling is the same as the OD of the pipe body, producing a joint with no external upset or tool joint protrusion at… Read more →

A high flow rate reached with a new well. Read more →

The flushed zone in wireline logging terminology is the region of the formation immediately adjacent to the borehole wall where drilling fluid filtrate has displaced virtually all of the original formation fluid during… Read more →

Flushed zone water saturation (Sxo) is the water saturation in the portion of the formation immediately adjacent to the wellbore that has been invaded and flushed by drilling fluid filtrate during the drilling process —… Read more →

Fluvial describes a depositional environment created by rivers and running water, where current-driven transport of sand, silt, and gravel sorts grains by size and rounds them by abrasion, leaving behind sedimentary… Read more →

Magnetic flux leakage (MFL) is a non-destructive inspection technique in which a strong permanent magnet or electromagnet saturates the pipe wall with a magnetic field; where the pipe wall is locally thinned by… Read more →

The noncombustible residue from the burning of pulverized coal. Fly ash is pozzolanic and is frequently used to replace a portion of the cement and reduce its density. Read more →

Foam diversion is a stimulation technique that uses nitrogen-generated foam — a mixture of surfactant-stabilized gas bubbles dispersed in an aqueous liquid — as a temporary blocking agent to redirect acid or other… Read more →

What Is Foam Flooding? Foam flooding (also called foam-assisted EOR or foam mobility control ) is an enhanced oil recovery (EOR) or gas injection mobility control technique in which foam — a dispersion of gas bubbles… Read more →

A foam generator is a device that combines a surfactant solution with a gas (most commonly nitrogen) to produce a stable foam for injection into a well or pipeline. The generator works by forcing the liquid and gas… Read more →

What Is Foamed Cement? Foamed cement (also called nitrogen-foamed cement or low-density cement ) is a wellbore cementing system in which nitrogen gas is injected under high pressure into a cement slurry immediately… Read more →

A foaming agent in oil and gas operations is a surface-active chemical compound (surfactant) that reduces the surface tension of liquids and stabilizes the foam formed by the dispersion of gas bubbles in a liquid… Read more →

Foamy oil is a non-equilibrium, metastable mixture of heavy crude oil and dispersed solution gas that forms when reservoir pressure drops below the bubble point in heavy oil reservoirs — rather than the dissolved gas… Read more →

Fold in seismic data is a measure of the redundancy of common-midpoint (CMP) seismic data, equal to the number of offset receivers that record a given data point (or that record traces in a given common-midpoint bin)… Read more →

Variations in the properties of seismic data, encountered during processing, that are related to the acquisition geometry and distort the amplitude and phase of reflections. Also called acquisition footprint. Read more →

The amount of foreign personnel, material and services that working interest owners are permitted to employ, as defined under the terms of a concession when drilling and operating a well. Read more →

Formaldehyde (chemical formula HCHO, also called methanal or formalin when in aqueous solution) is a simple aldehyde compound used in the petroleum industry primarily as a biocide (a chemical that kills bacteria, algae,… Read more →

A formate is a class of salts produced by the neutralization of formic acid (HCOOH, the simplest carboxylic acid) with a metal hydroxide or metal oxide, with the resulting salt having the general formula HCOO-M+ (where… Read more →

Formation, in petroleum geology and stratigraphy, is the fundamental lithostratigraphic unit used to describe, classify, and map rock sequences in the subsurface and at surface outcrops, defined as a body of rock that… Read more →

What Is Formation Damage in Oil and Gas? Formation damage is any reduction in the intrinsic permeability of a reservoir rock near the wellbore caused by drilling, completion, production, or injection operations. It… Read more →

What Is Formation Evaluation? Formation evaluation (also called petrophysical evaluation or well evaluation ) is the integrated process of collecting, analyzing, and interpreting data from wireline logs,… Read more →

Formation exposure time in drilling operations is the cumulative duration that an open-hole formation remains in contact with drilling fluid between the time the drill bit first penetrates that formation and the time… Read more →