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

A fixed choke, also called a positive choke or a bean choke, is the simplest production-control device installed at the wellhead or on a surface flowline to restrict and meter the flow of hydrocarbons from a well by… Read more →

The fixed-source method is a controlled-source electromagnetic (CSEM) acquisition technique in which the transmitting energy source is held in a single position while the receivers, detectors, or sensors are… Read more →

A flag in oilfield operations is a physical marker -- typically a strip of colored cloth, tape, or rubber -- tied or clamped to a sand line, wireline, slickline, tubing joint, or similar running string at a specific… Read more →

A flag joint is a deliberately placed reference piece of casing or tubing inserted at a known position in a wellbore string so that downhole logging tools can re-establish their depth measurement with unambiguous… Read more →

Flake lost-circulation material (flake LCM) is a specific type of LCM particle characterized by its thin, flat physical shape with substantial surface area relative to particle volume — providing the bridging capability… Read more →

Flake lost-circulation material (flake LCM) is a specific type of LCM particle characterized by its thin, flat physical shape with substantial surface area relative to particle volume — providing the bridging capability… Read more →

A flange is a projecting rim, collar, or rib on a pipe, valve, fitting, or equipment component that provides a flat mating surface with bolt holes through which bolts and nuts clamp two flanges face-to-face to create a… Read more →

To finish an operation or process (slang). Read more →

A flapper valve is a spring-loaded, hinged disk closure mechanism used in subsurface safety valves, float equipment (float shoe and float collar for cementing), and downhole flow control applications — consisting of a… Read more →

A flare is an engineered arrangement of a vertical stack, a pilot, and one or more burner tips used to safely combust hydrocarbon vapours that cannot be conserved, sold, or otherwise routed to a sales line. Flares… Read more →

What Is Flare Gas? Flare gas (also called flared gas or vent gas) is natural gas or hydrocarbon vapor that is burned in a flare stack at the surface rather than being captured, sold, or reinjected, either because of… Read more →

Flash point is the minimum temperature at which a liquid (or liquid mixture) produces sufficient vapor to form a momentarily ignitable mixture with air at its surface when an ignition source is applied — at temperatures… Read more →

Flat gels is the condition in which the 10-second gel strength and the 10-minute gel strength of a drilling mud have similar values, indicating that the three-dimensional gel structure of the mud forms rapidly and… Read more →

A flattened section is a seismic display where one specific reflector has been stretched and squeezed until it appears as a perfectly horizontal line across the screen. Every other reflector above and below it is… Read more →

The flexural mode is a dispersive guided acoustic wave that propagates along the borehole by bending the borehole wall in a dipole (two-lobed) pattern, generated by dipole transmitters oriented perpendicular to the… Read more →

What Is a Float Collar? A float collar is a short casing sub installed 1 to 2 joints above the guide shoe at the bottom of a casing string, containing an internal check valve that permits cement slurry to be pumped… Read more →

A float joint is a short casing or liner joint, typically 2 to 5 feet in length, installed in a casing string just above the float shoe at the bottom of the string, housing the float collar that contains a spring-loaded… Read more →

What Is a Float Shoe? Float shoe (also called a guide shoe with float) is a downhole tool installed at the bottom of a casing string that combines two distinct functions: a guide shoe with a beveled or rounded nose that… Read more →

A floc is a coagulated mass of particles in a liquid. Individual particles in a stable suspension repel each other and remain dispersed; particles in a flocculated suspension stick together into larger aggregates that… Read more →

A flocculant in oilfield applications is a chemical that causes a dispersed colloidal system, such as clay particles suspended in drilling mud or produced water, to destabilize and aggregate into larger clusters called… Read more →

Flocculation is the aggregation of fine colloidal or suspended particles into larger, loosely bound clusters (flocs) as a result of reduction or neutralization of the electrostatic repulsive forces that normally keep… Read more →

A flooding surface in sequence stratigraphy is a sedimentary surface that exhibits evidence of an abrupt increase in water depth, separating younger strata above from older strata below — typically formed in response to… Read more →

A flow after flow test (also called a back-pressure test or multi-rate deliverability test) is a well productivity evaluation procedure in which a gas or oil well is produced at a series of successively increasing or… Read more →

The process of allowing fluids to flow from the well following a treatment, either in preparation for a subsequent phase of treatment or in preparation for cleanup and returning the well to production. Read more →

A flow check is a brief, deliberate pause in drilling, tripping, or well-servicing operations during which the rig crew shuts down circulation and observes the well at the flowline or trip tank to verify that the… Read more →

A flow coupling in oil and gas well completions is a short sub placed in the production tubing string at a specific depth to create a controlled turbulent flow region around the tubing that prevents erosion damage to… Read more →

What Is Flow Efficiency? Flow efficiency (also called FE or completion efficiency ) is a dimensionless ratio used in well test analysis that compares the actual productivity index of a well to the ideal productivity… Read more →

A surface pipeline carrying oil, gas or water that connects the wellhead to a manifold or to production facilities, such as heater-treaters and separators. Read more →

What Is a Flow Loop? A flow loop circulates fluids continuously through a closed pipe circuit so engineers can study multiphase flow behaviour and calibrate production logging tools under controlled conditions.… Read more →

A flow model is a computational representation of a reservoir in which the steady-state flow and the advective transport (the bulk movement of fluids through the reservoir) are described in two or three spatial… Read more →