Oil and Gas Terms Beginning with “T”

T1 is the longitudinal (spin-lattice) relaxation time in nuclear magnetic resonance (NMR) measurements — the characteristic time constant describing how rapidly hydrogen protons in a formation fluid (formation water,… Read more →

T2 in nuclear magnetic resonance (NMR) well logging is the transverse relaxation time — the time constant characterizing how quickly the coherent precession of hydrogen proton spins in the formation dephases after… Read more →

A thermally activated mud emulsion is a water-based drilling fluid that uses cloud-point glycol as a shale inhibitor. Cloud-point glycol is a water-soluble polymer that dissolves clearly in water at surface temperatures… Read more →

Abbreviation for Trans-Alaska Pipeline System Read more →

True amplitude recovery (TAR) is a sequence of seismic data processing steps designed to compensate for the amplitude decay of seismic waves caused by spherical divergence, intrinsic attenuation (anelastic absorption),… Read more →

Tubing-conveyed perforating (TCP) is a perforating technique that uses tubing (production tubing, drillpipe, or coiled tubing) rather than wireline to convey perforating guns to the required depth in the wellbore —… Read more →

The planned end of the well, measured by the length of pipe required to reach the bottom. Read more →

TE (transverse electric mode) in the context of oil and gas well logging refers to the transverse electric propagation mode in electromagnetic (EM) induction and propagation resistivity tools — an electromagnetic wave… Read more →

Abbreviaton for technical evaluation agreement. Read more →

The transient electromagnetic method (TEM), also called time-domain electromagnetic (TDEM) surveying, is a geophysical technique that measures the secondary electromagnetic fields induced in the earth by a primary… Read more →

(noun) Abbreviation for Thermally Enhanced Oil Recovery. A category of enhanced oil recovery methods that use heat to reduce crude oil viscosity and improve flow characteristics within the reservoir. TEOR techniques… Read more →

An abbreviation on drilling reports or mud logs signifying trip for new bit. Read more →

TG in oilfield technical usage is an abbreviation that appears in several contexts, most commonly as the abbreviation for temperature gradient — the rate of temperature increase with depth in a wellbore or formation,… Read more →

Abbreviation for toe to heel air injection. Read more →

The transverse magnetic (TM) mode is a specific configuration of an electromagnetic field in which only one component of the magnetic field exists alongside two components of the electric field perpendicular to it — for… Read more →

TOC, or total organic carbon, is the mass fraction of organic carbon in a rock sample expressed as weight percent, measured by combustion or Rock-Eval pyrolysis, and used as the primary indicator of a sedimentary rock's… Read more →

What Is TVD? TVD is the abbreviation for true vertical depth, the vertical distance measured from a surface reference datum (typically the kelly bushing or mean sea level) to a specific point in a wellbore, computed… Read more →

TWT, two-way traveltime, is the total elapsed time for a seismic wave to travel down from its source at the surface to a subsurface reflector and back up to a receiver, and it is the fundamental measurement axis of all… Read more →

The Taitel-Dukler flow regime map is a theoretically derived framework published in 1976 that predicts transitions between stratified, wavy-stratified, slug, annular, and dispersed bubble flow regimes in horizontal and… Read more →

Taylor bubbles are large, elongated gas bubbles that occupy most of the cross-sectional area of a pipe and travel upward through a liquid-filled vertical or near-vertical tube at a characteristic velocity determined by… Read more →

A portable mast that can be erected as a unit, with the upper section nested inside the lower section and raised by wireline or hydraulic system. Read more →

A Texas deck (also called a Texas floor, substructure deck, or catwalk deck in some regional usages) is the elevated working platform or secondary floor on a drilling rig that is positioned below the main drill floor… Read more →

What Is a Top Drive? Top drive systems are electric or hydraulic motor assemblies mounted at the top of a drilling mast that rotate the drillstring directly, replacing the conventional kelly and rotary table. Installed… Read more →

A legal document recorded each shift that includes employees' time and records different drilling information required by the oil company and regulatory bodies. Read more →

The Trans-Alaska Pipeline System (TAPS) is an 800-mile (1,287-km) crude oil pipeline stretching from Deadhorse on the North Slope of Alaska to the ice-free port of Valdez on Prince William Sound. The pipeline is 48… Read more →

What Is a Travelling Block? The travelling block is the movable pulley assembly in a drilling rig's hoisting system that moves vertically inside the derrick or mast, carrying the hook, swivel, and full weight of the… Read more →

What Is Production Tubing? Production tubing is the small-diameter steel pipe string run inside the casing of a producing oil or gas well that serves as the primary conduit for reservoir fluids — oil, gas, and water —… Read more →

Any kind of pipe used in oilfield operations including tubing, casing, drill pipe, drill collars, and heavy-weight drill pipe. Read more →

A winching machine that hoists or pulls when a cable winds around a revolving drum. Also called a winch. Read more →

To tag, in oilfield usage, is to make deliberate physical contact with a known reference point or obstruction in the wellbore using the tubing string, wireline, coiled tubing, or other intervention equipment, so that… Read more →