Oil and Gas Terms Beginning with “T” — Page 2

The tail is the last page or pages of a wireline or logging-while-drilling print, the section appended at the end of the curve display that carries the supporting information about the well, the recording parameters,… Read more →

A tail buoy in marine seismic acquisition is a buoyant float attached to the trailing end of each seismic streamer cable deployed behind a seismic survey vessel, serving the critical functions of marking the end… Read more →

Tail cement is the last (and typically densest) cement slurry pumped during a primary cementing job, designed to occupy the deepest portion of the annulus around the casing string and to provide a strong,… Read more →

A tail mute is a processing operation applied to seismic reflection data that zeroes out, or "mutes," a region of each shot or common-midpoint gather defined by a cutoff in record time, source-to-receiver offset, or… Read more →

A tail pipe in petroleum completion and production engineering is a length of tubing or pipe attached below a downhole pump, packer, or completion assembly and extending downward into the well to improve fluid intake… Read more →

Tally refers to the running record of tubular goods on a drilling or workover rig, where each joint of drill pipe , tubing, or casing is individually measured, numbered, and tracked as it is run into or pulled out of… Read more →

(noun) A graphical method used in directional drilling to plot the wellbore trajectory by assuming a straight-line path between successive survey stations at the inclination and azimuth measured at the lower station.… Read more →

A tank is a metal or plastic vessel used to store or measure a liquid, and it is among the most ubiquitous pieces of surface equipment in the oil and gas industry, appearing at every stage from the drilling rig to the… Read more →

A tank battery is a group of surface storage tanks that receives crude oil production from one or more wells on a producing lease. The tanks hold the produced oil after it has been separated from gas and water, before… Read more →

Tank bottoms in the petroleum industry are the accumulated mixture of water, sediment, rust, scale, wax, asphaltenes, emulsified oil, and other solid and semi-solid contaminants that settle to the bottom of crude oil… Read more →

(noun) The process of determining the relationship between liquid level and contained volume in a storage tank through physical measurement (strapping), optical methods, or liquid calibration techniques. Tank… Read more →

A tank dike, also called a firewall, berm, or secondary containment structure, is an earthen, concrete, or engineered barrier constructed around one or more aboveground storage tanks (ASTs) at oil and gas production… Read more →

A tank table is a calibration chart that gives the liquid capacity of a storage tank, expressed in barrels or cubic metres, as a function of the liquid level measured inside the tank. It is also called a tank capacity… Read more →

The capacity of all the tanks in a field Read more →

A tanker in the oil and gas industry is a specialized cargo vessel designed and built to transport liquid petroleum products (crude oil, refined products including gasoline, diesel, fuel oil, and jet fuel, or liquefied… Read more →

The acids found in tannin. Quebracho contains tannic acid. Read more →

Tannin is a class of naturally occurring, moderate molecular weight anionic polymers extracted from tree bark and woody plants, used in water-based drilling fluids as a clay deflocculant, or thinner, to control… Read more →

A taper tap is a downhole fishing tool used to engage the internal diameter (ID) of a hollow fish (such as drill pipe, drill collars, or tubing) that is stuck in the wellbore, by means of a tapered external thread… Read more →

What Is a Tapered Cutoff? A tapered cutoff is a gradual rather than sharp T2 threshold used in nuclear magnetic resonance (NMR) log interpretation to partition bound from free water, assigning a progressively smaller… Read more →

A tapered string is a wellbore tubular assembly — either a casing string, production tubing string, or drill string — composed of multiple sections of different outside diameters, wall thicknesses, or steel grades… Read more →

Tar sand — more accurately and commonly called oil sand or bituminous sand in the industry — is a naturally occurring mixture of sand or sandstone, clay minerals, water, and bitumen (an extremely dense, viscous form of… Read more →

A technical evaluation agreement, commonly abbreviated TEA, is a short-term contract between a host country, usually acting through its national oil company or petroleum ministry, and an operator that grants the… Read more →

A tectonic environment is the location of a region relative to the boundary of a tectonic plate, particularly a boundary along which plate-tectonic activity is occurring or has occurred, and it is the single most… Read more →

(noun) The large-scale deformation of the Earth's crust driven by plate tectonic forces, including folding, faulting, uplift, and subsidence. Tectonism creates the structural traps, migration pathways, and basin… Read more →

Telemetry in drilling and well operations is the technology and systems used to transmit real-time data from downhole tools and instruments to the surface during drilling, completion, or production operations —… Read more →

A tell-tale is a simple but indispensable mechanical indicator used to confirm the position or function of a downhole or surface component that the operator cannot see directly, and in cementing operations its most… Read more →

A telluric current (from the Latin tellus, meaning Earth) is a naturally occurring, low-frequency electrical current that flows through large volumes of the Earth's crust and upper mantle, driven primarily by… Read more →

The telluric current method is an electromagnetic geophysical exploration technique that measures naturally occurring low-frequency electric currents flowing in the Earth's crust (telluric currents, generated by… Read more →

What Is a Temperature Log? A temperature log is a continuous wellbore measurement that records formation temperature as a function of depth using a sensitive resistance thermometer or thermocouple sensor on a wireline… Read more →

Temperature stability is the characteristic of a drilling fluid, or of an individual mud product, that describes its response to prolonged heating, and it is one of the controlling design criteria for any deep or… Read more →