Oil and Gas Terms Beginning with “T” — Page 5

Tongs in drilling rig operations are large-capacity self-locking wrenches used to grip drillstring components (drillpipe, drill collars, casing) and apply rotational torque for connection makeup (tightening) and… Read more →

A tool joint is the forged-steel threaded connector welded onto each end of a drill pipe tube to form the male pin and female box connections that link individual pipe joints into a continuous drill string,… Read more →

(noun) An assembly of multiple downhole tools connected end-to-end and run into the wellbore on wireline, coiled tubing, or drillpipe to perform a specific operation such as production logging, perforating, or fishing.… Read more →

A toolpusher is the rig location supervisor for the drilling contractor who manages the day-to-day operations of the drilling rig and serves as the senior operational decision-maker on the rig site — providing the… Read more →

A top lease is an oil and gas lease taken on a tract of land that is already subject to an existing, unexpired lease, with the new lease drafted so that it becomes effective only upon the expiration or termination of… Read more →

The top log interval in well logging operations is the uppermost depth section recorded on a particular logging run, defined by the shallowest depth at which the logging tool begins recording data as it is pulled upward… Read more →

What Is a Top Drive? A top drive suspends from the traveling block and rotates the drill string from the top of the stand using an electrically or hydraulically powered motor, eliminating the need for a kelly and rotary… Read more →

A topographic map is a contour map that portrays the elevation of the Earth's surface, using contour lines to connect points of equal elevation above a vertical datum, most commonly mean sea level. Each contour line… Read more →

A tornado chart is a graphical interpretation tool used in resistivity log interpretation that displays the effect of mud filtrate invasion on resistivity measurements with different depths of investigation, providing… Read more →

In wireline logging a torpedo is the connection between the wireline logging cable and the bridle, the short specialized cable section that links the main armored line to the head of the logging toolstring. The torpedo… Read more →

A torque flowmeter (also called a turbine flowmeter with torque measurement, a torque-type flow sensor, or a gyroscopic flowmeter in some contexts) is a flow measurement device that determines the volumetric or mass… Read more →

Total depth, almost always abbreviated TD, is the bottom of a particular hole section, the point at which drilling is stopped so that logs can be run and casing set and cemented before a smaller-diameter section is… Read more →

A total hardness test is a chemical analysis performed on water, drilling fluid filtrate, or produced water to measure the combined concentration of calcium and magnesium ions (both divalent cations that cause water… Read more →

Total organic carbon (TOC) is the primary geochemical measure of organic richness in potential source rocks and unconventional shale reservoirs, expressed as the weight percent of organic carbon in a dry rock sample,… Read more →

Total porosity is the fraction of a rock's bulk volume that consists of void space — pores, fractures, vugs, and all other open spaces regardless of whether they are connected to each other or to the wellbore —… Read more →

In the oilfield, a tour (pronounced "tower," rhyming with "power," not with the tourist destination) is a scheduled work shift on a drilling rig, production platform, or other continuous-operations facility, typically… Read more →

In well logging and petroleum data presentation, a trace is the graphical representation of a single log measurement plotted against depth, displayed as a continuous line that runs vertically down a printed or digital… Read more →

Tracer measurement is an oilfield technique in which small quantities of chemical, radioactive, or stable-isotope tracers are injected into a wellbore or reservoir to track fluid movement, quantify flow contributions… Read more →

(noun) A production logging technique in which a radioactive or chemical tracer is ejected from a tool into the wellbore fluid stream and detected by sensors positioned above or below the ejection point to determine the… Read more →

What Is a Tracer-Loss Measurement? A tracer-loss measurement quantifies the volume and rate of drilling fluid filtrate or mud that invades the formation by adding a chemical tracer at known concentration to the mud and… Read more →

A track in well log presentation is a vertical section of the log display dedicated to a particular set of data curves or annotation columns, dividing the printed or digital log into multiple parallel vertical channels… Read more →

A transform fault is a strike-slip fault that forms an active boundary between two tectonic plates. Unlike normal faults, where plates pull apart, or thrust faults, where one plate rides over another, a transform fault… Read more →

A transgression is the landward migration of a shoreline as relative sea level rises faster than sediment can fill the available space, flooding former coastal and continental areas and producing a retrogradational… Read more →

A transgressive surface is the marine flooding surface that separates the underlying lowstand systems tract from the overlying transgressive systems tract, and in most sequence-stratigraphic frameworks it represents the… Read more →

(noun) The radial distance from a wellbore to which a pressure disturbance has propagated during a well test before reaching a reservoir boundary or achieving pseudo-steady-state conditions. The transient drainage… 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 →

The change in pressure with time. In well testing, this refers to the pressure measured as a function of time after the test is initiated. Read more →

Transient pressure response in reservoir engineering and well test analysis refers to the time-varying pressure behavior measured at or near the wellbore following a change in well flow rate, where the pressure wave… Read more →

Transient pressure testing in oil and gas reservoir engineering is the systematic field procedure of recording wellbore pressure as a function of time following a controlled change in well production rate, injection… Read more →

Transient rate and pressure test analysis (also called rate-transient analysis, RTA, or production data analysis) is a reservoir engineering discipline that uses simultaneously measured production rate and flowing… Read more →