Oil & Gas Terms in Category T

Telescoping derrick

A portable mast that an be erected as a unit, usually by a tackle that hoists the wireline or by hydraulic pistons.

The upper section of a telescoping derrick is generally nested (telescoped) inside the lower section of the structure and raised to full height either by the wireline or by a hydraulic system.

Thief zone

See thief formation

Tool hand

The tool man; a packer hand; a service company hand.

Turnkey contract

A drilling contract that calls for the payment of a stipulated amount to the drilling contractor on completion of the well.

In a turnkey contract, the contractor furnishes all material and labor and controls the entire drilling operation, independent of operator supervision.

A turnkey contract does not, as a rule, include the completion of a well as a producer.


The operation of hoisting the drill stem out of and returning it to the wellbore.

See make a trip.

Turbulent flow

The erratic, nonlinear flow of a fluid, caused by high velocity.

Characterized by random eddying flow patterns superimposed on the general flow progressing in a given direction.

Tail out rods

To pull the bottom end of a sucker rod away from a well when laying rods down.


Abbreviation: temporarily abandoned.

Tubingless completion

A method of producing a well in which only production casing is set through the pay zone, with no tubing or inner production string used to bring formation fluids to the surface.

This type of completion has its best application in low-pressure, dry-gas reservoirs.

Tension tool

A retrievable or drillable packer in which sufficient pipe weight is not available to set the tool in compression.

Tank strapper

The person who measures a tank to determine the volume it holds at 1/4″ intervals of height.

Tubing slips

Slips designed specifically to be used with tubing.


The wellhead.


Running pipe or tubing and landing it on a downhole tool.

Top sub

A component of a packer to which the tubing is connected.