TD

Target depth. The depth the producing formation is expected to be encounter, or the depth to which a well is being drilled. Target depth is measured along the length of the well bore, and as such is not to be considered a true vertical or an independent measurement.

Telescopic Joint

Positioned at the top of the riser, the telescopic joint is comprised of an inner and outer barrel which can be stroked to compensable for rig heave or movement placed on the riser.

Tension Ring

Attached to the telescopic joint, it is used to pull tension on the riser string, to increase stability. The tension ring forms a termination point between the riser system and tensioning system on a floating rig.

Tie-In

The action of connecting one pipeline to equipment, or to another pipeline.

Tie-In System

Connection equipment, typically connecting flowlines, umbilicals and jumper spools. Tie-In systems are predominantly vertical or horizontal application methods.

TVD

True vertical depth. Measured vertically from a point in the surface to a certain point below. In comparison, TD is the length measured along the path of the well bore, which might not be vertical.