Coiled Tubing Glossary...

Ultrasonic Inspection: Testing through the use of ultrasonic waves to detect discontinuities or corrosion in metal structures.

Underbalance: Relating to a condition in which the pressure in the wellbore is less than the pressure in the formation.

Underreamer: A device used to underream. Usually to enlarge the wellbore below the casing.

Unit of Consistency: a standard value of measurement relating torque equivalent to degree of firmness of a cement slurry; replaced by the Bearden unit of consistency.

Unit: A piece or several pieces of equipment performing a complete function.

Unstable Spiral: Describes the section of CT, which is beyond the Neutral Point and is therefore in the Unstable region. By definition the CT has formed a helical spiral. However, sections of the CT are not in contact with the completion tubulars, e.g., due to a diameter change or a nipple. This will be the most likely place for a failure to occur.

Upset: To forge the ends of tubular products so that the pipe wall acquires extra thickness near the end. Usually upsetting is performed to provide the thickness needed to form threads so that the tubular goods can be connected, and still maintain the integrity of the pipe.

Useable Hydraulic Pressure: The hydraulic fluid volume recoverable from the accumulator system between the maximum designed accumulator operating pressure and the minimum operating pressure.

U-Tubing: The actions of fluid flowing in a U-tube (as heavy fluid forcing lighter fluid down the tubing and up the annulus).

Please inform ICoTA to add a glossary term.