1. n. []

The apparent increase in thickness of a casing or tubing string compared to the assumed value. Metal gain is determined by electromagnetic thickness, acoustic resonance, or mechanical methods. The apparent increase is usually due a change of hardware, such as a casing coupling, a heavier joint, a pup joint, a mandrel, or a valve. The term is used in contrast to metal loss caused by corrosion.

Antonyms: metal loss,  wall loss

See related terms: casing-inspection log,  electromagnetic thickness,  multifinger caliper,  ultrasonic caliper