(n.) Well Workover and Intervention. Another term for sand cleanout, the process of removing sand or similar fill from a wellbore. Many wells produce sand that may accumulate and restrict production if not removed from the wellbore by the production fluid. Coiled tubing and snubbingunits are routinely used for sand-cleanout operations, enabling the well condition to be treated without removing thecompletion equipment or even killing the well. Syn: sand cleanout