1. n. [Well Completions, Well Workover and Intervention]

Similar to a fracturing mandrel, a fracturing sleeve is temporarily inserted into a wellhead before the fracturing process begins to isolate low-pressure connections from the higher fracturing pressures. Fracturing sleeves differ from fracturing mandrels in that the fracturing sleeve is fully contained within the wellhead, and the frac tree is installed on the wellhead, not the sleeve.

See: mandrel