1. n. [Well Workover and Intervention]

A slickline tool generally used for the removal of sand or similar small particles around the fishing necks of downhole tools or equipment. The hydrostatic bailer incorporates a sealed atmospheric chamber and a shear pin, or similar activation mechanism, to allow communication with the wellbore. When the tool is activated, there is a fluid surge into the atmosphere as the pressure is equalized. A shroud arrangement at the base of the tool contains and directs the fluid surge to dislodge and capture any debris in the area.

Synonyms: sand bailer

See: fishing neck,  shear pin