Dump Bailer

摘要

A dump bailer, comprising:
- a tool body (10) defining a chamber (12) for containing a material to be deposited;
- an outlet in the tool body through which the material can be deposited; and
- a piston assembly slideably mounted in the chamber and comprising a swabbing piston (20), a supply of pressurised fluid, and a valve (42) for releasing the pressurised fluid to act on the swabbing piston to drive it along the chamber to expel material contained therein through the outlet (16).