Abstract: A piston assembly (10) comprises a fluid actuated piston (14) mounted within a cylinder (12), and a fluid actuated locking mechanism (16) mounted within the cylinder (12) for selectively locking the piston (14) relative to the cylinder (12). In one arrangement, the piston (14) and locking mechanism (16) are actuated by fluid supplied via a common fluid port (48).

Abstract: A tool storage assembly (12) comprises a housing (28) defining a chamber adapted to be in fluid communication with a wellbore through a tool passage (30) formed in the housing (28). A tool storage member (32) is mounted within the chamber of the housing (28) and defines a tool compartment (34) adapted to releasably secure a downhole tool (22) therein. The tool storage member (32) is moveable between a storage position and a deployment position, wherein the tool (22) may be deployed into the wellbore when the tool storage member (32) is in the deployment position.