Downhole tool with actuable barrier

摘要

A downhole tool for use in a cased or lined well bore ( 40 ), the tool including a barrier ( 36 ) arranged on an outer surface of the tool. The barrier may be of a resilient material so that it can be deformed on actuation to control the passage of fluid between the tool and the casing or liner. Fluid flow is thus selectively diverted through flow paths ( 22 ) in the tool. Embodiments are described for actuating the barrier by hydraulic means and for filtering the fluid within the flow paths.