Internal bore impression tool

Abstract

A tool (10) for taking an impression of an area of the internal bore of a tubular member (16) or a joint between two such members comprising means for directing a casting compound between two flexible membranes (20, 22) which are then forced outwardly so that the outer membrane (22) engages the area to be inspected within a bore where the compound forms a resilient mold (cast). When the force against the membranes and mold is removed, the membranes and mold collapse allowing the mold and tool (10) to be retrieved out the bore. The tool (10) carries casting compound in two parts unmixed to the area to be inspected where a selected amount of working fluid (60) under preselected pressure from a fluid source (18) of a selected volume will open a valve (42) then force the two parts to be mixed and directed between two flexible membranes (20, 22). The remainder of the working fluid (60) under pressure from the fluid source will then be directed via another valve (54) behind the membranes to inflate (expand) the two membranes (20, 22), with the compound therebetween, against the area to be inspected. This also distributes the compound uniformly within the membranes. After the compound has cured, the working fluid (60) under pressure holding the membranes expanded will be directed out by another valve (54) from behind the membranes, allowing the membranes and mold to collapse. The fluid in the fluid source is pressurized by a pressure source outside the tool, such as fluid (18) in a drill string. The invention also disclosed is a method of taking an impression of an area to be inspected.

Dependencies are inferred from the claim text.