Release/anti-preset mechanism for down-hole tools

摘要

This invention relates to a release/anti-preset mechanism for retrieving a down-hole tool and for preventing premature actuation of the tool during insertion thereof into a subterranean well-bore. Release mechanisms for retrieving down-hole tools are known and can be divided into three main types: shear release systems, conventional wireline/coil tubing/drill pipe (WL, CT, DP) actuated systems and hydraulically activated systems. Known mechanisms suffer from a number of problems. Accordingly the present invention provides a retrievable down-hole tool (5) having a release/anti-preset mechanism comprising first and second members (10, 15) radially releasably engagable by a third member (20) which controls radial deflection of one of the first or second members (10, 15).