UNDER-REAMING AND STABILIZING TOOL FOR USE IN A BOREHOLE AND METHOD FOR USING SAME

摘要

The invention concerns an under-reaming and stabilizing tool comprising a tubular body (1) having an axial cavity (2) open outwards by at least one radial guide channel (3), a blade element (5, 6) arranged radially mobile in each radial guide channel, and wedge means (17, 18) which through an axial displacement inside the tubular body, induce a radial movement of each blade element (5, 6) as well as a drive tube (11) which is mounted inside said axial cavity so as to produce therein axial movements, the wedge means being supported at the periphery of the drive tube so as to perform between them a relative sliding movement, stop means being capable of releasably locking the wedge element on the drive tube in a locking position wherein the drive tube can produce its axial movements driving with it the wedge element.