Arrangement in a gripper mechanism for a free pipe/rodlike end portion of a downhole tool

Abstract

A gripper mechanism () suspended in a coiled tubing/wireline in a well serves to releasably hold a downhole tool or other piece of equipment positioned downstream, via a tubular connecting element (). The gripper mechanism () comprises axially, two relative to each other, movable coaxial parts (), a gripping part () designed to grip said connecting element () and an actuating part () designed to exert a radial clamping effect on the gripping portion () of the gripping part () when this is in engagement with said connecting element (). The clamping effect is due to complimentary conical face on opposite sides of the two parts () of the gripper mechanism () being forced against each other by the axial displacement of one part () relative to the other part () in one direction (the upstream/pull-up direction). In order to enable a small cone/coning angle to be used at these complimentary conical faces, while at the same time ensuring that the conical faces do not get wedged to each other across a longitudinal course in the axial direction, the conical faces of each part (and) have been divided, so that each conical face comprises annular conical part faces () and intermediate annular cylindrical part faces (). The conical part faces () have a mutually equal amount of taper and the same axial extent. The intermediate cylindrical part faces () have a mutually equal axial extent.