Patent ID: 9464481
Filing Date: 2016-10-11
CPC Classification: E21B

Claim Text:
1. A method for radially expanding a tubular element, the method comprising the steps of: bending the tubular element radially outward and in axially reverse direction so as to form an expanded tubular section extending around an unexpanded tubular section, wherein bending occurs in a bending zone; increasing the length of the expanded tubular section by pushing the unexpanded tubular section in axial direction relative to the expanded tubular section; operating a drill string, which extends through the unexpanded tubular section and is provided with a drill bit at a downhole end thereof, to drill a borehole; and operating directional drilling means, which are coupled to the drill string, to deviate the borehole and direct the borehole along a predetermined path, wherein the directional means include reference means for indicating a relative distance between the drill bit and the bending zone, wherein the reference means include: a positioning tool and a pressure release system, wherein the positioning tool includes at least one gripper for engaging the bending zone, and wherein the pressure release system includes at least one spring loaded valve, which is coupled to the at least one gripper, for opening or closing a corresponding opening in the drill string depending on the position of the at least one gripper relative to the bending zone.