METHOD OF CREATING A BOREHOLE IN AN EARTH FORMATION

摘要

A method of creating a borehole in an earth formation is provided. The metho d comprises the steps of drilling a section of the borehole and lowering an expandable tubular element into the borehole whereby a lower portion of the tubular element extends into the drilled borehole section, radially expandin g said lower portion of the tubular element so as to form a casing in the drilled borehole section, and separating an upper portion of the tubular element from said lower portion so as to allow the separated upper portion t o be moved relative to said lower portion.