SYSTEM FOR DRILLING A WELLBORE

摘要

A system is disclosed for drilling a wellbore (1) into an earth formation. The system comprises an expandable tubular element (4) extending into the wellbore, whereby a lower end portion (11) of the wall of the tubular element (8) extends radially outward and in axially reverse direction so as to define an expanded tubular section (10) extending around a remaining tubular section (4) of the tubular element. The expanded tubular section is extendable by downward movement of the remaining tubular section relative to the expanded tubular section whereby said lower end portion (14) of the wall bends radially outward and in axially reverse direction.