Patent ID: 8479843

Claim:
A system for drilling a wellbore into an earth formation, comprising: an expandable tubular element extending into the wellbore, wherein a lower end portion of the wall of the tubular element extends radially outward and in an axially reverse direction so as to define an expanded tubular section extending around a remaining tubular section of the tubular element, the expanded tubular section being extendable by downward movement of the remaining tubular section relative to the expanded tubular section whereby the lower end portion of the wall bends radially outward and in an axially reverse direction; a drill string extending through the remaining tubular section into the wellbore, such that a space is formed between the drill string and the remaining tubular section, the space containing a body of fluid exerting an inner pressure to the remaining tubular section, the drill string comprising a first fluid conduit for drilling fluid from surface into a open-hole wellbore section and a second fluid conduit for discharging drilling fluid from the open-hole wellbore second such that a return fluid stream flows through the second fluid conduit and not through the space between the drill string and the remaining tubular section; and sealing means arranged to seal the space from the open-hole lower section of the wellbore.