An apparatus and method of installing a casing string in a borehole, the apparatus comprising a propulsion system movable through the borehole; the propulsion system comprising an attachment member; and the attachment member being engagable with the casing string causing the casing string to move with...http://www.google.de/patents/US6868913?utm_source=gb-gplus-sharePatent US6868913 - Apparatus and methods for installing casing in a borehole
