Patent ID: 6848506
Filing Date: 2005-02-01
Classification: E21B

Abstract:
1. A downhole retrieval tool for use in a drill string, wherein the drill string comprises a plurality of dual-member pipe sections, each dual-member pipe section comprising a hollow outer member and an inner member positioned longitudinally therein, wherein the outer member is connectable with the outer members of adjacent pipe sections and the inner member is connectable with the inner members of adjacent pipes sections, wherein the interconnected inner members are rotatable independently of the interconnected outer members, the downhole retrieval tool comprising: a housing connectable with the outer member of the dual-member drill string, wherein in response to movement of the outer member the housing may be moved to a particular position; a rotatable member supported by the housing and operable by rotation of the interconnected inner members of the drill string; and a gripping assembly operatively connected to the rotatable member for movement between a gripping position and a non-gripping position in response to rotation of the rotatable member.