Quarter Turn Tension Torque Anchor

Abstract

A torque anchor for anchoring well equipment in a well conduit to arrest movement in both longitudinal directions and rotation in a first direction, but not rotation in an opposed second direction. A mandrel connected to the equipment has L-shaped grooves for slideably receiving respective pins from a drag body on the mandrel. A slip retainer on the mandrel houses slips for selectively engaging and disengaging the conduit. An initial pull of the mandrel causes the pins to move the drag body toward the slip retainer driving the slips outward to grip the conduit, and rotation of the mandrel in the first direction sets the anchor to arrest movement. Further pulling maintains the set position. The anchor is unset by releasing pull, rotating the mandrel in the second direction, and pushing the mandrel to disengage the slips. Alternate unsetting requires increased pull beyond the shear resistance of the slip retainer.

We claim: 
     
         1 . A torque anchor for anchoring well equipment in a well conduit to arrest movement in both longitudinal directions and rotation in a first direction comprising:
 a mandrel connected to said well equipment;   a cone element mounted to said mandrel and having a first conical surface;   a drag body mounted on said mandrel, housing a drag means for contacting said well conduit, and having a second conical surface;   a slip retainer mounted on said mandrel housing a plurality of slips, each of said slips having an inner surface, and an opposed outer surface for gripping said well conduit, and biasing means for urging said slip inwardly toward said mandrel and away from said well conduit;   at least one pin connected to said drag body and a portion of said pin protruding toward said mandrel; and,   said mandrel having at least one L-shaped groove for slideably receiving said protruding portion of said pin;   wherein an initial pulling of said mandrel causes said pin, and in turn said drag body, to move toward said cone element so that said second conical surface of said drag body contacts said inner surface of said slips and urges said inner surface to contact said first conical surface of said cone element to drive said slips outward so that said outer surfaces of said slips grip said well conduit, and a further rotation of said mandrel in said first direction sets said torque anchor.   
     
     
         2 . The torque anchor of  claim 1  wherein said L-shaped groove comprises:
 a first arm extending longitudinally on said mandrel having a shoulder at one end forming a first stop and an elbow at an opposed end; and, 
 a second arm having one end extending circumferentially from said elbow and an opposed end forming a second stop; 
 wherein said pin travels to said second stop when setting said torque anchor and travels to said first stop when unsetting said torque anchor. 
 
     
     
         3 . The torque anchor of  claim 2  further comprising an indent at said second stop of said second arm wherein a further pulling of said mandrel engages said pin with said indent to help maintain said torque anchor in a set position. 
     
     
         4 . The torque anchor of  claim 2  wherein said first arm is located generally perpendicularly to said second arm. 
     
     
         5 . The torque anchor of  claim 2  wherein said second arm is configured so that about one quarter turn of said mandrel is sufficient to bring said pin from said elbow to said second stop. 
     
     
         6 . The torque anchor of  claim 2  wherein said first arm provides about 2.5 mm of travel therein for said pin. 
     
     
         7 . The torque anchor of  claim 1  wherein a plurality of fasteners fixing said cone element to said mandrel are adapted to shear off to provide a secondary release means when said mandrel is pulled in tension in excess of the failure shear resistance of said fasteners. 
     
     
         8 . The torque anchor of  claim 1  wherein said inner surface of said of each slip forms opposed inclined edges for contacting said first and second conical surfaces to form a wedging action for urging said slip away from said mandrel. 
     
     
         9 . The torque anchor of  claim 1  wherein said slips are generally equidistantly spaced about said slip retainer to centre the torque anchor within the well conduit, and said slips radially protrude from said slip retainer to create large by-pass spaces therebetween for well fluids and equipment. 
     
     
         10 . A method of anchoring well equipment in a well conduit to arrest movement in both longitudinal directions and rotation in a first direction, and to allow rotation in an opposite second direction, using a torque anchor having:
 a mandrel connected to said well equipment;   a cone element mounted to said mandrel with fasteners;   a drag body mounted on said mandrel, housing a drag means for contacting said well conduit;   a slip retainer mounted on said mandrel housing a plurality of slips for moving into and out of gripping engagement with said well conduit;   at least one pin operatively engaging said drag body to said mandrel; and,   said mandrel having at least one groove with a first longitudinal arm and a second circumferential arm, for slideably receiving said pin;   
       wherein said method comprises:
 exerting an initial pull on said mandrel to move said pin along said first leg of said groove to extend said slips to grip said well conduit; and, 
 then rotating said mandrel in said first direction to move said pin along said second leg of said groove to set said torque anchor. 
 
     
     
         11 . The method of  claim 10  comprising exerting a further pull on said mandrel, after said rotation, to maintain said torque anchor in said set position. 
     
     
         12 . The method of  claim 11  wherein unsetting of said torque anchor comprises:
 releasing said pull on said mandrel; 
 rotating said mandrel in said second direction to move said pin along said second leg to said first leg; and, 
 moving the mandrel so that said pin travels along said first leg, thereby releasing said slips from said well conduit to allow said torque anchor to slide along said well conduit. 
 
     
     
         13 . The method of  claim 11  wherein a secondary unsetting of said torque anchor comprises increasing said further pull on said mandrel until the failure shear resistance of said fasteners is exceeded.