Interlocking, Full-Circumference Packer Slip

Abstract

A packer assembly constructed of individual slip segments which interlock to permit radial expansion and restrict axial movement. The slip segments are moved outwardly to set the packer by an actuator. Individual slip segments are easily and inexpensively manufactured.

What is claimed is: 
     
         1 . A slip assembly for a packer, comprising:
 one or more slip segments arranged around a mandrel, the individual slip segments having a first end and a second end, the first end having an interlocking feature which permits the slip segments to expand radially outwardly from the mandrel when actuated and which restricts axial movement of the slip segments when actuated; and   an actuator configured to actuate the slip assembly by moving the slip segments radially outwardly.   
     
     
         2 . The slip assembly of  claim 1  wherein the interlocking feature comprises an H-shaped feature configured to restrict axial movement of the slip segment in two opposite axial directions. 
     
     
         3 . The slip assembly of  claim 1  wherein the slip segments are first slip segments, the slip assembly further comprising second slip segments, the second slip segments having a cooperating interlocking feature, wherein the second slip segments are inverted relative to the first slip segments, and wherein the interlocking features permit the slip segments to move radially relative to the mandrel and inhibit the first and second slip segments from moving relative to one another axially. 
     
     
         4 . The slip assembly of  claim 1  wherein the slip segments have a ramped portion facing inward toward the mandrel, and wherein the actuator comprises a corresponding ramp portion configured to move axially against the ramp portion of the slip segments to cause the slip segments to move radially outwardly. 
     
     
         5 . The slip assembly of  claim 1  wherein the interlocking feature permits the slip segments to move circumferentially away from one another when actuated. 
     
     
         6 . The slip assembly of  claim 1  wherein the slip segments have an outwardly-facing setting surface having a non-uniform circumferential profile. 
     
     
         7 . The slip assembly of  claim 6  wherein the non-uniform circumferential profile comprises a herringbone pattern. 
     
     
         8 . The slip assembly of  claim 6  wherein the non-uniform circumferential profile comprises parallel slots cut in two or more directions to produce teeth on the profile. 
     
     
         9 . The slip assembly of  claim 6  wherein the non-uniform circumferential profile comprises semi-circular indentations protruding from the outwardly-facing setting surface. 
     
     
         10 . The slip assembly of  claim 1  wherein the slip segments have two or more ramped portions facing inward toward the mandrel, and wherein the actuator has corresponding ramped portions engaging the ramped portions of the slip segments. 
     
     
         11 . The slip assembly of  claim 1 , further comprising garter springs encircling the slip segments. 
     
     
         12 . The slip assembly of  claim 1  wherein the interlocking feature comprises a shoulder, a neck extending from the shoulder, and a tab extending from the neck, wherein the neck is narrower than the shoulder, and wherein the tab is wider than the neck. 
     
     
         13 . The slip assembly of  claim 1 , further comprising a shear screw in the slip segments configured to hold the slips in place relative to the mandrel until actuated, at which point the shear screw will shear and permit the slip segments to move relative to the mandrel. 
     
     
         14 . The slip assembly of  claim 1  wherein the slip segments are cast. 
     
     
         15 . The slip assembly of  claim 1  wherein the slip segments are carburized. 
     
     
         16 . The slip assembly of  claim 1  wherein the slip segments are curved to generally match the mandrel, and wherein the sides of the slip segments face adjacent slip segments and are generally flat and parallel with a radius of the slip assembly. 
     
     
         17 . The slip assembly of  claim 1 , further comprising one or more keys interspersed around the circumference to limit circumferential movement of the slip segments. 
     
     
         18 . A packer, comprising:
 a mandrel;   an actuator coupled to the mandrel and configured to actuate in response to a predetermined condition to set the packer;   slip segments having an interlocking feature at a first end and a setting surface at a second end opposite the first end, wherein adjacent slip segments are inverted such that the interlocking feature of each slip segment engages the interlocking features of two adjacent, inverted slip segments, wherein the interlocking features restrict axial movement and permit radial movement, and wherein the actuator causes the slip segments to move radially relative to one another to set the packer.   
     
     
         19 . The packer of  claim 18  wherein the slip segments are not deformed by the actuator. 
     
     
         20 . A method of actuating a packer, comprising:
 running the packer to a desired location in a downhole well;   actuating a setting mechanism to expand a slip assembly, wherein the slip assembly comprises a plurality of slip segments configured to move radially outwardly to engage a surface of the well and to restrict axial movement of the slip segments.   
     
     
         21 . The method of  claim 20  wherein actuating the setting mechanism does not deform the individual slip segments. 
     
     
         22 . The method of  claim 20  wherein actuating the setting mechanism comprises sliding slip segments relative to one another.