Slip Assembly for Anchoring Downhole Plugs and Retainers

Abstract

A downhole plug assembly can be installed at a desired location within a subterranean wellbore that is capable of isolating one portion of the wellbore from another, while sealing fluid pressure within the wellbore from at least one direction. The plug assembly can include certain components constructed of non-metallic material that can be drilled, milled or mechanically broken up more quickly and efficiently than conventional wellbore plugs, thereby facilitating removal of said plug assembly when desired.

What is claimed: 
     
         1 . A slip assembly for gripping an internal surface of a wellbore comprising:
 a) a cone member having a plurality of recessed slots disposed in spaced relationship around the outer circumference of said cone member, wherein said recessed slots define inclined surfaces;   b) a plurality of slip members, each having a leading end and a trailing end, wherein at least one slip member is slidably disposed within each of said recessed slots; and   c) a push ring operationally linked to said slip members, wherein axial movement of said push ring toward said cone member causes said slip members to interact with said inclined surfaces and extend radially outward.   
     
     
         2 . The slip assembly of  claim 1 , wherein each of said slip members are wedge-shaped. 
     
     
         3 . The slip assembly of  claim 2 , wherein each wedge-shaped slip member is slidably disposed on an inclined surface of a recessed slot of said cone member, 
     
     
         4 . The slip assembly of  claim 1 , wherein each of said slip members further comprises at least one dovetail projection extending laterally from said slip member at said trailing end. 
     
     
         5 . The slip assembly of  claim 4 , wherein each of said dovetail projections is slidably disposed within an aligned recess in said push ring. 
     
     
         6 . The slip assembly of  claim 5 , wherein each dovetail projection travels within said aligned recess in a direction that is substantially normal to said push ring. 
     
     
         7 . The slip assembly of  claim 1 , wherein each of said slip members further comprises at least one lateral ledge member slidably disposed within an elongate track in said cone member. 
     
     
         8 . The slip assembly of  claim 7 , wherein each of said elongate tracks is oriented substantially parallel to an inclined surface of a recessed slot. 
     
     
         9 . The slip assembly of  claim 1 , further comprising at least one wicker or button disposed on an outer surface of at least one slip member. 
     
     
         10 . The slip assembly of  claim 9 , wherein said at least one wicker or button comprises powdered metal and composite matrix material. 
     
     
         11 . A slip assembly for gripping an internal surface of a wellbore comprising:
 a) an elongate central mandrel;   b) a cone member disposed on said mandrel and having a plurality of recessed slots disposed in spaced relationship around the outer circumference of said cone member, wherein each of said recessed slots is oriented substantially parallel to the longitudinal axis of said central mandrel and defines an inclined surface;   c) a push ring releasably attached to said central mandrel; and   d) a plurality of wedge-shaped slip members slidably disposed within said recessed slots, wherein each slip member has a leading end, a trailing end, an outer surface, an inclined inner surface, and at least one dovetail projection extending laterally from said trailing end and moveably disposed within an aligned recess in said push ring oriented substantially normal to the longitudinal axis of said central mandrel.   
     
     
         12 . The slip assembly of  claim 11 , wherein axial movement of said push ring toward said cone member causes said inclined inner surfaces of said slip members to interact with said inclined surfaces of said recessed slots and extend radially outward toward said wellbore internal surface. 
     
     
         13 . The slip assembly of  claim 11 , wherein each of said slip members further comprises at least one lateral ledge member slidably disposed within an elongate track in said cone member. 
     
     
         14 . The slip assembly of  claim 13 , wherein each of said elongate tracks is oriented substantially parallel to an inclined surface of a recessed slot. 
     
     
         15 . The slip assembly of  claim 11 , further comprising at least one wicker or button disposed on an outer surface of at least one slip member. 
     
     
         16 . The slip assembly of  claim 15 , wherein said at least one wicker or button comprises powdered metal and composite matrix material. 
     
     
         17 . A slip assembly for gripping an internal surface of a wellbore comprising:
 a) an elongate central mandrel;   b) a cone member disposed on said mandrel and having a plurality of recessed slots disposed in spaced relationship around the outer circumference of said cone member, wherein each of said recessed slots is oriented substantially parallel to the longitudinal axis of said central mandrel and defines an inclined surface;   c) a push ring releasably attached to said central mandrel; and   d) a plurality of wedge-shaped slip members, slidably disposed within said recessed slots, wherein each slip member has a tapered leading end, a trailing end, an outer surface, an inclined inner surface, at least one lateral ledge member slidably disposed within an elongate track in said cone member oriented parallel to an inclined surface of a recessed slot, and at least one dovetail projection extending laterally from said trailing end and moveably disposed within an aligned recess in said push ring oriented substantially normal to the longitudinal axis of said central mandrel.   
     
     
         18 . The slip assembly of  claim 17 , wherein axial movement of said push ring toward said cone member causes said inclined inner surfaces of said slip members to interact with said inclined surfaces of said recessed slots and extend radially outward toward said wellbore internal surface. 
     
     
         19 . The slip assembly of  claim 17 , further comprising at least one wicker or button disposed on an outer surface of at least one slip member. 
     
     
         20 . The slip assembly of  claim 19 , wherein said at least one wicker or button comprises powdered metal and composite matrix material.