Drillable slip

A method of anchoring a downhole tool in a wellbore casing comprising:

• introducing said downhole tool into said casing wherein said downhole tool has a mandrel, a slip ring positioned on said mandrel and a slip wedge positioned on said mandrel, wherein said slip ring comprises:
• two or more slip segments integrally formed into said slip ring to produce a central aperture adapted to receive said mandrel, said slip segments having an outer surface and;
• two or more grooves are on the slip ring and one groove is longitudinally positioned between said slip segments, wherein a first portion of said grooves define fracture channels such that said slip segments are frangiblely connected together and said slip segments will separate along said first portion of said grooves upon application of a predetermined primary radial force;
• and
• a plurality of generally circumferentially extending wickers upon said outer surface wherein each wicker has a cutting edge;
• and wherein each slip segment has a longitudinally extending centerline;
• and wherein each slip segment and each wicker is configured such that, upon expansion of said slip ring in said casing, a contact point on said cutting edge and at or near said centerline will meet said casing before any portion of said cutting edge at or near said groove;
• positioning said downhole tool at a desired location;
• applying a setting force to said downhole tool such that said slip wedge engages said slip ring so as to provide a radial force at least equal to said predetermined primary radial force to said slip ring and thus causing said contact point to penetrate said casing;
• and
• increasing said radial force applied to said slip ring such that the majority of said cutting edge penetrates said casing.

A slip ring for anchoring a downhole tool in a wellbore casing having an inner wall, said slip ring comprising:

• four or more slip segments integrally formed into said slip ring, wherein each slip segment has an outer surface;
• two or more primary grooves are on the slip ring and one primary groove is longitudinally positioned between said slip segments wherein said primary grooves define fracture channels such that said slip segments are frangiblely connected and said slip segments will separate along said primary grooves into pairs upon application of a predetermined primary radial force;
• two or more secondary grooves are on the slip ring and one secondary groove is longitudinally positioned between said slip segments forming said pairs, wherein said secondary grooves define fracture channels such that said pairs of slip segments are frangiblely connected and will separate upon application of a predetermined secondary radial force and wherein said predetermined secondary radial force is greater than said predetermined primary radial force;
• and
• a plurality anchors upon said outer surface;
• and wherein each slip segment has a longitudinally extending centerline;
• wherein each slip segment and each anchor is configured such that, upon expansion of said slip ring by said predetermined primary radial force in said casing, said anchors at or near the centerline will meet said inner wall of said casing;
• and wherein said slip segments are configured such that a portion of said anchors along said longitudinal extending centerline will meet said inner wall of said casing prior to any other portion of said anchors.

A method of anchoring a downhole tool in a wellbore casing comprising:

• introducing said downhole tool into said casing wherein said downhole tool has a mandrel, a slip ring positioned on said mandrel and a slip wedge positioned on said mandrel, wherein said slip ring comprises:
• four or more slip segments integrally formed into said slip ring, wherein each slip segment has an outer surface;
• two or more primary grooves are on the slip ring and one primary groove is longitudinally positioned between said slip segments wherein said primary grooves define fracture channels such that said slip segments are frangiblely connected and said slip segments will separate along said primary grooves into pairs upon application of a predetermined primary radial force;
• two or more secondary grooves are on the slip ring and one secondary groove is longitudinally positioned between said slip segments forming said pairs wherein said secondary grooves define fracture channels such that said pairs of slip segments are frangiblely connected and will separate upon application of a predetermined secondary radial force wherein said predetermined secondary radial force is greater than said predetermined primary radial force;
• and
• a plurality anchors upon said outer surface;
• and wherein each slip segment has a longitudinally extending centerline;
• and wherein each slip segment and each anchor is configured such that, upon expansion of said slip ring by said predetermined primary radial force in said casing, said anchors at or near the centerline will meet said inner wall of said casing;
• and wherein said anchors are generally circumferentially extending wickers and each wicker has a cutting edge and wherein each slip segment and each wicker is configured such that, upon expansion of said slip ring in said casing, a contact point on said cutting edge and at or near said centerline will meet said casing before any portion of said cutting edge at or near said groove;
• positioning said downhole tool at a desired location;
• and
• applying a first setting force to said downhole tool such that said slip wedge engages said slip ring so as to provide a radial force at least equal to said predetermined primary radial force to said slip ring and thus causing said anchors to penetrate said casing.