Downhole tool and method of use

1. A downhole tool useable for isolating sections of a wellbore, the downhole tool comprising:

a mandrel made of composite material, the mandrel further comprising: a proximate end having a first outer diameter; a distal end having a second outer diameter; an external side having an angled linear transition surface; and a flowbore extending from the proximate end to the distal end;

a metal slip disposed about the composite mandrel, the metal slip comprising: a circular metal slip body; an outer surface comprising columns of serrated teeth; and an inner surface configured for receiving the mandrel,

a seal element;

a composite slip disposed about the mandrel, the composite slip further comprising a circular composite slip body having one-piece configuration with at least partial connectivity around the entire circular composite slip body, and an at least two slip grooves disposed therein, wherein the composite slip body further comprises a composite slip outer surface and a composite slip inner surface, wherein at least one of the at least two slip grooves forms a lateral opening in the composite slip body that is defined by a first portion of slip material at a first slip end, a second portion of slip material at a second slip end, and a depth that extends from the composite slip outer surface to the composite slip inner surface;

a first cone disposed around the mandrel, and proximately between an underside of the composite slip and an end of the seal element; and a lower sleeve disposed around the mandrel and proximate an end of the metal slip.

2. The downhole tool of claim 1 , wherein the metal slip is made from cast iron, wherein the metal slip is heat treated, and wherein the circular metal slip body comprises a plurality of longitudinal holes.

3. The downhole tool of claim 2 , wherein the outer surface has a Rockwell hardness in the range of about 40 to about 60, wherein the inner surface has a Rockwell hardness in the range of about 10 to about 25, and wherein the inner surface comprises a plurality of grooves.

4. The downhole tool of claim 1 , wherein the outer surface has a Rockwell hardness in the range of about 40 to about 60, wherein the inner surface has a Rockwell hardness in the range of about 10 to about 25, wherein the mandrel is made from filament wound material.

5. The downhole tool of claim 1 , wherein the metal slip is formed of hardened cast iron, and wherein the metal slip is configured with a low-density material disposed therein.

6. The downhole tool of claim 1 , wherein the composite slip comprises a circular composite slip inner surface, wherein the mandrel comprises a cylindrical outer surface proximately adjacent to where the composite slip is disposed therearound.

7. A downhole tool useable for isolating sections of a wellbore, the downhole tool comprising:

a mandrel made of composite material, the mandrel further comprising:

a distal end; a proximate end; and an outer surface, wherein the outer surface comprises a first outer diameter at the distal end, a second outer diameter at the proximate end, and an angled linear transition surface therebetween;

a bearing plate disposed around the mandrel, the bearing plate comprising an angled inner plate surface configured for engagement with the angled linear transition surface;

a metal slip disposed about the mandrel, the metal slip comprising an outer metal slip surface further comprising columns of gripping elements;

a sealing element disposed around the mandrel;

a composite one-piece slip disposed about the mandrel, the composite slip further comprising a circular composite slip body having one-piece configuration with at least partial connectivity around the entire circular composite slip body, and an at least two slip grooves disposed therein;

a first cone disposed around the mandrel, and proximately between an underside of the composite slip and an end of the seal element, the first cone having a completely smooth circumferential conical surface engaged with the underside of the composite slip; and

a lower sleeve engaged with the mandrel,

wherein the composite slip body further comprises a composite slip outer surface and a composite slip inner surface, wherein at least one of the at least two slip grooves forms a lateral opening in the composite slip body that is defined by a first portion of slip material at a first slip end, a second portion of slip material at a second slip end, and a depth that extends from the composite slip outer surface to the composite slip inner surface.

8. The downhole tool of claim 7 , wherein at least a portion of the outer metal slip surface is heat treated, and wherein the gripping elements comprise serrated teeth.

9. The downhole tool of claim 8 , wherein the metal slip is surface hardened, wherein the metal slip has a hardness profile defined by the outer metal slip surface having a Rockwell hardness in the range of about 40 to about 60, and the inner surface having a Rockwell hardness in the range of about 10 to about 25, and wherein the metal slip is made from cast iron.

10. The downhole tool of claim 9 , wherein the inner surface is configured with a plurality of substantially symmetrically arranged grooves disposed therein, wherein the metal slip is made from cast iron, and wherein the metal slip comprises a one-piece configuration.

11. The downhole tool of claim 10 , the downhole tool further comprising a composite member disposed around the mandrel and proximate to the sealing element, the composite member having a deformable portion with one or more member grooves disposed therein.

12. The downhole tool of claim 10 , wherein the second outer diameter is greater than the first outer diameter.

13. The downhole tool of claim 7 , wherein the composite slip comprises a circular composite slip inner surface and a composite slip outer surface, wherein the mandrel comprises a cylindrical outer surface proximately adjacent to the circular composite slip inner surface where the composite slip is disposed therearound.

14. A downhole tool for use in a wellbore, the downhole tool comprising:

a mandrel made of a composite material, the mandrel further comprising:

a distal end having a first outer diameter;

a proximate end having a second outer diameter;

an outer surface; a flowbore extending from the proximate end to the distal end; and

an angled linear transition surface on the outer surface between the distal and the proximate end,

wherein the second outer diameter is larger than the first outer diameter; a bearing plate disposed around the mandrel, the bearing plate comprising an angled inner plate surface configured for engagement with the angled linear transition surface; a metal slip disposed around the mandrel proximate to the distal end, the metal slip further comprising:

an outer metal slip surface configured with columns of gripping elements; and a one-piece metal slip body comprising a plurality of longitudinal holes disposed therein;

a seal element;

a composite one-piece slip disposed about the mandrel, the composite slip further comprising a composite slip body having one-piece configuration with at least partial connectivity around the entire composite slip body, and an at least two slip grooves disposed therein, wherein the composite slip body further comprises a composite slip outer surface and a composite slip inner surface, wherein at least one of the at least two slip grooves forms a lateral opening in the composite slip body that is defined by a first portion of slip material at a first slip end, a second portion of slip material at a second slip end, and a depth that extends from the composite slip outer surface to the composite slip inner surface;

a first cone disposed around the mandrel, and proximately between an underside of the composite slip and an end of the seal element; and

a lower sleeve coupled to the mandrel, and proximate to the metal slip.

15. The downhole tool of claim 14 , wherein the metal slip is surface hardened, wherein the outer metal slip surface has a Rockwell hardness in the range of about 40 to about 60, and wherein the metal slip is made from cast iron.

16. The downhole tool of claim 15 , wherein the metal slip comprises an inner surface configured with a plurality of grooves disposed therein, and wherein the inner surface has a Rockwell hardness in the range of about 10 to about 25.