Wellbore apparatus for setting a downhole tool

A first aspect relates to a method of separating a downhole tubular comprising running a tool (100, Fig 1) into a wellbore to a predetermined location on a work string. Flow actuated slips 220 are actuated and the slips are maintained in the set position by providing a first upward force on the work string. The work string is rotated to operate a cutter assembly disposed on the work string below the slips. This separates an upper portion of the tubular from a lower portion. The upper portion of tubing and the tool are pulled from the wellbore. A second aspect relates to a method of separating a downhole tubular that incorporates the features of the first aspect, in addition to applying a second higher upward force on the work string to unlock and set a packer 300; flowing fluid through the work string and into an annular area between tubular and a borehole; and reducing the second upward force on the work string to unset and re-lock the packer. The annular area is accessible through a cut formed between the upper and lower portions by the cutter assembly.