Patent ID: 7237617

Claim:
A downhole tool for location on a work string, the tool comprising: a substantially tubular body: a drive system; an assembly located upon the tubular body, the assembly operable from the work string by the drive system and disengagable from the work string at a selected location in the well bore; and retrieval means to pick up and engage the assembly on retrieval of the work string from the well bore; wherein the drive system comprises a plurality of longitudinally extending planar sections arranged around a circumference of a portion of an outer surface of the body and a plurality of longitudinally extending sections on a portion of an inner surface of the assembly, the sections of the assembly matching those of the body such that, when the portion of the outer surface of the body and the portion of the inner surface of the assembly are aligned and the work string rotated, the body is rotated by the work string and the assembly is rotated by the body; and wherein the retrieval means comprises a shoulder on the inner surface of the assembly and a ledge defined by the planar sections of the body which ledge engages the shoulder on the assembly when the tool is retrieved from the well bore.