Verktøy med segmentert flerstørrelses-sete

A tool for use in subterranean hydrocarbon production comprising a housing defining an axial flowbore and having an outer lateral fluid port 40 formed therein; a piston sleeve 44 axially moveably disposed within the flowbore and having an inner lateral fluid port 50, the piston sleeve 44 being moveable between a first position corresponding to a first operating position for the tool, and a second position corresponding to a second operating position for the tool; an actuation mechanism for moving the tool between the first and second operating positions, the actuation mechanism comprising a seat 52 associated with the piston sleeve 44 to catch and release a plug, the seat 52 being retained within an expansion chamber 32 and formed of a plurality of separate arcuate segments which define an annular seat having a central opening; wherein the seat further comprises an annular base ring 92 and a plurality of collets 94 that extend axially from the annular base ring 92 to interconnect each arcuate segment 96 with the base ring 92; wherein a) the actuation mechanism moves the tool from the first operating position to the second operating position by landing a first actuation plug onto the seat and thereafter varying fluid pressure within the flowbore of the housing; and b) the actuation mechanism moves the tool from the second operating position to the first operating position by landing a second actuation plug that is of a different size than the first actuation plug onto the seat and thereafter varying fluid pressure within the flowbore of the housing; a first actuation plug; and a second actuation plug which is of a different size than the first actuation plug.