in their expanded configurations due to any pressure differential acting in the annulus across either set of packing elements upward movement of mandrel 4 will equalize the pressure across upper packing elements 40 by establishing communication between the annulus above the injection tool through longitudinal bypass section 36 and through the injection port 50 to the annulus below packing elements 40 movement of the unloader seal 14 out of engagement with seal compressor 16 serves to establish such pressure equalization and pressure communication after pressure is equalized across upper packing elements 40 as a result of movement of unloader seal 14 away from seal compressor 16 any pressure differential existing across packing element 60 can be relieved as the lower unloader seal 54 moves from within the restriction in lower bypass section 66 to the larger diameter portion proximate to outer injection port 50 a pressure equalization path is then established from the annulus below the packing element 60 through port 68 through the lower longitudinal bypass portion 66 through the injection port 50 to the annulus above lower packing element 60 this tool therefore provides an easily repeatable releasing procedure in which the mandrel 4 is merely manipulated in a longitudinal fashion to both release the packing elements 40 and 60 and the slips 74 and to equalize pressure across both sets of packing.