cement is then allowed to set up after which the hole can be extended and the process repeated with another liner or the hole can be completed and put into production rotation of the tool t with the packer p set is enabled by bearings 121 123 131 and 132 which allow all the components not fixated by the sealing effect of the seal assembly 78 when set to relatively rotate while the cement is delivered rotary seals 133 and 134 beneath packer p allow for a pressure differential across packer p while relative rotation occurs between packer p and dual bore mandrel 15 fig6 9 is another embodiment that has some similarities to the embodiment described above but has some mandrel manipulation to assume the necessary positions for accomplishing top down cementing it will be described in a more abbreviated manner assuming the detailed discussion above of the first embodiment has provided a general background as to the tool configuration for top down cementing a mandrel 200 supports an outer housing 202 on opposed bearings 204 and 206 so that when a cementing packer 208 is set the mandrel 200 can rotate relatively to the outer housing 202 components held fixed by the set packer 208 inside the mandrel.