US Patent 7819199 Method and a device for setting a casing

A method for setting a casing in a reduced diameter portion of a well bore whereby at least one annular packer may be positioned on an external surface of the casing and the packer may be conveyed into the reduced diameter portion of the well bore, thereby setting the casing. Cement can then be used to fill a region of an annulus formed between the external surface of the casing and the well bore above the packer. The packer may be preloaded, swellable, or expandable. The packer can be conveyed by applying a differential pressure to the packer, which longitudinally displaces the packer relative to the casing and forces the packer into the reduced diameter portion of the well bore.