Patent ID: 6223839
Filing Date: 2001-05-01
Classification: E21B

Abstract:
A packer section for use in a hydraulic underreamer comprising:a tubular drive bushing having an upper end and a lower end:a tubular packer mandrel having an upper end and a lower end, the packer mandrel lower end being mounted on the drive bushing with the packer mandrel lower end being closely adjacent to but not connected to the drive bushing upper end so that the drive bushing may rotate while the packer mandrel remains stationary;at least one tubular sealing element received on and around the packer mandrel;a tubular drive mandrel defining a packer section central bore therethrough and substantially coaxially extending through the drive bushing and packer mandrel so as to define a packer section annulus, the tubular drive mandrel being fixedly connected to the drive bushing so that rotation of the drive mandrel rotates the drive bushing.