Patent ID: 8622121
Filing Date: 2014-01-07
Classification: E21B

Abstract:
1. A wellhead apparatus, comprising: a wellhead member having a vertical bore for receiving an upper end of a string of conduit extending into a well; a sleeve carried within the bore of the wellhead member, wherein the sleeve isolates the bore of the wellhead member from a high pressure fluid injected into the sleeve; a flange formed on an upper end of the wellhead member, the flange having an upper surface and a lower surface, the flange having a passage extending therethrough from the upper to the lower surface for receiving a threaded bolt; an annular wedge ring located adjacent the lower surface of the flange and having a downward facing tapered shoulder formed on an outer diameter so that when a nut is tightened onto the bolt, a radial inward component of a tightening force on the bolt is applied through the tapered shoulder of the ring and to the flange, the radial component of the force countering tensile stress induced on the flange by the high pressure fluid injected into the sleeve; and a segmented washer installed between the nut on the bolt and the lower surface of the flange, wherein a gap is maintained between the washer and the lower surface of the flange when the flange is made up and the nut is tightened on the bolt, wherein the washer is comprised of two semi-circular halves that are fastened to each other by screws that correspond to passages formed at joining ends of the washer, and wherein the washer has a tapered shoulder formed on an interior diameter of the washer that is in contact with the correspondingly tapered shoulder formed on the outer diameter of the wedge ring so that the tightening force from the nut is transmitted from the washer, to the tapered shoulder of the washer, to the tapered shoulder of the wedge ring, such that a radial inward component of the tightening force is applied to the flange.