Patent ID: 9010436
Filing Date: 2015-04-21
Classification: E21B

Abstract:
1. An apparatus for providing tension to a riser, the apparatus comprising: a platform having a bore therethrough; a tubular member extending through the bore; an annular upper latch member connected to an outer diameter of the tubular member, the upper latch member having a downward facing latch recess on a bottom surface; and a retractable lower latch ring connected to the platform, the lower latch ring being movable in a plane generally perpendicular to an axis of the bore from an open position to a latch position, the open position allowing the upper latch member to pass through the lower latch ring and the latch position stopping downward axial movement of the upper latch member relative to the lower latch ring, the lower latch ring having a cylindrical guide extending upward in an axial direction and having an outer diameter that is less than an inner diameter of the latch recess when the lower latch ring is in the latch position so that the cylindrical guide can fit inside the latch recess.