Patent ID: 8657536
Filing Date: 2014-02-25
Classification: E21B

Abstract:
1. A riser tensioner system for tensioning a riser at an offshore vessel, comprising: a frame adapted to affix to the vessel and defining a riser receiving opening; and an elongate axial flange coupled to and projecting laterally outward from a tubular flow portion of the riser and extending axially along a length of the riser; and a plurality of ram pistons arranged about the riser receiving opening and coupled to the frame, the ram pistons adapted to couple to the riser and be pressurized to extend axially to support the riser in tension; and a plurality of centralizer arms coupled to the frame and extending into proximity to the flange of the riser when the riser is received through the riser receiving opening, the plurality of centralizer arms comprising a first centralizer arm adapted to bear on a first side of the axial flange and a second centralizer arm adapted to bear on a second, opposing side of the axial flange to maintain the riser in a specified position relative to the frame and counter rotation of the riser on its longitudinal axis.