Patent ID: 7632044
Filing Date: 2009-12-15
Classification: E21B

Abstract:
1. An offshore facility, having a floating platform, a riser having a lower end secured to subsea equipment and an upper portion extending through an opening in the platform, an improved riser tensioner, comprising: a frame stationarily mounted to the upper portion of the riser; a plurality of pistons and cylinders spaced circumferentially around the opening, each piston and cylinder being mounted between the frame and the floating platform, the cylinders being supplied with a pressurized fluid to apply tension to the riser; a tubular guide member mounted to the floating platform for movement in unison in response to waves and currents, the riser extending through the guide member; a guide roller support stationarily mounted to and extending downward from the frame around the guide member; and at least one set of guide rollers mounted to the guide roller support, spaced circumferentially around the guide member and in rolling engagement with the guide member as the guide member moves in unison with the platform.