Patent ID: 9181761
Filing Date: 2015-11-10
Classification: B63B,E21B

Abstract:
1. A riser tensioning system for tensioning a riser extending from a subsea wellhead to a floating platform, the riser tensioning system comprising: a tensioning ring for secured engagement with the riser: a plurality of hydraulic cylinders each extending between the tensioning ring and the floating platform; a gimbal mechanism below the tensioning ring and acting between the platform and the riser and allowing the riser axis to tilt relative to the floating platform, wherein the gimbal mechanism comprises an inner ring having a first axis and an outer ring having a second axis, wherein the first axis is perpendicular to the second axis, wherein the gimbal mechanism accommodates tilting of the riser in any direction; and one or more elongate torque transfer members extending between the tensioning ring and gimbal mechanism, the one or more torque transfer members transferring riser torque from the tensioning ring through the gimbal mechanism and to the floating platform while allowing axial movement of the tensioning ring and the riser with respect to the floating platform.