Riser support system

Abstract

A riser system for offshore oil and gas production for communicating systems located on the seabed with floating facilities suitable for accommodating floating facility static and dynamic offsets and motions. The riser system comprises a riser extending from the seabed to a floating facility that is supported by a hybrid support system.

1 . A riser system suitable for offshore oil and gas production for communicating systems on the seabed with floating facilities comprising
 a riser extending from the seabed to a floating facility, said riser is supported by a hybrid support system wherein the hybrid supporting system comprises a mid depth tower and a mid depth buoyant support.   
     
     
         2 . A riser system of  claim 1  wherein the mid depth buoyant support structure of the hybrid supporting structure comprises buoyant enclosed structure tethered to the seabed arranged to raise and support at a point over a span of the riser for providing a sagging portion of the riser. 
     
     
         3 . A riser system of  claim 1  wherein the mid depth buoyant support of the hybrid support system includes an axial, horizontal and vertical restraint with suitable over curvature protection. 
     
     
         4 . A riser of  claim 1  wherein the mid depth tower of the hybrid support system comprises rigid steel like structure offering full translational and rotational restraint for the riser and the termination of which is placed in a vertical and horizontal position, with correctly selected lengths of riser so as to offer compliance for the riser section connected to it. 
     
     
         5 . A riser of  claim 1  wherein the mid depth tower having a termination end connectable to the riser comprises of a rigid steel pipeline connection of dynamic riser. 
     
     
         6 . A riser of  claim 1  wherein the mid depth tower termination end of the riser comprises a continuos dynamic section of riser, laterally constrained all the way to the seabed and then continuing along the seabed to connect to seabed infrastructure.