Patent ID: 7793726
Filing Date: 2010-09-14
Classification: E21B

Abstract:
1. A marine riser system for transferring fluid between a subsea well penetrating a subsurface formation beneath the seafloor and a vessel floating on the surface of the sea, the riser system comprising: a) a disconnectable buoy capable of connecting to a floating vessel; b) a plurality of hybrid risers, each of the hybrid risers comprising a vertical riser, a riser buoy attached to an upper portion of the vertical riser and a flexible jumper interconnecting the riser buoy and the disconnectable buoy; and c) an anchor that secures each of the hybrid risers to the seafloor such that the vertical riser is substantially vertical; wherein the hybrid risers are positioned about the disconnectable buoy so that the disconnectable buoy is horizontally balanced between the riser buoys within a balancing plane defined by the height of the riser buoys while disconnected from the floating vessel.