Abstract: A system and a method are provided for managing the weight of an underwater riser assembly. The system includes a blocking mechanism for selectively blocking the bottom end of the riser assembly so that heavy drilling mud is retained within the riser assembly. Upper and lower flooding valves are located in the riser assembly above the blocking mechanism and are spaced apart. The valves can be opened so that an annulus in the riser assembly is in fluid communication with surrounding water. Drilling fluid can be introduced to or removed from the annulus during deployment or disconnect conditions using the upper and lower flooding valves. For the blocking mechanism, an elongated cylindrical tool can fill the annulus at the bottom end of the riser assembly to block fluid flow in the annulus.

Abstract: The present invention relates to an improved apparatus and method for minimizing vortex induced vibrations and hydrodynamic drag of a drilling riser. Vortex induced vibrations and hydrodynamic drag are minimized by installing on a drilling riser streamlined faring sections. The fairing sections are installed on and removed from a riser through the use of one or more door panels on a rounded front portion that have a latch mechanism which can be easily opened and closed. The fairing sections are configured so they can nest one inside the other for easy storage. A tapered back or tail section of each fairing section has an attachment receptacle for engagement by a handling mechanism with a telescoping arm for grasping the fairing section. The handling mechanism is designed to move the fairing sections between a rack, where they are stored, and a position adjacent to the riser.

Abstract: A mooring system for mooring a vessel off-shore, which comprises a block located in the water at a depth below expected wave action and at a distance from the vessel; a mooring line extending from line pulling equipment on the vessel, through the block and back, for releasable attachment to the vessel; mooring tackle attached to the block and extending away from the vessel to an anchor. The mooring line and mooring tackle form a catenary, between the vessel and the anchor, which has a curve adapted to maintain the anchor securely attached to the bottom and to maintain the block below the depth of expected wave action. Preferably, the mooring line passes from the pulling equipment through a fairlead located near the vessel's waterline, and then to the block.