Patent ID: 8960304
Filing Date: 2015-02-24
Classification: E21B

Abstract:
1. An underwater fluid transport installation for transporting vertically a fluid between a sea bed and a sea surface above the sea bed, the fluid transport installation comprising: a riser having a top retaining end, the riser configured to extend to the sea bed and connected to a flexible duct to extend toward the sea surface, a retaining float in a single piece installed around the riser, the retaining float secured at the top retaining end of the riser and configured to keep the riser stretched in suspension between the sea bed and a subsurface zone situated between the sea bed and the sea surface, while the flexible duct extends in a catenary between the riser and the sea surface; and an additional float installed between the top retaining end of the riser and the sea surface; wherein the riser is coupled to the additional float to increase the buoyancy of the riser, the retaining float and the additional float each have a diameter less than 5 meters and the floats have a combined volume of at least 800 m wherein the retaining float includes a bearing edge, and the top retaining end of the riser includes a collar forming a shoulder configured to rest on the bearing edge.