Patent ID: 9217517
Filing Date: 2015-12-22
Classification: E21B,F16L

Abstract:
1. A method for installing an underwater riser to transport hydrocarbons between a seabed and a sea surface, the method comprising: in the following order, providing a surface installation, providing a float suitable for floating on said sea surface; providing a tubular pipe that has two opposite ends; suspending said tubular pipe from said float by one of said two pipe ends, while said suspended tubular pipe extends toward said seabed; providing a flexible pipe at said surface installation; linking said float and said surface installation with said flexible pipe by connecting said flexible pipe to said one of said tubular pipe ends; simultaneously, driving the other of said two pipe ends toward said seabed and submerging said float from said sea surface to below said sea surface by selectively unwinding said flexible pipe from said surface installation to extend said flexible pipe in a catenary fashion between said float and said surface installation to weigh down said float with said unwound flexible pipe to cause said submerging of said float and to drive the other of said two pipe ends towards said seabed; and connecting the other of said two pipe ends to the bottom installation at said seabed.