Patent ID: 9074427
Filing Date: 2015-07-07
Classification: E21B

Abstract:
1. A riser assembly for transporting fluids from a sub-sea location, comprising: a riser comprising at least one segment of flexible pipe; two or more buoyancy elements connected to the at least one segment of flexible pipe for providing a positive buoyancy to a portion of the riser and to form a steep or lazy wave configuration; and two or more tethering elements connected to at least one of the buoyancy elements for tethering the at least one of the buoyancy elements to a fixed structure, the tethering elements in constant tension to thereby provide axial and lateral support to the riser, and to resist the positive buoyancy of the buoyancy elements; wherein the buoyancy elements are sufficiently positively buoyant such that an upward force is created on the riser and such that, if the downward force or weight of the riser increases, there is sufficient upward force from the buoyancy elements to ensure the two or more tethering elements remain in constant tension, and wherein the two or more tethering elements are arranged to provide an opposite force to the upward force of the buoyancy elements.