Hybrid Composite Flexible Risers in Free Hanging Catenary Configuration and Flowlines for UDW Projects

Abstract

Large diameter UDW flexible pipes usually require lazy-wave configuration to withstand operational fatigue life. In a response to the current uncertain oil/gas price, the opportunity to design and deploy Free Hanging Catenary risers has been identified as the means to significantly lower CAPEX of flexible risers installed while securing the required life-cycle performance, including optimized offshore installation, 30-year fatigue duties. The most promising concepts to deliver free hanging configuration are based on composite flexible pipe designs, but these solutions rely on new technology (or at least new application of technology) and will need to undergo all new technology development phases including "Field Qualification" stage before they are ready to be considered as a base case for any UDW Project. Composite flexible pipe considers the adoption of new composite materials layers replacing one or multiple layers of a conventional flexible pipe for at least one pipe section. Several new hybrid pipe concepts can be developed considering this approach. Considering current Industry Standards and Brazil Regulations many challenges can be identified to deploy this type of new technology. These pipe concepts do not fit in the definition of existing Standards. In addition, the unknown behavior of these material and layers in a flexible pipe will increase the integrity assessment complexity. During the development phase the integrity assessment challenges and potential gaps in industry standards will have to be addressed as well to avoid misalignment or conflicts with regulatory requirements.