SS: Fiber Moorings, Recent Experiences and Research: Moorings with Polyester Ropes in Petrobras: Experience and the Evolution of Life Cycle Management

Abstract

This paper describes the experience of Petrobras in the design, installation and operation of deepwater mooring systems incorporating high efficiency polyester fiber ropes. These ropes have been used now for more than 12 years in catenary and taut configurations to moor drilling and production units as well as storage and offloading facilities. The paper provides a history of the development of this technology, highlighting the key issues involved in introducing in mooring systems a component that has non-linear visco-elastic behavior. Differences to all steel systems in terms of: behavior, failure modes and design criteria and procedures are discussed. The paper presents the life cycle management strategy adopted by Petrobras in the early years of the use of this technology and its evolution that have guaranteed that the only failure mode observed over all these years was mechanical damage. It is expected that this paper shows that the use of polyester (polyethylene terephthalate) ropes in deepwater moorings is a mature technology.