Conventional steel risers are used to convey oil and gas between the production wells and the floating platforms in deep water exploitation. In this case, the water depth ranges from 1,000 to 1,500 m. The weight of such structures sometimes requires the use of costly alternative systems, like floaters, tendons and supports. When the water depth ranges from 1,500 to 4,000 m, i.e., ultra deep water fields, conventional steel risers may become prohibitive due to the high costs associated, as well as in terms of their feasibility, due to their weight.
These obstacles may be overcome by a new generation of advanced materials, which allow significant reduction of the structure weight reducing, thus, the stress on the platform connection. Among them, the ones with heterogeneous constitution are highlighted. These kind of materials gradually change their composition and structure gradually over volume (Functionally Graded Material – FGM), or exhibit abrupt changes in their properties, like the laminates, fiber reinforced composites etc. Such mixture aims at capturing benefits from each constitutive element, providing innovative engineering solutions which will allow oil exploitation at ultra deep waters. Given the innovative aspects of the proposal, we intend to perform a preliminary technical and economic feasibility study of the use of heterogeneous risers for ultra deep water oil exploitation.