The scope of the paper is to further present and discuss, in continuation of OTC-28839-MS paper, the results of our technology development program regarding very long oil tiebacks architectures (50-100km) and enabling technologies. It is arrived the time when long tieback solutions are considered for real development projects. The paper will describe how those technological solutions compare with more conventional development schemes in concept selection phases and how our Operating Company is getting prepared for potential implementation. The paper will review key enabling technologies, together with their readiness level and discuss drivers for integration and operation. Sizing references will be presented as a result of Front End Engineering and Design activities developed for real project development opportunities. Technical performances will be discussed and technical-economic indicators will be provided. Risks during development and production will be analyzed and mitigation will be evaluated. A combination of heated high thermal performance flowlines, subsea multiphase boosting, subsea power management, innovative preservation procedures, newest subsea production components together with a reliable integrated control system and digital technologies are the key enablers of a very long tieback solution that may work as kind of highways to bring back production of a whole area to a production hub. Technically the way to go and the gap to cross appear manageable in mid to short terms opening new opportunities for deepwater asset development. It appears now possible to reduce deepwater development costs by increasing the distance between new assets and existing production hubs, shallow water areas or even connecting those assets to shore.

The scope of the paper is to present and discuss results of an extended technology development program regarding very long oil tiebacks architectures (50-100km) and related enabling technologies. The program is based on Eni most recent development projects (started up in the last 4 years) contemplating long tiebacks, new technologies implementation and experimental production periods conducted on those projects. Important field production data and measured performances on development projects have been a key to define the program. Wide ranges of tieback architectures and technologies have been studied. Technology providers and suppliers have been heavily involved. Technology validation and risk analysis approaches were used. Feed design is now ongoing regarding new asset development initiatives. The objectives are to reduce deepwater development costs increasing the distance between new assets and existing production hubs, shallow water areas or even connecting those assets to shore. A cost effective and flexible extra long oil tie back architecture proves to efficiently work on a wide range of applications and a wide range of design basis parameters. Key enablers are boosting, subsea power distribution, multicontrol communication, thermal management technologies, extensive work on reliability and availability and tailored operations procedures. Maturity levels and way forwards to a potential project execution will be discussed in the paper, including projected economics. Recent technology development, qualification and testing together with the experience matured on the most recent deepwater projects allow to seriously consider a "full subsea development approach" at long distances from existing hubs or from shore.