Maximizing the use of existing topside facilities is an attractive approach to reduce project CAPEX and therefore unlock new reserves. However, as the tieback length to the host increases, technical and economic challenges arise. These include flow assurance, and costs of the umbilical and flowlines which inherently increase with length. These aspects, together with others independent from the length, such as power and space availability, have a significant impact and could result in making the project unfeasible or uneconomical.
Technologies developed in recent years, or in their final stage of qualification, play a significant role, not only in solving the technical challenges, but also in finding cost-effective configurations, either by reducing and/or staggering capital and operational expenditures or by extending reserves recoverability or also by reducing significantly the risks associated with a development.
In order to appreciate these advantages, different configurations have been outlined starting from those allowed by the conventional technologies and comparing them to the ones enabled by the new technologies. Actual advantages of each technological "bricks", considered alone or in synergies, depend on the specific projects and can be identified in a timely manner thanks to early engagement of Contractor in the architecture and associated pricing of subsea tiebacks.
The paper will present a platform of technologies, their maturity status and how they can be integrated in novel architectures in an economic manner. Such technologies include:
Distributed and local heating
Subsea water treatment and injection
Subsea chemical storage and injection
All electric control system
Local power generation