Oil production in Brazilian pre-salt fields has already become reality and its production has been reaching successive records in recent years. The development of these areas has required a major technological development effort and the application of several innovative technologies successfully.
One of the most remarkable characteristics of the Brazilian pre-salt fields is the high flow rate obtained from the producing wells. For the development of production in the most recent giant fields of the pre-salt, the high flow rate wells encourages the use of larger diameter production lines, saving costs in subsea engineering. However, the increasing of the oil production and the presence of contaminants and high gas concentrations in the oil reservoirs are technological challenges that increase the complexity of the oil processing, allied to more strict environmental rules. The use of larger diameter lines also requires the use of SCRs (Steel Catenary Risers), economically more advantageous in relation to flexible lines in this scenario. However, the use of rigid lines requires a Floating Production Unit with low level of motions, which implies in a large unit, more expensive. The use of larger diameter lines also increases the oil production platform requirements, increasing the need for additional production plant area as well as the ability to withstand heavier process plants.
These features encourage the search for innovative solutions that maximize production by FPU and still offer economic advantages through economies of scale. Based on this scenario, it was developed a concept of Floating Production Storage and Offloading Unit called ULFPSO (Ultra Large FPSO), which is capable of supporting plants more complex than the current ones, with a larger weight and a larger footprint, coupled with the receipt of the production lines in a region less affected by the environmental loads, enabling also the use of SCRs for larger diameter lines. This paper presents the characteristics of this new concept and present preliminary analysis of its feasibility.
