The recent discoveries and development of the Pre-salt reservoir in Brazilian coast require a new logistical model for crew transportation and transhipment to the drilling and oil rigs due to the large distance from coast, harsh environment conditions and large amount of workers to be transported against the actual model adopted considering only transportation by helicopters in order to reduce overall costs. The adoption of a logistic model with maritime transportation in these scenarios could provide several advantages, however there are several challenges from the technical point of view in transhipment between ship-shaped vessels, that could represent a great limitation in terms of operational window. Previous works showed the feasibility of monocolumn platforms with an internal moonpool as a Logistic HUB [1], allowing the boat docking in sheltered conditions. This work shows an overview of the model testing of a semi-submersible with an internal dock and the comparison of the free-surface elevation and RAOs (Response Amplitude Operators) between experimental results and potential flow computations. The tests were performed for 5 headings considering 10 regular, 5 irregular and 1 transient waves under a single draft and 5 different devices to reduce wave energy in the interior region.

The standardization process was initiated nearly a decade ago under a thriving scene of the oil industry. At that time, Petrobras had already had a long experience designing, contracting and participating in offshore production units. This vast experience showed that eventual optimization obtained with tailor made solutions tended to lose attractivity, regarding schedules and costs, when compared with identical projects. This perception motivated a movement towards standardization and a radical change in design philosophy. This initiative has proven to be applicable to a wide range of crudes and several units have been contracted since. The first standardized projects developed by Petrobras, were the P-58 and P-62 FPSOs, two similar units to operate at Baleia Azul and Roncador fields, respectively. These units are operating with very good results. Since then, eight "Replicants" were contracted to Brazilian shipyards and the first unit should be producing next year. Despite the success of standardization, in current scenario of cost reduction, incrementing the capacity of new FPSO units is a major option to be evaluated. In this context, this paper will present Petrobras strategy towards EPC of its FPSOs and how cost reduction is planned. Future trends will also be discussed.

Monocolumn platforms are usually considered an alternative concept for drilling and offshore production unit designs. This concept could provide high stability, small motions and also storage capacity. More recently, it was considered for a logistic hub platform design. The use of this concept with an opening for boat docking seems to provide a feasible solution for the people transfer in harsh environments, especially in areas like pre-salt Brazilian offshore fields, which are also very far from the coast. Although the helicopter technology has been improved in recent years to attend transport requirements from shore to the platforms, the use of a hub platform at sea still shows some economical and operational advantages, related to the conventional operations. Although the sheltered area provided by the interior of the monocolumn platform seems to solve the transfer problem in harsh environments, the hydrodynamic behavior of the moonpool became a problem to be solved during the feasibility studies of the concept, since the moonpool water column elevations tends to be resonant in special cases. To deal with this problem, some attempts were done to absorb the wave energy inside the moonpool and eliminate its resonance, achieving the desired level of absorption. This work shows the attempts and the results obtained, which has proven the feasibility of the concept.

The offshore oil fields exploitation, especially giant fields in the Santos basin, brings with it demands for systems capable of operating at ultra-deep waters, with high capacity production wells and high gas/oil ratio (GOR) with large amount of contaminants. In this scenario, steel catenary risers (SCRs) offer the simplest, most robust and lowest cost solution. However, due to its rigidity compared to flexible risers, this solution is affected by the high dynamic forces imposed on the top of the riser, in consequence of the FPSOs large vertical movement in waves, making difficulties on their application in conventional FPSO hull units. This dynamic problem is caused by environmental conditions of the region, which are harsher than those observed in the Campos Basin. The reservoir characteristics described above demands high-capacity oil & gas process plants, larger than those used today in the Brazilian offshore. Initial estimates show that these plants require a much larger deck area than conventional platforms and, more than that, a greatest breadth of the vessel. This paper presents the ULFPSO (Ultra Large Floating Production, Storage and Offloading) concept, developed to satisfy such conflicting requirements. The design process, including the preliminary sizing, physical scale model test and the hull form optimization are discussed and presented in this paper based on a high-capacity process plant case study.

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