Abstract
The Sapinhoá and Lula North-East oil fields were developed through pilot systems composed of satellite wells connected to spread moored FPSOs. Each of these developments needed to connect up to 45 lines coming from the wells to a single balcony at FPSO portside, not including gas export riser and its ESDV umbilical. It was expected variable levels of CO2 and H2S, posing the challenge to find a suitable solution that could endure the 27-year life of the fields in waters of 2140-meter depth and in the severe environmental conditions of the Santos Basin. To cope with these challenges, Petrobras and its partners (BG E&P Brazil and Repsol Sinopec Brazil, in Sapinhoá field, BG E&P Brazil and Petrogral Brazil, in Lula Field) decided to pursue a decoupled riser system solution, and to launch a "design competition" process, which ended up selecting the Buoy Supporting Risers (BSR) concept solution developed by Subsea 7.
This paper is divided in two main sections that represent the two main project phases. First, the Design phase where the BSR System is described, the need for careful physical and numerical modelling, the massive analysis of this complex new system is also presented. The second is the Installation phase, which was all backed up by a prototype tank testing performed in order to capture the in-place behaviour, and to generate the design input envelopes for all system components. It also describes the considerable installation engineering efforts led to solutions for the logistical problems associated with the sheer quantity, volume, size and weight of the foundations and top connector structures as well as for the installation itself in ultra-deep waters and in seas often characterised by bi-directional swells.
Design Phase
