The present paper introduces a concept of a hybrid riser, Self Standing Hybrid Riser (SSHR), particularly in development for ultra deepwater around 3000 meters. Main problems faced in the initial definitions for design of such risers in the described scenario are discussed. Unique laboratory test with reduced model carried out in waves, current and riser top oscillation experiments in a very deepwater wave tank is shown. And, experimental results are shown and discussed, especially considering difficulties faced to carry out this experiment. Discussions are addressed in terms of vortex induced vibration (VIV) around buoyancy can, riser line pipe and flexible jumper.

The work was focused in the chase for alternative configurations that could resist to the high FPSO motions in the Brasil’s Pre-Salt harsh wave environment, and that could also be less compliant laterally when compared to the SLWR solution. A case study was taken where an infield 8 inch SLWR configuration has been taken for comparisons. After adjusting the SSWR (Steel Steep Wave Riser) main characteristics such as top angle, buoyant section length, buoyancy modules geometry and spacing, feasible configurations have been obtained. For a configuration to be considered as feasible, a set of verifications have been carried out including extreme events, wave fatigue, vortex induced vibration and installation. The verification was performed considering several riser top connection positions and azimuths along the FPSO riser support balcony. The interference with neighboring risers has been also taken as an important issue, but was taken solely for comparison with the SLWR configurations. The installation phase has been focused including the stages of bottom connection, normal pipe lay and the connection at the FPSO. The main problems associated to the installation phase of the steep wave configuration were identified and addressed in the discussion presented. As the SSWR configuration has a fixed point at the sea bottom, two different solutions for this connection have been studied, and the final choice is described. The main differences between SSWRs and SLWRs, and the possible advantages of the SSWR configuration are discussed and a direct comparison is presented.

The ever increase of global demand for petroleum and natural gas brings needs to discover new petroleum fields. Particularly in the Brazilian coast, these discoveries are located on more and more remote areas combined with harsh and aggressive petroleum fluid production, such as the case of recently announced pre-salt petroleum fields. Development of offshore systems for field production in this scenario demands sophisticated and innovative technological solutions. It brings the necessity for developments of frontier technologies to make viable design of oil and gas production systems to be applied for ultra deep water depth applications. Production riser is a very critical component of most offshore petroleum production systems. Riser acts as a physical connection between subsea wells and floating production facility at the sea surface. It conducts the oil and gas production, and sometimes, fluid or gas for injection into the petroleum reservoir. Wellhead control commands are also guided between the floating platform and the subsea system throughout the riser system. In the literature, many different riser systems have been proposed and extensively discussed for ultra deep water applications. Among others configurations, Steel Catenary Riser (SCR) appears as a technically feasible and economically viable solution. This system is comprised with a free hanging steel pipe, suspended from the platform directed to the wellhead in a catenary shape. In ultra deep water, the riser weight itself commonly is the limitation for application of this type of riser system. Once it requires a much more expensive floating production platform with larger capacity. Furthermore, it also can cause high concentrated stresses in some regions along the riser structure. Catenary shaped risers with lighter material such as Aluminum seem to be a very attractive alternative due to the great riser weight reduction observed. The present paper describes and proposes procedures for the design and operation of petroleum production riser system for ultra deep water application to produce high flow rate of oil and gas in a typical pre-salt petroleum field offshore Brazil condition. Results and discussions are shown through comparisons for catenary riser systems composed by steel pipe and other kind of lighter material. Case studies are conducted for water depth up to 3000 meters by parametric analysis. Current and waves effects along with floating platform motions and riser geometries are analyzed in order to identify critical conditions and to depict feasible solutions.