Authors: Marco Cocchi – Researcher – Campus Bio-medico University of Rome
Leone Mazzeo – Researcher – Campus Bio-medico University of Rome
Oil & Gas industries have moved in deeper, more remote and technically demanding regions in the last 30 years. With increasing technical complexity of the extraction facility, the fixed cost of the Oil & Gas upstream complex also increases, but in the persistent lower-for-longer price environment there is continuing pressure to develop these fields safely while reducing CAPEX and OPEX costs.
FPSO technology seems to be promising in offering a flexible solution to explore remote Oil fields while in maintaining competitive costs. Nonetheless, Semisubmersible units, SPAR platforms and tension-leg platforms (TLPs) are also common in deepwater regions. TLPs, in particular, find application in up to 1,500m-deep water wells, but FPSO has the advantage to offer the required onboard storage capacity and offloading capability without employing a separate storage vessel or infrastructure.
The high dynamic motion, generated by the rough sea condition to which FPSO units are exposed when operating in remote sea areas, makes the Riser System design more challenging. In fact, it plays a fundamental rule in determining the feasibility of the extraction of hydrocarbons exploiting remote region resources. Thus, the development of a low-motion FPSO enables the utilization of conventional riser systems (such as steel catenary risers and top-tensioned risers). The use of conventional riser technologies, is also able to improve the life-cycle and reliability of a FPSO facility: the realization of a simple and effective installation (by the means of an additional facility structure) that is able to oppose to the high dynamic forces that rough sea environment exerts on the floating structure, is a technological step change, needed to open up less accessible or economically cost-prohibitive fields.