FPSO: Tanks Optimization Design Approach

Brazil Campos Basin is under large offshore oil production activity. Many new giant oil fields are under development. Brazil has been using tankers ship converted as FPSO platform vessel. At this moment three FPSO are in final construction phase to be installed in Campos Basin. Many oil cargo tankers are transformed to work as FPSO. Although they are showing good characteristics, some problems are having been emerging. The turret design approach was used in the primary FPSO’s but recently the spread mooring system with rigid risers is also under installation in Campos Basin. New ideas about Floating Production Storage and Offloading (FPSO) system have been in focus since some projects started working in an appropriately FPSO design direction. This paper spotlights one of these ideas: the FPSO tankers arrangement as a possible optimization procedure. MARPOL rule is followed but an alternative procedure is suggested to consider vessel control under wave’s action and at the same time looking for stress minimization. The aim in this procedure is increase the operator capability. The idea is allow the FPSO operator change the load condition using ballast in segregated tanks assuring a more suitable vessel condition in waves. Stability, wave response, stresses and operation ability should be also merit functions in any optimization process. A box shape FPSO-BR is used to highlight the procedure application. Results are presented and conclusion pointed out.