Energy optimization of an FPSO operating in the Brazilian Pre-salt region

Ali Allahyarzadeh-Bidgoli ( University of São Paulo)

CHALLENGE - FPSO (Floating, Production, Storage and Offloading) units are used for primary petroleum processing. The FPSO units have a technical advantage for short-lived well exploration and for remote marginal fields, where building a pipeline is cost-prohibitive. The goal of this study is to present an optimization procedure to find the best operating conditions of a primary petroleum platform processing crude oil with high gas-oil ratio (GOR) and moderate CO2 content.

SOLUTION - Seven input parameters related to operating pressures of plant are selected for the optimization procedure aiming to minimize the total fuel consumption (FUE) of the FPSO. For the optimization procedure, the processing plant of the FPSO is modeled and simulated by using Aspen HYSYS. After the thermodynamic convergence is achieved, fuel consumption and additional outputs are picked up by integrating  modeFRONTIER software. The objective function (fuel consumption – FUE) is then evaluated by the Genetic Algorithm.

BENEFITS - modeFRONTIER allowed to reach the optimum operating condition, achieving  a reduction in fuel consumption by 4.6%. Moreover, because of the fuel consumption optimization, a significant reduction by 6.3% in the power consumption of the plant and an improvement in the recovery of the volatile components were verified, in comparison with the baseline case.