The Brazilian offshore pre-salt cluster is one of the most important recent discoveries of hydrocarbon resources in the world. These fields normally present high CO2 content (more than 10%) and also high Gas Oil Ratio (GOR), thus might limit the oil production in the convention FPSOs project due to the capacity and complexity of gas processing plant. These conditions lead to application of alternative processes for gas treatment in offshore environment, such as molecular sieve for dehydration, fixed bed for H2S removal and CO2 removal membranes. Besides, due to high flow and high pressure drop involved in the treatment section, an increase in the number of equipment, such as compressors, heat exchangers and scrubbers are needed in order to reach high pressure values necessary for the CO2 reinjection into production zones for Enhanced Oil Recovery (EOR). proposes.
This objective will also contribute to increase complexity on the gas processing plant since it must deal with expected variations in GOR and CO2 content in natural gas during field lifetime. Petrobras and partners have been working, since 2008, with the objective to increase performance of existing processing and compression technologies and also supporting application of new ones (technological gaps) that can result in overall improvements in CAPEX and OPEX, such as: nano-sized zeolites for dehydration, new metal oxides for H2S removal with high capacity under influence of CO2, new material for membranes (ceramic and carbon tubes) and dense phase CO2 separation. The aim of the combined use of such iniatives is footprint and weight reduction, higher efficiency, less energy consumption with modular design. The purpose of this paper is to present the actual strategy for developing offshore gas process in Brazil, emphasizing the different technological gaps identified and the consequential road maps that are being pursued for the new units to be designed.
