Innovative Gas Treatment Solutions for Offshore Systems

Libra Area has presented gas/oil ratio (GOR) and CO2 content higher than the typically found in other Pre-Salt fields. These characteristics can significantly increase the size and complexity of the gas processing plant (GPP), especially in gas export scenarios. More efficient gas treatment technologies and with the ability to handle high CO2 levels need to be developed to reduce footprint and weight, improving oil plant capacity. This paper presents two membrane technologies selected for evaluation: Carbon Molecular Sieve (CMS), a partnership with Shell focused on CO2 removal, and All Membrane Solution (AMSTM), a commercial Air Liquide solution that can optimize the GPP layout by replacing conventional processes used for contaminants removal. AMS aims to remove, not only CO2, but also other contaminants such as H2S, H2O, and heavy hydrocarbons. Both technologies promise to lower the CAPEX and OPEX while increasing the oil production capacity, leading to more economically attractive projects. The demonstrations will be carried out at Atalaia Experimental Nucleus (NEAT), which is a Petrobras’ center for gas technology assessment, located in Aracaju city, Brazil. Pilot-scale skids operating under Libra typical gas conditions will be used for technology assessment. CMS and AMS will be tested sequentially, the former expected to start in the second half of 2019 and the latter in the first half of 2020. For CMS technology, further tests on an industrial-scale prototype will still be needed afterwards, whereas for AMS, due to its higher technology readiness level (TRL), it is expected that it can be implemented just after the demonstration.