GHG Emissions quantification project completed at FPSOs in Brazil

MODEC and JGC Corporation have announced the completion of a project to measure and quantify emissions of methane and other greenhouse gases (GHG) from floating production, storage, and offloading systems (FPSO) off the coast of Brazil, chartered and operated by MODEC1. 

This represents a significant milestone for both companies, and this is the first time that Japanese companies gain precise insights into the amount of major GHG emissions from methane, nitrous oxide, and hydrofluorocarbons (HFCs) from active FPSOs.

Project background

In its Mid-term Business Plan 2024-2026, MODEC states that one of the initiatives under Vision 2034 is to be the world's best FPSO builder and operator, achieving the smallest carbon footprint alongside safety and high uptime. As a first step in decarbonizing the MODEC’s core FPSO business, MODEC is actively involved in measuring and reporting FPSO GHG emissions. In addition to carbon dioxide emissions, this project also addresses methane, nitrous oxide2, and HFCs, which have a very high greenhouse effect.

JGC Corporation is engaged in mitigating GHG emissions from oil and gas production facilities in part by leveraging technical engineering expertise and extensive plant construction experience to provide HiGHGuard® GHG emissions measurement service for methane and other GHGs using the MRV3 methodology. In the absence of globally standardized measurement methods, JGC offers highly reliable measurement and quantification in line with plant operations and these conditions, as well as low-carbon/decarbonized solutions based on this knowledge.

Building upon this expertise, MODEC and JGC Corporation have decided to combine their strengths to implement a project aimed at accurately identifying methane, nitrous oxide, and HFCs emissions from FPSOs.

Project overview

A quantification of emissions of the three GHGs – methane, nitrous oxide and HFCs – was carried out from July to September 2023 at two MODEC-chartered FPSOs off the coast of Rio de Janeiro.

While the need for emission prevention measures, particularly for methane, has increased in recent years, methane emissions vary widely from facility to facility, and because desktop calculations with common coefficients are not accurate enough; there has been a strong international recommendation that emissions should be determined by actual measurements. 

Therefore, MODEC and JGC selected two methods of on-site measurement: a bottom-up approach using hand-held sensors and infrared cameras, and a top-down approach using drones (See Figure. 1 below). The bottom-up approach measures approximately 15,000 potential methane emission points in the FPSO, and the latter approach captures the methane potential of plant-wide emissions from flying the drones around the FPSOs.

Some examples of project results are as follows:
　・ Determination of methane and other GHG emission levels with much greater precision than conventional desktop calculations.
　・ Establishment of a highly reliable methodology for measuring methane emissions by combining multiple measurement technologies.
　・ Identification of individual methane emission points on FPSOs, with results leading to specific emission prevention measures.