Carlos Abreu
Senior Advisor
PETROBRAS Petróleo Brasileiro SA
Carlos earned a B.S. in Geology at Universidade Federal do Rio de Janeiro - UFRJ, Brazil, a M.SC. in Reservoir Geoengineering at Universidade Estadual de Campinas - UNICAMP, São Paulo - Brazil, investigating the anisotropic response of fractured reservoirs, and a Ph.D. in Reservoir Geophysics at INPL/Université de Nancy, France, developing geostatistical tools to condition time-lapse seismic analyses workflows. After joining Petrobras in 1985, he has worked in a broad range of exploratory activities in both onshore & offshore seismic data acquisition, processing and interpretation. In 1992, Carlos joined the Reservoir Department, and has been involved with major Campos and Santos basins oil & gas fields initial development projects since. As a Senior Advisor, Carlos coordinated inumerous internal and external applied R&D projects involving deepwater seismic acquisition technologies, seismic reservoir monitoring, uncertainty analyses & quantification, and complex Pre-salt carbonatic reservoirs advanced geomodelling and characterization. Carlos has joined the Buzios asset team in 2023, focusing on the implementation of the Life of the Field seismic technology.
Participates in
TECHNICAL PROGRAMME | Primary Energy Supply
The discovery of the Pre-salt province in 2006 in Santos Basin, southeast Brazil, unveiled significant hydrocarbon reserves in ultra deep-water offshore carbonate reservoirs. The Buzios field, identified by the wildcat well 2-ANP-1 and currently the largest known commercial oil field in ultra deep-waters worldwide, features a substantial column of carbonate rocks containing light oil (27-30º API), driving innovations in geology and geophysics (G&G) modeling and advanced drilling technologies. A crucial aspect of Buzios's Director Plan is maximizing recovery through a comprehensive data acquisition strategy, use of water and water-alternate-gas (WAG) injection methods and remotely operated intelligent completion valves (ICVs), as well as incorporating seismic monitoring throughout the field's lifecycle. The primary oil extraction mechanism is the solution gas drive, supplemented by secondary recovery methods using WAG injection. The drainage strategy positions producers in structural highs, with peripheral injection wells in the flanks.
Modeling 4D signatures:
Uncertainties in geophysical modeling of the complex carbonate reservoirs in Buzios emphasize the need for advanced marine acquisition technologies. The first Ocean Bottom Nodes (OBN) survey recorded in Buzios and completed in 2019, was the largest survey globally at that time. Selecting suitable long-term seismic monitoring technology requires a multivariate approach, considering rock and fluid properties, economic analyses, water depths, subsea layout complexity, and the number of scheduled monitoring surveys, to identify those that maximizes seismic data repeatability. A critical aspect is the expected 4D seismic signature, dependent on the rock-fluid system and selected recovery mechanisms. The injection program aims to enhance sweeping efficiency and compensate for pore pressure decreases due to significant oil production rates. Petroelastic modeling studies have provided synthetic seismic responses related to anticipated WAG and water injection conditions. Findings highlighted challenges in obtaining reliable 4D signatures, indicating complex interactions between injected fluids and reservoir matrix.
Monitoring Surveys and Value of Information (VoI):
To evaluate the optimal timescale for future seismic monitoring campaigns and their ability to capture rapid reservoir changes, Petrobras conducted field tests after its first Nodes monitor campaign. The VoI metric assesses the economic benefits of acquiring additional information for decision-making, comparing acquisition costs against their potential impact on reducing uncertainty. Benefits include optimizing well placement, improving production rates, identifying poorly swept zones for infill opportunities, and mitigating geomechanical risks. Successful implementation of the Life of the Field Seismic (LoFS) project in Buzios relies on high-quality seismic monitoring data, efficient processing, and rapid updates of numerical simulators.
Conclusions:
Opportunities from the LoFS project in Buzios depend on high-quality seismic monitoring data for G&G model integration. Maximizing investments requires efficient processing and swift updates of geological and numerical simulation models, enhancing well placement predictability, understanding fluid pathways, and mitigating geomechanical risks.
