An Innovative ML Methodology for Property Modeling (EMBER): A Case Study in Buzios Field, Brazil

Abstract

Abstract The application of the Embedded Model Estimator (EMBER) petrophysical modeling algorithm allowed for the determination of effective porosity and permeability in the presalt carbonate reservoirs of the Barra Velha Formation located in the Buzios Field, Santos Basin. This sophisticated approach was necessary due to the complex and heterogeneous nature of these reservoirs, which posed challenges for traditional geostatistical methodologies. Effective porosity was modeled using a combination of secondary variables including a facies model, a stratigraphic seismic attribute (acoustic impedance), and a structural seismic attribute (local flatness). Permeability was modeled using the most accurate simulation results obtained for effective porosity. Our findings indicate that the average effective porosity and permeability values were 0.10 v/v and 440 millidarcies (md) respectively, indicating favorable reservoir quality across the entire study area. An analysis of the reservoir properties revealed a vertical trend characterized by a basal section and uppermost section exhibiting high effective porosity and permeability, while an intermediate section displayed lower reservoir properties. The lower section of the formation exhibited greater continuity and is inferred to be the most favorable reservoir interval. The correlation between the modeled results and the blind-test ANP-1 well upscaled properties was found to be significant, demonstrating the predictive capability of the employed algorithm. Furthermore, the EMBER simulations successfully preserved the distribution of upscaled well log properties, further validating the algorithm's accuracy. Finally, an analysis of conditional distributions indicated that the estimation of effective porosity in the basal section of the Barra Velha Formation is subject to higher uncertainty. Therefore, although this interval is considered to possess the most favorable reservoir characteristics, caution should be exercised when making decisions regarding this specific reservoir section.