Análise integrada de sísmica e poços da porção noroeste do bloco de Libra, bacia de Santos

Abstract

In the last decade, the discovery of pre-salt reservoirs has motivated exploration in the offshore basins of the Brazilian Atlantic margin. With these discoveries has come the need to better understand and characterize these reservoirs and their behavior. Santos Basin is one of the main oil and gas producers in Brazil. The basin contains part of the Brazilian pre-salt boundary, where large area with high production potential have been discovered, especially due to the excellent oil quality. The Libra Block is located in the northern portion of the basin, and is currently the main pre-salt exploration block. This project used 2D and 3D seismic data and well logs to perform an assessment of the prospect in the northwestern part of the Block. The workflow used for this study consisted of seismic interpretation, from well-tie to the mapping of the principle horizons. Seismic attributes were used to characterize the seismic facies and identify the carbonate reservoirs of the prospective play. Petrophysical evaluation of wells 2-ANP-2A-RJS and 3-BRSA-1255-RJS was performed in order to obtain the values of total porosity, water and oil saturation, and Net-to-Gross for the Barra Velha and Itapema reservoirs. In addition to this, the eletrofacies for these reservoirs were identified via the analysis of gamma ray, porosity and sonic logs. The calculated rock parameters and reservoir depth surfaces were then used to estimate the present oil volumes by running a Monte Carlo simulation. The total oil volume obtained is 7471.7 MM STB in place and 2410.5 MM STB of recoverable oil.