Seismic attributes analysis of a permo-porous system in neobarremian-eoaptian carbonates reservoirs – Campos Basin (Brazil)

Abstract

The geological complexity of carbonate reservoirs formed by coquinas at the rift section of Campos and Santos basins has been directing the studies aiming efforts to understand this type of reservoir, even in an analogue form. The application of this analysis intends to help the understanding of the main physical properties distribution and the geometric permo-porous system associated to the potential reservoir levels located in carbonate reservoirs formed by coquinas in the Upper Barremian – Lower Aptian in Campos Basin. The method uses seismic attributes generated from 3D seismic and their correlation with the petrophysical property as porosity from well logs. Considering two pre-defined reservoir levels (CI-A and CS), the correlation between the main physical properties (well logs and petrophysical analysis) and the seismic attributes of amplitude and sweetness showed correlation coefficients ranging from R2≥0.7 to R2≤0.92. This integration of this petrophysical analysis with the seismic interpretation concludes that the porosity distribution at the reservoir level CI-A has higher influence of the tectonic structure, when compared to the reservoir level CS, with the best porosities (8% to 24%) following the main structures with NW-SE direction. The porosity values from reservoir level CS has a homogeneous distribution and reduces porosity towards South-Southeast, following the thickness decrease of these coquinas reservoir level.