F.P. Figueiredo

1D Organic Facies Modelling of the Camamu-Almada Basin

The distribution of organic carbon in a basin depends on the interaction of the input of organic matter into the basin and its corresponding lithology distribution. Different types of organic material have different sizes and are thus distributed differently according to their settling behaviour. The OF-Mod 1D tool was developed in order to model organic facies based on different stratigraphic and geochemical parameters. In this study, the Camamu-Almada Basin is analysed using this tool. This basin had its origin through extensional processes during the breakup of Gondwana. During the rift stage, there were ideal conditions for deposition of organic-rich shale on lacustrine environment. Four different intervals were defined in this depositional system, but only two represent the source rock of the current petroleum systems. The results indicate that these two formations are mostly composed of kerogen of type I. Even though there is only one type of kerogen, it was possible to distinguish two different categories of organic facies: AB for Morro do Barro formation; and B for Rio de Contas formation.