Print this pageFacies Simulation and Seismic Inversion Techniques Applied to a 2D Petroleum System Modeling in the Espírito Santo Basin
The building of an accurate geologic input model is crucial for the performance of reliable basin and petroleum systems modeling and its application as a tool to assess geologic risk in petroleum exploration. The low resolution of geologic models, particularly when referring to the representation of lithological and petrophysical attributes, hampers a more accurate simulation of petroleum system processes, especially HC migration and entrapment. Improvements in computer processing capacity allow the simulation of large highly-detailed models, enabling the incorporation of the numerical inferences from facies simulation and seismic inversion techniques. This work presents the use of these two techniques in the definition of facies distribution and characterization in a 2D basin and petroleum system model of the Espírito Santo Basin.
Once seismic interpretation of the main units was completed, the already defined stratigraphic units were subdivided and its facies distribution was defined according to facies simulation. This step started with the seismo-facies definition that was then used to populate a discrete facies model according to its stochastical distribution. The petrophysical properties of these facies were assigned based on the porosity function obtained with well data.
Exclusively within the stratigraphic unit of most interest - The Creataceous - the seismic inversion study was carried out making use of pre-stack seismic data, petrophysical and geological information from well data and rock physics models. This step allowed the facies classification in a seismic volume, in the same resolution as the stacked seismic data, based on neural network inferences of rock physics properties.
After assembling all the gathered information, the basin and petroleum system modeling proceeded as usual. It is important to remark the need to integrate professionals specialized in each of the above-mentioned disciplines in order to build a consistent model.
The presented workflow allowed the construction of a detailed model, taking into account all the available data and the newest technology. As a result it was possible to better simulate migration in the central part of Espírito Santo basin, achieving more realistic migration paths and accumulation distribution. It was also possible to better preview rock behavior, such as pore pressure and temperature.
AAPG Search and Discover Article #90100©2009 AAPG International Conference and Exhibition 15-18 November 2009, Rio de Janeiro, Brazil