Viabilidade Da Sísmica 4D Em Um Campo Terrestre Brasileiro: Enfoque De Rochas

We made a feasibility study for the application of the time lapse seismic technique on a shallow onshore Brazilian field, at<br>the Potiguar Basin, Rio Grande do Norte. This anonymous but real fluvial reservoir are now being subjected to vapor<br>injection, which is a good production technique for seismic monitoring. Seismic velocities measurements on core<br>samples and reservoir fluids, as well as fluid substitution on the available well log data, were used at the preliminary<br>stage of the feasibility study in order to quantify the velocities and impedance changes that the reservoir would<br>experience as a function of temperature, fluid saturation and pore pressure. Biot-Gassmann equations were combined<br>with the reservoir thermal simulation in order to construct a velocity and impedance model for the seismic modeling. It<br>was found that acoustic impedance changes as large as 40% would occur and that it should be resolved by the high<br>resolution 3D seismic. The initial and final seismic models and it’s updated versions shall help the reservoir geophysicists<br>on the interpretation of the real time lapse seismic data, which may provide insights on the fluid flow behavior and<br>reservoir heterogeneities.