3-D Seismic Stratigraphic Inversion Applied Toan Oilfield Offshore Of Angola

The integration of well log data, poststack 3-D seismic data and conceptual geological knowledge (structural and<br>stratigraphic) provides accurate information for reservoir modeling and improve the implementation of efficient well<br>developments planning.<br>Stratigraphic deconvolution aims at improving the resolution which is here of paramount importance (Brac et al,<br>1988). Seismic data gives indirect three-dimensional information about the reservoir properties that can be integrated<br>with well log derived information.<br>For seismic inversion approach the key wells from the area of study, were sonic and neutron-density log, were<br>edited and processed through careful petrophysical analysis. Geological markers near and at the reservoir levels for<br>these wells were also interpreted to calibrate the regional seismic interpretation.<br>The stratigraphic seismic inversion consists of calibrating to tie key geological intervals from the wells with the<br>seismic horizons to build a 3-D initial model, and finally going through the inversion procedure to match seismic<br>amplitudes by updating the acoustic impedance model.<br>The initial model, an 3-D acoustic impedance model, is buiding from the interpolation of well log information.<br>The inversion methodology is carried out in an time window. We use the trace amplitudes as the constraints. The<br>initial acoustic impedance model is modified through an iterative procedure until the seismic synthetics volume<br>generated from the updated model match the real seismic data. The end product of the inversion procedure is a 3-D<br>inverted acoustic impedance and associated reflectivity volumes.