A complex 3D volume for sub-basalt imaging

Abstract

Thick successions of basalt and basaltic-andesite lavas flows were extruded during continental break-up and they cover pre-existing sedimentary basins often of interest for hydrocarbon exploration. With conventional seismic acquisition and processing methods, it is difficult to image both the internal architecture of the volcanic succession as well as the underlying sub-basalt structure. The use of synthetic data can help us to understand the poor sub-basalt imaging quality and to develop effective acquisition and processing approaches useful for real data. Moreover, non-seismic methods have been successful in improving understanding of overall geometries of sub-basalt targets. Therefore, integration of seismic and non-seismic data seems to yield promising results and needs to be explored further. From all these considerations, the necessity of a realistic 3D basalt model that would allow simulating realistic seismic and non-seismic data, on one hand to test seismic acquisition and processing techniques, and on the other to develop strategies for geophysical data integration into a common methodology to overcome the sub-basalt imaging problem. A complex 3D model was built adapting all the information available from interpretation of seismic data, log data, gravity data, and geological observation. Seismic and non-seismic synthetic data have been produced on the model. In this paper we present the methodology to develop the 3D model as well as the initial results from data simulations. The model and the data are available to the public, through the authors of the present paper.