Utilising information from VSP data to improve reservoir characterisation

In this work we use VSP data to help solve practical exploration problems. In particular, we show how VSP<br>data can be used to quickly assess the response of various seismic attributes. Specifically, we use downgoing<br>energy to evaluate and relate anomalous behaviour of seismic attributes to changes in effective stress.<br>Selected attributes are then computed on up-going VSP energy using later arrival times and, if sensitivity<br>with respect to changes in effective stress is retained, they are subsequently computed on surface seismic<br>data. Such simplified VSP-based analysis enables quick and efficient qualitative assessment of variations in<br>lithology, geo-pressure, or other rock properties under investigation. We also discuss how multi-offset VSP<br>data can be used to speed up pre-stack depth migration (PSDM) of surface seismic data in areas where<br>anisotropy is non-negligible and typically not fully defined.