Integrated Processing of Borehole and Surface Seismic Measurements for Enhanced Well Tie and AVO Analysis

The Wisting discovery in the southwest Barents Sea is characterised by a shallow reservoir lying at as little as 250 m below the sea bed. At the time of this study three exploration wells had been drilled in the field. At the first two wells achieving a well tie between borehole and surface seismic measurements had proved challenging. At the latest well, the operators OMV acquired an extensive suite of borehole measurements including multi-azimuth Walk-Away VSP (WAVSP) and wireline sonic data to facilitate the well tie. Historically, borehole seismic and wireline acquired sonic data are processed separately to one another and to the surface seismic data with which they must ultimately tie. OMV chose to instead follow an integrated processing methodology with continuous calibration and validation of results across the different domains. This workflow results in consistent datasets which have been used to derive a 1D VTI elastic model of the subsurface at the well which ties all data across each domain. By processing both surface seismic and borehole data together in this manner a well tie has been achieved and a deeper understanding of key factors that influence well tie at the Wisting discovery has been gained.