Heimdal monitoring. 2: Comprehensive log-seismic calibration in using VSP data
- Elf Aquitaine Production, Pau (France)
Within the framework of Heimdal Monitoring a previous study on the feasibility from cores and logs showed that the effect of fluid movement was still distinguishable from P-impedance in particularly at seismic scale. Before using AVO attributes obtained from a detailed surface seismic inversion for a quantitative interpretation of fluid movement between two seismic surveys, it is necessary to perform a comprehensive log-seismic calibration. This paper presents the method used to perform this calibration. In the first part, Poisson`s ratio determined from logs is calibrated using P and S-velocities from VSP. In the second part, a full wavefield VSP inversion is used to perform an accurate well-surface seismic calibration. The full wavefield VSP inversion provides also a reference acoustic impedance log for the macro model required for surface seismic inversion. This acoustic impedance provided by the full wavefield inversion is comparable with the acoustic impedance computed from sonic and density logs but free of borehole disturbances and without problem of scale changes. Full wavefield VSP inversion also contributes to optimization of surface seismic processing. In the case of lacking sonic and density logs, the VSP inversion is another way to obtain impedance measurements.
- OSTI ID:
- 80224
- Report Number(s):
- CONF-941015--
- Country of Publication:
- United States
- Language:
- English
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