Integrated seismic and well log data conditioning for seismic inversion

Abstract

Seismic data and elastic log conditioning are regularly carried out in preparation for seismic inversion. When the seismic quality is uncertain and the well data are sparse, poor or missing, an integrated and iterative workflow must be applied to provide a satisfactory level of confidence prior to inversion. A dataset from the Gulf of Thailand provided a challenging testing ground. The seismic data were old, noisy, and had limited offset. Only two wells lay within the seismic volume, one vertical with significant washouts and one highly deviated with limited log coverage. No shear velocity measurements were available in either well. Using inversion at the wells for guidance and offset wells for calibration, seismic data conditioning and well log synthesis and editing were iteratively adjusted to optimize the well tie. Significant increases in correlations between the processed well logs and inverted data were achieved whilst honoring elastic log trends and relationships observed in the offset wells. Based on these improvements combined with observations of the seismic data, inversion products and quick-look interpretation results in section and map view, confidence in the seismic data as fit for inversion and reservoir characterization was achieved.