Comprehensive Prestack Seismic-to-Well Tie Using Data Combination for Better Seismic Reservoir Characterization

All quantitative Seismic Reservoir Characterization workflows rely on careful seismic-to-well ties. It turns out that many Quantitative Interpretation (QI) workflows consist in linear combinations of prestack seismic data such as rotations / projections of Near / Far angle stacks or AVO intercept / gradient in their respective cross-plot domains. More sophisticated techniques such as prestack seismic inversion designed to estimate acoustic impedance and Poisson’s ratio to be further used for facies classification have a quasi-linear behavior relative to their input. Some of these combinations may reveal quite unstable so that good seismic-to-well ties of their input may not be sufficient to ensure quality results.

It is proposed here to assess the quality of seismic input not only within its measurement range but also across a comprehensive range of linear combinations of the same input.

Examples will illustrate that:

-It may be hazardous to plug real data into a linear combination derived from synthetic data analysis only.

-When scanning real data for an appropriate combination that matches a given elastic well log or even when using constrained seismic inversion results, the outcome might not genuinely represent the said elastic parameter.