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AcousticImpedance near offset

I A = e2 R(0 )dt

I E = e2 R()dt

IA = VP

IE = f(,VP ,VS, )

ElasticImpedance

far offset

(see, for example, Mukerji et al., and Connolly, both in SEG meetingextended abstracts 1998)

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Acoustic Impedance Elastic Impedance

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Cross-plot of elastic impedance at 30o vs. acoustic impedancefor different lithofacies and fluids.

North Sea Example

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Far offset stackNear offset stack

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Near offset acoustic impedance vertical sections

Far offset elastic impedance vertical sections

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Near offset acoustic impedance time slices

Far offset elastic impedance time slices

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Vertical sections showing lithofacies classificationbased on linear discriminant analysis.

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IsoProbability Surfaces

Blue at top shows 90% probability of shale. Red (middle) shows 80%probability of oil sand.

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Classification success rate at well.

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Classification success rate at wells.

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Cross-plot of elastic impedance vs. acoustic impedance.

Gulf of Mexico Example

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Cross-plot of elastic impedance vs. acoustic impedance.

Gulf of Mexico Example

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Seismic inversion in conjunction with statistical rockphysics classification to map 3D spatial distribution

of facies and fluids.

Near and Far offset impedances (AI-EI).

Obtain not only the most likely facies, given theinherent natural variability, but also quantify theuncertainty.

Framework for an efficient strategy to optimallycombine statistical techniques with physically basedseismic-to-reservoir properties transforms.