Carbonate reservoir characterization using seismic diffraction imaging

Khuff

Seismic diffractions in the Khuff model highlight two strata with increased heterogeneity that are not immediately apparent in the conventional image.

If we examine the Khuff seismic diffraction image, Figure 11b we notice that amongst a chaotic diffraction background, there are two upward sloping linear features which intersect the left side of the image cube's inline axis near depths of 3040 m and 3065 m, and the right side of the image cube's inline axis near 3030 m and 3055 m. These layers correspond to the heterogeneous zones in the acoustic impedance model, Figure 2c. These heterogeneous regions are lost in the reflection image, Figure 11a, which features a series of parallel reflections.

Examining the diffraction image cross sections, Figures 12b and 13b provides a clearer view of the heterogeneous layers visible in the acoustic impedance cross sections, Figures 12c and 13c, which remain less apparent in the corresponding conventional image cross sections, Figures 12a and 13a. Although many of the features in the Khuff model are below diffraction resolution, the different scattering behavior and intensity is clearly helpful for detection of heterogeneous regions.

The heterogeneous strata are also apparent in the Khuff seismic diffraction data, Figure 10b. These strata, located where at the left edge of the cube's inline axis near Time 1.6 s and Time 1.618 s slope upward to the right, and are rich in hyperbolic diffractions.

We can conclude that applying seismic diffraction imaging methods on the Khuff model enables us to more accurately determine regions of heterogeneity in a reservoir-scale model.

Carbonate reservoir characterization using seismic diffraction imaging