Carbonate reservoir characterization using seismic diffraction imaging

Ordovician

Seismic diffraction imaging improves the resolution of voids present in time slices relative to seismic reflection imaging. Examining the zoomed conventional and diffraction images from 0.55 km depth, Figures 7a and 7b, we notice that diffraction imaging enables us to tell that what appears as single shapes in the reflection image are actually superpositions of multiple void responses. If we examine the features centered at inline 8.85 km, crossline 4.5 km; inline 10.15 km, crossline 4.25 km; and inline 10 km crossline 6.5 km in the conventional image, Figure 7a, we see responses that may appear to be single voids. In the corresponding diffraction image, Figure 7b, these shapes separate into joined rings, which define the edges of two overlaying voids.

The deeper slices from 0.7 km depth illustrate how diffraction imaging increases void edge resolution. If we compare the voids visible in the zoomed image (Figure 9), using the diffraction image we are better able to tell where void edges are located; they are marked by the reverse of seismic polarity. Additionally, diffraction imaging enables us to see that the feature centered at inline 1.65 km, crossline 12.25 km is actually a superposition of two nearby voids.

Therefore, using seismic diffraction imaging methods on the Ordovician model we are able to better distinguish between overlaying voids in depth slices, and better spatially locate void edges.

Carbonate reservoir characterization using seismic diffraction imaging