Wave-equation migration velocity analysis for anisotropic models on 2-D ExxonMobil field data

Conclusions and future work

In this paper, we apply our anisotropic WEMVA algorithm to a 2-D slice of an ExxonMobil field dataset. The previous anisotropic model was built using all available datasets in the area: surface seismic, vertical and offset check shots and sonic logs. From the initial migrated image using the initial model, we observe upward moveout at large angles in the angle CIGs, which is consistent with the negative travel time misfits in the large-offset check shots. After 8 iterations of our non-linear anisotropic WEMVA iterations, we obtain a better subsurface image with flatter angle gathers and higher angle coverage.

The provided anisotropic model shows high spatial correlation between vertical velocity and Thomson parameters. Figure 8 shows a cross-plot among the parameters $v_v$ , $\delta$ and $\eta$ down to $1$ km. The scatter plot shows distinct differences on different sides of the fault. Assuming these differences are based on the local geology and lithology, we should include this information into our model-building process in future work, possibly as a preconditioning constraint suggested by Li et al. (2011).

3dexxon
Figure 8. 3D scatter plot for the anisotropic parameters $v_v$ , $\delta$ and $\eta$ .

Wave-equation migration velocity analysis for anisotropic models on 2-D ExxonMobil field data