PS results

Figure  shows the PS migration result, using the updated P velocity model and the given S velocity model. Figure  shows three angle domain common image gathers for this migration result.

 

psmiga Figure 6 PS migration result with the updated P velocity model and the given S velocity model.

 

psmigb
Figure 7 PS angle domain common image gathers. They corresponds, from left to right, to a lateral position of 2000m, 4000m and 5400m. Observe the significant residual curvature.

Figure  presents the residual migration results keeping the $\rho_p$ value as 1, i.e, no changes in the P-velocity field, and a $\rho_s$ value of 0.98. Figure  shows the angle domain common image gathers for the residual migration process. These angle gathers are at the same position as in Figure , however, they correspond to $\rho_s$ values of $\rho_s=0.98$ $\rho_s=0.99$ and $\rho_s=1.02$.

 

pssrm Figure 8 PS Stolt residual migration result

 

pssrm2
Figure 9 PS angle domain common image gathers after Stolt residual migration for converted waves. They are at the same location as in Figure  and corresponds to, from left to right, $\rho_s=0.98$, $\rho_s=0.99$ and $\rho_s=1.02$.

The $\gamma_0$ value used for the PS residual migration is constant for the whole section, with a value of $\gamma_0=1.728709$.The $\gamma_0$ value was chosen at a depth of 1900m, which is the estimated depth of the Alba reservoir, and at the center of the section.