3-D structural inversion applied to seismic data from offshore Indonesia
The third 3-D structural inversion case study is from offshore Indonesia; it involves a 3-D survey that covers an area of nearly 150 km2. The surface area is roughly a rectangle with dimensions of approximately 15 km in the inline direction and 10 km in the crossline direction. Survey statistics include more than 15 million traces recorded and 480 000 stacked traces. The nominal fold of coverage is 32, the inline trace spacing is 12.5 m, and the crossline trace spacing is 25 m. Figure 7.4-22 shows three inline sections from the volume of 3-D prestack time-migrated data from this 3-D survey.
Figure 10.7-13 Depth structure map of the base-Zechstein target horizon using three different procedures: (a) coherency inversion with vertical velocity gradients accounted for, (b) stacking velocity inversion with vertical velocity gradients accounted for, and (c) stacking velocity inversion without vertical velocity gradients accounted for.