Regional and Reconnaissance Use of 3-D Data
Three-D seismic coverage is now very extensive in both land and marine environments, making practical the regional and reconnaissance use of 3-D data. This has led to more exploration applications of 3-D surveys. More than 10 years ago there was a type of “Exploration 3-D” which involved widely spaced acquisition and interpolation in processing. Today all 3-D data are properly sampled and data acquisition is fast and highly efficient, particularly at sea.
Figures 11-1 through 11-4 show time slices from 1600 sq. km. of speculative 3-D seismic coverage in the Gulf of Mexico, and this is only a small portion of the total data available. The four salt domes change with depth and the structural complexity increases. Regional studies of salt tectonics are made possible with this kind of display, and time slices are key in revealing the spatial patterns of faulting. Coherence data displayed in time slices often provide improved visibility of fault patterns. Figure 8-24 shows many faults clearly delineated in coherence over an area of 1400 sq. km.