Seismic Interpretation

Abstract

The whole purpose of acquiring and processing seismic data is to present it in a form that can be interpreted by an experienced geophysicist. This form, at least to the present, is predominantly seismic record sections, either stacked or migrated. A new technique has now entered into the seismic exploration business—three-dimensional (3-D) acquisition and processing. The reason that 3-D seismic recording is becoming important is that, in complicated areas or in areas where fine detail is desired, the 2-D method is just not sufficiently accurate. The only seismic lines that can be migrated correctly in two dimensions are the dip lines. Any raypaths that come from out the plane of the section are always located vertically beneath the CDP point on the stack section, and they will not be migrated to their correct position, as shown in figure 11.1, because with 2-D data, it is impossible to migrate into the third dimension. The reflection at about 2.0s on the 2-D data that is not present on the 3-D data comes from a structure 2 km out of the plane of the section.