Modern Solutions to Pitfalls in Seismic Interpretation
One of the most useful books available to exploration geophysicists is the monograph by Tucker and Yorston (1973), Pitfalls in Seismic Interpretation. It starts with a biblical quote from Ecclesiastes 10:18: “He that diggeth a pit shall fall into it.” This implies that many of the traps found in seismic data are not always of the hydrocarbon variety. These traps are misinterpretations of what we see in the seismic section. They are sometimes of our own creation. Many can be cured by processing.
interpretation of seismic time sections as if they were depth sections, thus failing to recognize velocity effects
interpretation of 3D effects on a 2D seismic section
failure to recognize that some seismic arrivals are not related to the desired geologic structures but may be caused by “noise”
Many of the pitfalls originally described by Tucker and Yorston (1973) can be obviated with modern acquisition and processing methods. For the three pitfall types, modern preventive methods include the following:
If misinterpretation of time sections is a problem, we should convert data to a depth section. This can be done with depth migration. Prestack depth migration is a great tool, as described in later chapters, but it does require accurate velocity information. A good example is shown in Figure 1. From the time section in Figure 1a, it appears that the top of the salt reflector is discontinuous. This is largely the result of velocity effects.
Figures & Tables
Fundamentals of Geophysical Interpretation, SEG Geophysical Monograph Series No. 13, is a practical handbook for the petroleum geophysicist. Fundamental concepts are explained using heuristic descriptions of seismic modeling, deconvolution, depth migration, and tomography. Pitfalls in processing and contouring are described briefly. Applications include petroleum exploration of carbonate reefs, salt intrusions, and overthrust faults. The book includes past, present, and possible future developments in time-lapse seismology, borehole geophysics, multicomponent seismology, and integrated reservoir characterization.