synthetic seismograms
The final product of our step-by-step procedure to create a seismic model is a synthetic seismogram or a synthetic seismic section. The use of edited or modeled log data as input is highly recommended. A few examples are shown below, illustrating the enormous variety of presentation styles that might appear on your desk.

The synthetic below demonstrates the serious mismatch that can occur when log editing is omitted. The strong events at the top of the Cretaceous and in the Lower Jurassic are artifacts of bad hole condition affecting the sonic log. Small mis-ties are caused by these problems and other rock alteration. Since I personally made this synthetic in 1969, I feel comfortable criticizing it now, but I thought it was a good match at the time. Today, it would be inadequate and could be improved.


 

Synthetic seismogram with corresponding marine seismic section

Synthetics and seismic models can also include multiple reflections or shear wave models from shear wave sonic logs. Normal moveout is rarely modeled on a synthetic, but it might be useful to identify reflectors on raw seismic records.

Synthetic seismograms with multiple reflections

Synthetic seismograms from shear sonic data

Synthetic model of normal moveout

View the Case Histories in the next Section to see some really well done seismic models.