What is a synthetic seismogram used for?
In earthquake seismology, synthetic seismograms are used either to match the predicted effects of a particular earthquake source fault model with observed seismometer records or to help constrain the Earth’s velocity structure. Synthetic seismograms are generated using specialized geophysical software.
How to create synthetic seismogram?
The steps necessary to create a synthetic seismogram manually are described below:
- Edit the sonic and density logs for bad intervals.
- Calculate vertical reflection times.
- Calculate reflection coefficients, Ro .
- Combine the last two items to create a reflection coefficient time series.
What does a sonic log measure?
The sonic or acoustic log measures the travel time of an elastic wave through the formation. This information can also be used to derive the velocity of elastic waves through the formation. Its main use is to provide information to support and calibrate seismic data and to derive the porosity of a formation.
What is Sonic slowness?
ADVERTISEMENT. A sonic log is an acoustic log that emits sound waves which start at the source, travel through the formation, and return back to the receiver. The travel time from the source to the receiver is called slowness and as a result sonic logs are sometimes referred to as sonic slowness logs.
What is the principle of density log?
The density log measures electron density by detecting gamma rays that undergo Compton scattering. The intensity of scattered gamma rays is proportional to electron density. Electron density is the number of electrons in a volume of the formation. Electron density is proportional to bulk density.
How is a synthetic seismogram used in science?
The synthetic seismogram (often called simply the “synthetic”) is the primary means of obtaining this correlation. Velocity data from the sonic log (and the density log, if available) are used to create a synthetic seismic trace.
What kind of data is needed for synthetic seismic trace?
As already stated, the primary well data required to generate a synthetic seismic trace are sonic log (inverse of the sonic log is the acoustic velocity) and density log. Check shots data from the well are also very important. Sonic logs are the principle source of well velocity data.
How are synthetic sonic logs used in geophysics?
In geophysics, we often model or “synthesize” measurements in order to enhance our interpretation of geophysical data. Synthetic seismograms often utilize sonic and density logs to produce impedance profiles in order to model seismograms in order for us to pick reflections on seismic data.
When did Robinson and Treitel create synthetic seismogram?
Synthetic seismogram studies have spanned many decades from the earlier days of 1-D modeling as described by Robinson and Treitel (1980) to the more recent descriptions of finite-difference anisotropic viscoelastic modeling as described by Carcione (2007).