Creating a high resolution velocity model using seismic tomography and impedance inversion

A computer system, comprising:

• one or more processors;
• memory;
• and
• one or more programs, wherein the one or more programs are stored in the memory and configured to be executed by the one or more processors, the one or more programs including instructions that when executed by the one or more processors cause the device to:
• generate a long-wavelength anisotropic velocity model by performing a tomographic inversion of one or more seismic data gathers using moveout data derived from the one or more seismic data gathers;
• access an attenuation model that includes frequency-dependent attenuation factors for each of a plurality of locations in the geological medium;
• combine the long-wavelength anisotropic velocity model with the attenuation model to produce a long-wavelength velocity and attenuation model;
• perform prestack depth migration on the one or more seismic data gathers from a time domain to a depth domain using the long-wavelength velocity and attenuation model to produce one or more seismic image gathers;
• apply a dip-consistent filter to the one or more seismic image gathers to produce one or more filtered seismic image gathers;
• transform the one or more filtered seismic image gathers from the depth domain to the time domain;
• and
• generate a full-band impedance model for the geological medium by performing impedance inversion of the one or more filtered seismic image gathers in the time domain using the long-wavelength velocity and attenuation model;
• applying a spatial-coordinate-independent calibration to the full-band impedance model using one or more frequency-spectral calibration factors determined from at least one of well-log derived velocities, well-log derived impedances, and high-contrast horizons to produce a frequency calibrated full-band impedance model;
• and
• detecting fluid pressure anomalies in the geological medium using the frequency calibrated full-band impedance model.

A non-transitory computer readable storage medium storing one or more programs, the one or more programs comprising instructions, which when executed by an electronic device with one or more processors and memory, cause the device to:

• generate a long-wavelength anisotropic velocity model by performing a tomographic inversion of one or more seismic data gathers using moveout data derived from the one or more seismic data gathers;
• access an attenuation model that includes frequency-dependent attenuation factors for each of a plurality of locations in the geological medium;
• combine the long-wavelength velocity model with the attenuation model to produce a long-wavelength velocity and attenuation model;
• perform prestack depth migration on the one or more seismic data gathers from a time domain to a depth domain using the long-wavelength velocity and attenuation model to produce one or more seismic image gathers;
• apply a dip-consistent filter to the one or more seismic image gathers to produce one or more filtered seismic image gathers;
• transform the one or more filtered seismic image gathers from the depth domain to the time domain;
• generate a full-band impedance model for the geological medium by performing impedance inversion of the one or more filtered seismic image gathers in the time domain using the long-wavelength velocity and attenuation model;
• apply a spatial-coordinate-independent calibration to the full-band impedance model using one or more frequency-spectral calibration factors determined from at least one of well-log derived velocities, well-log derived impedances, and high-contrast horizons to produce a frequency calibrated full-band impedance model;
• and
• detect fluid pressure anomalies in the geological medium using the frequency calibrated full-band impedance model.