Q Tomography / Q Migration

Extension of 3D migration based tomography

TGS has developed a frequency domain tomographic inversion to estimate frequency dependent energy attenuation by using prestack depth migration common image gathers (CIGs).

Q tomography is an extension of 3D migration-based tomography.

The input is based on Common Image Pont (CIP) gathers. Higher frequencies suffer more loss than lower frequencies in migration therefore to minimize this effect the frequency spectrum is used as well as the amplitude to provide relative scaling. The correction of migration stretching is a key to improved results. TGS can run Q-migrations using Kirchhoff, Beam, and RTM algorithms.

TGS has developed a frequency domain tomographic inversion to estimate frequency dependent energy attenuation by using prestack depth migration common image gathers (CIGs). The frequency dependent attenuation is estimated from the centroid frequency difference for reflections in CIGs. Migration stretch and ghost effects are taken into account to get correct measurements of frequency. This method makes corrections for these factors to obtain correct frequency difference, utilizes the actual ray path and avoids using amplitude information. It is relatively insensitive to some amplitude loss factors, such as geometric spreading, reflection and transmission loss, source and receiver radiation patters.