Scattering Attenuation and Transmission Loss Effect on Acoustic Impedance Inversion

Xingang Chi and Dehua Han
University of Houston, Houston, TX

The reflection response of a seismic target is affected by transmission loss and scattering wave caused by the thinly layered reflector overburden and they can significantly attenuate the seismic response of the target zone. When we do the acoustic impedance inversion, the value of inverted acoustic impedance can not be inverted correctly because the target seismic response is already affected by scattering attenuation and transmission loss. A model-based method is used to compensate for the attenuated target seismic response. It is assumed that there is no intrinsic attenuation by simplification and the thinly layered reflector overburden is 1-D fluctuation media. The seismic inversion method has been cast as an algorithm of band limited impedance inversion. It can be used to invert seismic data using a well log, or some known impedance function. Detailed impedance values are provided by the integrated seismic data, and the low frequency trend is provided by the well-log. The compensation will be done for the loss of target seismic response caused by scattering attenuation and transmission loss. The application of these combined procedures is demonstrated for P-waves in an elastic thinly-layered medium. These techniques offer a suitable tool to compensate for the thin-layer influence on amplitudes of seismic reflection data and inverted acoustic impedance. After the compensation, the reservoir impedance will be inverted correctly. This inverted property can be better used for the reservoir model.