Simultaneous migration of primary and free surface multiples: modeling data analysis

Under the condition of reverse time migration and cross correlation imaging, simultaneous migration images of primary and free surface multiples can provide wider underground illumination to make up for the insufficient coverage of the reflections, Therefore, it is not necessary to predict and separate multiples. However, migration artifacts may also be introduced during the process of joint imaging. In this paper, we firstly analyzed the simultaneous migration imaging conditions. Imaging with multiples information needs to use the source wavelet and reverse phase of seismic records as the source side wave field in the reverse-time migration and forward propagate, and the original seismic record as detection side wave field and back propagate, will obtain relative fidelity amplitude imaging results. The results of numerical experiments show that, although the simultaneous reverse time migration imaging of primary and free surface multiples based on cross-correlation imaging condition can provide wider underground illumination, the migration artifacts is also enhanced with the increase in the energy of free surface multiples. When the energy of multiples becomes weak, the intensity of wide-angle illumination by free surface multiples is also weakened, and therefore the simultaneous migration imaging of primary and free surface multiples needs to be further studied.