Wave equation forward modeling for volcanic rock

The deeply buried volcanics in Songliao basin leads to very low imaging accuracy for underlying formation, which has some negative effect on the structure interpretation. In order to research the effect degree of volcanics on underlying formation, the forward modeling based on wave equation was used to analyze the seismic response characteristics of different theoretical volcanics models according to nine kinds of wave impedance association and two kinds of lithological association. The propagation process of seismic wave can be shown illustratively on snapshots, which is beneficial to analyze the effect of volcanics on underlying formation imaging. The forward modeling shows that the unclear reflection of bottom boundary in volcanics is for the shielding effect caused by particular wave impedances between the volcanics and the underlying formation. The discontinuity reflectance signature of underlying continuous formation will become more obvious when the volcanics is thick, resulting in forming pseudo- faults and structures. The modeling results show that the forward modeling based on wave equation can be used to accurately simulate the propagation process of seismic wave in volcanic rock, discover the shielding effect of volcanic to the underlying formation, find out the pseudo- faults and structures caused by the difference of volcanics thickness and its wave impedances, and eliminate the impact on structure interpretation eventually.