Amplitude and Bandwidth Recovery Beneath Gas Zones Using Kirchhoff Prestack Depth Q-Migration

Summary When imaging geologic structures below a viscoaoustic overburden, it is important to account for amplitude dimming, frequency loss, and phase distortion. Several viscoaoustic wave-equation based methods have been developed to solve this problem. We present a Kirchhoff approach. The technical significance of this approach is that we have found an efficient way to compute frequency-dependent traveltimes, which are crucial in the Kirchhoff integral. The validity of our technology is illustrated by data examples.