ABSTRACT

The time invariance of wave equations, an essential precondition for time-reversal (TR) imaging, is no longer valid when introducing attenuation. I evaluated a viscoelastic (VE) TR imaging algorithm based on a novel VE wave equation. By reversing the sign of the P- and S-wave loss operators, the VE wave equation became time invariant for the TR operation. Attenuation effects were thus compensated for during TR wave propagation. I developed the formulations of VE forward modeling and TR imaging. I tested my imaging approach in three numerical experiments. The first experiment used a 2D homogeneous model with full-aperture receivers to examine the time invariance of the VE TR imaging equation. Using the same model, the second experiment was used to demonstrate the method’s ability to characterize a point source. In the third experiment, I applied this method to characterize a complex source using borehole geophones. Numerical results illustrated that the VE TR imaging improved our knowledge of the source location, radiation pattern, and amplitude.

You do not currently have access to this article.