Space-Adaptive Inversion

Space-adaptive wavelet processing and inversion to relative seismic impedance

Space-adaptive inversion involves a spatially varying wavelet processing phase to stabilize the seismic wavelet followed by discrete spike inversion to generate relative impedance within the bandwidth of the conditioned seismic wavelet. The full space-adaptive inversion workflows consist of the following key steps:

1. Signal-to-noise ratio estimates
2. Wavelet estimation
3. Space-adaptive wavelet equalization
4. Iterative discrete spike inversion

 Input to space-adaptive inversion may be the final poststack amplitude cubes or prestack AVO attributes, such as compressional velocity, shear velocity, and density. The process allows for a spatially varying phase component in the data, but is dependent upon a stable, spatially invariant nonminimum phase; hence, data must be carefully acquired and processed before inversion to ensure stable and reliable phase and amplitude. Seismic data conditioning is a key step to preparing the data for inversion. Time variance in the seismic wavelet is overcome by focusing on time windows spanning the reservoir zone of interest.