​ADF(R) Images KH by Imaging Seismic Dispersion in the Frequency Domain

KH from Seismic

​

Circa 1975, the industry made a simplification by assuming that all seismic frequencies have the same velocity.  Frequency dependent velocity (“dispersion”), was believed to occur, but only at high frequencies.  Apex realized that permeability coupled with reservoir thickness cause large velocity variations with frequency predominantly at lower frequencies.

Frequency dependent velocity means frequency dependent reflection coefficients, which in the presence of layers with KH cause spectral compression in the frequency domain. However, seismic data is replete with tuning effects, which also cause frequency domain compression.  What makes ADF(R) unique is the ability to remove tuning effects before measuring frequency domain compression, the result of which is reliable KH measurements.

​