THE EFFECT OF ATTENUATION ON FREQUENCY-DEPENDENT AVO BASED ON POROUS MEDIA THEORY

An oil and gas reservoir is a typical porous medium. The frequency-dependent amplitude variation with offset (FDAVO) is a recently developed technology for reservoir prediction. Traditional FDAVO is normally based on the Zoeppritz equation and does not involve the parameter of wave attenuation. The effect of attenuation on FDAVO was discussed based on the porous media theory. The wave reflections on the top interface of the reservoir and on the interface between oil-saturated and water-saturated reservoirs are simulated and analyzed. The results indicate that: the effects of attenuation on the reflection of slow compression waves are obvious for both interfaces; the effects of attenuation on the reflection of fast compression waves are slight for the top interface of the reservoir and more obvious for the interface between the oil-saturated and water-saturated reservoirs, especially in the lower frequency range; the effects of attenuation on the reflection of conversed shear wave are slight for the top interface of the reservoir and complicated for the interface between the oil-saturated and water-saturated reservoirs, especially in the frequency range of 0-50.