Reflection Coefficient Analysis Based on White Layered-patchy Saturation Model

Abstract

Although significant advancement has occurred in the interpretation of seismic amplitude-variation-with-offset AVO anomalies, a theory is lacking to guide the interpretation of frequency-dependent seismic anomalies.This paper takes into account the mesoscopic fluid flow in the reservoir.And the reservoir is thought to be patchy-saturated dispersive medium,while the overlying shale is considered to be nondispersive medium.I derive a new expression of the incident-dependent reflection coefficient as a function of frequency at an interface between a nondispersive medium and a patchy-saturated dispersive medium,and analyze the variation of reflection coefficient with the incident angle and frequency under the condition of different combination of overlying shale and the reservoir. It suggests that the reflection is dependent on the viscoelastic characteristic difference between overlying shale and the reservoir,frequency and fluid flow in pores. Under the condition of different combination of overlying shale and the reservoir, the variation of reflection coefficient magnitude is divided into three AVOF classes.Also,AVO curve type is different with variable frequency.