Poroelastic analysis of permeability effects in thinlylayered porous media

摘要

The mechanism of wave-induced fluid flow, which causessignificant attenuation and dispersion of seismic waves inheterogeneous porous media, opens a potential opportunityto estimate fluid-mobility properties from seismic data. However,the permeability effects on seismic data vary for differentreservoir environments, so rules of thumb are difficult toestablish. Two types of reservoir models were selected. Onerepresents shallow, unconsolidated, low-impedance reservoirs.The other represents deep, consolidated, high-impedancereservoirs. Using analytic equations and wave-propagationnumerical studies, permeability effects were investigatedon the magnitude and phase of normal-incident reflectioncoefficients from an interface between an upper nondispersivemedium and a lower thinly layered porous medium. Thestudy found that permeability can affect reflection amplitudessignificantly. For high-impedance reservoirs, magnitudeof the reflection coefficient decreases when permeabilityincreases. However, for low-impedance reservoirs, reflectionmagnitude increases as permeability increases.