Frequency-dependent AVO analysis

Abstract

A method for generalizing the conventional amplitude variation with offset model from an isolated interface to a scattering reservoir interval is presented. The advantage of this new method is that it can provide enhanced detection of subtle reservoir and pore fluid properties. First- and second-order expressions for the reflected compressional wave energy from a specified heterogenous interval are given. These expressions are applied to two problems of interest for reservoir description. One application is discriminating low versus higher saturations of hydrocarbons, and the other is detecting the extent of vertical stratification within a reservoir. The first-order expression is used for determining hydrocarbon saturations, and the second-order expression is used for detecting the magnitude of fine-scale layering within a reservoir. Synthetic models and field data examples are used in demonstrating the applicability of the proposed method.

Examination of the Seismic Characteristics of Onshore Reservoirs for Dom Gas Production Potentials in the Niger Delta Region of Nigeria

“…INICHINBIA, S; HAMZA, H intercept and gradient as shown in Figure 7 and this showed that the time domain amplitude shows a good sensitivity to changes in saturation. This model is derived from properties given by a well log containing a relatively thick, porous sandstone layer and the saturations are based on Gassmann fluid substitution (Foster et al, 2020). From careful analysis, both reservoirs produce typical Class II AVO response.…”