Feasibility study for seismic monitoring of hydrocarbons using dipole sonic logs

Abstract

This study will determine the feasibility of using the changing elastic parameters of reservoir rocks to infer changes in fluids saturation, pressures, and temperatures during the production phase. These changes may be detected via seismic records at several production time windows. Previous works in this area involved measuring a well core's elastics properties in the lab, which limits the method to where core data is available. In this study, full-waveform acoustic logs have been used to compute the elastic properties of reservoir rocks. The use of this kind of log produces a more abundant set of elastic parameters over a broader depth interval, which better represents the real conditions of the reservoir. These data, along with the fluid flow simulation model, were used to construct maps for the elastic properties in saturated media, via Gassmann (1951) relationships and Biot (1956) theory. The methodology has been applied to the Santa Barbara field located in eastern Venezuela. The Santa Barbara field is a gas and oil productive field. The results have been compared favorably to those obtained in previous work using only well core data.