Sensitivity Measurements of P-Wave and S-Wave Velocities During Fluid Substitution
Blessing T. Biyela
Geological Sciences, UH/UCT, Rondebosch, South Africa
Fluid substitution methods estimates seismic velocities and densities that results from changes in pore-fluids. Most of petroleum industries use Gassmann’s equations to perform fluid substitution. In this study I also used Gassmann’s equations to perform fluid substitution. Here I present the changes in Vp and Vs when the sandstone is filled with brine, gas or oil. I observed how the velocities and density change with respect to temperature, pore-pressure, salinity, API, gas-oil ratio and specific gravity of a gas. I also show how Vp-Vs relationships of brine, gas and oil deviate from mud rock line. This study is important because it provides an interpreter with a valuable tool for modeling various fluid scenarios that might explain an observed amplitude variation with offset (AVO).
AAPG International Conference and Exhibition, Cape Town, South Africa 2008 © AAPG Search and Discovery