The Effective Stress Coefficient for Wave Velocities in Saturated Grain Packs

P093 THE EFFECTIVE STRESS COEFFICIENT FOR WAVE VELOCITIES IN SATURATED GRAIN PACKS ANNE-KARI FURRE Abstract 1 In time-lapse studies the stress dependence is an important factor to consider. If the pore pressure in a reservoir changes during production because of depletion or injection we need a good estimate of the effective stress response of the wave velocities. A common approach is to perform ultrasonic velocity measurements on dry laboratory cores (assuming the dispersion is negligible) at effective reservoir stress and combine the stress response of the rock with the velocity response of the fluid. In order to determine the true