An experimental study of influence of water saturation on velocity and attenuation in sandstone under stratum conditions

To study the influence of the gas saturata to seismic wave propagation, at the temperature and pressure of stratum, the velocity and attenuation Q of primary and share waves in Changqing sandstone samples are measured under different saturation degrees by ultrasonic. The result shows that under the high frequency condition, fluid contents in sandstone samples have nearly no effect on share wave velocity, but affects obviously primary wave velocity; and the relation between fluid content and wave attenuation is different for S-wave and P-wave. The analysis to the experiment result and the corresponding influence mechanism is made, and an application example is presented.