Correlation Between Mechanical Properties of Sandstones and P-Wave Velocity in Different Degrees of Saturation

Abstract

The aim of this study is to correlate the strength parameters of sandstones with P-wave velocity at different degrees of saturation. For this purpose, six different sandstone types were collected from several locations of upper red formation in southwestern Qom and a comprehensive laboratory testing program was conducted. Experimental results indicated that strength and deformability properties of the sandstones decreased with increasing degree of saturation, while Vp showed increasing trend with increasing degree of saturation. The trends are more consistent for low to medium strength sandstones than those of high strength which display less predictable behavior. The sandstones used in this study show a significant reduction of up to 61% and 58% in UCS and E, respectively, between the dry and saturated states. Simple regression analysis results indicate that prediction of the strength properties of rocks directly from Vp at different degrees of saturation is possible. A series of different prediction relationships were also developed by using independent variables such as Vp and degree of saturation.