Investigation of Acoustic Velocity of Carbonate Rocks and the Effect of Cracks on Velocity

Abstract

The acoustic velocity is very closely related to rock properties such as porosity, permeability etc. These relationships are particularly important for carbonate rocks. It is thus vital to examine the interpretation of acoustic velocity as a function of rock properties. The primary goal of this study was to examine how rock properties e.g., porosity, permeability and crack density, affect the acoustic velocity of rock samples. For this purpose, 24 carbonate plug samples from Ras Al-Khaimah were examined. The recrystallized carbonates depicted a very low porosity and a significant amount of fractures were examined. A unified theory for elastic wave propagation through porous media containing cracks was used for the quantitative description of cracks and the relationship between cracks and acoustic velocity was also investigated. A positive correlation was found between the P-wave velocity difference and the corresponding inverted crack density difference. The results of this study provide new insights into the acoustic behavior of carbonate rocks.