Slow P‐Wave Attenuation Yielding From Berea Sandstone With Double Porosity

Double porosity model differentiates fluid pressure between contact of grains (COG) and the main pore space. This study is motivated by determining phase velocity ( V p s ) and the quality factor ( Q p s ) of slow P‐wave for double porosity rock. The trick is the use of the compressibility matrices calibrated from (ultrasonic) fast P‐wave data. Berea sandstone saturated with water is used for illustration. Double porosity models (with the real Darcy permeability k D and assumed‐zero k D ) are both capable of well regenerating the phase velocity ( V p ) and quality factor ( Q p ) of fast P‐wave ultrasonically measured on the sandstone. However, the two double porosity models yield considerably different Q p at frequencies exceeding 10 7 Hz. In addition, Biot theory is used as a single porosity model for the calculation of V p s and Q p s . It is found that the double porosity model with the real k D is substantially different from the single porosity model in the resulting V p s at high frequencies. The results show that the behavior of slow P‐wave at frequencies higher than 10 5 Hz is governed by the double porosity model rather than the single porosity model.