Publication Name: Australasian Exploration Geoscience Conference 2019
Authors: Wenhui Tan, Vassily Mikhaltsevitch*, Maxim Lebedev, Stanislav Glubokovskikh, Boris Gurevich
Date Published: September 2019
Number of Pages: 3
Abstract:
In this study we examine the effect of the boundary conditions on the laboratory measurements of the elastic properties of a fluid-saturated sedimentary rock at low frequencies. In laboratory experiments associated with studying fluid effects on elastic properties of a porous rock sample, the tested sample cannot be completely sealed due to the presence of the fluid lines connected to its pore space. These lines form a pore-fluid storage which can affect the results of the elastic moduli measurements of fluid-saturated rocks. We developed a modified version of the Gassmann model which can estimate the bulk moduli of fully saturated rocks in dependence on the capacity of the pore-fluid storage. Here, we compare the predictions of the modified Gassmann model with the moduli measured on an ndecane-saturated limestone sample with the volume of the pore-fluid storage changing from 2 ml to 260 ml. The experimental results were obtained using a low-frequency apparatus based on the forced-oscillation method at a frequency of 0.1 Hz. We demonstrate that the predictions of the modified Gassmann model are in good agreement with the experimental data.