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Influence of the Creep Effect on the Low-Frequency Measurements of the Elastic Moduli of Sedimentary Rocks
- Publisher: European Association of Geoscientists & Engineers
- Source: Conference Proceedings, 81st EAGE Conference and Exhibition 2019, Jun 2019, Volume 2019, p.1 - 6
Abstract
In this study, we investigate the influence of the creep phenomenon on the drifts of the dynamic moduli of three sedimentary rocks represented by Savonnieres limestone, Berea sandstone and Eagle Ford shale. We report the results of the low-frequency measurements of elastic moduli using the forced-oscillation method, which were carried out for 120 hours on three room-dry samples at frequencies of 0.1 Hz to 120 Hz under a uniaxial pressure of 10 MPa. We found that all moduli reduce with time, with the largest changes occurring in Eagle Ford shale, where the bulk and shear moduli decrease by 12% and 8%, respectively. We also found that the drifts of the bulk and shear moduli measured 24–30 hours after commencing the experiments do not exceed 2% for all samples.