Nonlinear Viscoelastic Behavior of Sedimentary Rocks: II. Hysteresis Effects and Influenece of Fluid Type on Elastic Moduli

TitleNonlinear Viscoelastic Behavior of Sedimentary Rocks: II. Hysteresis Effects and Influenece of Fluid Type on Elastic Moduli
Publication TypeJournal Article
Year of Publication1998
AuthorsTutuncu, A. N., A. L. Podio, and M. M. Sharma
JournalGeophysics
Volume63
Issue01
Start Page195
Pagination195-203
Date Published01/1998
Abstract

Uniaxial stress cycling experiments were conducted on dry, brine saturated and hexadecane saturated Berea sandstone samples to observe in detail the hysteresis in stress-strain diagrams and to understand the influence of different fluids on the strain amplitude dependence of elastic moduli and attenuation. Cycling experiments were also conducted with sandstone samples saturated with CTAB, a cationic surfactant that renders the mineral surfaces hydrophobic. Hexadecane and CTAB were selected so as to investigate the relative contributions of adhesion hysteresis and stick-slip sliding on attenuation in sedimentary granular rocks. Young’s moduli and Poisson’s ratios obtained from the cycling tests show a significant dependence on strain amplitude on dry as well as water and hexadecane saturated samples. Bow-tie-shaped diagrams are obtained when loading and unloading tangent moduli are plotted against strain. The type of fluid in the pore space and at the grain contacts has a large influence on the hysteresis observed in the stress-strain diagrams.

DOI10.1190/1.1444313