Geomechanical Properties from Nanoindentation Testing and Inclusion-Based Rock Physics Models

H. CELLERI; E. CAMILION; M. NOYA; A. FLORIDIA; G. PANIZZA; T. PIQUE; A. CANEIRO; M. SÁNCHEZ; J. RAMALLO; C. FUERTES

Golden, Colorado

Congreso; 54th U.S. Rock Mechanics/Geomechanics Symposium; 2020

Geomechanics properties are key to effectible analyze the stimulation and production process. These properties are hardly known during the exploration phase of a new formation. Cores are seldom acquired beforehand and drilling cutting may be the only available rock sample. In this work, we performed nanoindentation tests on three different rock types, a sandstone, a tight sandstone (Lajas Fm.) and a shale (Los Molles Fm.). Elasto-plastic properties (Hardness; Elastic moduli) and toughness distributions are obtained. Bentheimer sandstone has an almost biphasic quartz/pore distribution with quartz mineral grains big enough to test single grains. These results are compared to those in literature. Ion beam milling is found to be the best rock sample surface preparation procedure for nanoindentation testing, with a lower number of discarded tests due to rough surface. Nanoindentation homogenized elastic moduli are compared to results from static and dynamic tests in plug samples and from rock physics model using mineral properties from literature. Nanoindentation homogenized elastic moduli compares well with the homogenized mineral properties if the porosity, obtained from petrological studies, is incorporated in the rock physics model. Elastic moduli obtained from nanoindentation is comparably higher than those obtained from static tests. Homogenized Young´s moduli values differ less than 10% with the dynamic measurements at high pressures.