Abstract
We have designed and built a versatile testing device to perform hydraulic fracturing experiments under true triaxial conditions. The device, based on a stiff biaxial frame that can be installed in a servocontrolled press, can accommodate cube rock samples of up to 150 mm-edge. Using a low-permeability rock known as Blanco Mera granite, we have performed a series of tests across a range of confining pressures including hydrostatic, normal, and strike-slip regimes. We have verified the applicability of two simple fracture mechanics-based models for the interpretation of experimental results, and we have determined the value of tensile strength of the rock from the injection curves recorded. The orientation of the hydraulically-triggered fractures with respect to the applied stress has also been analyzed. Although the models proposed by Rummel and Abou-Sayed provided reasonably satisfactory results, especially for hydrostatic and strike-slip tests, the presence of heterogeneities and defects in the rock matrix may have a strong influence on the fracture behavior and, therefore, affect the interpretation of hydrofracturing tests.
Original language | English (US) |
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Journal | Geomechanics and Geophysics for Geo-Energy and Geo-Resources |
Volume | 9 |
Issue number | 1 |
DOIs | |
State | Published - Mar 16 2023 |
Bibliographical note
KAUST Repository Item: Exported on 2023-04-03Acknowledgements: Open Access funding provided thanks to the CRUE-CSIC agreement with Springer Nature. This work was funded by REPSOL S.A. and the support of the Spanish Ministry of Science and Innovation (PID2021-126419NB-I00). A. Muñoz-Ibáñez also acknowledges the Margarita Salas grant from the Spanish Ministry of Universities, funded by the European Union – Next Generation EU.