Valley, Benoît

Voici les éléments 1 - 10 sur 52

Métadonnées seulement
Stress inversion using borehole images and geometry evolution of the fractures in the Rittershoffen EGS project (Alsace, France)
(2017-10-26)
Azzola, Jérôme
;
Valley, Benoît
;
Schmittbuhl, Jean
;
Genter, Albert
;
Hehn, Régis
Métadonnées seulement
Stress Measurements in Crystalline Rock: Comparison of Overcoring, Hydraulic Fracturing and Induced Seismicity Results
(2017-8-28)
Krietsch, Hannes
;
Gischig, Valentin
;
Jalali, Mohammadreza
;
Amann, Florian
;
Evans, Keith F.
;
Doetsch, J.
;
Valley, Benoît
Métadonnées seulement
Stress Characterisation and stress modeling at the Grimsel Test Site for the In-situ Stimulation and Circulation Project
(2016-11-19)
Dutler, Nathan
;
Valley, Benoît
;
Krietsch, Hannes
;
Amann, Florian
;
Gischig, Valentin
;
Evans, Keith F.
Métadonnées seulement
Architecture of a fault zone in Opalinus Clay at the Mont Terri laboratory (Switzerland)
(2016-11-19)
Kakurina, Maria
;
Guglielmi, Yves
;
Nussbaum, Christophe
;
Valley, Benoît
Métadonnées seulement
Optimisation of borehole trajectory in order to minimize borehole failure
(2016-11-19)
Dahrabou, Asmae
;
Valley, Benoît
;
Ladner, Florentin
;
Guinot, Frédéric
;
Meier, Peter
Métadonnées seulement
Preliminary stress characterization for an in-situ stimulation experiment at the Grimsel Underground Laboratory
(2016-4-1)
Krietsch, Hannes
;
Doetsch, J.
;
Gischig, Valentin
;
Amann, Florian
;
Jalali, Mohammadreza
;
Madonna, Claudio
;
Evans, Keith F.
;
Valley, Benoît
;
Giardini, Domenico
;
Wiemer, Stefan
;
Maurer, Hansruedi
;
Loew, Simon
A decameter-scale in-situ stimulation experiment is currently being executed at the Grimsel Test Site in Switzerland, spanning from hydraulic fracturing to controlled fault-slip experiments. For the feasibility of this project the in-situ stress tensor is of foremost importance. Therefore a unique stress characterization campaign combining stress relief methods (overcoring of USBM and CSIRO-HI probes) with hydraulic fracturing (HF) and hydraulic testing on pre-existing fractures (HTPF) in three boreholes was conducted in a first phase of this project. During all hydraulic stress measurements, micro-seismicity was monitored and localized in real time utilizing a dense network of piezo-electric sensors. In this contribution, we present preliminary results of the stress characterization and compare the derived stress tensor with previous estimates of the stress state. The stress characterization campaign was conducted in three boreholes, one sub-vertical and two sub-horizontal boreholes, assuming that the sub-vertical and one sub-horizontal are parallel to a principal stress component. A major task in this contribution is the integration of the different stress characterization methods. Our results of the different methods (overcoring and HF) are largely consistent, but disagree with some of the previous stress orientation estimates. From the new campaign the overcoring measurements indicate a sub-horizontal sigma1 of 17.3 MPa with a strike of 145°, a sigma2 of 9.7 MPa with 241°/69° and a sigma3 of 8.3 MPa with 055°/21° using an isotropic approach for inversion calculation. Whereas the USBM-Probe measures a projection of the principal stresses in a plane normal to borehole axis, the CSIRO-HI Probe provides the real 3D stress tensor. The HF and HTPF measurements indicate a far-field minimum horizontal stress between 8.7 and 9.1 MPa, consistent with the overcoring. Principal stresses, estimated by location of micro-seismic events during HF and HTPF, suggest that the maximum horizontal stress strikes EW, the minimum horizontal stress strikes NS and sigma2 stress direction is sub-vertical dipping towards south. One sub-horizontal borehole dedicated to stress characterization penetrates one of the fault zones targeted for a future fault-slip experiment. Results reveal a significant drop in the minimum stress component towards the fault zone. This stress information will be critical for the planning of the stimulation phase of the project.
Métadonnées seulement
Development of connected permeability in massive crystalline rocks through hydraulic fracture propagation and shearing accompanying fluid injection
(Wiley Online Library: John Wiley & Sons, Ltd, 2016)
Preisig, Giona
;
Eberhardt, Erik
;
Gischig, Valentin
;
Roche, Vincent
;
van de Baan, Mirko
;
Valley, Benoît
;
Kaiser, Peter K.
;
Duff, Damien
;
Lowther, R.
;
Gleeson, T.
;
Ingebritse, E.
Métadonnées seulement
Reservoir Stimulation Experiments at the Grimsel Test Site: Stress Measurements using Hydraulic fracturing, Hydraulic Tests on Pre-existing Fractures and Overcoring
(2015-12-1)
Doetsch, J.
;
Gischig, Valentin
;
Amann, Florian
;
Madonna, Claudio
;
Jalali, Mohammadreza
;
Valley, Benoît
;
Evans, Keith F.
Métadonnées seulement
In-situ clay faults slip hydro-mechanical characterization (FS experiment), Mont Terri underground rock laboratory
(2015-11-26)
Valley, Benoît
;
Nussbaum, Christophe
;
Valley, Benoît
;
Guglielmi, Yves
Métadonnées seulement
Stress magnitudes estimate from borehole failure at the Basel EGS reservoir
(2015-11-26)
Valley, Benoît
;
Evans, Keith F.

Valley, Benoît

Résultat de la recherche

Filtres

Auteur

Éditeur

Institution

Sujet

Fichier(s) présent(s)

Type

Paramètres

Trier par

Résultats par page

Options

Valley, Benoît

Résultat de la recherche

Filtres

Auteur

Éditeur

Institution

Sujet

Fichier(s) présent(s)

Type

Paramètres

Trier par

Résultats par page