Please use this identifier to cite or link to this item:
Title: Fluid pressure drops during stimulation of segmented faults in deep geothermal reservoirs
Author: Piris, G.
Griera, Albert
Gómez Rivas, Enrique
Herms, I.
McClure, M.W.
Norbeck, J.H.
Keywords: Energia geotèrmica
Falles (Geologia)
Geothermal resources
Faults (Geology)
Issue Date: 16-Nov-2018
Publisher: Springer Open
Abstract: Hydraulic stimulation treatments required to produce deep geothermal reservoirs present the risk of generating induced seismicity. Understanding the processes that operate during the stimulation phase is critical for minimising and preventing the uncertainties associated with the exploitation of these reservoirs. It is especially important to understand how the phenomenon of induced seismicity is related to the pressurisation of networks of discrete fractures. In this study, we use the numerical simulator CFRAC to analyse pressure drops commonly observed during stimulation of deep geothermal wells. We develop a conceptual model of a fractured geothermal reservoir to analyse the conditions required to produce pressure drops and their consequences on the evolution of seismicity, fluid pressure, and fracture permeability throughout the system. For this, we combine two fracture sets, one able to be stimulated by shear-mode fracturing and another one able to be stimulated by opening-mode fracturing. With this combination, the pressure drop can be triggered by a seismic event in the shear-stimulated fracture that is hydraulically connected with an opening-mode fracture. Our results indicate that pressure drops are not produced by the new volume created by shear dilatancy, but by the opening of the conjugated tensile fractures. Finally, our results reveal that natural fracture/splay fracture interaction can potentially explain the observed pressure drops at the Rittershoffen geothermal site.
Note: Reproducció del document publicat a:
It is part of: Geothermal Energy, 2018, vol. 6, num. 24
Related resource:
ISSN: 2195-9706
Appears in Collections:Articles publicats en revistes (Mineralogia, Petrologia i Geologia Aplicada)

Files in This Item:
File Description SizeFormat 
687149.pdf4.08 MBAdobe PDFView/Open

This item is licensed under a Creative Commons License Creative Commons