To Induce or Not to Induce

In the last few years, major and damaging earthquakes were felt in regions supposedly affected by a low rate of natural seismicity. Such events have become an extremely important topic of discussion in both Europe and North America, since several major events were associated to industrial activities. The main focus of this proposed research is the study of induced seismicity during exploitation of natural underground resources. More specifically, this proposal focuses on one side on a detailed understanding of the deep fault and/or fractures reactivation associated with the fluid injection. On the other side, the proposed research plans to investigate the mitigation of large magnitude induced seismicity, which may pose at risk the affected population and structures, as well as acting as obstacle to the development of new techniques for the exploitation of deep underground resources. First the project aims to understand the physics associated with the induced seismicity caused by anthropogenic activities. Secondly, the project aims to investigate in which conditions fluid-induced seismicity can be used as a tool. For example, the shearing process of fault and fracture, or the creation of new fractures, are needed to increase the permeability, and hence to enhance the fluid circulation at depth, eventually resulting in a more efficient energy production. However, such processes may, at the same time, produce seismicity that can be felt by local population.

• How is the induced seismicity affecting the growth of a geothermal reservoir? When does it act as a potential seal breaching during storage operation?
• Is it possible to use induced seismicity to develop a high permeability system, while constraining the earthquakes maximum magnitude? Or can a gas be stored in a safe (no seismic) way?

Understanding the fundamental processes will help in finding new methods to safely extract energy, whose request nowadays is constantly increasing.

The project will address the above open questions by theoretical studies, laboratory, and applied fieldwork. I plan to use data collected from on-going experiments (laboratory and in-situ) to improve numerical models. Numerical tools to be used include: thermo-hydromechanical modeling (THM), discrete fracture network (DFN), and statistical, as well as hybrid simulators.