Enhanced Geothermal Systems

Project 1: Injection-induced seismicity: reducing risk using high stress path reservoirs and temperature-induced stress preconditioning

Investigators: Barnaby Fryer, Gunter Siddiqi (Swiss Federal Office of Energy), and Lyesse Laloui

Description: The goal of this numerical investigation is to develop a stimulation technique that has a low likelihood of inducing a large magnitude seismic event. The methodology proposed attempts to make use of temperature-induced stress changes to precondition the stress field yielding a more favorable stress state prior to stimulation.

Project 2: Critically-stressed reservoir stimulation direction via stress preconditioning in horizontal EGS doublets

Investigators: Barnaby Fryer, Xiaodong Ma (ETH Zürich), Gunter Siddiqi (Swiss Federal Office of Energy), and Lyesse Laloui

Description: The goal of this investigation is to numerically investigate if it is possible to direct a shear stimulation treatment towards a pre-existing well by preconditioning the stress field before stimulation. This investigation is specifically concerned with critically-stressed reservoirs, in keeping with the common in-situ stress states in many EGS reservoirs. All stress regimes are investigated.

Project 3: An EGS reservoir stimulation technique that lends itself to safe shut-in in the event of a large seismic event

Investigators: Barnaby Fryer, Gunter Siddiqi (Swiss Federal Office of Energy), Lyesse Laloui

Description: Here a numerical investigation is performed with the goal of demonstrating a stimulation technique that can be more readily shut-in in the event that project needs to be stopped. The methodology takes advantage of the way that reservoirs can be stimulated using temperature changes and how temperature changes propagate through rock.