ALBERT

Description: A mechanism for seismicity induced by fluid injection operations is pore pressure increase via a diffusional process (left). This leads to a reduction in the effective normal stress on preexisting faults; allowing frictional resistance to fault sliding to be overcome. This mechanism requires a high permeable pathway from the fluid injection point to the preexisting fault. Even in the circumstances when injection fluids may be hydraulically isolated from any preexisting faults, the fault may be activated through perturbations in the stress field brought about by changes in volume or mass loading transmitted to the fault poroelastically (right: hydraulic fracturing example). Shale gas could help address the insatiable global demand for energy. However, in addition to risks of environmental pollution, the risk of induced seismicity during the hydraulic fracturing process is often considered as the major showstopper in the public acceptability of shale gas as an alternative source of fossil fuel. Other types of subsurface energy development have also demonstrated similar induced seismicity risks. This article presents an interdisciplinary review of notable cases of suspected induced seismicity relating to subsurface energy operations, covering operations for hydraulic fracturing, wastewater injection, conventional gas extraction, enhanced geothermal systems and water impoundment. Possible causal mechanisms of induced seismicity are described and illustrated, then methods to mitigate induced seismicity, encompassing regulations, including so‐called traffic light systems, monitoring and assessment, and numerical modeling approaches for predicting the occurrence of induced seismicity are outlined. Issues relating to public perception of energy technologies in regards to induced seismicity potential are also discussed. This article is categorized under: Photovoltaics 〉 Climate and Environment Fossil Fuels 〉 Climate and Environment Energy Infrastructure 〉 Economics and Policy Energy and Development 〉 Systems and Infrastructure