Reservoir induced seismicity

This research uses observations of reservoir induced seismicity (RIS) at A u reservoir. NE Brazil, to investigate the spatial and temporal evolution of effective stress in the region and its relationship to fault permeability. A u reservoir was constructed in 1983 and has a capacity of 2.4 x lO m maintained by a 34 m high earth-filled dam constructed on Precambrian shield. Annual reservoir variation is 3-6 m which results in annual seismic activity due to a proposed mechanism of pore pressure diffusion (Ferreira et al. (1995), do Nascimento et al. (2003a)). Digital data at A u... 

Fehler, M., Jupe, A. and Asanuma, H. (2001). More Than Cloud New techniques for characterizing reservoir structure using induced seismicity. The Leading Edge, 324-328. 

Disposal of liquid hazardous waste has been undertaken by injection into deep weiis iocated in rock below freshwater aquifers, thereby ensuring that poiiution of groundwater suppiies does not occur. In such instances, the waste is generally injected into a permeable bed of rock several hundreds or even thousands of metres below the surface, which is confined by relatively impervious formations. However, even where geological conditions are favourable for deep well disposal, the space for waste disposal frequently is restricted and the potential injection zones are usually occupied by connate water. Accordingly, any potential formation into which waste can be injected must possess sufficient porosity, permeability, volume and confinement to guarantee safe injection. Also, the piezometric pressure in the injection zone influences the rate at which the reservoir can accept liquid waste. A further point to consider is that induced seismic activity has been associated with the disposal of fluids in deep wells (see the following text). 

The types of GDIE in China are plentiful and various and among them, the main types are slope instability, surface rupture, sand Liquefaction, debris flow and ground deformation, and secondary are collapses by seismic and barrier lake induced by earthquake with overflow, and seismic surge wave, tsunami and reservoir induced earthquake are rare types in China. 

This project is of interest for several reasons, but primarily because the deep fluid is used as a closed loop, avoiding surface storage of brines, and because the seismicity induced by stimulation of the reservoir is continually watched in order to limit the risks. The Soultz-sous-Forets geothermal site could be a... 

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