Man-made earthquake risk reduced if fracking is 895m from faults

The risk of man-made earthquakes due to fracking is greatly reduced if high-pressure fluid injection used to crack underground rocks is 895m away from faults in the Earth's crust, according to new research. The recommendation, from the ReFINE (Researching Fracking) consortium, is based on published microseismic data from 109 fracking operations carried out predominantly in the USA. Jointly led by Durham and Newcastle Universities, UK, the research looked at reducing the risk of reactivating geological faults by fluid injection in boreholes. Microseismic data Researchers used microseismic data to estimate how far fracking-induced fractures in rock extended horizontally from borehole injection points. The results indicated there was a one per cent chance that fractures from fracking activity could extend horizontally beyond 895m in shale rocks. There was also a 32 per cent chance of fractures extending horizontally beyond 433m, which had been previously suggested as a horizontal separation distance between fluid injection points and faults in an earlier study. The research is published in the journal Geomechanics and Geophysics for Geo-Energy and Geo-Resources .