Estimating the permeability from fluid-injection induced seismic emission

Abstract

During hydraulic-fracturing experiments or other experiments with borehole-fluid injections a micro-seismic activity can be observed. This was the case in the German Continental-Deep-Drilling Borehole at a depth interval of 9030 9100m(Engeser, 1996). About 200m of KBr/KCl brine were injected approximately 40 hours. The fluid injection induced almost 400 micro earthquakes in a spatial domain extending to 500 700m from the borehole in a lateral direction in the depth range 7:5 9km (Zoback and Harjes, 1997).