Microseismicity of Non-linear Fluid-rockInteractions - From Geothermic Stimulations toFracturing of Barnett Shales

摘要

Borehole stimulations by fluid injections are common for developments of hydrocarbon and geothermicreservoirs. Often they induce numerous microearthquakes. Spatio-temporal dynamics of such inducedmicroseismic clouds can be used to characterise reservoirs. However, a fluid-induced seismicity can becaused by a wide range of processes. We propose an approach to describing a broad range of non-linearfluid-rock interactions. We show that a linear pore pressure relaxation and a hydraulic fracturing are twoasymptotic end members of a set of non-linear diffusional phenomena responsible forseismicity triggering. Microseismicity of Barnett Shales shows signatures of a non-lineardiffusional triggering with an extremely strong hydraulic permeability enhancement in a 3-D domain ofthe reservoir. This indicates a process of a volumetric hydraulic fracturing via reopening of compliantpreexisting fractures.