Induced Fluid Earthquakes (FIEs) in geo-reservoirs have been causing significant human, economic, and infrastructure damage for decades. FIEs result from the interaction between injected fluid pressure perturbations, in-situ stresses, frictional and rupture processes at micro to macro scales, and the geometric complexity of the fault zone. The maximum magnitude of FIEs is generally thought to be controlled by the injected volume of fluid and the shear modulus of the zone of interest. However, recent observations have shown FIEs with magnitudes up to a thousand times larger than this criterion, indicating an underestimation of FIE maximum magnitude. This underestimation could be related to high initial stress state on faults and a heterogeneous pore fluid distribution or heterogeneous stresses, allowing the rupture to propagate out of the pressurized zone.
