It has recently been shown that rather small perturbations in effective stress due to fluid injection or withdrawal may trigger microseismic events. Such events, typically in the magnitude range below magnitude 4 M-L, have similar characteristics to normal tectonic earthquakes, with double-couple focal mechanisms implying a dominant shear motion at the source. In this paper we examine the nature of this mechanical fluid-rock interaction for the case of fluid injection in a hydrocarbon reservoir. Our model is based on the combination of a model of seismicity in dry rocks and a model of pore fluid pressure diffusion. The former involves a finite difference approximation of the equation of motion, and the latter follows;a lattice Boltzmann [...]
