Abstract: A method of the invention provides improvement in the quality of coupled simulations between geomechanical and reservoir models by constructing a geomechanical model of an underground zone intended to be coupled with a reservoir model allowing simulation of fluid flows in the zone, from a geological model of the zone discretized by a fine grid. Geomechanical properties are associated with the various cells of the geological model on the basis of experimental data, the underground zone is discretized by a geomechanical grid with larger cells than the geological grid, and a scale change is applied to the geomechanical data included in the geological model in order to define equivalent geomechanical properties at the scale of the geomechanical grid of the zone.

Abstract: Method of constructing a geomechanical model of an underground zone intended to be coupled with a reservoir model allowing simulation of fluid flows in the zone, from a geological model of the zone discretized by a fine grid. Basically, geomechanical properties are associated with the various cells of the geological model on the basis of experimental data, the underground zone is discretized by a geomechanical grid with larger cells than the geological grid, and a scale change is applied to the geomechanical data included in the geological model in order to define equivalent geomechanical properties at the scale of the geomechanical grid of the zone. Application: improvement in the quality of coupled simulations between geomechanical and reservoir models.