A computer-implemented method for configuring a geological simulation grid having an already-designed geometrical grid, without re-designing the geometrical grid, the method comprising: - providing a geometrical grid that conforms to a set of geological structures of a geological environment, the geometrical grid having cells and connections each between a respective pair of cells of the geometrical grid, the grid being unstructured and comprising non-neighbor connections; - providing a geometrical surface that represents a geological surface of the geological environment, the geological surface being not included in the set of geological structures, the geometrical surface being provided based on data obtained after a determination of the geometrical grid; - identifying geometrical structures of the geometrical grid representing a local intersection with the geometrical surface, within the set of all connections between pairs of cells, thereby identifying connections each between a respective pair of cells, each identified connection corresponding to a respective location of the geometrical surface and representing the local intersection, wherein the identifying includes determining pairs of cells each including a respective first cell that has a center located on one side of the geometrical surface and a respective second cell that is a neighbor of the respective first cell and has a center located on the other side of the geometrical surface; and - transferring to each identified connection one or more respective parameters, each parameter being a value of a respective geological property of the geological surface, the method thereby configuring the geological simulation grid with respect to one or more geological properties of the geological surface; the geological simulation grid configured by the method being suitable, in a hydrocarbon production process, for: - performing flow simulation based on the geological simulation grid, the flow simulation thereby providing information on hydrocarbon flow in a reservoir environment; and - performing hydrocarbon production based on the result of the simulation. - providing a geometrical grid that conforms to a set of geological structures of a geological environment, the geometrical grid having cells and connections each between a respective pair of cells of the geometrical grid, the grid being unstructured and comprising non-neighbor connections; - providing a geometrical surface that represents a geological surface of the geological environment, the geological surface being not included in the set of geological structures, the geometrical surface being provided based on data obtained after a determination of the geometrical grid; - identifying geometrical structures of the geometrical grid representing a local intersection with the geometrical surface, within the set of all connections between pairs of cells, thereby identifying connections each between a respective pair of cells, each identified connection corresponding to a respective location of the geometrical surface and representing the local intersection, wherein the identifying includes determining pairs of cells each including a respective first cell that has a center located on one side of the geometrical surface and a respective second cell that is a neighbor of the respective first cell and has a center located on the other side of the geometrical surface; and - transferring to each identified connection one or more respective parameters, each parameter being a value of a respective geological property of the geological surface, the method thereby configuring the geological simulation grid with respect to one or more geological properties of the geological surface; - performing flow simulation based on the geological simulation grid, the flow simulation thereby providing information on hydrocarbon flow in a reservoir environment; and - performing hydrocarbon production based on the result of the simulation.