Abstract: A method of generating a volumetric data structure of a subsurface region, including: obtaining, with a computer, a volume segment of the subsurface region, wherein the volume segment is bounded by a first horizon and a second horizon, and by a plurality of lateral surfaces formed by faults and boundaries of a geological model corresponding to the subsurface region; obtaining, with the computer, an isomorphic triangulation of the first horizon of the volume segment; deforming, with the computer, the isomorphic triangulation of the first horizon of the volume segment to fit a boundary of the second horizon of the volume segment; after the deforming, creating, with the computer, a template grid from the first horizon of the volume segment and the second horizon of the volume segment; generating, with the computer, layer sections from the template grid by cutting the template grid by lateral surfaces of the volume segment; and generating, with the computer, the volumetric data structure of the subsurface reservo