Computer implemented method for manipulating a mesh for the discretization of a reservoir domain modeled by a geophysical model, a fluid model or both models, wherein the geophysical model comprises the mechanical and rock properties and the fluid model comprises the fluid properties and, both models comprise geophysical entities of the reservoir; the information data of geophysical entities being retrieved from the reservoir, the method comprising: a) generating, via a computer system, a geophysical model, a fluid model or both models (GM, FM), said models (GM, FM) comprising geophysical entities in the domain (Ω); b) generating, via a computer system, a partition of the domain (Ω), the partition comprising a plurality of cells limited by a boundary, each cell comprising vertices and, each cell has a common boundary with adjacent cells; c) generating for each cell, via a computer system, a numerical mesh discretizing the cell, said numerical mesh comprising nodes at least in the vertices of the cell; d) providing the mesh resulting from the union of the meshes of the plurality of cells, that is, the result of a consolidation process removing the duplicated nodes of adjacent cells and to store the nodes in the global mesh only once wherein duplicated nodes are at locations separated by a distance lower than a predetermined threshold; wherein the cells of the partition, have a shape that, when a cell is subdivided into smaller sub-cells, said sub-cells have the same topology than the original, and wherein the set of cells are rectangles if the domain (Ω) is a 2D-domain or hexahedrons if the domain (Ω) is a 3D-domain, with the edges/faces parallel two by two; the method being adapted for the simulation of oil and gas reservoirs, reproducing an exploitation process as many times as needed for identifying the optimal exploitation plan, said optimal plan being the exploitation plan of the exploitation process. the method comprising: a) generating, via a computer system, a geophysical model, a fluid model or both models (GM, FM), said models (GM, FM) comprising geophysical entities in the domain (Ω); b) generating, via a computer system, a partition of the domain (Ω), the partition comprising a plurality of cells limited by a boundary, each cell comprising vertices and, each cell has a common boundary with adjacent cells; c) generating for each cell, via a computer system, a numerical mesh discretizing the cell, said numerical mesh comprising nodes at least in the vertices of the cell; d) providing the mesh resulting from the union of the meshes of the plurality of cells, that is, the result of a consolidation process removing the duplicated nodes of adjacent cells and to store the nodes in the global mesh only once wherein duplicated nodes are at locations separated by a distance lower than a predetermined threshold; a) generating, via a computer system, a geophysical model, a fluid model or both models (GM, FM), said models (GM, FM) comprising geophysical entities in the domain (Ω); b) generating, via a computer system, a partition of the domain (Ω), the partition comprising a plurality of cells limited by a boundary, each cell comprising vertices and, each cell has a common boundary with adjacent cells; c) generating for each cell, via a computer system, a numerical mesh discretizing the cell, said numerical mesh comprising nodes at least in the vertices of the cell; d) providing the mesh resulting from the union of the meshes of the plurality of cells, that is, the result of a consolidation process removing the duplicated nodes of adjacent cells and to store the nodes in the global mesh only once wherein duplicated nodes are at locations separated by a distance lower than a predetermined threshold; wherein the cells of the partition, have a shape that, when a cell is subdivided into smaller sub-cells, said sub-cells have the same topology than the original, and wherein the set of cells are rectangles if the domain (Ω) is a 2D-domain or hexahedrons if the domain (Ω) is a 3D-domain, with the edges/faces parallel two by two; the method being adapted for the simulation of oil and gas reservoirs, reproducing an exploitation process as many times as needed for identifying the optimal exploitation plan, said optimal plan being the exploitation plan of the exploitation process.