Method implemented by computer for adaptation of a lattice model of a geological subsurface obtained using measurements of said geological subsurface for comparison to a target, the adapted lattice model being used in the determination of the reserves of gas or of hydrocarbons contained in a reservoir, said model comprising a plurality of reference interfaces comprising an order, each reference interface being associated with a target interface in said target, wherein the method comprises: - for at least one couple of successive interfaces in the order of the plurality of interfaces formed by a first reference interface and a second reference interface, the model comprising between said first interface and said second interface a plurality of alignment of cell corners, these alignments forming edges of cells, each corner having initial coordinates in the model and for each current alignment among said plurality of cell corners: -- determination of a first intersection between the current alignment and said first reference interface; -- determination of a second intersection between the current alignment and said second reference interface; -- determination of a third intersection between the current alignment and the target interface associated with said first reference interface; -- determination of a fourth intersection between the current alignment and the target interface associated with said second reference interface; -- modification of the coordinates for each current corner of the alignment as a function of the initial coordinates of said current corner, of the first intersection, of the second intersection, of the third intersection and of the fourth intersection, the modified coordinates of said current corner being on the current alignment; - for the at least one pair of successive interfaces, the corners of said alignments comprised between said first interface and said second interface having a serial number in each alignment: - for each current serial number, identification of an intermediate interface formed by cell sides, said sides having, as corners, corners of said current serial number; - for each intermediate interface and for each current corner of said current interface, second modification of the coordinates of said current corner according to the current coordinates of said current corner and according to the current coordinates of the corners distant by less than one window value from the current corner. - for at least one couple of successive interfaces in the order of the plurality of interfaces formed by a first reference interface and a second reference interface, the model comprising between said first interface and said second interface a plurality of alignment of cell corners, these alignments forming edges of cells, each corner having initial coordinates in the model and for each current alignment among said plurality of cell corners: -- determination of a first intersection between the current alignment and said first reference interface; -- determination of a second intersection between the current alignment and said second reference interface; -- determination of a third intersection between the current alignment and the target interface associated with said first reference interface; -- determination of a fourth intersection between the current alignment and the target interface associated with said second reference interface; -- modification of the coordinates for each current corner of the alignment as a function of the initial coordinates of said current corner, of the first intersection, of the second intersection, of the third intersection and of the fourth intersection, the modified coordinates of said current corner being on the current alignment; -- determination of a first intersection between the current alignment and said first reference interface; -- determination of a second intersection between the current alignment and said second reference interface; -- determination of a third intersection between the current alignment and the target interface associated with said first reference interface; -- determination of a fourth intersection between the current alignment and the target interface associated with said second reference interface; -- modification of the coordinates for each current corner of the alignment as a function of the initial coordinates of said current corner, of the first intersection, of the second intersection, of the third intersection and of the fourth intersection, the modified coordinates of said current corner being on the current alignment; - for the at least one pair of successive interfaces, the corners of said alignments comprised between said first interface and said second interface having a serial number in each alignment: - for each current serial number, identification of an intermediate interface formed by cell sides, said sides having, as corners, corners of said current serial number; - for each intermediate interface and for each current corner of said current interface, second modification of the coordinates of said current corner according to the current coordinates of said current corner and according to the current coordinates of the corners distant by less than one window value from the current corner.