Abstract: A method for evaluating fluid flows within a heterogeneous formation, crossed by one or more geometric discontinuities, comprising generating a hybrid grid from a CPG type grid and from structured grids having application, for example, in simulation of hydrocarbon reservoirs. The first stage locally deforms a CPG type grid into a non-uniform Cartesian grid. These local grid cell deformations correspond to the change from a so-called “CPG” frame of reference to a so-called “Cartesian” frame of reference defined by the deformation. These deformations are then quantified and applied to the structured grids so as to shift to the “Cartesian” frame. A hybrid grid is then generated in the “Cartesian” frame from the two thus deformed grids. Finally, the hybrid grid is deformed to return to the “CPG” frame, prior to improving the grid quality, by optimization under quality control in the numerical scheme sense.

Abstract: A method, having application for hydrocarbon reservoir simulation, generates a hybrid grid, in order to carry out simulations in accordance with a defined numerical scheme, in three dimensions in a numerical scheme, of a heterogeneous formation crossed by at least one geometric discontinuity such as, an underground formation where at least one well has been drilled, or a fractured formation, by combining structured grids and unstructured grids. The hybrid grid includes a first structured grid for gridding the heterogeneous medium with second structured grids for gridding a zone around each discontinuity. A cavity of minimum size is automatically generated, with cells of the transition grid being an intermediate size between the size of the cells of the first grid and the size of the cells of the second grids.

Abstract: A method for evaluating fluid flows within a heterogeneous formation, crossed by one or more geometric discontinuities, comprising generating a hybrid grid from a CPG type grid and from structured grids having application, for example, in simulation of hydrocarbon reservoirs. The first stage locally deforms a CPG type grid into a non-uniform Cartesian grid. These local grid cell deformations correspond to the change from a so-called “CPG” frame of reference to a so-called “Cartesian” frame of reference defined by the deformation. These deformations are then quantified and applied to the structured grids so as to shift to the “Cartesian” frame. A hybrid g rid is then generated in the “Cartesian” frame from the two thus deformed grids. Finally, the hybrid grid is deformed to return to the “CPG” frame, prior to improving the grid quality, by optimization under quality control in the numerical scheme sense.

Abstract: Method of generating a hybrid grid, in order to carry out simulations in accordance with a defined numerical scheme, in three dimensions and admissible in the numerical scheme sense, of a heterogeneous formation crossed by one or more geometric discontinuities such as, for example, an underground formation where one or more wells have been drilled, or a fractured formation, by combining structured grids and unstructured grids. The hybrid grid is achieved by associating a first structured grid for gridding the heterogeneous medium with second structured grids for gridding a zone around each discontinuity. A cavity of minimum size, allowing the cells of the transition grid to have an intermediate size between the size of the cells of the first grid and the size of the cells of the second grids, is first generated, entirely automatically. A transition grid meeting the constraints of the numerical scheme used for simulation is then constructed.