US-12619000-B2 - Painting for geomodeling

US12619000B2US 12619000 B2US12619000 B2US 12619000B2US-12619000-B2

Abstract

The invention notably relates to a computer-implemented method of geomodelling. The method comprises providing a pseudo-stratigraphic grid. The pseudo-stratigraphic grid represents a reservoir and has pillars. Each pillar includes respective cells. Each cell has a respective stratigraphic layering index. The method then comprises providing a surface. The surface has a first region and a second region. The second region is complementary to the first region. The method also comprises, for each first pillar intercepted by the first region, determining a respective first stratigraphic layering value based on the relative position of the surface in the first pillar. The method also comprises, for each second pillar intercepted by the second region, determining a respective second stratigraphic layering value by interpolating and/or extrapolating first stratigraphic layering values. This provides an improved solution of geomodeling.

Inventors

Aurèle Forge
Pauline Durand Riard

Assignees

TOTALENERGIES ONETECH

Dates

Publication Date: 20260505
Application Date: 20200122

Claims (19)

1 . A process comprising one or more iterations of a computer-implemented method of geomodeling, the method comprising: providing a pseudo-stratigraphic grid representing a reservoir and having pillars, each pillar including respective cells, each cell having a respective stratigraphic layering index; providing a surface having a first region and a second region, the second region being complementary to the first region; for each first pillar intercepted by the first region, determining a respective first stratigraphic layering value based on relative position of the surface in the first pillar, the determining comprising computing a proportion of the first pillar above the surface; and for each second pillar intercepted by the second region, determining a respective second stratigraphic layering value by at least one of interpolating and extrapolating first stratigraphic layering values; the process further comprising performing one or more physical actions on a geological environment based on a result of the one or more iterations of the method.
2 . The process of claim 1 , wherein the second region presents a discontinuity.
3 . The process of claim 2 , wherein the reservoir comprises a geological structure which intersects the surface and yields the discontinuity.
4 . The process of claim 3 , wherein the geological structure is a fault or an unconformity.
5 . The process of claim 4 , wherein the pseudo-stratigraphic grid represents the fault or unconformity with a stair-step structure.
6 . The process of claim 1 , wherein the surface represents a horizon.
7 . The process of claim 1 , wherein the method further comprises smoothing the first stratigraphic layering values.
8 . The process of claim 1 , wherein interpolating first stratigraphic layering values is performed by linear interpolation or by gridding.
9 . The process of claim 1 , wherein the method further comprises, for one or more cells of the pseudo-stratigraphic grid, determining position of the cell relative to the surface based on a comparison of the respective stratigraphic layering index of the cell with the respective first stratigraphic layering value determined for the pillar of the cell if it is a first pillar, or with the respective second stratigraphic layering value determined for the pillar of the cell if it is a second pillar.
10 . The process of claim 9 , wherein the method further comprises constructing a geological unit based on the determined position of the one or more cells relative to the surface.
11 . A non-transitory data storage medium having recorded thereon a computer program comprising instructions for performing a computer-implemented method of geomodeling, the method comprising: providing a pseudo-stratigraphic grid representing a reservoir and having pillars, each pillar including respective cells, each cell having a respective stratigraphic layering index; providing a surface having a first region and a second region, the second region being complementary to the first region; for each first pillar intercepted by the first region, determining a respective first stratigraphic layering value based on relative position of the surface in the first pillar, the determining comprising computing a proportion of the first pillar above the surface; and for each second pillar intercepted by the second region, determining a respective second stratigraphic layering value by at least one of interpolating and extrapolating first stratigraphic layering values; the non-transitory data storage medium being configured to be used in a process, the process comprising performing one or more iterations of the method and performing one or more physical actions on a geological environment based on a result of the one or more iterations of the method.
12 . The data storage medium of claim 11 , wherein the second region presents a discontinuity.
13 . The data storage medium of claim 12 , wherein the reservoir comprises a geological structure which intersects the surface and yields the discontinuity.
14 . The data storage medium of claim 13 , wherein the geological structure is a fault or an unconformity.
15 . The data storage medium of claim 14 , wherein the pseudo-stratigraphic grid represents the fault or unconformity with a stair-step structure.
16 . A system comprising a processor coupled to a memory, the memory having recorded thereon a computer program comprising instructions for performing a computer-implemented method of geomodeling, the method comprising: providing a pseudo-stratigraphic grid representing a reservoir and having pillars, each pillar including respective cells, each cell having a respective stratigraphic layering index; providing a surface having a first region and a second region, the second region being complementary to the first region; for each first pillar intercepted by the first region, determining a respective first stratigraphic layering value based on relative position of the surface in the first pillar, the determining comprising computing a proportion of the first pillar above the surface; and for each second pillar intercepted by the second region, determining a respective second stratigraphic layering value by at least one of interpolating and extrapolating first stratigraphic layering values; the system being configured to be used in a process, the process comprising performing one or more iterations of the method and performing one or more physical actions on a geological environment based on a result of the one or more iterations of the method.
17 . The system of claim 16 , wherein the second region presents a discontinuity; and wherein the reservoir comprises a geological structure which intersects the surface and yields the discontinuity.
18 . The system of claim 17 , wherein the geological structure is a fault or an unconformity.
19 . The system of claim 18 , wherein the pseudo-stratigraphic grid represents the fault or unconformity with a stair-step structure.

Description

This application is the U.S. National Stage of International Application No. PCT/IB2020/000076, filed Jan. 22, 2020, which designates the U.S., and published in English. The entire teachings of the above application is incorporated herein by reference. FIELD OF THE INVENTION The invention relates to the field of geomodeling, and more particularly to computer-implemented methods, programs and systems for performing geomodeling based on a pseudo-stratigraphic grid representing a reservoir, for example for the purpose of geological simulations in the context of oil and/or gas production. BACKGROUND Geomodeling (or geologic modeling) refers to methods for determining data representing a geological environment, including for example determining data configured for geological simulation and/or performing geological simulation. Geological simulation refers to all techniques for performing computer simulations related to a geological environment. These techniques assist actors by providing them with computerized representations of real, estimated or predicted states and/or processes related to the geological environment. Geological simulation techniques include geostatistical simulations. Geostatistical simulations may for example determine a distribution of petrophysical properties of the reservoir, e.g. including facies, porosity, permeability, and/or fluid saturations. Geological simulation techniques also include dynamic simulations, such as hydrocarbon flow simulation (which may simply be referred to as “flow simulation”). Flow simulation provides useful information as to how hydrocarbons (i.e. gas and/or oil) flow in a reservoir environment. Flow simulation may for example represent real, estimated or predicted pressure, saturations, flow paths, flow rates, flowing compositions, and/or evolutions of these quantities over time. In many existing solutions, geological simulations are performed based on geological simulation grids (also referred to as “geomodels”). A geological simulation grid comprises a geometrical grid which represents a geological environment, such as a hydrocarbon reservoir. The geometrical grid may conform to shapes of geological structures, such as horizons, fault surfaces, channels and/or reservoirs. For example, horizons may correspond to layer structures of the geometrical grid and fault surfaces may correspond to stair-stepped structures of the geometrical grid. Geological simulation grids may further comprise parameters (also referred to as “properties”) which represent geological properties of the geological structures, such as flow parameters, and which are assigned to geometrical structures of the geometrical grid. A geological simulation grid may be inputted to a simulator which performs the simulation, according to the shapes of the geometrical grid and/or to the values of the geological properties conveyed by the parameters. Because of the size of the geological environments and the numbers of geological structures at stake and mesh quality requirements on one side, and the geometric constraints required for simulations, such as cell isotropy and cell orthogonality, designing a geological simulation grid is a tedious task. Another constraint for minimizing the simulations time is the total number of cells. Geometrical grids may indeed comprise more than ten million of cells in some situations. For these reasons, only part of the available geological information is used at the time of the initial design. Also, approximations and errors are made. As a consequence, the result of an initial design is most often inaccurate, in the sense that simulations performed on the basis of a designed geological simulation grid are most often inaccurate. In order to improve accuracy in an efficient manner, existing solutions offer tools for configuring the geological simulation grid (i.e. adding new parameters to the grid and/or modifying existing parameters assigned to geometrical structures of the grid), rather than modifying the geometrical grid shape. Some solutions propose to represent the reservoir with a geometrical grid which is a pure stratigraphic grid, in other words, a grid perfectly consistent with a stratigraphy and which is either hexahedral or tetrahedral or any others 3D closed polygons. When the grid is hexahedral, perfect consistency with the stratigraphy results in cell distortions. When the grid is tetrahedral, such as proposed by software Petrel and SKUA (registered trademarks), the cell-to-cell topology is complex and physics in more difficult to represent. In any cases, simulations perform poorly due to time-consuming computations and/or are inaccurate due to the distortions or topology complexity. Some other solutions use pseudo-stratigraphic grids in order to represent a reservoir. Pseudo-stratigraphic approaches enable to model complex geology (e.g. faults and/or complex stratigraphy) with classical hexahedral grids. The use of the pseudo-stratigraphic grid indeed make