111 results about "Unstructured mesh" patented technology

A targeted heterogeneous medium in the form of an underground layered formation is gridded into a layered structured grid or a layered semi-unstructured grid. The structured grid can be of the irregular corner-point-geometry grid type or the simple Cartesian grid type. The semi-unstructured grid is areally unstructured, formed by arbitrarily connected control-volumes derived from the dual grid of a suitable triangulation; but the connectivity pattern does not change from layer to layer. Problems with determining fluid movement and other state changes in the formation are solved by exploiting the layered structure of the medium. The techniques are particularly suited for large-scale simulation by parallel processing on a supercomputer with multiple central processing units (CPU's).

A “near wellbore modeling” software will, when executed by a processor of a computer, model a localized area of a reservoir field which surrounds and is located near a specific wellbore in the reservoir field by performing the following functions: (1) receive input data representative of a reservoir field containing a plurality of wellbores, (2) establish a boundary around one specific wellbore in the reservoir field which will be individually modeled and simulated, (3) impose an “fine scale” unstructured grid inside the boundary consisting of a plurality of tetrahedrally shaped grid cells and further impose a fine scale structured grid about the perforated sections of the specific wellbore, (4) determine a plurality of fluxes/pressure values at the boundary, the fluxes/pressure values representing characteristics of the reservoir field located outside the boundary, (5) establish one or more properties for each tetrahedral cell of the unstructured grid and each cylindrical grid cell of the structured grid, (6) run a simulation, using the fluxes/pressure values at the boundary to mimic the reservoir field outside the boundary and using the fine scale grid inside the boundary, to thereby determine a plurality of simulation results corresponding, respectively, to the plurality of grid cells located inside the boundary, the plurality of simulation results being representative of a set of characteristics of the reservoir field located inside the boundary, (7) display the plurality of simulation results which characterize the reservoir field located inside the boundary, and (8) reintegrate by coarsening the grid inside the boundary, imposing a structured grid outside the boundary, and re-running a simulation of the entire reservoir field.

A method of generating a hybrid grid allowing modelling of a heterogeneous formation crossed by one or more pipes such as, for example, an underground formation where one or more wells have been drilled, in order to form a representative model, for example of fluid flows in the formation in accordance with a defined numerical pattern is disclosed. The method comprises associating a first structured grid for gridding of the heterogeneous medium regarding discontinuities thereof with a second structured, radial type grid for gridding of a zone around each pipe or well, which allows better constraints linked with flows in the zone, and transition of non-structured grids that are interposed between the first grid and each second well grid. Various grids are combined, each with its own formation, representation and exploration methods, structured grids which are advantageous in facilitating control and comprehension of the reservoir images formed and more flexible non-structured grids for gridding of complex zones. An application is simulation of hydrocarbon reservoirs.

A method of generating a hybrid grid 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 non-structured grids in order to carry out simulations in accordance with a defined numerical pattern is disclosed. Hybrid gridding is performed by associating a first structured grid (G1) for gridding of the heterogeneous medium considering discontinuities thereof with second structured, radial type grids (G2) for gridding of a zone around each pipe or well, which allows better consideration of constraints linked with flows in the zone. In order to connect the first grid of the medium and the second well grids, non-structured transition grids (G3) are interposed there between. A power diagram technique is used, which is particularly advantageous in that it allows appropriate connection of non-regular structured grids. An application is hydrocarbon reservoir simulation.

Example embodiments utilize machines to model reservoir geometry having geological layers as 2.5D unstructured grids. Example embodiments include program products to simulate a reservoir by generating a reservoir data system, performing a numerical fluid flow simulation, and visualizing the simulation. Data system embodiments include data structures to model a reservoir geometry as laterally unstructured two-dimensional (2D) grids and associated layer depths defining z-lines to thereby define a 2.5D unstructured grid, including datasets for: vertices of the grid cells for the future grid top and bottom surfaces, a number and listing of vertices for each grid cell, cell center coordinates, and vertex adjacency information using a compressed sparse row format. Computer-implemented methods include projecting external and internal boundaries onto a future grid surface; generating 2D unstructured, e.g., Voronoi, grids, for the top and bottom surfaces; and generating z-lines of depths corresponding to reservoir layers to thereby generate 2.5D unstructured grids.

The invention provides a digital ship model plane motion organization experimental method based on computation fluid dynamics CFD software FLUENT. The method includes applying a FLUENT pre-process software GAMBIT to establish a research object model and a control domain; arranging a triangle grid on the model surface, then arranging a unstructured grid in the control domain; setting the boundary condition, joining an user-defined function UDF document, introducing dynamic grid technology, using a finite volume method based on the complete unstructured grid, realizing a pure swaying movement, a pure rising and falling movement, a pure oscillatory movement, a pure pitching movement and a pure rolling movement carried on by a plane motion organization experiment; applying a science computation software MATLAB to do Fourier expansion of a force and a moment coefficient obtained by the FLUENT, being fitted by EXCEL least squares method, obtaining a hydrodynamic force coefficient of a vertical plane and a horizontal plane as well as the related hydrodynamics analysis by dimensionless. The invention carries on the digit plane motion organization experiment using the CFD software, can satisfy the request of hydrodynamic force data in the design initial period of a submersible.

A linear solver methodology is applied to reservoir data to solve for large system of equations arising from high-resolution reservoir simulation of giant oil fields with minimal upscaling using either structured grids or unstructured grids. Full geologic complexity and discontinuities at the resolution desired for accurate simulation results may be taken into account. A general unstructured method is provided, so that very complex flow geometry near multi-lateral wells can be modeled.

Unstructured grids are automatically constructed in a domain containing complex internal boundaries. Simulation grids are constructed for reservoirs or fields which contain complex fault planes. Reconciling among generated fault grid-points and other reservoir/field grid-points is performed, enabling the use of unconstrained Delaunay triangulation. High-quality orthogonal unstructured grids are provided with good convergence properties for reservoir simulation.

The invention relates to a method for assessing a tide energy resource through a numerical simulation of sea model. The technological steps are as follows: a target sea area is selected; sea chart splicing work of the target sea area is completed, and a high-precision terrain data product of the target sea area is manufactured; water depth terrain data measured through a field investigation are combined with satellite data, so that water depth terrain data of the target sea area are obtained; non- structural grid is performed on a calculation area of the target sea area, and the sea model is constructed; number value simulation calculation is performed with the sea model; a simulation calculation result and actually measured data are compared and verified; the energy flow density is calculated; the standing stock is calculated by selecting a section with a larger energy flow density; the developable tide energy power and the resource category are acquired according to the obtained standing stock; and an assessment result is displayed through a visualization technology. The method provides an important way for accurately assessing the tide energy level of the target sea area and solving the problem that the energy in coastal and sea island areas of our country is short.

The invention provides a two-dimensional numerical simulation method of urban surface runoff. After obtaining urban topography and geomorphology data, the triangular unstructured mesh is used to discrete the computational area of the urban area. The area where the building is located does not participate in dissection, and its contour line is used as the control line of mesh dissection. Each rainwater pipe of the building is connected with the ground through the confluence connecting edge. Firstly the method calculates the confluence area of each rainwater pipe, and then calculates the discharge process of each rainwater pipe. Two-dimensional Godunov model is used to simulate the rainwater outflow process. The rainfall in the surface grid element is treated as the source term in the model,and the rainwater outflow process is regarded as the flow boundary condition of the element corresponding to the connecting edge. The invention fully considers the characteristics of building confluence in the urban area, which can not only ensure the mass conservation characteristic of the whole urban area during flood calculation, but also consider the influence of the water flow momentum at the outlet of the rain pipe on the surface runoff, thus overcoming the shortcoming that the existing urban flood and waterlogging model can not consider the building confluence process, and improving the calculation accuracy.

The invention discloses a nuclear reactor core physical and thermal coupling simulation method, which comprises the following steps of: firstly, establishing a computational domain unstructured grid model by adopting Fluent pretreatment software, and then importing the grid model into Fluent to establish an example; extracting grid information and flow field data in a Fluent example by adopting auser-defined function function of Fluent software, and automatically generating an input file required by MCNP5 calculation; controlling MCNP5 to complete calculation of a neutron physical field by means of a user-defined function function of Fluent, analyzing the output file of the MCNP5, and extracting fission power data of a nuclear fuel region; transmitting the fission power into Fluent software and executing calculation; after initial convergence of Fluent calculation, regenerating an MCNP5 input file by using the user-defined function of the Fluent, calling the MCNP5 again to calculate fission power data, and transmitting the fission power data to the Fluent; and repeating the above steps until Fluent is finally converged. According to the invention, physical and thermal coupling canbe conveniently realized, and a foundation is laid for research of a numerical reactor.

The invention discloses a method used for simulating fluid flow, and the scope of the fluid flow comprises obstacles represented by irregular boundaries; the method is characterized in that: a structured grid of initial physical space is built, and evolved into a complex structured grid by applying treatment to the irregular boundaries one by one, and every irregular boundary is inserted into the complex structured grid as a zero iso-surface to obtain a complex invisible structured grid (CISgrid for short); a unit vertex of the CISgrid is used as a computational node, a finite difference method is adopted to carry out fluid flow numerical simulation according to node connected regulation. According to effective regulation inside the CISgrid, post-treatment of the fluid flow numerical simulation is carried out. The method solves the problem that the irregular boundaries can not be effectively treated when the fluid flow simulation is directly carried out with the structured grid and the finite difference method, avoids the problem of the introduction of the complex structured grid by the adaptation of an unstructured grid and the complex numerical computation based on the unstructured grid, and effectively improves the efficiency of the fluid flow simulation.

The present invention is a marine controlled source electromagnetic method finite element forward method of anisotropic media. The method comprises: firstly, setting a reference electrical conductivity, wherein three non-zero diagonal elements of the reference electrical conductivity are electrical conductivities in the direction of three main axes: x, y, z; next, setting three Euler rotation angles, and after three times of Euler rotation, obtaining an electrical conductivity tensor model in any direction; then starting from Maxwell equations, obtaining a finite element equation that is satisfied by magnetic vector potential and scalar potential under Coulomb regulations on a condition that the electrical conductivity presents anisotropy; then, performing discrete segmentation on a research region by using a non-structural grid, so that a complicated geoelectric model can be constructed; combining an incomplete LU discomposition pre-condition factor with an IDR(s) algorithm, so as to realize efficient and precise solution of a large sparse linear equation; and finally, deriving vector potential and scalar potential of a secondary field by using weighted moving least squares solution, to obtain each component of an electromagnetic field. The method provided by the present invention has excellent universality and can be promoted for electromagnetic method numerical value simulation with complicated electrical conductivity distribution and high precision.

Systems and methods for providing a reservoir simulation are based on data from an unstructured grid using a structured grid reservoir simulator. Exemplary methods comprise obtaining an unstructured grid reservoir model comprising a reservoir model discretized on an unstructured grid. A virtual structured grid is defined for the unstructured grid reservoir model. The unstructured grid is aligned with the virtual structured grid by adding cells to the unstructured grid to make the unstructured grid and virtual structured grid have the same number of cells. The virtual structured grid may be represented in the unstructured grid. Structured grid reservoir simulator input data comprising reservoir model data assigned to the virtual structured grid is prepared based on reservoir model data in the unstructured grid model. A structured grid reservoir simulation is performed using the structured grid reservoir simulator input data to produce a reservoir simulation.

The invention provides an embedded discrete fracture model-based fractured well modeling and simulation method. The method includes: dividing a bed rock system orthogonal coarse meshes, and extracting coarse mesh nodes and fracture information; dividing the system into a bed rock system and a fracture system, and establishing a flow mathematical model for the bed rock system and the fracture system each; establishing a corresponding embedded discrete fracture net model; establishing a bed rock system numerical calculation format based on a simulation finite difference method; analyzing the numerical calculation format of fractures in bed rocks in three different embedded manners; establishing a numerical calculation format of an embedded discrete fracture net system based on a control volume finite difference method; and serving the fracture system as a source term of the bed rock system, and establishing an embedded discrete fracture flow mathematical model by coupling the fracture system and the bed rock system. The embedded discrete fracture model-based fractured well modeling and simulation method can avoid a complicated unstructured mesh generation process, and improve the accuracy and the high efficiency of a fractured well fracture description and simulation method.

The invention relates to a method for architectural design by utilizing simplified models and unstructured grids. The method includes: necessarily simplifying cumbersome steps during the architectural design; making the simplified building models through software inside a building and taking the detected building as a large space grid; inputting building information and environment information into a computer for simulation of the building environment and the humidity environment to acquire data of the unstructured grids of the whole building; calculating each space building grid according to the acquired data; analyzing functional arrangement of the building as required and integrally concentrating functional zones identical in attribute as far as possible to enable the building to be standard and vertical. By the method, convenience in observation of an internal structure of the building facilitates knowledge of external environment characteristics, so that a designer can observe, study and work out good works conveniently and rapidly.