Although simple to use, conventional cartesian grids, commonly employed in petroleum reservoir simulation, cannot produce accurate modeling of most of the aforementioned geometric features. Stanfords general purpose research simulator gprs serves as the base for the new framework. The examples include the famous quarterfive spot problem, a. Knutandreas lie an introduction to reservoir simulation using matlab user guide for the matlab reservoir simulation. Geometry modeling grid generation stanford university. This work presents the implementation of an ebfvm formulation using unstructured grids for tridimensional compositional reservoir simulation in conjunction with an impec approach. Purchase basic structured grid generation 1st edition. An unstructured gridding method for simulating faulted. Structured versus unstructured pebi grids in reservoir modeling and simulation bogdan balan, schlumberger gss abstract application of unstructured irregular grids in reservoir simulation is one of the most important concepts that have been developed in the past decade 1. On this unstructured fine grid, msdfm imposes independent unstructured coarse grids for the fracture and matrix domains.
Its flexibility of grid generation and enhanced simulation accuracy have gained popularity in reservoir simulation, especially when modeling reservoir with complex wells and faults. Within the context of petroleum reservoir simulation, mpfa methods are commonly considered, as they are controlvolume based, locally conservative, introduce only one unknown per block, are applicable for multiphase flow problems, and allow the use of grids with general geometry. Grid as in figure 33, but with fault 106 figure 36. A computer implemented system and method for parallel adaptive data partitioning on a reservoir simulation using an unstructured grid includes a method of simulating a reservoir model which. Though this concept was introduced to the petroleum industry as. For reservoir simulation using the blackoil model on unstructured grids, only the fully implicit solution method has been used for solving the governing.
Following an introduction of unstructuredgrid methods in reservoir simulation, the gridding algorithm is discussed in details. Threedimensional geological boundary aligned unstructured grid generation, and cvdmpfa flow computation. Techniques for modeling complex reservoirs and advanced. Introduction webster defines simulate as to assume the appearance of without reality. The resulting unstructured simulation grid is shown in fig. The breakthrough curves obtained with the highresolution geological scale and largescale reservoir simulation have been compared. Reservoir simulation is an area of reservoir engineering that, combining physics, mathematics, and computer programming to a reservoir model allows the analysis and the prediction of the fluid behavior in the reservoir over time it can be simply considered as the process of mimicking the behavior of fluid flow in a. The development of a generalpurpose reservoir simulation framework for coupled systems of unstructured reservoir models and advanced wells is the subject of this dissertation. Reservoir simulation is an area of reservoir engineering in which computer models are used to predict the flow of fluids typically, oil, water, and gas through porous media under the model in the broad scientific sense of the word, they understand a real or mentally created structure that reproduces or reflects the object being studied. Recently he is developing a new methodology for solving geomechanics coupled with fluid flow. Rubis is a 3d, 3 phase, multi purpose numerical modeler which sits somewhere between single cell material balance and massive fullfield simulation models.
The first application of unstructured grids in the petroleum reservoir area. Class for volume of interest voi in the cornerpoint grid cpg or cartesian grid which generates the geometrical information of cpg or cartesian grid in voi and constructs the unstructured voi grid. Applications for petroleum reservoir simulation and reservoir well coupling are key activities. An introduction to reservoir simulation using matlabgnu octave. Abstract unstructured gridding has become an important subject matter in reservoir simulation. The grid processing routine that causes your problems was written by a former master student. We also outline the basic solver used to compute timeofflight and tracer partitions. A common requirement in reservoir simulation is an increased level of detail around an item of interest such as a well. Heriot watt university, reservoir simulation course grid oil and gas reservoirs structure is a set of geological horizons representing bedding planes two related issues are involved in choosing a grid for reservoir simulation. Basics of reservoir simulation with the eclipse reservoir. Rozon 1989 used the cvfem control volume finite element method, developed originally by. Can the origin of the coordinates be placed in the center.
The use unstructured meshes in reservoir simulation date from the 1980 decade. Jpt new modeling and simulation techniques optimize. A wide variety of multiscale methods have been proposed in the literature to reduce. Structured versus unstructured pebi grids in reservoir. The grid lines are curved to fit the shape of the boundaries unstructured grids. The book then introduces unstructured grid generation by explaining the basics of delaunay triangulation and advancing front techniques. Using unstructured grids for modeling complex discrete.
A popular unstructured grid is the perpendicular bisector pebi grid. Simulation of petroleum reservoir performance refers to the construction and operation of a model whose behavior assumes the appearance of actual reservoir. Transfinite interpolation, morphing, pde based, etc. Highquality grids guarantee the fidelity of a reservoir model and keep the flow calculations simple. In this study, we propose a 3d unstructured grid, the generalized prism grid gpg, to model reservoirs with complicated geological geometries, including horizons, pinchouts, faults, fractures, and bore holes. Basics of reservoir simulation with the eclipse reservoir simulator. Grid generation techniques structured grids ordered set of locally orthogonal lines several techniques can be used to map a computational domain into a physical domain.
The grid generation by algebraic methods is based on mathematical interpolation function. In combination, these techniques provide a prototype workflow for the construction of unstructured simulation models. Embedded discrete fracture modeling and application in. Grid generation is critical to numerical reservoir simulations.
This is followed by simulation examples, which includes a fullfield compositional simulation example of a faulted gascondensate reservoir completed with many deviated and horizontal wells. If a cornerpoint grid representation is used, oblique features must be converted into a series of stair step. Modeling polymer flood in an unstructured grid simulator. Reservoir simulation tool is an amazing product of an integrated effort of geosciences, reservoir and production engineering, petrophysics, computer science and economics. This is followed by simulation examples, which includes a fullfield compositional simulation example of a faulted gascondensate reservoir.
Unstructured grid adaptation for multiscale finite volume. Sepehnoori 3d reservoir simulation using unstructured grid from figure 5, it is possible to verify that the saturation field at upper and lower surface of the reservoir obtained with both grid configurations are in good match. This is frequently obtained in structured grids by local grid refinement, replacing a set of cells in the original grid by a finer grid fig. Sagd in a naturally fractured reservoir with a discrete fracture network modeled through a series of unstructured local grid refinements to capture flow through fractures.
The generation of accurate and reliable unstructured 3d models for reservoir simulation remains a challenge. Kinetix reservoir centric stimulationtoproduction software is the only hydraulic fracturing design software that employs a seamless, comprehensive seismicto simulation workflow for the multilevel optimization of unconventional or conventional reservoirs. The total number of the grid cells was close to 10,000,000, a size that presents a huge challenge for simulation. The inserted grid may be cartesian center or radial upper left. This paper describes the development of a comprehensive polymer flood modeling capability within a reservoir simulator that uses an unstructured grid framework. Can the origin of the coordinates be placed in the center of the reservoir in mrst. In this paper, new developments for grid generation, upscaling and streamline simulation for such models are described. Multiphase fluid flow in porous and fractured reservoirs. It replaces neither, but does much of the work of both.
Embedded discrete fracture modeling and application in reservoir simulation is an essential reference for anyone interested in performing reservoir simulation of conventional and unconventional fractured reservoirs. The reservoir simulation chapter in the 1987 edition of the petroleum engineering handbook included a general description of reservoir simulation models, a discussion related to how and why they are used, choice of different types of models for differentreservoir problems, and reliability of simulation results in the face of model assumptions and uncertainty in reservoirfluid and rockdescription parameters. Us8437996b2 parallel adaptive data partitioning on a. It is done by using known functions in one, two or three dimensions taking arbitrary shaped regions. A basic edfm approach using cartesian grids and advanced edfm approach using corner point and unstructured grids will be covered.
The invention relates to a method for automatically designing an optimum simulation grid. A computer implemented system and method for parallel adaptive data partitioning on a reservoir simulation using an unstructured grid includes a method of simulating a reservoir model which includes generating the reservoir. This paper presents new results for applying the sequential solution method to the blackoil reservoir simulation with unstructured grids. The prolongation operators are computed numerically by solving localized. Accuracy with which the geological description of the reservoir is matched. Transmissibility upscaling on unstructured grids for. It cannot be outputted directly to a reservoir simulator. Figure 9 shows that the results of geological highresolution scale simulation and largescale reservoir simulation with the local transmissibility upscaling method are similar.
Incompressible solvers for singlephase flow chapter 5. Grid refinement proportions are still in progress in order to reduce the simulation time which is sensitive to the perforated cell size grid size is highly reduced 1 million cells versus 28 millions and global results in terms of production profiles between the structured and the unstructured simulation. Cell indices and coordinate indices in a structured grid 23. The book also teaches grid coarsening, upscaling, and flow diagnostics. The computational domain might not be rectangular, but for the sake of. Reservoir simulation is a widely used method by oil and gas companies to expand and develop new methods, recovery projects and locations of infill wells. The inverse of the matrix for the original unstructured grid. Natural fractured reservoir engineering phdg textbooks in preparation, intended to be issued during 2015.
The matlab reservoir simulation toolbox mrst sintef. Naturally fractured hydrocarbon reservoir simulation by. Multiphase fluid flow in porous and fractured reservoirs discusses the process of modeling fluid flow in petroleum and natural gas reservoirs, a practice that has become increasingly complex thanks to multiple fractures in horizontal drilling and the discovery of more unconventional reservoirs and resources. One can build simple numerical models intuitively with no special training. Maliska is devoted to the development of numerical methods for the solution of navier stokes and darcys equations using the ebfvmelementbased finite volume methods with hybrid unstructured grids. Unstructured reservoir simulation grid the detailed geological grid created on the basis of the uvt transform mallet et al. The matlab reservoir simulation toolbox user group group. The fully implicit solution method has been successfully applied to reservoir simulation with unstructured grids. Unfortunately, nobody from the mrst team at sintef know the inner workings of this code.