Abstract in the last decade, unstructured grids have been a very important step in the development of petroleum reservoir simulators. The construction of simulation grids, such as the unstructured cutcell grid shown in fig. A control volume scheme for flexible grids in reservoir simulation, spe 37999, in. Unstructured grids for modeling reservoirs chevron u. Pdf this paper presents a 2d implementation of an elementbased finitevolume formulation ebfvm using triangles, quadrilaterals, or a. This tool can be used to provide the flowbased assessment of the coarse model. This new simulator is designed to handle miscible gas flooding, chemical flooding, and thermal flooding processes for conventional and unconventional reservoirs.
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. Although simple to use, conventional cartesian grids, commonly employed in petroleum reservoir simulation, cannot produce accurate modeling of most of the aforementioned geometric features. We encourage you to also look at the many publications that use mrst. Complex, unstructured grids with many obscure challenges. 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. We first present the basic issues and workflow for reservoir simulation with unstructured grids. The convergence characteristic of fmm on unstructured grids is investigated. T1 2d compositional reservoir simulation using unstructured grids in heterogeneous reservoirs jo blucher mechanical engineering proceedings vl 1 is 1 sp 1455 ep 1474 py 2014 t2 10th world congress on computational mechanics au b. In this talk, we present a new integrated approach to reservoir modeling and simulation by using unstructured grids and other novel modeling techniques. Geometry approaches, are widely used in the reservoir simulation. It requires a 3d unstructured grid approach that allow an accurate representation of the near well flow and preserving geological accuracy and offering flexible resolution control. The structure of unstructured grids centre for computational.
Pebigrids used for reservoir simulations are discussed by verma and. The generation of accurate and reliable unstructured 3d models for reservoir simulation remains a challenge. In the new approach the geological model gm of the reservoir is first generated, using square or cubic grid. This is constructed around a set of solution points that need have no particular indexing scheme. Discretization methods are proposed for controlvolume formulations on polygonal and triangular grid cells in two space dimensions. The method employs unstructured grids using triangular andor quadrilateral elements, such that complex re.
Hybrid mesh generation for reservoir flow simulation in cpg grids 419 cpg grid, the cell faces are aligned with the geological structures of the real reservoir. Structured versus unstructured pebi grids in reservoir modeling. Fulltensor finitevolume schemes with flow based grids. For simpler problem such as airfoil single element or an isolated wing, structured grids are generally more accurate per unknown than unstructured. Pdf unstructured gridding and consistent discretizations for. Anisotropic mesh adaptation for 3d anisotropic diffusion problems with application to fractured reservoir simulation. A streamline simulation technique for the efficient modeling of flow and transport on unstructured grids is presented. Pdf this paper presents a 2d implementation of an elementbased finite volume formulation ebfvm using triangles, quadrilaterals, or a. We have exploited this concept in order to develop a new method for the generation of unstructured computational grids.
This paper presents new results for applying the sequential solution method to the blackoil reservoir simulation with unstructured grids. Opensource matlab implementation of consistent discretisations on complex grids. Upscaled unstructured computational grids for efficient simulation of flow in fractured porous media. A popular unstructured grid is the perpendicular bisector pebi grid. Introduction to reservoir simulation as practiced in industry.
An extension for unstructured grids is described that leads to a general symmetric positive definite discretization matrix for both quadrilateral and triangular grids. This work presents the implementation of an ebfvm formulation using unstructured grids for tridimensional compositional reservoir simulation in conjunction with an impec approach. The matlab reservoir simulation toolbox mrst sintef. Rapid simulation of naturally fractured unconventional.
Pdf a tvd scheme for 3d unstructured grids applied to. Fault modelling aspects using unstructured grid with a. Corner point grids and pillar based unstructured grids do not provide an effective workflow for translating earth models into simulation models. Using unstructured grids for modeling complex discrete fracture. In this work a numerical model for simulating petroleum reservoirs using the elementbased finite volume method ebfvm is presented. Unlike structured grids, unstructured grids require a list of the connectivity which specifies the way a given set of vertices make up individual elements see graph data structure. Application of the unstructured grids in the numerical.
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. Reservoir simulation is efficiently computed based on the drainage volume information from the unstructured grid system using fmm, and the simulation results are validated with finitedifference based and finitevolume based numerical results. Structured versus unstructured pebi grids in reservoir. Unstructured, controlvolume distributed, fulltensor. Hybrid mesh generation for reservoir flow simulation in. Numerical modeling of fractured shalegas and tightgas. Deutsch to move forward with the use of unstructured grids in modeling reservoirs, geostatistical methods to.
The toolbox is intended for rapid prototyping on complex cornerpoint grids and demonstration of the multiscale simulation. The methods are applicable for any system of conservation laws where the flow density is defined by a gradient law, like darcys law for porousmedia flow. Computational aerothermodynamic simulation issues on unstructured grids peter a. Petroleum reservoir simulation using super element method. Discretization on unstructured grids for inhomogeneous, anisotropic media.
In this paper, new developments for grid generation, upscaling and streamline simulation for such models are described. By doing such thing, the cells of the reservoir are modi. The first application of unstructured grids in the petroleum reservoir area. Though this concept was introduced to the petroleum industry as. Modern reservoir simulation faces increasingly complex physical models and highly resolved, unstructured grids. Next we describe the techniques used for grid generation both in. Significant work has been done for generating unstructured grids. Upscaled unstructured computational grids for efficient. Application of fluxcorrected transport to an unstructured. Application of the unstructured grids in the numerical simulation of fractured horizontal wells in ultralow permeability gas reservoirs.
New modeling approaches based on hierarchical functional form representation and novel. Modeling scalar variables on unstructured grids john g. Use next generation simulators that honors geology with unstructured grids. A tvd scheme for 3d unstructured grids applied to compositional reservoir simulation article pdf available in brazilian journal of chemical engineering 344. Unstructured gridding has become an important subject matter in reservoir simulation.
Embodiments of the present invention utilize a geochron model for construction of the simulation grids. Symmetric positive definite fluxcontinuous fulltensor finitevolume schemes on unstructured cellcentered triangular grids. Deutsch an outstanding issue in geostatistics research is the extension of modeling algorithms to unstructured grids, which are being used for reservoir flow analysis. However, for more complex flows, the adaptivity facilitated by an unstructured grid may allow more accurate solutions. Although the use of unstructured grids for fluid flow simulation in complex geometries is currently a customary practice in several engineering areas, still little effort has been made in the. Structured versus unstructured pebi grids in reservoir modeling and simulation bogdan balan, schlumberger gss abstract application of unstructuredirregular grids in reservoir simulation is one of the most important concepts that have been developed in the past decade 1. Computational aerothermodynamic simulation issues on. Globally structured grids, including the socalled stratigraphic or cpg corner point. Discretization on unstructured grids for inhomogeneous.
Reservoir evaluation can be broken into two main categories. Pdf unstructured coarse grid generation for reservoir. Gataul linmodeling of hydraulically fractured wells in full field reservoir simulation model 2008 spe 117421. The objective of this project is to develop a reservoir simulator with the capability of simulating various recovery processes under one framework. Rupperts algorithm is often used to convert an irregularly shaped polygon into an unstructured grid of triangles. Introduction one of the main goals of petroleum industry is to maximize oil production from each. The fully implicit solution method has been successfully applied to reservoir simulation with unstructured grids. The problems involved in using a regular structured grid to represent reservoir geometry can be avoided by using an unstructured grid. Currently, there is little consensus regarding the effects of nonideal fracture geometries and coupled primarysecondary fracture interactions on reservoir performance in these unconventional gas reservoirs. The use of unstructured meshed has proven to be a valuable tool for reservoir. Knutandreas lie an introduction to reservoir simulation using matlab user guide for. The first release is geared towards single and twophase flow and contains a set of mimetic and multiscale flow solvers and a few simple transport solvers capable of handling general unstructured grids.
White nasa langley research center, hampton, va 23681 the synthesis of physical models for gas chemistry and turbulence from the structured grid codes laura and vulcan into the unstructured grid code fun3d is described. Currently, this type of grids is being gradually adopted in reservoir simulation, because actual petroleum reservoirs frequently exhibit such complex geometries and intricate geological features that only can be represented accurately with unstructured grids. In combination, these techniques provide a prototype workflow for the construction of unstructured simulation models. Well indices for complex well configurations in unstructured grids. 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. Numerical modeling of fractured shalegas and tightgas reservoirs using unstructured grids. Shalegas reservoir simulation tightgas reservoir simulation.
Transmissibility upscaling on unstructured grids for highly. For reservoir simulation using the blackoil model on unstructured grids, only the fully implicit solution method has been used for solving the governing equations of this. This thesis provides a grid construction tool to generate highresolution unstructured meshes using voronoi grids, which continue reading. The finite volume grid is formed as the dual of the underlying tetrahedral in three dimensions or triangular in two dimensions primal grid. Spe rss aim clees ganzer 20061204 tc clean fraunhofer scai. 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.
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