Optimization of locations of voronoi grid points in reservoir simulation

Rza Guliyev, Ulvi
Reservoir simulations are computer models that can imitate real world reservoir behavior under different circumstances, therefore making it possible for reservoir engineers to make sensitivity studies in order to assess different scenarios. These models discretize the reservoir into smaller blocks either using structured grids or unstructured grids. The application of regular structured grids to correctly map reservoir's geological structure can be very difficult, if not nearly impossible. Unstructured grids can be more convenient for those cases. Voronoi gridding technique creates unstructured grids such that the boundary of two grids is normal to the line connecting Voronoi particles that represents the grids. So that it would be convenient to calculate the transmissibility on the block boundaries. In this study instead of placing the Voronoi particles randomly, or in a regular fashion, the properties of the reservoir such as permeability anisotropy, orientation of the permeability vectors, heterogeneity of the petrophysical properties, and well locations and types were taken into consideration in the placement of Voronoi particles. A three-step algorithm, created in this thesis and written using Matlab software, takes into account the high resolution petrophysical properties in a finer static mesh, together with permeability anisotropy ratio and orientation and well location. This algorithm generates initial distribution of grid points that honors permeability anisotropy, then assigns each grid point an error value, which is dependent on grid point placement, and tries to minimize this error by moving bad points onto better locations. The error gets lower as the Voronoi grids and the background finer static mesh agrees with each other. Finally, after each grid point's location is chosen grid points related to vertical and horizontal wells and fault are added. Algorithm was implemented on six cases of different complexity and then generated Voronoi grid blocks were used in a simple, single phase simulator to show the effects of the optimized grids. It was seen that the developed code during the study can match the given input static model and can reduce the number of grid blocks required to model a hydrocarbon reservoir.


Use of equivalent single porosity medium and automated lumped fluid composition simulation in naturally fractured gas condensate reservoirs
Ertürk, Mehmet Cihan; Sınayuç, Çağlar; Department of Petroleum and Natural Gas Engineering (2018)
Each naturally fractured gas condensate reservoir is unique and needs special interests for an accurate modelling study. Ordinarily, it is a very difficult task to conduct a fast and well-characterized simulation study and predict the performance of such reservoirs in view of the complicated thermodynamic behavior, the complex fluid composition, dual porosity behavior and significant computational time requirement. The numerical simulation of fractured gas condensate reservoirs offer remarkable potential fo...
Modeling of underground gas storage in a depleted gas field
Gumrah, F; Izgec, O; Gokcesu, U; Bağcı, Ali Suat (Informa UK Limited, 2005-07-15)
It is possible to predict the behavior of fluids in permeable and porous medium under different operating conditions by using reservoir models. Since geological data and reservoir properties can be defined most accurately by reservoir models, it has been accepted as a reliable prediction tool among reservoir engineers. In this study, a gas reservoir has been modeled with IMEX Module of CMG Reservoir Simulator. Rock properties, gas composition and certain production data were entered to the model as input da...
Experimental research on in-tube condensation under steady-state and transient conditions
Tanrikut, A; Yesin, O (2005-01-01)
In this research study, in-tube condensation in the presence of air was investigated experimentally at a heat exchanger of countercurrent type for different operating conditions. The test matrix for the steady-state condition covers the range of pressures P = 1.8 to 5.5 bars, vapor Reynolds numbers Re, = 45 000 to 94 000, and inlet air mass fraction values Xi = 0 to 52%. The effect of air manifests itself by a reduction in the local heat flux and the local heat transfer coefficient. The local heat transfer ...
Numerical simulation of groundwater contamination
Ger, M; Baran, Özgür Uğraş; Irfanoglu, B (2000-06-14)
In this study, the finite difference modeling technique is used to develop a simulation program that can be used for groundwater contamination problems. The simulation program is written in C++ programming language and runs on personal computers using Windows 95. The simulation program supplies an interactive user interface containing useful tools for pre-processing and postprocessing the data. Numerical models are capable of simulating two-dimensional areal aquifer systems with various conditions. Finite d...
Simulation of inelastic cyclic buckling behavior of steel box sections
Dicleli, Murat (Elsevier BV, 2007-4)
In this study, a nonlinear structural model is developed to simulate the cyclic axial force-deformation behavior of steel braces including their buckling behavior using the commercially available nonlinear finite element based software ADINA. The nonlinear cyclic axial force-deformation simulation is done for braces with box sections. However, the structural model and simulation techniques described in this study may be applicable to braces with various section types using other commercially available struc...
Citation Formats
U. Rza Guliyev, “Optimization of locations of voronoi grid points in reservoir simulation,” M.S. - Master of Science, Middle East Technical University, 2015.