Loading...

Simulation of Flow in Anisotropic Heterogeneous Oil Reservoirs Using Compositional Model and Cell-Based Unstructured Grid

Moshiri, Mojtaba | 2019

1088 Viewed
  1. Type of Document: Ph.D. Dissertation
  2. Language: Farsi
  3. Document No: 52373 (08)
  4. University: Sharif University of Technology
  5. Department: Mechanical Engineering
  6. Advisor(s): Taghizadeh Manzari, Mehrdad
  7. Abstract:
  8. Reservoir simulation is a useful tool for efficient reservoir management and protective exploitation of non-renewable hydrocarbon resources as the main supplier of development programs in the country. Due to the nature of underground hydrocarbon reservoirs, the simulation faces several challenges, both in rock and fluid parts. These challenges should be overcome in order to provide reliable results from simulations. One of the major challenges pertaining to rock, is large discontinuous variations accompanied by anisotropy of rock permeability fields which causes numerous problems when governing equations are solved numerically. A viable numerical procedure shall account for complex reservoir geometry features which can be accomplished with the use of unstructured girds, and at the same time, the method should be able to fulfil continuity of pressure and velocity especially in case of heterogeneous anisotropic permeability fields. The latter is achieved in this research by utilizing the so-called flux-continuous methods. In these methods, continuity of pressure and fluxes are imposed explicitly on the interfaces of control volumes in computational grid. Moreover, in this study a new method is introduced in which by using consistent averaging of permeability tensor, higher order of accuracy is achieved in highly anisotropic heterogeneous domains. In order to simulate the flow, the governing equations are divided into a pressure equation and a system of mass conservation equations. In each time step, pressure equation is solve implicitly while the conservation equations are solved explicitly. For the first time, the system of mass conservation equations of miscible compressible flow is mathematically investigated and besides the approximation of wave structure, problematic points of numerical schemes identified prior to simulation. Moreover, some numerical schemes for solving conservation equations are introduced to be used in two and three dimensional unstructured grids. Extension of these scheme to high order of accuracy in space and time is achieved in higher dimensions and the results are compared to multi-dimensional upwind scheme. Despite rock complexities, simulation of multi-component multi-phase fluid flow faces a lot of challenges, as well, which are usually overcome by the use of fluid models. In this research, compositional model is utilized which is the best model available to predict the features of multiphase flow. To evaluate the accuracy and computational efficiency of numerical procedures introduced in this research, several numerical test cases are investigated
  9. Keywords:
  10. Numerical Simulation ; Multiphase Flow ; Porous Media ; Compositional Modeling ; Unstructured Grid ; Flux Continous Method

 Digital Object List

 Bookmark

...see more