| Reservoir simulation is a useful tool for reservoir management. The presence of fractures makes the domain geometrically complicated, and thus mathematically challenging. The discrete-fracture model uses lines and triangles to represent fractures in two- and three-dimensional spaces, respectively. Compared to the traditional dual-porosity models, it has the advantage of representing fracture orientations explicitly. The discrete-fracture model has been implemented by employing the finite-element discretization. Mass conservation at the local level has always been an issue in solutions of multiphase flow problems using the finite-element method. It has been proven that the control-volume finite-element method is not flux continuous because it uses a potential-based upstream-weighting function. A new, flux-continuous, locally mass-conservative, control-volume method for the solution of multiphase flow problems in porous media is developed in this work. This method is shown to be flux continuous because it uses a flux-based upstream-weighting function. Numerical examples show that the proposed control-volume method has significantly less grid-orientation effect than the control-volume finite-element method.; It is traditional in reservoir engineering to use the indexing method to verify a new simulator. The convergence properties of the new simulator cannot be verified because the errors in the existing simulator are not known. The method of manufactured solutions overcomes this problem and is introduced in this work to reservoir simulation for the first time. Convergence behavior of numerical algorithms can be studied using this method. The pressure and saturation solutions are verified to be first-order convergent as expected.; Superposition of discrete-fractures has been made possible in this control-volume finite-element research context. This implementation shows, physically, that fractures are conduits that enhance flux between existing control volumes. Application to a fractured North Sea reservoir is presented herein. Results show that the control-volume method with the discrete-fracture model can be used to predict production performance for fractured reservoirs.; In a research environment, where improvements are made sequentially, the complexity of the simulator grows as it is developed. Consequently, the design of the development framework is important. The object-oriented design is suitable for simulator development. A modular framework, which separates the parallel implementation from reservoir models, is developed. |
