Chapter Four - Basic EDFM approach using Cartesian grid

Abstract

Abstract This chapter will focus on the basics of the embedded discrete fracture model (EDFM) and its application in Cartesian grids. The EDFM is an efficient method used to model fractures with complex geometries in reservoir simulators. Through the introduction of non-neighboring connections (NNCs), it can be conveniently applied to traditional reservoir simulators. This allows fractures with complex geometries, such as fracture networks and nonplanar hydraulic fractures, to be properly modeled. We demonstrate the accuracy of this approach by performing a series of case studies using two commercial reservoir simulators and comparing the results with local grid refinement models and a semi-analytical solution. The limitations of the model are also discussed. In addition, the results show the computational efficiency of the model as the complexity of the fractures increases. We also present two numerical case studies to demonstrate the applicability of the model in naturally fractured reservoirs. The non-intrusive application of the EDFM allows the insertion of the discrete fractures into the computational domain while keeping the original matrix gridding. It also allows the use of the simulator’s original functionalities without having access to the simulator source code. Because of these features, it can be easily integrated into existing workflows for sensitivity analysis, history matching, and production forecasting of fractured reservoirs.