Application of Hybrid DPDP-DFN Modeling of Fractured Carbonate Reservoirs

Predicting naturally fractured carbonate reservoir behavior is associated with fluid flow modeling of two and more mediums. Presence of highly conductive faults and fractures complicates the process. These complications are generally addressed by common approaches using DPDP models and modern techniques of explicit discrete fracture networks (DFN) modeling. Dual porosity-dual permeability (DPDP) models do not provide proper results without significant modifications and improvements. Flow simulation of the whole fracture set in discrete format on full-scale models is computationally intensive and time-consuming task thus not applicable for practical purposes. Alternative hybrid modeling approach based on combination of individual DFN objects (faults and long fractures) with traditional DPDP modeling was created based on detailed geological static model. Full scope of available geological, geophysical and production data was used to provide background for flow simulations. Numeric algorithms were optimized for three mediums including single porosity medium (SPM), fracture medium (DFN) and discrete objects representing irregular fault and long fracture systems. Generalized workflows for creating static model, defining fractured zones and explicit discrete objects, followed by DPDP-DFN hybrid modeling are described in this paper. The proposed approach was utilized to perform full-scale model history matching, optimize well locations, estimate risks and uncertainties of gas injection efficiency.