Fracture Characterizing and Modeling of a Porous Fractured Carbonate Reservoir, SW Iran

Anisotropy and heterogeneity in reservoir properties introduce challenges during the development of hydrocarbon reservoirs in naturally fractured reservoirs. In reservoir simulations, grid-block properties are frequently assigned to obtain reasonable history matches. Even then, accuracy with regard to some aspects of the performance such as water or gas cuts, breakthrough times, and sweep efficiencies may be inadequate. In some cases, this could be caused by the presence of substantial flow through natural fractures. In this work the fracture characterization and modeling was performed in a highly fractured carbonate reservoir in SW Iran. It was observed that reservoir simulation based on the generated fracture model present a more reasonable history matching of the production. The study indicates that NE-SW is the dominant orientation of critically stressed fractures that are most problematic for gas/water breakthrough. The primary objectives of this study are: a) construct a fracture 3D model to be used in reservoir simulation and b) distinguish the most problematic fractures in water/gas breakthrough. The steps of this study are as follows: -Constructing the 3D geological framework of the reservoir. -Identifying and characterizing natural fractures at the well level using borehole images. -Generating the 3D-stochastic model of discrete fracture network (DFN), incorporating image log data with outcrop analogies studies in the context of buckle folding mechanism. -Scaling up the fracture model with integration of well test results -Running reservoir simulation based on the scaled-up fracture model to validate the model and observe the history matching -Performing critically stressed fractures (CSF) analysis to distinguish problematic fractures.