Simulation of Heterogeneous Geomechanical Damage in Tight Reservoir Based on Projection-Based Embedded Discrete Fractured Mode l

Abstract

Abstract An advanced numerical simulation method was developed to accurately characterize the heterogeneous geomechanical damage of heterogeneous matrix, hydraulic fractures, and natural fractures during production. The proposed model can automatically obtain the geomechanical damage correction coefficient according to the physical property differences of the reservoir, which reveals the heterogeneous geomechanical damage law of the spatial domain and the time domain so that the simulation results are more realistic. The heterogeneous geomechanical damage laws of multi-scale fractures are obtained. Due to the uneven pressure drop during the production process, each fracture is subjected to different geomechanical damage, and the permeability drops are not uniform. Particularly, we set the physical properties of each fracture differently in the model, which fully reflects the heterogeneity of the actual reservoir. Therefore, the geomechanical damage law of each fracture is different. The K/K0 distribution of each fracture can be seen in the simulation results. At the same time, the porosity and permeability are coupled based on the classification theory. Therefore, the whole model is dynamic. In unconventional reservoirs, the physical properties of the matrix are poor and the heterogeneous geomechanical damage has little effect on productivity. However, if natural fractures or hydraulic fracturing are developed, the heterogeneous geomechanical damage will have a significant impact on productivity, particularly during early production stages. If the natural fractures and hydraulic fractures are connected, productivity will be more affected. The novelty of the new numerical models that it can characterize the heterogeneity of heterogeneous matrix, natural fractures, and hydraulic fractures in both the time domain and the spatial domain.