Developing a 3D stochastic discrete fracture network model for hydraulic analyses

Abstract

Fluid flow in jointed rock mass with impermeable matrix is often controlled by joint properties, including aperture, orientation, spacing, persistence and etc. On the other hand, since the rock mass is made of heterogeneous and anisotropic natural materials, geometric properties of joints may have dispersed values. One of the most powerful methods for simulation of stochastic nature of geometric characteristics of joins is three dimensional stochastic discrete fracture network (DFN) modelling. The current research is conducted to develop an applicable discrete fracture network model for hydraulic analyses. Also, DFN-FRAC3D software – which was proposed earlier for mechanical analysis - is developed to construct a hydraulic DFN. For this purpose, joint aperture parameter is added to other geometric features of model including orientation, spacing, persistence and intensity. In order to develop an accurate hydraulic DFN model, correlation between the joint aperture and length is also considered, that has not been observed in most previous studies. In this study, the software is developed for detection of connected joint networks. In order to test the performance of the provided simulator, a 3D hydraulic model for fracture network of rock mass in Mazino region is presented.