Determination of geometric parameters of fracture networks using 1D data

To simulate a suitable fracture network for hydrogeological modelling, input statistical data of the individual faults, as well as fracture sets, should be determined first using either 2D sections or 1D scanlines. Although the accuracy of this measurement is fundamental, exact determination is rather problematic and is usually possible only at a particular scale. This paper introduces a coupled method for computing length exponent (E) and spatial density (Dc), the two most essential parameters for modelling fracture networks. To calculate the length exponent, data sets of at least two independent imaging processes are needed. Utilizing different sensitivity thresholds of the two methods and the well-known analytical form of a fracture length distribution function, its parameters can be calculated. To estimate the spatial density of fracture centres in 3D, the series of intersections should be analysed as a fractional Brownian motion and then calibrated with virtual wells simulated with optional modelling software. The method makes fracture intensity logging possible along scanlines. Based on these approaches, there is no need to import fracture parameters from the outcrop survey or from other parts of the reservoir, because all geometric information of the fracture system refers to the rock body under examination. Using site-specific parameters makes fracture network modelling more reliable.