SKB Apsö UFM application - Case Study

Itasca`s Role

The UFM modelling framework (detailed in Davy et al., (2010, 2013)) is used to assess fracturing parameters and improve the DFN models in Äspö using in‐depth data.

In practice a given set of DFN model parameters is initially related to the spatial volume position and relative dataset from which it is derived. We use both borehole logs and trace mappings along the Äspö tunnel (Figure1).

The UFM relevancy is assessed through the analyses of fracture densities, trace size distributions (Figure 2) and T terminations statistics.

Project Results

We predict a transition scale between a sparse regime (where fractures do not interact) and a dense regime (where fracture organization is governed by fracture‐to‐fracture interactions) between 5 and 10 m.