T2013-05-UG Multi-scale modelling 1.2 University Cluster

Summary

In this study we perform finite element (FE) geomechanical simulation to quantify mechanical response in terms of loading, failure and growth of complex network of pre-existing Flt-Frc. This can be done to much greater detail by starting from a pre-existing network than by modelling the incipience of a new network. The characteristics of a pre-existing Flt-Frc network is best obtained from deterministic reservoir data combined with outcrop analogue studies. Deterministic fracture-fault (Flt-Frc) network descriptions are used where feasibly, otherwise network characterizations in terms of shape, directions, spacings, heights and lengths are used to describe the discontinuity surfaces.

Building on the results of the 1st stage, this proposal focuses on the volume surrounding the borehole.

We start refining the geological/fracture model, continue investigating the mechanic response to changes in boundary conditions and set the first steps to analyse the impact of fluid injection by investigating the consequences of effective pressure reductions on existing fractures and faults, as well as on the generation of new discontinuities.

This proposal aims at predicting the mechanical response based on discrete surface network models that include intermediate scale (101-103 m) fracture-fault networks. This intermediate scale bridges between the induced small-scale fracturing around boreholes versus the critical loading of faults at the largest length scales for seismic risk.