IMAGE-D6.03: Interacting processes

This deliverable reports the IMAGE results with respect to the above goals for basement/sedimentary reservoirs, with a particular focus towards fractured systems.

This deliverable extends on D6.01 which provides an outline of reference physics-based models, and underlying properties, compositional reference models, boundary conditions and observational data constraints at EU scale for thermal and mechanical characterization. At the EU scale (but also more local scales) we use a lithological interpretation approach to drive properties. This means we derive first in a layered geometry the lithological composition (or lithofacies) and from there derive the relevant properties for that particular lithology based on databases and catalogues which hold in general for that particular lithology. For this reason we defined in D6.01 jointly with the modelling approach, in what way a lithological interpretation can be translated to relevant properties that characterize a geometrically well-defined model unit.

Evidently the multi-physics approach at EU scale, is – in principle – not different from simulating processes active at regional to site scale. There are three challenges which relate to site application:

 Local model refinement is generally targeted at improving robustness through more detail in the modelled processes as well as better constraints in model parameters and properties. Conceptual advancement in linkage of processes and properties or novel solution techniques are key to delivering more detail;

 Furthermore, a major challenge is to optimally use direct measurements of physical properties from different scales, which may exist from within the area of interest or outside it. In this case, it is advisable to use this direct information together with sophisticated (multiscale physical and empirical) laws to populate accordingly the local model;

 Finally the proposed methods require validation in site studies and have practical value for industry workflows.

This deliverable addresses the above challenges with a particular focus towards predicting stress, interrelationship between stress and faults/fractures, permeability and fractures and asscoiated thermal anomalies. In chapter 2 we present approaches to perform multiscale stress models capable to achieve both targets in increased stress resolution constrained by local data as well as capability to constrain the models with regional and large scale tectonic boundary conditions. In chapter 3 we present a novel method to predict complex stress/fault interactions caused by tectonic faulting and fault rheology, as a function of full 3D structural complexity of sedimentary basins. Chapter 4 is focussed towards conceptual understanding of the relationship between scaling laws occurring in natural fracture networks and stress heterogeneities with practical implication for characterising attributes of the fracture network based on well log data sets. Subsequently, chapter 5 presents methods to assess bulk permeability tensor from different approaches in fracture characterization, which can be easily adopted in industrial workflows. Chapter 6 assesses the interrelationship of 3D reservoir fracture permeability distributions and its potential effect on the occurrence of thermal anomalies. Finally, chapter 7 gives a synthesis of the results and provides recommendations for use in industrial workflows.