Importantly, we can model the effects of faulting not just simply within fault cores, but also within the damage zones around them. Using throw and juxtaposed stratigraphy, we can derive fault-rock type and damage zone structure, and model their consequent effects on fault plane permeability and transmissibility. Using host and granulation seam permeabilities, and fault and damage zone scaling relationships (derived from our R and D programme), a complete suite of structurally derived permeability relationships can be calculated and mapped by our FaultRes software.

Fault throw plot produced by ABAL's new FaultRes software. Reds indicate areas of highest throw, and dark blues low throw.

Fault seal potential plot produced using FaultRes. The reservoir sands in the footwall are predominantly red (well sealed). The yellow and green areas indicate poor fault seal potential.

The integration of reservoir data at all scales is the key to evaluating and quantifying small scale structure. We use core, image log and petrophysical data, and conventional and seismic attribute data, to define parameters for the stochastic modelling of subseismic structural features, using scale invariant models. Along with major faults, these small scale structures have a demonstrably significant effect on the flow characteristics of the reservoir interval over the entire area of the field. Our FracMod software calculates the effects on permeability of real and modelled structures.

Field scale map showing seismic / coherency interpretation. Faults have been coloured according to level of confidence.

Together with stochastic models of subseismic scale structure derived from core and image log data, the effects of all scales of structure are modelled and their impact on reservoir permeability captured in permeability modifier grids.