Modelling Sub-seismic Fault Patterns using a Marked Point Process

Abstract

A method for integrating sub-seismic scale faults as part of a more complete reservoir description is presented. The faults are represented by single planes and displacement of adjacent strata. An established stochastic model for the sub-seismic scale faults, with a simulation algorithm, has been developed further. The model allows for the inclusion of seismically visible faults. They thereby influence the overall fault probability distribution since the model includes interaction between the faults. The interaction includes both repulsion and clustering. This produces fault patterns which are considerably more realistic than those published previously. An example of such a fault pattern realization is provided. Two ways of introducing the effect on fluid flow are used. One method modifies the fine-scale permeability field. A new homnogenizaion procedure has been implemented to interface with the fluid flow simulator. The other introduces the faults on the borders in the fluid flow block system. The second and simpler method is adequate when the simulated faults are fairly large compared to the flow simulation blocks, while the first method should be used when large numbers of small faults are simulated.