Integrating Fault Throw Uncertainty into Reservoir Modelling - Applications to Exploration and Development Workflows

In exploration and development settings the modelled throw in geocellular grids can have a critical influence on the volumetric fill levels and cross-fault production behaviour, based on the juxtaposition of the flowing units across the fault and the fault seal processes that occur. The exact fault throw is almost impossible to define based on fundamental seismic imaging limitations around fault zones. This uncertainty is typically overlooked during the modelling of fault and horizon interpretations within the geocellular grid. Historically, predicting the effects of modifying the fault throw is a time consuming process, based on the vertical heterogeneity of stratigraphy and the varied response that this may have on the fault properties. We present a method that allows for fault throw uncertainty to be automatically incorporated into both exploration and development evaluation cases. We demonstrate how modifying the fault throw by realistic uncertainty values (i.e. defined from seismic) can grossly under- and over-estimate reserve volumes (by up to 50%) and significantly change the predicted flow behaviour in fault-bound traps. The method we demonstrate allows these uncertainties to be routinely incorporated into exploration and development workflows, allowing for the effects to be captured and included in more concise risk evaluations.