f The Three-Dimensional Architecture of Small-Scale Faults in Unconsolidated Sediments

Prediction of fluid flow in hydrocarbon reservoirs is complicated by the presence of faults, which may act as barriers to fluid flow, as conduits for flow, or be partially transmissive. Seismically resolvable faults can be mapped and incorporated explicitly into reservoir evaluation studies, but understanding the influence of sub-seismic faults, which may be important over production timescales, is more problematic. Understanding the development and geometry of small-scale faults in addition to their microstructures and internal fault zone architecture is therefore vital for optimizing fluid flow models. Faults in unconsolidated sediments described here provide a unique opportunity to study both fault zone structure in relation to fault offset and the geometrical interactions between faults