Characterising Relay Structures in Carbonate Rift Systems and the Implications for Structural and Depositional Reservoir Uncertainty

Summary Segmented fault systems and relay structures are recurrent features in rifts and faulted continental margins that play a critical role in determining flow behaviour associated with fault seal variations and depositional drainage patterns along fault zones ( Fossen & Rotevatn, 2016 ). However, the prevalence and extent to which interpreted faults are segmented beyond conventional imaging and modelling resolutions is typically oversimplified through the interpretation of faults as singular, planar structures often too coarse to represent the constituent segments of the fault zone. We present a workflow that utilises the interrogation and analysis of high-resolution, interpretation-scale displacement profiles that can provide critical insight into the potential extent of fault segmentation, drawing on fundamental principles of fault growth and evolution to identify missed and/or obscured structural architectures that are key to more reliable structural modelling and reservoir characterisation workflows. Examples are presented from carbonate reservoirs of the Santos Basin in the Brazilian southeastern coast, where complexities in large faults that have been impacted by pre-salt seismic imaging challenges are addressed through the reinterpretation of additional fault segments and the application of semi-automated, holistic relay zone and fault segmentation characterization diagnostics.