Hydrocarbon Plumbing System in the South Falkland Basin

Analysis of a 2D seismic dataset from the South Falkland Basin reveals a large number of different amplitude anomalies and fluid flow structures in the Mesozoic and Cenozoic fine-grained successions. These amplitude anomalies are associated with 1) bottom simulating reflection (BSR), 2) enhanced reflections (ERs), 3) pipes, 4) disturbed signal zones (DSZs) and 5) flat-spots. The prominent BSR extend within the central part of the South Falkland Basin and is associated with gas hydrate stability zone (GHSZ). The ERs are interpreted to be gas charged layers and associated with a free gas zone. The pipes are observed as columnar regions of vertical disturbance and they are located above structural highs. The DSZs are located in the deeper portion of the basin and are characterised by stacked amplitude anomalies. These DSZs are located above structural highs. Some flat-spots have been identified and analysed. These flat-spots are consistent with AVO class III response. The hydrocarbon potential of the basin has been recently confirmed by an important gas condensate discovery (Darwin). This discovery suggests that the observed anomalies and fluid flow structures, in association with their acoustic responses, are direct hydrocarbon indicators (DHIs) and potentially linked to a hydrocarbon plumbing system.