South Malvinas/Falkland Basin: Hydrocarbon migration and petroleum system

- Interpretational framework for frontier petroleum basin is proposed.
- The South Falkland Basin hosts an active hydrocarbon plumbing system.
- The hydrocarbon plumbing system links direct hydrocarbon indicators.

We report a detailed seismic interpretational study of direct hydrocarbon indicators (DHIs) using 2D multichannel seismic reflection data. The study includes analyses of four distinctive types of DHI: (1) a bottom simulating reflection (BSR), (2) enhanced reflections (ERs), (3) pipes and vertical anomaly clusters, which indicate focused migration of hydrocarbon fluids, and (4) flat spots which indicate a deeper source for the shallower hydrocarbon occurrences. The interpretation of these DHIs included analysis of spatial distribution, amplitude variation with offset (AVO) and instantaneous spectral decomposition. These analyses are set in a tectono-stratigraphic context in order to evaluate the relationship between intra-basinal structures, hydrocarbon occurrences and migration pathways. The recent discovery of a gas condensate accumulation in the study area (Darwin well, ca.190MMbbl) confirms the presence of a mature source rock in the basin and supports a model whereby the observed DHIs are connected via an active hydrocarbon plumbing system.