Geological Controls on Evolution of Submarine Channels in Song Hong Basin, Offshore Vietnam

Abstract

Song Hong basin is a very large basin with complicated onshore to offshore geological structure. The basin comprises the pre-Tertiary basement and Kainozoi sequences. This study focused on the evolution of submarine channel in Miocene sequence. The study interval is the major reservoir of the basin characterized as submarine channel complex and lower to Middle Miocene carbonates with the porosity of 15 – 25%. The channel is highly eroded into the substrate with c. 7 km wide and 20 km long, trending northwest-southeast. They are ‘U’ to ‘V’ shape, sub-parallel to deep faults which reactivated in the Early and Mid-Late Miocene. The channel deposit is characterized by cut and fill architecture and can be seen as high amplitude, bi-directional downlap. The channels are likely to be controlled by the two inverted phases in Late Oligocene and Middle-Late Miocene. The tectonic events are not only controls the flow directions but also modified the shape of the channels. The occurrence of well-developed submarine channel give a great hydrocarbon potential for the Song Hong basin.