Sedimentary and reservoir characteristics of Late Pliocene deep-water depositional units in Rakhine Basin in the Bay of Bengal

Abstract

Significance In recent years, notable discoveries in deep-water oil and gas exploration have emerged in the Rakhine Basin, located in the northern Bay of Bengal. Methods In this study, high-resolution 3D seismic data from the Rakhine Basin were used to identify deep-water sedimentary architectural elements, including channels, levees, lobate fans (such as crevasse-splay lobes and distributary channel-lobe complexes), hemipelagic mud, and mass-transport deposits. Alongside drilling logs and sampling results, the reservoir characteristics and exploration potential of channels, levees, and lobes in the wells were further analyzed, and the reservoir hierarchy and spatial distribution were determined. Results Notably, the Rakhine Basin is characterized by relatively shallow burial depths, weak compaction, and minimal diagnostic alteration since the Pliocene, positioning channels, levees, and lobate fansas potential exploration targets for shallow biogenic gas. In particular, meandering stacked channels emerge as a high-quality reservoir type due to their thick sediment accumulation, strong connectivity, widespread distribution, and elevated high sand content and porosity. Conclusion The research findings can provide important guidance and insights for deep-water oil and gas exploration.

Keywords

• bengal fan
• rakhine basin
• deep-water sedimentary architectural element
• channel
• levee
• lobate fan
• reservoir characteristic