Characteristics of Stratigraphy and sedimentation of the Phu Khanh Basin and adjacent area

Abstract

The Phu Khanh Sedimentary Basin is situated in the deep-water offshore area, east of the continental shelf of Central Vietnam. This area is said to have quite good oil and gas potential, but very few geological and petroleum research projects have been carried out in the past. In this article, the authors update new research results based on new seismic interpretation and well data conducted in recent years. The obtained results show that: Stratigraphy of the Phu Khanh Basin was subdivided into 5 large sequences, including: a. Eocene(?)/Oligocene unit is mainly clastic sediments of fluvial/lacustrine, delta plain and marine environments, b. Lower Miocene stratigraphy: Includes deltaic clastic sediments and shelfal carbonates; c. Middle Miocene stratigraphy: includes delta-plain, shallow marine terrigenous sediments and shelfal carbonate, d. Upper Miocene and Pliocene - Quaternary units include continental shelf and deep-sea terrigenous sediments. Each unit of stratigraphy and corresponding sedimentary environment is related to each stage of the geological and tectonic evolution of the basin. In general, the trend changes from the fluvial/lacustrine environment to the deltaic, shelfal and deep marine environments upward. Establishing the names of the formations and the presence of the Eocene sedimentary rocks in the Phu Khanh Basin is still an open issue. More detailed data, especially well data, are needed to obtain a more convincing interpretation.