Description of the petroleum system(s) of the Song Hong Basin, Vietnam

The basin is in an early stage of exploration with less 20 wells drilled during the early 1990's in a vast area covering some 500 x 100 km. In contrast to other Vietnamese Cenozoic basins located further south, the exploration effort have so far only led to sub-commercial discoveries. The project has primarily been carried out in Hanoi in close cooperation with geoscientists from Vietnam Petroleum Institute (VPI), a subsidiary of the state-owned national oil company Petro Vietnam. A total of some 10,000 line km of digital seismic 2D data, supplied by the Vietnamese partner, covering most parts of the basin have been interpreted using Landmark interactive workstation facilities. Regional and semi-regional time structure and -isochore maps of key markers have been produced. Inter-well correlations between 16 exploration wells were carried by tying a large number of seismic marker horizons to the well-sections in order to establish a consistent chronostratigraphic framework for evaluating the basin development. Existing geochemical data were used to review the source rock potential and new analyses, including hydrous pyrolysis, were carried out on outcrop samples of Paleogene lacustrine carbonaceous mudstones. The latter are from seismic facies evidence believed to represent an analogue to terrestrial oil-prone source rocks offshore. The maturity level and the hydrocarbon generation history relative to trap generation for potential source rock intervals were evaluated basin-wide using the Yükler 1D basin modelling software. Although major parts of the basin are considered gas-prone, the modelling results suggests the presence of an active oil source kitchen in the north-eastern part of the study area