Subsidence
History and Its Impacts to Hydrocarbon Potential of The
Song Hong Basin, Vietnam
Bui, Huyen1, Jack Dvorkin1,
Amos Nur1 (1) Stanford University, Stanford, CA
The Song Hong (Yingehai)
basin, the largest basin in Vietnam can be classified as a
typical pull-apart basin filled with more than 15,000 meters of Tertiary
sediments at its depocentre with predominantly clastics, Miocene carbonate shelf and also some volcanics in Pliocene- Pleistocene strata at the southern
part. Its tectonic evolution and rhomboidal shape is restrained by the
strike-slip displacements of the Red River fault, the spreading of
the South
China Sea
and consequent upon many tectonic phases such as: early rifting, late rifting
and post rifting, forming mainly structural elements. The Song Hong basin has been
considered as high potential of gas. Though many wells were drilled in the
basin resulting in 20 oil and gas shows, there are only two minor gas fields in
production by 2003. In addition to understanding on its hydrocarbon potential,
this research revealed the subsidence history of the Song Hong basin insights from
well log, geochemical data and seismic interpretation. Basin modeling analysis
identified two mainly oil generated phases in the Song Hong basin at about 15
Ma and 5 Ma ago with small amount of oil but very good amount of gas. The
results help to evaluate the source rocks capability, maturation and migration
to the trap of the source rocks, in order to evaluate the hydrocarbon potential
of the Song
Hong
basin.