Abstract:

Stratigraphic lithofacies assemblages are regularly distributed  within different system tracts of the sequence stratigraphic framework. The present paper deals with the  concept, types, recognition criteria and implications of sequence stratigraphic architecture  in order to effectively  predict  the development of reservoir and the distribution of  hydrocarbon source rocks. Sequence stratigraphic architecture can be defined as the temporal and spacial relationship of the system tracts within the sequence stratigraphic framework. The types of sequence stratigraphic architecture include type L, T, TH and H with subtypes  of EH and LH. Type L sequence is usually characteristic of sand prone lithofacies with excellent reservoir properties; type T sequence is typical of shalerich lithofacies containing excellent hydrocarbon source rock;  both type TH and subtype EH are shalerich lithofacies  but subtype EH  developes less  hydrocarbon source rocks than the type TH, and subtype LH is characteristic of sand prone lithofacies  with relatively developed  reservoirs. As illustrated  by using the sequence stratigraphic architecture of Wenchang Formation in the Huizhou hydrocarbonrich sag, Zhujiangkou Basin,  it is showed that the type T sequence acts as the excellent hydrocarbon source rock in the southern margin of the Huizhou sag, and the  type H sequence is the good reservoir in the northern margin of the Huizhou Sag.

Key words:  sequence stratigraphic architecture, reservoir, hydrocarbon source rock, prediction, Wenchang Formation, Huizhou Sag