Sequence stratigraphy and prediction of the subtle oil traps in the Dongying Formation in the south-central part of the Liaoxi uplift

The south-central part of the Liaoxi uplift is believed to be the favourable area for the subtle oil traps in the Dongying Formation. The present paper gives a description of the construction of isochronous sequence stratigraphic framework and the distribution of the depositional systems in SQd2 and SQd3 as main target horizons in terms of sequence stratigraphy, provenance analysis and palaeogeomorphology. Other aspects include the controls of sequences and tectonism on the development of the depositional systems in different system tracts, and distribution of favourable reservoir sandstones. Finally, the potential prostects of favourable subtle oil traps are delineated on the basis of the relationship between tectonic features and distribution of the depositional systems in the study area.