Abstract:

Recent ten years or more,a lot of tilted fault block-buried hill oil/gas traps have been discovered by means of geophysical exploration and drilling in the eastern China Meso-Cenozoic rift-related depression basins,the Viking Gra-ben of North Sea of Europe,the Red Sea Graben of Egypt,Sirte Basin of Libya,Gipslend Basin of Australia and the Baffen-Labrador Basin of Canada.High oil/gas yield was recovered from this new type of traps.They are more likely to develop into good exploration targets both at home and abroad.The mechanism of their occurrence can be explained as follows:1.The crust's tensional stress,resulting from the upswelling of the upper mantle,caused a series of tensional rift-subsidence basins,with heat releasedfrom the upper mantle and creating a rather high geotherm-pressure condi-tions.2.The block-faulting break-up of older platforms or basements formed a series of lineally distributed tilted fault block-buried hill structures.3.The rapid subsiding and infilling environments during the early rifting stage were in favorable conditions for maturation and transformation of sourcematerials.Second crop might occur again from the preserved disconformable ol-der source rocks during the later depression stage.4.Suffering from weathering and karstication for a long geological time,the uplift parts of the tilted fault blocks are often good for reservoir forma-tion.5.Combinations of multiple style of traps and multiple source-reservoir-cap assemblages of the rift-subsidence tensional basins could result in multiple-pay pools.