It should be emphasized that the episodic diapirism, as the most important constraint to gas accumulation and evolution in the basin, is in control of trap formation, supplies deep hydr.

Oil field is closely related to fault system and ultrapressure fluid activity in DF1 1 diapir in Yinggehai Basin.

As one of the most important offshore basins in China,there exist many different kinds of fluid diapirs in the Pearl River Mouth basin,which have been introduced in some papers.

The diapiric structures display various types such as a turtleback-like arch, weak piercing, gas-chimney, fault (or crack) and seabed pit, originated in two huge mud-rich strata the Wenchan.

Its particularstructural location and sedimentary environment brought various structural styles,including fault blocks, flowery structure, diapiric structure, inversion structure,buried hills and These geological structures occurred respectively in differentgeological ages and locations, forming superposition structures, so that they creat-ed favourable plac.

The BF is a diapiric structure caused by basement .

The features and types of a new structure fluid diapir structure are discussed in this paper,taking those in Yinggehai and Bohai Bay basins as examples.