The paleo-oil pools concentrate on the 4th member of Dengying Formation (Deng 4 member) in Hujiaba section in the piedmont of Micangshan Mountain at the northeastern margin of Sichuan Basin

and their abundance ever increases towards the top

with reservoir asphalt dominated by reservoir asphalt and migration asphalt.The oil-source correlation analysis shows that the hydrocarbons in the paleo-oil pools of Dengying Formation in Hujiaba section are mainly sourced from high-quality source rocks in the Qiongzhusi Formation

perhaps together with source rocks in Deng 3 member.The source rocks in the Qiongzhusi Formation

Northeastern Sichuan Basin entered the early oil-generation stage in the Late Silurian and reached the oil-generation peak at the end of Permian.At this time

the hydrocarbons migrated laterally to the reservoir of Dengying Formation

forming paleo-oil pools.During the Middle Triassic

the organic matter entered the stage of high maturity

with the crude oil in the paleo-oil pools being cracked into gas.Since the Late Cretaceous

the tectonic uplifting and denudation have destroyed these paleo-oil pools

leaving the residual paleo-oil pools at present.The discovery of the paleo-oil pools in the study area is of great significance to the hydrocarbon exploration of the Sinian Dengying Formation in Sichuan Basin.The Deng 4 member is composed of mound-shoal deposits formed at the platform margins

developing high-quality reservoirs dominated by TypesⅠandⅡ; while its overlying Qiongzhusi Formation serves as regional and direct caprocks

featuring good sealing capacity.The favorable reservoir-seal combination indicates that high exploration potential exists in the Sinian Dengying Formation

Northeastern Sichuan Basin.