The western Sichuan depression has experienced very complicated evolution.As a result

it is characterized by vertically stacking of various basin types

multiple styles of trap strucuture

multiple source and resevoir rocks

and multiple superimpositions and reconstructions.Although abundant petroleum resources have been generated

the special distribution of oil and gas is under-concentrated.Systematic study of dynamics of hydrocarbon reservoiring indicates that there might have been late reservoiring condition in this area

and major migration and accumulation of oil & gas might have occurred before the reservoirs to be tightened.Forming phase of trap is crucial to trap validity

and the features of composite petroleum system control the distribution pattern of gas reservoirs to be three-dimensionally in groups.According to the characteristics of hydrocarbon resources in western Sichuan depression and aiming at the large prospecting targets

main objects of near and medium term exploration plans should be focused on deep gas reservoirs

expanding exploration of moderate deep gas reservoirs and extending the periphery shallow gas reservoirs.