According to the geologic conditions of Xujiahe Formation in western Sichuan depression to be characterized by super-deep

overpressure

super-tight and super-late structures

systematic analysis of hydrocarbon generation history

pore evolution history and structural evolution history of the known Zhongba

Hexingchang and Pingluoba gas reservoirs and analysis of both positive and negative exploration cases have been made.It has been clear that palaeostructures have acted as the basis of gas accumulation. Yanshanian palaeohigh zone determined the distribution of gas reservoirs

characterized by common early reservoiring

and palaeostructural-diagenetic traps to be the main types of hydrocarbon traps in the study area. Gas reservoirs in Xujiahe Fm in western Sichuan depression have experienced several evolution stages

including conventional trapping in the early stage

suspension in middle period and reconstruction in late stage. Majing-Deyang area

where there is Yanshanian palaeohigh

has experienced similar evolution process

thus it might be a prospective play.