Utilizing core

well logging and 3D seismic data

technologies such as horizon flattening

section and attribute analysis were used to reconstruct the paleogeomorphology environments in Changxing and Feixianguan Formations' main sequence boundaries in Jiange and Jiulongshan districts

the Sichuan Basin.The features of paleogeomorphological evolution were investigated and their control on the reef flat were discussed.Results show that paleo topography of the area is featured by higher southwestern parts and dipping down to the Northeastern parts.The carbonate platform's constant progredation from southwest to northeast during the paleo-geomorphological evolution in the area leds to features such as marine regression

sediment filling into deep water during the periods of Changxing and Feixianguan deposition.The reef flat's favorable depo-center areas were also transferred in tune with the migration of paleo-landform's high belt and platform margin.The area around wells Lg68

Lg63 and Lg62 is an inherited paleogeomorphological high grounds

representing the most favorable place for the reef flat's vertical aggredation of Changxing and Feixianguan carbonates in the Jiange district.The major positive structure in Jiulongshan area is composed of Feixianguan formation's second section

which are a set of platform margin oolitic beaches superimposed one on another in transverse and overlaying fashion.It is also the most favorable area for development of oolitic beach in Feixianguan formation.