The shifting of exploration target from structural traps to structural-lithologic traps(represented by dolomite reservoirs reef flat facies in Changxing-Feixianguan Formation of)led to the discovery of Puguang gas field-China's largest marine gas field so far.Based on 40 years of exploration achievements

the reef flat sedimentary model

'ternary reservoir controlling mechanism'concerning the deep carbonate reservoirs

and the 'compound reservoir controlling'model

are established by integrating the geological with seismic data.Breakthroughs are also made in the exploration of oolitic beach limestone in the third and fourth members of Feixianguan Formation and dolomite in the second member of Jialinjiang Formation in the periphery structures.Meanwhile

a theoretical system of gas pooling in deep marine carbonates is constructed

and a series of technologies aiming at integrated reservoir prediction are developed.New exploration achievements reveal that there are several potential exploration targets in the area and that Sichuan basin is an important area for future gas exploration.