SEDIMENTARY SEQUENCE CHARACTERISTICS AND FAVORABLE RESERVOIR FACIES—TRACT PREDICTION FOR THE PENGLAIZHEN FORMATION OF WEST SICHUAN AND ADJACENT AREAS

The Penglaizhen Formation in West Sichuan and adjacent areas is thick over 950-1600m,which was deposited during the wilting period of the Jurassic lake basins.Based on the combined demarcation of sequence interfaces and maximum transgressive interfaces,Ⅲ₃ and Ⅲ₄ two sets of sedimentary sequences are classified.By analyzing on the cycles of sedimentary base levels,the sedimentary facies types and apace-time distributive characteristics of the Penglaizhen Formation are discussed,the favorable facies tracts are predicted,and the favorable hydrocarbon-enriched blocks are classified.