The north slope of Baiyun Sag is one of the important areas for the oil-gas exploration in Pearl River Mouth Basin. Based on cores,seismic,log and paleontological data,14 third-order sequences were identified in the Neogene of the study area by the former researcher. Under an isochronous stratigraphic framework,this paper analyzed the sequence architecture of key sequences on the north slope of Baiyun sag,and predicted the play fairways. From north to south,4 types of sequences,including H type,TH type,T type and L type,were developed successively. Among them,the H type and L type were favorable for reservoir development,while T type was favorable for development of source rocks. Moreover,the joint control of multiple geologic conditions led to the development of various types of delta in the Neogene on the north slope of Baiyun sag. Alternating shelf-margin delta,inner-shelf delta and mid-shelf delta may occur successively in a single sequence. The L type sequence is mainly composed of shelf-margin delta,canyon channel and turbidite fans;the T and TH type sequences are dominated by inner-mid shelf delta and shelf system;and the H type sequence consists minaly of mid-shelf delta and shelf system. As a result,distributary channel sandbodies in the inner- or mid-shelf delta in the northern part of Baiyun sag,as well as the underwater distributary channel,river mouth bars,distal bars,canyon channel and turbidite fans were all favorable for oil & gas accumulation in the study area.
