High Resolution Sequence Stratigraphy And Predication Of The Favorable Sand Bodies Of Hanjiang Formation Along The Shelf Slope-Break Zone Of The Southeast Panyu Natural Gas Area

The Pearl River Mouth Basin is northern passive continental margin basin of South China Sea.The region of interest is in the transition zone of east Panyu low uplift and Baiyun depression,which is one of the hot spot exploration region of the Pearl River Mouth.In this paper,guided by the theory of Sequence Stratigraphy,Sedimentology,Geology and Seismic Sedimentology,Seismic Geomorphology and Basin analysis,and based on seismic reflection datas,well loggings and cores,Hanjiang Formation in this area is divided into three third-order sequences,which are bonded by unconformition surface characterized by truncation or onlap contacts and its relevant conformity surface(SQhj1?SQhj2?SQhj3),and each third-order sequence is subdivided into three to four forth-order sequence or system tracts.On a base of seismic reflection datas and well loggings,the lowstand system tract of SQhj2 can be recognizied as early and late periods,and a falling stage system tract is developed in the late highstand system tract of SQhj1.In the chronostratigraphic framework,based on the comprehensive study of cores,well loggings,seismic facies and seismic attribution technique,primary depositional systems and sedimentary facies are described.The sedimentary environments of Hanjiang Formation in this area includes river delta deposition system,shelf edge delta deposition system,offshore and shallow marine continental shelf deposition system,and deep water slope deposition system.It is shows that there is a S-shaped foreset delta in the highstand system tract of SQhj 1,and there are two sets of lowstand system tracts in the third-order sequence of SQhj2,which are composed of incised valley filling-type deposits,lowstand wedge deposits,and lowstand fan deposits.On the basis of the sequence structure and depositional system tract were demonstrated,carry out the study of the basin paleogeomorphology,fracture slope break zone,tectonic subsidence and sea-level change controlling on depositional sequence evolution,reveals the main controlling factors of the depositional sequence formation of the Neogene in this area.On the basis of analysis above,lithologic and stratigraphic traps in several area are forecasted.The incised valley-basin floor fan complex of SQhj2 lowstand system tract and delta sand body in the late highstand system tract of SQhj1 are predicted to provide reference for the petroleum exploration.