Southeast Panyu Gas Region Sequence Stratigraphy And Sedimentary Characteristics Of Zhujiang Formation 21-23.8Ma Strata

Pearl River Mouth Basin is the most important area for oil and gas exploration in the north of South China Sea.The study area lies in the center of the basin,including Panyu Uplift,Baiyun Depression and part of Liwan Depression.This article mainly applies sequence stratigraphy and seismic sedimentology to establish sequence straitigraphic framework for 21-23.8Ma strata with geophisics and log technology.And then make systems tract division and portray the sedimentary units and facies in detail in the sequence straitigraphic framework.The study area is very vast with relatively scarce number of drilling well,so the drilling data must be analyzed carefully.According well logs and features of petrology and paleonlology,we can define the sequence boundaries,and the make up several typical well sections.On this basis,combine well analysis and geophisical feature of seismic section,at last,a sequence stratium framework in the whole area is expected to be established.With the research of sedimentary microfacies and the distribution of sand body,The temporal and spatial evolution is studied and described through the established chronostratigraphic framework.Then analysis of singal well,well sections and seismic attribute is applied in seismic sequence framework,so that the development and distribution of sedimentary system can be depicted.Simultaneously,analyze the control effect that is brought about by provenance,slope break belt and synsedimentary fault.Sqzj1 strata were developed in the depression period of the basin and structures and evolutions of sedimentary sequences were mainly controlled by the palaeostructure of the basin,the movement of synsedimentary faulting and the changes of sea level.The delta and braided river delta deposit develop through the objective strata(21-23.8Ma)in studied area.The sand body comes from sedimentary of mouth bar in delta front and distributary channel deposit,which has very good physical properties for reservoir of oil and gas.As a result,this part of the studied area can be seen as favorable reservoir of oil and gas zone.The potential traps in this area comprise the principal units of reservoirs,and the traps can be devided into two types including sand body updip traps and stratigraphic unconformity traps,all of which turns up in the strata Sqzj1 of high sea level section.