Study On Seismic Sedimentology And Itsapplication Of Zhujiang Formation In Wenchang13-1Oilfield

WC13-1oil field is located in the Pearl River Mouth Basin,actually,the Qionghai lowraised central area of Zhu Ⅲ Depression,which is a low amplitude drape anticline developedon the basis of Base uplift.Due to the influence of many factors,such as structural features,sealevel changes,sediment source,the Zhujiang formation developed mainly tidal flat,littoralfacies and shallow marine depositional systems.With the deepening of the oil fielddevelopment,The reservoir geological research scale gets smaller,more emphasis need to beput on the fine description of the reservoir.because of the limited drilling,the research ofsedimentary facies and reservoir discrimination are mainly depend on seismicdata,thus,high-resolution seismic data is required.Developed on the basis of seismicstratigraphy,sequence stratigraphy,sedimentology and geophysics,the seismic sedimentologyjust to meet this requirement,the research scale of seismic sedimentology is smaller thansequence stratigraphy,therefor,more suitable for the research of deposition, reservoirprediction and reservoir heterogeneity during the development stage.The comprehensive utilization of core,drilling/logging data,seismic data,combinedwith regional sedimentary background,this paper clearly illustrate the steps of stratigraphicdivision about Zhujiang formation.On the basis of the analysis of the well data,under thedirection of Sequence stratigraphy theory,make full use of time-frequence analysis andfrequency decomposing technology,divide the Isochronous stratigraphic units into fivesequences,the fifth-order sequences is equivalent to substratum.Using natural gammaparameter of geological statistics inversion forecast sand bodies,recognition interbers,statisticsanalysis sand threshold value,using inversion results forecast sand bodies thickness inisochronous stratigraphic framework.Compared with ZJ1-4U and ZJ1-4M sand group, sand bodies of Z2-1U sand group development larger,flat little difference.Under the constraint oftime horizon,By using various technology,such as Inversion of reservoir,frequency divisioninterpretation technique,Seismic Facies analysis technology,Attribute analysis and strataslicing, according to the geological characteristics of different layers,Selection of efficientmethod,Study sedimentary microfacies,describe the microfacies of tidal channel,rip currentstrench and recesses.Because of the existence of multiple solutions of seismic data,So in thesedimentary facies research in the comprehensive use of various methods, mutualauthentication, to improve the accuracy of sedimentary facies study.Through the fine studiesof sedimentary microfacies,reservoir sand bodies and interlayer effective forecast in theobjective interval,provide a basis for the adjustment of the oilfield development plan nextexploration.