Lithologic Trap Prediction Of E-s-4Formation In Chunguang Block, Junggar Basin

The research area of Chunguang block belongs to Chepaizi uplift, which islocated in Northwestern margin of Junggar Basin. For recently decades, the study ofJunggar basin and even Chunguang block was major in deep layer of Permian、Jurassic and shallow layer of Shanwan Formation, the study for Paleogene have nobreakthrough development. Therefore this article predicts advantageous lithologictraps through the depositional system research of E-s-4Formation.This article is guided in the Standardization of sequence stratigraphy ofO.Catuneanu, comprehensive use of all kinds of information, use the T-R patternunder the monitor of the single well set up sequence stratigraphic framework to markoff sequence and different system tract. Based on the existing framework, combinedwith wave analysis, velocity analysis of well and analysis of seismic phase to identifysand, through the sand body scanning methods explain the sand for research area,analysed characteristics of single sand body and the composite sand body from plane,utilized seismic facies and lithic facies to divide sedimentary facies belt, and byfurther combination with depositional context to accomplish the analysis of watersystem and depositional system. Finally, based on the research of sedimentary systemto evaluate shelter conditions, migration condition and seismic response condition topredict advantageous traps.The major achievement and understanding include:1、Research area of Paleogene based on T-R pattern, which divided into onesequence. And identified transgression and regression, the fourth sand group wasdeposited during the regression.2、Study area mainly develop sand typeⅠand sand typeⅡdevelop partly throughvelocity analysis. Analysis three different wave to understand its distinguish based onthe wave analysis theory, the sand of the fourth sand group mainly develop rightdipping waveform (reflect low-velocity layer of high porosity and permeability)through combine the well and seismic. Therefore, in the negative display profilessection, explaining trough that is tracking of the sand of top interface. Finally, combined with waveform analysis, the relative velocity analysis and seismic faciesconducted the study area interpreted sand body scanning.3、 The sedimentary system of the fourth sand group is braided riverdelta-lacustrine delta. The sand on the plane show foreset of nine times, according tothe direction of foreset, author realizes that flow come from northwest and north. Fiveunderwater distributary channels were developed in research area, which has fourNW-SE branch channels and one N-S branch channel.4、 According to information gathered show that Chunguang block belongs toexternal source reservoir, which has no source rocks, but has good reservoir rock andcap rocks. Therefore, search the advantage migration pathway is the key for formingwell oil and gas reservoir. Adjacent to the source depression major unconformitycompleted lateral migration，and hongche fault belt is the key role in its longitudinalfault migration.5、 By evaluate the fourth sand group lithologic traps conditions，author find out14lithologic traps in E-s-4formation，which five favorable traps are located in thedelta front most favorable for lenses traps.