| This paper mainly studies the 4th to the 2nd member in the Shahejie formation of Chengnan fault zone in Bonan sag. Based on the theories of sequence stratigraphy and sedimentary analysis, the sequence stratigraphic framework is set up, Sedimentary System of the 4th to the 2nd member in the Shahejie Formation are analyzed. In the same time, using the results about previous studying, controlling of structure features on sedimentary system is studied and controlling modeling on sedimentary of different sections of the Chengnan fault is set up. Based on the analysis of reservoir characteristics, prospective sedimentary zone is divided and prospective targets are further predicted for the further exploration in the 4th to the 2nd member in the Shahejie Formation.This paper altogether includes five chapters:The purposes and significances of the thesis are discussed in the first chapter. In this chapter, the present states and perspectives of sequence stratigraphy and sedimentary, and the exploration and research status of Chengnan fault zone in Bonan Sag. are introduced. Based on t analysis of drilling, logging and seismic information, the sequence stratigraphic framework is set up and sedimentary system is studied, the mode on sedimentary is built, prospective sedimentary zone is further divided, conglomerate bodies are fine depicted, and prospective targets are predicted. It is studied through researching tectonic- sequence--sedimentary system together.The second chapter describes the regional geological features of Bonan sag. Bonan sag located in Jiyang depression of the Bohaiwan Basin, the northern part of Zhanhua sag, Chengnan fault zone is a steep slope zone in the north of Bonan sag, the overall trend for the northwestward west toward, bounded by the Chengnan fault in the Bohaiwan Basin, directed to the northeast is Chengning uplift and southwest is Jiyang depression. Bonan depression experienced three stages of development during the Paleogene, including the initial rifting episode, rifting stretching episode and convergence episode. The period of Sha-4 is the late of the initial rifting episode, basin margin fault activity gradually increased, slope becomes sharp; The period of Sha-3 is the rifting stretching episode, the range of lake is widest, the deposition in the area of Chengnan fault zone is stability, little sediment thickness and shortage supply of elastic material; The period of Sha-2 is the convergence episode, Bonan sag uplift during this period, the lake level back toward to the sag center and thinner of the sediment thickness.Sequence stratigraphic framework of the 4th to the 2nd member in the Shahejie Formation of Chengnan fault zone in Bonan sag is established in the third chapter. Based on the three-dimensional seismic data and tectonic setting information of Bonan sag, the seismic reflection characteristics of each sequence in the region is recognized. Based on the previous sequence stratigraphic classification, typical identification mark of seismic sequence boundary, and the baseline sudden change of borehole log, and by fine calibration of layers, sequence stratigraphic framework of the 4th to the 2nd member in the Shahejie Formation is established. Three sequences are identified:SQEs4,SQEs3,SQEs2. Two charts such as, structure buried depth of the bottom boundary and residual strata dispatch map of the 4th to the 2nd member in the Shahejie Formation, are plotted on the base of detailed interpretation of sequence boundaries in three-dimensional work area. And its distribution characteristics are analyzed.The fourth chapter puts focus on the sedimentary system analysis. It is three types of sedimentary systems:gravity current, lake, and fan-delta that can be mainly distinguished in the stage of the 4th to the 2nd member in the Shahejie Formation based on the results of previous studies and present works, which is integrated all kinds of information, such as observation of cores, interpretation of three-dimensional seismic, drilling lithology logging curve, sedimentary facies of cores, sedimentary facies of single well, extraction of typical seismic facies and seismic attribute. The sedimentary facies are controlled by many factors, such as sediment supply, the strength of fault activity, and the size of the accommodation space occurs by slope-break zone and subsidence rate., in all of which the strength of fault activity is a dominated factor. The composite patterns of Chengnan fault system is analyzed, the controlling role of the activity of Chengnan fault system is discussed, the sedimentary mode is summarized, and it includes fan-delta facies near mountains and fan-delta facies near alluvial fan. Fan-delta facies near alluvial fan are developed on the southeast of Chengnan fault, controlled by gentle slope at down throw block. Then, the fan-delta facies near mountains are developed on the northwest of Chengnan fault, is controlled by steeper slope in the basin marginThe fifth chapter basically prospective targets are predicted, and favorable facies zone is divided based on the research of sedimentary system and the characteristics of reservoir of research area, the glutenite of Research area mainly growth in the fan-delta plain and phase position and also growth in all the bed series with good petrophysical properties. Especially the transfer zones in the central of the Chengnan fault are the most favorable reservoir formation. Wildly, growth Secondary fault in the area and oil source communications are good. Finding the typical representative of conglomerate bodies, analyzing the conglomerate bodies spatial distributing of different period. Summarizing advantage trap types, including structural trap, litho logic trap, stratigraphic traps and composite trap types.Thus, subtly depicts the favorable traps from the 4th to the 2nd member in the Shahejie Formation, studies the spatial distributing, analyzes the internal structure features and the control factors, Combined with accumulation conditions, favorable target bodies are predicted.
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