Oil Enrichment Controlling Factors And Target Area Forecast Of Yan 10 Oil-bearing Formation-Yan 8 Oil-bearing Formation In Yanchi-dingbian Area

Yanchi-Dingbian area is located in the northwest of Ordos basin, it is multiple reservoir oil enrichment area, Yan 10 to Yan8 oil-bearing formation is one of the main productive layers of Jurassic reservoir, and paleogeomorphic background is base for the formation of Jurassic reservoir in geomorphology sequence. Through constructing, geomorphology, sedimentary microfacies and reservoir evaluation methods to study comprehensively. It can reveal the hydrocarbon accumulation rule better, and predict favorable reservoir distribution blocks. In this paper, using the method of "impression"- Yanchi-Dingbian area of Ordos basin to recover paleo geomorphology form before the Jurassic,, then analyzed the ancient river reservoir distribution characteristics with the existing oil and gas exploration distribution characteristics, controlling factors, and summarizes its model. On this basis, make the favorable area for prediction and evaluationYanchi-Dingbian area district before the division of the Jurassic paleogeomorphology unit includes erosion valley, slope belt and mound, three ancient geomorphic units, the characteristics of Yan10 to Yan 8 top surface structure is southern sag, northern high and the top layer structural surface development some low amplitude, extending slightly short north-south like nose structure. Based on the development in the detailed characterization of slope belt of three or four ancient river, people can find that the ancient river reservoir mainly found two mounds in the slope mouth secondary river source and three or four level interchange on the formation of the ancient river. Through the analysis the characteristics of different layers and different wells reservoir, that Yanchi-Dingbian area on the basis of pre Jurassic palaeogeomorphology derivative and formed by differential compaction small amplitude anticline(nose) is formation of Jurassic reservoir in the main factors can be summarized as follows geological-geomorphological setting, structure, lithology, the top of the sand body, the secondary venturi nozzle.