Sedimentary Microfacies Study Of Triassic Yanchang Formation Chang6₃ In Huangling Area

In this paper, the Chang6₃ of Triassic Yanchang oil formation in Huangling area of Ordos Basin is the research object layer. On the basis of previous research work, by using the basic theory and methods of sedimentology, combining with regional tectonic setting and sedimentary evolution characteristics, to clarify the stratigraphic division of the target strata in this study and then to do material source analysis, phase mark contrastion, judge the type of sedimentary facies, further define the characteristics of sedimentary microfacies developed in the study area.In stratigraphic division and correlation, mainly using the typical stratigraphic division sign of the Yanchang formation, field outcrop data and well logging data to identify and divide Chang6 formation and Chang6₃ formation firstly, and then combined with production actual situation, sedimentary cycle characteristics and thickness principle in study area, do accurate division and correlation of the small layer in the whole study area further more. Finally, the Chang 6₃ oil reservoir is divided into Chang6₃¹, Chang 6₃² and Chang6₃³ three small layers.By analysising the source characteristics of the whole basin, paleocurrent direction, distribution characteristics of feldspar, results of rare earth element analysis, cathode luminescence characteristics of samples in study area, the sediment sources of Huangling area Chang6 mainly come from the north, the rest of the sediment come from the south. The sediment come from the north and south are mixing together.From the study of sedimentary facies sign through core observation and well logging data we can know the Chang 6₃ reservoir of study area in Huangling development deep lake facies sediment. Sand bodies extending generally along north-south trending. The north and south of study area develop the middle fan of the turbidity facies sedimentary subfacies. Sedimentary microfacies are braided channel and channel.