Fine Stratigraphical Division And The Study Of Sedimentary Characteristics Of Neogene Strata On The Northern Slope Of Kendong

The practice of geological prospecting has proved that Neogene strata on the northern slop of Kendong is a favorable area containing oil or gas, belonging to fluvial facies. However, the prediction of reservoir on this area is very difficult because that the reservoir has the relatively large horizontal and lateral changes and be thin interbedding. To regard the Neogene strata of kendong34-block, especially the upper member of Guantao formation as the target formation, this paper determines correlation marker according to isochronism, sedimentary facies control laws consistency and depositional cycles consistency and divides the upper member of Guantao formation into six sand groups and 28 sublayers. And according to equal elevation patterns, contrast model of overriding sand bodies and contrast model of facies change, this paper carries out the work of stratigraphic division and correlation against the upper member of Guantao formation of kendong34-block. In the end, this paper establishes stratigraphic framework model of the region and stratigraphic isopach map and top surface structural map of the upper member of Guantao formation of kendong34-block on the basis of above work.This paper makes core observation, particle size analysis, thin section analysis as the main research methods, combines with logging data, paleontological data ,The Sahu judge by the results of formula, rivers wide and deep river curvature than the calculated results and the material research of neighboring block, Determine the fluvial zone, part of the river for the high-curvature, and some for low-curvature; refer to the scholars of the ancient river classification theory, and definitely put forward that the upper member of Guantao formation on the northern slop of Kendong is the anabranched channel facies, rather than meandering river sedimentary considered traditionally.On basis of the establishment of anabranched channel facies model, Of the main sand and small layer of sand body thickness, percentage of study, and further to the main sand and small sub-layer deposition of sand body (micro) phase plane portrait of the fine; Layer on the profile formation and development of small sedimentary microfacies characteristics describedand then summarize the development law and characteristics of different types of sandbodies. Combining with effective thickness analysis, point out the development position of advantageous sandbodies and its distribution law, and bring up an optimizing target for oilfield prospecting and exploiting.Studies suggest that 21, 22, 34, 24, 33 layers of Kendong34-Kendong34A-5 well,Kendong34A-4 well,Kendong34A-1 well block on the southwest high position and 21,23 layers of Kendong34B-1well, Kendong344-Kendong34C-3well, Kendong34C-ZP2- Kendong 342 wellblock in the middle area are the optimizing targets.