| In this paper, the application of high resolution sequence stratigraphy of the sedimentary facies and microfacies characteristics, log facies pattern is established, combined with the oil and water of the study area distribution characteristics and the development of oil and gas reservoir types, prediction of favorable target area and guide further oil and gas exploration aimed at characteristics of varied formation lithology, Complex distribution of sand body and only a few wells crossed the formation in The Permian strata in Tainan sag in Tuha BasinThe paper is adapted from the study of high resolution sequence stratigraphy, part of《Enrichment regularity study of Tainan sag and exploration target evaluation and optimization》.Mainly researching the Permian sequence series of Tainan sag area and the characteristics of sedimentary facies map and sedimentary microfacies map using sequence stratigraphy theory, making division and correlation of the bottom layer of the whole area combining previous research results with existing data, dividing sedimentary facies combining with the logging data and core description, making finely discrimination of sedimentary microfacies integrated all the information, and finally to forecast on the favorable reservoir area combining the dissection of reservoir and reservoir mainly controlling factors analysis.Through the analysis of the characteristics of the Permian sequence series in Tainan sag of Tuha basin in combination with logging data, we can find that the studied Permian target zone of Tainan sag can be divided into 3 third order and 14 fourth order: SQ1(subdivided into SI1~SI4)、SQ2(subdivided into SII1~SII4)、SQ3(SIII1~SIII6). Meanwhile, combining with previous working experience and the analysis of heavy minerals, the ratio of sandy and the plan about thickness distribution of sandstone, we will find:SQ3 mainly develop the southeast, east, west, three source, the largest source is the northwest southeast;the medium source is the Western content source to the northeast; the eastern provenance northward on a smaller scale.SQ2 is main development north provenance to the south.Based on 132 wells logging and lithologic data, unitary fine contrast 21 interface, the sedimentary unit fine stratigraphic level established; Rock electricity relation through the 34 coring core and logging curve, the study area was set up and carry out the logging facies, and with the study of 14 sedimentary microfacies of fine layers, it is concluded that: the purpose of Tainan sag are mainly developed fan delta, braided river delta, lake and other 3 kinds of facies. On the Karamay formation in deep lake and shallow lake sub facies, semi deep lake facies; Karamay formation mainly developed braided delta plain, braided delta front subfacies; On the Wutonggou formation mainly developed deep lake and shallow lake sub facies, semi deep lacustrine facies; In Wutonggou formation mainly develops shallow lake facies, fan delta plain and fan delta front subfacies; Under the Wutonggou formation developed fan delta plain and fan delta front subfacies, locally developed shallow lake, semi deep lake and deep lake facies; Along the river- tal Lang group mainly develops shallow lake, semi deep lake and deep lake subfacies, the local development of fan delta plain and fan delta front subfacies; Rare earth group mainly developed tehinnah volcano sedimentary facies.Through the anatomy of reservoirs in the study area, and the analysis of oil-water distribution rules and the mainly control factors of the reservoir, combining with sedimentary facies and sedimentary microfacies, we can determine the quality and the scope of distribution of favorable reservoir development, finally to determine the optimal target zone and the deployment location area. We find that the favorable enrichment structural belt of Permian Tainan sag is the Flaming Mountains fault zone, Lu Keqin Horst, Flaming Mountains, Horst and fire in northern slope belt, 4 port wells deployment. |
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