Research On Sedimentary Sequence Structure And Palaeogeomorphology Evolution Of Silurian In Tazhong Area

The tazhong area is an important oil and gas-bearing district of tarim basin. which is a typical large scale folding basin, which located in the west of China. With the guidance of the theory of Sequence Stratigraphy, Sedimentology ,Structural Geology and based on seismic reflection data, well loggings and cores, the paper set up isochronal sequence framework of silurian in tazhong area .tazhong area is divided into one second-order sequences,there third-order sequences which is SQ-Skp, SQ-Stt, SQ-Sym, systems tracts are subdivided according to the flooding surfaces.At establishment of chronostratigraphic correlation framework ,the paper research the kinds of deposition systems in tazhong area according to single well facies analysis, connect well contrast and seismic attribute analysis, The research indicates that the TST of the SQ_Skp sequence mainly with estuary - tidal depositional system, braided delta system, the HST of the SQ_Skp sequence consist of tide dominated delta front and Tidal depositional systemPalaeogeomorphology character of each sequence in silurian in tazhong area is restored through the erosion and remaining thickness. palaeogeomorphic presented south direction higher than north direction. Overall palaeogeomorphic can be divided into high-uplift zone, the low uplift zone, slope and depression. the palaeogeomorphic has certain control influence towards studying area depositing system of timespace collocation regulationCombined with palaeostructure, sedimentary systems and palaeogeomorphic of silurian in tazhong area. The favorable traps is divided into anticline traps,lithologic-structural traps and onlap unconformity stratigraphic trap and erosion unconformity stratigraphic trap. anticline traps is mainly distributed in tazhong 47 and tazhong 11 well field. lithologic- structural traps is mainly distributed in tazhong 12 tazhong 50 and tazhong 30 well field. onlap unconformity stratigraphic trap is mainly distributed in the slope of the north of tazhong area near manjiaer depression. Erosion unconformity stratigraphic trap. is mainly distributed in southern uplift and erosion aera.