Analysis Of Sedimentary Facies And Sand Distribution Of Silurian In The Central Uplitf Of Tarim Basin

The main reservoir to trap damage is very serious of Silurian in Tarim Basin, the paper use logging, drilling, seismic data and sedimentary facies, using the principles of sequence stratigraphy, carried out a detailed sequence stratigraphy and depositional systems for the sand distribution, the main research results as follows:(1) Defined Silurian of the central uplift in Tarim Basin stratigraphic framework. It is mainly based on seismic, logging, core with the principles of the Silurian strata, which divided into three third order sequences (sq1-sq3), identified six systems tract and 3 kinds of interface types, Kepingtage identified on the three sub-paragraph and four order sequences (sq1-1 sql-4).(2) In the third-order sequence stratigraphic framework, analysis the sedimentary facies of the Silurian in the central uplift strata, depositional systems and sand distribution. Drilling data analysis showed that the main development of Silurian tidal flat, shore, braided river delta and the shallow continental shelf sedimentary systems. Microfacies types are sand flat, mixed flat, mud flat, tidal channel, tidal creeks, mud flat-salt marshes, tidal sand bar and so on. The results show that, sql is mainly about Tower East Silurian shore environment for the formation of sedimentary system, west to the tower in the context of regional tidal flat deposits,the west is the shore and shallow continental shelf sedimentary system. sq2 is the shallow shelf and tidal flat deposits. sq3 is the tidal flat and shallow shelf sediments, which develop in the tower east shore deposits. sq4 is mainly shore-based. Overall, Silurian of the central uplift in Tarim Basin is transgressive system tract shore - shelf depositional system, high system tract development of tidal flat sedimentary system.(3) The third sub-section of Kepingtage in Silurian of low uplift in the tower depicts four kinds of sand bodies, and then analysis their vertical evolution and distribution of surface features. The sand of the third sub-section are distributed in the tower, it is thick in the North and thin in the South,the kind of rock are mainly the sandstone, fine sandstone and siltstone. The sedimentary facies from North to south is the tidal flat to shore, shore to the tidal flat, tidal flat to tidal shore. Overall lower sandstone tower can identify four sand bodies, including second and third sand distribute wider then the fourth sand distributy.. (4) The third sub-section of Kepingtage in Silurian the most favorable horizon. The sand of coastal tidal and cover to the mainland of the Silurian over the formation of pinch-out stratigraphic are easy to be trap, and isolated in a shallow sand bar outside the mud shore is easy to be traps.The four kinds of sand are favorable to explore, and the sand is easy to be the stratigraphic overlap traps, sand lens traps, lithologic updip pinch out trap and gully filled with traps...