关键词: 塔中地区, 断裂坡折带, 构造特征, 构造变换带, 勘探领域

Abstract: Based on the new 3D seismic data, the complex structural characteristics and the difference of oil and gas accumulation in Tazhong No.1 Structural Zone were studied with the isochronous sequence framework and structure analysis. It is indicated that Tazhong No.1 Structural Zone is a complicated faulted slope break resulted from a large thrust belt eroded for a long time from the end of the early Ordovician to the early of the late Ordovician. A composite of carbonate reefs and banks of platform margin in Lianglitage Formation of the Upper Ordovician was developed along the carbonate slope break. Tazhong No.1 Faulted Slope Break can be divided into five parts with different geometry and development characteristics by the accommodation of transfer zones,which caused the difference of oil and gas accumulation. The thick composite of carbonate reefs and banks in rimed shelf is located in the Tazhong-44 Block. This area is the favorable exploration district and has high and stable production of carbonate along the slope break. There are intensive structural effect and Karst process in Tazhong-45 Block. This area has an advantageous prospect for a large scale fracture-hole reservoir. The two zones are main exploration targets for large oil and gas fields.

Key words: Tazhong area, faulted slope break, structural characteristics, tectonic transfer zone, exploration field