Sedimentary face and reservoir characteristics of ES4 in the east slope of Niuzhuang Sag

The forth segment of Shahejie formation （ES₄） is a new oil-bearing series found in the east slope of Niuzhuang Sag since 2004. The sedimentary face was determined by turbidite fan of remote origin through study of lithology, grading analysis and sedimentary structure, etc. South area of Niuzhuang Sag is the material origin area of the fan, and braid channel microface of middle fan is the main oil-bearing microface. ES4 reservoir in Niuzhuang belongs to lithology or structure-lithology reservoir with middle to high pressure, middle permeability, and low resistance. The sand body of reservoir is thick, and physical characters are advantageous.