BeachBar Depositional Laws and Controls of the 2nd Member of Shahejie Formation in Zhuangxi Area, Zhanhua Sag

Key words: 
• Zhuangxi area

Abstract: With the improvement of our national oil/gas exploration, beachbar depositional system has become another kind of favorable reservoir in the continental petroliferous basins, and depositional laws and influential factors are its emphasis and difficulties. This paper, based on highresolution sequence stratigraphy theory, though the analyzing of core, well log, logging curves, divides and correlates strata in the 2nd member of Shahejie Formation. On the basis of identifying and classifying different kinds of sedimentary facies, a fine study about clastic beachbar and organic bank has been done. The results show: ① Organic banks and sand beaches, located in a flat, wide area, have thin single layers and wide distribution; ② Sand bars, located in a slope with a certain angle, and rugged terrain area, have thick single layers and narrow distribution; ③ Palaeotopography and risingdown base level cycles are the controlling factors in beachbar deposits around buried hills of fault basin. Meanwhile, also indicates beachbar deposits around Zhuangxi buried hill have good capacity and petroleum resource potential.