The Sequence Stratigraphy Model of Shahejie Formation in Diannan Area

Key words: 
• sequence stratigraphy model

Abstract: With the application of the principles of sequence stratigraphy， Shahejie formation of Paleogene in Diannan Area is divided into six 3rd order sequences ，seventeen system tracts by the identification marks of sequence boundary including seismic section， well logging curves， lithocombination and so on. Without lowstand systems tract in the sequence Ⅰ,the sequence Ⅱto sequence Ⅵ are all composed of lowstand systems tract, transgressive systems tract and highstand systems tract. Based on the division and correlation of the sequence stratigraphy units two sequence stratigraphic models with different genesis including the fault slopebreak and sedimentary slopebreak are established. The relations between the models and the distinction of lithologic hydrocarbon reservoir indicate that low stand fan and stratigraphic overlap hydrocarbon reservoirs are usually located below the slopebreak， and unconformity， beachdam lens reservoirs are usually located on the top of slopebreak.