The High-Resolution Sequence Stratigraphy and Depositional System Study of Eogene Hongxing Area, Eastern Depression of Liaohe

Guided by high-resolution sequence stratigraphy theory, combined with lots of logging data and core observation, areservoir-scale high-resolution sequence stratigraphy framework of the Eogene first member of Shahejie for mation and the third member of Dong ying fo rmation has beenest ablished in Hongxing area. 43rd order sequences and 194th order paramsequence sets and series of 5th order paramsequences have been classified in this paper. Acco rding to the logginganalysis and coreobservation, several of sedimentary microfacies of Sha1 and Dong3 have been recognized, such as fandelta front sub-distritary channel, mouth bar, front delta, flooding fan, distributary interval and soon. The depositional systems mapping of 4th order sequence show that different sedimentary microfacies form different sand configuration and distribution and physical characteristic of reservoir. Because fan delta front sub-distributary channel or distribut ary channel is the major depositional microfacies of Sha1, the reser voirmainly is coarsegrade and single thick sand. While braided or braided delta is the major depositional system of Dong3, the reservoir mainly is fine grade and single thin sand. In literally, there shows the evolutiont rend from northeast and southwest distributaries channel sand to delta front far barsand. The distribution configuration of depositional system controlled the sand types and distribution.