A Study On The Es3 Sequence Stratigraphy And Sedimentary Microfacies In Leijia Region Of Liaohe West Depression

In Leijia region of Liaohe west depression,there are good geological conditions for trap forming.Base on the theory of sequence stratigraphy and the data of seismic,logging,well-seismic,sequence boundaries had been identified and classified.In this paper,Es3 had been divided into three sequences: SQ1,SQ2 and SQ3,which basically correspond with lower Es3,mid Es3 and upper Es3.The major types of sedimentary facies in Leijia zone are fan delta and lacustrine facies,which changes rapidly in east-west,stablely in north-south.The sequence of development in Es3(from east to west)are: fan delta plain,fan delta front,the front fan delta and the semi-deep to deep lacustrine sub-facies.The distribution of fan-delta system in Sub-section(SQ1)of Lower Es3 are largest and farthest(westward),secondly are Sub-section(SQ3)of upper Es3,Sub-section(SQ2)of mid Es3 is smallest.According to the comprehensive analysis of hydrocarbon source rock,reservoir,reservoir-cap,hydrocarbon migration and trap conditions,it can be predicted that: there are 4 favorable exploration zones in this region.