Stratigraphic framework and the analysis of sedimentary facies in Talahaxi

Based on the theory of sequence stratigraphy,we have carried out a detailed research on the stratigraphic framework and sedimentary system of Talahaxi.According to the seismic profile's and lithology-electrical materials' characteristics of the sequence boundary,the intended zone which were member 4 of Quantou formation to member 3 of Nenjiang formation was divided into two second-order sequence,six third-order sequence and seventeen fourth-order sequence.Comprehensively using the core,well logging and seismic materials,we determined the sedimentary characteristics in the sequences.Comprehensively analysis indicated that the facies of the intended zone are mainly delta deposition and lacustrine sediments.According to the characteristics of the sequences,we determined the plane distribution rule of the intended zone.The facies of the western research area are mainly delta plain facies,distributary channel sand,sheet sand and river mouth bars,but mainly littoral and shallow lake,semi-deep lacustrine in the eastern.By the analysis of the characteristics of the system tracts in the sequence,we know that the formation mainly consisting of sandstone in sand group is obviously under the control of the fourth-order sequence boundary,the sequences and the sand groups have good corresponding relationship.