Study On The Sedimentary Facies And Sand Body Spreading Characteristics Of Member4of Quantou Formation In North Of Honggang Area, Songliao Basin

Songliao Basin is a large Mesozoic-Cenozoic continental petroliferous basin withboth faulted structure and depression structure, which can be divided into north partand south part. North of Honggang area is an important area in south of SongliaoBasin. Based on the exploration and development status of north of Honggang area,this paper study on the sequence stratigraphy and depositional system characteristicsof Member4of Quantou Formation in north of Honggang area, with the using of thetheory and technology of high-resolution sequence stratigraphy, and Summarize thesedimentary microfacies’ and the sand body’s spreading characteristics. The leadingconclusions are as follows：Based on the comprehensive analysis of drilling data, logging, cores, and seismicdata,6types of sequence boundaries and the flooding surfaces have been recognized.According to the comparison of10sections, a half of long-term(rising systems tract ofLSC1),4middle-term(MSC1~MSC4),9short-term(SSC1~SSC9), super-short-term(SSSC1~SSSC22) cycle sequences can be distinguished form Member4of QuantouFormation. The structure types and distribution mode of Every level’s cycle sequenceshave been analyzed and described.According to principle of isochronous contrast, we choose the sequenceboundary and flooding surface of middle-term cycle sequence as the frame ofisochronous stratigraphic correlation, the short-term cycle sequence as the skeleton,and the super-short-term cycle sequence as the correlation unit, and then, establish thechrono-stratigraphic frameworks of Member4of Quantou Formation.Based on the recognition of depositional system symbol and the comprehensiveanalysis of tectonic evolution of the Songliao Basin, we developed that thesedimentary system of Member4of Quantou Formation, in north of Honggang area is mainly composed of (shallow water) delta in lake and delta system, then analyzedand described every subfacis’ and microfacies’ characteristics.In the established frame of isochronous stratigraphic correlation, based on thecomparative study of sections, we obtained the developmental and connectivecharacteristics of the sedimentary facies and sand bodies.In this paper, we choose the super-short-term cycle sequence as the time units,the microfacies as the sedimentary units of the sand body thickness contour,sandstone/strata contour, sedimentary environment mapping, analyzed and describedmicrofacies’ and sand bodies’ plane distribution features at every time units, andsummarized the sequence lithofacies and paleogeography characteristics andevolution characteristics of Member4of Quantou Formation in north of Honggangarea.