Research Of Sedimentary Fades Evolution Of Jurassic In Kebai Area In The Notrhwestern Margin Of The Junggar Basin

Jurassic is one of the main oil and gas exploration strata in the Junggar Basin,theexploration acreage of Karamay-Baikouquan is2005km2. Predecessors have carried outsome research including geological, stratigraphic and sedimentary facies,but the studies inreservoir rock characteristics and sedimentary characteristics are not systematic, detailedstudy of sedimentary microfacies dabble less. Based on previous studies, this articleintegrated using seismic, drilling, logging and laboratory analysis to research thestratigraphic division, source direction, sedimentary characteristics, vertical and horizontaldistribution of sedimentary facies,and achieved results and understanding as below:7Comprehensive studied the sandstone composition,compositional maturity,heavyminerals,formation thickness,percentage of glutenite other characteristies,the targetformation’s provenance in the study area was analyzed, the results show the provenance hasa good inheritance in each group, there are two main directions of provenance:one is ZaireHill in the south-west,the other is the Interchange of Zaire Hill and Sahara Alat Hill in thenorth-west.8Though analyzing the lithology, sedimentary structure, particle size characteristicsand electrical characteristics in the study area, this article has Ident ified the sedimentaryfacies marks and made a single well sedimentary facies.9Combined with analysis of single well faeiesand profile correlation,depositionalsystem of the target formation was shock fan-braided river-braided river delta. Badaowan,Xishanyao, Toutunhe have mainly developed braided channel facies, floodplain facies andbraided river delta plain. Sangonghe and Qigu have mainly developed braided channel facies,floodplain facies.: In the background of the basin evolution, sedimentary Jurassic study area longitudinal planeprofileand sedimentary layers of the phase diagram, analysis of Jurassic sedimentary facies evolution:Badaowan formation sedimentary period, the basin of braided river and braided river deltasedimentarycharacteristics, humid climate, the formation of coarse clastic sedimentary coal bearing.Sangonghe formation sedimentary period, due to the northwestern margin of the Zaire mountain uplifteffectlayer, the study area mainly developed braided river facies, sedimentary period, the basin experienced large-scale invasion of lake, the center of the sag delta facies, Zaire mountainsourceformation of braided river delta sedimentary enormous. Xishanyao formation sedimentaryperiod, the western basin uplift resulted in deposition ofdeletion, near the Zaire mountain side of braidedriver is widely distributed, the lake area only distributed in the depression center; research areas of thePiedmont depression center transition tostill rely on Zaire mountain source formation of braided riverdelta sedimentary huge, the climate was warm and wet the formation of flooding, large-area marsh,swamp, Binhu river swamp environment, become the heyday of coal seam. Toutunhe formationsedimentary period, piedmont is characterized by the deposition of braided river, the center of the sagbasingradually narrowed, research on large area deposition of delta plain. Qigu formation sedimentaryperiod, the tectonic activity is more active, fast denudation,rapid deposition formation, lithology withred (dark red) deposition, dry climate; the braided riverfacies feature, formation were denuded, seismicprofile display for the truncated contact relationship.