Research On The Sandy Debris-flow Sedimentary Characteristics Of The Paleogene In The South Of Nanpu Sag

This paper is based on using the well and seismic data in sequence stratigraphic division,by making full use of the core,drilling,logging,testing,and seismic data,based on the use of core analysis,logging facies analysis,seismic attribute analysis,seismic facies analysis technique determining the Nanpu Sag southern tectonic development on the 3rd sandy debris flow deposits.Based on the completion of region of interest provenance analysis,depositional systems analysis and sedimentary facies analysis,I analyze the Nanpu Sag southern Paleogene sandy debris flow deposition characteristics.Based on these studies,I analyze the deposition condition and formation mechanism of sandy debris flow deposits in the study area,and sum up the main controlling factors of sandy debris flow deposits.Finally,I establish depositional model of sandy debris flow deposits in the study area.I draw the following main conclusions:(1)In order to clarify the sedimentary background and sedimentary environment of sandy debris flow deposits in the space.With the core observation and drilling data as the basis,combined with the rock electricity relation and seismic attribute analysis technology,completed the study in the south of Nanpu Sag,depositional systems and sedimentary phase.The results showed that: Nanpu Sag southern provenance from three directions-the South Stream provenance in west,south and north east provenance,mainly controlled by the sand barrier field projection;deposits of mainly braided river Delta-Lake-gravity flow depositional system and fan delta-lake-gravity flow depositional system;depositing main types of braided river delta deposit,fan delta,gravity flow deposits and lake sediments.(2)Through the method of core observation,log feature analysis and seismic reflection feature analysis,under the guide of sedimentology and the research of depositional system and sedimentary facies,I consider that the study area develop sandy debris flow deposits in Nanpu No.3 step-fault zone the first part sub-member of Shahejie Formationm and Nanpu No.2 step-fault zone the lower part of the third part sub-member of Dongying Formationm.(3)By size analysis,core analysis,logging response analysis and seismic reflection characteristics analysis,we analyze Nanpu Sag southern sandy debris flow deposition characteristics from a single well,a cross-sectional and plane of the three dimensions.Object of study is a massive sandstone in the deepwater environment with more than 10 m thickness,mixed size,separation not good,rounded moderate-poor,massive structure,many erratics in the upper and middle common boulder;in the performance of the two-stage probability curve shows that CM Fig substantially parallel to the C = M baseline,and sorting coefficient appears as poor or very poor.What is more,sandy debris flow deposits developed in the deep lake-semi-deep lake environment often associated with turbidity deposition.And the plane is irregular tongue-shaped.Logging curve for pectination,deep lateral resistivity higher,with a mean at 75?.m;The earthquake shows high amplitude seismic wormlike minor features.(4)I have analysed the forming condition,genetic mechanism and main control factor of Nanpu Sag sandy debris flow.Comprehensive analysis shows that plenty of provenances is a prerequisite sandy debris flow deposits,is the material conditions of studying area produce more stacked sand body.Sham or hydrostatic formation and preservation of the environment is sandy debris flow deposits in favorable places.Ancient topography and sedimentary fault decides sandy debris flow distribution patterns and deposition method(along a vertical fault or fault).And Much of volcanic activity and the earthquakes it caused is the main mechanism that triggers sandy debris flow deposition.(5)I establish the Nanpu Sag southern Paleogene sandy debris flow deposition model as: the plot-accretion of sand body from braided river delta front or fan delta front,triggered by volcanic eruptions and other factors,lose balance in Sham dash and slide,collapse under the control of action fault in the deepwater semi-deep lake.This process forms sandy debris flow deposits that have potential for oil and gas exploration.