内蒙古二连断陷盆地陡带区地球物理响应及地震采集关键参数研究OA北大核心CSTPCD

The steep zone of graben basins was mostly deposited on the same fault side of the boundary of lake basins,with the characteristics of high mountains,steep slopes,near sediment sources,and fast sedimentation rate.It is often developed with alluvial fans,nearshore underwater fans,or fan deltas.In seismic facies,it is often manifested as wedge-shaped chaotic facies and wedge-shaped blank facies.The steep zone of the Erlian graben basin exploration area in Inner Mongolia described in this article is characterized by weak energy,low signal-to-noise ratio,and poor imaging in seismic data due to the deposition of a large amount of thick,elongated,and unsorted mixed debris material.In order to effectively improve the quality of seismic data in steep zone that cannot meet geological needs,this work analyzed a large amount of seismic data in steep zone,and conducted geophysical modeling and geophysical response verification of steep zone in the graben basin based on a thorough analysis of sedimentary patterns in these areas.It is believed that the lack of sorting and rapid sedimentation of a large amount of coarse debris material are the direct reasons for the weak reflection energy,low signal-to-noise ratio,and difficult imaging of seismic data in steep zones of the graben basin.Based on this,through sufficient theoretical argumentation,simulation,and actual data verification,it is recommended to use greater coverage times,suitable bin,wider azimuth,and appropriate offset for seismic data acquisition in steep zones of graben basins.This study can provide reference for seismic exploration in similar regions.