| Deep seismic reflection profiling has become an internationally recognized technique to expose the fine structure of the lithosphere,and can explain the formation mechanism and geodynamic process of the deep structure of the lithosphere through fine structure of the lithosphere.Its data acquisition is based on the basic theory of petroleum seismic exploration,using the same equipment and technology,and using different acquisition parameters.It is mainly used for large explosion charge and large offset,long recording time reception to obtain deeper reflection information underground.At present,the processing flow and processing method of petroleum exploration are still used.However,deep seismic reflection data has its particularity due to its different geological tasks and explosion parameters.The processing methods of petroleum exploration and processing technology cannot retain the effective reflection of the whole crust.Northeast China has experienced multiple periods of tectonic evolution and has a complicated history of tectonic evolution.It is an important area for deep seismic reflection exploration research.This article uses the seismic data of two deep seismic reflection survey lines,which span four major blocks in the northeast region.Take this as an example to analyze and explain the characteristics of deep seismic reflection profiles,and introduce them in combination with the characteristics of deep seismic reflection data.Data processing methods are proposed to adapt to the imaging technology of deep seismic reflection profile.The original single shot can provide real underground information.This article selects a typical single shot for feature analysis,and analyzes the root causes of its weak energy and low signal-to-noise ratio based on the characteristics of the single shot in the igneous rock area.In response to the full-crust imaging requirements of deep seismic reflection profiles,this article introduces different noise suppression methods and energy compensation methods.The focus is to ensure effective signal imaging in the deep layer.At the same time,static correction processing and high-precision velocity analysis are done to lay a foundation for accurate imaging.basis.After fine processing of seismic data,this paper focuses on the basic principles and implementation methods of key technologies such as near vertical reflection technology and single coverage technology,CRS common reflection panel imaging,and pre-stack time migration.Among them,it is based on near vertical reflection theory.The calculated closeoffset stacking,combined with the deep reflection morphology of a single coverage profile with high signal-to-noise ratio,constrains the structural framework of the Moho surface;CRS common reflection surface element stacking technology performs the reflection waveforms in the Fresnel zone Superposition can enhance the energy and continuity of the effective deepseated signals;it is difficult to construct a velocity model for deep seismic reflection data due to too long receiving time,and the pre-stack time migration imaging effect is poor.Most of the time,post-stack time migration methods are used to reflect the real underground structure.This paper uses two survey lines to test the application of pre-stack time migration technology in deep seismic reflection data. |
