Research On Processing Technology Of Engineering Reflection Seismic Data In Loess Overburden Area

Seismic exploration is one of the most effective methods for engineering geological exploration in loess overburden areas.Due to the complex geological conditions(loose soil,poor elasticity,landslide,fault,dark hole development,etc.)in the loess overburden area,and the nature of engineering seismic exploration,the seismic data have the following characteristics: short receiving arrangement,relatively small channel distance,uneven reflected wave energy,narrow frequency band;The source interference wave is relatively strong and the wave field is complex.This brings great difficulty to seismic data processing.Based on the engineering geological problems of loess coverage area of the geological model is set up,and the characteristics of the seismic data forward modeling analysis,on the basis of the focus on to improve the signal-to-noise ratio and resolution of seismic data processing and migration imaging technology research,and combined with the actual data processing,forming a system of area covered by loess in the engineering seismic data process,and then for the area covered by loess in the engineering construction to provide reliable data processing.Firstly,by analyzing the seismic response characteristics(amplitude,frequency,etc.)of different geological anomalous bodies and the propagation rules of various waves through forward modeling,the paper concludes that the problems mainly focus on three aspects:comprehensive denoising,resolution and migration imaging.In view of the low SNR problem,this paper on the coherent noise suppression in multi-domain united denoising method research,according to the characteristics of all kinds of seismic wave and the characteristics of different domain filtering,selecting opposite the f-k filtering wave suppression,predictive deconvolution,f-k filtering,the east transform filter joint suppression of multiples,through the theoretical model data and real data processing to analyze the feasibility and validity of the method;Aiming at the problem of low resolution,the relationship between the main frequency and the resolution was analyzed by forward modeling simulation,and the surface consistent deconvolution and pulse deconvolution technologies were studied.Combining the advantages and disadvantages of the two technologies,the neutron wave consistency was strengthened and the frequency band was widened and the resolution was increased in the actual dataprocessing.Migration imaging,in view of the area covered by loess in the engineering geologic abnormal body precise imaging problems using prestack migration imaging method for processing,the prestack time migration imaging parameters(migration aperture,offset Angle),focus on imaging velocity model for research,establishment of actual seismic data imaging processing application has achieved good results.According to the above experimental research and analysis,a set of systematic seismic data processing process in loess overburden area is formed,and a good result is achieved in combination with the actual data processing.