Forward Modeling Oriented Target Imaging And Its Accuracy Analysis

The exploration and development of concealed reservoirs is more and more demanding for the information of seismic results,and the geological objects and geologic targets are getting smaller and smaller,so the requirements of imaging accuracy are getting higher and higher.In the process of actual seismic data processing,the analysis of imaging accuracy often lacks of quantitative analysis.At the same time,the choice of technology and key parameters depends mainly on experience and few systematic researches,and the analysis of the imaging accuracy of the target interval The optimization of research and technology can provide better help for the target processing of actual seismic data.Based on the previous research results,this paper first analyzes the geologic and geophysical characteristics of the typical lithologic reservoirs in Shengli Exploration Area,and establishes a geological model that can accurately reflect the characteristics of the reservoir.Secondly,through the numerical simulation of forward modeling,Prestack forward forward recording,forward resolution processing for forward recording,and analysis of the impact of the imaging accuracy of the target interval;Finally,combined with the actual data to complete the target layer to improve the resolution processing.In the course of the study,the establishment of two geological models of turbidite body and channel sand body has been completed.Followed by the forward modeling method of wave equation with better amplitude preserving,the precision of forward modeling is ensured,The computational efficiency is improved.For the turbidite body,the prestack data of 400 canals and 1000 canals of the channel sand body are forwardly obtained.Prestack forward data are used to qualitatively analyze the key processing techniques and parameters for improving the resolution At the same time,a set of methods that can be used to quantitatively analyze the resolution parameters has been formed by using the dominant frequency,effective bandwidth,low-frequency effective information and effective bandwidth proportion analysis as a means.In the actual processing,Covering a total area of 286km2)and Linnan 3D(covering a span of 195km2).The frequency of the target interval data has been raised above 5Hz.Through this research,a new idea of directing the target processing of actual seismic data by forward modeling has been formed.At the same time,it can provide technical reference for further research on imaging accuracy of the target interval in the future.