The Research Of Gaussian Beam Migration In Viscous And Anisotropic Media

Conventional oil and gas exploration targets have not met people's demand for oil and gas exploration.Small and medium-sized complex hidden oil and gas reservoirs have become new targets for mining,at the same time the corresponding difficulty in exploration has also increased.Seismic data processing technology is a core part of seismic exploration technology and an important research branch in geophysics.Its main purpose is to restore the spatial characteristics and reflection coefficients of the reflective interface by spatially relocating the reflected waves,thereby improving the spatial resolution and fidelity of the seismic exploration,and providing good seismic profile for seismic interpretation and reservoir prediction.The real underground medium is the existence of complex media such as viscosity and anisotropy,while the traditional seismic migration imaging technology is based on the ideal condition that the underground media is completely elastic.Therefore,in the viscous media,using the traditional assumption methods for seismic data processing in anisotropic exploration areas will inevitably lead to inaccurately-resolved seismic reflectors,lower imaging resolution,and other issues,affecting subsequent seismic data interpretation and reservoir prediction.In the exploration industry,seismic migration imaging technology is an important research method for understanding underground structures and performing accurate imaging.Therefore,seismic migration imaging technology plays an important role in oil and gas exploration.Considering the current massive seismic data,it is necessary to balance the imaging accuracy and computational efficiency when performing seismic wave migration imaging processing.However,in reality,we want to achieve a higher imaging quality profile while also having better computational efficiency is very difficult.Currently,the ray prestack depth migration method commonly used in the industry is the Kirchhoff migration method.The advantage of this imaging method is that the imaging speed is high and the calculation efficiency is high,but the disadvantage is that the accuracy of the imaging results is low.And the imaging quality pictured by reverse time migration is better,but this method is at a disadvantage in computational efficiency.The Gaussian beam pre-stack depth migration method is an upgraded and improved ray migration method.This improved migration method has the advantages of high imaging quality and high computational efficiency.At the same time,it has high flexibility and is suitable for the development of various new methods.Therefore,Gaussian beam migration has a high application prospect and research value.In recent years,domestic and foreign scholars have carried out a lot of research work on Gaussian beam migration methods in various media,but the content of the research is often just for Gaussian beam migration in a specific medium,and research for having two kinds of complex media at the same time is still rare.The object of this article is Gaussian beam migration method.In this paper,on the premise of ensuring high Gaussian beam computational efficiency,the complex media Gaussian beam migration method of viscous anisotropic media is developed,which further extends the application of Gaussian beams.The main contents of this dissertation are as follows:(1)This paper constructs a Gaussian beam from Gaussian beam theory and discusses the influence of several parameters on Gaussian beam morphology.At the same time,it explores the impact of transmission patterns for Gaussian beams due to viscous and anisotropic media;(2)This paper introduces the principle of conventional Gaussian beam migration and considers the effects of viscous and anisotropic media on seismic wave migration.At the same time,the ray tracing equations are modified in complex media and the complex values of travel time in Gaussian beams are corrected,thus develops the conventional Gaussian beam depth migration method into a complex medium;(3)Gaussian beam imaging conditions are considered in this paper and a preserved amplitude Gaussian beam migration method is obtained by applying deconvolution imaging conditions.This method is applied to complex media with viscous and anisotropic media.Finally,the correctness of the model trial is verified.