Pre-stack Depth Migration Of Anisotropic And Its Application Research In Founder Prosperous Region

Founder of Daqing peripheral basin down-faulted prosperous area data of low S/N,poor continuity of seismic profiles in phase axis,deep imaging effect is not ideal,This kind of situation can't satisfy the demand of geological personnel for fine interpretation.At present,With the great development of computer technology and seismic data processing technology,the seismic data imaging precision demand is higher and higher.Conventional post-stack time migration,pre-stack time migration can't obtain ideal effect,especially in the mountainous region,piedmont,transitional change of lateral velocity larger areas,often can cause structural imaging appearance.Pre-stack depth migration technique can not only adapt to the horizontal change,the speed also can meet the target of the geological body real space position,at home and abroad in recent years,it has become the development trend of seismic data imaging and important technical means.Because the underground medium anisotropy,resulting in the seismic imaging depth and the depth of the stratum depth there is a certain error.Most of the reservoirs in the world are transversely isotropic and longitudinal for anisotropic,VTI medium model is the most common research of anisotropic model.This paper mainly through to the anisotropy(VTI)of medium pre-stack depth migration theory analysis and research,combined with actual data application,prosperous region founder developed a modeling method is suitable for the region's speed,eventually won the complete anisotropic pre-stack depth migration process.Specific contents are as follows: firstly,Basic theory of anisotropic pre-stack depth migration system is introduced,including the definition of anisotropic medium,anisotropic medium matrix parameters involved,acoustic wave equations in anisotropic medium and simplified analytic and so on.Secondly,for anisotropic velocity modeling were studied.Speed breaks through the traditional modeling method,this paper on the basis of tomographic imaging with mesh modeling,and each other in the time domain and depth domain conversion velocity model optimization iterations,the final combination percentage velocity scanning final isotropic velocity model,combining work area of drilling and logging data calculation of anisotropic parameters,and update the anisotropy parameters through multiple iterations,get the migration velocity model of anisotropic medium,to complete the final data migration.Through the analysis of the final treatment effect,the anisotropy of prestack migration profile imaging accuracy improved obviously,deep structure more clear,more focus on energy.Depth the purpose of final results better agreement with the layered depth inoue,and eliminates the depth error,illustrates this article provides a set of reasonable and practical treatment process,to advance in the future in complicated structure area to carry out the anisotropic pre-stack migration research has important practical significance.