Research On Full Waveform Inversion Method Of VTI Media And GPU Acceleration

Using the seismic amplitude and phase,full waveform inversion can estimate more accurate subsurface parameters to minimize the difference between synthetic seismic data and real data.It can provide an accurate velocity for pre-stack time migration and pre-stack depth migration and provide reliable velocity data for lithology recognition.In recent years,seismic exploration targets have become more and more complex,and the accuracy requirements for seismic exploration techniques are getting higher and higher.Since the actual earth medium is anisotropic,most sedimentary rocks can be approximated as transversely isotropic media.Under the background of the current high-precision seismic exploration,the full waveform inversion of VTI media has become a research hotspot.Using the pseudo-acoustic wave equation instead of the elastic wave equation to simulate,not only can the propagation information of the effective wave be well preserved,but also the associated acoustic wave parameters are greatly reduced compared with the cumbersome elastic wave anisotropy multi-parameter,thus retaining the calculation accuracy and Based on the feasibility and reliability of the method,acoustic approximation is one of the effective methods to simplify the anisotropic elastic wave simulation and reduce the amount of calculation.In the basic theory of full waveform forward modeling and inversion,the basic theory of wave equation is introduced from geometric equation,constitutive equation and motion balance equation respectively.Secondly,the relationship between Hooke's law and q P-q SV wave dispersion in VTI media is derived.The first-order q P wave equations of different forms of VTI media are derived,and the pseudo-acoustic wave forward modeling of VTI media is carried out by using the staggered grid finite difference method.Then several commonly used nonlinear inversion methods are introduced,and the accompanying state method is introduced.The gradient is deduced.Finally,the parametric analysis of the anisotropic medium model is introduced.The radiation pattern method is used to analyze the three types of parametric characterization and the interaction and trade-off between each parameterization.At the same time,the model trial calculation was carried out to verify the feasibility and correctness of the method.