Multi-wave Velocity Analysis In VTI Media And NMO Correction

Converted wave due to ray path asymmetry, even for the horizontal layeredmedium, converted wave CMP gathers are no longer common conversion point gather.For the same channel, the received reflected waves, the reflection point horizontalposition with the reflector depth deepens gradually to the bit location near. The traveltime and offset relationship is not a hyperbolic relationship, which adopts hyperbolictime-distance equation treatment will produce bigger error. Therefore, thedevelopment of converted wave data processing is very necessary.Conventional NMO correction will generate serious stretch at long spread event.In this paper, we describe a new implementation of the NMO correction that isapplied to P wave reflection data,which called nonstretch NMO. We illustrate the useof nonstretch NMO by applied it to synthetic data and get good resistent stretch effect.According to the velocity analysis and NMO as the object of study, and improvethe precision of velocity analysis has my own opinion. Based on the previous work,this paper introduces one velocity estimation factors on the resolution of velocityanalysis and has realized one high resolution velocity analysis method—theconvariance measure. Furthermore, the high resolution velocity analysis method wasused in converted wave velocity analysis. Meanwhile, it aims at the conversion pointformula and chooses the best conversion point solution formula, which is applied toCCP gather sort based on the time window. This process is going along with the highresolution velocity analysis method in order to achieve the converted wave velocityanalysis. Then study the multilayer VIT medium wave time-distance curve equation,and according to the C principle, combined with covariance matrix eigenvaluevelocity analysis, on multidetector VTI medium were converted wave velocityanalysis.