The Technology And Realization Of Extract Shear Wave Slowness From Flexural Wave

Acoustic logging can provide important parameters for oil exploration and development,the study of the theory of the flexural wave is an important subject of acoustic logging,using flexural wave to extract shear wave velocity of formation evaluation,well logging instrument design and so on are all have important significance.In this paper,the horizontal wave velocities of strata extracted by dipole wavelet are studied from three aspects.Through a given formation and borehole parameters calculation of dipole wave dispersion curves,by a given stratigraphic information forward bending wave waveform in soft and hard formation,through weighted spectrum waveform correlation method,the Prony method of dealing with the synthetic theory,through the weighted spectrum correlation method,the Prony method to actual formation data,and analyze the treatment effect of evaluation.In this paper,the frequency dispersion characteristics of curved waves are studied by solving the frequency dispersion equation of curved waves.By changing the parameters of the model,such as formation density,hole radius and sound velocity of longitudinal wave shear wave in the fluid,the frequency of curved wave is studied with slowness.The variation curves of group velocity and phase velocity with frequency of flexural wave in soft and hard strata are calculated under given formation conditions.The center frequency is 3 KHZ Ricker Wavelet,real axis integration was used to simulate the fast and slow formation of dipole array waveform,through the normalized processing,contained the flexural wave,amplitude is consistent with the theory.Respectively using weighted spectrum correlation method and Prony method to forward the dipole array waveform,calculated the soft and hard strata under the condition of flexural wave dispersion curves,and forward the flexural wave dispersion curve,found the basic are the same,verify the accuracy of using these two methods.Using Prony method and weighted spectrum correlation method for frequency slowness relevant figure in the low frequency fitting,get low flexural wave slowness,the result and forward the shear wave slowness.Finally,by using these two methods to process the actual dipole acoustic logging data,the shear wave slowness of the actual formation is obtained.