Identifying the Types of Formation Anisotropy by Using the Dispersion Property of Crossed Dipole Acoustic Data

The fast and slow flexural wave crossover phenomenon in anisotropic formation caused by uneven in-situ stress is used as theoretical bases. A continuous phase spectral method for extracting phase slowness dispersion curve is introduced. The method is deployed to process the crossed dipole data, thus to identify the types of anisotropies from the dispersion characters of fast and slow flexural waves, those types include:①the coincidence of dispersion curves of anisotropic formation; ②the parallel of dispersion curves of inherent anisotropic formation; ③the crossover of dispersion curves of stress induced anisotropic formation.