Method to extract anisotropy parameters from MPAL logging data

Multi-pole acoustic array logging tool (MPAL) is new designed acoustic logging tool. This paper proposed a new method to extract anisotropy parameters from the four-component dipole waveforms measured by MPAL. The method extracts anisotropic parameters by four steps, including rotation of four-component waveforms, matching of fast and slow waves, improvement of the resolution of anisotropy and obtaining of the final slowness of fast and slow shear waves. Different from the traditional method, the new developed method obtains high resolution anisotropy parameters based on the control of low resolution anisotropy and an error feedback method. The results of field examples show that the proposed method is fast and stable for anisotropy analysis and fracturing evaluation.