Design of a cross-dipole array acoustic logging tool

• Published in: Petroleum science 2008-05, Vol.5 (2), p.105-109
• Main Authors: Lu, Junqiang, Ju, Xiaodong, Cheng, Xiangyang
• Format: Article
• Language: English
• Subjects: Acoustic waves; Acoustics; Anisotropy; Azimuth; Boreholes; Circuits; Data acquisition; Dipoles; Earth and Environmental Science; Earth Sciences; Economics and Management; Electronics; Energy Policy; Industrial and Production Engineering; Industrial Chemistry/Chemical Engineering; Isotropy; Logging; Mineral Resources; Shear; Signal to noise ratio; Telemetry; Transmitters; Wave data; Wave measurement; Waveforms; 各向异性; 声波测井技术; 油气勘探工作; 电子学
• ISSN: 1672-5107; 1995-8226
• DOI: 10.1007/s12182-008-0017-1

When entering an anisotropic formation, a shear wave splits into a fast wave and a slow wave. Based on the principle of four-component cross-dipole acoustic wave measurement, the anisotropy of HTI （Horizontal Transverse Isotropy） formation can be determined. The method of calculating the fast and slow wave data when a shear wave propagates along the borehole axis in anisotropic formation was analyzed, and the implementation of a cross-dipole acoustic logging tool was demonstrated. The tool was composed of transmitter electronics, transmitter mandrel, acoustic isolator, receiver mandrel and main control electronics. Sonde, transmitter circuit, signal receiving and processing circuit, data acquisition system, system control circuit and telemetry interface circuit were presented and analyzed. The test model was used in production wells and standard wells in various areas and the four-component cross-dipole waves were acquired and processed. The waves had good signal-to-noise ratio and clear characteristics, and the fast and slow waveforms, processed slowness curves, anisotropy and fast shear wave azimuth well matched with each other.