Experimental study on the performance of an azimuthal acoustic receiver sonde for a downhole tool. (23rd May 2016)

• Record Type: Journal Article
• Authors: Che, Xiaohua; Qiao, Wenxiao; Ju, Xiaodong; Wu, Jinping; Men, Baiyong
• Is Part Of: Geophysical prospecting. Volume 65:Number 1(2017)
• Page Start: 158
• Page End: 169
• Publication Date: 2016-05-23
• Subjects: Acoustic -- Logging -- Full waveform -- Parameter estimation; Prospecting -- Geophysical methods -- Periodicals; 622.15
• DOI: 10.1111/1365-2478.12401
• Languages: English
• ISSNs: 0016-8025

Abstract

ABSTRACT: A new azimuthal acoustic receiver sonde with a body and corresponding circuits was designed for a downhole tool. The 64‐sensor receiver sonde holds eight receiver stations that can be combined into at least 64 three‐sensor receiver subarrays. As a result, the receiver sonde can use different sensor combinations instead of different transducer types to produce multiple modes, including a phased azimuthal reception mode and conventional monopole, dipole, and quadruple modes. Laboratory measurements were conducted to study the performance of the azimuthal acoustic receiver sonde for a downhole tool, and the experimental results indicate that the receiver sonde provides a consistent reception performance. Individual sensors receive similar time‐domain waveforms, and their corresponding frequency bands and sensitivities are consistent within the measurement errors of around 5%. The direction of the reception main lobe is approximately parallel to its exterior normal direction. In addition, a receiver subarray with three sensors receives waveforms that have higher energy and narrower beamwidths. For individual sensors, the angular width of the dominant reception lobe is 191.3 ° on average, whereas that of the individual receiver subarrays is approximately 52.1 ° on average. The amplitude of the first arrival received by the receiver subarray centred at the primary sensor directly pointing to the source is approximately 2.2 times the average amplitude of the first arrivals received by the other receiver subarrays in the same receiver station. Thus, the maximum amplitude of the waveforms received by the receiver subarrays can be used to determine the direction of the incident waves. This approach represents a promising method for determining the reflector azimuth for acoustic reflection logging and three‐dimensional acoustic logging.