Title
Acoustic Emission and Echo Signal Compensation Techniques Applied to an Ultrasonic Logging-While-Drilling Caliper.
Abstract
A logging-while-drilling (LWD) caliper is a tool used for the real-time measurement of a borehole diameter in oil drilling engineering. This study introduces the mechanical structure and working principle of a new LWD caliper based on ultrasonic distance measurement (UDM). The detection range is a major performance index of a UDM system. This index is determined by the blind zone length and remote reflecting interface detection capability of the system. To reduce the blind zone length and detect near the reflecting interface, a full bridge acoustic emission technique based on bootstrap gate driver (BGD) and metal-oxide-semiconductor field effect transistor (MOSFET) is designed by analyzing the working principle and impedance characteristics of a given piezoelectric transducer. To detect the remote reflecting interface and reduce the dynamic range of the received echo signals, the relationships between the echo amplitude and propagation distance of ultrasonic waves are determined. A signal compensation technique based on time-varying amplification theory, which can automatically change the gain according to the echo arrival time is designed. Lastly, the aforementioned techniques and corresponding circuits are experimentally verified. Results show that the blind zone length in the UDM system of the LWD caliper is significantly reduced and the capability to detect the remote reflecting interface is considerably improved.
Year
DOI
Venue
2017
10.3390/s17061351
SENSORS
Keywords
Field
DocType
logging-while-drilling caliper,ultrasonic distance measurement,piezoelectric transducer,blind zone elimination,time-varying amplification
Calipers,Ultrasonic sensor,Dynamic range,Electronic engineering,Electrical impedance,Engineering,Acoustics,Electronic circuit,Logging while drilling,Acoustic emission,Gate driver
Journal
Volume
Issue
ISSN
17
6
1424-8220
Citations 
PageRank 
References 
1
0.41
1
Authors
4
Name
Order
Citations
PageRank
Yongchao Yao110.41
Xiao-dong Ju211.09
Jun-qiang Lu310.41
Bai-yong Men411.09