Calibration of Ultrasonic Transducer Based on Ultrasonic Logging Instrument for Shaft Sinking

Area of Science:

• Geophysics
• Mechanical Engineering
• Materials Science

Background:

• High-precision logging equipment is essential for accurate borehole diameter and drilling offset measurements in coal and petroleum industries.
• The performance of logging systems, particularly logging distance, relies heavily on the self-reception sensitivity and error characteristics of downhole ultrasonic transducers.

Purpose of the Study:

• To propose a module composition and positioning principle for ultrasonic transducers within an Ultrasonic Logging Instrument for Shaft Sinking by Drilling (ULISSD).
• To develop and validate an ultrasonic-transducer error-calibration device and method to enhance measurement accuracy in central-air-return-shaft drilling projects.

Main Methods:

• Developed a novel ultrasonic-transducer error-calibration device to measure errors between the piezoelectric element and the borehole logging system's rubber seal.
• Implemented a calibration method specifically for central-air-return-shaft drilling applications.
• Calculated the rate of propagation with high accuracy by eliminating inherent transducer errors.

Main Results:

• The developed calibration device effectively eliminates inherent transducer errors.
• The measurement error was reduced by approximately 1.5 mm.
• The accuracy of the Ultrasonic Logging Instrument for Shaft Sinking by Drilling (ULISSD) was effectively improved for central-air-return-shaft drilling.

Conclusions:

• The proposed module composition and positioning principle for ultrasonic transducers are effective for calculating reflection distance.
• The developed error-calibration device and method significantly enhance the precision of ultrasonic logging instruments.
• The findings demonstrate a practical solution for improving borehole measurement accuracy in critical drilling operations.