Ultrasonic transducer with reduced backing reflection

Patent metadata

Field	Value
Publication number	US-2021103069-A1
Application number	US-201816463689-A
Country	US
Kind code	A1
Filing date	Jun 27, 2018
Priority date	Jun 27, 2018
Publication date	Apr 8, 2021
Grant date	—

Abstract

A well tool can be used in a wellbore that can measure characteristics of an object in the wellbore. The well tool includes an ultrasonic transducer for generating an ultrasonic wave in a medium of the wellbore. The ultrasonic transducer includes a front layer, a rear layer, backing material coupled to the rear layer, and piezoelectric material coupled to the front layer and to the backing material. The rear layer can improve signal-to-noise ratio of the transducer in applications such as imaging and caliper applications.

First claim

What is claimed is:

1 . A well tool usable in a wellbore, the well tool comprising:
an ultrasonic transducer for generating an ultrasonic wave in a medium of the wellbore, the ultrasonic transducer comprising:
a front layer;
a rear layer;
backing material coupled to the rear layer; and
piezoelectric material coupled to the front layer and to the backing material.

2 . The well tool of claim 1 , wherein the rear layer is a rear quarter-wavelength plate.

3 . The well tool of claim 2 , wherein the front layer is a front quarter-wavelength plate.

4 . The well tool of claim 1 , wherein the ultrasonic transducer is an ultrasound ultrasonic transducer for outputting the ultrasonic wave at a frequency of 20 kHz or higher.

5 . The well tool of claim 1 , wherein the well tool comprises a logging-while-drilling tool or a wireline tool.

6 . The well tool of claim 1 , further comprising:
an ultrasonic sensor for detecting a reflection or a refraction of the ultrasonic wave off an object in the wellbore and transmitting an associated signal; a processing device in communication with the ultrasonic transducer and the ultrasonic sensor; and a memory device in which instructions are stored that are executable by the processing device for causing the processing device to:
receive the associated signal from the ultrasonic sensor; and
determine a characteristic of the object based on the associated signal.

7 . The well tool of claim 6 , wherein the characteristic is an image of the object.

8 . The well tool of claim 6 , wherein the characteristic is a measured diameter of part of the wellbore determined by a caliper application, an impedance of borehole material, or an existence of a deformity of a wall of the borehole wall.

9 . A sensor system for use in a wellbore, the sensor system comprising:
an ultrasonic transducer for generating an ultrasonic wave in a medium of the wellbore, the ultrasonic transducer comprising:
a front layer;
a rear layer;
backing material coupled to the rear layer; and
piezoelectric material coupled to the front layer and to the backing material;
a hydrophone for detecting a reflection or a refraction of the ultrasonic wave off an object in the wellbore and transmitting an associated signal to a processing device.

10 . The sensor system of claim 9 , wherein the rear layer is a rear quarter-wavelength plate and the front layer is a front quarter-wavelength plate.

11 . The sensor system of claim 9 , wherein the ultrasonic transducer is an ultrasound ultrasonic transducer for outputting the ultrasonic wave at a frequency of 20 kHz or higher.

12 . The sensor system of claim 9 , wherein the sensor system is in a logging-while-drilling tool or a wireline tool.

13 . The sensor system of claim 9 , further comprising:
the processing device in communication with the ultrasonic transducer and the hydrophone; and a memory device in which instructions are stored that are executable by the processing device for causing the processing device to:
receive the associated signal from the hydrophone; and
determine a characteristic of the object based on the associated signal.

14 . The sensor system of claim 13 , wherein the characteristic is an image of the object.

15 . The sensor system of claim 13 , wherein the characteristic is a measured diameter of part of the wellbore determined by a caliper application, an impedance of borehole material, or an existence of a deformity of a wall of the borehole wall.

16 . A method, comprising;
disposing a well tool in a wellbore, the well tool including a hydrophone and an ultrasonic transducer, the ultrasonic transducer including a front layer, a rear layer, backing material coupled to the rear layer, and piezoelectric material coupled to the front layer and to the backing material; outputting, by the ultrasonic transducer, an ultrasonic wave in a medium of the wellbore; detecting, by the hydrophone, a reflection or a refraction of the ultrasonic wave off an object in the wellbore; generating, by the hydrophone, a representative signal of the reflection or the refraction of the ultrasonic wave off the object in the wellbore; and using the representative signal to determine a characteristic of the object.

17 . The method of claim 16 , wherein the rear layer is a rear quarter-wavelength plate and the front layer is a front quarter-wavelength plate,
wherein the ultrasonic transducer is an ultrasound ultrasonic transducer for outputting the ultrasonic wave at a frequency of 20 kHz or higher.

18 . The method of claim 16 , wherein the well tool is a logging-while-drilling tool or a wireline tool.

19 . The method of claim 16 , wherein the characteristic is an image of the object.

20 . The method of claim 16 , wherein the characteristic is a measured diameter of part of the wellbore determined by a caliper application, an impedance of borehole material, or an existence of a deformity of a wall of the borehole wall.

Assignees

• Halliburton Energy Services Inc

Inventors

• Jin Jing
• Ge Yao
• Li Wei
• Wu Xiang

Classifications

• E21B47/0025

  generating an image of the borehole wall using down-hole measurements, e.g. acoustic or electric · CPC title

• G01N29/32 Primary

  Arrangements for suppressing undesired influences, e.g. temperature or pressure variations {, compensating for signal noise} · CPC title

• E21B47/08

  Measuring diameters or related dimensions at the borehole · CPC title

• G01V2200/16

  Measure-while-drilling or logging-while-drilling · CPC title

• G01N2291/02416

  Solids in liquids · CPC title