ACOUSTIC LOGGING TOOL AND CALIBRATION SYSTEM

Claims

1. An acoustic logging tool containing an acoustic transmitting array capable of transmitting modal waves with different energy levels and focusing combinations in the formation; a transmitting and receiving control device adjacent to the first end of the acoustic transmitting array and configured to determine a transmitting mode and provide the acoustic transmitting array with transmitting energy at a given level in accordance with the transmitting mode, thereby exciting certain transmitting units of the acoustic transmitting array; an acoustic receiving array that includes a first end adjacent to a second end of the acoustic transmitting array and is configured to receive acoustic signals from different azimuths; and a receiving and control device adjacent to the second end of the acoustic receiving array and configured to generate acoustic logging data based on the acoustic signals, wherein all modal wave transmission azimuths are offset from their receiving azimuths.

2. An acoustic logging tool according to claim 1, characterized in that the acoustic receiving array contains a plurality of acoustic receiving modules, wherein each acoustic receiving module contains a plurality of acoustic receiving units, wherein the acoustic receiving units of the same acoustic receiving module are distributed along the direction around the circumference of the tool body, and the reception azimuths of the acoustic receiving units in each acoustic receiving module are completely offset relative to each other.

3. The acoustic logging tool according to claim 2, characterized in that each acoustic receiving unit is connected to the tool body by means of movable levers, wherein the movable levers are designed to remain in an extended state during cable logging or logging on a drill pipe, such that the acoustic receiving units protrude to fit against the wall of the borehole, while being in a retracted state during logging while drilling, such that the acoustic receiving units are retracted into the tool body to form an insulating channel between the tool body and the wall of the borehole.

4. An acoustic logging tool according to paragraph 2 or 3, characterized in that the acoustic receiving units in different acoustic receiving modules are identical in number, while two acoustic receiving modules are located, each of which contains eight acoustic receiving units; or There are four acoustic receiving modules, each of which contains four acoustic receiving units.

5. An acoustic logging tool according to any one of paragraphs 2-4, characterized in that each of the acoustic receiving units contains an acoustic receiving transducer, a signal amplification circuit, a bandpass filter circuit and a wellbore diameter detector, wherein the acoustic receiving array additionally comprises an accelerometer located corresponding to each of the said acoustic receiving devices, wherein the receiving and control device comprises: a receiving and control module for receiving acoustic signals, borehole diameter measurement signals and acceleration signals received from the acoustic receiving array and modulating the signals to generate acoustic logging data; and A communication module for transmitting acoustic logging data to other borehole instruments or transmitting it to the earth's surface.

6. An acoustic logging tool according to any one of paragraphs 1-5, characterized in that the transmitting and receiving control device is further configured to generate transmission control signals based on the transmission mode, for controlling a given transmitting unit for generating an acoustic signal in a given excitation direction based on the transmission control signals, wherein the acoustic transmitting array comprises a near transmitter array adjacent to the first end of the acoustic receiver array for transmitting high frequency acoustic signals into the formation; and a far transmitting array adjacent to a near transmitting array for transmitting low-frequency acoustic signals into the formation.

7. The acoustic logging tool according to claim 6, characterized in that the near transmitting array comprises a high-frequency range acoustic transmitting module with a plurality of high-frequency transmitting units, wherein the high-frequency transmitting units form different source distances, in the range from near to far, from the acoustic receiving array, respectively; and the far transmitting array comprises a low-frequency acoustic transmitting module with a plurality of low-frequency transmitting units, wherein the low-frequency transmitting units form different source distances, in the range from near to far, from the acoustic receiving array, respectively, in this case, the transmission azimuths of all transmitting units are completely shifted relative to the reception azimuths of all acoustic receiving units in the acoustic receiving array.

8. The acoustic logging tool according to claim 7, characterized in that the near transmitting array comprises a first amplification circuit, which is configured to amplify the received transmit energy and supply the amplified voltage to the high-frequency acoustic transmitting module, wherein the high-frequency acoustic transmitting module comprises a first transmitting unit, a second transmitting unit and a third transmitting unit, which generate different source distances, in the range from near to far, from the acoustic receiving array, respectively;and the far transmitting array comprises a second amplification circuit, which is configured to amplify the received transmitting energy and supply the amplified voltage to the low-frequency range acoustic transmitting module, wherein the low-frequency range acoustic transmitting module comprises a fourth transmitting unit, a fifth transmitting unit and a sixth transmitting unit, which form different source distances, in the range from near to far, from the acoustic receiving array, respectively.

9. The acoustic logging tool of claim 8, wherein the first transmitter unit, the third transmitter unit, the fourth transmitter unit, and the sixth transmitter unit are all monopole transmitter transducers, wherein each monopole transmitter transducer comprises multiple piezoelectric elements spaced evenly along the circumferential direction of the tool body, and the transmission azimuths corresponding to all piezoelectric elements of all monopole transmitter transducers are completely offset from the reception azimuths corresponding to all acoustic receiving units in the acoustic receiving array.

10. An acoustic logging tool according to claim 8 or 9, characterized in that the second transmitting unit and the fifth transmitting unit are dipole transmitting transducers, wherein each dipole transmitting transducer comprises several piezoelectric elements uniformly spaced at intervals along the circumferential direction of the tool body, and the transmitting azimuths corresponding to all piezoelectric elements of all dipole transmitting transducers are completely offset from the receiving azimuths corresponding to all acoustic receiving units in the acoustic receiving array.

11. An acoustic logging tool according to any one of paragraphs 8-10, characterized in that the transmission frequency range of the first transmitting unit is 20~50 kHz; the transmission frequency range of the second transmitting unit is 1.2~8 kHz; the transmission frequency range of the third transmitting unit is 12~25 kHz; the transmission frequency range of the fourth transmitting unit is 5~15 kHz; the transmission frequency range of the fifth transmitting unit is 0.3~3.5 kHz; and The transmission frequency range of the sixth transmitting unit is 1~10 kHz.

12. An acoustic logging tool according to any one of paragraphs 1-11, characterized in that the transmission and reception control device comprises: a transmit and receive control sub-assembly that is coupled to the receive and receive control device and is configured to generate power supply combination commands based on the transmission mode; and a plurality of lower energy transfer units that are configured to, under the control of energy supply combination commands, connect to each other in predetermined combinations to generate a sufficient amount of transmission energy.

13. A calibration system for an acoustic logging tool, comprising cylinder; standard acoustic transmitter located at the first mark on the inner wall of the cylinder; a standard acoustic receiver located at the second mark on the inner wall of the cylinder; and an acoustic logging tool according to any one of paragraphs 1-12, which is located in the center of the cylinder such that a given transmitting unit and a given receiving unit of the acoustic logging tool are aligned with a standard acoustic receiver and a standard acoustic transmitter, respectively; a first control device configured to receive and record a first acoustic signal received by a standard acoustic receiver during a first test and to control a standard acoustic transmitter to transmit a second acoustic signal during a second test; a second control device configured to control a given transmitting unit to transmit a first acoustic signal in a first test, and to receive and record a second acoustic signal received by a given receiving unit in a second test; and a data analysis device configured to process the received acoustic signals in the first and second tests to obtain primary measurement data for calibrating a given transmitter unit and a given receiver unit in the acoustic logging tool.

14. The calibration system according to claim 13, characterized in that the calibration system further comprises a movement mechanism located on the acoustic logging device and configured to control the movement of the acoustic receiving units in the acoustic receiving array in such a way that one of the acoustic receiving units, corresponding to the azimuth to be measured, is aligned with the standard acoustic transmitter.

15. The calibration system according to claim 13 or 14, characterized in that the second control device is configured to control the fixed position of the acoustic logging tool, wherein, when the acoustic logging tool is located within the lower section of the cylinder, the second control device controls a specified transmitting unit within the acoustic transmitting array of the acoustic logging tool for transmitting a reference acoustic signal, which is configured to receive and record by acoustic receiving units within the acoustic receiving array of the acoustic logging tool, wherein the data analysis device is configured to perform calibration for the acoustic transmitting array and the acoustic receiving array by conducting a comparative analysis between the data of the main measurement and the data corresponding to the reference acoustic signal.

16. A calibration system according to any one of paragraphs 13-15, characterized in that the upper section of the cylinder is made of PPR, and its lower section is made of metal, while the lower part of the cylinder is sealed, its upper part is provided with a detachable metal plate, and the inside of the cylinder is filled with an acoustic coupling fluid.

17. A calibration system according to any one of paragraphs 13-16, characterized in that the first control device contains a receiving and communication module, which contains a signal receiving and generating circuit that is connected to a standard acoustic receiver and is configured to receive the first acoustic signal and filter it; a data acquisition circuit that is connected to the signal receiving and generating circuit and is configured to perform digitization of signals output from the signal receiving and generating circuit; and a communication interface circuit that is connected to the data receiving circuit and is configured to package the received digital data and transmit it to the data analysis device.

18. The calibration system according to paragraph 17, characterized in that the first control device additionally contains an acoustic transmitting module, which contains a transmission control circuit configured to generate transmission control excitation signals upon receipt of transmission commands sent by the data receiving circuit, wherein the transmission commands are sent by the data analysis device and transmitted to the data receiving circuit via the communication interface circuit; a constant voltage generating circuit configured to generate signals of a given voltage required for acoustic transmission; and a transmission excitation circuit configured to, under the control of the transmission control excitation signals, convert the specified voltage signals into a second acoustic signal and supply the second acoustic signal to a standard acoustic transmitter to be transmitted.