A high-density cross-hole elastic wave CT method and device

Abstract

The application discloses a high-density cross-hole elastic wave CT method and device, relates to the technical field of intelligent processing of engineering geological image results, measures the depth of two drill holes, determines a detection profile depth range and detection precision, determines the number and positions of exciting probes and receiving probes required for determining cross-hole seismic wave CT based on the detection profile depth range and the detection precision, and hangs the exciting probes on a plurality of exciting probe hanging positions of a first tethering rope.

Description

Technical Field

[0001] This invention relates to the field of intelligent processing technology for engineering geological image results, and in particular to a high-density trans-hole elastic wave CT method and apparatus. Background Technology

[0002] Cross-bore seismic CT technology utilizes the physical differences in the propagation of seismic waves in different media to perform imaging analysis of subsurface media. A signal source is excited between two or more boreholes, and then the seismic wave signals that have traveled through the subsurface media are received in other boreholes. Because different geological bodies (such as rocks, soils, cavities, fracture zones, etc.) have varying effects on the propagation speed and amplitude attenuation of seismic waves, by analyzing parameters such as the travel time (the time it takes for the seismic wave to travel from the excitation point to the receiving point) and amplitude of the received signals, and using specialized inversion algorithms, two-dimensional or three-dimensional images of the subsurface media between boreholes can be reconstructed, presenting the subsurface geological structure in a manner similar to how a CT scan in medicine reveals the internal structure of the human body.

[0003] The data acquisition process of the cross-hole seismic wave CT method is implemented as follows: using two boreholes that are not far apart, a signal source is excited at a certain depth in one borehole, and the signal propagating through the rock and soil medium between the boreholes is received at a certain depth in the other borehole. This obtains a pair of rays that penetrate the rock and soil between the boreholes. By moving the depth of the excitation probe and the receiving probe, different depth combinations are made to finally achieve complete coverage of the borehole profile by the ray pair.

[0004] Currently, data acquisition using trans-hole elastic wave CT methods is mostly done in a "one-transmit-one-receive" or "one-transmit-multiple-receive" mode, which requires manual adjustment of the height of the excitation or receiving probes. This can not only cause more human interference but also affect data acquisition efficiency.

[0005] The current technology has the drawback that there is only one excitation source. After collecting X-ray pairs at a certain depth, the height of the excitation source must be manually adjusted. This may cause inaccuracies in depth (affecting the quality of subsequent data processing) and also greatly reduces work efficiency. Summary of the Invention

[0006] To address the aforementioned technical problems, this invention provides a high-density trans-orifice elastic wave CT method and apparatus. The technical solution adopted is as follows:

[0007] A high-density trans-orifice elastic wave CT method includes the following steps:

[0008] Step 1: Measure the depth of the two boreholes to determine the depth range and accuracy of the detection profile. Based on the depth range and accuracy of the detection profile, determine the number and location of the excitation and receiving probes required for cross-hole seismic CT.

[0009] Step 2: Hang the number of excitation probes obtained in Step 1 on the multiple excitation probe mounting positions of the first tether rope, and hang the number of receiving probes obtained in Step 2 on the multiple receiving probe mounting positions of the second tether rope.

[0010] Step 3: By winding the first tether rope around the first fixed pulley and inserting the first tether rope carrying multiple excitation probes into the first borehole, the multiple excitation probes are positioned at the excitation probe positions obtained in Step 1, and then the first tether rope is fixed; by winding the second tether rope around the second fixed pulley and inserting the second tether rope carrying multiple receiving probes into the second borehole, the multiple receiving probes are positioned at the receiving probe positions obtained in Step 1, and then the second tether rope is fixed.

[0011] Step 4: Set the operating parameters of multiple excitation probes via computer, including initializing the serial numbers of multiple excitation probes, setting the excitation sequence, excitation energy, and interval time; set the operating parameters of multiple receiving probes, including initializing the serial numbers of receiving probes.

[0012] Step 5: Start data acquisition. The computer sends the operating parameters of multiple excitation probes and multiple receiving probes to the acquisition controller. The acquisition controller controls the multiple excitation probes and multiple receiving probes to perform data acquisition. Each time, one excitation probe is activated and its corresponding multiple receiving probes are used for acquisition. During the shutdown time, the acquired data is transmitted to the computer for storage. All excitation probes and their corresponding receiving probes are activated in sequence until all X-ray pairs of the profile under test are acquired.

[0013] By adopting the above technical solution, the excitation probes can generate seismic waves, which are connected to each other by a first tether rope and communicate with the acquisition controller and computer via a communication cable or wirelessly. The receiving probes can receive seismic waves from the excitation probes, which are connected to each other by a second tether rope and communicate with the acquisition controller and computer via a communication cable or wirelessly.

[0014] In practice, based on the borehole depth and required detection accuracy (for the same depth, the more probes and the shorter the connecting cables, the higher the detection accuracy), a corresponding number of small excitation probes and small receiving probes are selected and connected to the control host and computer via connecting and communication cables. The length of the communication cables is adjusted so that the small excitation probes and small receiving probes are evenly distributed within the corresponding borehole depth range of the section to be detected. Then, the operating parameters of the excitation probes are set through computer software, including initializing the sequence number of the small excitation probes, setting the excitation sequence, excitation energy, and interval time. The operating parameters of the receiving probes also need to be set, including initializing the sequence number of the small receiving probes, setting the filter, and synchronizing the probe clock. After completing the above computer settings, data acquisition begins. The computer sends the acquisition parameters to the acquisition controller, and the control host controls the excitation probes and receiving probes to perform data acquisition according to the corresponding parameters. Each time, one excitation probe and its corresponding multiple receiving probes are activated to acquire data, and the data is transmitted to the computer for storage via connecting and communication cables during the off-time. All excitation probes and their corresponding receiving probes are activated sequentially until all X-ray pairs of the section to be measured have been acquired.

[0015] Compared to the currently used seismic wave CT technology, it has higher data acquisition efficiency and fewer human interference factors.

[0016] Optionally, in step 1, the formula for determining the number of excitation probes and receiving probes is:

[0017] ;

[0018] in It refers to the number of excitation probes. It refers to the number of receiving probes. It is the depth of the first and second boreholes. It refers to the detection accuracy, which is determined based on the probe spacing.

[0019] Optionally, the method for determining the positions of the excitation probe and the receiving probe is as follows: the distance between the bottommost excitation probe and the bottom of the first borehole is the detection accuracy. Based on the order of the excitation probes, an excitation probe is arranged upwards at intervals of detection accuracy. The method for determining the position of the receiving probe is the same as the method for determining the position of the excitation probe.

[0020] Optionally, in step 3, the method for determining the distance between the bottommost excitation probe and the bottom of the first borehole is as follows: a wireless laser rangefinder is installed at the bottom of the bottommost excitation probe, with the sensor head of the wireless laser rangefinder pointing vertically downwards. When the first tethering rope is placed into the first borehole, the distance between the bottommost excitation probe and the bottom of the first borehole is determined by receiving the ranging result emitted by the wireless laser rangefinder.

[0021] By adopting the above technical solution, and by installing a wireless laser rangefinder at the bottom of the bottom excitation probe, the distance between the bottom excitation probe and the bottom of the first borehole can be determined by receiving the rangefinder result emitted by the wireless laser rangefinder during the slow lowering of the first tether rope. This allows for precise placement of the excitation probe and improves the accuracy of CT results.

[0022] A high-density trans-orifice elastography (TEE) device is provided for implementing a high-density TEE method. The device includes multiple excitation probes, multiple receiving probes, a first tether rope, a second tether rope, a first fixed pulley, a second fixed pulley, a computer, and a chip-based acquisition controller. The first tether rope has multiple excitation probe mounting positions, and the second tether rope has multiple receiving probe mounting positions. The multiple excitation probes are respectively installed in the multiple excitation probe mounting positions, and the multiple receiving probes are respectively installed in the multiple receiving probe mounting positions. The first fixed pulley is installed on one side of the borehole opening of a first borehole, and the second fixed pulley is installed on one side of the borehole opening of a second borehole. The first tether rope is wound around the first fixed pulley, and the first tether rope carrying the multiple excitation probes is placed into the first borehole. The second tether rope is wound around the second fixed pulley, and the second tether rope carrying the multiple receiving probes is placed into the second borehole. After the multiple receiving probes are positioned at the receiving probe positions obtained in step 1, the second tether rope is fixed. The multiple excitation probes and multiple receiving probes are respectively communicatively connected to the computer. The computer is communicatively connected to the acquisition controller, and the acquisition controller controls the execution actions of the multiple excitation probes and multiple receiving probes.

[0023] Optionally, it also includes a pair of bottom probe position determination devices, one of which is used to determine the distance between the bottommost excitation probe of the first tether rope and the bottom of the first borehole, and the other of which is used to determine the distance between the bottommost receiving probe of the second tether rope and the bottom of the second borehole.

[0024] Optionally, the bottom probe position determination device includes a wireless laser rangefinder sensor, a wireless transceiver module, and a display. The wireless laser rangefinder sensor is installed on the housing of the bottom excitation probe or receiving probe, with the sensor head of the wireless laser rangefinder sensor pointing vertically downwards. The display is installed on the side of the opening of the first and second drill holes, and the display is communicatively connected to the wireless laser rangefinder sensor through the wireless transceiver module.

[0025] By adopting the above technical solution, and by installing a wireless laser rangefinder at the bottom of the bottom excitation probe (or, alternatively, at the bottom of the tether rope), the distance between the bottom excitation probe and the bottom of the first borehole can be determined by receiving the ranging results emitted by the wireless laser rangefinder during the slow lowering of the first tether rope. When analyzing the distance between the excitation probe and the bottom of the first borehole, the distance between the wireless laser rangefinder and the bottom excitation probe needs to be considered, which can achieve precise placement of the excitation probe and improve the accuracy of CT results.

[0026] Optionally, multiple excitation probes and multiple receiving probes can be connected to a computer via communication cables or wireless communication.

[0027] Optionally, the acquisition controller includes a buffer and a control chip. The buffer is communicatively connected to a computer, and the control chip is communicatively connected to the buffer, and controls the execution actions of multiple excitation probes and multiple receiving probes respectively.

[0028] Optionally, the control chip is connected to multiple excitation probes and multiple receiving probes via communication cables or wireless communication.

[0029] By adopting the above technical solutions, wireless communication is usually used to reduce wiring difficulty. Wireless communication can be based on 4G, 5G and other technologies, or it can be based on LoRa wireless communication technology.

[0030] In summary, the present invention has at least one of the following beneficial technical effects:

[0031] This invention provides a high-density trans-hole elastic wave CT method and device, which is designed with multiple excitation probes and receiving probes. Any number of probes can be connected to each other and combined into a series. Correspondingly, there are also multiple receiving probes, which also have the feature of being connected to each other and combined into a series. In actual work, an appropriate number of probes can be selected to work together according to the borehole depth or the location of the target detection area to achieve efficient data acquisition, while reducing human interference factors. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of the structure of a high-density trans-hole elastic wave CT device according to the present invention;

[0033] Figure 2 This is a schematic diagram of the electrical component connection principle of a high-density trans-hole elastic wave CT device according to the present invention.

[0034] Explanation of reference numerals in the attached diagram: 1. Excitation probe; 2. Receiving probe; 3. First tether rope; 4. Second tether rope; 5. First fixed pulley; 6. Second fixed pulley; 71. Wireless laser rangefinder; 72. Wireless transceiver module; 73. Display; 100. First borehole; 101. Second borehole; 102. Computer; 103. Acquisition controller; 1031. Buffer; 1032. Control chip. Detailed Implementation

[0035] The present invention will be further described in detail below with reference to the accompanying drawings.

[0036] This invention discloses a high-density trans-hole elastic wave CT method and apparatus.

[0037] Reference Figure 1 and Figure 2 Example 1: A high-density trans-aperture elastic wave CT method includes the following steps:

[0038] Step 1: Measure the depth of the two boreholes to determine the depth range and accuracy of the detection profile. Based on the depth range and accuracy of the detection profile, determine the number and location of the excitation probe 1 and the receiving probe 2 required for cross-hole seismic CT.

[0039] Step 2: Hang the number of excitation probes 1 obtained in Step 1 on the multiple excitation probe mounting positions of the first tethering rope 3 respectively, and hang the number of receiving probes 2 obtained in Step 2 on the multiple receiving probe mounting positions of the second tethering rope 4 respectively.

[0040] Step 3: By winding the first tether rope 3 around the first fixed pulley 5 and inserting the first tether rope 3 carrying multiple excitation probes 1 into the first borehole 100, the first tether rope 3 is fixed after the multiple excitation probes 1 are positioned at the excitation probe positions obtained in Step 1; by winding the second tether rope 4 around the second fixed pulley 6 and inserting the second tether rope 4 carrying multiple receiving probes 2 into the second borehole 101, the second tether rope 4 is fixed after the multiple receiving probes 2 are positioned at the receiving probe positions obtained in Step 1.

[0041] Step 4: Set the operating parameters of multiple excitation probes 1 through computer 102, including initializing the serial numbers of multiple excitation probes 1, setting the excitation sequence, excitation energy magnitude and interval time; set the operating parameters of multiple receiving probes 2, including initializing the serial numbers of receiving probes 2.

[0042] Step 5: Start data acquisition. Computer 102 sends the operating parameters of multiple excitation probes 1 and multiple receiving probes 2 to acquisition controller 103. Acquisition controller 103 controls the multiple excitation probes 1 and multiple receiving probes 2 to perform data acquisition. Each time, one excitation probe 1 and its corresponding multiple receiving probes are activated to acquire data, and the acquired data is transmitted to computer 102 for storage during the off time. All excitation probes 1 and their corresponding receiving probes 2 are activated in sequence until all X-ray pairs of the profile under test are acquired.

[0043] The excitation probe 1 can generate seismic waves and is connected to each other by the first tether rope 3. It communicates with the acquisition controller 103 and the computer 102 via a communication cable or wirelessly. The receiving probe 2 can receive seismic waves from the excitation probe 1 and is connected to each other by the second tether rope 4. It communicates with the acquisition controller 103 and the computer 102 via a communication cable or wirelessly.

[0044] In practical work, first, based on the drilling depth and the required detection accuracy (for the same depth, the more probes and the shorter the connecting cables, the higher the detection accuracy), select the corresponding number of small excitation probes and small receiving probes. Connect them to the control host and computer via connecting cables and communication cables. Adjust the length of the communication cables so that the small excitation probes and small receiving probes are evenly distributed within the corresponding borehole depth range of the profile to be detected. Then, use the computer 102 software to set the working parameters of excitation probe 1, including initializing the sequence number of the small excitation probes, setting the excitation sequence, excitation energy, and interval time, etc. The receiving probes also need to be set... The operating parameters of the receiving probe 2 are initialized, including the serial number of the small receiving probe, the filter and the synchronization probe clock. After the computer 102 completes the above settings, data acquisition begins. The computer 102 sends the acquisition parameters to the acquisition controller 103. The control host controls the excitation probe 1 and the receiving probe 2 to perform data acquisition according to the corresponding parameters. Each time, one excitation probe 1 and multiple corresponding receiving probes 2 are activated to acquire data. During the off time, the data is transmitted to the computer for storage through the connection cable and the communication cable. All excitation probes 1 and corresponding receiving probes 2 are activated in sequence until all X-ray pairs of the section to be measured are acquired.

[0045] Compared to the currently used seismic wave CT technology, it has higher data acquisition efficiency and fewer human interference factors.

[0046] In Example 2, step 1, the formula for determining the number of excitation probe 1 and receiving probe 2 is:

[0047] ;

[0048] in It is the number of excitation probes 1. This refers to the number of receiving probes 2. It is the depth of the first borehole 100 and the second borehole 101. It refers to the detection accuracy, which is determined based on the probe spacing.

[0049] In Example 3, the method for determining the positions of the excitation probe 1 and the receiving probe 2 is as follows: the distance between the excitation probe 1 located at the bottom and the bottom of the first borehole 100 is the detection accuracy. Based on the sequence of the excitation probes 1, one excitation probe 1 is arranged upwards at every detection accuracy distance. The method for determining the position of the receiving probe 2 is the same as the method for determining the position of the excitation probe 1.

[0050] In Example 4, step 3, the method for determining the distance between the bottommost excitation probe 1 and the bottom of the first borehole 100 is as follows: a wireless laser rangefinder 71 is installed at the bottom of the bottommost excitation probe 1, with the sensor head of the wireless laser rangefinder 71 pointing vertically downwards. When the first tethering rope 3 is placed into the first borehole 100, the distance between the bottommost excitation probe 1 and the bottom of the first borehole 100 is determined by receiving the ranging result emitted by the wireless laser rangefinder 71.

[0051] By installing a wireless laser rangefinder 71 at the bottom of the bottom excitation probe 1, the distance between the bottom excitation probe 1 and the bottom of the first borehole 100 can be determined by receiving the ranging result emitted by the wireless laser rangefinder 71 during the slow lowering of the first tether rope 3. This allows for precise placement of the excitation probe 1 and improves the accuracy of CT results.

[0052] Example 5: A high-density trans-hole elastography CT device for implementing a high-density trans-hole elastography CT method. The device includes multiple excitation probes 1, multiple receiving probes 2, a first tether rope 3, a second tether rope 4, a first fixed pulley 5, a second fixed pulley 6, a computer 102, and a chip-based acquisition controller 103. The first tether rope 3 has multiple excitation probe mounting positions, and the second tether rope 4 has multiple receiving probe mounting positions. The multiple excitation probes 1 are respectively installed in the multiple excitation probe mounting positions, and the multiple receiving probes 2 are respectively installed in the multiple receiving probe mounting positions. The first fixed pulley 5 is installed on one side of the borehole 100, and the second fixed pulley 6 is installed on... On one side of the opening of the second borehole 101, the first tether rope 3 is wound around the first fixed pulley 5, and the first tether rope 3 carrying multiple excitation probes 1 is placed into the first borehole 100. The second tether rope 4 is wound around the second fixed pulley 6, and the second tether rope 4 carrying multiple receiving probes 2 is placed into the second borehole 101. After the multiple receiving probes 2 are positioned at the receiving probe positions obtained in step 1, the second tether rope 4 is fixed. The multiple excitation probes 1 and the multiple receiving probes 2 are respectively connected to the computer 102 for communication. The computer 102 is connected to the acquisition controller 103 for communication. The acquisition controller 103 controls the execution actions of the multiple excitation probes 1 and the multiple receiving probes 2 respectively.

[0053] Example 6 further includes a pair of bottom probe position determination devices. One bottom probe position determination device is used to determine the distance between the bottommost excitation probe 1 of the first tether rope 3 and the bottom of the first borehole 100, and the other bottom probe position determination device is used to determine the distance between the bottommost receiving probe 2 of the second tether rope 4 and the bottom of the second borehole 101.

[0054] Example 7: The bottom probe position determination device includes a wireless laser rangefinder 71, a wireless transceiver module 72, and a display 73. The wireless laser rangefinder 71 is installed on the housing of the bottommost excitation probe 1 or receiving probe 2, with the sensing head of the wireless laser rangefinder 71 pointing vertically downwards. The display 73 is installed on the side of the opening of the first drill hole 100 and the second drill hole 101. The display 73 is communicatively connected to the wireless laser rangefinder 71 through the wireless transceiver module 72.

[0055] By installing a wireless laser rangefinder 71 at the bottom of the bottommost excitation probe 1 (or at the bottom of the tether rope), the distance between the bottommost excitation probe 1 and the bottom of the first borehole 100 can be determined by receiving the ranging result emitted by the wireless laser rangefinder 71 during the slow lowering of the first tether rope 3. When analyzing the distance between the excitation probe 1 and the bottom of the first borehole 100, the distance between the wireless laser rangefinder 71 and the bottommost excitation probe 1 needs to be considered, which can achieve precise placement of the excitation probe 1 and improve the accuracy of CT results.

[0056] In Example 8, multiple excitation probes 1 and multiple receiving probes 2 are respectively connected to computer 102 via communication cables or wireless communication.

[0057] Example 9: The acquisition controller 103 includes a buffer 1031 and a control chip 1032. The buffer 1031 is communicatively connected to the computer 102, and the control chip 1032 is communicatively connected to the buffer 1031, and controls the execution actions of multiple excitation probes 1 and multiple receiving probes 2 respectively.

[0058] In Example 10, the control chip 1032 is connected to multiple excitation probes 1 and multiple receiving probes 2 via communication cables or wireless communication.

[0059] To reduce wiring complexity, wireless communication is typically used. Wireless communication can be based on technologies such as 4G and 5G, or it can be based on LoRa wireless communication technology.

[0060] The above are all preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Therefore, all equivalent changes made in accordance with the structure, shape and principle of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A high-density trans-orifice elastic wave CT method, characterized in that, Includes the following steps: Step 1: Measure the depth of the two boreholes to determine the depth range and accuracy of the detection profile. Based on the depth range and accuracy of the detection profile, determine the number and location of the excitation probe (1) and receiving probe (2) required for cross-hole seismic CT. Step 2: Hang the number of excitation probes (1) obtained in Step 1 on the multiple excitation probe mounting positions of the first tether rope (3), and hang the number of receiving probes (2) obtained in Step 2 on the multiple receiving probe mounting positions of the second tether rope (4). Step 3: By winding the first tether rope (3) around the first fixed pulley (5) and inserting the first tether rope (3) carrying multiple excitation probes (1) into the first borehole (100), the first tether rope (3) is fixed after the multiple excitation probes (1) are located at the excitation probe position obtained in Step 1; by winding the second tether rope (4) around the second fixed pulley (6) and inserting the second tether rope (4) carrying multiple receiving probes (2) into the second borehole (101), the second tether rope (4) is fixed after the multiple receiving probes (2) are located at the receiving probe position obtained in Step 1. Step 4: Set the working parameters of multiple excitation probes (1) through computer (102), including initializing the serial numbers of multiple excitation probes (1), setting the excitation sequence, excitation energy magnitude and intermittent time; set the working parameters of multiple receiving probes (2), including initializing the serial numbers of receiving probes (2); Step 5: Start data acquisition. The computer (102) sends the working parameters of the multiple excitation probes (1) and multiple receiving probes (2) to the acquisition controller (103). The acquisition controller (103) controls the multiple excitation probes (1) and multiple receiving probes (2) to perform data acquisition. Each time, one excitation probe (1) and the corresponding multiple receiving probes (2) are activated to perform acquisition. The acquired data is transmitted to the computer (102) for storage during the off time. All excitation probes (1) and corresponding receiving probes (2) are activated in sequence until all X-ray pairs of the profile to be measured are acquired. In step 1, the formula for determining the number of excitation probes (1) and receiving probes (2) is: ； in It is the number of excitation probes (1). It is the number of receiving probes (2). It is the depth of the first borehole (100) and the second borehole (101). It refers to the detection accuracy, which is determined based on the probe spacing. The method for determining the positions of the excitation probe (1) and the receiving probe (2) is as follows: the distance between the excitation probe (1) at the bottom and the bottom of the first borehole (100) is the detection accuracy. Based on the order of the excitation probes (1), an excitation probe (1) is arranged upwards at every detection accuracy distance. The method for determining the position of the receiving probe (2) is the same as the method for determining the position of the excitation probe (1). In step 3, the method for determining the distance between the bottommost excitation probe (1) and the bottom of the first borehole (100) is as follows: a wireless laser rangefinder (71) is installed at the bottom of the bottommost excitation probe (1). The sensor head of the wireless laser rangefinder (71) is vertically downward. When the first tether rope (3) is placed into the first borehole (100), the distance between the bottommost excitation probe (1) and the bottom of the first borehole (100) is determined by receiving the ranging result transmitted by the wireless laser rangefinder (71). A high-density trans-hole elastic wave CT method is implemented using a high-density trans-hole elastic wave CT device. The device includes multiple excitation probes (1), multiple receiving probes (2), a first tether rope (3), a second tether rope (4), a first fixed pulley (5), a second fixed pulley (6), a computer (102), and a chip-based acquisition controller (103). The first tether rope (3) has multiple excitation probe mounting positions, and the second tether rope (4) has multiple receiving probe mounting positions. The multiple excitation probes (1) are respectively installed in the multiple excitation probe mounting positions, and the multiple receiving probes (2) are respectively installed in the multiple receiving probe mounting positions. The first fixed pulley (5) is installed on one side of the opening of the first borehole (100), and the second fixed pulley (6) is installed in the second borehole (100). 1) On one side of the orifice, the first tether rope (3) is wrapped around the first fixed pulley (5), and the first tether rope (3) carrying multiple excitation probes (1) is placed into the first borehole (100). The second tether rope (4) is wrapped around the second fixed pulley (6), and the second tether rope (4) carrying multiple receiving probes (2) is placed into the second borehole (101). After the multiple receiving probes (2) are located at the receiving probe positions obtained in step 1, the second tether rope (4) is fixed. The multiple excitation probes (1) and the multiple receiving probes (2) are respectively connected to the computer (102). The computer (102) is connected to the acquisition controller (103). The acquisition controller (103) controls the execution actions of the multiple excitation probes (1) and the multiple receiving probes (2).

2. The high-density trans-aperture elastic wave CT method according to claim 1, characterized in that, It also includes a pair of bottom probe position determination devices, one of which is used to determine the distance between the bottom excitation probe (1) of the first mooring rope (3) and the bottom of the first borehole (100), and the other of which is used to determine the distance between the bottom receiving probe (2) of the second mooring rope (4) and the bottom of the second borehole (101).

3. The high-density trans-orifice elastic wave CT method according to claim 2, characterized in that: The bottom probe position determination device includes a wireless laser rangefinder (71), a wireless transceiver module (72), and a display (73). The wireless laser rangefinder (71) is installed on the housing of the bottom excitation probe (1) or receiving probe (2). The sensing head of the wireless laser rangefinder (71) is vertically downward. The display (73) is installed on the side of the opening of the first borehole (100) and the second borehole (101). The display (73) is connected to the wireless laser rangefinder (71) through the wireless transceiver module (72).

4. The high-density trans-orifice elastic wave CT method according to claim 3, characterized in that: Multiple excitation probes (1) and multiple receiving probes (2) are connected to the computer (102) via communication cables or wireless communication.

5. The high-density trans-orifice elastic wave CT method according to claim 4, characterized in that: The acquisition controller (103) includes a buffer (1031) and a control chip (1032). The buffer (1031) is connected to a computer (102) and the control chip (1032) is connected to the buffer (1031) and controls the execution actions of multiple excitation probes (1) and multiple receiving probes (2) respectively.

6. The high-density trans-orifice elastic wave CT method according to claim 5, characterized in that: The control chip (1032) is connected to multiple excitation probes (1) and multiple receiving probes (2) via communication cables or wireless communication.

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