Optical fiber sensing sound wave detector supporting multidirectional detection based on elastic rod body

Abstract

The invention relates to the field of geophysical logging, and discloses an optical fiber sensing sound wave detector supporting multidirectional detection based on an elastic rod body and a detection device. An optical fiber sensing sound wave detector supporting multidirectional detection based on an elastic rod body comprises the elastic rod body and a plurality of optical fibers. Wherein a plurality of through holes are formed in the elastic rod body in the axis direction of the elastic rod body, the number of the through holes is the same as that of the optical fibers, and the through holes are formed in the periphery of the axis of the elastic rod body in an equal central angle mode; each optical fiber penetrates through a through hole formed in the axis direction of the elastic rod body and extends into the elastic rod body, and each through hole allows one optical fiber to penetrate through. The distributed optical fibers are used for receiving acoustic signals, the defect that the piezoelectric coefficient and the energy conversion efficiency of a traditional piezoelectric crystal are reduced in a high-temperature environment due to the fact that the traditional piezoelectric crystal is influenced by the Curie temperature of a ceramic material is overcome, and the problem that the amplitude of a receiver is saturated due to high-energy emission can also be avoided.

Description

Technical Field

[0001] This disclosure relates to the field of geophysical logging technology, and in particular to a fiber optic sensing acoustic detector based on an elastic rod supporting multi-directional detection. Background Technology

[0002] Sonic logging is a logging method that utilizes the acoustic properties of sound waves propagating through different rocks to study drilling geological profiles and assess cementing quality. Its principle involves placing a controlled acoustic source into the well. The sound waves emitted by the source cause vibrations in surrounding particles, generating volume waves (such as P-waves and S-waves) in the formation and induced interface waves (such as pseudo Rayleigh waves and Stoneley waves) at the drilling fluid interface on the wellbore. These waves, acting as carriers of formation information, are received by downhole receivers and transmitted to the surface for recording and analysis.

[0003] Sonic logging technology can be further divided into sonic velocity logging and sonic amplitude logging, depending on the parameters recorded. Sonic velocity logging mainly measures the speed at which sound waves propagate in rock formations, i.e., the time difference of formation slip waves, which is then used for formation evaluation, porosity and saturation estimation, and rock mechanical parameter assessment. Sonic amplitude logging, on the other hand, mainly records the changes in the amplitude of sound waves, which is used to study the absorption characteristics of formations and the physical properties of rocks.

[0004] Currently, with the increasing depth of oil and gas exploration target layers and the growing number of wells drilled, as well as the increasing number of high-temperature, ultra-deep, and small-bore well structures, these traditional acoustic logging tools that mainly rely on piezoelectric ceramic materials have brought many challenges. In particular, arrayed, multi-directional acoustic receiving systems and multi-channel receiving and acquisition circuit sections are limited by well size and extreme environmental conditions such as high temperature and high pressure, resulting in poor adaptability of these instruments under existing technologies and an inability to maintain stable long-term operation. Summary of the Invention

[0005] The purpose of this invention is to provide at least one fiber optic sensing acoustic wave detector, fiber optic sensing acoustic wave detection device, fiber optic sensing acoustic wave detection system, fiber optic sensing acoustic wave detection method, and computer program product based on an elastic rod supporting multi-directional detection. By employing multiple circumferentially uniformly arranged optical fibers, directional acoustic wave detection can be achieved. Compared with traditional acoustic logging instruments, this device eliminates the complex downhole acquisition circuitry, resulting in high system stability and reliability.

[0006] To address the aforementioned technical problems, at least one embodiment of this application provides a fiber optic sensing acoustic detector based on an elastic rod supporting multi-directional detection, comprising an elastic rod and multiple optical fibers; wherein:

[0007] Multiple through holes are provided inside the elastic rod along the axis of the elastic rod. The number of through holes is the same as the number of optical fibers, and the multiple through holes are arranged around the axis of the elastic rod with equal central angles.

[0008] Each optical fiber passes through a through hole arranged along the axis of the elastic rod and extends into the interior of the elastic rod, with each through hole allowing one optical fiber to pass through.

[0009] At least one embodiment of this application also provides an optical fiber sensing acoustic wave detection device, comprising:

[0010] The main body of the fiber optic sensing acoustic wave detection device;

[0011] The remote transmission module is located inside the fiber optic sensing acoustic wave detection device and is used to receive external transmission commands. The transmission commands are used to control the transmission line to provide transmission drive signals to the transmitting acoustic system.

[0012] The transmitting line is located inside the fiber optic sensing acoustic wave detection device and connected to the remote transmission module, and is used to provide a transmission drive signal to the transmitting acoustic system in response to the transmission command.

[0013] The transmitting acoustic system is located inside the fiber optic sensing acoustic wave detection device and connected to the transmitting line. It is used to amplify the transmitting drive signal provided by the transmitting line and perform the operation of exciting acoustic waves.

[0014] A sound insulation body is disposed between the transmitting sound system and the receiving sound system to block the direct wave excited by the transmitting sound system and propagating along the outer shell of the fiber optic sensing acoustic wave detection device.

[0015] The receiving acoustic system is located inside the main body of the fiber optic sensing acoustic wave detection device. It is used to conduct externally emitted laser pulse signals and to enhance the sensitivity of weak acoustic signals from the outside to cause disturbance in the optical fiber located inside the receiving acoustic system, thereby coupling the mechanical vibration caused by the weak acoustic signal into the scattered light signal of the laser pulse signal.

[0016] The receiving acoustic system includes a fiber optic sensing acoustic detector, as described above, which supports multi-directional detection based on an elastic rod.

[0017] At least one embodiment of this application also provides an optical fiber sensing acoustic wave detection system, comprising:

[0018] As described above, fiber optic sensing acoustic wave detection device;

[0019] The control system is connected to the remote transmission module of the fiber optic acoustic wave detection device and is used to control the transmitting acoustic system of the fiber optic acoustic wave detection device to perform the operation of exciting acoustic waves, to perform the operation of emitting laser pulses to the fiber optic acoustic wave detection device, and to generate acoustic logging data based on the scattered light signal of the laser pulse signal collected by the fiber optic acoustic wave detection device.

[0020] At least one embodiment of this application also provides a fiber optic sensing acoustic wave detection method, based on the system described above, the method comprising:

[0021] Determine the current well depth at which the fiber optic sensing acoustic detection device is located in the well to be tested;

[0022] A transmission command is sent to the fiber optic sensing acoustic wave detection device to control the transmitting acoustic system of the fiber optic sensing acoustic wave detection device to perform an excitation acoustic wave operation and acquire the scattered light signal coupled with the mechanical vibration caused by the acoustic wave, collected by each optical fiber in the receiving acoustic system; wherein, the scattered light signal is the scattered light signal of the laser pulse transmitted through the optical fiber.

[0023] Based on the scattered light signals collected through each optical fiber, the strain of each optical fiber in the receiving acoustic system at the current well depth is determined by a preset strain determination method.

[0024] Based on the strain of the optical fiber in each acoustic receiver, waveform curves for each corresponding azimuth of the acoustic receiver are plotted, and the waveform curves for all azimuths are used as acoustic logging data for the current well depth of the well to be logged.

[0025] At least one embodiment of this application also provides a computer program product, including a computer program that, when executed by a processor, implements the steps of the fiber optic sensing acoustic wave detection method as described above.

[0026] The embodiments of this application provide a fiber optic acoustic wave detector, a fiber optic acoustic wave detection device, a fiber optic acoustic wave detection system, a fiber optic acoustic wave detection method, and a computer program product based on an elastic rod supporting multi-directional detection. Compared with the prior art, the fiber optic acoustic wave detector based on an elastic rod supporting multi-directional detection has a simple structure and can simultaneously detect acoustic wave signals from multiple directions. Furthermore, the receiving acoustic system of the fiber optic acoustic wave detection device using this fiber optic acoustic wave detector based on an elastic rod supporting multi-directional detection has a simple structure, can simultaneously detect acoustic wave signals from multiple directions, and improves the stability and reliability of the instrument. At the same time, the fiber optic receiver of the fiber optic acoustic wave detection device disclosed in this application has advantages such as small size, easy maintenance, and high temperature resistance compared with traditional piezoelectric ceramic transducer receivers. In addition, since the fiber optic cable is used as a distributed sensor, the downhole acquisition line is eliminated, and the pulsed laser generator and optical demodulator can be installed on the surface, thus omitting the downhole acquisition circuit.

[0027] In addition, a boost unit and a transmitting transducer are provided in the transmitting acoustic system of the fiber optic sensing acoustic wave detection device, wherein:

[0028] The boost unit is used to amplify the transmission drive signal provided by the transmission line, thereby driving the transmission transducer to vibrate;

[0029] The transmitting transducer is used to convert electrical energy into mechanical energy according to the amplified transmitting drive signal, and then excite sound waves through vibration; wherein, the transmitting transducer includes:

[0030] One or more of the following: monopole emitter transducer, dipole emitter transducer, and quadrupole emitter transducer.

[0031] In addition, the optical fiber in the optical fiber sensing acoustic detector based on the elastic rod that supports multi-directional detection is a single-mode optical fiber.

[0032] In addition, the scattered light signal in the optical fiber sensing acoustic wave detection device is a backscattered Rayleigh light signal.

[0033] In addition, the control system of the fiber optic sensing acoustic wave detection system includes a well logging surface system.

[0034] In addition, the method further includes connecting the fiber optic sensing acoustic wave detection device via an optical-electric composite cable:

[0035] By controlling the optical fiber composite cable to perform lifting or lowering operations, the position of the optical fiber sensing acoustic wave detection device in the well to be tested can be controlled. Attached Figure Description

[0036] One or more embodiments are illustrated by way of example with reference numerals in the accompanying drawings. These illustrations do not constitute a limitation on the embodiments. Elements with the same reference numerals in the drawings are denoted as similar elements. Unless otherwise stated, the figures in the drawings are not to be limited by scale.

[0037] Figure 1 This is a schematic diagram of the structure of an optical fiber sensing acoustic wave detection device provided in an embodiment of the present disclosure;

[0038] Figure 2 A schematic diagram of another fiber optic sensing acoustic wave detection device provided in an embodiment of this disclosure;

[0039] Figure 3 This is a schematic diagram of the structure of an elastic rod provided in an embodiment of the present disclosure;

[0040] Figure 4 This is a schematic diagram of another elastic rod provided in an embodiment of the present disclosure;

[0041] Figure 5 This is a schematic diagram illustrating an application scenario of an optical fiber sensing acoustic wave detection device provided in an embodiment of this disclosure;

[0042] Figure 6 A flowchart of an optical fiber sensing acoustic wave detection method provided in this embodiment of the disclosure;

[0043] Figure 7 A flowchart of another fiber optic sensing acoustic wave detection method provided in this disclosure embodiment;

[0044] Figure 8 This is a schematic diagram of the structure of a fiber optic sensing acoustic wave detector based on an elastic rod that supports multi-directional detection, provided as an embodiment of this disclosure.

[0045] Figure label:

[0046] Figure 2 In the middle: 1-plug; 2-receiving acoustic system; 21-elastic rod; 22-optical fiber; 3-sound insulation body; 4-transmitting acoustic system; 41-quadrupole transmitting transducer; 42-dipole transmitting transducer; 43-monopolar transmitting transducer; 5-transmitting line; 6-well inclination azimuth logging tool; 7-remote transmission module; 8-horse head; 9-optical-electric composite cable;

[0047] Figure 5 In the middle: 10-Fiber optic sensing acoustic detection device; 20-Horse head; 30-Well shaft; 40-Optical fiber composite cable; 510-Head pulley; 520-Ground pulley; 60-Windlock; 70-Coupled and beam splitter; 80-Ground system; 810-Demodulator (modulation and demodulation module); 820-Pulse laser generator; 90-Logging vehicle. Detailed Implementation

[0048] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the various embodiments of the present invention will be described in detail below with reference to the accompanying drawings. However, those skilled in the art will understand that many technical details have been presented in the various embodiments of the present invention to enable the reader to better understand the present invention. However, the technical solutions claimed in the present invention can be implemented even without these technical details and various changes and modifications based on the following embodiments.

[0049] To facilitate understanding of the embodiments of this application, we will first introduce the relevant content of fiber optic sensing acoustic wave detector based on an elastic rod to support multi-directional detection.

[0050] Example 1

[0051] The embodiments of the present invention relate to an optical fiber sensing acoustic wave detector based on an elastic rod that supports multi-directional detection.

[0052] The following is a detailed description of the implementation details of the fiber optic sensing acoustic detector based on an elastic rod supporting multi-directional detection in this embodiment. The following content is only for the convenience of understanding and is not necessary for implementing this solution.

[0053] refer to Figure 8 This embodiment provides a fiber optic acoustic wave detector based on an elastic rod supporting multi-directional detection. The detector includes an elastic rod and multiple optical fibers; wherein:

[0054] Multiple through holes are provided inside the elastic rod along the axis of the elastic rod. The number of through holes is the same as the number of optical fibers, and the multiple through holes are arranged around the axis of the elastic rod with equal central angles.

[0055] Each optical fiber passes through a through-hole set along the axis of the elastic rod and extends into the interior of the elastic rod, with each through-hole allowing one optical fiber to pass through.

[0056] The fiber optic sensing acoustic detector based on an elastic rod that supports multi-directional detection provided in this embodiment can be applied to related acoustic logging devices.

[0057] As an example, in the fiber optic sensing acoustic detector based on an elastic rod that supports multi-directional detection provided in this embodiment, the optical fiber can be used to conduct externally emitted laser pulse signals; the elastic rod can be used to sensitize weak acoustic signals from the outside to cause disturbance in the optical fiber located inside it, thereby coupling the mechanical vibration caused by the weak acoustic signal into the scattered light signal of the laser pulse signal.

[0058] Among them, the scattered light signal is the backscattered Rayleigh light signal, the elastic rod is used to enhance sensitivity, and the elastic rod and the optical fiber set inside it will deform synchronously under the disturbance of the sound wave.

[0059] For example, four through holes (numbered 10, 20, 30, and 40) can be set inside the elastic rod, allowing four optical fibers (numbered 1, 2, 3, and 4) to pass through. Fiber 1 passes through through hole 10 and extends into the elastic rod, fiber 2 passes through through hole 20 and extends into the elastic rod, and so on.

[0060] It should be noted that, provided that the quantities of both are the same, the number of optical fibers and the number of through holes can be set according to actual needs.

[0061] In some embodiments, the optical fiber is a single-mode optical fiber.

[0062] Alternatively, single-mode optical fiber has advantages such as resistance to electromagnetic interference, high temperature resistance, large bandwidth, and long transmission distance.

[0063] In some possible application scenarios, the scattered light signal may include a first scattered light signal without acoustic disturbance and a second scattered light signal coupled with mechanical vibration caused by acoustic waves; wherein, both the first and second scattered light signals are backscattered Rayleigh light signals.

[0064] The fiber optic acoustic wave detector based on an elastic rod that supports multi-directional detection provided in the embodiments of this application has a simpler structure than the prior art, can simultaneously detect acoustic wave signals from multiple directions, and improves the stability and reliability of the instrument.

[0065] Example 2

[0066] The embodiments of the present invention relate to an optical fiber sensing acoustic wave detection device.

[0067] Compared to existing technologies, the embodiments of this invention achieve directional acoustic detection by employing multiple optical fibers arranged circumferentially. Compared to traditional acoustic logging instruments, this device eliminates the need for complex downhole acquisition circuits, resulting in high system stability and reliability.

[0068] The following is a detailed description of the implementation details of the fiber optic sensing acoustic wave detection device of this embodiment. The following content is only for the convenience of understanding and is not necessary for implementing this solution.

[0069] Figure 1 This is a schematic diagram of the structure of an optical fiber sensing acoustic wave detection device provided in an embodiment of this disclosure, as shown below. Figure 1As shown, the fiber optic sensing acoustic wave detection device provided in this embodiment includes:

[0070] The main body of the fiber optic sensing acoustic wave detection device;

[0071] The remote transmission module is located inside the fiber optic sensing acoustic wave detection device and is used to receive external transmission commands. The transmission commands are used to control the transmission line to provide transmission drive signals to the transmitting acoustic system.

[0072] The transmitting line is located inside the fiber optic sensing acoustic wave detection device and connected to the remote transmission module, and is used to provide a transmission drive signal to the transmitting acoustic system in response to the transmission command.

[0073] The transmitting acoustic system is located inside the fiber optic sensing acoustic wave detection device and connected to the transmitting line. It is used to amplify the transmitting drive signal provided by the transmitting line and perform the operation of exciting acoustic waves.

[0074] A sound insulation body is disposed between the transmitting sound system and the receiving sound system to block the direct wave excited by the transmitting sound system and propagating along the outer shell of the fiber optic sensing acoustic wave detection device.

[0075] The receiving acoustic system is located inside the fiber optic sensing acoustic wave detection device and is used to conduct externally emitted laser pulse signals and to enhance the sensitivity of weak acoustic signals from the outside to cause disturbance in the optical fiber located inside the receiving acoustic system, thereby coupling the mechanical vibration caused by the weak acoustic signal into the scattered light signal of the laser pulse signal.

[0076] The receiving acoustic system includes a fiber optic sensing acoustic detector based on an elastic rod that supports multi-directional detection, as described in the aforementioned embodiment.

[0077] It is understood that the receiving acoustic system of the fiber optic sensing acoustic wave detection device disclosed in this embodiment is provided with an elastic rod and multiple optical fibers. The multiple optical fibers are arranged inside the elastic rod in the form of equal central angles. The number of through holes is the same as the number of optical fibers. Each optical fiber passes through a through hole arranged along the axis of the elastic rod and extends into the interior of the elastic rod. Each through hole allows one optical fiber to pass through.

[0078] Specifically, the remote transmission module, transmitting line, transmitting acoustic system, sound insulation body, and receiving acoustic system are all housed inside the fiber optic sensing acoustic wave detection device. The specific connection methods between the modules in this fiber optic sensing acoustic wave detection device can be communication connections, electrical connections, or hard connections, etc., and can also include both communication and hard connections, or electrical and hard connections simultaneously, depending on actual needs. Among them:

[0079] The remote transmission module can be used for bidirectional communication with external devices or systems. For example, it can be used to receive control commands (such as transmission commands) sent by external devices or systems and forward the control commands to the corresponding transmitting acoustic system. The transmission command can be used to control the transmission line to provide transmission drive signals to the transmitting acoustic system.

[0080] According to the launch command, the launch line provides a launch drive signal to the launch acoustic system to drive the launch acoustic system to excite sound wave signals;

[0081] The transmitting acoustic system is used to amplify the transmission drive signal provided by the transmitting line and perform the operation of exciting acoustic waves (for example, to excite the acoustic transducer to vibrate, thereby exciting the acoustic wave signal).

[0082] Sound insulation is used to block direct waves excited by the transmitting sound system and propagating along the outer shell of the fiber optic sensing acoustic wave detection device; that is, sound insulation can be used to block the acoustic wave signal generated by the transmitting sound system from propagating along the outer shell of the fiber optic sensing acoustic wave detection device in the form of a direct wave.

[0083] External devices or systems can also send laser pulse signals to the fiber optic sensing acoustic wave detection device, while the receiving acoustic system can be used to conduct externally emitted laser pulse signals through its internal optical fibers, and to sensitize weak acoustic signals from the outside (e.g., wellbore and / or formation) to cause disturbance in the optical fibers located inside the receiving acoustic system, thereby coupling the mechanical vibration caused by the weak acoustic signals into the scattered light signal of the laser pulse signals.

[0084] In some embodiments, the scattered light signal is a backscattered Rayleigh light signal.

[0085] It should be noted that the external device or system can be a well logging surface system (hereinafter referred to as the surface system), which can communicate with the fiber optic sensing acoustic detection device through a remote transmission module.

[0086] The fiber optic sensing acoustic detection device provided in this embodiment employs a scheme of uniformly arranging multiple optical fibers circumferentially inside an elastic rod, enabling directional acoustic detection. Due to the high pressure resistance of the optical fibers, acoustic logging can be performed in high-temperature and high-pressure wellbore environments, offering advantages such as small size, easy maintenance, and high-temperature resistance. Compared to traditional acoustic logging instruments, this device eliminates the complex downhole acquisition circuitry, resulting in high system stability and reliability.

[0087] Example 3

[0088] The embodiments of the present invention are a detailed description of the above-described fiber optic sensing acoustic wave detection device.

[0089] In some embodiments, a boost unit and a transmitting transducer are provided in the transmitting acoustic system of the above-described fiber optic sensing acoustic wave detection device, wherein:

[0090] The boost unit is used to amplify the transmission drive signal provided by the transmission line, thereby driving the transmission transducer to vibrate;

[0091] The transmitting transducer is used to convert electrical energy into mechanical energy according to the amplified transmitting drive signal, and then excite sound waves through vibration; wherein, the transmitting transducer includes:

[0092] One or more of the following: monopole emitter transducer, dipole emitter transducer, and quadrupole emitter transducer.

[0093] It is understood that the transmitting transducer may include any one or a combination of monopole transmitting transducers, dipole transmitting transducers and quadrupole transmitting transducers.

[0094] The sound transmission system uses a piezoelectric ceramic transducer, which utilizes the inverse piezoelectric effect to convert electrical energy excitation into mechanical vibration.

[0095] Optionally, the transmitting line of the fiber optic sensing acoustic wave detection device drives the transmitting transducer to excite monopole, dipole, or quadrupole vibrations according to a specific timing sequence provided by the instructions issued by the ground system.

[0096] It should be noted that the ground system is connected to the fiber optic sensing acoustic detection device via a fiber optic composite cable. The ground system includes a laser generator, optical demodulator, beam splitter, host computer, etc.

[0097] The ground-based system's laser generator modulates and emits two clusters of laser pulses with specific time intervals and wavelengths. The lasers propagate along the single-mode fiber in the optical-electric composite cable. Some of the incident light is backscattered due to imperfect fiber purity. A beam splitter separates the scattered light and sends it to the ground-based system's demodulator, which receives, records, and displays the data on a host computer. By analyzing the phase information of the two backscattered beams, the strain at various points on the fiber can be obtained, thus providing vibration information. Uplink and downlink reflected waves are received, providing high-quality raw data for acoustic reflection imaging.

[0098] It should be noted that the application of fiber optic sensing acoustic wave detection devices in acoustic pressure detection mainly utilizes the change in the optical phase within the fiber to sense the acoustic pressure: ① Acoustic wave action: When an acoustic wave acts on an optical fiber, it causes axial strain in the fiber. This strain alters the phase of the Rayleigh scattered light signal within the fiber. Rayleigh scattering is elastic scattering and does not produce any nonlinear effects. Furthermore, Rayleigh scattered light from different locations can be distinguished by the time it takes for the light to reflect back to the fiber's transmitting end. ② Phase change: The fiber strain caused by the acoustic wave leads to a change in the phase of the transmitted light within the fiber. This phase change is linearly related to the acoustic wave acting on the fiber. Therefore, the acoustic signal can be linearly obtained by demodulating the optical phase change. ③ Phase difference extraction: By setting detection points (such as points A and B) at different locations on the fiber, and measuring the phase difference change of the probe light between points A and B, the axial strain change of the fiber segment between points A and B can be determined. This change in phase difference directly reflects the pressure distribution caused by the acoustic wave on the fiber.

[0099] In this embodiment, multiple optical fibers are arranged in a ring receiving array with equal central angles, and an elastic rod is used to enhance sensitivity, thereby achieving circumferential detection under miniaturized receiver conditions. There is no need to wind the optical fibers, and it can also avoid defects such as severe light attenuation and fiber breakage caused by excessively small curvature radius of the wound optical fibers. Moreover, it eliminates the need for complex downhole acquisition lines, resulting in high system stability and reliability. It overcomes the disadvantage of traditional piezoelectric crystals, which are affected by the Curie temperature of ceramic materials, leading to a decrease in piezoelectric coefficient and energy conversion efficiency under high temperature conditions. At the same time, it can avoid the problem of receiver amplitude saturation caused by high-energy transmission.

[0100] Example 4

[0101] Based on the above embodiments, this embodiment provides a specific example.

[0102] In this embodiment, the application of the fiber optic sensing acoustic wave detection device in well logging is used as an example for illustration.

[0103] Please refer to the following. Figure 2 , Figure 2 This is a schematic diagram of another fiber optic sensing acoustic wave detection device provided in an embodiment of this disclosure.

[0104] The sound transmission system can use a piezoelectric ceramic transducer, which utilizes the inverse piezoelectric effect to convert electrical energy excitation into mechanical vibration.

[0105] The transmitting acoustic system may include one or more of a monopole transmitting transducer, a dipole transmitting transducer, and a quadrupole transmitting transducer, for driving the transmitting acoustic system to excite acoustic waves downhole according to a specific transmitting sequence.

[0106] refer to Figure 3 and Figure 4The receiving acoustic system comprises a flexible rod and optical fibers located within it. One or more single-mode optical fibers, parallel to the rod's axis, are embedded inside the flexible rod. When only one fiber is embedded, it is centrally positioned; when multiple fibers are embedded, they are eccentrically arranged. Furthermore, these multiple fibers are evenly distributed circumferentially and close to one side of the flexible rod to achieve multi-directional detection. Additionally, a protective outer shell can be selectively installed around the receiving acoustic system according to actual needs.

[0107] There is a sound insulation material between the transmitting and receiving sound systems to block direct waves that propagate along the outer casing of the instrument.

[0108] It may also include a wellbore azimuth logging tool, which provides the spatial attitude of the fiber optic sensing acoustic detection device located downhole to reflect wellbore trajectory information. The measurement results of the acoustic logging tool can be spatially repositioned using wellbore azimuth logging data.

[0109] It may also include a motor head for connecting the optoelectronic composite cable to the fiber optic sensing acoustic detection device.

[0110] The ground system is connected to the fiber optic acoustic wave detection device via a fiber optic composite cable. The fiber optic composite cable includes electrical cables and single-mode optical fibers, which can be one or more strands. The fiber optic composite cable is wound on a reel to provide power for raising and lowering the fiber optic acoustic wave detection device.

[0111] The ground-based system includes a laser generator, optical demodulator, coupler, and beam splitter. Among these:

[0112] A laser generator is used to produce laser pulses of a specific wavelength, and an optical demodulator is used to demodulate the modulated laser signal returning from downhole.

[0113] Couplers and beam splitters are used to couple the laser signal generated by the transmitter to the optoelectronic composite cable and to guide the optical signal returning from downhole into the optical demodulator.

[0114] As an example, the near-wellhead end of the remote transmission module is mechanically connected to the head of the optoelectronic composite cable and electrically connected to the cable core of the optoelectronic composite cable. The ground system communicates with the downhole device through the remote transmission module, sending transmission parameters and commands, and can also supply power to the transmission line and the transmitting acoustic system. The natural gamma detector located in the remote transmission module can record and upload the formation natural gamma information that varies with depth in real time. A sound insulation body is set between the transmitting acoustic system and the receiving acoustic system. The sound insulation body is used to attenuate the direct waves propagating along the pressure-bearing shell of the downhole device to prevent them from being directly detected by the receiving acoustic system. The receiving acoustic system is set at the bottom of the fiber optic sensing acoustic wave detection device at the end away from the wellhead.

[0115] It should be noted that the number of pulsed laser generators, optical demodulators, couplers, and beam splitters in the ground system is the same as the number of single-mode optical fibers, and each fiber in the receiving acoustic system is individually connected via an optoelectronic composite cable. When there are multiple optical fibers, each group of pulsed laser generators, optical demodulators, couplers, and beam splitters is synchronously excited with the transmitting acoustic system.

[0116] For specific application scenarios of this fiber optic sensing acoustic wave detection device, please refer to [reference needed]. Figure 5 .

[0117] Example 5

[0118] Based on the above embodiments, this embodiment provides an optical fiber sensing acoustic wave detection system. This embodiment, based on the principle of distributed optical fiber sensing acoustic wave measurement, provides an optical fiber sensing acoustic wave detection system comprising:

[0119] The fiber optic sensing acoustic wave detection device described above;

[0120] The control system is connected to the remote transmission module of the fiber optic acoustic wave detection device. It is used to control the transmitting acoustic system of the fiber optic acoustic wave detection device to perform the operation of exciting acoustic waves, and to perform the operation of emitting laser pulses to the body of the fiber optic acoustic wave detection device. It also generates acoustic logging data based on the scattered light signal of the laser pulse signal collected by the fiber optic acoustic wave detection device.

[0121] Among them, the scattered light signal of the laser pulse signal is the backscattered Rayleigh light signal.

[0122] In some possible scenarios, the scattered light signals used in generating acoustic logging data include: a first scattered light signal without acoustic disturbance and a second scattered light signal coupled with mechanical vibrations caused by acoustic waves; wherein, both the first and second scattered light signals are backscattered Rayleigh light signals.

[0123] It should be noted that the control system of this fiber optic sensing acoustic wave detection system can be a ground system; for example, a well logging ground system.

[0124] As a specific example, the system may include: fiber optic sensing acoustic detection device, ground system, fiber optic composite cable and auxiliary tools.

[0125] The surface system may also include: winch module, well logging surface system, pulsed laser emitter, optical demodulator, coupler, beam splitter, depth module, etc.; auxiliary tools may include top and bottom slip rings, and tension module may be added selectively.

[0126] In some embodiments, the transmitting acoustic system contains monopole and dipole transducers, and the receiving acoustic system contains four circumferentially uniformly arranged single-mode optical fibers close to the side of the elastic rod and parallel to its axis. The ground system includes four pulsed laser generators, an optical demodulator, a coupler, and a beam splitter. This enables circumferential four-directional detection of monopole longitudinal waves and dipole transverse waves.

[0127] In some embodiments, the transmitting acoustic system contains monopole, dipole, and quadrupole transducers, and the receiving acoustic system contains four circumferentially uniformly arranged single-mode optical fibers close to the side of the elastic rod and parallel to its axis. The ground system includes four pulsed laser generators, an optical demodulator, a coupler, and a beam splitter. This enables circumferential four-directional detection of monopole longitudinal waves and dipole transverse waves.

[0128] In some embodiments, the transmitting acoustic system contains monopole and dipole transducers, and the receiving acoustic system contains eight circumferentially uniformly arranged single-mode optical fibers close to the side of the elastic rod and parallel to its axis. The ground system includes eight pulsed laser generators, an optical demodulator, a coupler, and a beam splitter. This enables circumferential eight-directional detection of monopole longitudinal waves and dipole transverse waves.

[0129] In some embodiments, the transmitting acoustic system contains monopole, dipole, and quadrupole transducers, and the receiving acoustic system contains eight circumferentially uniformly arranged single-mode optical fibers close to the side of the elastic rod and parallel to its axis. The ground system includes eight pulsed laser generators, an optical demodulator, a coupler, and a beam splitter, enabling circumferential eight-directional detection.

[0130] In some embodiments, the transmitting acoustic system contains a monopole, and the receiving acoustic system has a single-mode optical fiber embedded in an elastic rod along the axis of the elastic rod. The ground system includes a pulsed laser generator, an optical demodulator, a coupler, and a beam splitter.

[0131] In some embodiments, the transmitting acoustic system contains a monopole, and the receiving acoustic system has an embedded single-mode optical fiber parallel to the axis of the elastic rod, close to the side of the elastic rod, and eccentrically positioned. The ground system includes a pulsed laser generator, an optical demodulator, a coupler, and a beam splitter.

[0132] In some embodiments, the transmitting acoustic system contains a dipole transducer, and the receiving acoustic system contains four circumferentially uniformly arranged single-mode optical fibers close to the side of the elastic rod and parallel to its axis. The ground system includes four pulsed laser generators, an optical demodulator, a coupler, and a beam splitter. This enables circumferential four-directional dipole transverse wave detection.

[0133] In some embodiments, the transmitting acoustic system contains a dipole transducer, and the receiving acoustic system contains eight circumferentially uniformly arranged single-mode optical fibers close to the side of the elastic rod and parallel to its axis. The ground system includes eight pulsed laser generators, an optical demodulator, a coupler, and a beam splitter. This enables circumferential eight-directional dipole transverse wave detection.

[0134] Example 6

[0135] Based on the above embodiments, this embodiment provides a fiber optic sensing acoustic wave detection method based on the fiber optic sensing acoustic wave detection system described above.

[0136] Please refer to Figure 6 , Figure 6 A flowchart illustrating a fiber optic sensing acoustic wave detection method provided in this embodiment. The fiber optic sensing acoustic wave detection method provided in this embodiment includes the following steps:

[0137] Step 610: Determine the current well depth at the location of the fiber optic sensing acoustic detection device in the well to be tested.

[0138] Optionally, the movable end of the optoelectronic composite cable is mechanically and electrically connected to the downhole equipment using a screwdriver, while the fixed end is connected to the surface system and the optical modulation / demodulation module via slip rings. The cable core of the optoelectronic composite cable is connected to the surface system, and the optical fiber is connected to the optical modulation / demodulation module. The optoelectronic composite cable is lowered using a winch system, and the fiber optic sensing acoustic wave detection device is placed at a specific location within the well to begin detection. During the measurement process, the fiber optic sensing acoustic wave detection device can be raised, lowered, or suspended. The current well depth of the fiber optic sensing acoustic wave detection device within the well to be measured can be determined based on the length of the lowered optoelectronic composite cable.

[0139] Step 620: Emit a laser pulse to the fiber optic sensing acoustic wave detection device to acquire the scattered light signals collected by each optical fiber in the receiving acoustic system of the fiber optic sensing acoustic wave detection device.

[0140] Optionally, the system can communicate with the ground system via a remote transmission module, and synchronize with the ground system at specific time intervals to provide time for the transmission line.

[0141] Specifically, the acquisition of scattered light signals can include two stages: a first stage and a second stage.

[0142] In the first stage: a laser pulse is emitted into the well via a pulsed laser generator and the first scattered light signal collected through each optical fiber is demodulated and recorded. At this time, the transmission line is not working.

[0143] Step 630: Send a transmission command to the fiber optic sensing acoustic wave detection device to control the transmission line to provide a transmission drive signal to the transmitting acoustic system, so that the transmitting acoustic system amplifies the transmission drive signal provided by the transmission line and performs an excitation acoustic wave operation, and acquires the second scattered light signal coupled with the mechanical vibration caused by the acoustic wave collected by each optical fiber in the receiving acoustic system.

[0144] In the second stage: The remote transmission module forwards the transmission command from the ground system to the transmitting acoustic system. The transmission line drives the transmitting transducer to generate monopole, dipole, or quadrupole vibrations according to the specific timing provided by the command from the ground system (which can be a large time interval, with at least one excitation at each measurement location). The vibrations propagate through the wellbore fluid to the formation, are emitted through the geological anomaly, and return to the wellbore. The reflected waves act on the receiving acoustic systems at both ends of the transmitting acoustic system, causing deformation of the elastic rods and optical fibers located in the receiving acoustic systems. The optical modulation and demodulation module transmits laser pulses of a specific frequency according to the specific timing of the command sent by the ground system to the remote transmission module, demodulates and records the second scattered light signal collected through each optical fiber under acoustic disturbance.

[0145] Step 640: Based on the first and second scattered light signals collected through each optical fiber, determine the strain of each optical fiber in the receiving acoustic system at the current well depth using a preset strain determination method.

[0146] The methods for determining the pre-defined strain can include time-domain positioning and frequency-domain analysis methods.

[0147] Furthermore, time-domain positioning and frequency-domain analysis methods can be used to obtain the strain of the optical fiber at one or more depth locations.

[0148] Step 650: Based on the strain of the optical fiber in each acoustic receiver, generate waveform curves for each acoustic receiver at the corresponding azimuth, and use the waveform curves of all azimuths as acoustic logging data for the current well depth of the well to be logged.

[0149] Optionally, steps 610 to 650 are repeated at different depths within the wellbore by the fiber optic sensing acoustic detection device, thereby obtaining acoustic logging data corresponding to multiple depths.

[0150] Among them, the waveform curve is the curve of amplitude changing with time, and the origin of the coordinate system can be regarded as the excitation start time.

[0151] In some embodiments, the fiber optic sensing acoustic wave detection device is connected via an optical-electric composite cable, and the method further includes:

[0152] By controlling the optical fiber composite cable to perform lifting or lowering operations, the position of the optical fiber sensing acoustic wave detection device in the well to be tested can be controlled.

[0153] Specifically, by lifting or lowering the optical fiber composite cable, the position of the optical fiber sensing acoustic wave detection device in the well to be tested can be changed. After reaching the predetermined position, the optical fiber sensing acoustic wave detection device can be suspended at the current position.

[0154] As an example, based on the aforementioned fiber optic sensing acoustic wave detection system, the practical application of this fiber optic sensing acoustic wave detection method may include the following steps:

[0155] S1: The movable end of the optoelectronic composite cable is mechanically and electrically connected to the fiber optic sensing acoustic detection device located downhole using a horse-head connector. The fixed end of the optoelectronic composite cable is connected to the ground system and the optical modulation and demodulation module, respectively. The cable core of the optoelectronic composite cable is connected to the ground system, and the optical fiber is connected to the coupler and the splitter, respectively connected to the optical demodulator and the pulsed laser generator.

[0156] S2: The winch system lowers the optical fiber composite cable and places the fiber optic sensing acoustic wave detection device into a specific position in the well to start detection. During the measurement process, the fiber optic sensing acoustic wave detection device can be lifted, lowered, or suspended.

[0157] S3: The remote transmission module communicates with the ground system and synchronizes with the ground system at specific time intervals to provide time for the transmission line; the remote transmission module forwards the transmission command issued by the ground system to the transmission acoustic system, and the transmission line drives the transmission transducer to excite monopole, dipole, or quadrupole vibrations according to the specific timing provided by the command issued by the ground system; the pulsed laser generator emits two clusters of laser pulses of specific wavelengths according to the specific timing of the command issued by the ground system, and the optical demodulator records and stores the backscattered Rayleigh light signal;

[0158] S4: Acoustic vibrations propagate through the wellbore and formation. Part of the vibration slides along the wellbore and is received by the acoustic receiving system, while the other part enters the formation and is reflected by an anomaly. The reflected wave returns to the wellbore and is received by the acoustic receiving system. The acoustic receiving system receives the acoustic vibrations, which cause the elastic rod to deform, and in turn, the optical fiber embedded in it to deform. At the same time, the laser signal travels down the optical fiber composite cable. At the point where the optical fiber undergoes elastic deformation due to vibration, the phase of the two clusters of laser signals changes.

[0159] S5: The modulated optical signal returns to the ground, passes through the beam splitter, is received by the optical demodulator, and is recorded and stored.

[0160] S6: Analyze the recorded and stored information such as the frequency and phase of the optical signal to obtain the vibration of the optical fiber at different orientations and positions at the depth point where the optical fiber sensing acoustic wave detection device is located.

[0161] S7: The roller pulls the optical fiber composite cable to rotate and lift the optical fiber sensing acoustic wave detection device. Repeat steps S1 to S5 to collect the scattered light signals from different directions at different depths and from each length segment of each optical fiber.

[0162] Example 7

[0163] Based on the above embodiments, this embodiment provides another fiber optic sensing acoustic wave detection method implemented based on the fiber optic sensing acoustic wave detection system described above.

[0164] Please refer to Figure 7 , Figure 7 A flowchart illustrating another fiber optic sensing acoustic wave detection method provided in this embodiment. The fiber optic sensing acoustic wave detection method provided in this embodiment includes the following steps:

[0165] Step 710: Determine the current well depth at the location of the fiber optic sensing acoustic detection device in the well to be tested.

[0166] Optionally, the movable end of the optoelectronic composite cable is mechanically and electrically connected to the downhole equipment using a screwdriver, while the fixed end is connected to the surface system and the optical modulation / demodulation module via slip rings. The cable core of the optoelectronic composite cable is connected to the surface system, and the optical fiber is connected to the optical modulation / demodulation module. The optoelectronic composite cable is lowered using a winch system, and the fiber optic sensing acoustic wave detection device is placed at a specific location within the well to begin detection. During the measurement process, the fiber optic sensing acoustic wave detection device can be raised, lowered, or suspended. The current well depth of the fiber optic sensing acoustic wave detection device within the well to be measured can be determined based on the length of the lowered optoelectronic composite cable.

[0167] Step 720: Send a transmission command to the fiber optic sensing acoustic wave detection device to control the transmission line to provide a transmission drive signal to the transmitting acoustic system, so that the transmitting acoustic system amplifies the transmission drive signal provided by the transmission line and performs the excitation of acoustic waves, and acquires the scattered light signal coupled with the mechanical vibration caused by the acoustic wave collected by each optical fiber in the receiving acoustic system; wherein, the scattered light signal is the scattered light signal of the laser pulse transmitted through the optical fiber.

[0168] Optionally, communication with the ground system is achieved via a remote transmission module, and time synchronization with the ground system is performed at specific time intervals to provide time for the transmission line. A pulsed laser generator transmits laser pulses downhole, and the scattered light signals collected through each optical fiber are demodulated and recorded.

[0169] The remote transmission module forwards the transmission commands from the ground system to the transmitting acoustic system. The transmitting line drives the transmitting transducer to generate monopole, dipole, or quadrupole vibrations according to the specific timing provided by the ground system (which can be a relatively long time interval, with at least one excitation at each measurement location). The vibrations propagate through the wellbore fluid to the formation, are emitted through geological anomalies, and return to the wellbore. The reflected waves act on the receiving acoustic systems at both ends of the transmitting acoustic system, causing deformation of the elastic rods and optical fibers located in the receiving acoustic systems. The optical modulation and demodulation module transmits laser pulses of a specific frequency according to the specific timing of the commands sent from the ground system to the remote transmission module, demodulates, and records the scattered light signals collected through each optical fiber under acoustic disturbance.

[0170] Step 730: Based on the scattered light signals collected through each optical fiber, determine the strain of each optical fiber in the receiving acoustic system at the current well depth using a preset strain determination method.

[0171] The methods for determining the pre-defined strain can include time-domain positioning and frequency-domain analysis methods.

[0172] Furthermore, time-domain positioning and frequency-domain analysis methods can be used to obtain the strain of the optical fiber at one or more depth locations.

[0173] Step 740: Based on the strain of the optical fiber in each acoustic receiver, generate waveform curves for each acoustic receiver at the corresponding azimuth, and use the waveform curves of all azimuths as acoustic logging data of the well to be logged at the current well depth.

[0174] Optionally, steps 710 to 740 are repeated at different depths within the wellbore by the fiber optic sensing acoustic detection device, thereby obtaining acoustic logging data corresponding to multiple depths.

[0175] Among them, the waveform curve is the curve of amplitude changing with time, and the origin of the coordinate system can be regarded as the excitation start time.

[0176] In some embodiments, the fiber optic sensing acoustic wave detection device is connected via an optical-electric composite cable, and the method further includes:

[0177] By controlling the optical fiber composite cable to perform lifting or lowering operations, the position of the optical fiber sensing acoustic wave detection device in the well to be tested can be controlled.

[0178] Specifically, by lifting or lowering the optical fiber composite cable, the position of the optical fiber sensing acoustic wave detection device in the well to be tested can be changed. After reaching the predetermined position, the optical fiber sensing acoustic wave detection device can be suspended at the current position.

[0179] Example 8

[0180] Based on the above embodiments, this embodiment provides a computer device, including a memory, a processor, and a computer program stored in the memory, wherein the processor executes the computer program to implement the steps of the method described in the above embodiments.

[0181] In some embodiments of this example, a computer-readable storage medium is provided, on which a computer program is stored, which, when executed by a processor, implements the steps of the method described in the above embodiments.

[0182] In some embodiments of this example, a computer program product is provided, including a computer program that, when executed by a processor, implements the steps of the method described in the above embodiments.

[0183] The processor may include, but is not limited to, one or more processors or microprocessors. Each processor may be implemented as an Application Specific Integrated Circuit (ASIC), Digital Signal Processor (DSP), Digital Signal Processing Device (DSPD), Programmable Logic Device (PLD), Field Programmable Gate Array (FPGA), controller, microcontroller, microprocessor, or other electronic component, for executing the methods in the above embodiments.

[0184] Computer-readable storage media can be implemented by any type of volatile or non-volatile storage device or a combination thereof. Computer-readable storage media may include, but are not limited to, random access memory (RAM), read-only memory (ROM), flash memory, EPROM memory, EEPROM memory, registers, computer storage media (e.g., hard disk, floppy disk, solid-state drive, removable disk, CD-ROM, DVD-ROM, Blu-ray disc, etc.).

[0185] Computer-readable storage media may also store at least one computer-executable program, such as computer-readable instructions. Computer-readable storage media include, but are not limited to, volatile memory and / or non-volatile memory. Volatile memory may include, for example, random access memory (RAM) and / or cache memory. Computer-readable storage media may include, for example, read-only memory (ROM), hard disk, flash memory, etc. For example, a non-transitory computer-readable storage medium may be connected to a computing device such as a computer, and then, when the computing device executes the computer-readable instructions stored on the computer-readable storage medium, the various methods described above can be performed.

[0186] In addition, the computer device may include (but is not limited to) a data bus, an input / output (I / O) bus, a display, and input / output devices (e.g., keyboard, mouse, speakers, etc.).

[0187] The processor can communicate with external devices via the I / O bus through wired or wireless networks.

[0188] In one embodiment, the at least one computer-executable instruction may also be compiled into or comprise a software product / computer program product, wherein one or more computer-executable instructions are executed by a processor to perform the steps of the various functions and / or methods in the embodiments described herein.

[0189] It should be understood that the terms "mechanism," "device," "component," etc., used in this application are merely one method of distinguishing different components, elements, parts, sections, or assemblies at different levels. However, if other terms can achieve the same purpose, they can be replaced by other expressions.

[0190] Those skilled in the art will understand that the above embodiments are specific examples of implementing the present invention. In practical applications, the technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification, and various changes can be made to them in form and detail without departing from the spirit and scope of the present invention.

Claims

1. A fiber optic sensing acoustic wave detector based on an elastic rod supporting multi-directional detection, characterized in that, It includes an elastic rod and multiple optical fibers; among which: Multiple through holes are provided inside the elastic rod along the axis of the elastic rod. The number of through holes is the same as the number of optical fibers, and the multiple through holes are arranged around the axis of the elastic rod with equal central angles. Each optical fiber passes through a through hole arranged along the axis of the elastic rod and extends into the interior of the elastic rod, with each through hole allowing one optical fiber to pass through.

2. The fiber optic sensing acoustic detector according to claim 1, characterized in that, The optical fiber is a single-mode optical fiber.

3. A fiber optic sensing acoustic wave detection device, characterized in that, include: The main body of the fiber optic sensing acoustic wave detection device; The remote transmission module is located inside the fiber optic sensing acoustic wave detection device and is used to receive external transmission commands. The transmission commands are used to control the transmission line to provide transmission drive signals to the transmitting acoustic system. The transmitting line is located inside the fiber optic sensing acoustic wave detection device and connected to the remote transmission module, and is used to provide a transmission drive signal to the transmitting acoustic system in response to the transmission command. The transmitting acoustic system is located inside the fiber optic sensing acoustic wave detection device and connected to the transmitting line. It is used to amplify the transmitting drive signal provided by the transmitting line and perform the operation of exciting acoustic waves. A sound insulation body is disposed between the transmitting sound system and the receiving sound system to block the direct wave excited by the transmitting sound system and propagating along the outer shell of the fiber optic sensing acoustic wave detection device. The receiving acoustic system is located inside the main body of the fiber optic sensing acoustic wave detection device. It is used to conduct externally emitted laser pulse signals and to enhance the sensitivity of weak acoustic signals from the outside to cause disturbance in the optical fiber located inside the receiving acoustic system, thereby coupling the mechanical vibration caused by the weak acoustic signal into the scattered light signal of the laser pulse signal. The receiving acoustic system includes a fiber optic sensing acoustic detector based on an elastic rod supporting multi-directional detection, as described in claim 1 or 2.

4. The apparatus according to claim 3, characterized in that, The transmitting acoustic system includes a boost unit and a transmitting transducer, wherein: The boost unit is used to amplify the transmission drive signal provided by the transmission line, thereby driving the transmission transducer to vibrate; The transmitting transducer is used to convert electrical energy into mechanical energy according to the amplified transmitting drive signal, and then excite sound waves through vibration; wherein, the transmitting transducer includes: One or more of the following: monopole emitter transducer, dipole emitter transducer, and quadrupole emitter transducer.

5. The apparatus according to claim 3, characterized in that, The scattered light signal is a backscattered Rayleigh light signal.

6. A fiber optic sensing acoustic wave detection system, characterized in that, include: The fiber optic sensing acoustic wave detection device according to any one of claims 3 to 5; The control system is connected to the remote transmission module of the fiber optic acoustic wave detection device and is used to control the transmitting acoustic system of the fiber optic acoustic wave detection device to perform the operation of exciting acoustic waves, to perform the operation of emitting laser pulses to the fiber optic acoustic wave detection device, and to generate acoustic logging data based on the scattered light signal of the laser pulse signal collected by the fiber optic acoustic wave detection device.

7. The system according to claim 6, characterized in that, The control system includes a well logging surface system.

8. A fiber optic sensing method for acoustic wave detection, characterized in that, Based on the system implementation of claim 6 or 7, the method includes: Determine the current well depth at which the fiber optic sensing acoustic detection device is located in the well to be tested; A transmission command is sent to the fiber optic sensing acoustic wave detection device to control the transmission line to provide a transmission drive signal to the transmitting acoustic system, so that the transmitting acoustic system amplifies the transmission drive signal provided by the transmission line and performs an excitation acoustic wave operation, and acquires the scattered light signal coupled with the mechanical vibration caused by the acoustic wave collected by each optical fiber in the receiving acoustic system; wherein, the scattered light signal is the scattered light signal of the laser pulse transmitted through the optical fiber. Based on the scattered light signals collected through each optical fiber, the strain of each optical fiber in the receiving acoustic system at the current well depth is determined by a preset strain determination method. Based on the strain of the optical fiber in each acoustic receiver, waveform curves for each corresponding azimuth of the acoustic receiver are plotted, and the waveform curves for all azimuths are used as acoustic logging data for the current well depth of the well to be logged.

9. The method according to claim 8, characterized in that, The method further includes connecting the fiber optic sensing acoustic wave detection device via an optical-electric composite cable: By controlling the optical fiber composite cable to perform lifting or lowering operations, the position of the optical fiber sensing acoustic wave detection device in the well to be tested can be controlled.

10. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by a processor, it implements the steps of the method of claim 8 or 9.

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