Multi-mode while-drilling multi-pole sound wave imaging logging device and working method

Abstract

The invention discloses a multi-mode while-drilling multi-pole sound wave imaging logging device and a working method. The multi-mode while-drilling multi-pole sound wave imaging logging device comprises a transmitting transducer unit, a sound insulator, a receiving transducer and a circuit board. The transmitting transducer unit is installed at one end of the sound insulator, a plurality of inner notch grooves are formed in the instrument shell to form the sound insulator, the receiving transducers are installed on the instrument shell, a wiring groove is formed in the instrument shell, and a circuit in the wiring groove is connected with the circuit board. And the circuit board is connected with the transmitting transducer unit and the receiving transducer. The working mode of not emitting but only collecting is introduced into the working mode of the while-drilling multi-pole sound wave imaging logging device, while-drilling noise signals are collected, the characteristics of the signals are analyzed, and the influence of while-drilling noise on stratum information measurement is reduced. The signal-to-noise ratio of signals collected by the acoustic logging-while-drilling device is effectively increased, the real-time processing effect of the device is improved, the installation and maintenance difficulty is lowered, and the safety risk of device construction is lowered.

Description

Technical Field

[0001] The invention belongs to the technical field of geophysical logging, in particular to a multi-mode while-drilling multipole acoustic imaging logging device and a working method. Background Art

[0002] As unconventional oil and gas reservoirs, complex oil and gas reservoirs, and deep oil and gas reservoirs gradually become the main exploration and development targets, horizontal wells and high-angle wells have gradually become the main well types, and logging while drilling technology has also developed rapidly in recent years. Logging while drilling technology integrates drilling technology, logging technology, and reservoir description technology. It completes logging operations while drilling, reduces the time that the drilling rig occupies the well site, and saves costs from the integration of drilling and logging. Compared with conventional cable logging, in addition to saving costs, the information measured by logging while drilling is less affected by intrusion and can better reflect the true information of the original formation. Logging while drilling can detect overpressure formations in advance, guide drilling mud configuration, and perform geological guidance. In addition, in highly deviated wells, horizontal wells, or special geological environments (such as expansive clay and high-pressure formations), when cable logging is difficult or risky to operate, logging while drilling can replace it. At present, almost all offshore drilling activities use logging while drilling technology.

[0003] Because of these advantages, as an important part of LWD, LWD acoustic logging has also achieved great development in recent years. Both the basic theoretical research of LWD acoustic logging and the development of instruments have made great progress. LWD acoustic logging can not only be used for formation porosity calculation, artificial synthesis of theoretical seismic maps, and lithology identification, but also can accurately predict overpressure formations and analyze rock mechanical characteristics. The combination of LWD acoustic logging and seismic logging can locate the presence of abnormal formation pressure, allowing engineers to determine the optimal mud density window in advance, which not only improves drilling efficiency and drilling safety factor, but also makes it possible to lower the casing to the optimal depth and increase oil well production.

[0004] The main problem faced by the acoustic logging while drilling instrument in the process of instrument application is that the signal-to-noise ratio of the signal collected by the instrument is low, and the quality of the logging data obtained is poor in stability and reliability compared with cable logging. In addition, the design process of the acoustic logging while drilling instrument is complex, and the instrument installation and maintenance are difficult. One of the sources of noise signals in the signal of the acoustic logging while drilling instrument is the drilling noise during the actual drilling operation. The drilling noise seriously interferes with the effective signal, which poses a great challenge to the processing of the acoustic logging while drilling signal. The frequency of the noise while drilling is mainly concentrated in the low-frequency range below 5kHz. The main sources of the noise while drilling are the noise generated by the collision between the drill collar and the well wall, the vibration of the drill collar caused by rotary drilling, the noise generated by the mud flow during the mud circulation process, and the noise transmitted from the drill bit. The drilling noise collected by the acoustic logging while drilling instrument is affected by the parameters of the acoustic logging while drilling instrument, the upper and lower drilling tool combinations, the drill bit selection and the formation properties. Therefore, the frequency domain and time domain properties of drilling noise vary under different conditions, and real-time feature analysis of drilling noise signals is required to reduce its interference with effective formation information extraction.

[0005] Another major source of noise in the signal of the while drilling acoustic logging instrument is the direct wave signal caused by the insufficient sound insulation effect of the sound insulation of the while drilling acoustic logging instrument. When the monopole source on the while drilling acoustic logging instrument is emitted, a drill collar mode wave is excited. This vibration mode occupies a dominant position in the wave train and propagates along the drill collar. Since the amplitude of the drill collar mode wave is large and the arrival time is early, the drill collar mode wave arrives as the first wave in most formations and wellbore conditions and causes serious interference to the extraction of formation information. Therefore, the key to the while drilling formation longitudinal wave time difference measurement is to design a sound insulation with excellent performance.

[0006] In the existing acoustic logging while drilling devices, the routing of the through-line is usually achieved by setting an inner shaft inside the instrument or drilling a hole inside the instrument. When the inner shaft routing method is used, the inner shaft is usually a slender, thin-walled hollow tube with an outer groove, and the through-line is routed in the tube. The installation of the inner shaft is relatively difficult. In order to be able to install smoothly, there is usually a gap between the outer diameter of the inner shaft and the inner diameter of the outer shell. The mud passes through the space between the inner shaft and the outer shell. The scouring of the mud causes the vibration of the inner shaft and then collides with the outer shell to cause noise interference and reduce the signal-to-noise ratio. At the same time, the scouring of the mud is also easy to cause the wear of the inner shaft, which brings safety risks. The routing of the inner shaft has the risk of signal crosstalk between the power line and the communication line, and also reduces the stability of the instrument. In addition, when the size of the drill collar changes, the space reserved for the design of the sound insulation body of the acoustic logging while drilling instrument changes. The design of the inner shaft routing reduces the space for the design of the sound insulation body, reducing the possibility of achieving the optimal sound insulation performance of acoustic logging while drilling instruments of different sizes. The routing method of drilling holes inside the instrument shell is also very difficult to process. Summary of the invention

[0007] The purpose of the present invention is to solve the problems in the prior art and provide a multi-mode while-drilling multipole acoustic imaging logging device and a working method, which effectively improves the signal-to-noise ratio of the collected signals of the while-drilling acoustic logging device, improves the real-time processing effect of the device, reduces the difficulty of installation and maintenance, reduces the safety risk of device construction, reduces the impact of while-drilling noise on the operation of the while-drilling acoustic logging device, and improves the operating performance of the device.

[0008] In order to achieve the above object, the present invention adopts the following technical solutions:

[0009] A multi-mode while-drilling multipole acoustic imaging logging device comprises a transmitting transducer unit, a sound insulator, a receiving transducer and a circuit board;

[0010] The transmitting transducer unit is installed at one end of the sound insulator, a plurality of inner grooves are provided on the instrument housing to form the sound insulator, a plurality of receiving transducers are installed on the instrument housing, a wiring groove is provided on the instrument housing, the lines in the wiring groove are connected to the circuit board, and the circuit board is connected to the transmitting transducer unit and the receiving transducer.

[0011] Further, the transmitting transducer unit includes a quadrupole transmitting transducer and a monopole transmitting transducer, one end of the monopole transmitting transducer is connected to one end of the sound insulator, and the quadrupole transmitting transducer is installed at the other end of the monopole transmitting transducer;

[0012] Or one end of the quadrupole transmitting transducer is connected to one end of the sound insulator, and the monopole transmitting transducer is installed at the other end of the quadrupole transmitting transducer;

[0013] Alternatively, the transmitting transducer unit is a single transmitting transducer having both monopole transmitting and quadrupole transmitting functions.

[0014] Furthermore, the receiving transducer is mounted on a receiving strip, and a plurality of the receiving strips are arranged in the circumferential direction of the instrument housing.

[0015] Furthermore, a preamplifier circuit is provided on the receiving strip, and connectors are provided at both ends of the receiving strip, and the connectors are connected to the circuit board.

[0016] Furthermore, a power line or a communication line is arranged in the wiring groove, and the power line or the communication line is connected to the connector on the circuit skeleton through a sealing plug, and the power line or the communication line is connected to the circuit board through the connector, and the circuit board is connected to the receiving strip through the connector.

[0017] Furthermore, the circuit board is mounted on circuit frames at both ends of the instrument housing, water holes are arranged inside the circuit frame, and the circuit board is arranged inside the instrument housing.

[0018] Furthermore, the transmitting control circuit on the circuit skeleton is connected to the quadrupole transmitting transducer and the monopole transmitting transducer through a connector.

[0019] Furthermore, a cover plate is installed on the wiring trough, and the cover plate is fixed to the instrument housing by screws.

[0020] Furthermore, when the multi-mode multipole acoustic imaging logging device while drilling is working in a well, the inside and the outside of the instrument housing are filled with mud.

[0021] The working method of the multi-mode multipole acoustic imaging logging device while drilling comprises:

[0022] The monopole transmitting transducer transmits a signal, and the receiving transducer receives the signal, and then the quadrupole transmitting transducer transmits a signal, and the receiving transducer receives the signal;

[0023] The monopole transmitting transducer transmits a signal, and the receiving transducer receives a signal;

[0024] The quadrupole transmitting transducer transmits a signal, and the receiving transducer receives a signal;

[0025] The monopole transmitting transducer and the quadrupole transmitting transducer transmit signals in turn, and a signal collection state of only receiving but not transmitting is added to the working sequence of receiving signals;

[0026] In the monopole transmitting transducer transmitting signals and the receiving transducer receiving signals, a working state of only receiving but not transmitting signals is added;

[0027] In the process of transmitting signals by the quadrupole transmitting transducer and receiving signals by the receiving transducer, a working state of only receiving but not transmitting signals is added;

[0028] The monopole transmitting transducer transmits a signal, the receiving transducer receives a signal, then the quadrupole transmitting transducer transmits a signal, and the receiving transducer receives a signal. When the characteristics of the monopole and quadrupole signals collected by the device at multiple depth points meet specific conditions, the device automatically switches to the monopole transmitting transducer and the quadrupole transmitting transducer to transmit signals in turn, and a signal collection state of only receiving but not transmitting is added to the working sequence of the receiving signal.

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] The present invention provides a multi-mode multipole acoustic imaging logging device while drilling. By optimizing the design of the sound insulator of the acoustic logging device while drilling, an inner groove is provided on the sound insulator between the transmitting and receiving parts, which can effectively reduce the direct wave reaching the receiving end through the instrument housing. The inner groove parameters are gradually designed to have a wider stop band bandwidth of the sound insulator, thereby obtaining better sound insulation performance. The sound insulator design of the present invention can effectively attenuate the direct wave, reduce the influence of the direct wave interference, increase the formation applicability of the device, and ensure that the device accurately measures the formation longitudinal wave and transverse wave time difference information.

[0031] The present invention adopts the method of cutting grooves on the instrument housing to pass through the wires. By cutting wiring grooves on the circumference of the instrument housing, the power line and the communication line are routed separately to reduce signal crosstalk, effectively improve the signal-to-noise ratio of the collected signals of the while-drilling acoustic logging device, improve the real-time processing effect of the device, reduce the difficulty of installation and maintenance, reduce the complexity of the device, and reduce the safety risk of device construction. In addition, a larger space is reserved for the sound insulator, which increases the attenuation of the direct wave by the sound insulator and improves the original signal collection quality of the device. It has important application value for the optimized design and successful promotion and application of the while-drilling acoustic logging device. At the same time, this device design method has a wider applicability to the design of while-drilling acoustic devices with different drill collar sizes.

[0032] The present invention also provides a working method of a multi-mode multi-pole acoustic imaging logging device while drilling, which adopts multiple working modes, improves the working mode of the device, and adds a receiving-only, non-transmitting working state to some working modes. Through real-time analysis of drilling noise, a processing basis is provided for efficient extraction of formation signals, which effectively improves the quality of the real-time processing results of the device under the real-drilling and real-transmission working state, reduces the interference effect of drilling noise, and improves the performance of the device. The present invention adopts monopole and quadrupole transducers to transmit azimuth reception to measure the time difference of longitudinal and transverse waves of the formation, thereby obtaining parameters such as formation lithology, porosity, and rock mechanics, and can realize imaging of formation information at different azimuths around the well, and perform wellbore overpressure warning. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0034] Figure 1 It is a schematic structural diagram of the multi-mode while-drilling multipole acoustic imaging logging device of the present invention.

[0035] Figure 2 It is a schematic diagram of the appearance structure of the sound insulator of the present invention.

[0036] Figure 3 It is a schematic diagram of the casing groove routing structure of the present invention.

[0037] Figure 4 It is a schematic diagram of the circuit skeleton structure of the present invention.

[0038] Figure 5 The figure is a comparison diagram of the waveform and frequency spectrum of the drill collar mode wave before and after the inner diameter of the sound insulation body of the present invention is reduced.

[0039] Figure 6 This is a waveform spectrum comparison diagram of the drilling noise with different frequencies emitted normally by the sound source of the present invention.

[0040] Figure 7 This is a waveform spectrum comparison diagram of drilling noise with different frequencies emitted normally by a sound source after the inner diameter of the sound insulation body of the present invention changes.

[0041] Figure 8 It is a working timing diagram of different working modes of the present invention.

[0042] Among them: 1-quadrupole transmitting transducer, 2-monopole transmitting transducer, 3-instrument housing, 4-receiving strip, 5-mud, 6-stratum, 7-sound insulator, 8-receiving transducer, 9-wiring trough, 10-sealing plug, 11-circuit skeleton, 12-connector, 13-circuit board, 14-water eye. DETAILED DESCRIPTION

[0043] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0044] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0045] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0046] In the description of the embodiments of the present invention, it should be noted that if the terms "upper", "lower", "horizontal", "inner", etc. indicate an orientation or positional relationship based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the product of the invention is usually placed when in use, it is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, the terms "first", "second", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0047] In addition, if the term "horizontal" appears, it does not mean that the component must be absolutely horizontal, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", which does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0048] In the description of the embodiments of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal connection of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0049] The present invention is further described in detail below in conjunction with the accompanying drawings:

[0050] See also Figures 1 to 4The present invention provides a multi-mode multipole acoustic imaging logging device while drilling, comprising a quadrupole transmitting transducer 1, a monopole transmitting transducer 2, an instrument housing 3, a receiving strip 4, a sound insulator 7, a receiving transducer 8, a wiring slot 9, a sealing plug 10, a circuit skeleton 11, a circuit skeleton joint 12, a circuit board 13 and a water hole 14. The multi-mode multipole acoustic logging device while drilling of the present invention has two groups of transmitting transducers, one group is a quadrupole transmitting transducer 1, and the other group is a monopole transmitting transducer 2. The two transmitting transducers are independently installed at the bottom end of the sound insulator, wherein the quadrupole transmitting transducer 1 is located at the bottom of the monopole transmitting transducer 2. The positions of the monopole transmitting transducer 2 and the quadrupole transmitting transducer 1 can be interchanged, and the transmitting transducer unit can also be composed of a single transmitting transducer compatible with monopole transmitting and quadrupole transmitting functions. Part of the energy emitted by the transmitting transducer is transmitted to the formation 6 through the mud 5 and then returns to the wellbore to be received by the receiving transducer 8 located on the receiving strip 4. The energy received by different receiving transducers 8 propagates at different distances in the formation 6, so the arrival time is different. Multiple receiving strips 4 are arranged on the circumference of the instrument housing 3. The receiving strips 4 are attached with a preamplifier circuit to amplify the received signal in time. Connectors are arranged at both ends of the receiving strips 4. The receiving strips 4 are connected to the circuit board 13 through the connectors. The circuit board 13 is respectively connected to the quadrupole transmitting transducer 1, the monopole transmitting transducer 2 and the receiving transducer 8.

[0051] Another part of the energy emitted by the transmitting transducer is transmitted through the instrument housing 3 and received by the receiving transducer 8 on the receiving strip 4. This part of the energy is a direct wave or a drill collar mode wave. A plurality of internal grooves are provided inside the instrument housing 3 to form a sound insulator 7. A plurality of internal grooves of different widths are arranged inside the sound insulator 7. The instrument housing 3 uses the internal groove sound insulator 7 between the transmitting transducer and the receiving strip 4 to attenuate the direct wave. The structure of the sound insulator 7 is shown in FIG. Figure 2 As shown, when the device is working underground, the inside and outside of the instrument housing 3 are filled with mud 5.

[0052] The wiring diagram of the instrument housing 3 is as follows: Figure 3 As shown, two wiring troughs 9 are placed between two adjacent receiving strips 4 at a circumferential interval of 180°. The two wiring troughs 9 contain power lines and communication lines respectively. The wiring troughs 9 are sealed with covers, which are fixed to the instrument housing 3 by screws. The wires in the wiring troughs 9 are connected to the connectors 12 on the circuit skeleton 11 through sealing plugs 10 at both ends, and then connected to the circuit boards 13 at both ends of the device.

[0053] The signals collected by the receiving strips 4 around the instrument housing 3 are connected to the circuit board 13 inside the device through the connector for AD conversion, real-time processing and storage. The processing circuit performs real-time STC calculation to obtain the time difference between the longitudinal and transverse waves of the formation while collecting. A transmission control circuit is provided on the circuit skeleton 11 near the transmitting end. The transmission control circuit is connected to the quadrupole transmitting transducer 1 and the monopole transmitting transducer 2 through the connector 12. The transmission control circuit transmits by exciting the two transmitting transducers with high voltage.

[0054] The design of the circuit skeleton 11 inside the instrument housing 3 is as follows: Figure 4 As shown, the circuit board 13 is installed on the circuit skeleton 11 at both ends of the instrument housing 3, and a water hole 14 is set in the middle of the circuit skeleton 11 to ensure that the mud 5 can pass smoothly. After the circuit skeleton 11 at the top of the device is inserted into the instrument housing 3 from the top of the device, the circuit skeleton 11 is located inside the instrument housing 3, connected to the circumferential receiving strip 4 and two circumferential wiring grooves spaced 180° outside the instrument housing 3 through the connector 12, and installed and fixed to the housing 3. The upper end of the device is the near receiving end, and the circuit board 13 at the near receiving end has the functions of collection, storage, processing and communication. The circuit skeleton 11 at the bottom of the device is inserted into the instrument housing 3 from the bottom of the device.

[0055] In a specific embodiment of the present invention, there are 12 receiving transducers 8 in the receiving strip 4, and four circumferentially evenly distributed receiving strips 4 receive a total of 48 waveform signals, and each receiving strip 4 is 90° apart.

[0056] Compared with the device design with the inner shaft routing, the inner diameter of the corresponding sound insulator of the present invention becomes smaller, and the attenuation of the direct wave by the sound insulator becomes larger. The amplitude change and spectrum change of the drill collar wave obtained by the monopole emission before and after the inner diameter change are as follows: Figure 5 shown. Figure 5 It shows that when the inner diameter is reduced, the amplitude of the drill collar wave is reduced and the frequency bandwidth is narrowed, which means that the effective stopband bandwidth of the sound insulator is increased. It proves that removing the inner shaft in the present invention leaves room for improving the performance of the sound insulator and improves the original signal quality of the device. Figure 2 As shown, the inner diameter of the sound insulator can ensure the passage of mud and reduce the difficulty of installation and maintenance caused by the inner shaft routing design, while reducing the safety risks caused by mud scouring and wear of the inner shaft.

[0057] When drilling while drilling, the drilling noise has a great interference on the signal collected by the present drilling while multipole acoustic logging device. Through experiments, it is found that the characteristics of the response signal of the drilling while drilling noise received by the receiving transducer 8 at different positions are different, and the drilling while drilling noise frequency is different from the frequency of the response generated by the drilling while drilling noise in the received signal. Figure 6As shown in the figure, the waveform spectrum comparison of the drilling noise with different frequencies emitted by the sound source is shown. When the drilling noise is in the frequency band of 3.5-5kHz, the response of the drilling noise is mainly distributed in the frequency band of 2.5kHz-7.5kHz. The device has a characteristic frequency under the condition of specific design and specific connection, that is, the response of the drilling noise to this frequency is the largest. When the device design or the connection method of the upper and lower parts of the device changes, the characteristics of the drilling noise response also change. Figure 7 As shown, the waveform spectrum comparison of the downhole noise of different frequencies applied when the sound source normally emits after the inner diameter of the device's sound insulation body changes. Experiments have shown that the response of the downhole acoustic logging device to downhole noise is affected by many factors such as the noise source frequency, noise source location, formation properties, drill bit selection, device connection conditions, device mechanical design, device transducer location and characteristics, and the time-frequency characteristics are variable. In order to reduce the impact of downhole noise on downhole acoustic logging, the present invention proposes to collect downhole noise signals by adding a working state of only receiving but not transmitting signals to the device working sequence, and analyze the response of downhole noise in real time, so as to reduce the impact of downhole noise on downhole acoustic logging.

[0058] The present invention also provides a working method of a multi-mode while-drilling multipole acoustic imaging logging device:

[0059] The multi-mode multi-pole acoustic imaging logging device of the present invention includes seven transmitting and receiving working modes. The working sequence of each working mode is as follows: Figure 8 shown.

[0060] The first working mode is that the monopole transmitting transducer 2 transmits a signal and the receiving transducer 8 receives the signal, and then the quadrupole transmitting transducer 1 transmits a signal and the receiving transducer 8 receives the signal.

[0061] The second working mode is that the monopole transmitting transducer 2 transmits signals and the receiving transducer 8 receives signals.

[0062] The third working mode is that the quadrupole transmitting transducer 1 transmits signals and the receiving transducer 8 receives signals.

[0063] The fourth working mode is to add a signal collection state of only receiving but not transmitting to the working sequence of the first monopole transmitting transducer 2 and the quadrupole transmitting transducer 1 in which the monopole transmitting transducer 2 and the quadrupole transmitting transducer 1 transmit and receive signals in turn. In order to improve the efficiency of the device and the longest working time, the working state of only receiving but not transmitting accounts for a relatively small proportion in the entire sequence. In this working mode, the signal collected by only receiving but not transmitting is a noise signal, and its main component is the drilling noise signal. The collected noise signal is analyzed for the drilling noise characteristics through the downhole real-time processing function. The analysis of the drilling noise signal provides a basis for selecting processing parameters for the signal received when the monopole transmitting transducer 2 and the quadrupole transmitting transducer 1 transmit. And the relationship between the characteristics of the drilling noise signal and the properties of the drilling formation can be analyzed in real time according to the characteristic changes of the collected noise signal.

[0064] The fifth working mode is to add a working state of only receiving but not transmitting signals to the timing of the aforementioned second working mode, and its principle is the same as that of the fourth working mode.

[0065] The sixth working mode is to add a working state of only receiving but not transmitting signals to the timing of the aforementioned third working mode, and its principle is the same as that of the fourth working mode.

[0066] The seventh working mode is an intelligent switching working mode. When the device starts working, the transmission timing is the same as the first working mode, but the quadrupole and monopole signals while drilling are analyzed and processed in real time to extract their signal characteristics. When the monopole and quadrupole signal characteristics collected by the device at multiple depth points meet specific conditions, it can automatically switch to the fourth working mode. This working mode helps to reduce the consumption of storage space and improve the working efficiency and maximum working time of the device. When the real-time analysis is carried out, the time domain and frequency domain analysis of the quadrupole and multipole signals are performed, and the transmission and reception timing of the fourth working mode is switched when the energy and spectrum characteristics meet the requirements before the effective formation signal arrives. And switch back to the initial working state when the waveform characteristics collected by only listening but not transmitting meet specific conditions at multiple consecutive depth points.

[0067] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A multi-mode multipole acoustic imaging logging device while drilling, characterized in that: It comprises a transmitting transducer unit, a sound insulator (7), a receiving transducer (8) and a circuit board (13); The transmitting transducer unit is mounted on one end of a sound insulating body, a plurality of internal grooves are formed on the instrument housing (3) to form a sound insulating body (7), a plurality of receiving transducers (8) are mounted on the instrument housing (3), a wiring groove (9) is formed on the instrument housing (3), a line in the wiring groove (9) is connected to a circuit board (13), and the circuit board (13) is connected to the transmitting transducer unit and the receiving transducer (8).

2. A multi-mode multipole acoustic imaging logging device while drilling according to claim 1, characterized in that: The transmitting transducer unit comprises a quadrupole transmitting transducer (1) and a monopole transmitting transducer (2), one end of the monopole transmitting transducer (2) is connected to one end of the sound insulator, and the quadrupole transmitting transducer (1) is installed at the other end of the monopole transmitting transducer (2); Or one end of the quadrupole transmitting transducer (1) is connected to one end of the sound insulator, and the monopole transmitting transducer (2) is installed at the other end of the quadrupole transmitting transducer (1); Alternatively, the transmitting transducer unit is a single transmitting transducer having both monopole transmitting and quadrupole transmitting functions.

3. The multi-mode multipole acoustic imaging logging device while drilling according to claim 1, characterized in that: The receiving transducer (8) is mounted on a receiving strip (4), and a plurality of the receiving strips (4) are arranged in the circumferential direction of the instrument housing (3).

4. A multi-mode multipole acoustic imaging logging device while drilling according to claim 3, characterized in that: The receiving strip (4) is provided with a preamplifier circuit, and both ends of the receiving strip (4) are provided with connectors, and the connectors are connected to the circuit board (13).

5. The multi-mode multipole acoustic imaging logging device while drilling according to claim 1, characterized in that: A power line or a communication line is arranged in the wiring groove (9); the power line or the communication line is connected to a connector (12) on a circuit skeleton (11) via a sealing plug (10); the power line or the communication line is connected to a circuit board (13) via the connector (12); and the circuit board (13) is connected to a receiving strip (4) via the connector (12).

6. The multi-mode multipole acoustic imaging logging device while drilling according to claim 1, characterized in that: The circuit board (13) is mounted on a circuit frame (11) at both ends of the inside of the instrument housing (3); a water hole (14) is arranged inside the circuit frame (11); and the circuit board (13) is arranged inside the instrument housing (3).

7. A multi-mode while-drilling multipole acoustic imaging logging device according to claim 5 or 6, characterized in that: The emission control circuit on the circuit skeleton (11) is connected to the quadrupole emission transducer (1) and the monopole emission transducer (2) via a connector (12).

8. The multi-mode multipole acoustic imaging logging device while drilling according to claim 1, characterized in that: A cover plate is installed on the wiring trough (9), and the cover plate is fixed on the instrument housing (3) by means of screws.

9. The multi-mode multipole acoustic imaging logging device while drilling according to claim 1, characterized in that: When the multi-mode multipole acoustic imaging logging device while drilling is working in a well, the inside and outside of the instrument housing (3) are filled with mud (5).

10. The working method of the multi-mode multipole acoustic imaging logging device while drilling according to any one of claims 1 to 9, characterized in that: include: The monopole transmitting transducer (2) transmits a signal, and the receiving transducer (8) receives the signal, and then the quadrupole transmitting transducer (1) transmits a signal, and the receiving transducer (8) receives the signal; The monopole transmitting transducer (2) transmits a signal, and the receiving transducer (8) receives a signal; The quadrupole transmitting transducer (1) transmits a signal, and the receiving transducer (8) receives a signal; The monopole transmitting transducer (2) and the quadrupole transmitting transducer (1) transmit signals in turn, and a signal collection state of only receiving but not transmitting is added to the working sequence of receiving signals; In the monopole transmitting transducer (2) transmitting signals and the receiving transducer (8) receiving signals, a working state of only receiving signals but not transmitting signals is added; In the process of transmitting signals by the quadrupole transmitting transducer (1) and receiving signals by the receiving transducer (8), a working state of only receiving signals but not transmitting signals is added; The monopole transmitting transducer (2) transmits a signal, the receiving transducer (8) receives the signal, then the quadrupole transmitting transducer (1) transmits a signal, and the receiving transducer (8) receives the signal. When the characteristics of the monopole signal and the quadrupole signal collected at multiple depth points meet specific conditions, the monopole transmitting transducer (2) and the quadrupole transmitting transducer (1) are automatically switched to transmit signals in turn, and a signal collection state of only receiving but not transmitting is added to the working sequence of the receiving signal.

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