Streamline deepwater node piezoelectric detector and marine seismic node

Abstract

A streamline deepwater node piezoelectric detector and a marine seismic node. The piezoelectric detector comprises a detection assembly, a connector and an acoustically-transparent layer; the acoustically-transparent layer is connected to the connector; the detection assembly comprises a piezoelectric ceramic tube and end covers; the piezoelectric ceramic tube is coaxial with the connector, is provided with the end covers and is spaced apart from the connector. The marine seismic node comprises the piezoelectric detector. The piezoelectric detector provided by the present invention uses a streamline configuration mode, so as to improve the water flow impact resistance of the piezoelectric detector; meanwhile, the piezoelectric ceramic tube is spaced apart from the connector, such that when vibration of the node is transmitted to the connector, the vibration will not be transmitted to the piezoelectric ceramic tube or only a small amount of same is transmitted to the piezoelectric ceramic tube, and the piezoelectric ceramic tube will not be affected by node vibration or is only slightly affected by node vibration, thus improving the quality of data collected by the piezoelectric detector, and improving the quality of subsequent seismic profile data processing.

Description

Streamlined deepwater node piezoelectric geophone and marine seismic node

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of Chinese patent application 202311708013.X filed on December 12, 2023, the contents of which are incorporated herein by reference. Technical Field

[0003] The present invention relates to the field of deepwater geophysical exploration equipment, and in particular to a streamlined deepwater node piezoelectric geophone and an ocean seismic node. Background Art

[0004] Offshore oil exploration and data acquisition technologies are mainly divided into offshore streamer acquisition technology, submarine cable acquisition technology, ocean bottom seismometers, and ocean bottom node acquisition technology. Ocean bottom node acquisition technology uses node seismometers deployed on the seabed to record seismic signals generated in the seawater by the source ship and reflected by the subsea strata interface.

[0005] Compared with other acquisition technologies, it has the following advantages: First, it is less affected by marine facilities and can carry out seismic acquisition work in areas with dense production platforms and other obstacles at sea where TS cannot be implemented; second, it completely gets rid of the constraints of cables and can realize large offset and wide azimuth seismic data acquisition; third, compared with seafloor seismometers, seafloor node seismometers are cheaper and more convenient and accurate to deploy.

[0006] Seafloor node seismometers are four-component data acquisition devices. Piezoelectric geophones are a core component of the front-end data acquisition system. They utilize the piezoelectric effect of piezoelectric elements to convert acoustic pressure signals in seawater into electrical signals. Currently, mainstream piezoelectric geophones on the market have large radial dimensions, resulting in poor resistance to water impact. Furthermore, node vibrations are directly transmitted to the piezoelectric geophone's detection components, affecting the quality of seafloor node data acquisition and, in turn, the quality of subsequent seismic profile data processing.

[0007] Summary of the Invention

[0008] In order to solve the above technical problems or at least partially solve the above technical problems, the present invention provides a streamlined deep-water node piezoelectric detector and a marine seismic node.

[0009] The present invention provides a streamlined deep-water node piezoelectric detector, comprising a detection component, a connector and a sound-transparent layer, wherein the sound-transparent layer is connected to the end of the connector and forms a cavity inside the sound-transparent layer, the detection component comprises a piezoelectric ceramic tube arranged inside the cavity and end covers for sealing the two ends of the piezoelectric ceramic tube, one of the end covers is provided with two electrodes, one of the electrodes is connected to the inner wall of the piezoelectric ceramic tube, and the other electrode is connected to the outer wall of the piezoelectric ceramic tube, and the two electrodes are connected to a circuit module through a cable, wherein the piezoelectric ceramic tube is coaxial with the connector and the end cover provided with the electrodes and the connector are spaced apart along the axial direction of the piezoelectric ceramic tube.

[0010] Optionally, a support rod is passed through the interior of the piezoelectric ceramic tube, and both ends of the support rod are respectively connected to the two end covers.

[0011] Optionally, the end cap is provided with a first connection hole connected to the support rod and a second connection hole for connecting to the two electrodes, and the two second connection holes are symmetrically arranged relative to the first connection hole along the axial direction of the end cap.

[0012] Optionally, an accommodating cavity is formed at the end of the connector, and the end of the electrode can be inserted into the accommodating cavity, so that the electrode and the cable are connected in the accommodating cavity.

[0013] Optionally, a fixing layer is formed inside the accommodating cavity, and the cable passes through the fixing layer.

[0014] Optionally, one end of the support rod passes through the end cover and extends into the fixed layer.

[0015] Optionally, a first connecting rod and a second connecting rod are respectively provided at both ends of the support rod, the first connecting rod is connected to the first end cover, and the second connecting rod is connected to the second end cover.

[0016] Optionally, the first connecting rod is threadedly connected to the first end cover, and the second connecting rod is threadedly connected to the second end cover.

[0017] Optionally, a first sealing groove is provided on the outer periphery of one end of the connector close to the piezoelectric ceramic tube, and a first sealing ring matching the first sealing groove is provided on the inner wall of the sound-transmitting layer.

[0018] Optionally, a second sealing groove is provided on the outer periphery of one end of the connector away from the piezoelectric ceramic tube, and the second sealing groove is used to be connected to a second sealing ring on the marine seismic node.

[0019] Optionally, the sound-transmitting layer adopts a columnar structure, and the end of the sound-transmitting layer is hemispherical.

[0020] Optionally, the sound-transmitting layer is formed by casting.

[0021] Optionally, the thickness of the sound-transmitting layer is 2-3 mm.

[0022] Optionally, the distance between the end of the piezoelectric ceramic tube and the end of the connector is 5-10 mm.

[0023] The present invention also provides a marine seismic node, comprising any one of the above-mentioned streamlined deep-water node piezoelectric detectors.

[0024] The technical solution provided by the embodiments of the present invention has the following advantages compared with the prior art:

[0025] The piezoelectric geophone provided by the present invention adopts a streamlined setting, which can effectively reduce the size of the piezoelectric geophone along the radial direction and increase the piezoelectric geophone's ability to resist water flow impact. At the same time, the piezoelectric ceramic tube and the connector are spaced apart. After the vibration of the node is transmitted to the connector, the vibration will not be transmitted to the piezoelectric ceramic tube or will be transmitted to the piezoelectric ceramic tube in small amounts, thereby making the piezoelectric ceramic tube unaffected by the node vibration or less affected by the node vibration, thereby improving the quality of the data collected by the piezoelectric geophone and improving the quality of subsequent seismic profile data processing. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0027] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0028] FIG1 is a schematic structural diagram of a streamlined deep-water node piezoelectric geophone according to an embodiment of the present invention;

[0029] FIG2 is a cross-sectional view of a streamlined deep-water node piezoelectric geophone according to an embodiment of the present invention;

[0030] FIG3 is a schematic structural diagram of a connector according to an embodiment of the present invention.

[0031] Explanation of the accompanying symbols: 1. Detection component; 11. Piezoelectric ceramic tube; 12. First end cap; 13. Second end cap; 14. Electrode; 15. Support rod; 151. First connecting rod; 152. Second connecting rod; 2. Connector; 21. First sealing groove; 22. Second sealing groove; 23. Twist block; 3. Sound-transmitting layer; 4. Cable. DETAILED DESCRIPTION

[0032] In order to more clearly understand the above-mentioned objects, features and advantages of the present invention, the scheme of the present invention will be further described below. It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other.

[0033] The following description sets forth many specific details to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein; it is obvious that the implementation methods in the specification are only part of the implementation methods of the present invention, not all of the implementation methods.

[0034] As shown in Figures 1 and 2, the streamlined deepwater node piezoelectric detector provided in an embodiment of the present invention includes a detection component 1, a connector 2, and an acoustically transparent layer 3. The acoustically transparent layer 3 is connected to the end of the connector 2 and forms a cavity within the acoustically transparent layer 3. Part of the cavity within the acoustically transparent layer 3 accommodates the end of the connector 2, and the other part is used to accommodate the detection component 1, so that the detection component 1 and the connector 2 are arranged relative to each other within the cavity. The acoustically transparent layer 3 has good acoustic transparency and can also protect the detection component 1. The acoustically transparent layer 3 is preferably made of polyurethane material, and the acoustically transparent layer 3 is formed by casting the polyurethane material to ensure a sealing effect. At the same time, the polyurethane material has good acoustic transparency.

[0035] The detector assembly 1 comprises a piezoelectric ceramic tube 11 disposed within a cavity and end caps sealing the ends of the tube. The detector assembly 1 is used to sense seismic exploration signals. Piezoelectric ceramics exhibit a piezoelectric effect, generating an electric charge or voltage when force or pressure is applied. Therefore, piezoelectric ceramics have important applications in the sensor field.

[0036] For example, piezoelectric ceramics can be used in pressure sensors, measuring external pressure by measuring changes in charge or voltage. Piezoelectric ceramics are common components in the sensor field, and their operating principles are not described in detail here. Piezoelectric ceramic tube 11 has two open ends and two end caps, one at each end of the tube to seal the two open ends.

[0037] Specifically, the piezoelectric ceramic tube 11 has corresponding first and second ends. Taking the direction shown in Figure 2 as an example, the left end of the piezoelectric ceramic tube 11 is the first end of the piezoelectric ceramic tube 11, and the right end of the piezoelectric ceramic tube 11 is the second end of the piezoelectric ceramic tube 11. The end caps are divided into a first end cap 12 and a second end cap 13. The first end cap 12 is used to seal the first end of the piezoelectric ceramic tube 11, and the second end cap 13 is used to seal the second end of the piezoelectric ceramic tube 11. The manner in which the first end cap 12 is used to seal the first end of the piezoelectric ceramic tube 11 and the second end cap 13 is used to seal the second end of the piezoelectric ceramic tube 11 are not limited and can be designed according to actual needs.

[0038] Two electrodes 14 are provided on one end cap, specifically on the second end cap 13. The design of the two electrodes 14 is not limited and can be designed according to actual needs. One electrode 14 is connected to the inner wall of the piezoelectric ceramic tube 11, and the other electrode 14 is connected to the outer wall of the piezoelectric ceramic tube 11. Both electrodes 14 are connected to the circuit module via a cable 4.

[0039] Specifically, the inner and outer walls of piezoelectric ceramic tube 11 serve as a positive electrode and a negative electrode, respectively. When the inner wall of piezoelectric ceramic tube 11 serves as the positive electrode, the outer wall of piezoelectric ceramic tube 11 serves as the negative electrode. When the inner wall of piezoelectric ceramic tube 11 serves as the negative electrode, the outer wall of the inner wall of piezoelectric ceramic tube 11 serves as the positive electrode. Thus, the distribution of the positive and negative electrodes of piezoelectric ceramic tube 11 is not limited and can be selected based on the difficulty of manufacturing.

[0040] Among them, the piezoelectric ceramic tube 11 is coaxial with the connector 2, and the end cover provided with the electrode 14 is spaced apart from the connector 2 along the axial direction of the piezoelectric ceramic tube 11. Specifically, the axis of the piezoelectric ceramic tube 11 coincides with the axis of the connector 2, and the second end cover 13 is spaced apart from the connector 2 along the axial direction of the piezoelectric ceramic tube 11 to avoid direct contact between the connector 2 and the second end cover 13, thereby avoiding direct contact between the connector 2 and the piezoelectric ceramic tube 11.

[0041] In this design, the sound-transmitting layer 3 can be formed by casting. The coaxial arrangement of the piezoelectric ceramic tube 11 and the connector 2 can, on the one hand, make the thickness of the sound-transmitting layer 3 formed by casting uniform, so that the sound-transmitting layer 3 has better pressure resistance, so that the sound-transmitting layer 3 can better protect the detection component 1. On the other hand, it avoids increasing the radial dimension of the piezoelectric detector to increase the piezoelectric detector's ability to resist water flow impact. The piezoelectric ceramic tube 11 and the connector 2 are arranged at intervals so that after the vibration of the node is transmitted to the connector 2, the vibration will not be transmitted to the piezoelectric ceramic tube 11 or will be transmitted to the piezoelectric ceramic tube 11 in small amounts, thereby avoiding affecting the use of the piezoelectric ceramic tube 11.

[0042] The piezoelectric geophone provided by the present invention adopts a streamlined setting method, which can effectively reduce the radial dimension of the piezoelectric geophone and increase the piezoelectric geophone's ability to resist water flow impact. At the same time, the piezoelectric ceramic tube 11 is spaced apart from the connector 2. After the vibration of the node is transmitted to the connector 2, the vibration will not be transmitted to the piezoelectric ceramic tube 11 or will be transmitted to the piezoelectric ceramic tube 11 in small amounts, thereby making the piezoelectric ceramic tube 11 unaffected by the node vibration or less affected by the node vibration, thereby increasing the quality of the data collected by the piezoelectric geophone and the quality of the subsequent seismic profile data processing. In addition, the piezoelectric geophone under this design method can be applied to seismic exploration in deeper and more complex waters, improving the quality of seismic profile data processing.

[0043] As a feasible embodiment, the inner wall of the piezoelectric ceramic tube 11 serves as the positive electrode, and the outer wall of the piezoelectric ceramic tube 11 serves as the negative electrode. This is achieved by silver plating the inner and outer walls of the piezoelectric ceramic tube 11. The silver plating method and the method of using the inner and outer walls of the piezoelectric ceramic tube 11 as the positive electrode and the negative electrode, respectively, are conventional technologies. Therefore, the construction method and principle thereof are not described in detail here. Silver plating is used because silver has good electrical conductivity and excellent chemical stability, making it suitable as the material for the electrode 14 of the piezoelectric ceramic tube 11. Specifically, there are several reasons:

[0044] 1. Electrical Conductivity: Silver is one of the best electrical conductors with very low resistance. By plating the silver electrodes 14 on the piezoelectric ceramic tube 11, good current conduction and connection of the electrodes 14 can be provided.

[0045] 2. Interface effect: The interface between silver and the piezoelectric ceramic tube 11 has low contact resistance and contact characteristics of the electrode 14. The plating of the silver electrode 14 can provide good contact between the electrode 14 and the ceramic and reduce resistance loss.

[0046] 3. Chemical stability: Silver maintains good chemical stability under common environmental conditions and is not easily oxidized or corroded. This is crucial for protecting the piezoelectric ceramic electrode 14 from environmental influences and ensuring the long-term stability of the electrode 14's performance.

[0047] 4. Anti-oxidation layer: The outer layer of silver forms a dense oxide layer that helps protect the ceramic surface from oxygen and moisture. This is crucial for improving the service life and reliability of piezoelectric ceramic components. In piezoelectric ceramic applications, the use of silver-plated electrodes 14 provides better electrical performance, stability, and reliability, ensuring the effective performance of the piezoelectric effect.

[0048] In some embodiments, as shown in FIG2 , a support rod 15 is provided inside the piezoelectric ceramic tube 11, and both ends of the support rod 15 are respectively connected to the two end covers. The connection method between the two ends of the support rod 15 and the first end cover 12 and the second end cover 13 is not restricted and can be designed according to actual needs. By providing the support rod 15, the piezoelectric ceramic tube 11 and the two end covers can be connected into a stable integral structure.

[0049] The piezoelectric ceramic tube 11 is a single-tube design and is made of PZT5 material. The support rod 15 adopts a cylindrical structure, and a first connecting rod 151 and a second connecting rod 152 are respectively provided at both ends of the support rod 15. The first connecting rod 151, the second connecting rod 152 and the support rod 15 are integrally formed to increase the structural strength of the support rod 15. The first connecting rod 151 is connected to the first end cover 12, and the second connecting rod 152 is connected to the second end cover 13. In order to achieve resistance to high hydrostatic pressure, the outer periphery of the first connecting rod 151 and the second connecting rod 152 are both provided with threads, so that the first connecting rod 151 is threadedly connected to the first end cover 12, and the second connecting rod 152 is threadedly connected to the second end cover 13, thereby making the first end cover 12 and the second end cover 13 respectively cover the first end and the second end of the piezoelectric ceramic tube 11, thereby realizing the connection between the first end cover 12, the second end cover 13 and the piezoelectric ceramic tube 11.

[0050] Specifically, a threaded hole is provided in the middle of the first end cap 12, which is coaxial with the first end cap 12. A first connecting rod 151 is screwed into the threaded hole to connect the first end cap 12 with the first connecting rod 151. A through hole is provided in the middle of the second end cap 13, which is coaxial with the second end cap 13, so that the second connecting rod 152 can pass through the through hole and is screwed onto the protruding end of the second connecting rod 152 to connect the second end cap 13 with the second connecting rod 152. The first end cap 12 and the second end cap 13 are made of the same material, namely zirconia.

[0051] The end cap is provided with a first connection hole connected to the support rod 15 and a second connection hole for connecting to the two electrodes 14. The first connection hole here is the above-mentioned through hole. At this time, the end cap and the support rod 15 are limited by the above-mentioned nut connection method, and the second connection hole is connected to the electrode 14 by plugging. The two second connection holes are symmetrically arranged along the axial direction of the end cap relative to the first connection hole. This design method makes the two second connection holes and the first connection hole on the same straight line, and the straight line extends along the radial direction of the second end cap 13. In this application, the electrode 14 is made of a metal material with a gold-plated surface, so that it has good electrical conductivity.

[0052] The installation steps of the detection component 1 of this application are as follows:

[0053] Install two electrodes 14 on the second end cap 13 and label them: one electrode 14 is the positive electrode and the other is the negative electrode. Weld a thin wire to the lower end of the positive electrode post. The other end of the wire is connected to the inner wall of the piezoelectric ceramic tube 11. The wire is preferably 25 mm in diameter. Thread the first end cap 12 onto one end of a support rod 15. The other end of the support rod 15 passes through the through-holes in the piezoelectric ceramic tube 11 and the second end cap 13. Use an M2 nut to screw onto the protruding end of the support rod 15 to compress the piezoelectric ceramic tube 11, the first end cap 12, and the second end cap 13.

[0054] The negative pole of the electrode 14 is connected to the outer wall of the piezoelectric ceramic tube 11 through a silver wire. The silver wire is welded to the outer wall of the piezoelectric ceramic tube 11. There need to be three welding points between the silver wire and the outer wall of the piezoelectric ceramic tube 11. The welding time of each welding point cannot exceed 10 seconds. Because the outer wall of the piezoelectric ceramic tube 11 is silver-plated, if the welding time is too long, the silver layer will fall off, the capacitance and dielectric constant will change, and thus affect the sensitivity of the piezoelectric detector.

[0055] As shown in Figure 2, a accommodating cavity is formed at the end of the connector 2, which is connected to the internal cavity of the sound-transmitting layer 3. The accommodating cavity can allow the end of the electrode 14 to extend into, so that the electrode 14 and the cable 4 are connected in the accommodating cavity, effectively protecting the connection position between the electrode 14 and the cable 4.

[0056] In some embodiments, the acoustically transparent layer 3 is formed by casting. The cast liquid enters the accommodating cavity through the opening of the accommodating cavity, forming a fixed layer inside the accommodating cavity. In this case, the fixed layer covers the portion of the electrode 14 extending from the second end cap 13, the connection between the electrode 14 and the cable 4, and the outer periphery of the portion of the cable within the accommodating cavity. The cable 4 passes through the fixed layer and is connected to the circuit module of the marine seismic node through the connector 2.

[0057] In some embodiments, one end of the strut 15 passes through the end cap and extends into the fixed layer. Specifically, the second connecting rod 152 of the strut 15 passes through the second end cap 13 and extends into the accommodating cavity. The sound-permeable layer 3 is formed by pouring. During the pouring process, the poured liquid enters the accommodating cavity through the opening, forming a fixed layer inside the accommodating cavity, which in turn allows the fixed layer to wrap around the outer periphery of the second connecting rod 152. In this design, the fixed layer and the sound-permeable layer 3 are an integrated structure, which can enhance the connection between the sound-permeable layer 3 and the strut 15, and also enhance the connection between the sound-permeable layer 3 and the connector 2, while ensuring a sealing effect when the cable 4 passes through the connector 2.

[0058] Further optimized, the end of the connector 2 close to the detection component 1 is provided with a flared end, the inner wall of the flared end is formed with a first slope surface, and the outer periphery of the end of the second end cover 13 close to the connector 2 is formed with a second slope surface, and the first slope surface matches the second slope surface.

[0059] With this design, connector 2 and second end cap 13 are spaced apart along the axial direction of piezoelectric ceramic tube 11, and thus the first and second sloped surfaces are spaced apart along the axial direction of piezoelectric ceramic tube 11, thereby directly forming an annular fluid channel between the first and second sloped surfaces. During the liquid pouring process, the liquid will flow into the accommodating cavity along the fluid channel between the first and second sloped surfaces, allowing the fluid to enter the accommodating cavity smoothly and ensuring the formation of a fixed layer.

[0060] As shown in Figure 3, a first sealing groove 21 is provided on the outer periphery of the end of the connector 2 near the piezoelectric ceramic tube 11, and a first sealing ring is provided on the inner wall of the sound-transparent layer 3 to match the first sealing groove 21. This design can improve the sealing performance of the connection between the connector 2 and the sound-transparent layer 3.

[0061] In some embodiments, the sound-transmitting layer 3 is formed by casting. In this case, a first sealing groove 21 is provided on the outer periphery of one end of the connector 2 close to the piezoelectric ceramic tube 11. During the casting process of the sound-transmitting layer 3, a first sealing ring is formed at a position corresponding to the first sealing groove 21, thereby increasing the connection strength and sealing of the sound-transmitting layer 3 and the connector 2.

[0062] Further optimized, there are two first sealing grooves 21, which are spaced apart along the axial direction of the connector 2. Accordingly, there should also be two first sealing rings. This design can further increase the connection strength and sealing performance between the sound-transmitting layer 3 and the connector 2.

[0063] It is understandable that the number of first sealing grooves 21 can be greater than two, for example, three, four, etc., and multiple first sealing grooves 21 will be spaced apart along the axial direction of the connector 2. It can be seen that the number of first sealing grooves 21 can be designed according to actual needs.

[0064] A second sealing groove 22 is provided on the outer periphery of the end of the connector 2 away from the piezoelectric ceramic tube 11 . The second sealing groove 22 is used to connect to the second sealing ring on the marine seismic node.

[0065] Specifically, the connector 2 is used as a connector to install the streamlined deep-water node piezoelectric detector on the marine seismic node. Specifically, an installation position is provided on the marine seismic node, wherein the connector 2 and the installation position of the marine seismic node can be connected by plug-in or by threaded connection, and can be designed according to actual needs.

[0066] Among them, in order to increase the firmness of the connection, the connector 2 and the installation position of the marine seismic node are preferably connected by bolts. At this time, the installation position of the marine seismic node is provided with a connecting sleeve, the inner wall of the connecting sleeve is provided with an internal thread threadedly connected to the connector 2, and a second sealing groove 22 is provided on the inner wall of the end of the connecting sleeve. As the connector 2 is screwed on the connecting sleeve, the second sealing ring is inserted into the second sealing groove 22 to increase the sealing effect between the connector 2 and the marine seismic node.

[0067] Specifically, referring to Figure 3, the interior of the connector 2 has a perforation, which is connected to the accommodating cavity, so that the cable 4 can pass through the accommodating cavity and the perforation in sequence and connect to the circuit module of the marine seismic node. The diameter of the perforation is smaller than the diameter of the accommodating cavity, and the perforation is only required for the cable 4 to pass through. A fixed layer needs to be formed in the accommodating cavity.

[0068] An operating part is provided on the outer periphery of the connector 2, and the operating parts extend from both ends of the connector 2. Taking the direction shown in Figure 2 as an example, the part of the left end of the connector 2 extending from the operating part is connected to the sound-transmitting layer 3, and the part of the right end of the connector 2 extending from the operating part is connected to the installation position of the marine seismic node.

[0069] As shown in Figures 1 to 3 , the operating portion is a twist block 23 disposed on the periphery of the connector 2. To withstand high hydrostatic pressure, the thickness of the twist block 23 is 7-9 mm, preferably 8 mm. To increase operational convenience, the outer periphery of the twist block 23 can be hexagonal, facilitating manual or external tool operation of the twist block 23. By rotating the twist block 23, the connector 2 is screwed, facilitating connection between the connector 2 and the marine seismic node. It is understood that the twist block 23 can also adopt other polygonal structures, as long as it is convenient for operators to operate or facilitate operator operation with the help of external tools.

[0070] For further optimization, taking the direction shown in Figure 2 as an example, a sealing slot can be set at the right end of the twist block 23, and accordingly, a sealing block can also be set at the position corresponding to the installation position of the marine seismic node. Under this design method, during the screwing process of the twist block 23, the sealing block is inserted into the sealing slot until the end of the sealing block is completely in contact with the bottom of the sealing slot, and the twist block 23 is screwed into place to achieve a sealed connection between the twist block 23 and the installation position of the marine seismic node.

[0071] For further optimization, in order to further enhance the sealing effect, a sealing gasket may be provided at the bottom end of the sealing slot, so that after the twist block 23 is screwed into place, the end of the sealing block is supported on the sealing gasket.

[0072] The connector 2 at the right end of the torsion block 23 is cylindrical in design. Its outer circumference features a second sealing groove 22 and threads. The dimensions of this connector 2 match the fixed position dimensions of the piezoelectric geophone reserved for the marine seismic node, facilitating a better connection. The connector 2 at the left end of the torsion block 23 is also cylindrical in design. Its outer circumference features two first sealing grooves 21. This portion of the connector 2 is connected to the geophone assembly 1 via a polyurethane acoustically transparent layer 3, ensuring that the central axes of the connector 2 and geophone assembly 1 coincide.

[0073] The assembled detector assembly 1 (with the piezoelectric ceramic tube 11 and two end caps connected via struts 15) is connected to cable 4, which then passes through connector 2. To achieve optimal coupling, a certain distance must be maintained between the detector assembly 1 and connector 2, and the two components must remain perpendicular. This process is achieved by placing the detector assembly 1 and connector 2 in a single-shot casting mold, melting the polyurethane material at high temperature, and then cooling it to set the mold. This streamlined deepwater node piezoelectric detector design is compact, simple to manufacture, resistant to high hydrostatic pressure, and low noise.

[0074] In some embodiments, the cable 4 of the present application is made of a high-temperature, high-pressure resistant material, as the polyurethane must be subjected to temperatures of 80°C to melt during the casting process. The cable 4 is a two-core shielded cable 4 , one end of which is connected to the positive and negative electrodes 14 of the detector assembly 1 . The other end passes through the connector 2 and then connects to the circuit module of the marine seismic node via a three-core connector to transmit the collected data.

[0075] Specifically, cable 4 has a white wire and a blue wire. The white wire of cable 4 is connected to the positive electrode, and the blue wire is connected to the negative electrode. During the welding process, each welding point must be provided with an insulating sleeve, otherwise the insulation resistance between the positive and negative electrodes of the piezoelectric detector and the connector 2 will decrease, resulting in a decrease in the sensitivity of the piezoelectric detector. The other end of cable 4 needs to pass through connector 2 and then be connected to the circuit module of the marine seismic node through a three-core connector. In the three-core connector, pin 1 is the negative electrode, pin 2 is the positive electrode, and pin 3 is the shielding layer. This can greatly reduce the basic noise of the acquisition channel of the circuit module of the marine seismic node and improve the quality of the acquired data.

[0076] In some embodiments, the acoustically transparent layer 3 of the present application functions to withstand high hydrostatic pressure, protect the detector assembly 1, and transmit vibration-sensing acoustic wave signals. The acoustically transparent layer 3 is tightly connected to the detector assembly 1 of the piezoelectric geophone, maintaining good coupling and fully transmitting the seismic wave signals detected in the water by the piezoelectric geophone to the detector assembly 1. The thickness of the acoustically transparent layer 3 depends on the sensitivity of the piezoelectric geophone. The thinner the acoustically transparent layer 3, the higher the sensitivity of the piezoelectric geophone. Conversely, the thicker the acoustically transparent layer 3, the lower the sensitivity. Furthermore, the thinner the acoustically transparent layer 3, the less protective it provides to the piezoelectric geophone. Therefore, a balance between these two factors is necessary. The thickness of the acoustically transparent layer 3 is 2-3 mm.

[0077] The shape of the sound-transmitting layer 3 adopts a columnar structure, and the end of the sound-transmitting layer 3 is hemispherical, that is, the end of the sound-transmitting layer 3 is designed to be hemispherical. The piezoelectric detector of this shape is not only highly resistant to water flow impact and can withstand high hydrostatic pressure, but also can reduce noise, which is more suitable for the needs of deep-water exploration.

[0078] The sound-transmitting layer 3 is formed by casting. This design ensures a good fit between the sound-transmitting layer 3 and the detector assembly 1, maintaining good coupling and fully transmitting the seismic wave signal in the water detected by the piezoelectric detector to the detector assembly 1 of the piezoelectric detector.

[0079] The acoustically transparent layer 3 is formed through a secondary casting mold. To achieve high-pressure resistance, sealing, and sound transmission, mechanical simulation software was used to analyze the thickness of the layer 3. The thickness was controlled to 2-3 mm, meeting design requirements. Considering the mechanical design of the marine seismic node, the preferred thickness of the piezoelectric geophone's acoustically transparent layer 3 is 3 mm.

[0080] In some embodiments, the distance between the end of the piezoelectric ceramic tube 11 and the end of the connector 2 is 5-10 mm. With this distance, the connector 2 does not affect the normal operation of the piezoelectric ceramic tube 11 and does not increase the overall length of the streamlined deepwater node piezoelectric geophone. This reduces the size of the streamlined deepwater node piezoelectric geophone, reduces the space occupied when installed in a marine seismic node, and meets the required usage.

[0081] In the first embodiment, one of the assembly methods of the streamlined deep-water node piezoelectric detector provided by the present application is as follows:

[0082] In step S1, two electrodes 14 are mounted on the second end cap 13. One electrode 14 is labeled as positive and the other as negative. A thin wire is welded to the lower end of the positive electrode column. The other end of the thin wire is connected to the inner wall of the piezoelectric ceramic tube 11. The first end cap 12 is threadedly connected to one end of a support rod 15. The other end of the support rod 15 passes through the through holes in the piezoelectric ceramic tube 11 and the second end cap 13. An M2 nut is screwed onto the protruding end of the support rod 15 to compress the piezoelectric ceramic tube 11, the first end cap 12, and the second end cap 13. A section of silver wire is used to connect the negative electrode of the electrode 14 to the outer wall of the piezoelectric ceramic tube 11. The silver wire is welded to the outer wall of the piezoelectric ceramic tube 11, thereby completing the installation of the detector assembly 1.

[0083] In step S2, the assembled detection component 1 is connected to the cable 4. Specifically, the white wire of the cable 4 is connected to the positive electrode, and the blue wire is connected to the negative electrode. During the welding process, each welding point must be provided with an insulating sleeve. The end of the cable 4 away from the detection component 1 passes through the connector 2 and is connected to the circuit module of the marine seismic node through a three-core connector.

[0084] In step S3, after the cable 4 is connected, a certain distance must be maintained between the detection component 1 and the connector 2, and the detection component 1 and the connector 2 must be kept in a vertical state. The detection component 1 and the connector 2 in this state are then placed in a single casting mold for casting. The casting material is polyurethane to form a fixed layer in the accommodating cavity of the connector 2. The fixed layer is wrapped around the outer periphery of the cable 4 and the electrode 14, and at the same time can form a sound-transparent layer 3 between the detection component 1 and the connector 2.

[0085] In the second embodiment, another assembly method of the streamlined deep-water node piezoelectric detector provided by the present application is as follows:

[0086] In step S1, two electrodes 14 are mounted on the second end cap 13 and labeled as positive and negative. A thin wire is welded to the lower end of the positive electrode column, and the other end of the wire is connected to the inner wall of the piezoelectric ceramic tube 11. The first end cap 12 is threadedly connected to one end of a support rod 15. The other end of the support rod 15 passes through the through holes in the piezoelectric ceramic tube 11 and the second end cap 13. An M2 nut is screwed onto the protruding end of the support rod 15 to compress the piezoelectric ceramic tube 11, the first end cap 12, and the second end cap 13. A section of silver wire is used to connect the negative electrode of the electrode 14 to the outer wall of the piezoelectric ceramic tube 11. The silver wire is welded to the outer wall of the piezoelectric ceramic tube 11, thereby completing the installation of the detector assembly 1.

[0087] In step S2, the assembled detection component 1 is connected to the cable 4. Specifically, the white wire of the cable 4 is connected to the positive electrode, and the blue wire is connected to the negative electrode. During the welding process, each welding point must be provided with an insulating sleeve. The end of the cable 4 away from the detection component 1 passes through the connector 2 and is connected to the circuit module of the marine seismic node through a three-core connector.

[0088] In step S3, after the cable 4 is connected, a certain distance must be maintained between the detection component 1 and the connector 2, and the detection component 1 and the connector 2 must be kept in a vertical state. The detection component 1 and the connector 2 in this state are then placed in a single casting mold for casting. The casting material is polyurethane to form a fixed layer in the accommodating cavity of the connector 2. The fixed layer is wrapped around the outer periphery of the cable 4 and the electrode 14, and at the same time, a preliminary sound-transmitting layer 3 can be formed between the detection component 1 and the connector 2.

[0089] In step S4, the component obtained in step S3 is placed into a secondary casting mold, and polyurethane is cast therein to form a sound-transmitting layer 3 of a preset thickness.

[0090] The present invention also provides a marine seismic node, including the aforementioned streamlined deepwater node piezoelectric geophone. The streamlined deepwater node piezoelectric geophone incorporates all the technical features of the aforementioned streamlined deepwater node piezoelectric geophone. The marine seismic node is a multi-component seismometer located on the seafloor that can independently collect and record seismic signals. It features wide azimuth coverage, high construction efficiency, multi-component recording, and strong feasibility in complex terrain, making it a mainstream method for marine seismic acquisition.

[0091] The marine seismic node should also include a battery module and a circuit structure. The circuit structure has a circuit module and a three-component detector. The battery module is used to provide power to components such as the three-component detector. The circuit module is connected to the three-component detector and the streamlined deep-water node piezoelectric detector circuit of this application.

[0092] Specifically, the circuit module is connected to the electrode 14 of the streamlined deep-water node piezoelectric detector through a cable 4. Among them, the three-component detector is a special detector used in multi-wave exploration. Unlike single-component conventional seismic detectors, each detector is equipped with three mutually perpendicular sensors to record the three components of the particle vibration velocity vector, which is used to simultaneously record longitudinal waves, shear waves, and conversion waves. The three-component detector is a conventional technology in this field, so its structure and working principle are not described in detail here. In addition, the connection method between this circuit module, battery module and various components is a conventional technology in this field, so its specific structure and working principle are not described in detail here.

[0093] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article, or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or device. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of other identical elements in the process, method, article, or device comprising the element.

[0094] The foregoing description is intended only to provide specific embodiments of the present invention, which will enable those skilled in the art to understand and implement the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not intended to be limited to the embodiments described herein, but is to be construed in the widest possible manner consistent with the principles and novel features disclosed herein.

Claims

1. A streamlined deep-water node piezoelectric geophone, characterized in that: The invention comprises a detection component (1), a connector (2) and a sound-transmitting layer (3), wherein the sound-transmitting layer (3) is connected to the end of the connector (2) and a cavity is formed inside the sound-transmitting layer (3), wherein the detection component (1) comprises a piezoelectric ceramic tube (11) arranged inside the cavity and an end cap for sealing the two ends of the piezoelectric ceramic tube (11), wherein one of the end caps is provided with two electrodes (14), wherein one of the electrodes (14) is connected to the inner wall of the piezoelectric ceramic tube (11), and the other of the electrodes (14) is connected to the outer wall of the piezoelectric ceramic tube (11), and the two electrodes (14) are connected to a circuit module via a cable (4), wherein the piezoelectric ceramic tube (11) is coaxial with the connector (2), and the end cap provided with the electrodes (14) and the connector (2) are spaced apart from each other along the axial direction of the piezoelectric ceramic tube (11), and the distance between the end of the piezoelectric ceramic tube (11) and the end of the connector (2) is 5-10 mm.

2. The streamlined deep-water node piezoelectric geophone according to claim 1, characterized in that: A support rod (15) is inserted into the interior of the piezoelectric ceramic tube (11), and two ends of the support rod (15) are respectively connected to the two end covers.

3. The streamlined deep-water node piezoelectric geophone according to claim 2, characterized in that: The end cover is provided with a first connection hole connected to the support rod (15) and a second connection hole for connecting to the two electrodes (14), and the two second connection holes are symmetrically arranged relative to the first connection hole along the axial direction of the end cover.

4. The streamlined deep-water node piezoelectric geophone according to claim 2, characterized in that: An accommodating cavity is formed at the end of the connector (2), and the end of the electrode (14) can be inserted into the accommodating cavity, so that the electrode (14) and the cable (4) are connected in the accommodating cavity.

5. The streamlined deep-water node piezoelectric geophone according to claim 4, characterized in that: A fixing layer is formed inside the accommodating cavity, and the cable (4) passes through the fixing layer.

6. The streamlined deep-water node piezoelectric geophone according to claim 5, characterized in that: One end of the support rod (15) passes through the end cover and extends into the fixed layer.

7. The streamlined deep-water node piezoelectric geophone according to claim 2, characterized in that: A first connecting rod (151) and a second connecting rod (152) are respectively provided at both ends of the support rod (15); the first connecting rod (151) is connected to the first end cover (12), and the second connecting rod (152) is connected to the second end cover (13).

8. The streamlined deep-water node piezoelectric geophone according to claim 7, characterized in that: The first connecting rod (151) is threadedly connected to the first end cover (12), and the second connecting rod (152) is threadedly connected to the second end cover (13).

9. The streamlined deep-water node piezoelectric geophone according to claim 1, characterized in that: A first sealing groove (21) is provided on the outer periphery of one end of the connector (2) close to the piezoelectric ceramic tube (11), and a first sealing ring matching the first sealing groove (21) is provided on the inner wall of the sound-transmitting layer (3).

10. The streamlined deep-water node piezoelectric geophone according to claim 1, characterized in that: A second sealing groove (22) is provided on the outer periphery of one end of the connector (2) away from the piezoelectric ceramic tube (11), and the second sealing groove (22) is used to connect to a second sealing ring on a marine seismic node.

11. The streamlined deep-water node piezoelectric geophone according to claim 1, characterized in that: The sound-transmitting layer (3) adopts a columnar structure, and the end of the sound-transmitting layer (3) is hemispherical.

12. The streamlined deep-water node piezoelectric geophone according to claim 1, characterized in that: The sound-transmitting layer (3) is formed by casting.

13. The streamlined deep-water node piezoelectric geophone according to claim 1, characterized in that: The thickness of the sound-transmitting layer (3) is 2-3 mm.

14. A marine seismic node, characterized in that: It comprises the streamlined deep-water node piezoelectric detector as claimed in any one of claims 1 to 13.

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