Seaborne seismic source near-field detector

Abstract

The utility model provides a near-field detector for a marine seismic source, which relates to the technical field of marine signal detection devices, and aims to ensure the service life of a sensor, an inner shell and an outer shell are arranged outside a sensor assembly, the strength of the outer shell is greater than that of the inner shell, the sensor assembly is arranged in the inner shell, and the outer shell is arranged outside the inner shell. And the shell is cylindrical, so that the circumferential surface of the shell is an induction surface. The sensor assembly is arranged along the length direction of the housing, so that the circumferential surface of the housing is an induction surface, the induction area of the sensor can be increased, and the sensitivity of the detector is improved. The sensor assembly comprises a piezoelectric film, an inner shell and an outer shell are arranged on the outer side of the piezoelectric film, and the piezoelectric film is very thin, light in weight, very soft, capable of working passively, extremely durable and capable of bearing millions of times of bending and vibration. Therefore, the problem that a ceramic sensor in the prior art is poor in impact resistance can be solved.

Description

Technical Field

[0001] The utility model relates to the technical field of marine signal detection devices, in particular to a marine seismic source near-field detector. Background Art

[0002] In marine oil and gas seismic exploration, the most common method is to use an air gun as an artificial source, using the instantaneous release of high-pressure air to form artificial seismic waves, which can penetrate thousands of meters of strata on the seabed, and then receive and analyze the reflected waves from different strata to infer the distribution of strata, thereby inferring the distribution of seabed oil and gas resources. In the actual exploration process, in order to increase the output energy of the air gun source, a common method is to combine several air guns and use an air gun control system to accurately control the synchronous excitation of each air gun at the same time.

[0003] As a control system for controlling the excitation of airgun seismic sources, it is directly related to the synchronization and stability of marine airgun seismic source excitation, and is an important factor affecting the signal-to-noise ratio and resolution of seismic data. It plays an important role in improving the quality of seismic data and is the core part of offshore oil and gas exploration operations. The airgun seismic source control system can not only achieve high-precision synchronous control of airgun seismic sources, providing highly stable source signals for high-quality seismic exploration operations, but also complete a variety of delayed airgun seismic source control methods, providing a simpler implementation method for more difficult random seismic sources and stereo seismic sources in offshore seismic exploration operations, thereby providing effective source guarantees for new methods and technologies of offshore oil and gas exploration such as multi-ship and broadband.

[0004] As an important part of the airgun control system, the near-field geophone is mainly used to measure the source seismic wavelet released by the source airgun in marine exploration. Through wavelet analysis, it can monitor the working status of the source airgun, the change of the airgun sinking depth, and the pressure change. It is an instrument with high sensitivity, strong impact resistance and high reliability. Traditional sensors are made of piezoelectric ceramic materials, and the impact resistance is difficult to meet the use requirements. Utility Model Content

[0005] The purpose of the utility model is to provide an offshore seismic source near-field detector to solve the technical problem that the conventional sensors in the prior art are made of piezoelectric ceramic materials and are relatively fragile. The preferred technical solutions among the many technical solutions provided by the utility model can produce many technical effects as described below.

[0006] In order to achieve the above purpose, the utility model provides the following technical solutions:

[0007] The utility model provides an offshore seismic source near-field detector, comprising a sensor assembly, an outer shell, an inner shell, and a connector. The strength of the outer shell is greater than that of the inner shell, and the outer shell is arranged in a cylindrical shape. The sensor assembly is arranged in the inner shell, and the inner shell is fixed in the inner cavity of the outer shell so that the circumferential surface of the outer shell is a sensing surface. The connector is connected to the sensor assembly through a cable to transmit signals, wherein the sensor assembly includes a piezoelectric film.

[0008] Preferably, the sensor assembly includes a base, a film-coated tube, a positive electrode and a negative electrode, wherein the positive electrode and the negative electrode are arranged on the piezoelectric film, the film-coated tube is sleeved on the base, the piezoelectric film is distributed along the circumference of the film-coated tube, the base extends along the length direction of the outer shell, and the cable is connected to the base.

[0009] Preferably, the material of the piezoelectric film is polyvinylidene chloride.

[0010] Preferably, the base comprises a bracket and a base, and the bracket is detachably connected to the base.

[0011] Preferably, a sealing ring is arranged between the piezoelectric film and the base, a mounting position for mounting the sealing ring is arranged on the base, and the piezoelectric film is installed in a space formed between two sealing rings.

[0012] Preferably, the inner shell and the outer shell are both made of polyurethane.

[0013] Preferably, a boss is provided on the peripheral surface of the shell, a first fixing clip is provided on the boss, and a threaded hole for mounting parts is provided on the first fixing clip.

[0014] Preferably, the device further comprises a second fixing clip arranged on the cable, wherein the second fixing clip is arranged inside the housing.

[0015] The technical solution provided by this application document includes the following beneficial effects:

[0016] The utility model provides an offshore seismic source near-field detector, including a sensor component, an outer shell, an inner shell, and a connector, wherein the sensor component is used to sense external pressure. In order to ensure the service life of the sensor, an inner shell and an outer shell are arranged outside the sensor component, wherein the strength of the outer shell is greater than the strength of the inner shell. Since the sensor is relatively sensitive, only one layer of inner shell is arranged, that is, the sensor component is arranged in the inner shell, and the sensor component is easily damaged under the action of pressure. In order to ensure the service life of the sensor, an outer shell is arranged outside the inner shell, that is, the inner shell is fixed in the inner cavity of the outer shell, and the outer shell is arranged in a cylindrical shape so that the circumferential surface of the outer shell is all a sensing surface. The sensor component is arranged along the length direction of the outer shell, so that the circumferential surface of the outer shell is all a sensing surface, and the sensing area of ​​the sensor can be increased, thereby increasing the sensitivity of the detector. The connector is connected to the sensor component through a cable to transmit signals, wherein the sensor component includes a piezoelectric film, and the inner shell and the outer shell are arranged outside the piezoelectric film. The piezoelectric film is very thin, light, very soft, can work passively, and the piezoelectric film is extremely durable and can withstand millions of times of bending and vibration. This can solve the problem that ceramic sensors in the prior art have relatively weak impact resistance. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0018] Figure 1 is a schematic diagram showing a three-dimensional structure of an offshore seismic source near-field detector according to an exemplary embodiment;

[0019] Figure 2 is a cross-sectional view showing a near-field geophone for an offshore seismic source according to an exemplary embodiment;

[0020] Figure 3 is a schematic structural diagram of a sensor assembly according to an exemplary embodiment.

[0021] In the figure: 1. outer shell; 2. inner shell; 3. sensor assembly; 4. piezoelectric film; 5. base; 6. coated tube; 7. positive electrode; 8. negative electrode; 9. connector; 10. sealing ring; 11. boss; 12. first fixing clip; 13. second fixing clip; 14. cable. DETAILED DESCRIPTION

[0022] In order to make the purpose, technical solution and advantages of the utility model clearer, the technical solution of the utility model will be described in detail below. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other implementation methods obtained by ordinary technicians in this field without creative work belong to the scope of protection of the utility model.

[0023] This specific implementation provides an offshore seismic source near-field detector, which solves the technical problem in the prior art that traditional sensors are made of piezoelectric ceramic materials and are relatively fragile.

[0024] The following is an explanation of the embodiments with reference to the accompanying drawings. In addition, the embodiments shown below do not limit the contents of the utility model described in the claims. In addition, the entire contents of the structures represented by the following embodiments are not limited to the solutions required as the utility model described in the claims.

[0025] Reference Figure 1-Figure 3 The utility model provides an offshore seismic source near-field detector, including a sensor assembly 3, an outer shell 1, an inner shell 2, and a connector 9, wherein the sensor assembly 3 is used to sense external pressure. In order to ensure the service life of the sensor, an inner shell 2 and an outer shell 1 are arranged outside the sensor assembly 3, wherein the strength of the outer shell 1 is greater than the strength of the inner shell 2. Since the sensor is relatively sensitive, only one layer of the inner shell 2 is arranged, that is, the sensor assembly 3 is arranged in the inner shell 2, and the sensor assembly 3 is easily damaged under the action of pressure. In order to ensure the service life of the sensor, an outer shell 1 is arranged outside the inner shell 2, that is, the inner shell 2 is fixed in the inner cavity of the outer shell 1, and the outer shell 1 is arranged in a cylindrical shape, so that the circumferential surface of the outer shell 1 is a sensing surface. The sensor assembly 3 is arranged along the length direction of the outer shell 1, so that the circumferential surface of the outer shell 1 is a sensing surface, and the sensing area of ​​the sensor can also be increased, thereby increasing the sensitivity of the detector. The connector 9 is connected to the sensor assembly 3 through the cable 14 to transmit signals. The sensor assembly 3 includes a piezoelectric film 4, and an inner shell 2 and an outer shell 1 are arranged outside the piezoelectric film 4. The piezoelectric film 4 is very thin, light, very soft, and can work passively. The piezoelectric film 4 is extremely durable and can withstand millions of times of bending and vibration. This can solve the problem that the ceramic sensor in the prior art has relatively weak impact resistance.

[0026] When people install it, it is formed by injection molding. First, the sensor component 3 is connected to the connector through the cable 14, and the inner shell 2 is set on the outside of the sensor component 3 by injection molding, and then the sensor component 3 is wrapped, and then the sensor component 3 with the inner shell 2 is placed in the mold, and the outer shell 1 is formed by injection molding.

[0027] In this embodiment, the sensor assembly 3 includes a base 5, a coated tube 6, a piezoelectric film 4, a positive electrode 7 and a negative electrode 8, wherein the positive electrode 7 and the negative electrode 8 are arranged on the piezoelectric film 4, the coated tube 6 is sleeved on the base 5, the piezoelectric film 4 is distributed along the circumference of the coated tube 6, the base 5 extends along the length direction of the outer shell 1, and the cable 14 is connected to the base 5. When the piezoelectric film 4 receives pressure, it is transmitted to the coated tube 6, and then the coated tube 6 is transmitted to other devices through the cable 14.

[0028] In this embodiment, the material of the piezoelectric film 4, the positive electrode 7 and the negative electrode 8 is polyvinylidene chloride. The polyvinylidene chloride piezoelectric film 4 is a new type of high molecular polymer piezoelectric material, which has the advantages of light weight, thin thickness, high sensitivity, high mechanical strength, and wide frequency response range. The polyvinylidene chloride piezoelectric film 4 has good flexibility and processing performance, low acoustic impedance, wide frequency response, high chemical stability and fatigue resistance, low hygroscopicity, and good thermal stability, that is, resistance to moisture, most chemicals, oxidants, strong ultraviolet rays and radiation. The sensor made of the polyvinylidene chloride piezoelectric film 4 can withstand the action of strong electric fields due to its high dielectric strength. In addition, polyvinylidene chloride is light in weight, and its density is only 1 / 4 of that of lead zirconate titanate piezoelectric ceramics. The sensor made has little effect on the structure to be measured. In addition, it is easy to process and install, and the shape can be formulated according to actual needs and fixed with glue. In addition, this can better solve the problem of pressure measurement on the surface of brittle materials or impact interfaces in the field of impact explosion, and ensure the service life of the sensor assembly 3.

[0029] In this embodiment, in order to facilitate the installation of the coated tube 6, the base 5 includes a bracket and a base, and the bracket and the base are detachably connected. When people install it, they first separate the base from the bracket, install the coated tube 6 on the bracket, and then connect the base and the bracket together, thereby preventing the coated tube 6 from detaching from the base 5.

[0030] In the present embodiment, in order to prevent liquid polyurethane from filling between the coated tube 6 and the base 5, a sealing ring 10 is arranged between the piezoelectric film 4 and the base 5, and a mounting position for the sealing ring 10 is arranged on the bracket. The sealing ring 10 is arranged at least two locations and is distributed at both ends of the coated tube 6. In this way, the piezoelectric film 4 is installed in the space between the two sealing rings 10, that is, the piezoelectric film 4 is arranged on the outer peripheral surface of the coated tube 6 and in the middle position between the two sealing rings 10. The sealing ring 10 is used to ensure that room temperature polyurethane is prevented from entering the internal gap of the core tube during glue injection, so as to avoid affecting the deformation of the piezoelectric film 4 and ensure the sensitivity of the sensor component 3.

[0031] Among them, the materials of the inner shell 2 and the outer shell 1 are both polyurethane. Since the temperature to which the sensor component 3 is subjected is relatively low, when processing the inner shell 2, the inner shell 2 is injected at a relatively low temperature to form a low-temperature polyurethane, and when the outer shell 1 is injected, a relatively high-temperature polyurethane is used to form a high-temperature polyurethane layer, wherein the low-temperature polyurethane layer is a soft polyurethane, which is mainly a thermoplastic linear structure, has good stability, chemical resistance, resilience and mechanical properties, has smaller compression deformation, and has good heat insulation, sound insulation, shock resistance and anti-toxic properties. The high-temperature polyurethane layer is a hard polyurethane, which mainly has the characteristics of light weight, sound insulation, excellent heat insulation performance, chemical resistance, good electrical properties, easy processing, and low water absorption.

[0032] In this embodiment, in order to facilitate connection with other devices, a boss 11 is provided on the circumferential surface of the shell 1, and a first fixing clip 12 is provided on the boss 11. The first fixing clip 12 is provided with a threaded hole for mounting parts. The device can be an air gun body, thereby ensuring that the detector is stably connected to the air gun body.

[0033] In this embodiment, in order to prevent the cable 14 from being pulled and separated from the base 5 when people use it, a second fixing clip 13 is also included on the cable 14, and the second fixing clip 13 is arranged inside the outer shell 1. In this way, the second fixing clip 13 is arranged on the outer side of the inner shell 2 and the inner side of the outer shell 1. The distance between the cable 14 between the first fixing clip 12 and the base 5 will not change, thereby preventing the cable 14 from being separated from the base 5.

[0034] It should be noted that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", etc. used herein to indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, the terms "first", "second", "third", etc. are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0035] In the description of this article, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" 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 an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in this utility model can be understood according to the specific circumstances.

[0036] The above is only a specific implementation of the utility model, but the protection scope of the utility model is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed by the utility model, which should be included in the protection scope of the utility model. Therefore, the protection scope of the utility model should be based on the protection scope of the claims.

[0037] It is to be understood that the same or similar parts in the above embodiments can refer to each other, and the contents not described in detail in some embodiments can refer to the same or similar contents in other embodiments. The multiple schemes provided in this application include their own basic schemes, which are independent of each other and do not restrict each other, but they can also be combined with each other without conflict to achieve multiple effects together.

[0038] Although the embodiments of the present application have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations on the present application. A person skilled in the art may change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. A near-field geophone for an offshore earthquake source, characterized in that: The invention comprises a sensor assembly (3), an outer shell (1), an inner shell (2), and a connector (9); the strength of the outer shell (1) is greater than that of the inner shell (2), and the outer shell (1) is arranged in a cylindrical shape; the sensor assembly (3) is arranged in the inner shell (2), and the inner shell (2) is fixed in the inner cavity of the outer shell (1) so that the circumferential surface of the outer shell (1) is a sensing surface; the connector (9) is connected to the sensor assembly (3) through a cable (14) to transmit signals, wherein the sensor assembly (3) comprises a piezoelectric film (4).

2. The offshore seismic source near-field detector according to claim 1, characterized in that: The sensor assembly (3) also includes a base (5), a film-coated tube (6), a positive electrode (7) and a negative electrode (8), wherein the positive electrode (7) and the negative electrode (8) are arranged on the piezoelectric film (4), the film-coated tube (6) is sleeved on the base (5), the piezoelectric film (4) is distributed along the circumference of the film-coated tube (6), the base (5) extends along the length direction of the housing (1), and the cable (14) is connected to the base (5).

3. The offshore seismic source near-field detector according to claim 1, characterized in that: The material of the piezoelectric film (4) is polyvinylidene chloride.

4. The offshore seismic source near-field detector according to claim 2, characterized in that: The base (5) comprises a bracket and a base, and the bracket is detachably connected to the base.

5. The offshore seismic source near-field detector according to claim 2, characterized in that: A sealing ring (10) is arranged between the piezoelectric film (4) and the base (5), a mounting position for mounting the sealing ring (10) is arranged on the base (5), and the piezoelectric film (4) is installed in a space formed between the two sealing rings (10).

6. The offshore seismic source near-field detector according to claim 1, characterized in that: The materials of the inner shell (2) and the outer shell (1) are both polyurethane.

7. The offshore seismic source near-field detector according to claim 1, characterized in that: A boss (11) is provided on the circumferential surface of the housing (1), a first fixing clamp (12) is provided on the boss (11), and a threaded hole for mounting parts is provided on the first fixing clamp (12).

8. The offshore seismic source near-field detector according to claim 1, characterized in that: It also comprises a second fixing clip (13) arranged on the cable (14), wherein the second fixing clip (13) is arranged inside the housing (1).

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