Marine seismic node acquisition device

Abstract

The present application provides an ocean seismic node acquisition device, belonging to the technical field of marine geophysical exploration. Inside the pressure-resistant inner housing of the device, there are a three-component geophone, a power supply and a circuit unit. Among them, the circuit unit is used to control the piezoelectric geophone to detect the seismic longitudinal wave pressure in seawater, control the three-component geophone to pick up the submarine seismic signals, and control the acoustic transducer for submarine positioning. The power supply is used to provide electrical energy for other components in the device. After the device is placed on the seabed, the device can independently perform detection work as a single node. After a certain period of time, the data stored in the acquisition circuit in the device can be exported through an external socket. Through this device, seismic data corresponding to 4 acquisition channels measured by the piezoelectric geophone and the three-component geophone can be obtained. Since there is no need to use a transmission cable to transmit data to the host system in real time, the cost is relatively low.

Description

Technical Field

[0001] This application relates to the technical field of marine geophysical exploration, and particularly to a marine seismic node acquisition device. Background Art

[0002] In recent years, as marine oil and gas resources have become the focus of international energy competition, offshore oil and gas exploration has increasingly become an important area of oil and gas exploration. Currently, conventional marine seismic data acquisition devices are marine streamer acquisition systems or submarine cable acquisition systems. The marine streamer acquisition system includes: a host system, acquisition units, and transmission cables. Among them, the acquisition units are immersed in water. The acquisition units include acquisition sensors and acquisition circuits for acquiring seismic data. The host system is arranged on a ship. The acquisition units are connected to the host system through transmission cables, and the cables are dragged by the ship to acquire seismic data, and the data is transmitted to the host system on the ship through the transmission cables for storage. The submarine cable acquisition system includes: a host system, acquisition units, and transmission cables. Among them, the host system is arranged on the ground. The acquisition units include geophones, and the geophones are fixed on the seabed for receiving seismic waves and are connected to the host system on the ground through transmission cables.

[0003] Both of the above two acquisition devices use transmission cables to connect the acquisition units and the host system, and the host system controls the acquisition units, and at the same time can timely transmit the data acquired by the acquisition units to the host system. With the development of geophysical exploration technology towards broadband, wide azimuth, high density, and high precision, the demand for the number of acquisition channels in offshore 3D exploration has also increased significantly. However, for the above-mentioned marine streamer acquisition system or submarine cable acquisition system, for each additional acquisition channel, the cost of the cable will increase significantly, resulting in a significant increase in the cost of data acquisition and poor economic benefits. Summary of the Invention

[0004] An embodiment of this application provides a marine seismic node acquisition device, which can obtain seismic data corresponding to 4 acquisition channels measured by a piezoelectric geophone and this three-component geophone. Since there is no need to use a transmission cable to transmit data to the host system in real time, the cost is relatively low. The technical solution is as follows:

[0005] A marine seismic node acquisition device is provided. The device includes: an outer housing, a pressure-resistant inner housing, at least two pressure-bearing end caps, a piezoelectric geophone, an acoustic transducer, a three-component geophone, an external socket, a power supply, and a circuit unit;

[0006] The outer housing includes an upper housing and a lower housing. The upper housing and the lower housing are buckled and wrapped outside the pressure-resistant inner housing, and the upper housing and the lower housing are detachably connected. The bottom of the lower housing is provided with multiple pairs of lower wedges arranged axially, and each pair of the bottom surfaces of the lower wedges has serrated patterns;

[0007] The interior of the pressure-resistant inner shell has a receiving chamber. Each port of the pressure-resistant inner shell is hermetically connected to at least one of the pressure-bearing end caps. The piezoelectric detector, the acoustic transducer, and the external socket are respectively fixed on the outer end faces of the at least two pressure-bearing end caps, and the piezoelectric detector, the acoustic transducer, and the external socket are all located inside the outer shell.

[0008] A power supply, a circuit unit, and a three-component detector are provided in the receiving chamber. The power supply and the circuit unit are both electrically coupled to the external socket.

[0009] The circuit unit includes an acquisition circuit and an acoustic circuit. The power supply, the acquisition circuit, and the piezoelectric detector are electrically coupled in sequence. The power supply, the acquisition circuit, and the three-component detector are electrically coupled in sequence. The acquisition circuit can process and store the data measured by the piezoelectric detector and the three-component detector. The power supply, the acoustic circuit, and the acoustic transducer are electrically coupled in sequence. The acoustic circuit and the acoustic transducer are used for underwater positioning.

[0010] In a possible design, the top surface of the upper shell is provided with multiple pairs of upper wedge feet arranged axially, and each pair of upper wedge feet can be clamped within a pair of lower wedge feet.

[0011] In a possible design, the connection between the upper shell and the lower shell is fixed by connecting bolts.

[0012] The middle part of the upper shell and the lower shell is fixed to the pressure-resistant inner shell by fastening bolts.

[0013] In a possible design, each end of the outer shell has at least two through holes.

[0014] In a possible design, the material of the outer shell is nylon 66.

[0015] In a possible design, the upper shell includes multiple upper sub-sections, and the lower shell also includes multiple lower sub-sections corresponding to the upper sub-sections.

[0016] In a possible design, the material of the pressure-resistant inner shell is aluminum alloy 7050.

[0017] In a possible design, the pressure-resistant inner shell includes two circular tubes, and the connection between the two circular tubes is communicated. One circular tube is used to accommodate the power supply, and the other circular tube is used to accommodate the circuit unit and the three-component detector.

[0018] The number of the pressure-bearing end caps is four, and each end of each circular tube is respectively connected to a pressure-bearing end cap.

[0019] In a possible design, a protective shell is provided on the acoustic transducer.

[0020] In a possible design, the power supply uses 18650 lithium battery cells.

[0021] In a possible design, the acquisition circuit includes: an attitude module, a conversion module, a main control module, a 4-channel acquisition module, a data transmission module, a data storage module, and a clock synchronization module;

[0022] The attitude module is used to obtain the azimuth state, the conversion module is used to convert the electric energy provided by the power supply, the main control module is used to implement clock frequency division, clock synchronization for subsea positioning, switching control of node test items, digital signal acquisition control, and analog signal output control, the 4-channel acquisition module is used to acquire the data measured by the piezoelectric geophone and the three-component geophone, the data transmission module is used to transmit data externally, the data storage module is used to store data, and the clock synchronization module is used to achieve 4-channel data acquisition synchronization and precise data acquisition synchronization between nodes.

[0023] In a possible design, the attitude module includes: an attitude sensor, electrically coupled to the main control module;

[0024] The attitude sensor can record the corresponding heading angle, pitch angle, and roll angle.

[0025] In a possible design, at least one handle is provided at the end of the pressure-resistant inner shell.

[0026] The device provided by the embodiment of the present application, by setting a pressure-resistant inner shell with a pressure-bearing end cover, facilitates fixing the piezoelectric geophone and the acoustic transducer on the pressure-bearing end cover. Inside the pressure-resistant inner shell, there are a three-component geophone, a power supply, and a circuit unit. Among them, the circuit unit is used to control the piezoelectric geophone to detect the seismic longitudinal wave pressure in seawater, control the three-component geophone to pick up the subsea seismic signal, and control the acoustic transducer for subsea positioning. The power supply is used to provide electric energy for other components in the device. An outer shell is covered outside the pressure-resistant inner shell. The outer shell can not only protect the pressure-resistant inner shell, the piezoelectric geophone, the acoustic transducer, and the external socket, but also be better fixed on the seabed through the lower wedge feet at the bottom. After the device is placed on the seabed, the device can independently perform detection work as a single node. Every once in a while, the data stored in the acquisition circuit in the device can be exported through the external socket. Through this device, seismic data corresponding to 4 acquisition channels measured by the piezoelectric geophone and the three-component geophone can be obtained. Since there is no need to use a transmission cable to transmit data to the host system in real time, the cost is relatively low. Description of the Drawings

[0027] To more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0028] Figure 1 is a schematic structural diagram of an ocean seismic node acquisition device provided by an embodiment of the present application;

[0029] Figure 2 is a schematic cross-sectional structural diagram of an ocean seismic node acquisition device provided by an embodiment of the present application.

[0030] The reference numerals of the various parts in the drawings are described as follows:

[0031] 1 - Outer housing;

[0032] 11 - Upper housing;

[0033] 111 - Upper sub - section;

[0034] 12 - Lower housing;

[0035] 121 - Lower sub - section;

[0036] 13 - Lower wedge foot;

[0037] 14 - Upper wedge foot;

[0038] 15 - Connecting bolt;

[0039] 16 - Fastening bolt;

[0040] 2 - Pressure - resistant inner housing;

[0041] 21 - Handle;

[0042] 3 - Pressure - bearing end cover;

[0043] 4 - Piezoelectric detector;

[0044] 5 - Acoustic transducer;

[0045] 51 - Protective housing;

[0046] 6 - Three - component detector;

[0047] 7 - External socket;

[0048] 8 - Power supply;

[0049] 9 - Circuit unit;

[0050] 91 - Acquisition circuit;

[0051] 92 - Acoustic circuit. Detailed implementation manners

[0052] To make the objectives, technical solutions and advantages of the present application clearer, the following will further describe in detail the implementation manners of the present application in conjunction with the accompanying drawings.

[0053] In the present application, unless otherwise clearly specified and defined, terms such as "installation", "connection", "coupling", "fixing" 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 directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific circumstances.

[0054] Figure 1 FIG. Figure 2 FIG. Figure 1 - Figure 2 As shown in FIGS.

[0055] The working principle of the device will be described in detail below:

[0056] In this device, the function of the outer housing 1 is to protect the pressure-resistant inner housing 2, the piezoelectric detector 4, the acoustic transducer 5 and the external socket 7, and prevent damage to the above structures during the dragging process on the seabed or during the ground movement, stacking and piling processes. At the bottom of the outer housing 1, there are wedge feet, and a groove is formed between two adjacent wedge feet, which is convenient for the wedge feet to be inserted and fixed in the seabed sand and gravel, and has good gripping ability on the seabed, so that the seabed grounding coupling effect is good.

[0057] The pressure-resistant inner housing 2 and the corresponding at least two pressure-bearing end caps 3 are used to provide a sealed and high-pressure-resistant environment for the three-component detector 6, the power supply 8 and the circuit unit 9, so that the device can work normally underwater.

[0058] The piezoelectric detector 4 is installed on the pressure-bearing end cap 3 of the pressure-resistant inner housing 2, and the signal line connected to the piezoelectric detector 4 passes through the pressure-bearing end cap 3 into the accommodation compartment of the pressure-resistant inner housing 2, and is thus electrically coupled to the acquisition circuit 91. The piezoelectric detector 4 is mainly used to collect the seismic longitudinal wave pressure transmitted in seawater, and convert the seismic longitudinal wave pressure signal into an electrical signal and transmit it to the acquisition circuit 91.

[0059] The three-component detector 6 includes three single-direction detectors, and the three single-direction detectors are axially installed perpendicular to each other in pairs. Taking the three axes as the X-axis, Y-axis and Z-axis respectively, the three single-direction detectors can collect the seismic shear wave signals in the X and Y directions and the seismic longitudinal wave signal in the Z direction respectively.

[0060] The acquisition circuit 91 is used to control the piezoelectric detector 4 and the three-component detector 6 to collect data, and acquire, process and store the above data.

[0061] The acoustic transducer 5 is installed on the pressure-bearing end cap 3 of the pressure-resistant inner housing 2, and the signal line connected to the acoustic transducer 5 passes through the pressure-bearing end cap 3 into the accommodation compartment of the pressure-resistant inner housing 2, and is thus electrically coupled to the acoustic circuit 92. The acoustic transducer 5 is mainly used to collect the acoustic wave pressure transmitted in seawater, and convert the acoustic wave pressure signal into an electrical signal and transmit it to the acoustic circuit 92. The electrical signal sent by the acoustic circuit 92 can also be transmitted to the acoustic transducer 5 and converted into an acoustic signal by the acoustic transducer 5 and emitted. Through the above process, the seabed positioning of the device can be realized, and there is no need to externally hang a transponder for acoustic positioning, which is convenient for the automatic deployment and recovery of the device.

[0062] The external socket 7 is installed on the pressure-bearing end cap 3 of the pressure-resistant inner housing 2, and the signal line connected to the external socket 7 passes through the pressure-bearing end cap 3 into the accommodation compartment of the pressure-resistant inner housing 2, and is thus electrically coupled to both the power supply 8 and the circuit unit 9. The external socket 7 is used to charge the power supply 8, provide timing for the circuit unit 9, and serve as a communication interface for transmitting data between this device and other devices.

[0063] The power supply 8 can store electrical energy and supply power to the piezoelectric detector 4, acoustic transducer 5, three-component detector 6, and circuit unit 9 in the device.

[0064] In the device provided by the embodiment of the present application, by providing a pressure-resistant inner housing 2 with a pressure-bearing end cap 3, it is convenient to fix the piezoelectric detector 4 and the acoustic transducer 5 on the pressure-bearing end cap 3. Inside the pressure-resistant inner housing 2, there are a three-component detector 6, a power supply 8, and a circuit unit 9. Among them, the circuit unit 9 is used to control the piezoelectric detector 4 to detect the seismic longitudinal wave pressure in seawater, control the three-component detector 6 to pick up the undersea seismic signal, and control the acoustic transducer 5 for undersea positioning. The power supply 8 is used to supply electrical energy to other components in the device. Outside the pressure-resistant inner housing 2, there is an outer housing 1. The outer housing 1 can not only protect the pressure-resistant inner housing 2, piezoelectric detector 4, acoustic transducer 5, and external socket 7, but also be better fixed to the seabed through the lower wedge feet 13 at the bottom. After the device is placed on the seabed, the device can independently perform detection work as a single node. After a certain period of time, the data stored in the acquisition circuit 91 in the device can be exported through the external socket 7. Through this device, seismic data corresponding to 4 acquisition channels measured by the piezoelectric detector 4 and the three-component detector 6 can be obtained. Since there is no need to use a transmission cable to transmit data to the host system in real time, the cost is relatively low.

[0065] The structures and working principles of each part of the device are described in detail below:

[0066] In a possible design, the top surface of the upper housing 11 is provided with multiple pairs of upper wedge feet 14 arranged axially, and each pair of upper wedge feet 14 can be clamped within a pair of lower wedge feet 13.

[0067] During the storage and transportation of the device on the ground, the design of the above structure facilitates the stable stacking and placement of the device, and also saves space.

[0068] In a possible design, the connection between the upper housing 11 and the lower housing 12 is fixed by connection bolts 15; the middle part of the upper housing 11 and the lower housing 12 is fixed to the pressure-resistant inner housing 2 by fastening bolts 16, so as to realize the outer housing 1 being fixedly covered on the pressure-resistant inner housing 2, making the outer housing 1 and the pressure-resistant inner housing 2 firmly connected as a whole to protect the pressure-resistant inner housing 2, piezoelectric detector 4, acoustic transducer 5, and external socket 7.

[0069] In a possible design, each end of the outer housing 1 has at least two through holes 17, which can play a role in strengthening the structure, saving materials, and facilitating handling.

[0070] In a possible design, the material of the outer housing 1 is nylon 66, that is, polyhexamethylene adipamide, which is a thermoplastic resin generally prepared by polycondensation of adipic acid and hexamethylenediamine. It is insoluble in common solvents and only soluble in m-cresol, etc. It has very high mechanical strength and hardness and great rigidity, so it can withstand the high pressure of the seabed and reduce the high pressure borne by the pressure-resistant inner housing 2.

[0071] In a possible design, the upper housing 11 includes a plurality of upper sub-sections 111, and the lower housing 12 also includes a plurality of lower sub-sections 121 corresponding to the upper sub-sections 111.

[0072] For example, the upper housing 11 may include 4 upper sub-sections 111. Correspondingly, the lower housing 12 includes 4 lower sub-sections, a total of 8 sub-sections, in pairs, buckling in sequence, which is convenient for processing and assembly.

[0073] In a possible design, the material of the pressure-resistant inner housing 2 is aluminum alloy 7050, which belongs to a high-strength heat-treatable alloy and has extremely high strength and resistance to exfoliation corrosion and stress corrosion cracking. It can withstand the high-pressure seabed environment, thus maintaining good airtightness.

[0074] In a possible design, the pressure-resistant inner housing 2 includes two circular tubes, and the connection between the two circular tubes is communicated. One circular tube is used to accommodate the power supply 8, and the other circular tube is used to accommodate the circuit unit 9 and the three-component geophone 6; the number of the pressure-bearing end caps 3 is four, and one pressure-bearing end cap 3 is connected to each end of each circular tube.

[0075] Specifically, the two circular tubes are axially parallel, and the adjacent arc surfaces are naturally fused and connected. The two ends of the circular tubes are hermetically connected to the pressure-bearing end caps 3, that is, a total of 4 end caps are installed. Based on the above two circular tubes, the accommodation cabin of the pressure-bearing inner housing includes two cylindrical cabins. One cabin is used to accommodate the power supply 8, and the other cabin is used to accommodate the circuit unit 9 and the three-component geophone 6.

[0076] A small hole is designed horizontally between the two cabins for wiring connection between the cabins. This cross-sectional shape design is neat and standard, easy to roll into profiles. When mass-producing, a large amount of cost and time can be saved, and the processing amount of the circular tubes is small. Therefore, the later mechanical processing is mainly to process the sealing surface structures at both ends.

[0077] The external socket 7, the piezoelectric geophone 4 and the acoustic transducer 5 in the device can be respectively installed on a sealing end cap of the pressure-resistant inner housing 2.

[0078] In a possible design, a protective shell 51 is provided on the acoustic transducer 5 to prevent the acoustic transducer 5 from being damaged by external forces. Circular sound-transmitting holes are designed around the radial circumference of the protective shell 51 of the acoustic transducer 5, so that the function of the acoustic transducer 5 will not be affected.

[0079] In a possible design, a pressure balance piston is also provided on the acoustic transducer 5 to balance the pressure received by the acoustic transducer 5.

[0080] In a possible design, the power supply 8 uses 18650 lithium battery cells to ensure that it can be used for a long time after a single charge, for example, 30 - 40 days.

[0081] Specifically, the 18650 lithium battery cells are combined in series and parallel to achieve the output voltage and capacity suitable for the circuit. The output line of the power supply 8 is connected to the acquisition circuit 91, the acoustic circuit 92, etc.

[0082] In a possible design, the acquisition circuit 91 includes: an attitude module, a conversion module, a main control module, a 4-channel acquisition module, a data transmission module, a data storage module, and a clock synchronization module;

[0083] The attitude module is used to obtain the azimuth state, the conversion module is used to convert the electric energy provided by the power supply 8, the main control module is used to achieve clock frequency division, clock synchronization for underwater positioning, switching control of node test items, digital signal acquisition control, and analog signal output control, the 4-channel acquisition module is used to acquire the data measured by the piezoelectric detector 4 and the three-component detector 6, the data transmission module is used to transmit data outward, the data storage module is used to store data, and the clock synchronization module is used to achieve 4-channel data acquisition synchronization and precise data acquisition synchronization between nodes.

[0084] Based on the acquisition circuit 91, the device realizes the automatic acquisition of submarine seismic data, enabling the device to operate independently on the seabed without being controlled by the host system, reducing the impacts such as high noise, low system sensitivity, blurred drift imaging, presence of ghost waves, and poor quality of seismic data brought by the use of cables during the detection process, and also reducing costs.

[0085] In a possible design, the attitude module includes: an attitude sensor electrically coupled to the main control module; the attitude sensor can record the corresponding heading angle, pitch angle, and roll angle.

[0086] Among them, generally, the right, front, and up directions of the carrier form a right-handed system. Rotation around the forward axis is the roll angle, rotation around the right axis is the pitch angle, and rotation around the up axis is the heading angle.

[0087] Since the seabed is uneven, the attitude sensor can judge the placement azimuth state of the device. According to the signals collected by each detector and the attitude information of the attitude sensor, the seismic signals will be projected onto the X, Y, and Z directions for processing in the subsequent data stacking process.

[0088] In this device, the conversion module includes a DC (Direct Current) converter. The power supply 8 provides electrical energy for the conversion module in the acquisition circuit 91. The voltage range of this power supply 8 is 9V - 18V. The voltage is converted to ±5V through the DC converter, so as to provide electrical energy for other parts in the acquisition circuit 91.

[0089] The main control module can achieve high-precision clock frequency division, PPS (Pulse Per Second) synchronization of GPS (Global Positioning System), node test item switching control, AD (analog to digital) acquisition control, and DA (digital to analog) output control. The main control module can use an STM32 type embedded single-chip microcomputer to achieve the interface control of the SD card and the network interface control of 10M / 100M. The FPGA (Field Programmable Gate Array, a programmable device) provides analog board control signals (AD and DA control), interface signals, and clock signals for the data acquisition module, and realizes data communication with the STM32 processor based on the FSMC (Flexible Static Memory Controller) interface.

[0090] The 4-channel acquisition module uses a high-performance and high-precision Δ-Σ AD chip dedicated for seismic geophysical prospecting. The sampled input voltage is between ±2.5V. The output signal and the control signal are connected to the FPGA through SPI (Serial Peripheral Interface). Four sampling rates of 0.25ms, 0.5ms, 1ms, and 2ms, and preamplifier gains of 0dB, 12dB, 24dB, and 36dB can be set. The filtering method can be selected from linear phase and minimum phase.

[0091] Data transmission module: There is 1 LAN (Local Area Network) interface on the control board. This data transmission module connects this LAN to the external socket 7. After the device is lifted out of the water surface, it is connected to the upper computer through this connection socket. The upper computer realizes the download of data files of multiple nodes through the network according to a custom protocol.

[0092] The data storage module includes an SD (Secure Digital) card, which is used to realize the read and write access of high-capacity SD memory cards. When working, the collected data is stored in the SD card in the form of FAT (File Allocation Table). The storage duration of each file can be set to every hour, every 2 hours, every 4 hours, every 8 hours, every 12 hours or every 24 hours (the time length of a data file). The supported data acquisition time is 30 days @ 2ms, that is, when the sampling rate is 2ms, the battery in the device can supply power to the system for 30 days.

[0093] The function of the clock synchronization module is: through the second pulse (PPS) input by the external initial GPS and based on the internal high-precision clock, to realize the synchronization of 4-channel data acquisition within the node and the precise data acquisition synchronization between nodes. The synchronization accuracy is controlled within 2 milliseconds during continuous operation for 30 days.

[0094] In a possible design, at least one handle 21 is provided at the end of the pressure-resistant inner shell 2, which facilitates the operation of retracting and releasing the hook, reduces the vibration wave transmitted from the main cable to the node station body, and thus minimizes the noise. Further, the handle 21 is square, and the number is two, which are respectively arranged at each end and located between the two pressure-bearing end caps 3, facilitating the operation of retracting and releasing the hook, reducing the vibration wave transmitted from the main cable to the node station body, and reducing the underwater acquisition noise.

[0095] All the above optional technical solutions can be combined arbitrarily to form the optional embodiments of the present application, which will not be elaborated one by one here.

[0096] Taking the design process of one such device as an example, the present application will be further described in detail.

[0097] (1) Design the circuit board

[0098] First, according to the needs of the underwater acquisition system, design the circuit and power supply. The number of channels is determined according to the signal variables to be collected. For marine seismic exploration, it is necessary to collect the signals of piezoelectric detectors and 3 three-component detectors 6, so 4 channels are set for acquisition. The attitude sensor records the heading, pitch, and roll angles of the device, and can perform vector rotation on the data of the 3 three-component detectors 6 inside the device to obtain the actual vertical and horizontal component data. Generally, it is required that the heading error is less than 2°, and the measurement errors of pitch and roll angles are less than 0.4°. The internal high-precision clock is very crucial, and the required accuracy is 10 -10For more than [X] seconds, it realizes the synchronization of 4-channel data acquisition within nodes and the precise data acquisition synchronization between nodes. The synchronization accuracy is controlled within 2 milliseconds during continuous operation for 30 days. The acoustic circuit amplifies, discriminates the frequency, and processes the signals received by the acoustic transducer 5 to realize the recognition of specific acoustic signals, and sends the electrical signals of a fixed frequency to the acoustic transducer 5 for transmission, realizing the acoustic positioning of the subsea node.

[0099] Design the circuit board and battery according to the above functions.

[0100] (2) Design the sensor

[0101] The sensors of this device include 1 piezoelectric geophone 4, 3 three-component geophones 6, and 1 acoustic transducer 5. The piezoelectric geophone 4 and the acoustic transducer 5 should meet the watertight requirements and pressure-bearing requirements for underwater operation. Generally, it is required that the sensitivity of the piezoelectric geophone 4 is not less than -201 dB at the required working water depth, the sensitivity of the three-component geophone 6 is not less than 22.4 V / m / s, and the acoustic transducer 5 is designed according to the performance of the entire system.

[0102] (3) Mechanical housing

[0103] Design the mechanical shape according to the circuit, battery, and sensors. During the design of the housing, design the pressure-resistant level according to the working water depth. A particularly crucial point is to pay attention to the coupling of this device with the seabed. Design two rows of grounding wedge feet on the outer housing so that this device has good gripping ability on the seabed and good coupling effect. At the same time, the upper wedge foot 14 and the lower wedge foot 13 can bite each other, which is convenient for stable stacking and also saves space. It is also necessary to design the handle 21 of this device for convenient hanging on the cable.

[0104] (4) Installation and testing

[0105] Assemble the above components, test parameters such as the noise, distortion, and common-mode consistency ratio of the system to meet the requirements, and test the acoustic performance and watertight performance of this device. Finally, conduct a knocking test to verify that the clock drift is within the specified range.

[0106] Complete the production of the entire device.

[0107] The device provided by the embodiment of the present application is provided with a pressure-resistant inner housing 2 with a pressure-bearing end cover 3, which facilitates fixing the piezoelectric geophone 4 and the acoustic transducer 5 on the pressure-bearing end cover 3. Inside the pressure-resistant inner housing 2, there are a three-component geophone 6, a power supply 8, and a circuit unit 9. Among them, the circuit unit 9 is used to control the piezoelectric geophone 4 to detect the seismic longitudinal wave pressure in seawater, control the three-component geophone 6 to pick up the submarine seismic signal, and control the acoustic transducer 5 for submarine positioning. The power supply 8 is used to provide electrical energy for other components in the device. An outer housing 1 is covered outside the pressure-resistant inner housing 2. The outer housing 1 can not only protect the pressure-resistant inner housing 2, the piezoelectric geophone 4, the acoustic transducer 5, and the external socket 7, but also be better fixed on the seabed through the lower wedge feet 13 at the bottom. After the device is placed on the seabed, the device can independently perform detection work as a single node. The data stored in the acquisition circuit 91 in the device can be exported through the external socket 7 at regular intervals. Through this device, the seismic data corresponding to the 4 acquisition channels measured by the piezoelectric geophone 4 and the three-component geophone 6 can be obtained. Since there is no need to use a transmission cable to transmit data to the host system in real time, the cost is relatively low.

[0108] Further, based on the acquisition circuit 91, the device realizes the automatic acquisition of submarine seismic data, enabling the device to operate independently on the seabed without being controlled by the host system, reducing the impacts such as high noise, low system sensitivity, blurred drift imaging, ghost waves, and poor seismic data quality brought by the use of cables during the detection process, and also reducing costs.

[0109] The device can automatically collect and store seismic data. Multiple such devices can be connected by a rope of a certain length to form a node acquisition chain. It is not only free from the bondage of cables, has high flexibility, but also is more convenient for system deployment and recovery. The device has more accurate positioning and higher-quality collected data. The device has outstanding advantages such as being unrestricted by the number of channels, simple composition, convenient construction, and environmental protection. It can obtain omnidirectional and fidelity data, improve seismic imaging quality, improve the repeatability of 4D exploration, and improve the results of reservoir monitoring. The acoustic acquisition is integrated, and no external transponder is required for positioning, which is convenient for construction.

[0110] The above are only optional embodiments of the present application and are not intended to limit the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. An ocean seismic node acquisition device, characterized in that, The device includes: an outer housing (1), a pressure-resistant inner housing (2), at least two pressure-bearing end caps (3), a piezoelectric detector (4), an acoustic transducer (5), a three-component detector (6), an external socket (7), a power supply (8), and a circuit unit (9); The outer housing (1) includes an upper housing (11) and a lower housing (12). The upper housing (11) and the lower housing (12) are snapped and wrapped outside the pressure-resistant inner housing (2), and the upper housing (11) and the lower housing (12) are detachably connected. Multiple pairs of lower wedge feet (13) arranged axially are provided at the bottom of the lower housing (12), and serrated patterns are provided on the bottom surfaces of each pair of the lower wedge feet (13); An accommodation chamber is provided inside the pressure-resistant inner housing (2). Each port of the pressure-resistant inner housing (2) is hermetically connected to at least one of the pressure-bearing end caps (3). The piezoelectric detector (4), the acoustic transducer (5), and the external socket (7) are respectively fixed on the outer end faces of the at least two pressure-bearing end caps (3), and the piezoelectric detector (4), the acoustic transducer (5), and the external socket (7) are all located inside the outer housing (1); A power supply (8), a circuit unit (9), and a three-component detector (6) are provided in the accommodation chamber. The power supply (8) and the circuit unit (9) are both electrically coupled to the external socket (7); The circuit unit (9) includes an acquisition circuit (91) and an acoustic circuit (92). The power supply (8), the acquisition circuit (91), and the piezoelectric detector (4) are electrically coupled in sequence. The power supply (8), the acquisition circuit (91), and the three-component detector (6) are electrically coupled in sequence. The acquisition circuit (91) can process and store the data measured by the piezoelectric detector (4) and the three-component detector (6). The power supply (8), the acoustic circuit (92), and the acoustic transducer (5) are electrically coupled in sequence. The acoustic circuit (92) and the acoustic transducer (5) are used for seabed positioning.

2. The device according to claim 1, wherein Multiple pairs of upper wedge feet (14) arranged axially are provided on the top surface of the upper housing (11), and each pair of upper wedge feet (14) can be clamped inside a pair of lower wedge feet (13).

3. The device according to claim 1, characterized in that, The connection between the upper housing (11) and the lower housing (12) is fixed by a connection bolt (15); The middle part of the upper housing (11) and the lower housing (12) is fixed to the pressure-resistant inner housing (2) by a fastening bolt (16).

4. The device according to claim 1, characterized in that, The material of the outer housing (1) is nylon 66.

5. The device according to claim 1, wherein The upper housing (11) includes multiple upper sub-sections (111), and the lower housing (12) also includes multiple lower sub-sections (121) corresponding to the upper sub-sections (111).

6. The device according to claim 1, characterized in that, The pressure-resistant inner housing (2) includes two circular tubes, and the connection between the two circular tubes is communicated. One circular tube is used to accommodate the power supply (8), and the other circular tube is used to accommodate the circuit unit (9) and the three-component detector (6); The number of the pressure-bearing end caps (3) is four, and each end of each circular tube is connected to a pressure-bearing end cap (3).

7. The device according to claim 1, characterized in that, A protective shell (51) is provided on the acoustic transducer (5).

8. The device according to claim 1, characterized in that, The acquisition circuit (91) includes: an attitude module, a conversion module, a main control module, a 4-channel acquisition module, a data transmission module, a data storage module, and a clock synchronization module; The attitude module is used to obtain the azimuth state, the conversion module is used to convert the electric energy provided by the power supply (8), the main control module is used to achieve clock frequency division, clock synchronization for seabed positioning, switching control of node test items, digital signal acquisition control, and analog signal output control, the 4-channel acquisition module is used to acquire the data measured by the piezoelectric detector (4) and the three-component detector (6), the data transmission module is used to transmit data outward, the data storage module is used to store data, and the clock synchronization module is used to achieve 4-channel data acquisition synchronization and precise data acquisition synchronization between nodes.

9. The device according to claim 8, characterized in that, The attitude module includes: an attitude sensor, electrically coupled to the main control module; The attitude sensor can record the corresponding heading angle, pitch angle, and roll angle.

10. The device according to claim 1, characterized in that, At least one handle (21) is provided at the end of the pressure-resistant inner shell (2).

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