Intelligent positioning device, seismic acquisition system and method

Abstract

The application provides an intelligent positioning device, a seismic acquisition system and a method, and belongs to the field of seismic exploration. The intelligent positioning device comprises a main controller and a communication module, an input module, a positioning satellite receiving module and a vibration signal generating module connected to the main controller respectively; an antenna is connected to the positioning satellite receiving module; and a vibration module is connected to the vibration signal generating module. The application can position all observation points before acquisition to obtain the correspondence between the observation points and the sampling points, can obtain the position information and the stake number information of the observation points by analyzing the received information during the acquisition process, and can determine the sampling data of the observation points by using the correspondence between the observation points and the sampling points, so that the one-to-one correspondence between the recorded data and the actual observation points is ensured, and the positioning problem of the distributed acoustic sensing system (DAS) is solved.

Description

Technical Field

[0001] This invention belongs to the field of seismic exploration, specifically relating to an intelligent positioning device, a seismic acquisition system and method, mainly used for land seismic exploration and monitoring. Background Technology

[0002] Since the application of seismic exploration technology in the 1930s, seismic exploration has been a primary technical means for finding minerals such as oil and coal in fields such as petroleum and coal. In the nearly 100-year development of seismic geophysical exploration technology, seismic acquisition equipment has been the key equipment, complementing the development of seismic geophysical exploration technology. Its technical level, performance indicators, and application effects are all directly related to the quality of seismic acquisition data.

[0003] After nearly a century of development, mainstream seismic acquisition systems have evolved into two main forms: wired and nodal. However, the sensors used to receive seismic signals and the observation systems remain the same. The two acquisition systems are described below. Figure 1 As shown in Figure 2.

[0004] Land wired seismic acquisition systems such as Figure 1 As shown, the details are as follows:

[0005] The current wired seismic acquisition system used on land mainly includes a central control server M01, acquisition station M02, management station M03, data transmission cable M04, and communication cable M05. Different devices in the system are connected and communicate with each other through different cables, and the system status and data recovery can be viewed in real time.

[0006] The central control server M01 is the core of the system. It runs the system monitoring program, monitors the system's operating status, collects data, and stores and displays it.

[0007] Acquisition station M02 connects to the seismic detector, converting analog signals into digital signals; however, acquisition station M02 generally does not contain a seismic detector. It connects to management station M03 via data transmission cable M04, receiving control commands and transmitting acquired data to management station M03. Acquisition station M02 also functions as a relay, connecting the next-level acquisition station M02 with the previous-level acquisition station M02 or management station M03.

[0008] Management station M03 is an intermediate management unit that communicates with the central control server M01 via communication cable M05 and with the data acquisition station M02 via data transmission cable M04. It manages the data acquisition station, collects and stores the collected data, and uploads it. Management station M03 also has a relay function, connecting the next-level management station M03 with the previous-level management station M03 or the central control server M01.

[0009] Data transmission cable M04 is the cable connecting acquisition station M02 to acquisition station M02, and between acquisition station M02 and management station M03. It is generally composed of multi-core copper cable.

[0010] Communication cable M05 is the cable connecting management stations M03 and the central control server M01 of management station M03, and is generally composed of optical fiber.

[0011] The central control server M01 is usually placed indoors, while the management station M03 and the data acquisition station M02 are placed outdoors in an array. The data acquisition station M02 corresponds one-to-one with the station number in the array.

[0012] Land-based nodal seismic acquisition systems, such as Figure 2-1 and Figure 2-2 As shown, the details are as follows:

[0013] A land-based nodal seismic acquisition system mainly consists of a central control server M01, acquisition unit controllers M06, and acquisition stations M02. The central control server M01 and acquisition unit controllers M06 are typically located indoors, while acquisition stations M02 are placed on a grid. During normal acquisition, the central control server M01, acquisition unit controllers M06, and acquisition stations M02 do not communicate with each other, making real-time monitoring and data transmission impossible. Data acquired by acquisition station M02 requires specialized data retrieval.

[0014] The central control server M01 is the core of the system. It runs the system monitoring program and manages the acquisition station M02 through the acquisition unit controller M06, setting parameters, reading status and collecting data.

[0015] The data acquisition unit controller M06 is a dedicated device that connects the central control server M01 and the data acquisition station M02, and performs the transmission of control commands and the reading, storage and transmission of data.

[0016] The acquisition station M02 is directly deployed on the sampling points of the receiving array to receive vibration signals, convert analog signals into digital signals, and store them.

[0017] The main advantages and disadvantages of wired seismic acquisition systems and nodal seismic acquisition systems on land are as follows:

[0018] Land-based wired seismic acquisition systems can monitor system operation status and data transmission in real time, but they have high requirements for data transmission technology and their transmission capacity is limited.

[0019] Land-based nodal seismic acquisition systems are easy to use, but they cannot monitor the status of the acquisition stations in real time, and power supply and data recovery affect the application of the system.

[0020] With the changing objectives of exploration and development, seismic geophysical exploration technology has also developed in different directions, leading to significant changes in the requirements for seismic acquisition equipment receiving systems. In the past decade, with the development of fiber optic modulation and demodulation technology, distributed fiber acoustic sensing (DAS) has shown promising application prospects in seismic exploration.

[0021] Distributed fiber acoustic sensing (DAS) technology uses the phase of coherent Rayleigh scattered light, rather than its intensity, to detect signals such as sound or vibration within the audio range. It can not only use the magnitude of the phase amplitude to provide intensity information of sound or vibration events, but also use linear quantitative measurements to obtain phase and frequency information of sound or vibration events.

[0022] The DAS measurement process is as follows: A laser emits light pulses along an optical fiber. Some of the light interferes with the incident light within the pulse in the form of backscattering. After the interfering light is reflected back, the backscattered interference light returns to the signal processing device, simultaneously transmitting the acoustic vibration signal along the optical fiber to the signal processing device. Since the speed of light remains constant, the measurement result of the acoustic vibration per meter of optical fiber can be obtained. DAS can be applied to fields such as oil exploration and monitoring of acoustic vibration processes during oil and shale gas fracturing.

[0023] To facilitate understanding of the positioning device's operation, the data acquisition workflow of the seismic exploration and terrestrial distributed fiber optic acoustic wave sensing seismic acquisition system (DAS) will be briefly described below.

[0024] Seismic exploration process: Before seismic exploration fieldwork, an observation system design is required. The observation system designer determines the corresponding technical parameters based on the exploration objectives, calculating the size and boundaries of the exploration area, as well as the number, distribution, and extent of observation points. A typical layout for three-dimensional exploration observation points is as follows: Figure 1 The field deployment of acquisition stations in a land-based wired seismic acquisition system is shown. Figure 1 Each acquisition station M02 corresponds to an observation point. Each observation point is equipped with a set of detectors, which are used by the acquisition station to collect data.

[0025] Before construction, professional surveying is required to determine the specific locations of observation points based on the observation system, and these points are numbered; these numbers become the station numbers. During actual construction, a set of seismic detectors is installed at each station number.

[0026] In traditional data acquisition, since the positions of each seismic detector are fixed, the data at the sampling points are only related to the position of the seismic detectors and not to the connection method between the acquisition stations. Therefore, there is no problem in locating the sampling points and observation points.

[0027] The locations of the sample points in a terrestrial distributed fiber optic acoustic wave sensing seismic acquisition system cannot form an intuitive correspondence, mainly for the following reasons:

[0028] The location of the fiber optic sampling point is directly related to the fiber optic length between the sampling point and the reference point. However, due to changes in the terrain and obstacles such as roads, the fiber optic cable cannot be laid out completely horizontally and at equal intervals during the deployment process. Therefore, the location of the sampling point and the observation point cannot be directly correlated.

[0029] In summary, current technologies cannot pinpoint the location of DAS sampling points. Existing DAS positioning technologies primarily target optical fibers laid on surfaces such as straight lines, circles, and regular curves. The lengths from each observation point to the light source and modem can be directly calculated, and the location of the observation point is determined by the lengths from the sampling point to the light source and modem. However, in seismic exploration, optical fibers are buried in trenches dug along the ground in a specific direction. Due to the uneven terrain and lack of fixed curves, the exact lengths from the observation point to the light source and modem cannot be predetermined, thus making it impossible to determine the specific location of the observation point based on the sampling points. Summary of the Invention

[0030] The purpose of this invention is to solve the problems existing in the prior art and provide an intelligent positioning device, seismic acquisition system and method, which provides the positioning of observation points for distributed fiber optic acoustic sensing technology in land exploration acquisition systems, solves the problem of the correspondence between sampling points and observation points, i.e. the positioning problem, and thus ensures the accurate location of sampling points and improves exploration accuracy.

[0031] This invention is achieved through the following technical solution:

[0032] In a first aspect, the present invention provides an intelligent positioning device, the intelligent positioning device comprising: a main controller and a communication module, an input module, a positioning satellite receiving module, and a vibration signal generating module respectively connected thereto;

[0033] An antenna is connected to the positioning satellite receiving module;

[0034] A vibration module is connected to the vibration signal generation module.

[0035] A further improvement of the present invention is that:

[0036] The vibration module includes: a fixed component and a vibration component;

[0037] The fixing component includes two clamping blocks;

[0038] Each clamping block is a cuboid structure with a through semi-cylindrical groove on one side. Threaded holes are provided on both sides of the cuboid structure. The central axis of the threaded holes is perpendicular to the central axis of the semi-cylindrical groove.

[0039] A mounting groove is provided on one side of one of the clamping blocks, and the vibrating component is disposed in the mounting groove.

[0040] A further improvement of the present invention is that:

[0041] After the two clamping blocks are placed symmetrically, the threaded holes on both sides of the two clamping blocks are aligned. Bolts are inserted into the threaded holes on both sides and fixed with nuts. The semi-cylindrical grooves on the two clamping blocks form a cylindrical hole.

[0042] In a second aspect, the present invention provides an earthquake acquisition system, the earthquake acquisition system comprising: a system controller, a light source modulator, an optical fiber signal demodulator, an optical fiber interface module, a vibration detection optical fiber, and a main communication module;

[0043] The light source modulator, fiber optic signal demodulator, and fiber optic interface module are respectively connected to the system controller. At the same time, the light source modulator and fiber optic signal demodulator are respectively connected to the fiber optic interface module, and multiple vibration detection fibers are respectively connected to the fiber optic interface module.

[0044] The aforementioned intelligent control device is provided in one or more of the vibration detection optical fibers;

[0045] The intelligent positioning device communicates with the system controller through a communication module and a main communication module.

[0046] A third aspect of the present invention provides a seismic acquisition method, wherein the method is implemented using the aforementioned seismic acquisition system; the method first locates all observation points before acquiring data to obtain the correspondence between observation points and sampling points; during the data acquisition process, the sampling data is reconstructed using the correspondence between observation points and sampling points to obtain data files that correspond one-to-one with the observation points.

[0047] A further improvement of the present invention is that the operation of locating all observation points before collecting data includes:

[0048] The vibration module of the intelligent positioning device is fixed to the vibration detection optical fiber, and then the intelligent positioning device runs the following program:

[0049] (11) Power-on initialization;

[0050] (12) Receive input information from the input module. The input information includes: the geographical coordinates of the observation point where the intelligent positioning device is located, the station number in the arrangement, the time when the vibration signal generation module generates the corresponding signal and sends the vibration signal, and the frequency and amplitude of the generated vibration signal.

[0051] (13) Determine whether the information input is complete. If not, return to step (12). If yes, proceed to step (14).

[0052] (14) Determine if it is time to send a vibration signal. If not, return to step (14). If yes, proceed to step (15).

[0053] (15) Generating vibration signals: The main controller sends a vibration signal command to the vibration signal generation module. After receiving the vibration signal command, the vibration signal generation module generates an electrical signal. After receiving the electrical signal, the vibration module starts to vibrate and generates a vibration signal.

[0054] (16) Determine whether the positioning of this observation point has ended. If not, return to step (14). If yes, return to step (12) to perform the positioning of the next observation point until the positioning of all observation points is completed.

[0055] A further improvement of the present invention is that:

[0056] The operation of obtaining the correspondence between observation points and sampling points includes:

[0057] After the seismic acquisition system completes all physical connections and is able to acquire data normally, the system controller in the seismic acquisition system runs the following program:

[0058] (21) Perform positioning initialization;

[0059] (22) Collect data once;

[0060] (23) Analyze whether the collected data contains location information. If yes, proceed to step (24); otherwise, proceed to step (26).

[0061] (24) Use the location information to determine the sampling point corresponding to the observation point;

[0062] (25) Establish a table of correspondence between sampling points and observation points: fill in the serial number of the observation point and the serial number of the corresponding sampling point into the table of correspondence between sampling points and observation points;

[0063] (26) Determine whether the positioning has ended. If not, return to step (22). If yes, proceed to step (27).

[0064] (27) Generate a table of correspondence between sampling points and observation points;

[0065] (28) Return to the previous program.

[0066] A further improvement of the present invention is that:

[0067] The operation of step (24) includes: reading the positioning information of the sampling points; when the positioning information of multiple consecutive sampling points is the same, selecting the sampling point with the largest amplitude among these sampling points as the sampling point corresponding to the observation point.

[0068] A further improvement of the present invention is that the operation of reconstructing the sampled data using the correspondence between observation points and sampling points during the data acquisition process to obtain a data file corresponding one-to-one with the observation points includes:

[0069] The system controller in the seismic acquisition system runs the following program:

[0070] (31), data acquisition initialization;

[0071] (32) Collect data once;

[0072] (33) Read the table of correspondence between sampling points and observation points;

[0073] (34) Reconstruct the collected data file.

[0074] A further improvement of the present invention is that:

[0075] The operation of step (34) includes: retaining the data of the sampling points corresponding to the observation points, deleting the data of the sampling points that do not correspond to the observation points, regenerating the data files that correspond one-to-one with the observation points, and storing them in the standard format of seismic exploration.

[0076] A fourth aspect of the present invention provides a computer-readable storage medium storing at least one computer-executable program, which, when executed by the computer, causes the computer to perform the steps in the above-described seismic acquisition method.

[0077] Compared with the prior art, the beneficial effects of the present invention are:

[0078] This invention enables the location of all observation points before data acquisition to obtain the correspondence between observation points and sampling points. During the acquisition process, the location and station information of the observation points can be obtained by analyzing the received information. By using the correspondence between observation points and sampling points, the sampling data of the observation points can be determined, ensuring a one-to-one correspondence between the recorded data and the actual observation points. This solves the positioning problem of distributed optical fiber acoustic wave sensing system (DAS). Attached Figure Description

[0079] Figure 1Schematic diagram of an existing land-based wired seismic acquisition system;

[0080] Figure 2-1 Schematic diagram of an existing land-based nodal seismic acquisition system;

[0081] Figure 2-2 Schematic diagram of the field deployment of existing land-based nodal seismic acquisition systems;

[0082] Figure 3 Functional block diagram of a terrestrial distributed fiber optic acoustic wave sensing seismic acquisition system (DAS);

[0083] Figure 4 Functional block diagram of the intelligent positioning device of the present invention;

[0084] Figure 5 Block diagram of single optical fiber positioning in this invention;

[0085] Figure 6 Workflow diagram of the intelligent positioning device of this invention;

[0086] Figure 7 Flowchart of the main controller positioning subroutine of this invention;

[0087] Figure 8 Flowchart of the main controller data acquisition subroutine of this invention;

[0088] Figure 9 A top view of the vibration module in the intelligent positioning device of this invention. Detailed Implementation

[0089] The present invention will now be described in further detail with reference to the accompanying drawings:

[0090] Land-based distributed fiber optic acoustic sensing seismic acquisition system (DAS) such as Figure 3 As shown, according to functional division, the terrestrial distributed optical fiber acoustic wave sensing seismic acquisition system (DAS) includes: system controller M1, light source generator modulator M2, optical fiber signal demodulator M3, optical fiber interface module M4, vibration detection optical fiber M5, and main communication module M6. System controller M1, light source generator modulator M2, optical fiber signal demodulator M3, optical fiber interface module M4, vibration detection optical fiber M5, and main communication module M6 are all modules already present in existing DAS systems.

[0091] Specifically, the light source modulator M2, the fiber optic signal demodulator M3, and the fiber optic interface module M4 are respectively connected to the system controller M1. At the same time, the light source modulator M2 and the fiber optic signal demodulator M3 are respectively connected to the fiber optic interface module M4, and multiple vibration detection fibers M5 are respectively connected to the fiber optic interface module M4.

[0092] This invention provides a data acquisition system, and embodiments of the data acquisition system are as follows:

[0093] Example 1

[0094] This invention adds multiple intelligent positioning devices M7 to the existing DAS system. Specifically, intelligent positioning devices M7 are installed on one or more vibration detection optical fibers M5. The intelligent positioning devices M7 generate controllable vibration signals, which are controlled by the system controller M1 to establish the correspondence between observation points and sampling points. Then, based on the correspondence, the observation point data is reconstructed to generate the collected data file.

[0095] The system controller M1 is the core of the DAS system, running core programs such as system monitoring, providing human-machine interaction information, controlling the light source modulator M2, receiving data from the fiber optic demodulator M3, processing it, storing the data, and displaying it according to settings; controlling the fiber optic interface module M4 to transmit the optical signal generated by the light source modulator M2 to the corresponding optical fiber; communicating with the main communication module M6 to monitor the intelligent positioning device M7, determining the position of the intelligent positioning device M7 and its corresponding station number within the arrangement, and calculating the sampling point corresponding to the intelligent positioning device for position correction of the sampling data.

[0096] The light source modulator M2 is a light source generator that receives instructions from the system controller M1 to generate light signals with different periods and intensities. Currently, lasers are generally used as the light source, and the intensity of the excitation light source is adjusted according to the intensity of the received signal.

[0097] The fiber optic signal demodulator M3 receives the optical signal transmitted from the fiber optic interface module M4. Based on the principle that the speed of light remains constant during transmission in the optical fiber, it determines the magnitude and phase of the vibration signal at the reflection position by measuring the phase of the reflected light at different times, and transmits the data to the system controller M1 for processing and storage.

[0098] The fiber optic interface module M4 is directly connected to the system controller M1, the light source modulator M2, the optical signal demodulator M3, and the optical fiber M5. The fiber optic interface module M4 receives instructions from the system controller M1, transmits the optical signal generated by the light source modulator M2 to the corresponding optical fiber M5, and sends the reflected signal from the corresponding optical fiber M5 to the optical signal demodulator M3 for processing.

[0099] The vibration detection fiber M5 is an optical fiber manufactured according to the detection needs. It is buried along the observation line according to the design of the exploration and observation system and is used to detect vibration signals at the observation points.

[0100] The main communication module M6 communicates with the system controller M1, receiving instructions from the system controller M1 to control the corresponding intelligent positioning device M7 to generate vibration signals of a certain frequency and amplitude. The main communication module M6 and the intelligent positioning device M7 can be connected via wired or wireless means.

[0101] The intelligent positioning device M7 communicates with the system controller M1 through the main communication module M6. Based on the instructions of the system controller M1 or pre-set parameters, it generates vibration signals of a certain frequency and amplitude. These vibration signals are transmitted to the vibration detector M5 connected to the intelligent positioning device M7 to measure the contact position.

[0102] The present invention also provides an intelligent positioning device, an embodiment of which is as follows:

[0103]

Example 2

[0104] Specifically, the structure of the intelligent positioning device M7 designed in this invention is as follows: Figure 4 As shown, it includes: a main controller M71 and a communication module M72, an input module M73, a positioning satellite receiving module M74, and a vibration signal generating module M76 connected thereto. An antenna M75 is connected to the positioning satellite receiving module M74, and a vibration module M77 is connected to the vibration signal generating module M76.

[0105] The specific modules are as follows:

[0106] The main controller M71 is the control center of the intelligent positioning device M7. It communicates with the system controller M1 through the communication module M72 and the main communication module M6; it performs local human-machine interaction through the input module M73 to input commands and information; it receives satellite information through the positioning satellite receiving module M74 to read the time and the location information of the observation point; it sends control information to the vibration signal generation module M76, which generates an electrical signal of a certain frequency and amplitude and amplifies it. The vibration signal generation module generates an electrical signal, which is then converted into mechanical vibration by the vibration module.

[0107] The communication module M72 uses hardware interface circuits with multiple communication methods such as wired and wireless, and can connect, communicate and exchange information with the main communication module M6 through wired or wireless means.

[0108] Input module M73 is the interface module for local information input by the intelligent positioning device M7. It includes wireless and wired communication interface circuits, allowing information to be input locally via wireless or wired methods. Various existing input modules can be used. Input information includes the coordinates of the observation point where the intelligent positioning device M7 is located, its station number in the array, and various parameters such as the time when the vibration signal generation module M76 generates the corresponding signal and the start time of vibration signal generation.

[0109] The positioning satellite receiver module M74 receives satellite signals through antenna M75, identifies and processes the received signals, generates comprehensive information including position coordinates, time, and pulse-per-second (PPS), and transmits it to the main controller M71. The positioning satellite receiver module M74 employs multiple satellite receiver modules such as BeiDou and GPS, enabling it to receive information from different positioning systems.

[0110] Antenna M75 receives wireless signals, amplifies them initially, and then transmits them to the positioning satellite receiving module M74.

[0111] The vibration signal generation module M76 receives instructions from the main controller M71 and generates an electrical signal of a certain frequency and amplitude at a specified time. Existing vibration signal generation modules can be used.

[0112]

Example 3

[0113] The vibration module M77 designed in this invention has the function of converting electrical signals into vibration signals and fixing them on optical fibers. Its structure is as follows: Figure 9 As shown, the device includes a fixing component and a vibrating component. The fixing component includes two clamping blocks M771, each of which is a cuboid structure. A through semi-cylindrical groove M774 is formed on one side of each clamping block M771. Threaded holes M772 are provided on both sides of the cuboid structure, with the central axis of the threaded holes M772 perpendicular to the central axis of the semi-cylindrical groove M774. A mounting groove M773 is formed on one side of one of the clamping blocks M771, and the vibrating component is installed in the mounting groove M773. After the two clamping blocks M771 are placed symmetrically, the threaded holes M772 on both sides of the two clamping blocks M771 are aligned. Bolts are inserted into the threaded holes on both sides and secured with nuts. The semi-cylindrical grooves on the two clamping blocks M771 form a cylindrical hole. The diameter of the semi-cylindrical groove M774 is designed according to the diameter of the optical fiber. Various sizes of fixing components can be designed. The diameters of the semi-cylindrical grooves and threaded holes on different fixing components are different, making them suitable for optical fibers of different thicknesses.

[0114] During installation, two clamping blocks M771 are placed opposite each other on both sides of the optical fiber, allowing the fiber to pass through the semi-cylindrical groove. Bolts are inserted into the threaded holes on both sides, and after securing with nuts, the two clamping blocks M771 clamp the optical fiber, which then passes through the cylindrical hole. This fixes the vibrating component to the optical fiber. The vibrating component is a vibration circuit board, which can be any existing product, such as piezoelectric elements, and will not be elaborated upon here. After the vibration module M77 is fixed to the optical fiber, the vibration signal generated by the module is transmitted to the optical fiber M5, which can then detect the vibration signal.

[0115] In practical use, the positioning on a single fiber M5 is as follows: Figure 5 As shown, based on the needs of the exploration target, three-dimensional seismic exploration is now generally carried out, and the setting of field observation points is as follows: Figure 1 As shown in the schematic diagram of the field deployment of the acquisition station, the fiber optic deployment of the terrestrial distributed optical fiber acoustic wave sensing seismic acquisition system (DAS) is also based on this scheme. The difference is that the optical fiber is buried along the survey line, and there is no need to deploy seismic detectors separately.

[0116] Figure 5 The illustrated embodiment uses the m-th survey line with n observation points as an example to illustrate the deployment method of the intelligent positioning device, as detailed below:

[0117] like Figure 5 As shown, the first observation point of the m-th survey line is denoted as LmR1, the second observation point as LmR2, and so on, with the n-th observation point denoted as LmRn.

[0118] A smart positioning device M7 is set up at each observation point to generate one or more vibration signals containing observation point information, either remotely or periodically, according to remote commands or pre-set parameters.

[0119] Using the aforementioned intelligent positioning device M7, this invention solves the problem of the correspondence between sampling points and observation points, i.e., the positioning problem. The method first positions all observation points before collecting data to obtain the correspondence between observation points and sampling points. During the data collection process, the corresponding relationship between observation points and sampling points is used to reconstruct the sampling data to obtain a data file that corresponds one-to-one with the observation points.

[0120] An embodiment of the method is as follows:

[0121]

Example 4

[0122] For simplicity, we will use a laser as an example for explanation.

[0123] The working principle of the existing ADS system is as follows:

[0124] First, the system controller M1 sends a data acquisition command to the light source modulator M2. The light source modulator M2 periodically generates laser pulse signals (hereinafter referred to as optical pulses) of fixed width and amplitude at certain intervals within a pre-set time period. The optical pulses are transmitted to the corresponding optical fiber via the optical fiber interface module M4 and propagate along the optical fiber. Due to the non-uniformity of the optical fiber, some of the light will be reflected back when the transmission medium changes.

[0125] During the transmission of an optical pulse on an optical fiber, when it is subjected to external forces, it will stretch and compress, causing changes in the reflected optical signal.

[0126] After each light pulse emitted by the light source modulator M2, a certain delay is made, and the system controller M1 sends a command to the fiber optic interface module M4 to connect the fiber optic cable to the optical signal demodulator M3. The demodulator M3 then collects and preprocesses the fiber optic signal and sends it to the system controller M1. The system controller M1 performs noise reduction, filtering, and other processing on the data and generates a standard data file according to the seismic exploration standards and file format for storage.

[0127] At this point, the ADS system has completed one seismic data acquisition.

[0128] In this invention, a sampling point refers to its location on an optical fiber. For example, if the sampling interval of a DAS system is set to 2 meters, then the first sampling point represents a distance of 2 meters from the reference point, and the nth sampling point represents a distance of 2n meters from the reference point on the optical fiber. However, due to factors such as fiber bending, the actual distance from the nth sampling point to the reference point is less than 2n meters. In other words, the actual distance from the nth observation point to the reference point is less than 2n meters. This results in a non-one-to-one correspondence between observation points and sampling points. This invention aims to solve the problem of the non-one-to-one correspondence between observation points and sampling points.

[0129] The intelligent positioning device M7 is a standalone device used independently throughout the entire array. One intelligent positioning device can be used throughout the array, or multiple devices can be used simultaneously, as long as the positions of all observation points are calibrated before the actual data collection.

[0130] Example 5

[0131] The following example uses an optical fiber and a smart positioning device ( Figure 5 It involves setting up multiple smart positioning devices on a single optical fiber, with each smart positioning device performing... Figure 6 The following is an example of the positioning method, which involves manually inputting the location information of the observation point and starting to generate a vibration signal at a set time.

[0132] Location tracking is performed after the system has been deployed and is capable of collecting data normally.

[0133] First, the intelligent positioning device is deployed at the first observation point of the m-th survey line. The vibration module M77 of the intelligent positioning device M7 is fixed on the optical fiber. Then, the device is powered on and the positioning program is run.

[0134] like Figure 6 As shown, the positioning procedure includes:

[0135] (11) Power-on initialization.

[0136] (12) Receive input information from the input module. The input information includes: the coordinate position of the observation point where the intelligent positioning device M7 is located, the station number in the arrangement, the time when the vibration signal generation module M76 generates the corresponding signal and sends the vibration signal, and the frequency and amplitude of the generated vibration signal.

[0137] (13) Determine whether the information input is complete (the program has an input completion instruction set. Receiving this signal indicates that the input information is complete; otherwise, wait for the input information). If not, return to step (12). If yes, proceed to step (14).

[0138] (14) Determine if it is time to send a vibration signal (this can be done using a timer or GPS time). If not, return to step (14). If yes, proceed to step (15).

[0139] (15) Generating vibration signals: The main controller M71 sends a vibration signal command to the vibration signal generation module M76. After receiving the vibration signal command, the vibration signal generation module M76 generates an electrical signal. After receiving the electrical signal, the vibration module M77 starts to vibrate and generates a vibration signal.

[0140] (16) Determine whether the positioning of this observation point has ended (there are two ways to determine whether the positioning has ended: 1. The system controller M1 collects data, analyzes the collected data, finds information containing the corresponding observation point, and sends a positioning end command to the main controller M71; 2. Manual control via buttons). If not, return to step (14). If yes, return to step (12) to locate the next observation point.

[0141] By repeating the above process, the location of all observation points can be completed.

[0142] Example 6

[0143] like Figure 7 As shown in the figure, this diagram illustrates the workflow of the system controller M1 in the DAS during positioning. The positioning subroutine flow of the system controller M1 is as follows:

[0144] After the system completes all physical connections and is able to collect data normally, the positioning control subroutine is run, as follows:

[0145] (21) Perform positioning initialization.

[0146] (22) Data acquisition: In the DAS system, a set of optical pulses is sent. After the optical pulses are transmitted in the optical fiber, they are reflected back. The demodulator demodulates the signal containing vibration information on the optical fiber to form a data file, thus completing one data acquisition.

[0147] (23) Analyze whether the collected data contains location information (search for feature data from the collected data. When the collected data contains feature data indicating location, it is determined that there is location information. The specific analysis method is implemented using existing technology and will not be described in detail here.) If yes, proceed to step (24); otherwise, proceed to step (26).

[0148] (24) Extract the positioning information and use the positioning information to determine the sampling point corresponding to the observation point;

[0149] Because the amplitude of the sampling point directly connected to the intelligent positioning device is the largest, the fourth step includes:

[0150] Read the location information of the sampling point, which includes the geographic coordinates, station number and other information of the observation point; when the location information of multiple consecutive sampling points is the same, select the sampling point with the largest amplitude among these sampling points (i.e., multiple consecutive sampling points with the same location information) as the sampling point corresponding to the observation point.

[0151] The geographical coordinates of an observation point are its absolute location on the ground, while the station number is the survey line to which the observation point belongs in the exploration arrangement. During the same data collection in a work area, the geographical coordinates and station numbers are in one-to-one correspondence, meaning that each observation point has a unique station number.

[0152] The unprocessed collected data corresponds to vibration signals detected by a continuous fixed length of optical fiber. When a vibration signal is introduced at a point on the optical fiber via a smart positioning device, this vibration signal propagates in both directions along the fiber. The optical fibers on both sides of the observation point also receive the vibration signal information from that observation point, resulting in multiple sampling points containing the same positioning information (i.e., information from the same observation point). Therefore, it is necessary to select the sampling point with the largest amplitude as the sampling point corresponding to the observation point, thus determining the sequence number of the sampling point corresponding to the observation point.

[0153] (25) Establish a table of correspondence between sampling points and observation points: fill in the serial number of the observation point and the serial number of the corresponding sampling point into the table of correspondence between sampling points and observation points;

[0154] (26) Determine whether to end the positioning (pre-set the number of positioning points or manually enter the end positioning information). If not, return to step (22); if yes, proceed to step (27).

[0155] (27) Generate a table of corresponding sampling points and observation points (in the fifth step, fill in the positioning results obtained each time, and at this time, output all the positioning results) for use by the normal acquisition program (i.e. the acquisition program in the existing DAS system).

[0156] The table corresponding to sampling points and observation points includes the location (i.e., the sequence number of the observation point) of all intelligent positioning devices M7 and the corresponding sampling points, as shown in Table 1. For ease of explanation in this embodiment, it is used as an example where four consecutive observation points have intelligent positioning devices. In reality, the observation points with intelligent positioning devices installed do not necessarily have to be consecutive. The (m+n1)th sampling point corresponds to the mth observation point, the (m+n2)th sampling point corresponds to the (m+1)th observation point, the (m+n3)th sampling point corresponds to the (m+2)th observation point, and the (m+n4)th sampling point corresponds to the (m+3)th observation point, where n1... <n2<n3<n4。

[0157] Serial Number 1 2 3 4 Observation point m m+1 m+2 m+3 Sampling points m+n1 m+n2 m+n3 m+n4

[0158] Table 1

[0159] (28) Return to the previous program.

[0160] After running the program, the correspondence between all observation points and sampling points (the sampling point number is always equal to or greater than the observation point number) is obtained, i.e., the correspondence table between sampling points and observation points. The data can be reconstructed using this correspondence table.

[0161] Example 7

[0162] like Figure 8 As shown in the figure, the system data acquisition process is illustrated. The data acquisition subroutine of the system controller M1 in the DAS system operates as follows:

[0163] (31), data acquisition initialization;

[0164] (32) Collect data once;

[0165] (33) Read the table of correspondence between sampling points and observation points;

[0166] (34) Reconstruct the collected data file as follows:

[0167] The data of the sampling points corresponding to the observation points are retained, the data of the sampling points that do not correspond to the observation points are deleted, and the data files that correspond one-to-one with the observation points are regenerated and stored in the standard format of seismic exploration. Thus, one data acquisition is completed.

[0168] Due to the uneven terrain, the length of the buried optical cable is always greater than the actual distance between observation points. This results in the number of sampling points being much greater than the number of observation points during the initial DAS acquisition. After DAS completes one acquisition cycle, it is necessary to write the sampling point data corresponding to the observation point into the data location of the observation point according to the mapping table of acquired sampling points and observation points. Data without a corresponding observation point is directly deleted, forming the final acquisition data file containing only the sampling points corresponding to the observation points.

[0169] This invention achieves positioning by adding an intelligent positioning device M7 to an existing DAS system. The vibration signal is controllable, and it enables both local and remote control. Local control is achieved through human-computer interaction, inputting information such as the station number, coordinates, start and end correction times of the observation point. Remote control involves establishing communication between the system controller and the intelligent positioning device; the system controller inputs or sets relevant information, transmits it to the intelligent positioning device, and issues commands to control its operation. Furthermore, this invention achieves position correction (by installing an intelligent vibration device at the observation point to generate a vibration signal relevant to the observation point; by running the acquisition program, the correspondence between the observation point and the DAS sampling point is determined, thereby correcting the acquired data) and data file reconstruction.

[0170] During actual construction, before formally collecting data, the correspondence between all observation points and their corresponding sampling point numbers is tested to form a table of correspondence between observation points and sampling points. During the formal data collection process, the data of the corresponding number is extracted from the table of correspondence between observation points and sampling points as the data collected for the corresponding observation point, and a data collection file corresponding to each observation point is generated and stored.

[0171] The intelligent positioning device designed in this invention realizes the automatic detection of the coordinates of observation points through remote transmission and local input, and generates vibration signals containing the coordinates and station number information of the access observation points according to remote commands, local control, or pre-setting. In the system controller, by analyzing the received information, the location information and station number information of the observation points can be obtained. By using the correspondence table between observation points and sampling points, the sampling information of the observation points can be determined, and the data can be reconstructed based on this information, ensuring that the recorded data corresponds one-to-one with the actual observation points, thus solving the positioning problem of distributed fiber optic acoustic wave sensing systems (DAS).

[0172] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0173] In the description of this invention, unless otherwise stated, the terms "upper," "lower," "left," "right," "inner," "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0174] Finally, it should be noted that the above technical solution is only one embodiment of the present invention. For those skilled in the art, based on the application methods and principles disclosed in the present invention, it is easy to make various types of improvements or modifications, and not limited to the methods described in the above specific embodiments of the present invention. Therefore, the methods described above are only preferred and have no limiting significance.

Claims

1. A seismic acquisition method, characterized in that: The method is implemented using a seismic acquisition system. Before acquiring data, all observation points are located to obtain the correspondence between observation points and sampling points. During the data acquisition process, the sampling data is reconstructed using the correspondence between observation points and sampling points to obtain data files that correspond one-to-one with the observation points. The seismic acquisition system includes: a system controller, a light source modulator, an optical fiber signal demodulator, an optical fiber interface module, a vibration detection optical fiber, and a main communication module; An intelligent positioning device is provided on one or more of the vibration detection optical fibers; the intelligent positioning device includes: a main controller and a communication module, an input module, a positioning satellite receiving module, and a vibration signal generating module respectively connected to it; an antenna is connected to the positioning satellite receiving module; and a vibration module is connected to the vibration signal generating module. The operation of locating all observation points before collecting data includes: The vibration module of the intelligent positioning device is fixed to the vibration detection optical fiber, and then the intelligent positioning device runs the following program: (11) Power-on initialization; (12) Receive input information from the input module. The input information includes: the geographical coordinates of the observation point where the intelligent positioning device is located, the station number in the arrangement, the time when the vibration signal generation module generates the corresponding signal and sends the vibration signal, and the frequency and amplitude of the generated vibration signal. (13) Determine whether the information input is complete. If not, return to step (12). If yes, proceed to step (14). (14) Determine if it is time to send a vibration signal. If not, return to step (14). If yes, proceed to step (15). (15) Generating vibration signals: The main controller sends a vibration signal command to the vibration signal generation module. After receiving the vibration signal command, the vibration signal generation module generates an electrical signal. After receiving the electrical signal, the vibration module starts to vibrate and generates a vibration signal. (16) Determine whether the positioning of this observation point has ended. If not, return to step (14). If yes, return to step (12) to perform the positioning of the next observation point until the positioning of all observation points is completed.

2. The seismic acquisition method according to claim 1, characterized in that: An antenna is connected to the positioning satellite receiving module.

3. The seismic acquisition method according to claim 1, characterized in that: The vibration module includes: a fixed component and a vibration component; The fixing component includes two clamping blocks; Each clamping block is a cuboid structure with a through semi-cylindrical groove on one side. Threaded holes are provided on both sides of the cuboid structure. The central axis of the threaded holes is perpendicular to the central axis of the semi-cylindrical groove. A mounting groove is provided on one side of one of the clamping blocks, and the vibrating component is disposed in the mounting groove.

4. The seismic acquisition method according to claim 3, characterized in that: After the two clamping blocks are placed symmetrically, the threaded holes on both sides of the two clamping blocks are aligned. Bolts are inserted into the threaded holes on both sides and fixed with nuts. The semi-cylindrical grooves on the two clamping blocks form a cylindrical hole.

5. The seismic acquisition method according to claim 1, characterized in that: The light source modulator, fiber optic signal demodulator, and fiber optic interface module are respectively connected to the system controller. At the same time, the light source modulator and fiber optic signal demodulator are respectively connected to the fiber optic interface module, and multiple vibration detection fibers are respectively connected to the fiber optic interface module. The intelligent positioning device communicates with the system controller through a communication module and a main communication module.

6. The seismic acquisition method according to claim 1, characterized in that: The operation of obtaining the correspondence between observation points and sampling points includes: After the seismic acquisition system completes all physical connections and is able to acquire data normally, the system controller in the seismic acquisition system runs the following program: (21) Perform positioning initialization; (22) Collect data once; (23) Analyze whether the collected data contains location information. If yes, proceed to step (24); otherwise, proceed to step (26). (24) Use the location information to determine the sampling point corresponding to the observation point; (25) Establish a table of correspondence between sampling points and observation points: fill in the serial number of the observation point and the serial number of the corresponding sampling point into the table of correspondence between sampling points and observation points; (26) Determine whether the positioning has ended. If not, return to step (22). If yes, proceed to step (27). (27) Generate a table of correspondence between sampling points and observation points; (28) Return to the previous program.

7. The seismic acquisition method according to claim 6, characterized in that: The operation of step (24) includes: reading the positioning information of the sampling points; when the positioning information of multiple consecutive sampling points is the same, selecting the sampling point with the largest amplitude among these sampling points as the sampling point corresponding to the observation point.

8. The seismic acquisition method according to claim 1, characterized in that: The operation of reconstructing the sampled data using the correspondence between observation points and sampling points during the data acquisition process to obtain a data file that corresponds one-to-one with each observation point includes: The system controller in the seismic acquisition system runs the following program: (31), data acquisition initialization; (32) Collect data once; (33) Read the table of correspondence between sampling points and observation points; (34) Reconstruct the collected data file.

9. The seismic acquisition method according to claim 8, characterized in that: The operation of step (34) includes: retaining the data of the sampling points corresponding to the observation points, deleting the data of the sampling points that do not correspond to the observation points, regenerating the data files that correspond one-to-one with the observation points, and storing them in the standard format of seismic exploration.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores at least one computer-executable program, which, when executed by the computer, causes the computer to perform the steps in the seismic acquisition method as described in any one of claims 1-9.

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