Short-period time-lapse seismic acquisition method and device based on unmanned autonomous excitation on water surface

Abstract

The invention relates to the technical field of ocean geophysical exploration, in particular to a short-period time-lapse seismic acquisition method and device based on water surface unmanned autonomous excitation. The problems that in an existing time-lapse seismic data acquisition method, the time-lapse acquisition period is long, the large ship routing error is large, the ship labor cost is high, and the environmental adaptability is poor can be solved to a certain extent. The method comprises the steps that an unmanned ship carries a seismic source; arranging an ocean bottom seismograph at the seabed of an observation target sea area to collect seismic data and store the seismic data in situ, and connecting the ocean bottom seismograph with a water surface base station through an optical fiber cable to carry out data transmission; a star-shaped seismic survey line is designed on the water surface; performing autonomous cruise through the unmanned ship based on the seismic survey line; after measurement of all the seismic survey lines is completed, seismic data stored in situ by the ocean bottom seismograph are transmitted to a base station through an optical fiber; and the autonomous cruise of the unmanned ship is repeated to measure all the seismic lines, and short-period time-lapse seismic acquisition is realized.

Description

Technical Field

[0001] The present application relates to the technical field of marine geophysical exploration, and in particular to a short-period time-lapse seismic acquisition method and device based on unmanned autonomous excitation on the water surface. Background Art

[0002] Timelapse seismic technology monitors underground geological structures and fluid changes by repeatedly collecting seismic data in the same area at different times. It is widely used in oil and gas exploration, geothermal development, and geological disaster monitoring.

[0003] Traditional offshore time-lapse seismic data acquisition methods mainly rely on large survey ships for source excitation, and use towed cables or long-term seafloor seismometers for reception. The time-lapse observation period is usually several months to several years. Data repeatability is the key to the success of time-lapse seismic, including construction sea conditions, gun inspection point locations, seismic wavelet morphology, etc., which need to be highly consistent.

[0004] However, existing time-lapse seismic data acquisition methods have problems such as long time-lapse acquisition cycle, large alignment errors of large ships, high ship labor costs, and poor environmental adaptability. Summary of the invention

[0005] In order to solve the problems existing in the existing time-lapse seismic data acquisition methods, such as long time-lapse acquisition period, large error in large ship routing, high labor cost for ship use and poor environmental adaptability, the present application provides a short-period time-lapse seismic acquisition method and device based on unmanned autonomous excitation on the water surface.

[0006] The embodiment of the present application is implemented as follows:

[0007] In a first aspect, the present application provides a short-period time-lapse seismic acquisition method based on unmanned autonomous excitation on the water surface, comprising:

[0008] An unmanned boat-borne seismic source is formed by an unmanned boat, a main control computer, an autonomous navigation system, a seismic source system and a satellite communication system;

[0009] Seafloor seismometers are deployed on the seafloor of the target sea area to collect seismic data and store them in situ, and are connected to surface base stations via optical fiber cables for data transmission for real-time monitoring;

[0010] A M-shaped seismic survey line is designed on the water surface. The intersection of the six seismic survey lines is located directly above the seafloor seismometer. The length of each seismic survey line is 8 kilometers, and the distance between the guns is 20 meters.

[0011] Based on the seismic survey line, the unmanned boat performs autonomous cruising, and automatically excites the seismic source when reaching the gun point position and sends navigation status information to the base station through the satellite communication system;

[0012] After all the seismic survey lines are measured, the seismic data stored in situ by the seafloor seismometer is transmitted to the base station via optical fiber;

[0013] The autonomous cruising of the unmanned boat is repeated to measure all the seismic survey lines, thereby realizing short-period time-lapse seismic acquisition.

[0014] In a possible implementation, the main control computer is used for unmanned boat navigation control and source excitation control.

[0015] In a possible implementation, the autonomous navigation control system is configured with high-precision GPS, an inertial navigation system, and an automated control system to achieve precise navigation and positioning and autonomous navigation control.

[0016] In one possible implementation, the seismic source system includes a seismic source host and a transmitter, wherein the seismic source host can receive a trigger signal from a main control computer, and the transmitter is installed in the moon pool of the unmanned boat, and the water immersion depth is adjusted to ensure that the emitted seismic waves meet the exploration requirements.

[0017] In a possible implementation, the satellite communication system is used to transmit navigation status information to a base station.

[0018] In a possible implementation, the seafloor seismograph is a four-component seafloor seismograph; and the optical fiber cable is used for seismic data transmission.

[0019] In a possible implementation, the autonomous cruising of the unmanned boat is characterized in that the unmanned boat has a navigation speed of 4 knots on the seismic survey line and a navigation speed of 8 knots between lines; the navigation status information includes the excitation time, the gun point position, the gun point number, and the navigation speed.

[0020] In a second aspect, the present application provides a short-period time-lapse seismic acquisition device based on unmanned autonomous excitation on the water surface, comprising:

[0021] Unmanned vehicle module, used to form an unmanned boat-borne seismic source through an unmanned boat, a main control computer, an autonomous navigation system, a seismic source system and a satellite communication system;

[0022] The real-time monitoring module is used to deploy seafloor seismometers on the seafloor of the target sea area to collect seismic data and store them in situ, and connect them to the surface base station via optical fiber cables for data transmission for real-time monitoring;

[0023] The survey line design module is used to design a M-shaped seismic survey line on the water surface. The intersection of the six seismic survey lines is located directly above the seafloor seismometer. The length of each seismic survey line is 8 kilometers, and the distance between shots is 20 meters.

[0024] An autonomous cruising module, used to autonomously cruise based on the seismic survey line through the unmanned boat, and automatically stimulate the seismic source when reaching the gun point position and send navigation status information to the base station through the satellite communication system;

[0025] A data transmission module, used for transmitting the seismic data stored in situ by the seafloor seismometer to the base station via optical fiber after all the seismic survey lines have been measured;

[0026] The repeated acquisition module is used to repeatedly perform autonomous cruising of the unmanned boat to measure all the seismic survey lines, thereby realizing short-period time-lapse seismic acquisition.

[0027] The technical solution provided by this application can at least achieve the following beneficial effects:

[0028] The short-period time-lapse seismic acquisition method and device based on unmanned autonomous excitation on the water surface provided by the present application improves the stability and consistency of seismic source excitation; reduces the labor cost of ship use and improves work efficiency; and improves the adaptability and stability of the system in complex and harsh environments. In summary, the present invention solves many problems in the prior art through a time-lapse seismic data acquisition method based on unmanned autonomous excitation on the water surface, and has broad application prospects and important practical value. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, a brief introduction will be given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0030] Figure 1 It is a flow chart of a short-period time-lapse seismic acquisition method based on unmanned autonomous excitation on the water surface, shown in an exemplary embodiment of the present application;

[0031] Figure 2 is a schematic diagram of a M-shaped seismic survey line shown in an exemplary embodiment of the present application;

[0032] Figure 3 It is a structural schematic diagram of a short-period time-lapse seismic acquisition device based on unmanned autonomous excitation on the water surface, shown in an exemplary embodiment of the present application.

[0033] Reference numerals:

[0034] 1. Seismic survey line L1; 2. Seismic survey line L2; 3. Seismic survey line L3; 4. Seismic survey line L4; 5. Seafloor seismograph; 6. Unmanned vehicle module; 7. Real-time monitoring module; 8. Survey line design module; 9. Autonomous cruise module; 10. Data transmission module; 11. Repeated acquisition module. DETAILED DESCRIPTION

[0035] In order to make the purpose, implementation mode and advantages of the present application clearer, the exemplary implementation mode of the present application will be clearly and completely described below in conjunction with the drawings in the exemplary embodiments of the present application. Obviously, the described exemplary embodiments are only part of the embodiments of the present application, not all of the embodiments. It should be understood that the specific embodiments described here are only used to explain the present application and are not used to limit the present application.

[0036] It should be noted that the brief description of terms in this application is only for the convenience of understanding the embodiments described below, and is not intended to limit the embodiments of this application. Unless otherwise specified, these terms should be understood according to their common and usual meanings.

[0037] The terms "first", "second", "third", etc. in the specification and claims of this application and the above drawings are used to distinguish similar or similar objects or entities, and do not necessarily mean to limit a specific order or sequence, unless otherwise noted. It should be understood that the terms used in this way can be interchangeable under appropriate circumstances.

[0038] The terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover but not exclude inclusion, for example, a product or device comprising a list of components is not necessarily limited to all the components expressly listed but may include other components not expressly listed or inherent to such product or device.

[0039] Before explaining the short-period time-lapse seismic acquisition method based on unmanned autonomous excitation on the water surface provided in the embodiment of the present application, the application scenario and implementation environment of the embodiment of the present application are first introduced.

[0040] Timelapse seismic technology monitors underground geological structures and fluid changes by repeatedly collecting seismic data in the same area at different times. It is widely used in oil and gas exploration, geothermal development, and geological disaster monitoring.

[0041] Traditional offshore time-lapse seismic data acquisition methods mainly rely on large survey ships for source excitation, and use towed cables or long-term seafloor seismometers for reception. The time-lapse observation period is usually several months to several years. Data repeatability is the key to the success of time-lapse seismic, including construction sea conditions, gun inspection point locations, seismic wavelet morphology, etc., which need to be highly consistent.

[0042] However, the existing time-lapse seismic data acquisition methods have the following problems in practical applications:

[0043] 1. The collection cycle is long, usually repeated for several months to several years, which is not conducive to observations in areas with active offshore geological activities.

[0044] 2. Difficulty in excitation control: Large ships have large routing errors, making it difficult to ensure the consistency of each excitation position.

[0045] 3. High labor cost for ship operation: A large amount of manpower is required for equipment layout, excitation control and data collection, which is costly and inefficient.

[0046] 4. Poor environmental adaptability: In complex and harsh environments, manual operation is difficult, affecting the continuity and stability of data collection.

[0047] Based on this, the present application provides a short-period time-lapse seismic acquisition method and device based on unmanned autonomous excitation on the water surface, which improves the positioning accuracy of the active source excitation position and the stability and consistency of the seismic waveform; reduces the labor cost of ship use and improves work efficiency; and improves the adaptability and stability of the system in complex and harsh environments.

[0048] Next, the technical solution of the present application and how the technical solution of the present application solves the above-mentioned technical problems will be described in detail through embodiments and in combination with the accompanying drawings. The embodiments may be combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments. Obviously, the described embodiments are part of the embodiments of the present application, not all of them.

[0049] Figure 1 is a flow chart of a short-period time-lapse seismic acquisition method based on unmanned autonomous excitation on the water surface, shown in an exemplary embodiment of the present application. Figure 2 It is a schematic diagram of a M-shaped seismic survey line shown in an exemplary embodiment of the present application.

[0050] In an exemplary embodiment, Figure 1 and Figure 2 As shown, a short-period time-lapse seismic acquisition method based on unmanned autonomous excitation on the water surface is provided. In this embodiment, the method may include the following steps:

[0051] Step 100: An unmanned boat-borne seismic source is formed by using an unmanned boat, a main control computer, an autonomous navigation system, a seismic source system and a satellite communication system.

[0052] Step 200: Deploy seafloor seismometers on the seafloor of the target sea area to collect seismic data and store them in situ, and connect them to the surface base station via optical fiber cables for data transmission for real-time monitoring.

[0053] Step 300: Design a M-shaped seismic line on the water surface. The intersection of the six seismic lines is located directly above the seafloor seismometer. The length of each seismic line is 8 kilometers, and the distance between guns is 20 meters.

[0054] Step 400: Based on the seismic survey line, the unmanned boat performs autonomous cruising, and automatically excites the seismic source when reaching the gun point position and sends navigation status information to the base station via the satellite communication system.

[0055] Step 500: After all the seismic survey lines are measured, the seismic data stored in situ by the seafloor seismometer is transmitted to the base station via optical fiber.

[0056] Step 600: Repeat the autonomous cruising of the unmanned boat to measure all the seismic survey lines to achieve short-period time-lapse seismic acquisition.

[0057] In a possible implementation, the specific implementation method of the short-period time-lapse seismic data acquisition method is as follows:

[0058] Step 1) The unmanned boat-borne seismic source includes an unmanned boat, a main control computer, an autonomous navigation system, a seismic source system, and a satellite communication system;

[0059] Among them, the main control computer is used for unmanned boat navigation control and source excitation control; the autonomous navigation control system is equipped with high-precision GPS, inertial navigation system and automatic control system to achieve precise navigation and positioning and autonomous navigation control; the source system includes a source host and a transmitter, wherein the source host can receive the trigger signal of the main control computer, the transmitter is installed in the moon pool of the unmanned boat, and the water immersion depth is adjusted to ensure that the emitted seismic waves meet the exploration needs; the satellite communication system is used to transmit navigation status information to the base station.

[0060] Step 2) deploying a seafloor seismograph on the seabed of the target sea area to collect seismic data and store it in situ, and connecting it to a surface base station via an optical fiber cable, wherein the seafloor seismograph is a four-component seafloor seismograph; and the optical fiber cable is used for seismic data transmission.

[0061] Step 3) Design a M-shaped seismic line on the water surface. The intersection of the four seismic lines is located directly above the seafloor seismometer. The length of each seismic line is 8 kilometers, and the distance between the guns is 20 meters. (Optional)

[0062] Step 4) setting the unmanned boat in step 1) to cruise autonomously according to the seismic survey line designed in step 3), automatically exciting the seismic source when reaching the gun point position, and sending navigation status information to the base station through the satellite communication system;

[0063] Among them, the autonomous cruising of the unmanned boat is characterized in that the unmanned boat has a navigation speed of 4 knots on the seismic survey line and a navigation speed of 8 knots between lines; the navigation status information includes the excitation time, the gun point position, the gun point number, and the navigation speed.

[0064] Step 5) After all the seismic survey lines in step 3) are measured, the seismic data stored in situ by the seafloor seismometer is transmitted to the base station via optical fiber.

[0065] Step 6) When repeating the measurement, repeat steps 4) to 5) to achieve short-period time-lapse seismic acquisition.

[0066] It should be understood that, although the various steps in the flowcharts involved in the above-mentioned embodiments are displayed in sequence according to the instructions, these steps are not necessarily executed in sequence according to the order of the instructions. Unless there is a clear explanation in this article, the execution of these steps is not strictly limited in order, and these steps can be executed in other orders. Moreover, at least a portion of the steps in the flowcharts involved in the above-mentioned embodiments may include multiple steps or multiple stages, and these steps or stages are not necessarily executed at the same time, but can be executed at different times, and the execution order of these steps or stages is not necessarily to be carried out in sequence, but can be executed in turn or alternately with other steps or at least a portion of the steps or stages in other steps.

[0067] Corresponding to the aforementioned embodiment of the short-period time-lapse seismic acquisition method based on unmanned autonomous excitation on the water surface, adopting the same technical concept, the present application also provides an embodiment of a short-period time-lapse seismic acquisition device based on unmanned autonomous excitation on the water surface.

[0068] Figure 3 It is a structural schematic diagram of a short-period time-lapse seismic acquisition device based on unmanned autonomous excitation on the water surface, shown in an exemplary embodiment of the present application.

[0069] In an exemplary embodiment, Figure 3 As shown, the short-period time-lapse seismic acquisition device based on unmanned autonomous excitation on the water surface includes:

[0070] Unmanned vehicle module 6, used to form an unmanned boat-borne seismic source through an unmanned boat, a main control computer, an autonomous navigation system, a seismic source system and a satellite communication system;

[0071] Real-time monitoring module 7, used to deploy seafloor seismometers on the seafloor of the target sea area to collect seismic data and store them in situ, and connect to the surface base station via optical fiber cables for data transmission for real-time monitoring;

[0072] Survey line design module 8 is used to design a M-shaped seismic survey line on the water surface. The intersection of the six seismic survey lines is located directly above the seafloor seismometer. The length of each seismic survey line is 8 kilometers, and the distance between shots is 20 meters.

[0073] An autonomous cruising module 9 is used to perform autonomous cruising based on the seismic survey line through the unmanned boat, and automatically excite the seismic source when reaching the gun point position and send navigation status information to the base station through the satellite communication system;

[0074] The data transmission module 10 is used to transmit the seismic data stored in situ by the seafloor seismometer to the base station via optical fiber after all the seismic survey lines are measured;

[0075] The repeated acquisition module 11 is used to repeatedly perform autonomous cruising of the unmanned boat to measure all the seismic survey lines, thereby realizing short-period time-lapse seismic acquisition.

[0076] For the specific definition of the short-period time-lapse seismic acquisition device based on unmanned autonomous excitation on the water surface, please refer to the definition of the short-period time-lapse seismic acquisition method based on unmanned autonomous excitation on the water surface mentioned above, which will not be repeated here. Each module in the above-mentioned short-period time-lapse seismic acquisition device based on unmanned autonomous excitation on the water surface can be fully or partially implemented by software, hardware and a combination thereof. The above-mentioned modules can be embedded in or independent of the processor in the computer device in the form of hardware, or can be stored in the memory of the computer device in the form of software, so that the processor can call and execute the operations corresponding to the above modules.

[0077] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0078] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application shall be subject to the attached claims.

Claims

1. A short-period time-lapse seismic acquisition method based on unmanned autonomous excitation on the water surface, characterized in that: include: An unmanned boat-borne seismic source is formed by an unmanned boat, a main control computer, an autonomous navigation system, a seismic source system and a satellite communication system; Seafloor seismometers are deployed on the seafloor of the target sea area to collect seismic data and store them in situ, and are connected to surface base stations via optical fiber cables for data transmission for real-time monitoring; A M-shaped seismic survey line is designed on the water surface. The intersection of the six seismic survey lines is located directly above the seafloor seismometer. The length of each seismic survey line is 8 kilometers, and the distance between the guns is 20 meters. Based on the seismic survey line, the unmanned boat performs autonomous cruising, and automatically excites the seismic source when reaching the gun point position and sends navigation status information to the base station through the satellite communication system; After all the seismic survey lines are measured, the seismic data stored in situ by the seafloor seismometer is transmitted to the base station via optical fiber; The autonomous cruising of the unmanned boat is repeated to measure all the seismic survey lines, thereby realizing short-period time-lapse seismic acquisition.

2. The short-period time-lapse seismic acquisition method based on unmanned autonomous excitation on the water surface as claimed in claim 1, characterized in that: The main control computer is used for unmanned boat navigation control and source excitation control.

3. The short-period time-lapse seismic acquisition method based on unmanned autonomous excitation on the water surface as claimed in claim 1, characterized in that: The autonomous navigation control system is equipped with high-precision GPS, inertial navigation system and automatic control system to achieve precise navigation and positioning and autonomous navigation control.

4. The short-period time-lapse seismic acquisition method based on unmanned autonomous excitation on the water surface as claimed in claim 1, characterized in that: The seismic source system includes a seismic source host and a transmitter, wherein the seismic source host can receive a trigger signal from a main control computer, and the transmitter is installed in the moon pool of the unmanned boat and adjusts the water immersion depth to ensure that the emitted seismic waves meet the exploration requirements.

5. The short-period time-lapse seismic acquisition method based on unmanned autonomous excitation on the water surface as claimed in claim 1, characterized in that: The satellite communication system is used to transmit navigation status information to the base station.

6. The short-period time-lapse seismic acquisition method based on unmanned autonomous excitation on the water surface as claimed in claim 1, characterized in that: The seafloor seismograph is a four-component seafloor seismograph; The optical fiber cable is used for seismic data transmission.

7. The short-period time-lapse seismic acquisition method based on unmanned autonomous excitation on the water surface as claimed in claim 1, characterized in that: The autonomous cruising of the unmanned boat is characterized in that the navigation speed of the unmanned boat on the seismic survey line is 4 knots and the navigation speed between lines is 8 knots; the navigation status information includes the excitation time, the gun point position, the gun point number, and the navigation speed.

8. A short-period time-lapse seismic acquisition device based on unmanned autonomous excitation on the water surface, characterized in that: include: Unmanned vehicle module, used to form an unmanned boat-borne seismic source through an unmanned boat, a main control computer, an autonomous navigation system, a seismic source system and a satellite communication system; The real-time monitoring module is used to deploy seafloor seismometers on the seafloor of the target sea area to collect seismic data and store them in situ, and connect them to the surface base station via optical fiber cables for data transmission for real-time monitoring; The survey line design module is used to design a M-shaped seismic survey line on the water surface. The intersection of the six seismic survey lines is located directly above the seafloor seismometer. The length of each seismic survey line is 8 kilometers, and the distance between shots is 20 meters. An autonomous cruising module, used to autonomously cruise based on the seismic survey line through the unmanned boat, and automatically stimulate the seismic source when reaching the gun point position and send navigation status information to the base station through the satellite communication system; A data transmission module, used for transmitting the seismic data stored in situ by the seafloor seismometer to the base station via optical fiber after all the seismic survey lines have been measured; The repeated acquisition module is used to repeatedly perform autonomous cruising of the unmanned boat to measure all the seismic survey lines, thereby realizing short-period time-lapse seismic acquisition.

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