Method for magnetotelluric inversion of geological structure model of qiangtang basin

Abstract

The application discloses a method for inverting a geological structure model of the Qiangtang basin by using magnetotelluric data, and relates to the technical field of model construction. A plurality of magnetotelluric observation points are arranged within a management range, a plurality of magnetotelluric observation points are collected to obtain a collection network, and an association between the collection network and a management platform is established. Raw data collected by the collection network are provided to the management platform based on the association for storage. The raw data are processed to obtain observation data, forward calculation is performed on the basis of an initial geological model of the Qiangtang basin to obtain a forward calculation result, the forward calculation result is compared with the observation data, and if the difference exceeds a preset value, the initial geological model of the Qiangtang basin is updated through inversion calculation to obtain a geological structure model. The application can quickly understand the transmission stability and safety of data, provide stable and accurate observation data for updating and adjusting of the model in the management platform, and make the adjustment of the model conform to real geological electromagnetic data.

Description

Technical Field

[0001] This invention relates to the field of model building technology, specifically to a method for magnetotelluric inversion of the geological structure model of the Qiangtang Basin. Background Technology

[0002] The Qiangtang Basin, located in the Tethyan tectonic domain, one of the world's richest in oil and gas resources, is a large marine oil and gas basin that has not yet undergone large-scale oil and gas exploration, possessing the basic geological conditions for the formation of large oil and gas fields. Studying the geological structural model of the Qiangtang Basin using techniques such as magnetotelluric inversion is helpful in understanding the distribution and potential of oil and gas resources within the basin. However, the construction of geological structural models is typically a lengthy process, requiring timely collection of raw data. Due to the large volume of data and the long timeframe, the data collection process is susceptible to interference from various factors, leading to inaccurate data. This results in two problems: firstly, it extends the collection period, requiring re-collection; secondly, it can introduce erroneous data that affects the accurate construction of the geological structural model. Summary of the Invention

[0003] The purpose of this invention is to provide a method for magnetotelluric inversion of the geological structure model of the Qiangtang Basin, so as to solve the problems in the background technology.

[0004] To achieve the above objectives, the present invention provides the following technical solution: a method for magnetotelluric inversion of the geological structure model of the Qiangtang Basin, comprising the following steps:

[0005] Determine the management scope of the target Qiangtang Basin, collect existing data within the management scope, construct an initial geological model of the Qiangtang Basin based on the existing data, and store it in the management platform;

[0006] Multiple magnetotelluric observation points are set up within the management area, and the multiple magnetotelluric observation points are aggregated to form a data acquisition network. The relationship between the data acquisition network and the management platform is then established.

[0007] Based on the correlation, the raw data collected by the data collection network is provided to the management platform for storage;

[0008] The raw data is processed to obtain observation data. Forward modeling is performed based on the initial geological model of the Qiangtang Basin to obtain forward modeling results. The forward modeling results are compared with the observation data. If the difference exceeds the preset value, the initial geological model of the Qiangtang Basin is updated through inversion calculation to obtain a geological structure model.

[0009] In a preferred embodiment, the steps of determining the management scope of the target Qiangtang Basin, collecting existing data within the management scope, constructing an initial geological model of the Qiangtang Basin based on the existing data, and storing it in the management platform include:

[0010] The management scope of the target Qiangtang Basin shall be delineated, including both horizontal management scope and stratigraphic depth scope.

[0011] Existing data within the management area of ​​the Qiangtang Basin are collected, and underground geological bodies within the management area are constructed based on the existing data to obtain an initial geological model of the Qiangtang Basin, which is then stored in the management platform.

[0012] In a preferred embodiment, the steps of arranging multiple magnetotelluric observation points within the management area, aggregating the multiple magnetotelluric observation points to form a data acquisition network, and establishing the association between the data acquisition network and the management platform include:

[0013] Multiple magnetotelluric observation points were identified within the management area, and their locations were marked on the initial geological model of the Qiangtang Basin.

[0014] A data acquisition network is configured for multiple magnetotelluric observation points. The data acquisition network includes multiple data acquisition points, the number of which is the same as the number of magnetotelluric observation points and they correspond one-to-one. The receiving network is set up in the management platform for the corresponding data acquisition network.

[0015] Establish the connection between the data acquisition network and the receiving network in the management platform.

[0016] In a preferred embodiment, the step of setting up the receiving network in the management platform for the corresponding acquisition network includes:

[0017] A host computer is configured to correspond to multiple magnetotelluric observation points. The number of acquisition points is set in the storage space of the host computer as the number of magnetotelluric observation points. The acquisition points are bound to the magnetotelluric observation points, and the multiple acquisition points are used as an acquisition network.

[0018] Multiple encapsulation packets are set for each collection point. Each encapsulation packet consists of a data packet and multiple data units, which are connected to each other.

[0019] In the management platform, receiver points are configured for the multiple magnetotelluric observation points marked on the initial geological model of the Qiangtang Basin, and these multiple receiver points are used as a receiving network.

[0020] In a preferred embodiment, the step of establishing the association between the acquisition network and the receiving network in the management platform includes:

[0021] Connect the acquisition points and receiving points corresponding to the magnetotelluric observation points, and set an additional channel between the corresponding acquisition points and the corresponding receiving points;

[0022] Multiple mirroring windows are set between the channel and the supplementary channel. Each mirroring window includes the channel port in the channel, the corresponding image area of ​​the channel port, the supplementary port in the supplementary channel, and the corresponding image area of ​​the supplementary port. Multiple image points are set in the image area.

[0023] In a preferred embodiment, the step of providing the raw data collected by the acquisition network to the management platform for storage based on the association relationship includes:

[0024] The magnetotelluric acquisition equipment set up based on the magnetotelluric observation point collects raw data and timestamps the raw data.

[0025] The magnetotelluric data acquisition equipment transmits the collected raw data to the corresponding acquisition point in the host computer. It encapsulates the raw data for a preset time period into encapsulated data, and then transmits the encapsulated data through the channel and the additional channel until it is transmitted to the corresponding receiving point of the management platform for storage.

[0026] In a preferred embodiment, the step of transmitting the original encapsulated data through the channel and the additional channel until it is transmitted to the receiving point corresponding to the management platform for storage includes:

[0027] At the collection points, the raw data for the preset time period are determined sequentially according to the collection time. After each preset time period of raw data is collected, a new encapsulation packet is immediately activated.

[0028] The raw data for the preset time period is stored in the corresponding data packet with the enabled encapsulation packet. Multiple data units are bound to the raw data. Then, the storage address of the data unit in the data packet is determined, and the daisy-chain relationship between the multiple data units is determined. The daisy-chain relationship is a connection architecture composed of the storage addresses of the multiple data units in the data packet and their mutual connection relationship.

[0029] Based on the hand-holding relationship, multiple data units are copied to obtain the hand-holding group;

[0030] The original data for the preset time period is backed up on the host computer. The hand-in-hand group and the package containing the original data for the preset time period are transmitted simultaneously. The hand-in-hand group is transmitted through an additional channel, and the package containing the original data for the preset time period is transmitted through the channel. During the transmission, when the package passes through the channel port in the channel, the data unit in the package coincides and connects with the recording point in the recording area. After the recording point is activated, it is immediately disconnected to obtain the recording verification point.

[0031] When the data unit in the hand-in-hand group reaches the additional port through the additional channel, the data unit in the hand-in-hand group coincides and connects with the recording point in the recording area, and disconnects immediately after the recording point is activated to obtain the recording verification point;

[0032] The image verification point of the channel port in the mirror window is compared with the image verification point of the additional port. If they cannot be overlapped, it means that the data in the encapsulation packet has changed. The encapsulation packet and the corresponding daisy-chain are destroyed. The original data of the corresponding preset time period in the host computer is resent through the encapsulation packet until the original data of the preset time period is transmitted to the management platform. The original data of the corresponding preset time period in the host computer is then deleted.

[0033] In a preferred embodiment, the steps of processing the raw data to obtain observation data, performing forward modeling calculations based on the initial geological model of the Qiangtang Basin to obtain forward modeling results, comparing the forward modeling results with the observation data, and updating the initial geological model of the Qiangtang Basin through inversion calculations to obtain a geological structural model include:

[0034] The raw data is denoised, frequency-domain transformed, and derived parameters are calculated in the management platform to obtain the observation data.

[0035] The initial geological model of the Qiangtang Basin was forward modeled using the finite difference staggered grid method. The forward modeling results were then compared with the observation data. If the difference exceeded the preset value, the conjugate gradient method was used for iterative inversion to update the initial geological model of the Qiangtang Basin and obtain the geological structure model.

[0036] The technical effects and advantages provided by the present invention in the above technical solution are as follows:

[0037] This invention, by establishing a connection between the data acquisition network and the management platform, eliminates the need for stability analysis during data transmission. Instead, data stability is set directly during pre-transmission data packaging, and correlation comparisons are performed directly during transmission. This makes data transmission monitoring more direct and efficient. It allows for rapid understanding of data transmission stability and security issues, providing stable and accurate observational data for model updates and adjustments within the management platform, ensuring that model adjustments align with real-world geoelectromagnetic data. Attached Figure Description

[0038] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this invention. For those skilled in the art, other drawings can be obtained based on these drawings.

[0039] Figure 1 This is a flowchart of the method of the present invention.

[0040] Figure 2This is a system block diagram showing the relationship between the data acquisition network and the management platform of the present invention.

[0041] Figure 3 This is a logic block diagram showing the connection between the acquisition point and the receiving point in this invention. Detailed Implementation

[0042] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0043] Example 1, please refer to Figure 1 As shown in this embodiment, a method for magnetotelluric inversion of the geological structure model of the Qiangtang Basin includes the following steps:

[0044] S1. Determine the management scope of the target Qiangtang Basin, collect existing data within the management scope, construct an initial geological model of the Qiangtang Basin based on the existing data, and store it in the management platform;

[0045] S2. Set up multiple magnetotelluric observation points within the management area, combine the multiple magnetotelluric observation points to form a data acquisition network, and establish the relationship between the data acquisition network and the management platform;

[0046] S3. Based on the correlation, the raw data collected by the data collection network is provided to the management platform for storage;

[0047] S4. Process the raw data to obtain observation data. Perform forward modeling calculations based on the initial geological model of the Qiangtang Basin to obtain forward modeling results. Compare the forward modeling results with the observation data. If the difference exceeds the preset value, update the initial geological model of the Qiangtang Basin through inversion calculations to obtain a geological structure model.

[0048] As described in steps S1-S4 above, due to the large data volume and long collection period, the data is prone to interference from various factors during the data collection process. Therefore, it is necessary to conduct security monitoring of the raw data collection process. Factors that interfere with the raw data include electromagnetic influences from the collection site, network stability interference, and attacks from other networks. By establishing a connection between the collection network and the management platform, it is not necessary to analyze the stability of the data during transmission. The stability can be directly set during the pre-transmission packaging process, and the relationship can be directly compared during transmission. This makes data transmission monitoring more direct and efficient. It can quickly identify data transmission stability and security issues, providing stable and accurate observation data for updating and adjusting the model in the management platform, ensuring that the model adjustment conforms to the actual geological electromagnetic data.

[0049] In one embodiment, step S1, which involves determining the management scope of the target Qiangtang Basin, collecting existing data within the management scope, constructing an initial geological model of the Qiangtang Basin based on the existing data, and storing it in the management platform, includes:

[0050] S11. Delineate the management scope of the target Qiangtang Basin, which includes the horizontal management scope and the stratigraphic depth scope;

[0051] S12. Collect existing data within the management area of ​​the Qiangtang Basin (construct an initial geological model of the Permian-Neogene sedimentary cover in the basin by collecting existing geological, gravity and magnetic, seismic, and deep well data), construct the underground geological bodies within the management area based on the existing data, obtain the initial geological model of the Qiangtang Basin, and store it in the management platform.

[0052] As described in steps S11 and S12 above, the Qiangtang Basin is located in the northern part of the Qinghai-Tibet Plateau and is an important part of the eastern segment of the Tethys tectonic domain. Its geological structure is characterized by a well-developed fault system and complex geological structure. Magnetotelluric exploration is characterized by its sensitivity to differences in the electrical properties of underground media, its large detection depth (from shallow sedimentary cap to deep basement), and its minimal influence from topography. Specifically, the horizontal management scope and stratigraphic depth range of the target Qiangtang Basin are first delineated. An initial geological model of the Qiangtang Basin is then constructed based on the existing geological structure of the relevant management scope, serving as the starting point for inversion. The initial geological model of the Qiangtang Basin is an initial resistivity model or geological structure model. Based on existing geological maps and drilling data, the approximate distribution of strata and the initial resistivity value can be determined. Inversion can be performed based on existing data, making model determination faster. Furthermore, the inversion process is constrained by data, which can improve the efficiency of model determination. Subsequently, the three-dimensional resistivity structure of the subsurface was obtained through inversion, the boundary between the sedimentary cap and the basement was delineated, and reservoirs such as fault zones and karst caves were identified. Combined with seismic and gravity and magnetic data, an integrated geological-geophysical model was constructed to provide a basis for the selection of oil and gas exploration targets and the prediction of mineral resources.

[0053] Please see Figure 2 and Figure 3 As shown, in one embodiment, step S2, which involves arranging multiple magnetotelluric observation points within the management area, aggregating the multiple magnetotelluric observation points to form a data acquisition network, and establishing the association between the data acquisition network and the management platform, includes:

[0054] S21. Within the management area, identify multiple magnetotelluric observation points and mark their locations on the initial geological model of the Qiangtang Basin.

[0055] S22. Configure a data acquisition network for multiple magnetotelluric observation points. The data acquisition network includes multiple data acquisition points. The number of data acquisition points is the same as the number of magnetotelluric observation points and they correspond one-to-one. Set up a receiving network for the corresponding data acquisition network in the management platform.

[0056] S23. Establish the association between the data acquisition network and the receiving network in the management platform.

[0057] In one embodiment, step S22, which involves setting up the receiving network in the management platform for the corresponding acquisition network, includes:

[0058] S221. A host computer is configured to correspond to multiple magnetotelluric observation points. The number of acquisition points is the same as the number of magnetotelluric observation points in the storage space of the host computer. The acquisition points are bound to the magnetotelluric observation points, and the multiple acquisition points are used as an acquisition network.

[0059] S222. For each collection point, multiple encapsulation packets are set up. Each encapsulation packet consists of a data packet and multiple data units, and the data units are connected to each other.

[0060] S223. In the management platform, configure receiving points for the multiple magnetotelluric observation points marked on the initial geological model of the Qiangtang Basin, and use the multiple receiving points as a receiving network.

[0061] In one embodiment, step S23, which establishes the association between the acquisition network and the receiving network in the management platform, includes:

[0062] S231. Connect the acquisition points and receiving points corresponding to the magnetotelluric observation points, and set an additional channel between the corresponding acquisition points and the corresponding receiving points.

[0063] S232. Set up multiple mirror windows between the channel and the additional channel. The mirror window includes the channel port in the channel, the mirror area of ​​the corresponding channel port, the additional port in the additional channel, and the mirror area of ​​the corresponding additional port. Multiple mirror points (mirror points are virtual machines) are set in the mirror area.

[0064] As described in steps S21-S23 above, firstly, multiple magnetotelluric observation points are selected within the defined management area. These observation points are the chosen locations for data acquisition. The selection of observation points requires first clarifying the core exploration targets and delineating key areas. Then, based on existing data, preliminary screening of candidate observation areas is conducted (i.e., based on the initial geological model of the Qiangtang Basin). Next, the point spacing and layout pattern are determined, balancing resolution and efficiency. Finally, field reconnaissance is conducted to verify and determine the final magnetotelluric observation point location. Magnetotelluric acquisition equipment, such as the F3 magnetotellurist or the UltraEMZ4 magnetotelluric system, is then installed at these points, both possessing multi-sampling rate real-time acquisition capabilities. For example, the F3 magnetotellurist can achieve continuous acquisition and real-time calculation, displaying single-point time series, power spectrum, apparent resistivity, and other data in real time. In the actual data collection work in the Qiangtang Basin, to ensure data quality, the observation time for each broadband magnetotelluric (MT) point is no less than 30 hours, and the observation time for each long-period MT point is no less than 7 days. The specific time can be set according to the work progress. To better manage the subsequent data of each point, the locations of multiple MT points are marked on the initial geological model of the Qiangtang Basin. The MT points are distributed on the surface, and the points are marked on the surface of the initial geological model of the Qiangtang Basin. Since it is necessary to collect the data collected by the MT acquisition equipment at the MT points, the locations of the points need to be marked on the initial geological model of the Qiangtang Basin. In actual work, since there are multiple MT points and the core area of ​​the Qiangtang Basin is mostly uninhabited with little natural interference, a single-point rotation acquisition mode is usually adopted. That is, one set of equipment collects data sequentially at different observation points, or multiple sets of equipment collect data in parallel in different areas without strict synchronization. To ensure the efficiency of data acquisition, multiple sets of equipment are used to collect data in different areas. Therefore, not all MT points are equipped with MT acquisition equipment at the same time.

[0065] When multiple magnetotelluric (MT) acquisition devices are collecting data at different magnetotelluric observation points, GPS synchronization clocks can be used to ensure that all devices at all observation points collect data simultaneously within the same time period. Since there are multiple observation points, an integrated host computer is configured for each point to collect the data in real time. The host computer is configured with corresponding acquisition points based on the number of observation points, with a one-to-one correspondence. These acquisition points serve as data storage spaces for the respective observation points, storing the data collected by the acquisition devices. Multiple encapsulation packets are then set up for each acquisition point. Each packet consists of a data packet and multiple individual data units, which are interconnected. These individual data units are used for subsequent monitoring of the data packets to prevent changes in the data collected by the acquisition devices during transmission. Monitoring the security status of data transmission prevents erroneous data from being transmitted to the management platform, which could lead to incorrect analysis and an inability to obtain a correct model. Receiver points were configured at multiple magnetotelluric observation points marked on the initial geological model corresponding to the Qiangtang Basin. These receiver points formed a receiving network, connecting the corresponding acquisition points to the receiver points. An additional channel was set up between the acquisition and receiver points. Multiple mirror windows were established between the main channel and the additional channel. Each mirror window included a channel port, a corresponding image area for the channel port, an additional port, and a corresponding image area for the additional channel. Multiple image points (virtual machines) were set within each image area. The main channel and the additional channel were connected via channel ports and dedicated ports. Multiple nodes (of equal number) were set up in both the main channel and the additional channel, connected via channel ports and additional ports. Each node contained an image area with multiple image points closely distributed within it. This image area allowed for status monitoring of data acquired from subsequent magnetotelluric observation points during transmission, ensuring data security and preventing data corruption due to interference, thus avoiding erroneous data being provided to the management platform.

[0066] In one embodiment, step S3, which provides the raw data collected by the acquisition network to the management platform for storage based on the association relationship, includes:

[0067] S31. Collect raw data using magnetotelluric acquisition equipment set up based on magnetotelluric observation points, and mark the raw data with timestamps;

[0068] S32. The magnetotelluric data acquisition equipment transmits the acquired raw data to the corresponding acquisition point in the host computer (the host computer is close to the magnetotelluric observation point in terms of communication and can temporarily store the raw data acquired by the magnetotelluric observation point). The raw data for the preset time period is encapsulated into a package to obtain raw encapsulated data. The raw encapsulated data is transmitted through the channel and the additional channel until it is transmitted to the receiving point corresponding to the management platform for storage (the raw data is used to verify the forward modeling results and drive the inversion iteration in the subsequent forward modeling calculation).

[0069] In one embodiment, step S32, which involves transmitting the original encapsulated data through a channel and an additional channel until it reaches the receiving point corresponding to the management platform for storage, includes:

[0070] S321. In the collection points, determine the raw data of the preset time period in the order of collection time. After each preset time period of raw data is collected, immediately activate a package.

[0071] S322. Store the raw data of the preset time period in the data packet of the corresponding enabled encapsulation packet (the data packet is a virtual machine), bind multiple data units to the raw data, then determine the storage address of the data unit in the data packet, and determine the daisy-chain relationship between the multiple data units. The daisy-chain relationship is the connection architecture composed of the storage addresses of the multiple data units in the data packet and their mutual connection relationship.

[0072] S323. Based on the hand-holding relationship, copy multiple data units to obtain the hand-holding group;

[0073] S324. Back up the original data for the preset time period in the host computer. Simultaneously transmit the hand-in-hand group and the package containing the original data for the preset time period. The hand-in-hand group is transmitted through an additional channel, and the package containing the original data for the preset time period is transmitted through the channel. During the transmission, when the package passes through the channel port in the channel, the data unit in the package coincides and connects with the recording point in the recording area. After the recording point is activated, it is immediately disconnected to obtain the recording verification point.

[0074] S325. When the data unit in the hand-in-hand group reaches the additional port through the additional channel, the data unit in the hand-in-hand group coincides and connects with the recording point in the recording area, and disconnects immediately after the recording point is activated to obtain the recording verification point.

[0075] S326. Compare the image verification points of the channel port and the additional port in the mirror window. If they cannot be overlapped, it means that the data in the encapsulation packet has changed. Then, adjust the encapsulation packet and its corresponding...

[0076] All data is destroyed. The original data for the corresponding preset time period in the host computer is retransmitted in a package until the original data for the preset time period is transmitted to the management platform, at which point the original data for the corresponding preset time period in the host computer is deleted.

[0077] As described in steps S31-S32 above, after constructing the initial geological model of the Qiangtang Basin and determining the magnetotelluric observation points, raw data can be collected using magnetotelluric acquisition equipment at these points. This raw data serves as the standard for forward modeling comparison. When collecting the raw data, a host computer can be set up to integrate multiple magnetotelluric acquisition devices currently in operation. The number and location of magnetotelluric acquisition devices at various observation points are determined based on actual needs, given the large number of observation points. This allows for remote access to the raw data. In addition to timely forward and inverse modeling calculations, and to avoid the insecurity of long-term data storage outside the management platform, data needs to be acquired promptly and stored in the management platform for comprehensive centralized security management. Data received by the host computer of nearby devices can be collected promptly. First, the raw data collected by the magnetotelluric acquisition equipment is timestamped and then transmitted to the host computer. The host computer has acquisition points corresponding to the magnetotelluric observation points. The raw data collected by the magnetotelluric acquisition equipment at the corresponding observation points is obtained through these acquisition points. The host computer collects data according to the preset acquisition sequence. After the raw data for a specific time period, for example, if the preset time period is within 5 seconds, then the raw data in the host computer is encapsulated and packaged every 5 seconds. The specific packaging method is as follows: the raw data within the preset time period is stored in a data packet (a virtual machine). Multiple data units within the data packet are then "pinned" to the raw data. Each data unit is also a virtual machine, and they are bound to the raw data. The specific operation of "pinning" involves setting up a data chain within the data packet. The data chain consists of multiple data storage points and corresponding sub-units, with the data storage points arranged in a chain. The data is distributed in a modular fashion, with adjacent sub-units interconnected. The data storage point is the storage location and range (storage address and storage capacity, where the storage capacity is limited to the data size of the sub-segment) in the data packet. The sub-unit is a virtual machine at the storage location. The raw data for a preset time period is divided into multiple sub-segments according to the number of sub-units, and the multiple sub-segments are stored sequentially in the sub-units of the data storage point. According to the data of the data unit, the multiple sub-units are assigned to the data unit for binding. For example, there are 8 sub-segments and 8 sub-units, and 4 data units.Eight sub-segments are stored one-to-one in sub-units sequentially according to the acquisition time. Then, in a chain-like distribution, two sub-units are bound to one data unit. The storage center of the storage range of the two sub-units is used as the storage address of the data unit in the data packet. In this way, each of the four data units is bound to two sub-units and its storage address in the data packet is determined, establishing a chain-like relationship. When the amount of data in a sub-unit changes, the data storage point becomes disconnected from adjacent data storage points, and the corresponding sub-unit at that data storage point is automatically destroyed. The next sub-unit in sequence then moves to... At the data storage point where the destroyed sub-unit is located, all subsequent sub-units in the same order will move forward. Since the data unit is always located in the center of the storage range of the bound sub-unit, and each data unit is bound to one or more corresponding sub-units in sequence, when the sub-unit moves, the storage address of the data unit in the data packet and the connection relationship between them will change. This will change the tandem relationship, and it will no longer be able to coincide with the tandem group. Therefore, the subsequent image verification point in the mirror window will not be able to correspond, which means that the data in the package has changed and there is an insecure situation.The location of a single data unit within a data packet is determined, represented by its storage address. The storage addresses of multiple data units are then determined, and these data units are interconnected. With the storage addresses fixed, the connection structure between the data units is also determined, forming a daisy-chain relationship. This daisy-chain relationship is composed of the storage addresses of the data units within their respective data packets and their interconnections. To monitor the encapsulated packets containing the original data, the data units corresponding to the daisy-chain relationship need to be copied. Only the connection structure between the data units is copied; the original data is not copied. The copied daisy-chain relationship is considered a "daisy-chain group." Before transmission, due to uncertainty about the stable and successful transmission of the original data, a temporary backup of the original data is performed on the host computer. This backup is only deleted from the host computer once the original data for the preset time period is safely transmitted to the management platform. During transmission, the daisy-chain group and the encapsulated packets containing the original data for the preset time period are transmitted simultaneously. The daisy-chain group is transmitted through an additional channel, while the encapsulated packets are transmitted through the main channel. During transmission, the encapsulation... When a packet passes through a channel port in the channel, the data unit in the encapsulated packet coincides with and connects to a recording point in the recording area. After activating the recording point, it immediately disconnects. When multiple data units coincide with different recording points simultaneously, the corresponding recording points are activated at the same time. Then, they will not connect to other recording points again. This connection is called a connection. After the data unit connects to the recording point, it activates the recording point and simultaneously disconnects the connection between the recording point and the data unit, thus obtaining a recording verification point. The number of recording points corresponding to the recording verification points is the same as the number of data units. For example, if there are multiple recording points in the recording area with a high density, as long as multiple data units pass through the recording area, there will be recording points corresponding to the relationships between the multiple data units, thus resulting in overlapping recording points.In the supplementary channel, the activation operation is the same for both the individual data units in the daisy-chain group and the image points in the image area of ​​the supplementary port. This ensures that there are image verification points within the same mirror window. The image verification points of the channel port and the supplementary port in the mirror window are compared for overlap. If they cannot overlap, it indicates a change in the data within the encapsulated packet. The encapsulated packet and the corresponding daisy-chain group are then destroyed. The original data for the corresponding preset time period in the host computer is retransmitted through the encapsulated packet until the original data for the preset time period is transmitted to the management platform. The original data for the corresponding preset time period in the host computer is then deleted. Based on this, after a single encapsulated packet passes the mirror window transmission verification in the channel, the activated image points in the mirror window are deactivated, eliminating the record of the daisy-chain relationship for that data unit. This prepares for subsequent data transmission, making stability verification during data transmission more direct and efficient. Through the association between the acquisition network and the management platform, stability analysis of the data during transmission can be avoided. This is achieved by setting the stability during the pre-transmission packaging process and directly comparing the image relationships during transmission, making data transmission monitoring more direct and efficient. This allows for rapid understanding of data transmission stability and security issues, providing stable and accurate observational data for model updates and adjustments within the management platform, ensuring that model adjustments align with real-world geomagnetic data.

[0078] In one embodiment, step S4, which involves processing the raw data to obtain observation data, performing forward modeling calculations based on the initial geological model of the Qiangtang Basin to obtain forward modeling results, comparing the forward modeling results with the observation data, and updating the initial geological model of the Qiangtang Basin through inversion calculations to obtain a geological structural model, includes:

[0079] S41. In the management platform, the raw data is denoised, frequency domain transformed, and derived parameters are calculated to obtain the observation data;

[0080] S42. Based on the finite difference staggered grid division method, the initial geological model of the Qiangtang Basin is forward modeled to obtain the forward modeling results. The forward modeling results are compared with the observation data. If the difference exceeds the preset value, the conjugate gradient method is used for iterative inversion to update the initial geological model of the Qiangtang Basin and obtain the geological structure model.

[0081] As described in steps S41 and S42 above, the original data is first denoised, specifically by removing interference (such as power frequency interference and lightning pulse interference in the Qiangtang Basin) from the original electric and magnetic field time-domain signals, while retaining the effective electromagnetic signals. Then, the denoised data is frequency-domain transformed, specifically by converting the original time-domain data (voltage and magnetic field strength that change with time) into frequency-domain data (amplitude and phase corresponding to different frequencies) through Fourier transform. Finally, the derived parameters are calculated, specifically by calculating the apparent resistivity and impedance phase based on the frequency-domain data. The apparent resistivity and impedance phase are observational data directly used in the inversion calculation, which can intuitively reflect the electrical differences of the underground medium. Inversion calculations use observed data as a standard (constraint) to continuously adjust the parameters of the initial geological model for the Qiangtang Basin until the theoretical response of the model matches the observed data derived from the original data. The specific process includes: building an initial resistivity model based on existing data (collecting existing geological, gravity, magnetic, seismic, and deep well data); obtaining the theoretical apparent resistivity and phase through forward modeling; then comparing the theoretical data obtained from forward modeling with the observed data, calculating the difference using error functions (such as residuals and root mean square errors); if the error exceeds a threshold, adjusting the model parameters according to the direction of the difference, for example, for the resistivity value of a certain area in the Qiangtang Basin, re-forward modeling and comparison, until the theoretical data and the observed data derived from the original data meet the accuracy requirements (until the error function converges to meet certain accuracy requirements, such as reaching a predetermined number of iterations or the data residual is less than a preset threshold); throughout the entire inversion process, the original data is always the sole criterion for judging the rationality of the model, ensuring that both forward and inversion models use the original data as a reference constraint, ensuring that model adjustments are in a reasonable and practical direction, and ensuring that the final theoretical data of the model matches the actual data. Consistent with the observed data, a geological structural model was finally obtained. Addressing key technical challenges in the deep structure and sedimentary cover exploration of the Qiangtang Basin, a grid-based magnetotelluric sounding and sedimentary cover inversion study was conducted. Through forward simulation, joint inversion, and intelligent modeling with multi-source fusion, a deep structure-geological structure-geophysical (magnetotelluric) grid profile traversing the "two corridors" of the Qiangtang Basin was constructed, revealing the electrical structure and spatial distribution of the Permian-Neogene sedimentary cover in the basin. This provides a reliable basis for deep structure exploration, resource evaluation, and tectonic evolution research in the Qiangtang Basin. Based on geophysical (magnetotelluric) data, in practical applications, based on the study of the deep structure and spatial distribution of important strata in the Qiangtang Basin, and combined with deep well and deep seismic data, and taking into account the electrical characteristics of the deep structure of the Qiangtang Basin, two deep structure-geological structure-geophysical (magnetotelluric) framework profiles totaling 683 km were established along the Selincuo West-Xiede-Amucuo-Wan'an Lake-Duogecuoren corridor and the Ejiu-Rejuechaka-Qingshui Lake-Tubocuo corridor, supporting the comprehensive exploration and research of deep structure-geological structure-geophysical data.

[0082] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A method for magnetotelluric inversion of the geological structure model of the Qiangtang Basin, characterized in that, Includes the following steps: Determine the management scope of the target Qiangtang Basin, collect existing data within the management scope, construct an initial geological model of the Qiangtang Basin based on the existing data, and store it in the management platform; The steps involved in setting up multiple magnetotelluric observation points within the management area, aggregating these points to form a data acquisition network, and establishing the connection between the data acquisition network and the management platform include: Multiple magnetotelluric observation points were identified within the management area, and their locations were marked on the initial geological model of the Qiangtang Basin. A data acquisition network is configured for multiple magnetotelluric observation points. The data acquisition network includes multiple data acquisition points, the number of which is the same as the number of magnetotelluric observation points and they correspond one-to-one. The receiving network is set up in the management platform for the corresponding data acquisition network. Establish the connection between the data acquisition network and the receiving network in the management platform; Based on the correlation, the raw data collected by the data collection network is provided to the management platform for storage; The process involves processing the raw data to obtain observational data, performing forward modeling calculations based on the initial geological model of the Qiangtang Basin to obtain forward modeling results, comparing the forward modeling results with the observational data, and updating the initial geological model of the Qiangtang Basin through inversion calculations if the difference exceeds a preset value, thus obtaining a geological structural model. This includes the following steps: The raw data is denoised, frequency-domain transformed, and derived parameters are calculated in the management platform to obtain the observation data. The initial geological model of the Qiangtang Basin was forward modeled using the finite difference staggered grid method. The forward modeling results were then compared with the observation data. If the difference exceeded the preset value, the conjugate gradient method was used for iterative inversion to update the initial geological model of the Qiangtang Basin and obtain the geological structure model.

2. The method for magnetotelluric inversion of the geological structure model of the Qiangtang Basin according to claim 1, characterized in that, The steps of determining the management scope of the target Qiangtang Basin, collecting existing data within the management scope, constructing an initial geological model of the Qiangtang Basin based on the existing data, and storing it in the management platform include: The management scope of the target Qiangtang Basin shall be delineated, including both horizontal management scope and stratigraphic depth scope. Existing data within the management area of ​​the Qiangtang Basin are collected, and underground geological bodies within the management area are constructed based on the existing data to obtain an initial geological model of the Qiangtang Basin, which is then stored in the management platform.

3. The method for magnetotelluric inversion of the geological structure model of the Qiangtang Basin according to claim 1, characterized in that, The steps for setting up the receiving network in the management platform for the corresponding acquisition network include: A host computer is configured to correspond to multiple magnetotelluric observation points. The number of acquisition points is set in the storage space of the host computer as the number of magnetotelluric observation points. The acquisition points are bound to the magnetotelluric observation points, and the multiple acquisition points are used as an acquisition network. Multiple encapsulation packets are set for each collection point. Each encapsulation packet consists of a data packet and multiple data units, which are connected to each other. In the management platform, receiver points are configured for the multiple magnetotelluric observation points marked on the initial geological model of the Qiangtang Basin, and these multiple receiver points are used as a receiving network.

4. The method for magnetotelluric inversion of the geological structure model of the Qiangtang Basin according to claim 3, characterized in that, The step of establishing the association between the acquisition network and the receiving network in the management platform includes: Connect the acquisition points and receiving points corresponding to the magnetotelluric observation points, and set an additional channel between the corresponding acquisition points and the corresponding receiving points; Multiple mirroring windows are set between the channel and the supplementary channel. Each mirroring window includes the channel port in the channel, the corresponding image area of ​​the channel port, the supplementary port in the supplementary channel, and the corresponding image area of ​​the supplementary port. Multiple image points are set in the image area.

5. The method for magnetotelluric inversion of the geological structure model of the Qiangtang Basin according to claim 4, characterized in that, The step of providing the raw data collected by the acquisition network to the management platform for storage based on the association relationship includes: The magnetotelluric acquisition equipment set up based on the magnetotelluric observation point collects raw data and timestamps the raw data. The magnetotelluric data acquisition equipment transmits the collected raw data to the corresponding acquisition point in the host computer. It encapsulates the raw data for a preset time period into encapsulated data, and then transmits the encapsulated data through the channel and the additional channel until it is transmitted to the corresponding receiving point of the management platform for storage.

6. The method for magnetotelluric inversion of the geological structure model of the Qiangtang Basin according to claim 5, characterized in that, The step of transmitting the original encapsulated data through the channel and the additional channel until it is transmitted to the receiving point corresponding to the management platform for storage includes: At the collection points, the raw data for the preset time period are determined sequentially according to the collection time. After each preset time period of raw data is collected, a new encapsulation packet is immediately activated. The raw data for the preset time period is stored in the corresponding data packet with the enabled encapsulation packet. Multiple data units are bound to the raw data. Then, the storage address of the data unit in the data packet is determined, and the daisy-chain relationship between the multiple data units is determined. The daisy-chain relationship is a connection architecture composed of the storage addresses of the multiple data units in the data packet and their mutual connection relationship. Based on the hand-holding relationship, multiple data units are copied to obtain the hand-holding group; The original data for the preset time period is backed up on the host computer. The hand-in-hand group and the package containing the original data for the preset time period are transmitted simultaneously. The hand-in-hand group is transmitted through an additional channel, and the package containing the original data for the preset time period is transmitted through the channel. During the transmission, when the package passes through the channel port in the channel, the data unit in the package coincides and connects with the recording point in the recording area. After the recording point is activated, it is immediately disconnected to obtain the recording verification point. When the data unit in the hand-in-hand group reaches the additional port through the additional channel, the data unit in the hand-in-hand group coincides and connects with the recording point in the recording area, and disconnects immediately after the recording point is activated to obtain the recording verification point; The image verification point of the channel port in the mirror window is compared with the image verification point of the additional port. If they cannot be overlapped, it means that the data in the encapsulation packet has changed. The encapsulation packet and the corresponding daisy-chain are destroyed. The original data of the corresponding preset time period in the host computer is resent through the encapsulation packet until the original data of the preset time period is transmitted to the management platform. The original data of the corresponding preset time period in the host computer is then deleted.

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