A method and system for seismic data acquisition and phase correction in a land-ocean transition zone

Abstract

The application discloses a kind of land-sea transition zone seismic data acquisition and phase correction method and system, it is related to geophysical exploration field, the method comprises: in land-sea transition zone, layout source excitation device and signal receiving device;Source excitation device includes controllable source (excitation is carried out in land) and air gun source (excitation is carried out in marine area);Signal receiving device includes node instrument (collects the seismic data of land) and water-land dual-check detector (collects the seismic data of marine area);To seismic data, source difference phase correction is carried out, and the corrected source data body is obtained;To the corrected source data body, detector response difference phase correction is carried out, and the corrected detector data body is obtained.The application can realize the seamless connection of land-sea excitation, and vibration information of water / land medium is captured simultaneously, while the accuracy of seismic data is improved, and then the identification precision of mineral weak reflection signal is improved.

Description

Technical Field

[0001] This application relates to the field of geophysical exploration, and in particular to a method and system for seismic data acquisition and phase correction in the transition zone between land and sea. Background Technology

[0002] Extensive research has been conducted on terrestrial mineral seismic exploration. However, in coastal transition zones, complex geological conditions, numerous interfering factors, seawater cover, and limited construction conditions have obscured effective geophysical signals. Increased exploration depth and weakened differences in the physical properties of minerals and surrounding rocks in shallow sea environments have made mineral detection extremely difficult. How to effectively obtain seismic information in the field and extract weak reflection signals is one of the problems in mineral seismic exploration in coastal areas. Currently, mineral seismic exploration in coastal areas faces the following challenges.

[0003] Complex geological environment: The coastal transition zone is affected by tidal periodic inundation (such as 1-2 tidal changes per day), undulating seabed topography in shallow water areas, underwater obstacles (reefs / shipwrecks), etc., which prevent traditional seismic acquisition equipment (such as towed cable vessels) from operating near the shore, resulting in a gap between marine and land data (usually 200-500 meters).

[0004] Severe signal interference: The significant difference in wave impedance between seawater and the land surface medium causes the excited seismic waves to be reflected multiple times at the interface (sounding effect), masking the weak reflection signal of the gold ore target layer (depth > 800 meters). At the same time, the density / velocity difference between the gold ore body and the surrounding rock in shallow water is only 0.1~0.3 g / cm³, and the effective signal amplitude is 15~20 dB lower than the background noise.

[0005] Phase conflict in multi-source data: Due to differences in excitation mechanisms, the phase difference between the signals received by the same detector from the marine air gun source (dominant frequency 30~80Hz) and the land-based controllable source (dominant frequency 10~60Hz) can reach 120°-150° (measured average 130°). Directly merging the data leads to the break in the in-phase axis and a decrease in the signal-to-noise ratio of the superimposed profile by more than 40%.

[0006] In summary, traditional solutions have limitations: Single-device acquisition: Ocean Bottom Cables (OBCs) must avoid obstacles and cannot cover the intertidal zone; land-based nodal instruments are not suitable for water areas, resulting in data inconsistencies between land and sea. Simplified phase correction processing: Conventional static time-shift or frequency domain filtering cannot eliminate nonlinear phase differences caused by multiple seismic sources and ignores the differences in response characteristics of different detector types (piezoelectric / velocity). Ignoring tidal effects: Most methods do not incorporate tidal cycles into the construction design; during low tide, air-gun boats cannot enter shallow water areas, creating permanent data gaps. Summary of the Invention

[0007] The purpose of this application is to provide a method and system for seismic data acquisition and phase correction in the transition zone between land and sea, which can achieve seamless connection between land and sea excitation, synchronously capture vibration information of water / land media, improve the accuracy of seismic data, and thus enhance the identification accuracy of weak mineral reflection signals.

[0008] To achieve the above objectives, this application provides the following solution:

[0009] Firstly, this application provides a method for seismic data acquisition and phase correction in the land-sea transition zone, including:

[0010] Seismic source excitation devices and signal receiving devices are deployed in the land-sea transition zone. The seismic source excitation device includes a controllable seismic source and an air gun seismic source. The controllable seismic source is used to excite seismic data on land in the land-sea transition zone, and the air gun seismic source is used to excite seismic data in the marine area of ​​the land-sea transition zone. The signal receiving device includes a nodal instrument and a dual-detector (land and sea) geophone. The nodal instrument is used to collect seismic data on land in the land-sea transition zone, and the dual-detector (land and sea) geophone is used to collect seismic data in the marine area of ​​the land-sea transition zone.

[0011] The earthquake is generated in the land-sea transition zone by the source excitation device, and earthquake data is collected by the signal receiving device.

[0012] The earthquake data is subjected to source difference phase correction to obtain the corrected source data volume;

[0013] The corrected source data volume is subjected to detector response difference phase correction to obtain a corrected detector data volume; the corrected detector data volume is used for mineral seismic exploration in the marine-continental transition zone.

[0014] In one embodiment, the seismic data includes data from an air gun source piezoelectric detector, data from an air gun source velocity detector, data from an air gun source nodal instrument, data from a controlled source piezoelectric detector, data from a controlled source velocity detector, and data from a controlled source nodal instrument.

[0015] In one embodiment, source difference phase correction is performed on the seismic data to obtain corrected source data volume, including:

[0016] Using the piezoelectric detector data of the air gun source as a reference, the source difference phase correction is performed on the controllable source piezoelectric detector data, and the corrected controllable source piezoelectric detector data is merged with the air gun source piezoelectric detector data to obtain the piezoelectric detector data body;

[0017] Using the air gun source velocity detector data as a reference, the controllable source velocity detector data is corrected for source difference phase, and the corrected controllable source velocity detector data is merged with the air gun source velocity detector data to obtain the velocity detector data body.

[0018] Based on the air gun source node instrument data, source difference phase correction is performed on the controllable source node instrument data, and the corrected controllable source node instrument data is merged with the air gun source node instrument data to obtain the node instrument data volume.

[0019] The piezoelectric detector data body, the velocity detector data body, and the nodal instrument data body are merged to obtain the source data body;

[0020] Adaptive phase correction is performed on the source data volume to obtain the corrected source data volume.

[0021] In one embodiment, using the air gun source piezoelectric detector data as a reference, source difference phase correction is performed on the controllable source piezoelectric detector data, including: using the air gun source piezoelectric detector data as a reference, performing average phase difference quantization correction and nonlinear phase difference fitting correction sequentially on the controllable source piezoelectric detector data to obtain corrected controllable source piezoelectric detector data.

[0022] In one embodiment, the process of performing average phase difference quantization correction on the controllable source piezoelectric detector data, based on the data from the air gun source piezoelectric detector, includes:

[0023] The first arrival wave signal at the common reflection point of the piezoelectric detector data of the air gun source and the piezoelectric detector data of the controllable source is determined, and the first arrival wave signal of the air gun source and the first arrival wave signal of the controllable source are obtained.

[0024] Hilbert transforms are performed on the first arrival wave signal of the air gun source and the first arrival wave signal of the controllable source respectively to extract the instantaneous phase, thus obtaining the instantaneous phase of the air gun source and the instantaneous phase of the controllable source.

[0025] Calculate the average phase difference between the instantaneous phase of the air gun source and the instantaneous phase of the controllable source;

[0026] The data of the controllable source piezoelectric detector are corrected based on the average phase difference to eliminate the average phase difference caused by source differences.

[0027] In one embodiment, the process of performing nonlinear phase difference fitting correction on the controllable source piezoelectric detector data after average phase difference quantization correction, based on the data from the air gun source piezoelectric detector, includes:

[0028] Based on the data from the piezoelectric detector of the air gun source, an objective function is constructed: ;in, To record the total number of moments within a given time period, for t The instantaneous phase of a controllable seismic source at any given moment. for t The instantaneous phase of the air gun's vibration source at any given moment. for t Phase compensation amount at time;

[0029] The objective function is solved iteratively to obtain the optimal phase compensation amount;

[0030] The controllable source piezoelectric detector data after quantization correction of the average phase difference is corrected according to the optimal phase compensation amount to eliminate the nonlinear phase difference caused by source differences.

[0031] In one embodiment, adaptive phase correction is performed on the source data volume to obtain a corrected source data volume, including: calculating the cross-correlation function of adjacent traces of the source data volume and determining the peak position; dynamically adjusting the phase of the source data volume according to the peak position to obtain the corrected source data volume.

[0032] In one embodiment, the corrected source data volume is subjected to detector response difference phase correction to obtain a corrected detector data volume, including:

[0033] The corrected source data volume is sorted to obtain piezoelectric detector data, velocity detector data, and nodal instrument data.

[0034] Using the piezoelectric detector data as a reference, the velocity detector data is corrected for detector response difference phase, and the corrected velocity detector data is superimposed with the piezoelectric detector data to obtain the first detector merged data;

[0035] Using the first detector merged data as a reference, the node instrument data is subjected to detector response difference phase correction, and the corrected node instrument data is merged with the first detector merged data to obtain the second detector merged data.

[0036] Adaptive phase correction is performed on the combined data from the second detector to obtain the detector data volume;

[0037] Adaptive phase correction is performed on the detector data body to obtain the corrected detector data body.

[0038] In one embodiment, using the piezoelectric detector data as a reference, phase correction of detector response difference is performed on the velocity detector data, including: establishing a transfer function model between the piezoelectric detector data and the velocity detector data; and correcting the phase delay of the velocity detector data by using a deconvolution operation based on the transfer function model.

[0039] Secondly, this application provides a seismic data acquisition and phase correction system for a land-sea transition zone, including: a seismic source excitation device, a signal receiving device, and a phase correction device;

[0040] The seismic source excitation device includes a controllable seismic source and an air gun seismic source. The controllable seismic source is used for excitation on land in the land-sea transition zone, and the air gun seismic source is used for excitation in the marine area of ​​the land-sea transition zone.

[0041] The signal receiving device includes a nodal instrument and a dual-detector (land and sea) geophone. The nodal instrument is used to collect seismic data of the land in the land-sea transition zone, and the dual-detector is used to collect seismic data of the marine area in the land-sea transition zone.

[0042] The phase correction device is used to perform source difference phase correction on the seismic data to obtain the corrected source data volume, and to perform detector response difference phase correction on the corrected source data volume to obtain the corrected detector data volume; the corrected detector data volume is used for mineral seismic exploration in the marine-continental transition zone.

[0043] According to the specific embodiments provided in this application, this application has the following technical effects:

[0044] This application provides a method and system for seismic data acquisition and phase correction in the land-sea transition zone. By using different seismic source excitation devices and signal receiving devices in the land and sea areas, seamless connection between land and sea excitation can be achieved, and vibration information of water / land media can be captured simultaneously. Furthermore, the seismic data is phase corrected by first eliminating the differences between seismic sources and then eliminating the differences between detectors, which improves the accuracy of seismic data and thus enhances the identification accuracy of weak mineral reflection signals. Attached Figure Description

[0045] 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 of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0046] Figure 1 A flowchart illustrating a seismic data acquisition and phase correction method for a land-sea transition zone, provided as an embodiment of this application;

[0047] Figure 2 This is a schematic diagram showing the layout of the seismic source excitation device and the signal receiving device in one embodiment of this application;

[0048] Figure 3 This is a detailed flowchart illustrating the phase correction process in one embodiment of this application;

[0049] Figure 4 This is a block diagram of a seismic data acquisition and phase correction system for a land-sea transition zone, provided as an embodiment of this application. Detailed Implementation

[0050] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0051] This application addresses the challenges posed by tidal dynamics in the transition zone between seawater-covered areas and land, phase inconsistencies in excitation signals from various types of seismic sources, and weakened effective reflection signals in shallow water environments. It proposes a combined sea-land acquisition system and a step-by-step phase correction method, which significantly improves the identification accuracy of weak mineral reflection signals.

[0052] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, the application will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0053] In one exemplary embodiment, such as Figures 1 to 3 As shown, a method for seismic data acquisition and phase correction in the land-sea transition zone is provided, including the following steps 101 to 104.

[0054] Step 101: Deploy seismic source excitation devices and signal receiving devices in the sea-land transition zone.

[0055] The seismic source excitation device includes a controllable seismic source and an air gun seismic source. The controllable seismic source is used for excitation on land in the land-sea transition zone, and the air gun seismic source is used for excitation in the marine area of ​​the land-sea transition zone. The air gun seismic source is an air gun array with a capacity of 2000-4000 inches. 3 The peak force of the controllable seismic source is 28-32 tons, achieving seamless connection between sea and land excitation.

[0056] The signal receiving device includes a nodal point detector and a dual-sensor geophone. The nodal point detector is used to acquire seismic data of the land area in the land-sea transition zone, and the dual-sensor geophone is used to acquire seismic data of the marine area in the land-sea transition zone. The dual-sensor geophone includes a piezoelectric geophone and a velocity geophone. The nodal point detector is a wireless nodal point detector with a sampling rate of 0.5 ms, a dynamic range of 120 dB, and synchronously captures vibration information of both water and land media.

[0057] Furthermore, underwater topographic maps are generated in real time using a multibeam echo sounder 208 → 2m isobaths are drawn → air gun boats operate close to the shore during high tide (tide level > 3m) (50~100 meters from the shoreline), thereby eliminating data gaps caused by tides.

[0058] The surface of the land-sea interface changes with the tides, making seamless integration of land-sea excitation challenging. This application addresses the technical difficulties of airgun excitation in near-shore shallow waters and seamless data acquisition across the land-sea zone. It achieves seamless seismic acquisition from land to shallow waters by employing a controllable land-based source and flexible airgun excitation in extremely shallow and complex waters, along with long-arrayed broadband dual-detection submarine cables and high-density wireless land nodes for joint data acquisition. A multibeam echo sounder (208) is used to precisely scan the water depth and underwater obstacles in the land-sea interface, marking a 2m depth line to provide accurate data guidance for the subsequent safe operation of the airgun source vessel (205). Combining tidal variation data, the tidal patterns and precise timing of the work area, the application rationally utilizes tidal variations, selecting high tide periods for airgun excitation and bringing the airgun source as close to the shore as possible to minimize data gaps.

[0059] like Figure 2 As shown, the OBC towboat 204 and the air gun source vessel 205 are located in shallow water area 201, the multibeam echo sounder 208 is located in transition zone 202, the controllable source vehicle 206 is located on land 203, the OBC dual-detector 209 (piezoelectric detector and velocity detector) is located within the operating range 207 of the air gun source vessel, the water detector 210 (piezoelectric detector) is located in transition zone 202, and the node instrument 211 is located within the operating range 212 of the controllable source vehicle.

[0060] In a specific application example, step 101 includes steps 11 to 19.

[0061] Step 11: Collect marine data to determine the tidal variation patterns and periodic characteristics of the land-sea transition zone.

[0062] Step 12: Use a multibeam echo sounder 208 to precisely measure the water depth in the land-sea interface area and to determine the presence of underwater obstacles.

[0063] Step 13: Draw the critical water depth line (2m water depth line) to determine the construction window when high tide arrives.

[0064] Step 14: Based on the 2D / 3D acquisition design, plan and mark the positions of the marine gun point lines / grids and the receiver point lines / grids.

[0065] Step 15: Arrange the land-based nodal instruments 211 along the survey line or according to the grid to ensure that the coverage area meets the requirements of two-dimensional profile or three-dimensional imaging.

[0066] Step 16: Before the transition from low tide to high tide, accurately arrange the OBC land and water inspections according to the geometric layout of the acquisition design (two-dimensional linear or three-dimensional grid).

[0067] Step 17: The instrument ship and the controllable seismic source vehicle 206 dock in the pre-set direction and position to meet the coverage requirements of the survey line or grid.

[0068] Step 18: Configure a high-precision time synchronization system to synchronize the land and sea seismic sources and ensure that the time difference between the land and sea seismic sources is within a reasonable range.

[0069] Step 19: Calibrate the spatial location and time reference of all receiving points and seismic source points during the 2D / 3D acquisition process.

[0070] Step 102: The seismic source excitation device is used to excite the earthquake in the land-sea transition zone, and the seismic data is collected by the signal receiving device.

[0071] In a specific application example, step 102 includes steps 21 to 28.

[0072] Step 21: When the tide comes, use the multibeam echo sounder 208 to generate an underwater topographic map in real time and monitor the dynamic changes in water depth.

[0073] Step 22: When the tide level exceeds 3m, the air gun source vessel 205 approaches the operating range according to the preset two-dimensional survey line or three-dimensional excitation grid.

[0074] Step 23: For two-dimensional acquisition, the air gun is activated along the predetermined survey line; for three-dimensional acquisition, the air gun is activated according to the grid dot matrix system.

[0075] Step 24: The marine signal receiving device synchronously receives the reflected signal and monitors the data quality and acquisition progress in real time.

[0076] Step 25: After the water area is excited, the controllable seismic source vehicle 206 is started to excite the water area according to the same two-dimensional survey line or three-dimensional grid design within the land operation range.

[0077] Step 26: For two-dimensional acquisition, ensure seamless connection of land and sea survey lines; for three-dimensional acquisition, ensure smooth transition of land and sea grids.

[0078] Step 27: Record the reflected signals to form complete two-dimensional profile data or three-dimensional seismic data volume.

[0079] Step 28: After completing data collection, conduct preliminary quality control to confirm the consistency of collected parameters and the integrity of the data.

[0080] During the acquisition process, two types of seismic sources were used for excitation, and three types of geophones were used for reception, resulting in six different seismic signals. The seismic data includes data from piezoelectric geophones with airgun sources, velocity geophones with airgun sources, nodal point data with airgun sources, piezoelectric geophones with controlled sources, velocity geophones with controlled sources, and nodal point data with controlled sources. The single-shot records from controlled sources and airgun sources show energy phase differences between different geophones. To eliminate the influence of different types of sources and geophones, this application performs phase correction on the seismic data by first eliminating source differences and then eliminating geophone differences. The specific process is as follows: Figure 3 As shown, after amplitude correction, the energy is basically consistent. Based on the energy consistency of single-shot data, phase correction is then performed to eliminate the influence of different types of sources and detectors, thereby improving the accuracy of seismic data.

[0081] Step 103: Perform source difference phase correction on the earthquake data to obtain the corrected source data volume.

[0082] In a specific application example, step 103 includes steps 31 to 35.

[0083] Step 31: Using the piezoelectric detector data of the air gun source as a reference, perform source difference phase correction on the controllable source piezoelectric detector data, and merge the corrected controllable source piezoelectric detector data with the air gun source piezoelectric detector data to obtain the piezoelectric detector data body.

[0084] Specifically, based on the data from the piezoelectric detector of the air gun source, the data from the controllable source piezoelectric detector are sequentially subjected to average phase difference quantization correction and nonlinear phase difference fitting correction to obtain the corrected controllable source piezoelectric detector data.

[0085] The process of quantizing and correcting the average phase difference includes the following steps (11) to (14).

[0086] (11) Determine the first arrival wave signal of the common reflection point of the piezoelectric detector data of the air gun source and the piezoelectric detector data of the controllable source, and obtain the first arrival wave signal of the air gun source and the first arrival wave signal of the controllable source.

[0087] (12) Perform Hilbert transform on the first arrival wave signal of the air gun source and the first arrival wave signal of the controllable source respectively to extract the instantaneous phase: The instantaneous phase of the air gun source and the instantaneous phase of the controllable source were obtained. fort The instantaneous phase of a moment, for t Seismic data at any given time (data received by the detector). This represents the Hilbert transform.

[0088] (13) Calculate the average phase difference between the instantaneous phase of the air gun source and the instantaneous phase of the controllable source (measured value 130±10°): .in, The average phase difference is the mean value. for t The instantaneous phase of a controllable seismic source at any given moment. for t The instantaneous phase of the air gun's seismic source at any given moment.

[0089] (14) Correct the data of the controllable source piezoelectric detector according to the average phase difference to eliminate the average phase difference caused by the source difference.

[0090] The process of nonlinear phase difference fitting correction includes the following steps (21) to (23).

[0091] (21) Based on the data from the piezoelectric detector of the air gun source, construct the objective function: ;in, To record the total number of moments within a given time period, for t Phase compensation amount at any given time.

[0092] (22) The objective function is solved iteratively to obtain the optimal phase compensation amount.

[0093] The specific iterative solution steps are as follows.

[0094] ① Construct a phase compensation model ;in, For parameter vectors, , As the first parameter, This is the second parameter.

[0095] ② Define residuals : .

[0096] ③ Calculate the residual vector :

[0097] .

[0098] Among them, superscript k =0, 1, 2… indicates the iteration number; subscripts 1, 2, 3… N Indicates different sampling times.

[0099] ④ Calculate the Jacobian matrix : .

[0100] ⑤ Construct the normal equation: .

[0101] ⑥ Solve for parameter update amount : .

[0102] ⑦ Update parameter estimates: .

[0103] ⑧ Convergence judgment: If or Then stop iterating. To set the threshold for stopping iterations, the optimal solution is output as follows: .

[0104] ⑨ Output phase compensation amount: .

[0105] (23) Correct the controllable source piezoelectric detector data after the average phase difference quantization correction according to the optimal phase compensation amount, so as to eliminate the nonlinear phase difference caused by the source difference.

[0106] Step 32: Using the air gun source velocity detector data as a reference, perform source difference phase correction on the controllable source velocity detector data, and merge the corrected controllable source velocity detector data with the air gun source velocity detector data to obtain the velocity detector data body.

[0107] Step 33: Using the air gun source node data as a reference, perform source difference phase correction on the controllable source node data, and merge the corrected controllable source node data with the air gun source node data to obtain the node data volume.

[0108] In this application, the source difference phase correction process in steps 32 and 33 is the same as the source difference phase correction process in step 31, and will not be described again here.

[0109] Step 34: Combine the data of the piezoelectric detector, the data of the velocity detector, and the data of the nodal instrument to obtain the source data.

[0110] Step 35: Perform adaptive phase correction on the source data volume to obtain the corrected source data volume.

[0111] Specifically, the cross-correlation function between adjacent traces of the source data volume is calculated: And determine the peak position .in, For source data volume, The cross-correlation function value, taking values ​​in the range [0,1], is used to measure the similarity between two adjacent channels. =0 indicates the similarity when the two seismic traces are perfectly aligned. >0 indicates that Shift to the right After sampling points, then... Do the inner product. <0 indicates that Move left | |Sampling points and then Do the inner product. express relatively The maximum similarity is denoted by a value of 1, which indicates complete correlation, and a value of 0, which indicates complete irrelevance.

[0112] The phase of the source data volume is dynamically adjusted based on the peak position to obtain the corrected source data volume. Find the... of The value is the correction value for that seismic trace.

[0113] Step 104: Perform detector response difference phase correction on the corrected source data volume to obtain a corrected detector data volume. The corrected detector data volume is used for mineral seismic exploration in the marine-continental transition zone.

[0114] In a specific application example, step 104 includes steps 41 to 45.

[0115] Step 41: The corrected source data volume is sorted to obtain piezoelectric detector data, velocity detector data and nodal instrument data.

[0116] This application can be used for two-dimensional seismic exploration in the transition between land and sea. Therefore, the piezoelectric detectors, velocity detectors, and nodal points are arranged linearly, each corresponding to a unique station number, which can be used for screening. Among them, the land-sea dual-detector system has both piezoelectric and velocity detectors at the same point, which need to be distinguished when designing the station number. For example, piezoelectric detector: M10001, velocity detector: G10001, indicating two different detectors at the first point of the first survey line.

[0117] Step 42: Using the piezoelectric detector data as a reference, perform detector response difference phase correction on the velocity detector data, and superimpose the corrected velocity detector data with the piezoelectric detector data to obtain the first detector merged data.

[0118] Specifically, the process of phase correction for detector response difference is as follows: A transfer function model is established between the piezoelectric detector data and the velocity detector data: .in, To pass function values, For piezoelectric detector data, Here, f represents the velocity detector data, and f is the frequency. Based on the transfer function model, a deconvolution operation is used to correct the phase delay of the velocity detector data: .in, for t The velocity detector data after time correction This indicates the deconvolution operation. Represents the Fast Fourier Transform. This represents the inverse fast Fourier transform.

[0119] Step 43: Using the first detector merged data as a reference, perform detector response difference phase correction on the node instrument data, and merge the corrected node instrument data with the first detector merged data to obtain the second detector merged data.

[0120] In this application, the detector response difference phase correction process in step 43 is the same as the detector response difference phase correction process in step 42, and will not be described again here.

[0121] Step 44: Perform adaptive phase correction on the merged data of the second detector to obtain the detector data body.

[0122] Step 45: Perform adaptive phase correction on the detector data body to obtain the corrected detector data body.

[0123] In this application, the adaptive phase correction process in step 45 is the same as the adaptive phase correction process in step 35, and will not be described again here.

[0124] Phase testing revealed that the phase difference between data from the same geophone with different sources was -130°, and the difference between data from different geophones with the same source was also -130°. Therefore, this application uses data from an air gun source as a basis, performs phase rotation on the piezoelectric, velocity, and nodal data of a controllable source, and then superimposes them. After testing, the phase axis continuity with a phase rotation of -130° is strong, and the superposition effect is the best, which is used as the final parameter for phase rotation.

[0125] The controllable source piezoelectric detector and the air gun source piezoelectric detector have a phase difference of -130 degrees, and the superposition effect is good. Then, adaptive phase correction is performed on the two detectors, which has a better effect and better continuity of the phase axis.

[0126] The controllable source velocity detector and the air gun source velocity detector, with a phase difference of -130 degrees, have a good superposition effect. After that, adaptive phase correction is performed on the two detectors, which has a better effect and better continuity of the phase axis.

[0127] The controllable source node instrument and the air gun source node instrument have a phase difference of -130 degrees, and the superposition effect is good. After that, adaptive phase correction is performed on the two detectors, and the effect is even better, and the continuity of the phase axis is better.

[0128] Phase tests were conducted on different detectors for two types of seismic sources. The OBC (piezoelectric, velocity) and node signals excited by the controlled source differed from those received by the detector excited by the air gun by -130°. After adaptive phase correction, the obtained profile imaging effect was better. After rotating the phase of the velocity detector by -130 degrees, the in-phase axis of the profile was consistent with that of the piezoelectric detector.

[0129] After phase correction and merging, the superposition effect test showed that the piezoelectric + velocity detector rotated -130 degrees + adaptive phase correction results in good phase axis continuity and the highest signal-to-noise ratio, indicating that it is a phase superposition.

[0130] After the dual detection was combined, the notch phenomenon in the profile spectrum analysis was significantly improved, and the vibration interference on the profile was suppressed.

[0131] Finally, the merged data from the dual detection was combined with the data after the node phase was rotated by -130 degrees and adaptive phase correction was applied. The internal reflection characteristics were clear and the signal-to-noise ratio was high.

[0132] In summary, this application employs different seismic source excitation devices and signal receiving devices in land and sea areas, enabling seamless integration of land and sea excitation and simultaneous capture of vibration information from water / land media. Furthermore, by first eliminating differences in seismic sources and then eliminating differences in geophones, phase correction is performed on the seismic data, improving the accuracy of the seismic data and thus enhancing the identification accuracy of weak mineral reflection signals.

[0133] This application also provides an application scenario in which the above-mentioned seismic data acquisition and phase correction method for land-sea transition zones is applied. Specifically, the seismic data acquisition and phase correction method for land-sea transition zones provided in this embodiment can be applied to the seismic exploration scenario of onshore gold mines. In onshore gold mine seismic exploration, seismic data is acquired using the seismic data acquisition and phase correction method for land-sea transition zones, and after the seismic data is corrected, the seismic exploration of onshore gold mines is achieved based on the corrected detector data.

[0134] Based on the same inventive concept, this application also provides a system for implementing the methods described above. The solution provided by this system is similar to the solution described in the above methods. Therefore, the specific limitations of one or more embodiments of the seismic data acquisition and phase correction system for land-sea transition zones provided below can be found in the limitations of the seismic data acquisition and phase correction method for land-sea transition zones described above, and will not be repeated here.

[0135] In one exemplary embodiment, such as Figure 4 As shown, a seismic data acquisition and phase correction system for a land-sea transition zone is provided, comprising: a seismic source excitation device 401, a signal receiving device 402, and a phase correction device 403.

[0136] The seismic source excitation device 401 includes a controllable seismic source and an air gun seismic source. The controllable seismic source is used for excitation on land in the land-sea transition zone, and the air gun seismic source is used for excitation in the marine area of ​​the land-sea transition zone.

[0137] The signal receiving device 402 includes a node instrument and a land-sea dual-detector. The node instrument is used to collect seismic data of the land in the land-sea transition zone, and the land-sea dual-detector is used to collect seismic data of the marine area in the land-sea transition zone.

[0138] The phase correction device 403 is used to perform source difference phase correction on the seismic data to obtain corrected source data volume, and then performs detector response difference phase correction on the corrected source data volume to obtain corrected detector data volume. The corrected detector data volume is used for mineral seismic exploration in the marine-continental transition zone.

[0139] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, data stored, data displayed, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties, and the collection, use and processing of the relevant data must comply with relevant regulations.

[0140] In this application, all actions to acquire signals, information, or data are carried out in compliance with the relevant data protection laws and policies of the country where the location is situated, and with the authorization granted by the owner of the relevant device.

[0141] The technical features of the above embodiments can be combined in any way. For the sake of brevity, 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.

[0142] This document uses specific examples to illustrate the principles and implementation methods of this application. The descriptions of the above embodiments are only for the purpose of helping to understand the methods and core ideas of this application. Furthermore, those skilled in the art will recognize that, based on the ideas of this application, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A method for land transition zone seismic data acquisition and phase correction, the method comprising: The method includes: A seismic source excitation device and a signal receiving device are deployed in the land-sea transition zone. The seismic source excitation device includes a controllable seismic source and an air gun seismic source. The controllable seismic source is used to excite seismic data on land in the land-sea transition zone, and the air gun seismic source is used to excite seismic data in the marine area of ​​the land-sea transition zone. The signal receiving device includes a nodal point detector and a dual-detector (land and water). The nodal point detector is used to collect seismic data on land in the land-sea transition zone, and the dual-detector (land and water) is used to collect seismic data in the marine area of ​​the land-sea transition zone. The seismic data includes data from the air gun seismic source piezoelectric detector, air gun seismic source velocity detector, air gun seismic source nodal point detector, controllable seismic source piezoelectric detector, controllable seismic source velocity detector, and controllable seismic source nodal point detector. The earthquake is generated in the land-sea transition zone by the source excitation device, and earthquake data is collected by the signal receiving device. The seismic data is subjected to source difference phase correction to obtain the corrected source data volume, which includes: Using the piezoelectric detector data of the air gun source as a reference, the source difference phase correction is performed on the controllable source piezoelectric detector data, and the corrected controllable source piezoelectric detector data is merged with the air gun source piezoelectric detector data to obtain the piezoelectric detector data body; Using the air gun source velocity detector data as a reference, the controllable source velocity detector data is corrected for source difference phase, and the corrected controllable source velocity detector data is merged with the air gun source velocity detector data to obtain the velocity detector data body. Based on the air gun source node instrument data, source difference phase correction is performed on the controllable source node instrument data, and the corrected controllable source node instrument data is merged with the air gun source node instrument data to obtain the node instrument data volume. The piezoelectric detector data body, the velocity detector data body, and the nodal instrument data body are merged to obtain the source data body; Adaptive phase correction is performed on the source data volume to obtain the corrected source data volume; The corrected source data volume is subjected to detector response difference phase correction to obtain a corrected detector data volume; the corrected detector data volume is used for mineral seismic exploration in the marine-continental transition zone.

2. The method of land transition zone seismic data acquisition and phase correction of claim 1, wherein, Using the data from the piezoelectric detector of the air gun source as a reference, source difference phase correction is performed on the data from the controllable source piezoelectric detector, including: Using the piezoelectric detector data of the air gun source as a reference, the controllable source piezoelectric detector data is sequentially subjected to average phase difference quantization correction and nonlinear phase difference fitting correction to obtain the corrected controllable source piezoelectric detector data.

3. The method of claim 2, wherein, The process of performing average phase difference quantization correction on the controllable source piezoelectric detector data, based on the data from the piezoelectric detector of the air gun source, includes: The first arrival wave signal at the common reflection point of the piezoelectric detector data of the air gun source and the piezoelectric detector data of the controllable source is determined, and the first arrival wave signal of the air gun source and the first arrival wave signal of the controllable source are obtained. respectively, and extract the instantaneous phase to obtain the air gun instantaneous phase and the vibrator instantaneous phase; calculate the average phase difference between the air gun instantaneous phase and the vibrator instantaneous phase; correct the vibrator piezoelectric detector data according to the average phase difference to eliminate the average phase difference caused by the source difference.

4. The method of claim 3, wherein, The process of nonlinear phase difference fitting correction of the vibrator piezoelectric detector data after the average phase difference quantitative correction includes: Based on the data from the piezoelectric detector of the air gun source, an objective function is constructed: ;in, To record the total number of moments within a given time period, for t The instantaneous phase of a controllable seismic source at any given moment. for t The instantaneous phase of the air gun's vibration source at any given moment. for t Phase compensation amount at any given time; iteratively solve the objective function to obtain the optimal phase compensation; correct the vibrator piezoelectric detector data after the average phase difference quantitative correction according to the optimal phase compensation to eliminate the nonlinear phase difference caused by the source difference.

5. The method of claim 2, wherein, The adaptive phase correction of the source data volume includes: calculate the cross-correlation function of adjacent channels of the source data volume and determine the peak position; dynamically adjust the phase of the source data volume according to the peak position to obtain the corrected source data volume.

6. The method of land transition zone seismic data acquisition and phase correction of claim 1, wherein, The geophone response difference phase correction of the corrected source data volume includes: sort the corrected source data volume to obtain piezoelectric detector data, velocity detector data and node instrument data; correct the velocity detector data according to the piezoelectric detector data, and superimpose the corrected velocity detector data and the piezoelectric detector data to obtain first geophone merged data; correct the node instrument data according to the first geophone merged data, and merge the corrected node instrument data and the first geophone merged data to obtain second geophone merged data; perform adaptive phase correction on the second geophone merged data to obtain a geophone data volume; perform adaptive phase correction on the geophone data volume to obtain a corrected geophone data volume.

7. The method of land transition zone seismic data acquisition and phase correction of claim 6, wherein, The geophone response difference phase correction of the velocity detector data according to the piezoelectric detector data includes: establish a transfer function model between the piezoelectric detector data and the velocity detector data; correct the phase delay of the velocity detector data by using deconvolution operation according to the transfer function model.

8. A land-sea transition zone seismic data acquisition and phase correction system, characterized by, The system is applied to the marine-terrestrial transition zone seismic data acquisition and phase correction method in any one of claims 1-7, and the system includes a source excitation device, a signal receiving device and a phase correction device; The source excitation device includes a vibrator and an air gun source, the vibrator is used for excitation on land in the marine-terrestrial transition zone, and the air gun source is used for excitation in the marine area of the marine-terrestrial transition zone; The signal receiving device includes a node instrument and a water-land dual detection geophone, the node instrument is used for collecting seismic data on land in the marine-terrestrial transition zone, and the water-land dual detection geophone is used for collecting seismic data in the marine area of the marine-terrestrial transition zone; The phase correction device is used for source differential phase correction on the seismic data to obtain a corrected source data volume, and geophone response differential phase correction on the corrected source data volume to obtain a corrected geophone data volume; and the corrected geophone data volume is used for mineral seismic exploration on the sea-land transition zone.

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