CN108957525B - Continuous recording method for seismic data acquisition - Google Patents
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Abstract
The invention relates to the field of seismic exploration and discloses a continuous recording method for seismic data acquisition. The method comprises the following steps: continuously recording original seismic signals to form an original recording file; receiving a plurality of navigation headers corresponding to the original recording file; according to the recording length required by acquisition and the sound shot time in each navigation head section in the navigation head sections, dividing the original recording file to form an aliasing recording file with the starting time and the duration consistent with the sound shot time of the navigation head section and the recording length required by acquisition aiming at the navigation head sections, wherein the aliasing recording file comprises the aliasing recording of seismic signals excited by two sound shots; and separating the aliasing record file, and outputting the separated conventional seismic record under the condition that the residual crosstalk noise and the effective wave leakage in the separated conventional seismic record are lower than corresponding preset values.
Description
Technical Field
The invention relates to seismic exploration, in particular to a continuous recording method for seismic data acquisition.
Background
With the continuous development of the petroleum industry, the target of shallow layer easy exploration is less and less, and the national energy development strategy gradually turns to new, difficult and deep fields, so the difficulty and complexity of seismic oil-gas exploration are continuously increased, and more urgent requirements are provided for seismic exploration in complex areas and deeper layers. Generally, seismic images acquired in complex geological structure environments are blurred, but high-quality seismic images can be acquired by using new marine seismic technologies, so that exploration risks are reduced. In recent years, the appearance of new streamer acquisition technologies, such as a Q-Marine high-precision acquisition technology, a broadband acquisition technology, a wide-azimuth acquisition technology and an all-dimensional acquisition technology, has a good effect of improving the quality of seismic data. In conventional streamer seismic acquisition, a navigation trigger recording mode is generally adopted for acquisition (as shown in fig. 1), and after recording is completed, navigation trigger resetting is carried out to prepare for triggering recording of the next shot, so that the next shot cannot sound before recording of one shot is completed, and otherwise, a shot losing phenomenon can be generated. In this case, the recording length and the shot density are not compatible. In the conventional operation, under the condition of constant operation speed, the recording length determines the minimum shot spacing, and the quality of data is influenced by the spatial shot density.
In the operation of multi-ship-width directions, the single-source spacing is too large, the space shot density is insufficient, and the data quality is influenced; by adopting a traditional acquisition mode, a navigation system of a main ship sends a gun control trigger signal to a seismic source of the main ship or an auxiliary seismic source ship, and the auxiliary seismic source ship is generally communicated with the main ship through wireless transmission equipment. The seismic source system needs to send a seismic source head section to a navigation system of a main ship in real time, the navigation system sends the combined navigation head section to an instrument recording system through a serial port, the process requires that wireless communication between the main ship and an auxiliary seismic source ship is smooth, and otherwise, cannons are easily lost.
Disclosure of Invention
The invention aims to provide a continuous recording method for seismic data acquisition, which can solve the contradiction between the operation efficiency, the shot density and the recording length, can obtain more dense spatial shot point distribution on the premise of not influencing the construction efficiency and is beneficial to improving the quality of seismic data.
In order to achieve the above object, the present invention provides a continuous recording method of seismic data acquisition, the continuous recording method comprising: continuously recording original seismic signals to form an original recording file; receiving a plurality of navigation headers corresponding to the original recording file; according to the recording length required by acquisition and the sound shot time in each navigation head section in the navigation head sections, dividing the original recording file to form an aliasing recording file with the starting time and the duration consistent with the sound shot time of the navigation head section and the recording length required by acquisition aiming at the navigation head sections, wherein the aliasing recording file comprises the aliasing recording of seismic signals excited by two sound shots; and separating the aliasing record file, and outputting the separated conventional seismic record under the condition that the residual crosstalk noise and the effective wave leakage in the separated conventional seismic record are lower than corresponding preset values.
Optionally, the aliasing record file is separated again when the residual crosstalk noise and the effective wave leakage in the separated conventional seismic record are higher than corresponding preset values.
Optionally, the navigation header includes shot time, shot number, and line name.
Optionally, when a communication fault occurs after a cannon or cannons sound, the corresponding navigation head segment cannot be received, but the corresponding original seismic signals are continuously recorded at the set time interval, so as to form a corresponding original recording file; and when the communication is recovered to be normal, receiving the corresponding navigation head segment.
Optionally, the alias record file includes: active signal and crosstalk noise.
Optionally, the separating the alias recording file includes: extracting the effective signal in the aliasing record file, and taking a signal after the effective signal is separated from the aliasing record file as the crosstalk noise; establishing a crosstalk noise model according to the crosstalk noise, the shot time and the seismic source wavelet information; and subtracting the crosstalk noise model from the aliased record file to obtain a conventional seismic record.
Optionally, the significant wave leakage is obtained by matching the separated conventional seismic record with the significant signal.
Optionally, the original recording file comprises an SEGD recording file.
Accordingly, the present invention also provides a storage medium storing a computer program configured to execute the above-described continuous recording method.
Through the technical scheme, the continuous recording method adopted by the invention can obtain more dense spatial shot point distribution on the premise of not influencing the construction efficiency, is favorable for improving the seismic data quality, and can give consideration to the shot spacing, the recording length and the operation efficiency.
Drawings
FIG. 1 is a diagram illustrating a conventional navigation trigger mode recording manner;
FIG. 2 is a flow chart of a method for continuous recording of seismic data acquisition provided by one embodiment of the present invention;
FIG. 3 is a schematic illustration of a continuous recording mode of seismic data acquisition provided by one embodiment of the present invention; and
FIG. 4 is a flow chart of a method for continuous recording of seismic data acquisition according to one embodiment of the invention.
Description of the reference numerals
1 navigation header 2 SEGD recording file
3 first cannon 4 second cannon
5 third gun 6 navigation head section
7-second pulse signal 8 SEGD recording file
9 navigation header 10 alias record file
11 first cannon 12 second cannon
13 third cannon 14 fourth cannon
Detailed Description
The following detailed description of embodiments of the invention refers to the accompanying drawings. It should be understood that the detailed description and specific examples, while indicating the present invention, are given by way of illustration and explanation only, not limitation.
The continuous recording process of seismic data acquisition in the invention is explained by taking multi-ship-width azimuth operation as an example, and a navigation system of a main ship in the multi-ship-width azimuth operation sends gun control trigger signals to an auxiliary seismic source ship (or a seismic source of the main ship); the auxiliary seismic source ship immediately rings a gun and sends a gun array head section once receiving the trigger signal; and the navigation system receives the gun array head section, combines the gun array head section with information such as gun time, gun number and the like into a navigation head section, and transmits the navigation head section to a continuous recording system through FTP protocol transmission.
FIG. 2 is a flow chart of a method for continuous recording of seismic data acquisition according to one embodiment of the present invention. As shown in fig. 2, the continuous recording method may include: continuously recording original seismic signals to form an original recording file; receiving a plurality of navigation headers corresponding to the original recording file; according to the recording length required by acquisition and the sound shot time in each navigation head section in the navigation head sections, dividing the original recording file to form an aliasing recording file with the starting time and the duration consistent with the sound shot time of the navigation head section and the recording length required by acquisition aiming at the navigation head sections, wherein the aliasing recording file comprises the aliasing recording of seismic signals excited by two sound shots; and separating the aliasing record file, and outputting the separated conventional seismic record under the condition that the residual crosstalk noise and the effective wave leakage in the separated conventional seismic record are lower than corresponding preset values. The continuous recording method can obtain more dense spatial shot point distribution on the premise of not influencing the construction efficiency, is favorable for improving the seismic data quality, and can give consideration to the shot distance, the recording length and the operation efficiency.
The navigation head section can comprise shot time, shot number, line name and the like. When a communication fault occurs after a cannon or cannons sound, the corresponding navigation head segment cannot be received, but the corresponding original seismic signals are continuously recorded at the set time interval to form a corresponding original recording file; and when the communication is recovered to be normal, receiving the corresponding navigation head segment. Under the very big condition of traditional many boats and ships operation big gun density, cause communication fault very easily, and then lead to the unable real-time transmission of the corresponding navigation head section of certain big gun or some big guns to traditional record instrument, corresponding seismic signal just can not be recorded to traditional record instrument, can produce promptly and lose the big gun problem. The continuous recording mode in the invention can ensure that the original recording file of a certain cannon or a plurality of cannons is still recorded when the communication is failed, and the navigation head section corresponding to the original recording file can be continuously received when the communication is recovered to be normal, namely, the navigation head section does not need to be transmitted in real time, thereby solving the cannon losing problem caused by the communication failure, saving the time and improving the construction efficiency.
The original recording file can comprise an SEGD recording file and an SEGY recording file, and the number of seismic channels or the acquisition parameters can be changed midway in one recording process, namely the number of seismic channels or the acquisition parameters between two adjacent cannons are changed, so that the SEGD recording file with a more flexible recording mode is adopted.
The alias log file may include: active signal and crosstalk noise. As shown in fig. 3, each time the seismic signal fired by a cannon corresponds to an aliasing record file, the aliasing record file contains effective signals in the seismic signal fired by each cannon and aliasing records of the seismic signals fired by two adjacent cannons, namely crosstalk noise. For example, the aliasing record file corresponding to the first shot 11 records the effective signal in the seismic signal excited by the first shot 11, and the tail part records the signal of the seismic signal excited by the second shot 12, where the signal of the seismic signal excited by the first shot 11 and the second shot 12 together is crosstalk noise in the first shot 11. Due to the randomness of the time of the aliasing cannon set cannon, the crosstalk noise is a random spike noise signal; and the valid signal is a continuous coherency signal.
The separating the aliased record file comprises: extracting the effective signals in the aliasing record file, and taking signals after the aliasing record file is separated from the effective signals as the crosstalk noise; establishing a crosstalk noise model according to the crosstalk noise, the shot time and the seismic source wavelet information; and subtracting the crosstalk noise model from the aliased record file to obtain a conventional seismic record. In fact, on the one hand, since the crosstalk noise model may include a part of the effective signal in addition to the crosstalk noise, the obtained conventional seismic record may lose the part of the effective signal. Wherein the portion of the valid signal is referred to as valid leakage. On the other hand, since the crosstalk noise model does not exactly match the actual crosstalk noise, the conventional seismic records include residual crosstalk noise in addition to the valid seismic signals.
And performing cross correlation on the residual crosstalk noise and the crosstalk noise model reconstructed by using the method, detecting whether the correlation value is lower than a set value, and if the correlation value is lower than the set value, considering that the residual crosstalk noise is minimized. In detecting the remaining crosstalk noise in the conventional seismic record, it is also necessary to detect valid leaks of the conventional seismic record. Wherein the significant wave leakage is obtainable by matching the separated conventional seismic record with the significant signal. Outputting the separated conventional seismic signals under the condition that the residual crosstalk noise and the effective leakage are lower than corresponding preset values; and under the condition that the residual crosstalk noise and the effective wave leakage are higher than corresponding preset values, re-separating the aliasing record files until the residual crosstalk noise and the effective wave leakage are lower than the corresponding preset values, and outputting the separated conventional seismic records. The process of minimizing the leakage of the desired waves and the residual crosstalk noise is to minimize the crosstalk noise in the conventional seismic records and to ensure that the desired waves are not damaged.
Specifically, the process of continuous recording of marine seismic data acquisition is now explained by taking as an example a main vessel and an auxiliary source vessel in multi-vessel wide azimuth operation.
As shown in fig. 3, the navigation system of the host vessel records time using Pulse Per Second (PPS)7, and the continuous recording system needs to use the same time reference as the navigation system to ensure time consistency. The navigation system of the main ship triggers a gun control system on the auxiliary seismic source ship to make a sound, receives multiple gun array head section information from the gun control system sound, combines the multiple gun array head section information, sound time and gun number into multiple navigation head sections 9, and transmits the multiple navigation head sections 9 through an FTP protocol.
The continuous recording system records time based on the pulse-per-second signal 7 of the navigation system, continuously records original seismic signals at set time intervals (such as 5s) in the SEGD recording mode, forms an original SEGD recording file 8 with fixed length, and receives the navigation head segments 9. Once the continuous recording system receives the navigation headers, the original SEGD recording file 8 is divided according to the shot time in each of the navigation headers in the navigation headers 9 according to the recording length required for acquisition (e.g., 12s) to form an alias recording file with a start time and duration consistent with the shot time of the navigation header and the recording length required for acquisition for the navigation headers 9. That is, a recording file of a recording length of 12s thereafter is intercepted, starting from the point in time of the sound shot of the corresponding first shot 11 in the original SEGD recording file 8; intercepting a recording file with the recording length of 12s from the sound shot time point of the corresponding second shot 12 in the original SEGD recording file 8; the same is true for the processing of the third shot 13, the fourth shot 14, etc., which will not be described in detail herein. Finally, each segment record file is then merged with the corresponding navigation header to form an aliased record file 10. In the aliased record file 10, the shot time of the second shot 12 occurs during the recording of the first shot 11, so that the two shot records overlap at the tail of the record file of the first shot 11. On the premise of not influencing the construction efficiency, more dense spatial shot point distribution can be obtained, and the improvement of the seismic data quality is facilitated.
If a communication fault occurs after the third cannon rings, for example, a communication fault occurs between the navigation system and the continuous recording system, the navigation system cannot transmit a navigation head section corresponding to the third cannon, and although the continuous recording system cannot receive the navigation head section corresponding to the third cannon, the continuous recording system continuously records original seismic signals corresponding to the third cannon at the set time interval of 5s, so that a corresponding original SEGD recording file is formed; and when the communication is recovered to be normal, the navigation system can continuously transmit the corresponding navigation head segment to the continuous recording system. For a traditional recording mode, because the navigation system needs to transmit the navigation head section to a traditional recording instrument in real time, if a communication fault occurs after the third cannon sounds, the navigation system cannot transmit the navigation head section corresponding to the third cannon to the traditional recording instrument, the traditional recording instrument cannot record the original seismic signal corresponding to the third cannon, and the original seismic signal corresponding to the third cannon is lost. The navigation head section does not need to be transmitted in real time, so that the problem of shot loss caused by communication faults can be solved, the time is saved, and the construction efficiency is improved.
As shown in fig. 4, the aliased record file is separated to output a separated conventional seismic record. Extracting effective signals in the aliasing record file at a common detector domain in the continuous recording system, and taking signals after the aliasing record file is separated from the effective signals as the crosstalk noise; reconstructing a crosstalk noise model by using the crosstalk noise, the shot time and the far-field wavelet information of the seismic source; the crosstalk noise model is then subtracted from the aliased record file to obtain a conventional seismic record. And then, detecting whether the energy of the residual crosstalk noise is lower than a preset value, matching the conventional seismic record with the extracted effective signal, and detecting whether the effective wave leakage is lower than the preset value. Outputting the separated conventional seismic record under the condition that the residual crosstalk noise and the effective leakage are lower than corresponding preset values; otherwise, continuously repeating the operation of separating the aliasing record file until the residual crosstalk noise and the effective wave leakage are lower than corresponding preset values, and outputting the separated conventional seismic record. The process of minimizing the leakage of the desired waves and the residual crosstalk noise is to minimize the crosstalk noise in the conventional seismic records and to ensure that the desired waves are not damaged.
The continuous recording method in the present invention is not limited to the case of the multi-beam azimuth work in the present embodiment, and is also applicable to the normal work.
The continuous recording method for seismic data acquisition is adopted when seismic acquisition is carried out in a certain area of the east sea in the end of 2015 and in 8 months in 2017 and multi-ship inclined cable wide-bandwidth azimuth three-dimensional seismic acquisition is carried out. By using the method, the shot distance is reduced to 18.75 meters from 25 meters in the conventional recording mode, and the coverage times of the seismic sources are improved by 33 percent under the same operation condition.
In conclusion, the invention can obtain more dense spatial shot point distribution on the premise of not influencing the construction efficiency, and is beneficial to improving the quality of seismic data; the navigation head section does not need to be transmitted in real time, the problem of cannon losing caused by communication faults is solved, time is saved, construction efficiency is improved, and cannon spacing, recording length and operation efficiency are considered. Accordingly, the present invention also provides a storage medium storing a computer program configured to execute the above-described continuous recording method.
The preferred embodiments of the present invention have been described in detail with reference to the accompanying drawings, however, the present invention is not limited to the specific details of the above embodiments, and various simple modifications can be made to the technical solution of the present invention within the technical idea of the present invention, and these simple modifications are within the protective scope of the present invention.
It should be noted that the various features described in the above embodiments may be combined in any suitable manner without departing from the scope of the invention. The invention is not described in detail in order to avoid unnecessary repetition.
In addition, any combination of the various embodiments of the present invention is also possible, and the same should be considered as the disclosure of the present invention as long as it does not depart from the spirit of the present invention.
Claims (7)
1. A continuous recording method for seismic data acquisition, applied to marine streamer operation, the continuous recording method comprising:
continuously recording original seismic signals to form an original recording file;
receiving a plurality of navigation headers corresponding to the original recording file;
according to the recording length required by acquisition and the sound shot time in each navigation head section in the navigation head sections, dividing the original recording file to form an aliasing recording file with the starting time and the duration consistent with the sound shot time of the navigation head section and the recording length required by acquisition aiming at the navigation head sections, wherein the aliasing recording file comprises the aliasing recording of seismic signals excited by two sound shots; and
separating the aliasing record file, outputting the separated conventional seismic record under the condition that the residual crosstalk noise and the effective wave leakage in the separated conventional seismic record are lower than corresponding preset values,
wherein the alias log file comprises: the effective signal and the cross-talk noise,
accordingly, the separating the aliased record file comprises:
extracting the effective signals in the aliasing record file, and taking signals after the aliasing record file is separated from the effective signals as the crosstalk noise;
establishing a crosstalk noise model according to the crosstalk noise, the shot time and the seismic source wavelet information; and
subtracting the crosstalk noise model from the aliased record file to obtain a conventional seismic record.
2. The continuous recording method according to claim 1, wherein the aliased record file is re-separated in case the residual crosstalk noise and the significant wave leakage in the separated conventional seismic records are higher than the respective preset values.
3. The continuous recording method according to claim 1, wherein the navigation header includes shot time, shot number, and line name.
4. The continuous recording method according to claim 1, wherein when a communication failure occurs after a shot or shots are fired, the corresponding navigation head segment is not received, and corresponding original seismic signals are continuously recorded at set time intervals to form corresponding original recording files; and when the communication is recovered to be normal, receiving the corresponding navigation head segment.
5. The continuous recording method according to claim 1, wherein the significant wave leakage is obtained by matching the separated conventional seismic records with the significant signal.
6. The continuous recording method as claimed in claim 1, wherein the original recording file comprises an SEGD recording file.
7. A storage medium characterized in that the storage medium stores a computer program configured to execute the continuous recording method according to any one of claims 1 to 6.
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