CN-122017952-A - Distributed acoustic sensing dragging type seismic exploration optical cable system and method

CN122017952ACN 122017952 ACN122017952 ACN 122017952ACN-122017952-A

Abstract

The invention belongs to the technical field of seismic exploration, and particularly relates to a distributed acoustic sensing dragging type seismic exploration optical cable system and method. According to the invention, through the acquisition of the dragging data and the correction of the track of the optical cable, the actual position of the optical cable along the ground surface can be accurately measured, a reliable space reference is provided for high-precision seismic exploration, the distribution state and the sampling strategy of the optical cable can be dynamically adjusted in the dragging process, the dragging speed, the posture change and the application deviation are compensated, so that the acquisition of acoustic signals is more stable and reliable, the optical cable can respond to seismic waves in real time by applying seismic excitation to an excitation section and combining strain information, the high-precision seismic response acquisition along the length direction of the optical cable is realized, the dragging data, the posture and the strain compensation strategy are introduced, errors caused by uneven dragging movement and sampling intervals are eliminated, the precision and the detection reliability of the acoustic signals are improved, and the generated seismic exploration result not only comprises a seismic wave propagation path and wave amplitude distribution, but also can identify potential abnormal areas.

Inventors

LIU HAO
ZHOU LIXIN
JIANG XIAODONG

Assignees

江苏斯特利通信科技有限公司

Dates

Publication Date: 20260512
Application Date: 20260122

Claims (10)

1. A distributed acoustic sensing towed seismic acquisition cable method, comprising: acquiring the dragging data corresponding to the distributed acoustic sensing optical cable in the dragging process; Acquiring actual moving tracks of a plurality of sampling positions of the distributed acoustic sensing optical cable along the length direction of the optical cable in the dragging process, and acquiring the earth surface sampling coordinates of each sampling position based on the actual moving tracks; Acquiring a set state according to the dragging data, acquiring an excitation section for applying seismic excitation based on the set state, applying the seismic excitation to a region to be detected based on the excitation section, and acquiring strain information of a plurality of sampling positions along the length direction of the optical cable based on the seismic excitation; Acquiring an application position coordinate for applying seismic excitation, and acquiring a sampling adjustment strategy by combining an actual moving track; acquiring an acoustic response signal set based on the length direction of the optical cable and a sampling adjustment strategy; based on the ground surface sampling coordinates, and combining the drag data and the strain information to compensate the acoustic response signal set, so as to obtain an acoustic compensation signal set; and generating a seismic detection result according to the acoustic compensation signal set and combining the sampling positions.
2. The method for acquiring the drag data corresponding to the distributed acoustic sensing optical cable in the drag process according to claim 1, comprising: the distributed acoustic sensing optical cable is distributed on the ground surface of the area to be detected in a dragging mode; In the process of dragging and laying, judging whether the ground surface contact state meets the dragging condition according to the ground surface contact state of the distributed acoustic sensing optical cable at different dragging positions; If the ground surface contact state meets the dragging condition, acquiring dragging data corresponding to the distributed acoustic sensing optical cable, wherein the dragging data comprises dragging speed, dragging direction and optical cable gesture; and if the ground surface contact state does not meet the dragging condition, adjusting the ground surface contact state of the distributed acoustic sensing optical cable at different dragging positions so that the adjusted ground surface contact state meets the dragging condition.
3. The method of a distributed acoustic sensing towed seismic acquisition cable of claim 1, wherein acquiring actual movement trajectories of a plurality of sampling locations of the distributed acoustic sensing cable along a length of the cable during towing, acquiring surface sampling coordinates for each sampling location based on the actual movement trajectories, comprises: Acquiring actual movement tracks of a plurality of sampling positions of the distributed acoustic sensing optical cable along the length direction of the optical cable in the dragging process; Acquiring adjacent positions of a plurality of sampling positions in the length direction of the optical cable, and acquiring displacement change ranges at adjacent dragging moments based on the adjacent positions; judging whether the actual moving track exceeds the displacement change range; if the actual moving track exceeds the displacement change range, acquiring the moving track exceeding range, correcting the actual moving track according to the moving track exceeding range, and acquiring the surface sampling coordinates corresponding to each sampling position in the area to be detected based on the corrected actual moving track; and if the actual moving track does not exceed the displacement change range, acquiring the corresponding earth surface sampling coordinates of each sampling position in the region to be detected based on the actual moving track.
4. The distributed acoustic sensing drag-type seismic acquisition cable method of claim 1, wherein acquiring set state information from drag data and acquiring an excitation section for applying seismic excitation based on the set state information, applying seismic excitation to an area to be detected based on the excitation section, comprises: extracting the dragging speed, the dragging direction and the optical cable gesture based on the dragging data, and acquiring initial position information, speed information and gesture information corresponding to each sampling position along the length direction of the optical cable; acquiring a displacement range and a direction of each sampling position based on the initial position information, the speed information and the dragging direction; Acquiring the gesture change range of each sampling position based on gesture information and the dragging direction; integrating the displacement range, the direction and the gesture change range of each sampling position to form set state information; Selecting an excitation section which accords with the application of seismic excitation according to the set state information; applying seismic excitation to the region to be detected based on the excitation section, so that seismic waves act on the distributed acoustic sensing optical cable; strain information is acquired at a plurality of sampling locations along the length of the fiber optic cable based on the seismic excitation.
5. The method of distributed acoustic sensing towed seismic acquisition cable of claim 1, wherein acquiring the application location coordinates of an applied seismic stimulus and acquiring a sample adjustment strategy in combination with an actual movement trajectory includes: acquiring application position coordinates for applying seismic excitation; acquiring an application distance deviation according to the application position coordinates and combining the actual movement track; Acquiring a preset sampling table, wherein the preset sampling table comprises a plurality of application distance deviation intervals and sampling adjustment strategies corresponding to each application distance deviation; And acquiring a corresponding sampling adjustment strategy from a preset sampling table according to an application distance deviation interval corresponding to the application distance deviation.
6. The distributed acoustic sensing towed seismic acquisition cable method of claim 1, wherein acquiring a set of acoustic response signals based on a cable length direction and a sampling adjustment strategy, comprises: acquiring an acoustic initial signal acquired by a distributed acoustic sensing optical cable after seismic excitation is applied; correcting the acoustic initial signal based on a sampling adjustment strategy; and arranging the corrected acoustic initial signals according to the length direction of the optical cable to obtain an acoustic response signal set.
7. The distributed acoustic sensing drag type seismic exploration optical cable method according to claim 1, based on earth surface sampling coordinates, and compensating an acoustic response signal set by combining drag data and strain information, to obtain an acoustic compensation signal set, comprising: converting the set of acoustic response signals into a set of acoustic response signals represented in geospatial coordinates based on the surface sampling coordinates; Extracting a dragging speed and an optical cable posture based on the dragging data, and acquiring a corresponding correction value according to the dragging speed and the optical cable posture; acquiring a strain reference value and acquiring strain deviation based on strain information; Acquiring a compensation strategy according to the correction value and the strain deviation; And compensating the corresponding acoustic response signals in the acoustic response signal set based on a compensation strategy, and summarizing to obtain the acoustic compensation signal set.
8. The distributed acoustic sensing towed seismic acquisition cable method of claim 1, wherein generating a seismic acquisition from a set of acoustic compensation signals in combination with sampling locations, comprising: acquiring acoustic signal distribution according to the acoustic compensation signal set and the corresponding sampling position; Acquiring seismic response information corresponding to the sampling position based on acoustic signal distribution, wherein the seismic response information comprises amplitude variation, phase variation and wave propagation state; and generating a seismic detection result of the region to be detected according to the seismic response information and the earth surface sampling coordinates of the sampling position, wherein the seismic detection result comprises a seismic wave propagation path, amplitude distribution and potential abnormal region information.
9. A distributed acoustic sensing towed seismic acquisition cable system for use in the distributed acoustic sensing towed seismic acquisition cable method of any of claims 1 through 8, comprising: The dragging acquisition module is used for acquiring dragging data corresponding to the distributed acoustic sensing optical cable in the dragging process; The sampling position module is used for acquiring actual movement tracks of a plurality of sampling positions of the distributed acoustic sensing optical cable along the length direction of the optical cable in the dragging process, and acquiring the earth surface sampling coordinates of each sampling position based on the actual movement tracks; the earthquake excitation module is used for acquiring a set state according to the dragging data, acquiring an excitation section for applying earthquake excitation based on the set state, applying the earthquake excitation to a region to be detected based on the excitation section, and acquiring strain information of a plurality of sampling positions along the length direction of the optical cable based on the earthquake excitation; The sampling adjustment module is used for acquiring the application position coordinates for applying the seismic excitation and acquiring a sampling adjustment strategy by combining the actual moving track; The acoustic response module is used for acquiring an acoustic response signal set based on the length direction of the optical cable and a sampling adjustment strategy; the acoustic compensation module is used for compensating the acoustic response signal set based on the earth surface sampling coordinates and combining the drag data and the strain information to obtain an acoustic compensation signal set; and the seismic detection module is used for generating a seismic detection result according to the acoustic compensation signal set and combining the sampling positions.
10. A distributed acoustic sensing towed seismic acquisition cable terminal, comprising: one or more processors; a storage device having one or more programs stored thereon; The distributed acoustic sensing towed seismic acquisition cable method of any one of claims 1 to 8, when the one or more programs are executed by the one or more processors, causing the one or more processors to implement performance of the method.

Description

Distributed acoustic sensing dragging type seismic exploration optical cable system and method Technical Field The invention belongs to the technical field of seismic exploration, and particularly relates to a distributed acoustic sensing dragging type seismic exploration optical cable system and method. Background The distributed acoustic sensing technology (Distributed Acoustic Sensing, DAS) utilizes the optical fiber itself as a sensing medium, can realize continuous strain and vibration detection along the length direction of the optical fiber, and is widely applied to the fields of seismic monitoring, oil and gas pipeline monitoring, boundary safety and the like. Traditional DAS seismic exploration generally relies on fixedly-laid optical cables, the optical cable requires large construction amount and time cost in the installation process, and the optical cables are difficult to lay in complex terrains or large-area areas. In addition, the fixed layout of the fiber optic cable is difficult to adapt to the rapidly changing surface environment, and may result in discontinuous signal sampling or insufficient spatial positioning accuracy, thereby affecting accurate measurement of seismic wave propagation characteristics. In the prior art, a drag-type optical cable is arranged to reduce construction difficulty, but the drag-type optical cable has problems in practical application. The conditions of uneven speed, attitude change, poor contact with the ground surface and the like of the optical cable can occur in the towing and laying process, so that sampling position deviation is caused, the corresponding relation between an acoustic signal and the ground surface position is influenced, accurate control is lacking in an earthquake excitation application area, uniform and repeatable strain response of the optical cable in the excitation area is difficult to ensure, and the reliability of earthquake response data is influenced. Disclosure of Invention The invention aims to provide a distributed acoustic sensing drag type seismic exploration optical cable system and a distributed acoustic sensing drag type seismic exploration optical cable method, which can solve the problems of low precision, poor controllability and insufficient adaptability of drag and layout optical cables in seismic exploration application in the prior art. The technical scheme adopted by the invention is as follows: A distributed acoustic sensing towed seismic acquisition cable method comprising: acquiring the dragging data corresponding to the distributed acoustic sensing optical cable in the dragging process; Acquiring actual moving tracks of a plurality of sampling positions of the distributed acoustic sensing optical cable along the length direction of the optical cable in the dragging process, and acquiring the earth surface sampling coordinates of each sampling position based on the actual moving tracks; Acquiring a set state according to the dragging data, acquiring an excitation section for applying seismic excitation based on the set state, applying the seismic excitation to a region to be detected based on the excitation section, and acquiring strain information of a plurality of sampling positions along the length direction of the optical cable based on the seismic excitation; Acquiring an application position coordinate for applying seismic excitation, and acquiring a sampling adjustment strategy by combining an actual moving track; acquiring an acoustic response signal set based on the length direction of the optical cable and a sampling adjustment strategy; based on the ground surface sampling coordinates, and combining the drag data and the strain information to compensate the acoustic response signal set, so as to obtain an acoustic compensation signal set; and generating a seismic detection result according to the acoustic compensation signal set and combining the sampling positions. In a preferred scheme, acquiring the drag data corresponding to the distributed acoustic sensing optical cable in the drag process includes: the distributed acoustic sensing optical cable is distributed on the ground surface of the area to be detected in a dragging mode; In the process of dragging and laying, judging whether the ground surface contact state meets the dragging condition according to the ground surface contact state of the distributed acoustic sensing optical cable at different dragging positions; If the ground surface contact state meets the dragging condition, acquiring dragging data corresponding to the distributed acoustic sensing optical cable, wherein the dragging data comprises dragging speed, dragging direction and optical cable gesture; and if the ground surface contact state does not meet the dragging condition, adjusting the ground surface contact state of the distributed acoustic sensing optical cable at different dragging positions so that the adjusted ground surface contact state meets the dragging condition. In