CN113176608B - DAS six-component seismic signal decoupling and recovery method of spirally wound optical fiber - Google Patents
DAS six-component seismic signal decoupling and recovery method of spirally wound optical fiber Download PDFInfo
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Abstract
The invention provides a decoupling and recovery method of six-component seismic signals of DAS (distributed optical system) of a spirally-wound optical fiber, belonging to the technical field of geophysical exploration, and the decoupling and recovery method of the six-component seismic signals of DAS of the spirally-wound optical fiber comprises the steps of S1, spirally winding optical fibers facing to multi-component vibration signals on the same cylinder; s2, acquiring seismic data by the spirally wound optical fiber; s3, determining a coordinate mapping relation between the multi-component wound optical fiber signal and the original vibration signal; s4, decoupling and recovering a real seismic wave vibration signal; and S5, verifying the error of the real seismic wave vibration signal, and according to the vibration sensitivity range of the spirally wound optical fiber, decoupling and recovering the six-component signals from the spirally wound optical fiber signal to the real seismic wave vibration at the position of the optical fiber by using the coordinate mapping relation between the spirally wound optical fiber and the vibration signal, so that more reasonable and reliable six-component seismic wave information is obtained, and the development of the DAS in the fine oil-gas seismic exploration can be promoted.
Description
Technical Field
The invention belongs to the technical field of geophysical exploration, and particularly relates to a DAS six-component seismic signal decoupling and recovery method of a spirally wound optical fiber.
Background
Distributed Acoustic Sensing (DAS) is a novel continuous, Distributed, real-time fiber Sensing technology based on fiber rayleigh backscattering. DAS uses optical fiber as the front end of the system, and acquires seismic data in real time by inverting the relative change of Rayleigh backscattering interference signals at various positions in the optical fiber at different moments.
However, the DAS directly measures the phase change of two points of rayleigh backscattered light in the optical fiber, which is mainly caused by the stretching and compressing of the optical fiber in the axial direction, so that the straight optical fiber can only measure the signal component along the axial direction of the optical fiber, but cannot detect the signal components in other directions (i.e. the "single component" problem), and it is difficult to meet the requirement of the fine oil and gas seismic exploration for multi-component information. Currently, there are two methods for implementing a multi-component DAS, one is to implement detection of radial vibration signals by simultaneously measuring intensity information and polarization information of scattered light in an optical fiber (woliffski, 1999), and the other is to change the physical shape of the optical fiber, such as a spiral winding. The spiral winding optical fiber is formed by winding a straight optical fiber on a cylinder with a specific diameter at a specific angle, so that the optical fiber has relatively sensitive angles to vibration in different directions, and the range of seismic waves detected by the DAS is effectively enlarged. DAS signals acquired by spirally wound optical fibers not only contain vibration information in the vertical direction, but also contain vibration information in the horizontal direction, namely multi-component seismic wave information, however, signals acquired after the optical fibers are wound cannot directly represent real seismic wave vibration signals at the positions of the optical fibers. How to decouple the real strain caused by seismic wave vibration at the position of the optical fiber according to the optical fiber winding mode has important guiding significance for recovering multi-component seismic information and promoting the application of DAS in fine oil-gas seismic exploration.
Disclosure of Invention
The embodiment of the invention provides a DAS six-component seismic signal decoupling and recovery method for spirally winding an optical fiber, and aims to solve the problem that a signal obtained after the existing optical fiber is wound cannot directly represent a real seismic wave vibration signal at the position of the optical fiber.
In view of the above problems, the technical solution proposed by the present invention is:
a DAS six-component seismic signal decoupling and recovery method of spirally wound optical fibers comprises the following steps:
s1, spirally winding the optical fibers facing the multi-component vibration signals on the same cylinder;
s2, collecting seismic data by spirally winding the optical fiber;
s3, determining a coordinate mapping relation between the multi-component wound optical fiber signal and the original vibration signal;
s4, decoupling and recovering a real seismic wave vibration signal;
and S5, verifying the true seismic wave vibration signal error.
As a preferred technical solution of the present invention, the step S1 specifically includes:
s11, defining the axial direction of the spiral winding axis of the optical fiber as the z-axis direction, the radial directions as the x and y directions, respectively, determining the positive winding direction according to the right hand rule, defining the included angle between the tangent line of the optical fiber and the O-xy plane as the spiral angle of the optical fiber, the angle is alpha 1 、α 2 、α 3 ……α N ；
And S12, uniformly winding the N optical fibers from the same point in the axial direction according to the corresponding angles in the negative direction.
As a preferred technical solution in the present invention, the step S2 specifically includes:
s21, dividing the laser pulse signal into N paths through different power dividers and couplers, and respectively injecting the N paths of laser pulse signal into N optical fibers synchronously;
s22, each optical fiber is equivalent to a DAS component system to carry out independent detection, Rayleigh backscattering signals transmitted back from each point of the optical fiber in a reverse direction are received, heterodyne detection is carried out on the scattering signals, demodulation is carried out according to a digital coherence algorithm, and finally the change relation of the strain at the position along with time is obtained, wherein the change relation of the strain along with time reflects real seismic wave vibration signals.
As a preferred technical solution in the present invention, the step S3 specifically includes:
s31, defining the direction of the optical fiber spiral winding axis as the z-axis direction of the global coordinate system, and keeping the positive direction consistent with the positive direction when the optical fiber is wound;
s32, there is a local coordinate system O-m at each point S along the fiber x l z n y Defining the forward tangent direction of each point of the spirally wound optical fiber as a local coordinate system m of the point x The positive direction of the axis;
s33, defining the local coordinate system at the starting point as the initial local coordinate system, and m thereof x 、l z 、n y The axes are respectively parallel to the x, y and z axes of the global coordinate system, and no included angle exists between the corresponding coordinate axes;
s34, for any point S on the ith optical fiber, the transformation relation between the local coordinate system and the global coordinate system is as follows:
the initial local coordinate system is firstly rotated clockwise by theta around the z-axis from the initial position of the optical fiber si Coinciding with the origin of the S point local coordinate system, and then rotating alpha counterclockwise around the y axis i The angle is superposed with each coordinate axis of the S point local coordinate system, and a mathematical relation of a coordinate transformation process is established according to a coordinate rotation theory;
wherein, theta si The ith optical fiber is rotated by an angle alpha from the initial point to the point S i Is the ith fiber helix angle.
As a preferred technical solution in the present invention, the mathematical relationship of the coordinate transformation process established in step S34 is a coordinate mapping relationship between each point of the ith wound optical fiber and the global coordinate system O-xyz, and its expression formula is as follows:
as a preferred technical solution in the present invention, the step S4 specifically includes: after the coordinate mapping relationship is obtained in step S34, in the case of using N optical fiber combinations with different helix angles, the average value m of the seismic wave vibration strain of each point on each optical fiber on the same height plane in the global coordinate system is obtained by using least squares, and the expression formula is as follows:
in the formula: m is the average value of the seismic wave vibration strain of each point on each optical fiber on the same height plane;
d N axial strain of the Nth optical fiber under a local coordinate system;
λ is a regularization parameter, wherein λ > 0;
i is an identity matrix;
g is a matrix.
As a preferred embodiment of the present invention, the matrix G is constructed according to ∈' ═ R ∈ RT, where ∈ is a dependent variable ∈ in a global coordinate system xx 、ε yy 、ε zz 、ε xy 、ε xz 、ε yz And ε' is the dependent variable ε of local coordinate system mm 、ε ll 、ε nn 、ε ml 、ε mn 、ε ln The specific construction mode is that the same elements in the matrix at two ends with equal sign of epsilon' ═ R epsilon RT are correspondingly equal according to epsilon mm And epsilon xx 、ε yy 、ε zz 、ε xy 、ε xz 、ε yz The mapping relational expression between the optical fiber measuring signal under the local coordinate system and the strain caused by the seismic wave vibration under the global coordinate system is obtained.
As a preferred technical solution in the present invention, an expression of a mapping relation between the fiber measurement signal in the local coordinate system and the strain caused by the seismic wave vibration in the global coordinate system is as follows:
in the formula: epsilon mm The fiber axial strain in a local coordinate system;
As a preferred technical solution in the present invention, the step S5 specifically includes: comparing true and decoupling recovered strain signals, wherein the wave crest and the wave trough of the strain signals are matched with each other in time-space position relation and wavelength frequency, so that the kinematic characteristics and the dynamic characteristics of the strain signals are consistent, the decoupling recovered seismic wave signals are equivalent to the true seismic wave signals in terms of both amplitude characteristics and phase characteristics, the error is estimated, and when the result shows that the error is less than or equal to 3%, the decoupling recovery of the true seismic wave signals in the error range can be realized.
As a preferred technical solution of the present invention, the expression of the estimation error is as follows:
compared with the prior art, the invention has the beneficial effects that: according to the vibration sensitivity range of the spirally wound optical fiber, decoupling recovery from the spirally wound optical fiber signal to the actual seismic wave vibration six-component signal at the position of the optical fiber is realized by utilizing the coordinate mapping relation between the spirally wound optical fiber and the vibration signal, so that more reasonable and reliable six-component seismic wave information is obtained, and the development of DAS in fine oil-gas seismic exploration can be promoted.
The above description is only an overview of the technical solutions of the present invention, and the present invention can be implemented in accordance with the content of the description so as to make the technical means of the present invention more clearly understood, and the above and other objects, features, and advantages of the present invention will be more clearly understood.
Drawings
FIG. 1 is a schematic flow chart of a DAS six-component seismic signal decoupling and recovery method for helically wound optical fibers disclosed in the present invention;
FIG. 2 is a schematic diagram of six optical fiber windings for a DAS six-component seismic signal decoupling and recovery method for helically wound optical fibers in accordance with the present disclosure;
FIG. 3 is a DAS spiral-wound optical fiber coordinate system transformation flow chart of the DAS six-component seismic signal decoupling and recovery method for spiral-wound optical fibers disclosed by the invention;
FIG. 4 is a schematic diagram of signals acquired after six optical fibers are spirally wound according to the DAS six-component seismic signal decoupling and recovery method for spirally wound optical fibers disclosed by the invention;
FIG. 5 is a schematic diagram of the true strain produced by the seismic waves of the DAS six-component seismic signal decoupling and recovery method of the disclosed helically wound optical fiber;
FIG. 6a is a schematic diagram of the decoupling recovery result of six helically wound fibers of the DAS six-component seismic signal decoupling and recovery method of helically wound fibers disclosed in the present invention;
FIG. 6b is a schematic error diagram of the decoupling recovery results of six helically wound fibers and the real seismic signals according to the method for decoupling and recovering six-component seismic signals of DAS using helically wound fibers of the present invention;
FIG. 7 is a schematic diagram of a single trace comparison between a DAS six-component seismic signal decoupling and recovery method of the disclosed helically wound optical fiber and real seismic signals.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present invention more apparent, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. It is to be understood that the embodiments described are only some of the embodiments of the present invention, and not all of them. All other embodiments, which can be obtained by a person skilled in the art without inventive efforts based on the embodiments of the present invention, are within the scope of protection of the present invention.
Thus, the following detailed description of the embodiments of the present invention, presented in the figures, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. All other embodiments, which can be obtained by a person skilled in the art without any inventive step based on the embodiments of the present invention, are within the scope of the present invention.
It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, it need not be further defined or explained in subsequent figures.
In the description of the present invention, it is to be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", and the like, indicate orientations or positional relationships based on those shown in the drawings, merely for convenience of description and simplicity of description, and do not indicate or imply that the device or element so referred to must have a particular orientation, be constructed in a particular orientation, and be operated, and thus, are not to be construed as limiting the present invention.
Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or to implicitly indicate the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present invention, "a plurality" means two or more unless specifically defined otherwise.
Examples
Referring to the attached figure 1, the invention provides a technical scheme: a DAS six-component seismic signal decoupling and recovery method of a spirally wound optical fiber comprises the following steps:
s1, the optical fiber facing the multi-component vibration signal is spirally wound on the same cylinder.
In this embodiment, referring to fig. 2, step S1 specifically includes:
s11, defining the axial direction of the optical fiber spiral winding shaft as the z-axis direction, the radial directions as the x and y directions respectively, determining the winding positive direction according to the right-hand rule, defining the included angle between the optical fiber tangent line and the O-xy plane as the optical fiber helical angle, the angle is alpha 1 、α 2 、α 3 ……α N 。
And S12, uniformly winding the N optical fibers from the same point in the axial direction according to the corresponding angles in the negative direction.
Specifically, the N optical fibers start from the same point and are uniformly wound in the negative direction along the axial direction according to corresponding angles, different optical fiber helical angles can influence the uniform distribution of helical angles in the winding process of the optical fibers in the sensitive range of the incident angle of seismic waves, and the axial and radial vibration information can be acquired more completely.
Optionally, a polyethylene interlayer is added between every two optical fibers in the inner layer and filled with fiber paste, so that the optical fibers are in different layers and the coupling between the optical fibers and the cylinder is ensured; the outer layer package comprises a steel wire reinforcement, a PE inner sheath, a steel-polyethylene shield and a PVC outer sheath, so that the optical cable has good mechanical property and strong environment adaptability.
It should be noted that the spiral wound optical fiber is a standard single mode optical fiber, and the manufacturing process can be implemented with reference to the existing standard "single mode communication outdoor optical cable for pipeline, direct-buried and non-self-supporting aerial laying GB/T29233-.
S2, acquiring the seismic data by the spiral wound optical fiber.
In this embodiment, step S2 specifically includes:
and S21, dividing the laser pulse signal into N paths through different power dividers and couplers, and respectively and synchronously injecting the N paths of laser pulse signals into N optical fibers.
S22, each optical fiber is equivalent to a DAS component system to carry out independent detection, Rayleigh backscattering signals transmitted back by each point of the optical fiber in a reverse direction are received, heterodyne detection is carried out on the scattering signals, demodulation is carried out according to a digital coherent algorithm, and finally the change relation of the strain at the position along with time is obtained, wherein the change relation of the strain along with time reflects the strain caused by seismic wave vibration.
In the above embodiment, in further practical application, when the wound optical fibers are used for data acquisition, the entire sensing structure utilizes N optical fibers, and the N optical fibers share the same high-coherence laser signal source and the acousto-optic modulator during the acquisition process.
And S3, determining the coordinate mapping relation between the multi-component wound optical fiber signal and the original vibration signal.
In this embodiment, referring to fig. 3 to 4, step S3 specifically includes:
and S31, defining the direction of the optical fiber spiral winding axis as the z-axis direction of the global coordinate system, and keeping the positive direction consistent with the positive direction when the optical fiber is wound.
S32, a local coordinate system O-m exists at each point S along the fiber x l z n y Defining the forward tangent direction of each point of the spirally wound optical fiber as a local coordinate system m of the point x The positive direction of the axis.
S33, defining the local coordinate system at the starting point as the initial local coordinate system, wherein m is x 、l z 、n y The axes are respectively parallel to the x, y and z axes of the global coordinate system, and no included angle exists between the corresponding coordinate axes.
S34, regarding any point S on the ith optical fiber, the transformation relationship between the local coordinate system and the global coordinate system is:
the initial local coordinate system is firstly rotated clockwise by theta around the z-axis from the initial position of the optical fiber si Coinciding with the origin of the local coordinate system of the point S and then rotating alpha counterclockwise around the y axis i The angle is superposed with each coordinate axis of the S point local coordinate system, and a mathematical relation of a coordinate transformation process is established according to a coordinate rotation theory;
wherein, theta si The ith optical fiber is rotated by an angle alpha from the initial point to the point S i Is the ith fiber helix angle.
Further, the mathematical relationship of the coordinate transformation process established in step S34 is the coordinate mapping relationship between each point of the ith wound optical fiber and the global coordinate system O-xyz, and the expression formula is as follows:
and S4, decoupling and recovering the real seismic wave vibration signals.
In this embodiment, step S4 specifically includes: after obtaining the coordinate mapping relationship through step S34, in the case of adopting N optical fiber combinations with different helix angles, it adopts least squares to solve the average value m of the strain caused by seismic wave vibration in the global coordinate system, and its expression formula is as follows:
in the formula: m is the average value of the strain caused by the vibration of the seismic waves of each point on each optical fiber on the same height plane;
d N axial strain of the Nth optical fiber under a local coordinate system;
λ is a regularization parameter, wherein λ > 0;
i is an identity matrix;
g is a matrix.
In particular, the matrix G is based on ∈' ═ R ∈ R T Is constructed, wherein epsilon is a dependent variable epsilon under a global coordinate system xx 、ε yy 、ε zz 、ε xy 、ε xz 、ε yz And ε' is the local coordinate system strain ε mm 、ε ll 、ε nn 、ε ml 、ε mn 、ε ln The specific construction mode is that epsilon' ═ R epsilon R T The same elements in the equal-sign two-end matrix are correspondingly equal according to epsilon mm And epsilon xx 、ε yy 、ε zz 、ε xy 、ε xz 、ε yz The mapping relation between the optical fiber measuring signal under the local coordinate system and the strain caused by the seismic wave vibration under the global coordinate system is obtained.
Further, the expression of the mapping relation between the fiber measurement signal in the local coordinate system and the strain caused by the seismic wave vibration in the global coordinate system is as follows:
in the formula: epsilon mm Is the fiber axial strain in the local coordinate system;
And S5, verifying the error of the real seismic wave vibration signal.
In this embodiment, step S5 specifically includes: comparing true and decoupling recovered strain signals, wherein the wave crest and the wave trough of the strain signals are matched with each other in time-space position relation and wavelength frequency, so that the kinematic characteristics and the dynamic characteristics of the strain signals are consistent, the decoupling recovered seismic wave signals are equivalent to the true seismic wave signals in terms of both amplitude characteristics and phase characteristics, the error is estimated, and when the result shows that the error is less than or equal to 3%, the decoupling recovery of the true seismic wave signals in the error range can be realized.
Specifically, the expression of the estimation error is as follows:
alternatively, the error is verified experimentally using borehole seismic data, taking six helically wound fibers as an example. Referring to fig. 4, six helically wound optical fiber DAS signals with helical angles of 25 °, 30 °, 40 °, 50 °, 60 °, and 65 °, respectively, are set to a model depth of 100m for 0.15 s; referring to FIG. 5, the true strain due to seismic waves in a well is shown; referring to fig. 6a and 6b, it is the strain result caused by the original seismic wave vibration recovered by the spirally wound optical fiber with six spiral angles of 25 °, 30 °, 40 °, 50 °, 60 ° and 65 °, respectively; referring to fig. 7, it shows the result of comparing the single-channel signal between the recovery result by using six optical fibers and the strain caused by the vibration of the original seismic wave.
One or more technical solutions in the embodiments of the present application have at least one or more of the following technical effects:
according to the vibration sensitivity range of the spirally wound optical fiber, decoupling recovery from the spirally wound optical fiber signal to the actual seismic wave vibration six-component signal at the position of the optical fiber is realized by utilizing the coordinate mapping relation between the spirally wound optical fiber and the vibration signal, so that more reasonable and reliable seismic wave information of six components is obtained, and the development of DAS in fine oil-gas seismic exploration can be promoted.
The above description is only a preferred embodiment of the present invention, and is not intended to limit the present invention, and various modifications and changes may be made to the present invention by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.
Claims (8)
1. A DAS six-component seismic signal decoupling and recovery method of a spirally wound optical fiber is characterized by comprising the following steps:
s1, spirally winding the optical fibers facing the multi-component vibration signals on the same cylinder;
s2, acquiring seismic data by the spirally wound optical fiber;
s3, determining a coordinate mapping relation between the multi-component wound optical fiber signal and the original vibration signal;
the step S3 specifically includes:
s31, defining the direction of the optical fiber spiral winding axis as the z-axis direction of the global coordinate system, and keeping the positive direction consistent with the positive direction when the optical fiber is wound;
s32, a local coordinate system O-m exists at each point S along the fiber x l z n y Defining the forward tangent direction of each point of the spirally wound optical fiber as a local coordinate system m of the point x The positive direction of the axis;
s33, defining the local coordinate system at the starting point as the initial local coordinate system, and m thereof x 、l z 、n y The axes are respectively parallel to the x, y and z axes of the global coordinate system, and no included angle exists between the corresponding coordinate axes;
s34, regarding any point S on the ith optical fiber, the transformation relationship between the local coordinate system and the global coordinate system is:
the initial local coordinate system is firstly rotated clockwise by theta around the z-axis from the initial position of the optical fiber si Coinciding with the origin of the S point local coordinate system and then counterclockwise around the y axisNeedle rotation alpha i The angle is coincident with each coordinate axis of the S point local coordinate system, and a mathematical relation of a coordinate transformation process is established according to a coordinate rotation theory;
wherein, theta si The rotation angle of the ith optical fiber from the initial point to the S point, alpha i Is the ith optical fiber helical angle;
s4, decoupling and recovering a real seismic wave vibration signal;
the step S4 specifically includes: after the coordinate mapping relationship is obtained in step S3, in the case of using N optical fiber combinations with different helix angles, the average value m of the strain caused by the vibration of the seismic wave of each point on each optical fiber on the same height plane in the global coordinate system is obtained by using the least square method, and the expression formula is as follows:
in the formula: m is the average value of the strain caused by the vibration of the seismic waves of each point on each optical fiber on the same height plane;
d N axial strain of the Nth optical fiber under a local coordinate system;
λ is a regularization parameter, wherein λ > 0;
i is an identity matrix;
g is a matrix;
and S5, verifying the error of the real seismic wave vibration signal.
2. The method for decoupling and recovering six-component seismic signals of DAS using helically wound optical fiber according to claim 1, wherein the step S1 specifically includes:
s11, defining the axial direction of the optical fiber spiral winding shaft as the z-axis direction, the radial directions as the x and y directions respectively, determining the positive winding direction according to the right-hand rule, and defining lightThe included angles between the tangent line and the O-xy plane are the fiber helix angles, which are respectively alpha 1 、α 2 、α 3 ……α N ；
And S12, uniformly winding the N optical fibers from the same point in the axial direction according to the corresponding angles in the negative direction.
3. The method for DAS six-component seismic signal decoupling and recovery of claim 1, wherein the step S2 specifically comprises:
s21, dividing the laser pulse signal into N paths through different power dividers and couplers, and respectively and synchronously injecting the N paths into N optical fibers;
s22, each optical fiber is equivalent to a DAS component system to carry out independent detection, Rayleigh backscattering signals transmitted back from each point of the optical fiber in a reverse direction are received, heterodyne detection is carried out on the scattering signals, demodulation is carried out according to a digital coherence algorithm, and finally the change relation of the strain at the position along with time is obtained, wherein the change relation of the strain along with time reflects real seismic wave vibration signals.
4. The method for decoupling and recovering a DAS six-component seismic signal of claim 1, wherein the mathematical relationship of the coordinate transformation process established in step S34 is a coordinate mapping relationship between each point of the ith wound fiber and a global coordinate system O-xyz, and the expression formula is as follows:
5. the method of claim 1 for DAS six-component seismic signal decoupling and recovery in which matrix G is based on ε' ═ R ε R T Is constructed, wherein epsilon is a dependent variable epsilon under a global coordinate system xx 、ε yy 、ε zz 、ε xy 、ε xz 、ε yz Epsilon' is a dependent variable of a local coordinate systemε mm 、ε ll 、ε nn 、ε ml 、ε mn 、ε ln The concrete construction mode is that epsilon' ═ R epsilon R T The same elements in the matrixes at the two ends of the equal sign are correspondingly equal according to the epsilon mm And e xx 、ε yy 、ε zz 、ε xy 、ε xz 、ε yz The mapping relation between the optical fiber measuring signal under the local coordinate system and the strain caused by the seismic wave vibration under the global coordinate system is obtained.
6. The method for DAS six-component seismic signal decoupling and recovery in accordance with claim 5, wherein the expression of the mapping relation between the fiber measurement signal in the local coordinate system and the strain caused by seismic wave vibration in the global coordinate system is as follows:
in the formula: epsilon mm Is the fiber axial strain in the local coordinate system;
7. The method for DAS six-component seismic signal decoupling and recovery of claim 1, wherein the step S5 specifically comprises: comparing the true strain signals with the decoupling recovery strain signals, when the wave crests and the wave troughs of the strain signals are matched with the wave troughs in time-space position and wavelength frequency, showing that the kinematic characteristics and the dynamic characteristics of the strain signals are consistent, the decoupling recovery seismic wave signals are equal to the true seismic wave signals in terms of amplitude characteristics and phase characteristics, estimating errors, and when the result shows that the errors are less than or equal to 3%, realizing the decoupling recovery of the true seismic wave signals in an error range.
8. The method of DAS six-component seismic signal decoupling and recovery according to claim 7, wherein the estimation error is expressed as follows:
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Application publication date: 20210727 Assignee: Dongying Changying Petroleum Technology Co.,Ltd. Assignor: CHINA University OF PETROLEUM (EAST CHINA) Contract record no.: X2024980005629 Denomination of invention: Decoupling and Restoration Method of DAS Six Component Seismic Signal for Spiral Wound Fiber Optics Granted publication date: 20220726 License type: Common License Record date: 20240511 |