CN109471170B - Seismic data processing method and device - Google Patents

Abstract

The embodiment of the invention discloses a seismic data processing method and a device, wherein the seismic data processing method comprises the following steps: when the acquisition azimuth angles of the first seismic data body and the second seismic data body after the seismic mutual equalization processing are different, performing double-azimuth acquisition footprint attenuation processing on the first seismic data body after the seismic mutual equalization processing, and performing double-azimuth acquisition footprint attenuation processing on the second seismic data body after the seismic mutual equalization processing; and performing AVO mutual equalization processing on the first seismic data body and the second seismic data body after the attenuation processing of the two-position acquisition footprint. The embodiment of the invention reduces or even eliminates the seismic difference caused by the influence of the acquisition azimuth angle, thereby applying the non-repetitive dual-azimuth acquisition seismic data to the dynamic monitoring of the oil reservoir.

Description

Seismic data processing method and device

Technical Field

Embodiments of the present invention relate to, but not limited to, seismic processing, and more particularly, to a method and apparatus for processing seismic data.

Background

Time-lapse seismic is an effective means for monitoring reservoir dynamics, and the geometric positions of detectors for acquiring seismic data at different periods are absolutely repeated in the early 80 s, so that people begin to process repeated three-dimensional data as time-lapse data in the 90 s (2003 yellow and Asahi). Under the limitation of the acquisition cost and the current situation of oil field acquisition, scholars at home and abroad (such as 2007 Lingyun, 2012 Guo Min, 2014 Yi, 2016 WangJun and the like) do a great deal of research work on non-repetitive time-lapse seismic reservoir monitoring, prove the feasibility of the application of the technology and provide a mutual equalization processing method for eliminating the inconsistency of the earthquake by surface element resetting, amplitude equalization, time correction, phase correction and frequency filtering, post-stack matching filtering and the like. However, the above non-repetitive time-lapse seismic research only aims at the difference of the trace spacing, the receiving line spacing and the offset of the acquisition and observation system (such as the early conventional three-dimensional earthquake and the high-density three-dimensional earthquake) existing in the two-phase seismic data, and generally requires that the seismic azimuth angle is basically consistent or has a deviation of a small angle after the observation consistency processing (such as 2012 guo, 2014 chen honor). Due to the influence of weak anisotropy of the formation, when the formation medium is a Transverse isotropic (HTI) medium with a Horizontal axis of symmetry, the seismic travel, Amplitude and Variation of Amplitude with Offset (AVO) gradient properties have the greatest difference between 0 ° and 90 ° observations (2009 wubi). The two-phase seismic data with different acquisition azimuths have obvious seismic differences (such as azimuth acquisition footprints, azimuth amplitude differences (AVAZ, Azimuth AVO) and the like) under the influence of the azimuths, so that the cases of applying the two-phase seismic data to oil reservoir monitoring are almost absent, and the application of the two-phase non-repetitive seismic data to oil reservoir dynamic monitoring is further restricted.

Disclosure of Invention

The embodiment of the invention provides a seismic data processing method and a seismic data processing device, which can reduce or even eliminate seismic difference caused by the influence of an acquisition azimuth angle, so that non-repetitive dual-azimuth acquisition seismic data are applied to oil reservoir dynamic monitoring.

The embodiment of the invention provides a seismic data processing method, which comprises the following steps:

when the acquisition azimuth angles of the first seismic data body and the second seismic data body after the seismic mutual equalization processing are different, performing double-azimuth acquisition footprint attenuation processing on the first seismic data body after the seismic mutual equalization processing, and performing double-azimuth acquisition footprint attenuation processing on the second seismic data body after the seismic mutual equalization processing;

and performing AVO mutual equalization processing on the first seismic data body and the second seismic data body after the attenuation processing of the two-position acquisition footprint.

In an embodiment of the present invention, the performing dual-azimuth acquisition footprint attenuation processing on the first seismic data volume after seismic mutual equalization processing includes:

performing high intelligent filtering technology LIFT noise attenuation processing on the first seismic data volume after the seismic mutual equalization processing;

and performing energy equalization processing on the first seismic data body after the LIFT noise attenuation processing, and taking the first seismic data body after the energy equalization processing as the first seismic data body after the dual-azimuth acquisition footprint attenuation processing.

In this embodiment of the present invention, the performing LIFT noise attenuation processing on the first seismic data volume after seismic cross-equalization processing includes:

separating a first effective signal and a first interference signal of first seismic data of a section perpendicular to an acquisition azimuth in the first seismic data volume after the seismic mutual equalization processing;

and extracting a second effective signal from the first interference signal, and taking the sum of the first effective signal and the second effective signal as the first seismic data volume after the LIFT noise attenuation processing.

In an embodiment of the present invention, the performing energy equalization processing on the first seismic data volume after LIFT noise attenuation processing includes:

performing time-varying automatic gain processing on the first seismic data volume after the LIFT noise attenuation processing;

taking the ratio of the first seismic data volume after the LIFT noise attenuation processing to the first seismic data volume after the time-varying automatic gain processing as a first scale factor;

carrying out low-frequency array filtering on the first scale factor to obtain a second scale factor;

taking a ratio of the second scaling factor and the first scaling factor as the third scaling factor;

performing median filtering processing on the third scale factor along a non-inline direction;

and taking the product of the first seismic data volume after the LIFT noise attenuation processing and the third scale factor after the median filtering processing as the first seismic data volume after the energy equalization processing.

In the embodiment of the present invention, the performing two-side acquisition footprint attenuation processing on the second seismic data volume after seismic mutual equalization processing includes:

performing high intelligent filtering technology LIFT noise attenuation processing on the second seismic data volume after the seismic mutual equalization processing;

and performing energy equalization processing on the second seismic data body after the LIFT noise attenuation processing, and taking the second seismic data body after the energy equalization processing as the second seismic data body after the dual-azimuth acquisition footprint attenuation processing.

In this embodiment of the present invention, the performing LIFT noise attenuation processing on the second seismic data volume after seismic mutual equalization processing includes:

separating a third effective signal and a second interference signal of second seismic data vertical to a section of the acquisition position in the second seismic data volume after the seismic mutual equalization processing;

and extracting a fourth effective signal from the second interference signal, and taking the sum of the third effective signal and the fourth effective signal as the second seismic data body after the LIFT noise attenuation processing.

In this embodiment of the present invention, the performing energy equalization processing on the second seismic data volume after the LIFT noise attenuation processing includes:

performing time-varying automatic gain processing on the second seismic data volume after the LIFT noise attenuation processing;

taking the ratio of the second seismic data volume after the LIFT noise attenuation processing and the second seismic data volume after the time-varying automatic gain processing as a fourth scale factor;

carrying out low-frequency array filtering on the fourth scale factor to obtain a fifth scale factor;

taking a ratio of the fifth scaling factor and the fourth scaling factor as the sixth scaling factor;

performing median filtering processing on the sixth scale factor along a non-inline direction;

and taking the product of the second seismic data volume after the LIFT noise attenuation processing and the sixth scale factor after the median filtering processing as the second seismic data volume after the energy equalization processing.

In the embodiment of the present invention, the performing pre-stack dual-orientation AVO mutual equalization processing on the first seismic data volume and the second seismic data volume after the dual-orientation acquisition footprint attenuation processing includes:

respectively acquiring third seismic data of a preset area in the first seismic data body after the dual-azimuth acquisition footprint attenuation processing and fourth seismic data of the preset area in the second seismic data body after the dual-azimuth acquisition footprint attenuation processing;

determining a first relationship between a first correction factor and an angle of incidence from the third seismic data and the fourth seismic data; according to a first relation between a first correction coefficient and an incidence angle, pre-stack double-azimuth AVO mutual equalization processing is carried out on the second seismic data body after the double-azimuth acquisition footprint attenuation processing;

or determining a second relationship between a second correction factor and an angle of incidence from the third seismic data and the fourth seismic data; and performing pre-stack double-azimuth AVO mutual equalization processing on the first seismic data body subjected to the double-azimuth acquisition footprint attenuation processing according to a second relation between a second correction coefficient and an incidence angle.

In an embodiment of the invention, the determining a first relationship between the first correction factor and the angle of incidence from the third seismic data and the fourth seismic data comprises:

calculating a first ratio between the third seismic data and the fourth seismic data corresponding to the same incidence angle; fitting a first relation between the first correction coefficient and an incident angle according to the first ratio and the corresponding incident angle;

alternatively, the determining a second relationship between a second correction coefficient and an angle of incidence from the third seismic data and the fourth seismic data comprises:

calculating a second ratio between the fourth seismic data and the third seismic data corresponding to the same incidence angle; and fitting a second relation between the second correction coefficient and the incidence angle according to the second ratio and the corresponding incidence angle.

In an embodiment of the present invention, the performing pre-stack dual-orientation AVO mutual equalization processing on the second seismic data volume after the dual-orientation acquisition footprint attenuation processing according to the first relationship between the first correction coefficient and the incident angle includes:

multiplying each fifth seismic data in the second seismic data volume after the dual-azimuth acquisition footprint attenuation processing by a first correction coefficient corresponding to the incidence angle of the fifth seismic data in the first relation;

or, the pre-stack bi-azimuth AVO mutual equalization processing of the first seismic data volume after the two-azimuth acquisition footprint attenuation processing according to the second relationship between the second correction coefficient and the incident angle includes:

multiplying each sixth seismic data in the first seismic data volume after the dual-azimuth acquisition footprint attenuation processing by a second correction coefficient corresponding to the incidence angle of the sixth seismic data in the second relation.

In an embodiment of the present invention, the method further includes:

and carrying out oil reservoir monitoring according to the first seismic data body and the second seismic data body which are subjected to pre-stack double-azimuth AVO mutual equalization processing.

In the embodiment of the present invention, the method further includes:

and when the first seismic data body and the second seismic data body have differences of an observation system, performing surface element resetting, conventional seismic processing and seismic mutual equalization processing on the first seismic data body, and performing surface element resetting, conventional seismic processing and seismic mutual equalization processing on the second seismic data body.

In the embodiment of the present invention, the method further includes:

and when the first seismic data body and the second seismic data body have no difference of an observation system, performing conventional seismic processing and seismic mutual equalization processing on the first seismic data body, and performing conventional seismic processing and seismic mutual equalization processing on the second seismic data body.

The embodiment of the invention provides a seismic data processing device, which comprises:

the dual-azimuth acquisition footprint attenuation processing module is used for performing dual-azimuth acquisition footprint attenuation processing on the first seismic data body after seismic mutual equalization processing and performing dual-azimuth acquisition footprint attenuation processing on the second seismic data body after the seismic mutual equalization processing when the acquisition azimuth angles of the first seismic data body and the second seismic data body after the seismic mutual equalization processing are different;

and the AVO mutual equalization processing module is used for carrying out AVO mutual equalization processing on the first seismic data body and the second seismic data body after attenuation processing of the two side acquisition footprints.

The embodiment of the invention provides a seismic data processing device, which comprises a processor and a computer readable storage medium, wherein instructions are stored in the computer readable storage medium, and when the instructions are executed by the processor, any one of the seismic data processing methods is realized.

An embodiment of the invention proposes a computer-readable storage medium, on which a computer program is stored, which, when being executed by a processor, carries out the steps of any of the seismic data processing methods described above.

The embodiment of the invention comprises the following steps: when the acquisition azimuth angles of the first seismic data body and the second seismic data body after the seismic mutual equalization processing are different, performing double-azimuth acquisition footprint attenuation processing on the first seismic data body after the seismic mutual equalization processing, and performing double-azimuth acquisition footprint attenuation processing on the second seismic data body after the seismic mutual equalization processing; and performing pre-stack double-azimuth AVO mutual equalization processing on the first seismic data body and the second seismic data body after the attenuation processing of the double-azimuth acquisition footprint. According to the embodiment of the invention, the azimuth acquisition footprint influenced by the acquisition azimuth is reduced or even eliminated through the dual-azimuth acquisition footprint attenuation processing, and the AVAZ difference caused by the influence of the acquisition azimuth is reduced or even eliminated through the pre-stack dual-azimuth AVO mutual equalization processing, so that the seismic difference influenced by the acquisition azimuth is reduced or even eliminated, and the non-repetitive dual-azimuth acquisition seismic data is applied to the dynamic monitoring of the oil reservoir.

Additional features and advantages of embodiments of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of embodiments of the invention. The objectives and other advantages of the embodiments of the invention will be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.

Drawings

The accompanying drawings are included to provide a further understanding of the embodiments of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the examples of the invention serve to explain the principles of the embodiments of the invention and not to limit the embodiments of the invention.

FIG. 1 is a flow chart of a method of seismic data processing according to one embodiment of the present invention;

fig. 2 is a schematic structural diagram of a seismic data processing apparatus according to another embodiment of the present invention.

Detailed Description

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. It should be noted that the embodiments and features of the embodiments of the present invention may be arbitrarily combined with each other without conflict.

The steps illustrated in the flow charts of the figures may be performed in a computer system such as a set of computer-executable instructions. Also, while a logical order is shown in the flow diagrams, in some cases, the steps shown or described may be performed in an order different than here.

The related technology for non-repetitive time-lapse seismic processing comprises processing means such as surface element resetting, post-stack mutual homogenization processing, mutual equalization filtering and the like, can be used for matching processing of non-repetitive double-azimuth acquisition seismic, but cannot effectively weaken seismic response difference related to non-reservoir development brought by the difference of acquisition azimuths.

On the basis of conventional prestack mutual equalization processing, the relevant geostatistical acquisition footprint attenuation method roughly comprises the following steps: performing time-varying Automatic Gain Control (AGC) on the seismic data volume, and taking the ratio of the seismic data volume to the time-varying AGC seismic data volume as a first scale factor; smoothing the first scale factor in the direction of a seismic longitudinal survey line and the direction of a non-longitudinal survey line by adopting a three-dimensional geostatistical filtering method to obtain a second scale factor, and separating high-frequency interference which is influenced by uneven acquisition of a towing cable and is distributed in a strip shape in the first scale factor of energy; and multiplying the time-varying seismic data volume after AGC by a second scale factor to realize the acquisition footprint attenuation based on the geological statistics.

The earthquake acquisition footprint is a phenomenon of uneven energy distribution parallel to the longitudinal measuring line direction, the related geostatistical acquisition footprint attenuation method carries out time-varying automatic gain processing on an earthquake data body and carries out smoothing processing on a first scale factor in the earthquake longitudinal measuring line direction and a non-longitudinal measuring line direction at the same time, so that the fidelity of the energy in the longitudinal measuring line direction is damaged, and if single smoothing processing is carried out in the non-longitudinal measuring line direction, the interference of acquisition footprints with different magnitudes cannot be simultaneously attenuated, so that the phenomenon of fuzzy transverse acquisition footprints exists under the influence of the first scale factor and a sliding time window of geostatistical filtering, the requirement of double-azimuth time-shifting earthquake matching processing cannot be met, and the defects of poor amplitude retention and incapability of effectively removing the interference of the acquisition footprints with small magnitudes exist.

The azimuth amplitude difference of the seismic data acquired in a double azimuth mode has no effective solution.

Referring to fig. 1, an embodiment of the present invention provides a seismic data processing method, including:

step 100, when the acquisition azimuth angles of the first seismic data body and the second seismic data body after seismic mutual equalization processing are different, performing double-azimuth acquisition footprint attenuation processing on the first seismic data body after seismic mutual equalization processing, and performing double-azimuth acquisition footprint attenuation processing on the second seismic data body after seismic mutual equalization processing.

In the embodiment of the invention, when the acquisition azimuth angles of the first seismic data body and the second seismic data body after seismic mutual equalization processing are different, it is indicated that there is an acquisition azimuth difference between the first seismic data body and the second seismic data body, and the seismic data bodies have obvious seismic differences (such as azimuth acquisition footprint, azimuth amplitude difference and the like) due to the acquisition azimuth difference.

In the embodiment of the invention, the dual-azimuth acquisition footprint attenuation processing of the first seismic data volume after the seismic mutual equalization processing comprises the following steps:

performing high intelligence Filter Technology (LIFT) noise attenuation processing on the first seismic data volume after the seismic mutual equalization processing;

and performing energy equalization processing on the first seismic data body after the LIFT noise attenuation processing, and taking the first seismic data body after the energy equalization processing as the first seismic data body after the dual-azimuth acquisition footprint attenuation processing.

According to the embodiment of the invention, LIFT noise attenuation processing is adopted to remove the interference of the acquisition strips with small magnitude, and energy equalization processing is adopted to remove the phenomenon of energy nonuniformity with large magnitude and wide distribution, so that the azimuth acquisition footprint caused by the influence of the acquisition azimuth angle is reduced or even eliminated, and the non-repetitive dual-azimuth acquisition seismic data is applied to dynamic monitoring of the oil reservoir.

The LIFT noise reduction processing of the first seismic data body after the seismic mutual equalization processing comprises the following steps:

separating a first effective signal and a first interference signal of first seismic data of a section perpendicular to an acquisition azimuth in the first seismic data volume after the seismic mutual equalization processing; and extracting a second effective signal from the first interference signal, and taking the sum of the first effective signal and the second effective signal as a first seismic data volume after LIFT noise attenuation processing.

The single offset section can be extracted along the non-longitudinal line direction to obtain the section of the first seismic data body perpendicular to the acquisition direction after the seismic mutual equalization processing.

The separation of the first effective signal and the first interference signal of the first seismic data of the section perpendicular to the acquisition azimuth in the first seismic data volume after the seismic mutual equalization processing comprises the following steps:

converting the first seismic data of the time-space domain into first seismic data of a frequency-wavenumber domain;

filtering the first seismic data of the frequency-wavenumber domain by adopting a two-dimensional frequency-wavenumber domain inclined filtering function to obtain a first effective signal of the frequency-wavenumber domain and a first interference signal of the frequency-wavenumber domain;

the first effective signal of the frequency domain-wave number domain is converted into a first effective signal of a time-space domain, and the first interference signal of the frequency domain-wave number domain is converted into a first interference signal of the time-space domain.

Wherein formulas may be employed

The first seismic data in the time-space domain is converted into first seismic data in the frequency-wavenumber domain.

Wherein f is₁(t, x) is the first seismic data of the time-space domain, F₁And (f, k) is the first seismic data in the frequency-wavenumber domain.

Wherein the two-dimensional frequency-wavenumber domain slant filter function FK₁(DipL₁，DipH₁，FreqL₁，FreqH₁，KSM₁，FSM₁) Comprises the following steps:

wherein, DipL₁And DipH₁Defining a range of tilt time differences, DipL, of the first useful signal or the first interfering signal₁Is the minimum tilt time difference, DipH, of the first effective signal or the first interfering signal₁For the maximum tilt time difference of the first useful signal or the first interfering signal, the corresponding relation between the time-space domain and the frequency-wavenumber domain is

t is time, x is spatial position, k is wavenumber, f is frequency, D is time window range, FreqL₁Is the lowest cut-off frequency, FreqH, of the first useful signal or the first interfering signal₁Is the highest cut-off frequency, KSM, of the first useful signal or the first interfering signal₁A smoothing factor, FSM, in the wavenumber domain for the first useful signal or the first interfering signal₁A frequency domain smoothing factor, F, for the first desired signal or the first interfering signal₂And (f, k) is a first effective signal or a first interference signal in a frequency-wavenumber domain.

Wherein extracting the second effective signal from the first interference signal comprises:

converting the first interference signal of the time-space domain into a first interference signal of a frequency-wavenumber domain;

using low-frequency array filter functions F₂(FreqL₂，FreqH₂，Vel₁，Dx₁) Filtering the first interference signal in the frequency-wavenumber domain to obtain a second effective signal in the frequency-wavenumber domain;

and converting the second effective signal of the frequency-wave number domain into a second effective signal of a time-space domain.

Wherein, FreqL₂Is the lowest cut-off frequency, FreqH, of the second significant signal in the frequency-wavenumber domain₂Is the highest cut-off frequency, Vel, of the second significant signal in the frequency-wavenumber domain₁Is the wave velocity of the seismic waves, Dx₁Distance sampling for seismic trace space。

Wherein, the energy equalization processing of the first seismic data volume after the LIFT noise attenuation processing comprises the following steps:

performing time-varying automatic gain processing on the first seismic data volume after the LIFT noise attenuation processing;

taking the ratio of the first seismic data volume after the LIFT noise attenuation processing to the first seismic data volume after the time-varying automatic gain processing as a first scale factor;

carrying out low-frequency array filtering on the first scale factor to obtain a second scale factor; in particular, a low frequency array filter function F is used₂(FreqL₂，FreqH₂，Vel₁，Dx₁) Performing low-frequency array filtering on the first scale factor;

taking the ratio of the second scale factor to the first scale factor as the third scale factor, and performing median filtering processing on the third scale factor along the non-longitudinal line direction;

and taking the product of the first seismic data volume after the LIFT noise attenuation processing and the third scale factor after the median filtering processing as the first seismic data volume after the energy equalization processing.

The embodiment of the invention only carries out median filtering processing along the non-longitudinal measuring line direction to suppress uneven energy with larger magnitude and wide distribution, and does not carry out median filtering processing along the longitudinal measuring line direction, thereby not damaging the seismic energy along the longitudinal measuring line direction, ensuring the fidelity and the effectiveness of the seismic acquisition footprint attenuation, and simultaneously improving the accuracy of the acquisition footprint attenuation.

In the embodiment of the invention, the two-side acquisition footprint attenuation processing of the second seismic data volume after the seismic mutual equalization processing comprises the following steps:

performing LIFT noise attenuation processing on the second seismic data after the seismic mutual equalization processing;

and performing energy equalization processing on the second seismic data body after the LIFT noise attenuation processing, and taking the second seismic data body after the energy equalization processing as the second seismic data body after the dual-azimuth acquisition footprint attenuation processing.

Wherein, the LIFT noise attenuation processing of the second seismic data after the seismic mutual equalization processing comprises the following steps:

separating a third effective signal and a second interference signal of second seismic data vertical to a section of the acquisition position in the second seismic data volume after the seismic mutual equalization processing; and extracting a fourth effective signal from the second interference signal, and taking the sum of the third effective signal and the fourth effective signal as a second seismic data body after LIFT noise attenuation processing.

And extracting a single offset section along the non-longitudinal line direction to obtain a section of the second seismic data body perpendicular to the acquisition direction after seismic mutual equalization processing.

The step of separating the third effective signal and the second interference signal of the second seismic data of the section perpendicular to the acquisition azimuth in the second seismic data volume after the seismic mutual equalization processing comprises the following steps:

converting the second seismic data of the time-space domain into second seismic data of a frequency-wave number domain;

filtering the second seismic data of the frequency-wave number domain by adopting a two-dimensional frequency-wave number domain inclined filtering function to obtain a third effective signal of the frequency-wave number domain and a second interference signal of the frequency-wave number domain;

and converting the third effective signal of the frequency domain-wavenumber domain into a third effective signal of a time-space domain, and converting the second interference signal of the frequency domain-wavenumber domain into a second interference signal of the time-space domain.

Wherein formulas may be employed

And converting the second seismic data of the time-space domain into second seismic data of a frequency-wave number domain.

Wherein f is₃(t, x) is the second seismic data of the time-space domain, F₃And (f, k) is second seismic data in the frequency-wave number domain.

Wherein the two-dimensional frequency-wavenumber domain slant filter function FK₂(DipL₂，DipH₂，FreqL₃，FreqH₃，KSM₂，FSM₂) Comprises the following steps:

wherein, DipL₂And DipH₂Defining the range of the time difference of inclination, DipL, of the third useful signal or the second interfering signal₂Minimum tilt time difference, DipH, for third desired signal or second interfering signal₂For the maximum tilt time difference of the third effective signal or the second interference signal, the corresponding relation between the time-space domain and the frequency-wavenumber domain is

t is time, x is spatial position, k is wavenumber, f is frequency, D is time window range, FreqL₃Is the lowest cut-off frequency, FreqH, of the third effective signal or the second interference signal₃For the highest cut-off frequency, KSM, of the third desired signal or the second interfering signal₂Smoothing factor, FSM, of the third useful signal or second interfering signal in the wave number domain₂A frequency domain smoothing factor, F, for the third desired signal or the second interfering signal₂And (f, k) is a third effective signal or a second interference signal in a frequency-wave number domain.

Wherein extracting the fourth useful signal from the second interfering signal comprises:

converting the second interference signal of the time-space domain into a second interference signal of a frequency-wavenumber domain;

using low-frequency array filter functions F₂(FreqL₄，FreqH₄，Vel₂，Dx₂) Filtering the second interference signal in the frequency-wavenumber domain to obtain a fourth effective signal in the frequency-wavenumber domain;

and converting the fourth effective signal in the frequency-wavenumber domain into a fourth effective signal in a time-space domain.

Wherein, FreqL₄Is the lowest cut-off frequency, FreqH, of the fourth effective signal in the frequency-wavenumber domain₄Is the highest cut-off frequency, Vel, of the fourth effective signal in the frequency-wavenumber domain₂Is the wave velocity of the seismic waves, Dx₂The distance is sampled for the seismic trace space.

Wherein, carrying out energy equalization processing on the second seismic data body after LIFT noise attenuation processing comprises the following steps:

performing time-varying automatic gain processing on the second seismic data volume after the LIFT noise attenuation processing;

taking the ratio of the second seismic data volume after the LIFT noise attenuation processing and the second seismic data volume after the time-varying automatic gain processing as a fourth scale factor;

carrying out low-frequency array filtering on the fourth scale factor to obtain a fifth scale factor;

taking the ratio of the fifth scaling factor to the fourth scaling factor as the sixth scaling factor, and performing median filtering processing on the sixth scaling factor along the non-longitudinal line direction;

and taking the product of the second seismic data volume after the LIFT noise attenuation processing and the sixth scale factor after the median filtering processing as the second seismic data volume after the energy equalization processing.

Step 101, pre-stack double-azimuth AVO mutual equalization processing is carried out on the first seismic data body and the second seismic data body which are subjected to double-azimuth acquisition footprint attenuation processing.

In embodiments of the invention, seismic data acquired at different azimuths will have differences in moveout, velocity and amplitude due to the azimuthal anisotropy, due to the weak anisotropy of the formation, particularly when the subsurface reservoir is approximated by HTI and Tilted Transverse Isotropic (TTI) structures with horizontal axes of symmetry. The target reservoir is assumed to be relatively flat, and the time difference and velocity difference generated by anisotropy are overcome in the previous treatment.

Banik derives an approximation of the reflection coefficient equation for laterally isotropic (TI) media using Thomsen's definition of anisotropy parameters. When the incident wave is a P wave, the following conditions are satisfied:

rapp (theta) is a longitudinal wave reflection coefficient on a reflection interface of the TI medium when the incident angle is theta, Ripp (theta) is a longitudinal wave reflection coefficient on a reflection interface of the isotropic medium when the incident angle is theta, and delta is delta₂-δ₁，δ₁And delta₁Respectively, the values of the anisotropy parameter delta at the upper side and the lower side of the interface.

The approximate expression is to deduce the longitudinal wave reflection coefficient of the transverse isotropic medium, but the AVO relation in the symmetric plane of the azimuth anisotropic medium can be popularized and calculated, and the anisotropy parameter delta is only required to adopt the value corresponding to the azimuth anisotropy.

Thomsen derives a reflection coefficient approximation containing the fourth order term of the incidence angle trigonometric function and the anisotropy parameter ε:

wherein Rp (theta) is a longitudinal wave reflection coefficient on the reflection interface at an incident angle theta,

is the impedance of the P-wave in the vertical direction,

is the modulus of the S-wave in the vertical direction,

is the average value of the vertical P wave speeds at both sides of the interface,

the average value of the vertical S wave velocities at both sides of the interface.

The AVO binomial approximation equation commonly used in the industry is:

R_p(θ)＝P+G sin²θ

wherein P is the intercept of the seismic gather and G is the gradient of the seismic amplitude changing with the offset.

It can be seen that, by simplifying the above formula, no matter the Banik or Thomsen approximate expression, in the TI medium, P in the AVO attribute is not affected by the azimuthal anisotropy, but the G attribute is affected by the TI medium azimuthal anisotropy.

When the reservoir has anisotropic influence, the seismic data acquired at different azimuths have AVO azimuth amplitude difference, and the difference influences the size of AVO gradient value. When the azimuthal anisotropy of the stratum does not change the polarity of the gradient, the gradient is modified by the high-order operator G which varies with the angle of incidence_mAnd (theta) fitting the AVO ratio relation of the seismic gathers acquired in different directions, and using the AVO ratio relation as a correction coefficient to realize the mutual equalization processing of pre-stack AVO of the seismic data acquired in double directions.

In the embodiment of the invention, the pre-stack dual-azimuth AVO mutual equalization processing can be realized on the first seismic data body and the second seismic data body after the dual-azimuth acquisition footprint attenuation processing by adopting any one of the following methods.

The method comprises the steps of firstly, respectively obtaining third seismic data of a preset area in a first seismic data body after dual-azimuth acquisition footprint attenuation processing, and fourth seismic data of the preset area in a second seismic data body after dual-azimuth acquisition footprint attenuation processing; determining a first relationship between a first correction factor and an angle of incidence from the third seismic data and the fourth seismic data; and performing pre-stack double-azimuth AVO mutual equalization processing on the second seismic data volume subjected to the attenuation processing of the double-azimuth acquisition footprint according to a first relation between the first correction coefficient and the incidence angle.

In the method, the third seismic data and the fourth seismic data for the predetermined area may be seismic data for pre-stack seismic gathers at least two spatial locations in the first seismic data volume and the second seismic data volume.

In the method, determining a first relationship between a first correction factor and an angle of incidence from the third seismic data and the fourth seismic data includes:

calculating a first ratio between the third seismic data and the fourth seismic data corresponding to the same incidence angle; and fitting a first relation between the first correction coefficient and the incidence angle according to the first ratio and the corresponding incidence angle.

Wherein a function with a higher order of m may be used

Fitting a first relationship between the first correction coefficient and the incident angle; wherein, a_kAs fitting coefficient, G_m(θ) is a first ratio or a first correction coefficient.

Suppose Y₀，Y₁，…，Y_nRespectively at an incident angle of theta₀，θ₁，…，θ_nA first ratio of (m) where m<n-1, then the least square method is used to solve the fitting coefficient a_kI.e. by

At a minimum, G may be determined_m(θ) a high order number m and fitting coefficients.

According to the method, the pre-stack double-azimuth AVO mutual equalization processing of the second seismic data body after the attenuation processing of the double-azimuth acquisition footprint according to the first relation between the first correction coefficient and the incident angle comprises the following steps:

and multiplying each fifth seismic data in the second seismic data volume after the two-azimuth acquisition footprint attenuation processing by a first correction coefficient corresponding to the incidence angle of the fifth seismic data in the first relation.

Wherein the first correction coefficient corresponding to the incident angle of the fifth seismic data may be expressed by a formula

And (4) calculating.

Acquiring third seismic data of a preset area in the first seismic data body after acquiring footprint energy equalization processing and acquiring fourth seismic data of the preset area in the second seismic data body after dual-azimuth acquiring footprint attenuation processing; determining a second relationship between a second correction factor and an angle of incidence from the third seismic data and the fourth seismic data; and performing pre-stack double-azimuth AVO mutual equalization processing on the first seismic data volume subjected to the double-azimuth acquisition footprint attenuation processing according to a second relation between the second correction coefficient and the incidence angle.

In the method, the third seismic data and the fourth seismic data for the predetermined area may be seismic data for pre-stack seismic gathers at least two spatial locations in the first seismic data volume and the second seismic data volume.

In the method, determining a second relationship between a second correction coefficient and an angle of incidence from the third seismic data and the fourth seismic data includes:

calculating a second ratio between the fourth seismic data and the third seismic data corresponding to the same incidence angle; and fitting a second relation between the second correction coefficient and the incidence angle according to the second ratio and the corresponding incidence angle.

Wherein functions can be employed

Fitting a second relationship between the second correction coefficient and the incident angle; wherein, a_kAs fitting coefficient, G_m(θ) is the second ratio or the second correction coefficient.

Suppose Y₀，Y₁，…，Y_nRespectively at an incident angle of theta₀，θ₁，…，θ_nSecond ratio of (m) where m<n-1, then the least square method is used to solve the fitting coefficient a_kI.e. by

At a minimum, G may be determined_m(θ) a high order number m and fitting coefficients.

According to the method, the pre-stack double-azimuth AVO mutual equalization processing of the first seismic data body after the attenuation processing of the double-azimuth acquisition footprint according to the second relation between the second correction coefficient and the incidence angle comprises the following steps:

and multiplying each sixth seismic data in the first seismic data volume after the two-azimuth acquisition footprint attenuation processing by a second correction coefficient corresponding to the incidence angle of the sixth seismic data in the second relation.

Wherein the angle of incidence corresponds to the sixth seismic dataThe second correction coefficient may be expressed by the formula

And (4) calculating.

In another embodiment of the present invention, the method further comprises:

and carrying out oil reservoir monitoring according to the first seismic data body and the second seismic data body which are subjected to pre-stack double-azimuth AVO mutual equalization processing.

In another embodiment of the present invention, the method further comprises, before:

and when the first seismic data body and the second seismic data body have differences of an observation system, performing surface element resetting, conventional seismic processing and seismic mutual equalization processing on the first seismic data body, and performing surface element resetting, conventional seismic processing and seismic mutual equalization processing on the second seismic data body.

In another embodiment of the present invention, the method further comprises, before:

and when the first seismic data body and the second seismic data body have no difference of an observation system, performing conventional seismic processing and seismic mutual equalization processing on the first seismic data body, and performing conventional seismic processing and seismic mutual equalization processing on the second seismic data body.

According to the embodiment of the invention, the azimuth acquisition footprint influenced by the acquisition azimuth is reduced or even eliminated through the dual-azimuth acquisition footprint attenuation processing, and the AVAZ difference influenced by the acquisition azimuth is reduced or even eliminated through the pre-stack dual-azimuth AVO mutual equalization processing, so that the seismic difference influenced by the acquisition azimuth is reduced or even eliminated, and the non-repetitive dual-azimuth acquisition seismic data is applied to the dynamic monitoring of the oil reservoir.

Referring to fig. 2, another embodiment of the present invention provides a seismic data processing apparatus, including:

the dual-azimuth acquisition footprint attenuation processing module 201 is configured to, when acquisition azimuth angles of the first seismic data volume and the second seismic data volume after the seismic mutual equalization processing are different, perform dual-azimuth acquisition footprint attenuation processing on the first seismic data volume after the seismic mutual equalization processing, and perform dual-azimuth acquisition footprint attenuation processing on the second seismic data volume after the seismic mutual equalization processing;

and the pre-stack double-azimuth AVO mutual equalization processing module 202 is used for performing pre-stack double-azimuth AVO mutual equalization processing on the first seismic data body and the second seismic data body after the attenuation processing of the two-azimuth acquisition footprints.

In the embodiment of the invention, when the acquisition azimuth angles of the first seismic data body and the second seismic data body after seismic mutual equalization processing are different, it is indicated that there is an acquisition azimuth difference between the first seismic data body and the second seismic data body, and the seismic data bodies have obvious seismic differences (such as azimuth acquisition footprint, azimuth amplitude difference and the like) due to the acquisition azimuth difference.

In the embodiment of the present invention, the dual-azimuth acquisition footprint attenuation processing module 201 is specifically configured to perform dual-azimuth acquisition footprint attenuation processing on the first seismic data volume after seismic mutual equalization processing by using the following method:

performing LIFT noise attenuation processing on the first seismic data after the seismic mutual equalization processing;

and performing energy equalization processing on the first seismic data body after the LIFT noise attenuation processing, and taking the first seismic data body after the energy equalization processing as the first seismic data body after the dual-azimuth acquisition footprint attenuation processing.

According to the embodiment of the invention, LIFT noise attenuation processing is adopted to remove the interference of the acquisition strips with small magnitude, and energy equalization processing is adopted to remove the phenomenon of energy nonuniformity with large magnitude and wide distribution, so that the azimuth acquisition footprint caused by the influence of the acquisition azimuth angle is reduced or even eliminated, and the non-repetitive dual-azimuth acquisition seismic data is applied to dynamic monitoring of the oil reservoir.

In the embodiment of the present invention, the two-side acquisition footprint attenuation processing module 201 is specifically configured to implement LIFT noise attenuation processing on the first seismic data volume after seismic mutual equalization processing by using the following method:

separating a first effective signal and a first interference signal of first seismic data of a section perpendicular to an acquisition azimuth in the first seismic data volume after the seismic mutual equalization processing; and extracting a second effective signal from the first interference signal, and taking the sum of the first effective signal and the second effective signal as a first seismic data volume after LIFT noise attenuation processing.

The two-azimuth acquisition footprint attenuation processing module 201 may extract a single offset section along a non-longitudinal line direction to obtain a section of the first seismic data volume after the seismic mutual equalization processing, which is perpendicular to the acquisition direction.

The dual-azimuth acquisition footprint attenuation processing module 201 is specifically configured to separate a first effective signal and a first interference signal of first seismic data of a section perpendicular to an acquisition azimuth in the first seismic data volume after the seismic mutual equalization processing by using the following method:

converting the first seismic data of the time-space domain into first seismic data of a frequency-wavenumber domain;

filtering the first seismic data of the frequency-wavenumber domain by adopting a two-dimensional frequency-wavenumber domain inclined filtering function to obtain a first effective signal of the frequency-wavenumber domain and a first interference signal of the frequency-wavenumber domain;

the first effective signal of the frequency domain-wave number domain is converted into a first effective signal of a time-space domain, and the first interference signal of the frequency domain-wave number domain is converted into a first interference signal of the time-space domain.

Wherein, the collecting footprint attenuation processing module 201 can adopt a formula

The first seismic data in the time-space domain is converted into first seismic data in the frequency-wavenumber domain.

Wherein f is₁(t, x) is the first seismic data of the time-space domain, F₁And (f, k) is the first seismic data in the frequency-wavenumber domain.

Wherein the two-dimensional frequency-wavenumber domain slant filter function FK₁(DipL₁，DipH₁，FreqL₁，FreqH₁，KSM₁，FSM₁) Comprises the following steps:

wherein, DipL₁And DipH₁Defining a range of tilt time differences, DipL, of the first useful signal or the first interfering signal₁Is the minimum tilt time difference, DipH, of the first effective signal or the first interfering signal₁For the maximum tilt time difference of the first useful signal or the first interfering signal, the corresponding relation between the time-space domain and the frequency-wavenumber domain is

t is time, x is spatial position, k is wavenumber, f is frequency, D is time window range, FreqL₁Is the lowest cut-off frequency, FreqH, of the first useful signal or the first interfering signal₁Is the highest cut-off frequency, KSM, of the first useful signal or the first interfering signal₁A smoothing factor, FSM, in the wavenumber domain for the first useful signal or the first interfering signal₁A frequency domain smoothing factor, F, for the first desired signal or the first interfering signal₂And (f, k) is a first effective signal or a first interference signal in a frequency-wavenumber domain.

The two-side acquisition footprint attenuation processing module 201 is specifically configured to extract a second effective signal from the first interference signal by using the following method:

converting the first interference signal of the time-space domain into a first interference signal of a frequency-wavenumber domain;

using low-frequency array filter functions F₂(FreqL₂，FreqH₂，Vel₁，Dx₁) Filtering the first interference signal in the frequency-wavenumber domain to obtain a second effective signal in the frequency-wavenumber domain;

and converting the second effective signal of the frequency-wave number domain into a second effective signal of a time-space domain.

Wherein, FreqL₂Is the lowest cut-off frequency, FreqH, of the second significant signal in the frequency-wavenumber domain₂Is the highest cut-off frequency, Vel, of the second significant signal in the frequency-wavenumber domain₁Is an earthquakeWave velocity, Dx₁The distance is sampled for the seismic trace space.

In the embodiment of the present invention, the two-side acquisition footprint attenuation processing module 201 is specifically configured to implement energy equalization processing on the first seismic data volume after LIFT noise attenuation processing by using the following method:

performing time-varying automatic gain processing on the first seismic data volume after the LIFT noise attenuation processing;

taking the ratio of the first seismic data volume after the LIFT noise attenuation processing to the first seismic data volume after the time-varying automatic gain processing as a first scale factor;

carrying out low-frequency array filtering on the first scale factor to obtain a second scale factor; in particular, a low frequency array filter function F is used₂(FreqL₂，FreqH₂，Vel₁，Dx₁) Performing low-frequency array filtering on the first scale factor;

taking the ratio of the second scale factor to the first scale factor as the third scale factor, and performing median filtering processing on the third scale factor along the non-longitudinal line direction;

and taking the product of the first seismic data volume after the LIFT noise attenuation processing and the third scale factor after the median filtering processing as the first seismic data volume after the energy equalization processing.

The embodiment of the invention only carries out median filtering processing along the non-longitudinal measuring line direction to suppress uneven energy with larger magnitude and wide distribution, and does not carry out median filtering processing along the longitudinal measuring line direction, thereby not damaging the seismic energy along the longitudinal measuring line direction, ensuring the fidelity and the effectiveness of the seismic acquisition footprint attenuation, and simultaneously improving the accuracy of the acquisition footprint attenuation.

In the embodiment of the present invention, the dual-azimuth acquisition footprint attenuation processing module 201 is specifically configured to perform dual-azimuth acquisition footprint attenuation processing on the second seismic data volume after seismic mutual equalization processing by using the following method:

performing LIFT noise attenuation processing on the second seismic data after the seismic mutual equalization processing;

and performing energy equalization processing on the second seismic data body after the LIFT noise attenuation processing, and taking the second seismic data body after the energy equalization processing as the second seismic data body after the dual-azimuth acquisition footprint attenuation processing.

In the embodiment of the present invention, the two-side acquisition footprint attenuation processing module 201 is specifically configured to implement LIFT noise reduction processing on the second seismic data volume after seismic mutual equalization processing by adopting the following manner:

separating a third effective signal and a second interference signal of second seismic data vertical to a section of the acquisition position in the second seismic data volume after the seismic mutual equalization processing; and extracting a fourth effective signal from the second interference signal, and taking the sum of the third effective signal and the fourth effective signal as a second seismic data body after LIFT noise attenuation processing.

The two-azimuth acquisition footprint attenuation processing module 201 may extract a single offset section along a non-longitudinal line direction to obtain a section of the second seismic data volume perpendicular to the acquisition direction after the seismic mutual equalization processing.

The two-azimuth acquisition footprint attenuation processing module 201 is specifically configured to separate a third effective signal and a second interference signal of second seismic data of a section perpendicular to an acquisition azimuth in the second seismic data volume after the seismic mutual equalization processing by using the following method:

converting the second seismic data of the time-space domain into second seismic data of a frequency-wave number domain;

filtering the second seismic data of the frequency-wave number domain by adopting a two-dimensional frequency-wave number domain inclined filtering function to obtain a third effective signal of the frequency-wave number domain and a second interference signal of the frequency-wave number domain;

and converting the third effective signal of the frequency domain-wavenumber domain into a third effective signal of a time-space domain, and converting the second interference signal of the frequency domain-wavenumber domain into a second interference signal of the time-space domain.

Wherein, the collecting footprint attenuation processing module 201 can adopt a formula

And converting the second seismic data of the time-space domain into second seismic data of a frequency-wave number domain.

Wherein f is₃(t, x) is the second seismic data of the time-space domain, F₃And (f, k) is second seismic data in the frequency-wave number domain.

Wherein the two-dimensional frequency-wavenumber domain slant filter function FK₂(DipL₂，DipH₂，FreqL₃，FreqH₃，KSM₂，FSM₂) Comprises the following steps:

wherein, DipL₂And DipH₂Defining the range of the time difference of inclination, DipL, of the third useful signal or the second interfering signal₂Minimum tilt time difference, DipH, for third desired signal or second interfering signal₂For the maximum tilt time difference of the third effective signal or the second interference signal, the corresponding relation between the time-space domain and the frequency-wavenumber domain is

t is time, x is spatial position, k is wavenumber, f is frequency, D is time window range, FreqL₃Is the lowest cut-off frequency, FreqH, of the third effective signal or the second interference signal₃For the highest cut-off frequency, KSM, of the third desired signal or the second interfering signal₂Smoothing factor, FSM, of the third useful signal or second interfering signal in the wave number domain₂A frequency domain smoothing factor, F, for the third desired signal or the second interfering signal₂And (f, k) is a third effective signal or a second interference signal in a frequency-wave number domain.

The two-side acquisition footprint attenuation processing module 201 is specifically configured to extract a fourth effective signal from the second interference signal by using the following method:

converting the second interference signal of the time-space domain into a second interference signal of a frequency-wavenumber domain;

using low-frequency array filter functions F₂(FreqL₄，FreqH₄，Vel₂，Dx₂) Filtering the second interference signal in the frequency-wavenumber domain to obtain a fourth effective signal in the frequency-wavenumber domain;

and converting the fourth effective signal in the frequency-wavenumber domain into a fourth effective signal in a time-space domain.

Wherein, FreqL₄Is the lowest cut-off frequency, FreqH, of the fourth effective signal in the frequency-wavenumber domain₄Is the highest cut-off frequency, Vel, of the fourth effective signal in the frequency-wavenumber domain₂Is the wave velocity of the seismic waves, Dx₂The distance is sampled for the seismic trace space.

The two-side acquisition footprint attenuation processing module 201 is specifically configured to perform energy equalization processing on the second seismic data volume after the LIFT noise attenuation processing by using the following method:

performing time-varying automatic gain processing on the second seismic data volume after the LIFT noise attenuation processing;

taking the ratio of the second seismic data volume after the LIFT noise attenuation processing and the second seismic data volume after the time-varying automatic gain processing as a fourth scale factor;

carrying out low-frequency array filtering on the fourth scale factor to obtain a fifth scale factor;

taking the ratio of the fifth scaling factor to the fourth scaling factor as the sixth scaling factor, and performing median filtering processing on the sixth scaling factor along the non-longitudinal line direction;

and taking the product of the second seismic data volume after the LIFT noise attenuation processing and the sixth scale factor after the median filtering processing as the second seismic data volume after the energy equalization processing.

In embodiments of the invention, seismic data acquired at different azimuths will have differences in moveout, velocity and amplitude due to the azimuthal anisotropy, due to the weak anisotropy of the formation, particularly when the subsurface reservoir is approximated by HTI and Tilted Transverse Isotropic (TTI) structures with horizontal axes of symmetry. The target reservoir is assumed to be relatively flat, and the time difference and velocity difference generated by anisotropy are overcome in the previous treatment.

Banik derives an approximation of the reflection coefficient equation for laterally isotropic (TI) media using Thomsen's definition of anisotropy parameters. When the incident wave is a P wave, the following conditions are satisfied:

rapp (theta) is a longitudinal wave reflection coefficient on a reflection interface of the TI medium when the incident angle is theta, Ripp (theta) is a longitudinal wave reflection coefficient on a reflection interface of the isotropic medium when the incident angle is theta, and delta is delta₂-δ₁，δ₁And delta₁Respectively, the values of the anisotropy parameter delta at the upper side and the lower side of the interface.

The approximate expression is to deduce the longitudinal wave reflection coefficient of the transverse isotropic medium, but the AVO relation in the symmetric plane of the azimuth anisotropic medium can be popularized and calculated, and the anisotropy parameter delta is only required to adopt the value corresponding to the azimuth anisotropy.

Thomsen derives a reflection coefficient approximation containing the fourth order term of the incidence angle trigonometric function and the anisotropy parameter ε:

wherein Rp (theta) is a longitudinal wave reflection coefficient on the reflection interface at an incident angle theta,

is the impedance of the P-wave in the vertical direction,

is the modulus of the S-wave in the vertical direction,

is the average value of the vertical P wave speeds at both sides of the interface,

the average value of the vertical S wave velocities at both sides of the interface.

The AVO binomial approximation equation commonly used in the industry is:

R_p(θ)＝P+G sin²θ

wherein P is the intercept of the seismic gather and G is the gradient of the seismic amplitude changing with the offset.

It can be seen that, by simplifying the above formula, no matter the Banik or Thomsen approximate expression, in the TI medium, P in the AVO attribute is not affected by the azimuthal anisotropy, but the G attribute is affected by the TI medium azimuthal anisotropy.

When the reservoir has anisotropic influence, the seismic data acquired in different directions have AVO direction amplitude difference, and the difference is used for imaging the magnitude of AVO gradient value. When the azimuthal anisotropy of the stratum does not change the polarity of the gradient, the gradient is modified by the high-order operator G which varies with the angle of incidence_mAnd (theta) fitting the AVO ratio relation of the seismic gathers acquired in different directions, and using the AVO ratio relation as a correction coefficient to realize the mutual equalization processing of pre-stack AVO of the seismic data acquired in double directions.

In the embodiment of the present invention, the pre-stack dual-azimuth AVO mutual equalization processing module 202 may implement pre-stack dual-azimuth AVO mutual equalization processing on the first seismic data volume and the second seismic data volume after the dual-azimuth acquisition footprint attenuation processing by using any one of the following methods.

The method comprises the steps that a pre-stack double-azimuth AVO mutual equalization processing module 202 respectively obtains third seismic data of a preset area in a first seismic data body after double-azimuth acquisition footprint attenuation processing and fourth seismic data of the preset area in a second seismic data body after double-azimuth acquisition footprint attenuation processing; determining a first relationship between a first correction factor and an angle of incidence from the third seismic data and the fourth seismic data; and performing pre-stack double-azimuth AVO mutual equalization processing on the second seismic data volume subjected to the attenuation processing of the double-azimuth acquisition footprint according to a first relation between the first correction coefficient and the incidence angle.

In the method, the third seismic data and the fourth seismic data for the predetermined area may be seismic data for pre-stack seismic gathers at least two spatial locations in the first seismic data volume and the second seismic data volume.

In the method, the pre-stack dual-azimuth AVO mutual equalization processing module 202 is specifically configured to determine a first relationship between a first correction coefficient and an incident angle from the third seismic data and the fourth seismic data in the following manner:

calculating a first ratio between the third seismic data and the fourth seismic data corresponding to the same incidence angle; and fitting a first relation between the first correction coefficient and the incidence angle according to the first ratio and the corresponding incidence angle.

Wherein a function with a higher order of m may be used

Fitting a first relationship between the first correction coefficient and the incident angle; wherein, a_kAs fitting coefficient, G_m(θ) is a first ratio or a first correction coefficient.

Suppose Y₀，Y₁，…，Y_nRespectively at an incident angle of theta₀，θ₁，…，θ_nA first ratio of (m) where m<n-1, then the least square method is used to solve the fitting coefficient a_kI.e. by

At a minimum, G may be determined_m(θ) a high order number m and fitting coefficients.

In the method, the pre-stack double-azimuth AVO mutual equalization processing module 202 is specifically configured to perform pre-stack double-azimuth AVO mutual equalization processing on the second seismic data volume after the attenuation processing of the two-azimuth acquisition footprint according to the first relationship between the first correction coefficient and the incident angle by using the following method:

and multiplying each fifth seismic data in the second seismic data volume after the two-azimuth acquisition footprint attenuation processing by a first correction coefficient corresponding to the incidence angle of the fifth seismic data in the first relation.

Wherein the first correction coefficient corresponding to the incident angle of the fifth seismic data may be adoptedFormula (II)

And (4) calculating.

Secondly, a pre-stack double-azimuth AVO mutual equalization processing module 202 respectively acquires third seismic data of a preset area in the first seismic data body after the acquired footprint energy equalization processing and fourth seismic data of a preset area in the second seismic data body after the double-azimuth acquired footprint attenuation processing; determining a second relationship between a second correction factor and an angle of incidence from the third seismic data and the fourth seismic data; and performing pre-stack double-azimuth AVO mutual equalization processing on the first seismic data volume subjected to the double-azimuth acquisition footprint attenuation processing according to a second relation between the second correction coefficient and the incidence angle.

In the method, the third seismic data and the fourth seismic data for the predetermined area may be seismic data for pre-stack seismic gathers at least two spatial locations in the first seismic data volume and the second seismic data volume.

In the method, the pre-stack double-azimuth AVO mutual equalization processing module 202 is specifically configured to determine a second relationship between a second correction coefficient and an incident angle according to the third seismic data and the fourth seismic data in the following manner:

calculating a second ratio between the fourth seismic data and the third seismic data corresponding to the same incidence angle; and fitting a second relation between the second correction coefficient and the incidence angle according to the second ratio and the corresponding incidence angle.

Wherein functions can be employed

Fitting a second relationship between the second correction coefficient and the incident angle; wherein, a_kAs fitting coefficient, G_m(θ) is the second ratio or the second correction coefficient.

Suppose Y₀，Y₁，…，Y_nRespectively at an incident angle of theta₀，θ₁，…，θ_nSecond ratio of (m) where m<n-1, then, the least square method is used to solveCoefficient of solution a_kI.e. by

At a minimum, G may be determined_m(θ) a high order number m and fitting coefficients.

In the method, the pre-stack double-azimuth AVO mutual equalization processing module 202 is specifically configured to perform pre-stack double-azimuth AVO mutual equalization processing on the first seismic data volume after the attenuation processing of the double-azimuth acquisition footprint according to the second relationship between the second correction coefficient and the incident angle by using the following method:

and multiplying each sixth seismic data in the first seismic data volume after the two-azimuth acquisition footprint attenuation processing by a second correction coefficient corresponding to the incidence angle of the sixth seismic data in the second relation.

Wherein the second correction coefficient corresponding to the incident angle of the sixth seismic data may employ a formula

And (4) calculating.

In another embodiment of the present invention, the method further comprises:

and the monitoring module 203 is used for performing oil reservoir monitoring according to the first seismic data body and the second seismic data body which are subjected to the pre-stack double-azimuth AVO mutual equalization processing.

In another embodiment of the present invention, the method further comprises:

and the preprocessing module 204 is configured to perform bin resetting, conventional seismic processing and seismic mutual equalization processing on the first seismic data volume and perform bin resetting, conventional seismic processing and seismic mutual equalization processing on the second seismic data volume when the first seismic data volume and the second seismic data volume have a difference of an observation system.

In another embodiment of the present invention, the method further comprises:

and the preprocessing module 204 is configured to, when there is no difference between the first seismic data volume and the second seismic data volume in the observation system, perform conventional seismic processing and seismic mutual equalization processing on the first seismic data volume, and perform conventional seismic processing and seismic mutual equalization processing on the second seismic data volume.

The specific implementation process of the seismic data processing device is the same as that of the seismic data processing method in the foregoing embodiment, and is not described here again.

Another embodiment of the present invention provides a seismic data processing apparatus, comprising a processor and a computer-readable storage medium, wherein the computer-readable storage medium has instructions stored therein, and when the instructions are executed by the processor, the method implements any one of the above-mentioned seismic data processing methods.

Another embodiment of the invention proposes a computer-readable storage medium, on which a computer program is stored, which computer program, when being executed by a processor, carries out the steps of any of the seismic data processing methods described above.

It will be understood by those of ordinary skill in the art that all or some of the steps of the methods, systems, functional modules/units in the devices disclosed above may be implemented as software, firmware, hardware, and suitable combinations thereof. In a hardware implementation, the division between functional modules/units mentioned in the above description does not necessarily correspond to the division of physical components; for example, one physical component may have multiple functions, or one function or step may be performed by several physical components in cooperation. Some or all of the components may be implemented as software executed by a processor, such as a digital signal processor or microprocessor, or as hardware, or as an integrated circuit, such as an application specific integrated circuit. Such software may be distributed on computer readable media, which may include computer storage media (or non-transitory media) and communication media (or transitory media). The term computer storage media includes volatile and nonvolatile, removable and non-removable media implemented in any method or technology for storage of information such as computer readable instructions, data structures, program modules or other data, as is well known to those of ordinary skill in the art. Computer storage media includes, but is not limited to, RAM, ROM, EEPROM, flash memory or other memory technology, CD-ROM, Digital Versatile Disks (DVD) or other optical disk storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other medium which can be used to store the desired information and which can accessed by a computer. In addition, communication media typically embodies computer readable instructions, data structures, program modules or other data in a modulated data signal such as a carrier wave or other transport mechanism and includes any information delivery media as known to those skilled in the art.

Although the embodiments of the present invention have been described above, the descriptions are only used for understanding the embodiments of the present invention, and are not intended to limit the embodiments of the present invention. It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the embodiments of the invention as defined by the appended claims.

Claims (15)

1. A seismic data processing method, comprising:

when the acquisition azimuth angles of the first seismic data body and the second seismic data body after the seismic mutual equalization processing are different, performing double-azimuth acquisition footprint attenuation processing on the first seismic data body after the seismic mutual equalization processing, and performing double-azimuth acquisition footprint attenuation processing on the second seismic data body after the seismic mutual equalization processing;

the AVO mutual equalization processing of the amplitude of the two superposed positions along with the change of the offset distance is carried out on the first seismic data body and the second seismic data body after the attenuation processing of the two-position acquisition footprint, and the AVO mutual equalization processing comprises the following steps:

respectively acquiring third seismic data of a preset area in the first seismic data body after the dual-azimuth acquisition footprint attenuation processing and fourth seismic data of the preset area in the second seismic data body after the dual-azimuth acquisition footprint attenuation processing;

determining a first relationship between a first correction factor and an angle of incidence from the third seismic data and the fourth seismic data; according to a first relation between a first correction coefficient and an incidence angle, pre-stack double-azimuth AVO mutual equalization processing is carried out on the second seismic data body after the double-azimuth acquisition footprint attenuation processing;

or determining a second relationship between a second correction factor and an angle of incidence from the third seismic data and the fourth seismic data; and performing pre-stack double-azimuth AVO mutual equalization processing on the first seismic data body subjected to the double-azimuth acquisition footprint attenuation processing according to a second relation between a second correction coefficient and an incidence angle.

2. The seismic data processing method of claim 1, wherein the performing bi-directional acquisition footprint attenuation processing on the first seismic data volume after seismic cross-equalization processing comprises:

performing high intelligent filtering technology LIFT noise attenuation processing on the first seismic data volume after the seismic mutual equalization processing;

and performing energy equalization processing on the first seismic data body after the LIFT noise attenuation processing, and taking the first seismic data body after the energy equalization processing as the first seismic data body after the dual-azimuth acquisition footprint attenuation processing.

3. The seismic data processing method of claim 2, wherein performing LIFT noise attenuation processing on the first seismic data volume after seismic cross-equalization processing comprises:

separating a first effective signal and a first interference signal of first seismic data of a section perpendicular to an acquisition azimuth in the first seismic data volume after the seismic mutual equalization processing;

and extracting a second effective signal from the first interference signal, and taking the sum of the first effective signal and the second effective signal as the first seismic data volume after the LIFT noise attenuation processing.

4. The seismic data processing method of claim 2, wherein the energy-equalizing the first seismic data volume after the LIFT noise attenuation comprises:

performing time-varying automatic gain processing on the first seismic data volume after the LIFT noise attenuation processing;

taking the ratio of the first seismic data volume after the LIFT noise attenuation processing to the first seismic data volume after the time-varying automatic gain processing as a first scale factor;

carrying out low-frequency array filtering on the first scale factor to obtain a second scale factor;

taking the ratio of the second scale factor and the first scale factor as a third scale factor;

performing median filtering processing on the third scale factor along a non-inline direction;

and taking the product of the first seismic data volume after the LIFT noise attenuation processing and the third scale factor after the median filtering processing as the first seismic data volume after the energy equalization processing.

5. The seismic data processing method of claim 1, wherein the performing two-azimuth acquisition footprint attenuation processing on the second seismic data volume after seismic mutual equalization processing comprises:

performing high intelligent filtering technology LIFT noise attenuation processing on the second seismic data volume after the seismic mutual equalization processing;

and performing energy equalization processing on the second seismic data body after the LIFT noise attenuation processing, and taking the second seismic data body after the energy equalization processing as the second seismic data body after the dual-azimuth acquisition footprint attenuation processing.

6. The seismic data processing method of claim 5, wherein the LIFT noise attenuation processing of the second seismic data volume after seismic cross-equalization processing comprises:

separating a third effective signal and a second interference signal of second seismic data vertical to a section of the acquisition position in the second seismic data volume after the seismic mutual equalization processing;

and extracting a fourth effective signal from the second interference signal, and taking the sum of the third effective signal and the fourth effective signal as the second seismic data body after the LIFT noise attenuation processing.

7. The seismic data processing method of claim 5, wherein the energy-equalizing the second seismic data volume after LIFT noise attenuation comprises:

performing time-varying automatic gain processing on the second seismic data volume after the LIFT noise attenuation processing;

taking the ratio of the second seismic data volume after the LIFT noise attenuation processing and the second seismic data volume after the time-varying automatic gain processing as a fourth scale factor;

carrying out low-frequency array filtering on the fourth scale factor to obtain a fifth scale factor;

taking the ratio of the fifth scale factor and the fourth scale factor as a sixth scale factor;

performing median filtering processing on the sixth scale factor along a non-inline direction;

and taking the product of the second seismic data volume after the LIFT noise attenuation processing and the sixth scale factor after the median filtering processing as the second seismic data volume after the energy equalization processing.

8. The seismic data processing method of claim 1, wherein determining the first relationship between the first correction factor and the angle of incidence from the third seismic data and the fourth seismic data comprises:

calculating a first ratio between the third seismic data and the fourth seismic data corresponding to the same incidence angle; fitting a first relation between the first correction coefficient and an incident angle according to the first ratio and the corresponding incident angle;

alternatively, the determining a second relationship between a second correction coefficient and an angle of incidence from the third seismic data and the fourth seismic data comprises:

calculating a second ratio between the fourth seismic data and the third seismic data corresponding to the same incidence angle; and fitting a second relation between the second correction coefficient and the incidence angle according to the second ratio and the corresponding incidence angle.

9. The seismic data processing method of claim 1, wherein the performing pre-stack bi-directional AVO mutual equalization on the second seismic data volume after the dual-directional acquisition footprint attenuation processing according to the first relationship between the first correction coefficient and the incident angle comprises:

multiplying each fifth seismic data in the second seismic data volume after the dual-azimuth acquisition footprint attenuation processing by a first correction coefficient corresponding to the incidence angle of the fifth seismic data in the first relation;

or, the pre-stack bi-azimuth AVO mutual equalization processing of the first seismic data volume after the two-azimuth acquisition footprint attenuation processing according to the second relationship between the second correction coefficient and the incident angle includes:

multiplying each sixth seismic data in the first seismic data volume after the dual-azimuth acquisition footprint attenuation processing by a second correction coefficient corresponding to the incidence angle of the sixth seismic data in the second relation.

10. A method of seismic data processing according to any of claims 1 to 9, the method further comprising:

and carrying out oil reservoir monitoring according to the first seismic data body and the second seismic data body which are subjected to pre-stack double-azimuth AVO mutual equalization processing.

11. A method of seismic data processing according to any of claims 1 to 9, further comprising, prior to the method:

and when the first seismic data body and the second seismic data body have differences of an observation system, performing surface element resetting, conventional seismic processing and seismic mutual equalization processing on the first seismic data body, and performing surface element resetting, conventional seismic processing and seismic mutual equalization processing on the second seismic data body.

12. A method of seismic data processing according to any of claims 1 to 9, further comprising, prior to the method:

and when the first seismic data body and the second seismic data body have no difference of an observation system, performing conventional seismic processing and seismic mutual equalization processing on the first seismic data body, and performing conventional seismic processing and seismic mutual equalization processing on the second seismic data body.

13. A seismic data processing apparatus comprising:

the dual-azimuth acquisition footprint attenuation processing module is used for performing dual-azimuth acquisition footprint attenuation processing on the first seismic data body after seismic mutual equalization processing and performing dual-azimuth acquisition footprint attenuation processing on the second seismic data body after the seismic mutual equalization processing when the acquisition azimuth angles of the first seismic data body and the second seismic data body after the seismic mutual equalization processing are different;

the AVO mutual equalization processing module for the pre-stack double-azimuth AVO mutual equalization processing of the first seismic data body and the second seismic data body after the attenuation processing of the two-azimuth acquisition footprint, which is used for the pre-stack double-azimuth AVO mutual equalization processing, comprises:

respectively acquiring third seismic data of a preset area in the first seismic data body after the dual-azimuth acquisition footprint attenuation processing and fourth seismic data of the preset area in the second seismic data body after the dual-azimuth acquisition footprint attenuation processing;

determining a first relationship between a first correction factor and an angle of incidence from the third seismic data and the fourth seismic data; according to a first relation between a first correction coefficient and an incidence angle, pre-stack double-azimuth AVO mutual equalization processing is carried out on the second seismic data body after the double-azimuth acquisition footprint attenuation processing;

or determining a second relationship between a second correction factor and an angle of incidence from the third seismic data and the fourth seismic data; and performing pre-stack double-azimuth AVO mutual equalization processing on the first seismic data body subjected to the double-azimuth acquisition footprint attenuation processing according to a second relation between a second correction coefficient and an incidence angle.

14. A seismic data processing apparatus comprising a processor and a computer readable storage medium having instructions stored therein, wherein the instructions, when executed by the processor, implement a seismic data processing method as claimed in any of claims 1 to 12.

15. A computer-readable storage medium, on which a computer program is stored, which, when being executed by a processor, carries out the steps of the seismic data processing method according to any one of claims 1 to 12.

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