CN106908839A - A kind of seismic wave accurate reflection coefficient analysis method and device - Google Patents

Abstract

The invention discloses a kind of seismic wave accurate reflection coefficient analysis method and device, wherein the method includes：Obtain incident compressional angle θ_p1, compressional wave angle of transmission θ_p2, transverse wave reflection angle θ_s1, shear wave angle of transmission θ_s2, velocity of longitudinal wave v_p, shear wave velocity v_s, longitudinal wave reflection coefficient rp, transverse wave reflection coefficient rs and density reflectance factor rd；Seismic wave reflectance factor is parsed according to the following formula：The characteristics of parsing of seismic reflection coefficient has precision higher is realized according to technical scheme disclosed in the present application, further, use and set up the process of AVO forward simulations and can avoid the limitation of the range of application for the parametric inversions of conventional AVO tri-, so as to solve problems of the prior art.

Description

A kind of seismic wave accurate reflection coefficient analysis method and device

Technical field

The present invention relates to post-stack inversion technical field, more specifically to a kind of parsing of seismic wave accurate reflection coefficient Method and device.

Background technology

Post-stack inversion utilizes poststack seismic data, main inverting stratum compressional wave information.Prestack seismic data contains many Information not available for poststack data, in addition to inverting compressional wave information, can also estimate that formation shear, density, Modulus of Rocks, fluid are quick The sense information such as parameter, so pre-stack seismic inversion is by extensively should be in reservoir prediction and fluid identification.

The parametric inversions of conventional AVO tri- generally using Zoeppritz equations approximate expression (Aki-Richards it is approximate and Fatti is approximate etc.) process of AVO forward simulations is set up, but cross critical angle in P ripple incidence angles and elastic parameter change is violent In the case of, approximate formula limited precision limits the range of application of the parametric inversions of conventional AVO tri-.

In sum, how to provide a kind of precision technical scheme higher to set up the process of AVO forward simulations, be current Those skilled in the art's problem demanding prompt solution.

The content of the invention

It is anti-to improve seismic wave it is an object of the invention to provide a kind of seismic wave accurate reflection coefficient analysis method and device Penetrate the precision of coefficient parsing.

To achieve these goals, the present invention provides following technical scheme：

A kind of seismic wave accurate reflection coefficient analytic method, including：

Obtain incident compressional angle θ_p1, compressional wave angle of transmission θ_p2, transverse wave reflection angle θ_s1, shear wave angle of transmission θ_s2, velocity of longitudinal wave v_p、 Shear wave velocity v_s, longitudinal wave reflection coefficient rp, transverse wave reflection coefficient rs and density reflectance factor rd；

Seismic wave reflectance factor is parsed according to the following formula：

Wherein,

Preferably, velocity of longitudinal wave v is obtained_pAnd shear wave velocity v_s, including：

The velocity of longitudinal wave v of first medium is obtained respectively_p1, shear wave velocity v_s1, the velocity of longitudinal wave v of second medium_p2, shear wave speed Degree v_s2, and the velocity of longitudinal wave difference Δ v between first medium and second medium_p, shear wave velocity difference Δ v_s；

Calculate velocity of longitudinal wave v respectively according to the following formula_pAnd shear wave velocity v_s：

Preferably, longitudinal wave reflection coefficient rp, transverse wave reflection coefficient rs and density reflectance factor rd are obtained, including：

The density p of the first medium is obtained respectively₁, second medium density p₁And first medium and second medium between Density contrast Δ ρ；

Calculate longitudinal wave reflection coefficient rp, transverse wave reflection coefficient rs and density reflectance factor rd respectively according to the following formula：

Wherein,

A kind of seismic wave accurate reflection coefficient resolver, including：

Acquisition module, is used for：Obtain incident compressional angle θ_p1, compressional wave angle of transmission θ_p2, transverse wave reflection angle θ_s1, shear wave angle of transmission θ_s2, velocity of longitudinal wave vp, shear wave velocity v_s, longitudinal wave reflection coefficient rp, transverse wave reflection coefficient rs and density reflectance factor rd；

Parsing module, is used for：Seismic wave reflectance factor is parsed according to the following formula：

Wherein,

Preferably, the acquisition module includes：

First acquisition unit, is used for：The velocity of longitudinal wave v of first medium is obtained respectively_p1, shear wave velocity v_s1, second medium Velocity of longitudinal wave v_p2, shear wave velocity v_s2, and the velocity of longitudinal wave difference Δ v between first medium and second medium_p, shear wave velocity difference Δ v_s；Calculate velocity of longitudinal wave v respectively according to the following formula_pAnd shear wave velocity v_s：

Preferably, the acquisition module includes：

Second acquisition unit, is used for：The density p of the first medium is obtained respectively₁, second medium density p₁With first Density contrast Δ ρ between medium and second medium；Calculate longitudinal wave reflection coefficient rp, transverse wave reflection coefficient respectively according to the following formula Rs and density reflectance factor rd：

Wherein,

The invention provides a kind of seismic wave accurate reflection coefficient analysis method and device, it is demonstrated experimentally that according to the application Disclosed technical scheme realizes the characteristics of parsing of seismic reflection coefficient has precision higher, further, uses foundation The process of AVO forward simulations can avoid the limitation of the range of application for the parametric inversions of conventional AVO tri-, existing so as to solve Problem present in technology.

Brief description of the drawings

In order to illustrate more clearly about the embodiment of the present invention or technical scheme of the prior art, below will be to embodiment or existing The accompanying drawing to be used needed for having technology description is briefly described, it should be apparent that, drawings in the following description are only this Inventive embodiment, for those of ordinary skill in the art, on the premise of not paying creative work, can also basis The accompanying drawing of offer obtains other accompanying drawings.

Fig. 1 is a kind of flow chart of seismic wave accurate reflection coefficient analytic method provided in an embodiment of the present invention；

Fig. 2 is Goodway models essence in a kind of seismic wave accurate reflection coefficient analytic method provided in an embodiment of the present invention Degree assay schematic diagram；

Fig. 3 is Ostrander models in a kind of seismic wave accurate reflection coefficient analytic method provided in an embodiment of the present invention Accuracy test result schematic diagram；

Fig. 4 is a kind of structural representation of seismic wave accurate reflection coefficient resolver provided in an embodiment of the present invention.

Specific embodiment

Below in conjunction with the accompanying drawing in the embodiment of the present invention, the technical scheme in the embodiment of the present invention is carried out clear, complete Site preparation is described, it is clear that described embodiment is only a part of embodiment of the invention, rather than whole embodiments.It is based on Embodiment in the present invention, it is every other that those of ordinary skill in the art are obtained under the premise of creative work is not made Embodiment, belongs to the scope of protection of the invention.

Fig. 1 is referred to, it illustrates a kind of seismic wave accurate reflection coefficient analytic method provided in an embodiment of the present invention Flow chart, can include：

S11：Obtain incident compressional angle θ_p1, compressional wave angle of transmission θ_p2, transverse wave reflection angle θ_s1, shear wave angle of transmission θ_s2, velocity of longitudinal wave v_p, shear wave velocity v_s, longitudinal wave reflection coefficient rp, transverse wave reflection coefficient rs and density reflectance factor rd.

It should be noted that above-mentioned each concept is consistent with the implication for corresponding to concept in the prior art, will not be repeated here.

S12：Seismic wave reflectance factor is parsed according to the following formula：

Wherein,

It is demonstrated experimentally that the parsing for realizing seismic reflection coefficient according to above-mentioned technical proposal disclosed in the present application has precision Higher the characteristics of, further, use and set up the process of AVO forward simulations and can avoid for the parametric inversions of conventional AVO tri- Range of application limitation, so as to solve problems of the prior art.

For realizing the formula of seismic reflection coefficient parsing by six in other above-mentioned technical proposal disclosed in the present application Independent seismologic parameter is reduced to four, i.e., respectively velocity of longitudinal wave reflectance factor, shear wave velocity reflectance factor, density reflection are Number and P-S wave velocity ratio, wherein P-S wave velocity ratio may be configured as constant so as to greatly facilitate accurate Zoeppritz equations Application and practice.

With reference to the essence of classical Goodway models and Ostrander model testings above-mentioned formula disclosed in the present application Exactness (it is assumed that known to P-S wave velocity ratio), can be seen that above-mentioned formula precision disclosed in the present application higher by Fig. 2 and Fig. 3, right The disclosed in the present application above-mentioned method for realizing the parsing of seismic reflection coefficient answered has correctness.

In a kind of seismic wave accurate reflection coefficient analytic method provided in an embodiment of the present invention, velocity of longitudinal wave v is obtained_pAnd it is horizontal Wave velocity v_s, can include：

The velocity of longitudinal wave v of first medium is obtained respectively_p1, shear wave velocity v_s1, the velocity of longitudinal wave v of second medium_p2, shear wave speed Degree v_s2, and the velocity of longitudinal wave difference Δ v between first medium and second medium_p, shear wave velocity difference Δ v_s；

Calculate velocity of longitudinal wave v respectively according to the following formula_pAnd shear wave velocity v_s：

A kind of seismic wave accurate reflection coefficient analytic method provided in an embodiment of the present invention, acquisition longitudinal wave reflection coefficient rp, Transverse wave reflection coefficient rs and density reflectance factor rd, can include：

The density p of first medium is obtained respectively₁, second medium density p₁It is close and first medium and second medium between Degree difference Δ ρ；

Calculate longitudinal wave reflection coefficient rp, transverse wave reflection coefficient rs and density reflectance factor rd respectively according to the following formula：

Wherein,

Corresponding parameter can be simply and rapidly got through the above way, it is ensured that on provided in an embodiment of the present invention That states technical scheme realizes efficiency.

Specifically, the application obtains a new equation by the adjustment to accurate Zoeppritz equations (1) first (2)：

Rpp=(E^-F⁺-G⁺H^-p²)/D (1)

Wherein,

D=E⁺F⁺+G^-H^-p², a=ρ₂(1-2v_s2 ²p²)-ρ₁(1-2v_s1 ²p²)

B=ρ₂(1-2v_s2 ²p²)+2ρ₁v_s1 ²p², c=ρ₁(1-2v_s1 ²p²)+2ρ₂v_s2 ²p²

D=2 ρ₂v_s2 ²-2ρ₁v_s1 ²,

Wherein,

Wherein, θ_p1,θ_p2,θ_s1,θ_s2The transmission of incident compressional angle, compressional wave angle of transmission, transverse wave reflection angle and shear wave is represented respectively Angle, v_p1,v_s1,ρ₁,v_p2,v_s2,ρ₂In representing velocity of longitudinal wave, shear wave velocity and density and the second medium in first medium respectively Velocity of longitudinal wave, shear wave velocity and density.Wherein first medium and second medium are in neighbouring two layer medium.

Pass throughRelation, can obtain formula (3)：

Formula (4)-(10) can similarly be obtained：

Wherein, Δ v_p,Δv_s, Δ ρ be respectively lower upper two layer medium velocity of longitudinal wave is poor, shear wave velocity difference and density contrast.

It is respectively longitudinal wave reflection coefficient, transverse wave reflection coefficient, density reflection system Number and P-S wave velocity ratio.

Formula (3)-(10) are updated in equation (2) can obtain a new Exact Equation (11)

Wherein,

The embodiment of the present invention additionally provides a kind of seismic wave accurate reflection coefficient resolver, as shown in figure 4, can wrap Include：

Acquisition module 11, is used for：Obtain incident compressional angle θ_p1, compressional wave angle of transmission θ_p2, transverse wave reflection angle θ_s1, shear wave transmission Angle θ_s2, velocity of longitudinal wave vp, shear wave velocity v_s, longitudinal wave reflection coefficient rp, transverse wave reflection coefficient rs and density reflectance factor rd；

Parsing module 12, is used for：Seismic wave reflectance factor is parsed according to the following formula：

Wherein,

A kind of seismic wave accurate reflection coefficient resolver provided in an embodiment of the present invention, acquisition module can include：

First acquisition unit, is used for：The velocity of longitudinal wave v of first medium is obtained respectively_p1, shear wave velocity v_s1, second medium Velocity of longitudinal wave v_p2, shear wave velocity v_s2, and the velocity of longitudinal wave difference Δ v between first medium and second medium_p, shear wave velocity difference Δ v_s；Calculate velocity of longitudinal wave v respectively according to the following formula_pAnd shear wave velocity v_s：

A kind of seismic wave accurate reflection coefficient resolver provided in an embodiment of the present invention, acquisition module can include：

Second acquisition unit, is used for：The density p of first medium is obtained respectively₁, second medium density p₁And first medium Density contrast Δ ρ and second medium between；Calculate respectively according to the following formula longitudinal wave reflection coefficient rp, transverse wave reflection coefficient rs and Density reflectance factor rd：

Wherein,

The explanation of relevant portion please be joined in a kind of seismic wave accurate reflection coefficient resolver provided in an embodiment of the present invention See the detailed description of corresponding part in a kind of seismic wave accurate reflection coefficient analytic method provided in an embodiment of the present invention, herein not Repeat again.

The foregoing description of the disclosed embodiments, enables those skilled in the art to realize or uses the present invention.To this Various modifications of a little embodiments will be apparent for a person skilled in the art, and generic principles defined herein can Without departing from the spirit or scope of the present invention, to realize in other embodiments.Therefore, the present invention will not be limited It is formed on the embodiments shown herein, and is to fit to consistent with principles disclosed herein and features of novelty most wide Scope.

Claims (6)

1. a kind of seismic wave accurate reflection coefficient analytic method, it is characterised in that including：

Obtain incident compressional angle θ_p1, compressional wave angle of transmission θ_p2, transverse wave reflection angle θ_s1, shear wave angle of transmission θ_s2, velocity of longitudinal wave v_p, shear wave Speed v_s, longitudinal wave reflection coefficient rp, transverse wave reflection coefficient rs and density reflectance factor rd；

Seismic wave reflectance factor is parsed according to the following formula：

$Rpp=\frac{e_1{f}_1-g_1{h}_1}{e_2{f}_2+g_2{h}_2},$

Wherein,

$e_1=\frac{2+rp}{2-rp}{\mathrm{cos\θ}}_{p1}\[\frac{2+rd}{2-rd}(1-2{\sin }^2{\mathrm{\θ}}_{s2})+2{\sin }^2{\mathrm{\θ}}_{s1}\]-{\mathrm{cos\θ}}_{p2}\[(1-2{\sin }^2{\mathrm{\θ}}_{s1})+2\frac{2+rd}{2-rd}{\sin }^2{\mathrm{\θ}}_{s2}\],$

$e_2=\frac{2+rp}{2-rp}{\mathrm{cos\θ}}_{p1}\[\frac{2+rd}{2-rd}(1-2{\sin }^2{\mathrm{\θ}}_{s2})+2{\sin }^2{\mathrm{\θ}}_{s1}\]+{\mathrm{cos\θ}}_{p2}\[(1-2{\sin }^2{\mathrm{\θ}}_{s1})+2\frac{2+rd}{2-rd}{\sin }^2{\mathrm{\θ}}_{s2}\],$

$f_1=f_2=\left(\frac{2+rp}{2-rp}\right)\frac{v_p}{v_s}{\mathrm{cos\θ}}_{s1}\[\frac{2+rd}{2-rd}(1-2{\sin }^2{\mathrm{\θ}}_{s2})+2{\sin }^2{\mathrm{\θ}}_{s1}\]+\left(\frac{2+rp}{2+rs}\right)\frac{v_p}{v_s}{\mathrm{cos\θ}}_{s2}\[(1-2{\sin }^2{\mathrm{\θ}}_{s1})+2\frac{2+rd}{2-rd}{\sin }^2{\mathrm{\θ}}_{s2}\],$

$g_1={\sin }^2{\mathrm{\θ}}_{p2}\[\frac{2+rd}{2-rd}(1-2{\sin }^2{\mathrm{\θ}}_{s2})-(1-2{\sin }^2{\mathrm{\θ}}_{s1})+2{\mathrm{cos\θ}}_{p1}{\mathrm{cos\θ}}_{s2}\left(\frac{2+rd}{2-rd}\frac{2+rs}{(2-rp)\frac{v_p}{v_s}}-\frac{{(2-rs)}^2}{(2-rp)(2+rs)\frac{v_p}{v_s}}\right)\],$

$g_2={\sin }^2{\mathrm{\θ}}_{p2}\[\frac{2+rd}{2-rd}(1-2{\sin }^2{\mathrm{\θ}}_{s2})-(1-2{\sin }^2{\mathrm{\θ}}_{s1})-2{\mathrm{cos\θ}}_{p1}{\mathrm{cos\θ}}_{s2}\left(\frac{2+rd}{2-rd}\frac{2+rs}{(2-rp)\frac{v_p}{v_s}}-\frac{{(2-rs)}^2}{(2-rp)(2+rs)\frac{v_p}{v_s}}\right)\],$

$h_1=h_2=\frac{2+rd}{2-rd}(1-2{\sin }^2{\mathrm{\θ}}_{s2})-(1-2{\sin }^2{\mathrm{\θ}}_{s1})-2{\mathrm{cos\θ}}_{p2}{\mathrm{cos\θ}}_{s1}\left(\frac{2+rd}{2-rd}\frac{{(2+rs)}^2}{(2+rp)(2-rs)\frac{v_p}{v_s}}-\frac{2-rs}{(2+rp)\frac{v_p}{v_s}}\right),$

$h_1=h_2=\frac{2+rd}{2-rd}(1-2{\sin }^2{\mathrm{\θ}}_{s2})-(1-2{\sin }^2{\mathrm{\θ}}_{s1})-2{\mathrm{cos\θ}}_{p2}{\mathrm{cos\θ}}_{s1}\left(\frac{2+rd}{2-rd}\frac{{(2+rs)}^2}{(2+rp)(2-rs)\frac{v_p}{v_s}}-\frac{2-rs}{(2+rp)\frac{v_p}{v_s}}\right).$

2. method according to claim 1, it is characterised in that obtain velocity of longitudinal wave v_pAnd shear wave velocity v_s, including：

The velocity of longitudinal wave v of first medium is obtained respectively_p1, shear wave velocity v_s1, the velocity of longitudinal wave v of second medium_p2, shear wave velocity v_s2, And the velocity of longitudinal wave difference Δ v between first medium and second medium_p, shear wave velocity difference Δ v_s；

Calculate velocity of longitudinal wave v respectively according to the following formula_pAnd shear wave velocity v_s：

$v_p=v_{p2}-\frac{1}{2}{\mathrm{\Δv}}_p=v_{p1}+\frac{1}{2}{\mathrm{\Δv}}_p,$

$v_s=v_{s2}-\frac{1}{2}{\mathrm{\Δv}}_s=v_{s1}+\frac{1}{2}{\mathrm{\Δv}}_s.$

3. method according to claim 2, it is characterised in that obtain longitudinal wave reflection coefficient rp, transverse wave reflection coefficient rs and Density reflectance factor rd, including：

The density p of the first medium is obtained respectively₁, second medium density p₁It is close and first medium and second medium between Degree difference Δ ρ；

Calculate longitudinal wave reflection coefficient rp, transverse wave reflection coefficient rs and density reflectance factor rd respectively according to the following formula：

$rp=\frac{{\mathrm{\Δv}}_p}{v_p},$

$rs=\frac{{\mathrm{\Δv}}_s}{v_s},$

$rd=\frac{\mathrm{\Δ}\mathrm{\ρ}}{\mathrm{\ρ}},$

Wherein,

$v_{\mathrm{\ρ}}=\mathrm{\ρ}2-\frac{1}{2}\mathrm{\Δ}\mathrm{\ρ}=\mathrm{\ρ}1+\frac{1}{2}\mathrm{\Δ}\mathrm{\ρ}.$

4. a kind of seismic wave accurate reflection coefficient resolver, it is characterised in that including：

Acquisition module, is used for：Obtain incident compressional angle θ_p1, compressional wave angle of transmission θ_p2, transverse wave reflection angle θ_s1, shear wave angle of transmission θ_s2, it is vertical Wave velocity v_p, shear wave velocity v_s, longitudinal wave reflection coefficient rp, transverse wave reflection coefficient rs and density reflectance factor rd；

Parsing module, is used for：Seismic wave reflectance factor is parsed according to the following formula：

$Rpp=\frac{e_1{f}_1-g_1{h}_1}{e_2{f}_2+g_2{h}_2},$

Wherein,

$e_1=\frac{2+rp}{2-rp}{\mathrm{cos\θ}}_{p1}\[\frac{2+rd}{2-rd}(1-2{\sin }^2{\mathrm{\θ}}_{s2})+2{\sin }^2{\mathrm{\θ}}_{s1}\]-{\mathrm{cos\θ}}_{p2}\[(1-2{\sin }^2{\mathrm{\θ}}_{s1})+2\frac{2+rd}{2-rd}{\sin }^2{\mathrm{\θ}}_{s2}\],$

$e_2=\frac{2+rp}{2-rp}{\mathrm{cos\θ}}_{p1}\[\frac{2+rd}{2-rd}(1-2{\sin }^2{\mathrm{\θ}}_{s2})+2{\sin }^2{\mathrm{\θ}}_{s1}\]+{\mathrm{cos\θ}}_{p2}\[(1-2{\sin }^2{\mathrm{\θ}}_{s1})+2\frac{2+rd}{2-rd}{\sin }^2{\mathrm{\θ}}_{s2}\],$

$f_1=f_2=\left(\frac{2+rp}{2-rp}\right)\frac{v_p}{v_s}{\mathrm{cos\θ}}_{s1}\[\frac{2+rd}{2-rd}(1-2{\sin }^2{\mathrm{\θ}}_{s2})+2{\sin }^2{\mathrm{\θ}}_{s1}\]+\left(\frac{2+rp}{2+rs}\right)\frac{v_p}{v_s}{\mathrm{cos\θ}}_{s2}\[(1-2{\sin }^2{\mathrm{\θ}}_{s1})+2\frac{2+rd}{2-rd}{\sin }^2{\mathrm{\θ}}_{s2}\],$

$g_1={\sin }^2{\mathrm{\θ}}_{p2}\[\frac{2+rd}{2-rd}(1-2{\sin }^2{\mathrm{\θ}}_{s2})-(1-2{\sin }^2{\mathrm{\θ}}_{s1})+2{\mathrm{cos\θ}}_{p1}{\mathrm{cos\θ}}_{s2}\left(\frac{2+rd}{2-rd}\frac{2+rs}{(2-rp)\frac{v_p}{v_s}}-\frac{{(2-rs)}^2}{(2-rp)(2+rs)\frac{v_p}{v_s}}\right)\],$

$g_2={\sin }^2{\mathrm{\θ}}_{p2}\[\frac{2+rd}{2-rd}(1-2{\sin }^2{\mathrm{\θ}}_{s2})-(1-2{\sin }^2{\mathrm{\θ}}_{s1})-2{\mathrm{cos\θ}}_{p1}{\mathrm{cos\θ}}_{s2}\left(\frac{2+rd}{2-rd}\frac{2+rs}{(2-rp)\frac{v_p}{v_s}}-\frac{{(2-rs)}^2}{(2-rp)(2+rs)\frac{v_p}{v_s}}\right)\],$

$h_1=h_2=\frac{2+rd}{2-rd}(1-2{\sin }^2{\mathrm{\θ}}_{s2})-(1-2{\sin }^2{\mathrm{\θ}}_{s1})-2{\mathrm{cos\θ}}_{p2}{\mathrm{cos\θ}}_{s1}\left(\frac{2+rd}{2-rd}\frac{{(2+rs)}^2}{(2+rp)(2-rs)\frac{v_p}{v_s}}-\frac{2-rs}{(2+rp)\frac{v_p}{v_s}}\right),$

$h_1=h_2=\frac{2+rd}{2-rd}(1-2{\sin }^2{\mathrm{\θ}}_{s2})-(1-2{\sin }^2{\mathrm{\θ}}_{s1})-2{\mathrm{cos\θ}}_{p2}{\mathrm{cos\θ}}_{s1}\left(\frac{2+rd}{2-rd}\frac{{(2+rs)}^2}{(2+rp)(2-rs)\frac{v_p}{v_s}}-\frac{2-rs}{(2+rp)\frac{v_p}{v_s}}\right).$

5. device according to claim 4, it is characterised in that the acquisition module includes：

First acquisition unit, is used for：The velocity of longitudinal wave v of first medium is obtained respectively_p1, shear wave velocity v_s1, the compressional wave of second medium Speed v_p2, shear wave velocity v_s2, and the velocity of longitudinal wave difference Δ v between first medium and second medium_p, shear wave velocity difference Δ v_s；Press Calculate velocity of longitudinal wave v respectively according to following equation_pAnd shear wave velocity v_s：

$v_p=v_{p2}-\frac{1}{2}{\mathrm{\Δv}}_p=v_{p1}+\frac{1}{2}{\mathrm{\Δv}}_p,$

$v_s=v_{s2}-\frac{1}{2}{\mathrm{\Δv}}_s=v_{s1}+\frac{1}{2}{\mathrm{\Δv}}_s.$

6. device according to claim 5, it is characterised in that the acquisition module includes：

Second acquisition unit, is used for：The density p of the first medium is obtained respectively₁, second medium density p₁And first medium Density contrast Δ ρ and second medium between；Calculate respectively according to the following formula longitudinal wave reflection coefficient rp, transverse wave reflection coefficient rs and Density reflectance factor rd：

$rp=\frac{{\mathrm{\Δv}}_p}{v_p},$

$rs=\frac{{\mathrm{\Δv}}_s}{v_s},$

$rd=\frac{\mathrm{\Δ}\mathrm{\ρ}}{\mathrm{\ρ}},$

Wherein,

$v_{\mathrm{\ρ}}=\mathrm{\ρ}2-\frac{1}{2}\mathrm{\Δ}\mathrm{\ρ}=\mathrm{\ρ}1+\frac{1}{2}\mathrm{\Δ}\mathrm{\ρ}.$