CN102841377A - Oil gas detection method based on generalized ST transformation and utilizing stratum elasticity absorption coefficients of different offset gathers - Google Patents

Abstract

The invention discloses an oil gas detection method based on generalized ST transformation and utilizing stratum elastic absorption coefficients of different offset gathers. The method comprises the following steps of: (1) exciting earthquake waves and recording the earthquake waves in a working area to form the gathers which can be directly used for analyzing the change of vibration amplitudes along with the change of an offset distance and is subjected to normal time difference correction; (2) converting data in an offset domain into an angle domain to obtain an angle gather, and sorting angles to form at least three stacked data bodies, namely a near gather, a middle gather and a far gather; (3) performing generalized ST transformation on processed angle stacked data, converting time domain data into frequency domain data, performing generalized ST transformation on each gather to obtain Si(t,f), wherein f equals to fb-fe, and performing Hilbert transformation on Si(t,f) to obtain a vibration amplitude spectrum PSi(t,f); (4) determining a high frequency, a low frequency and a boundary frequency fc of a target layer through experiment analysis so as to obtain an absorption coefficient alpha (t) of each gather; (5) performing normalization on the absorption coefficients; and (6) comparing and analyzing results obtained from calculation on the different angle stacked data, thus identifying a potential oil gas region.

Description

A kind of utilization based on Generalized S T conversion is the stratum elasticity absorption coefficient gas-oil detecting method of common-range gather not

Technical field

The present invention relates to the geophysical prospecting for oil technology, be a kind of Generalized S T conversion to be applied on the different offset distance road collection seismic data volumes, thereby the elasticity absorption coefficient that calculates the stratum is used for oil and gas detection.

Background technology

Seismic prospecting is through manual type (explosive, vibroseis, air gun etc.) earthquake-wave-exciting; On the face of land or underground in a certain way with the vibration situation of simple component or many component sensors record underground medium; Because when seismic event is propagated in medium; Its path, oscillation intensity, frequency, phase place, waveform etc. will with the difference of geometric shape at character and the interface through medium change; Geological data through to sensor record handles, analyze obtaining underground medium character and Geological Structural Forms, and then seeks the geophysical exploration method of resource such as oil gas.

The seventies in 20th century, the geophysicist finds that hydro carbons has special response to radio-frequency component, i.e. high frequency heavy losses, and dominant frequency obviously reduces.The two-phase media theory confirms that also reservoir of oil and gas is made up of solid skeletal and pore fluid, and the viscosity of loose skeleton and pore fluid will cause attenuation of seismic wave.Biot and Wyllie have studied the characteristic of seismic wave attenuation, and the decay in skeleton is caused by solid friction on the one hand, and is relevant with frequency on the other hand; And the decay in pore fluid fully by frequency cause (Biot M A. Theory of propagation of elastic waves in a fluid saturated porous solid:Part1-low frequency range and Part2-higher frequency range [J]. Journal of the Acoustical Society of America; 1956; 28. Wyllie M R.Studies of elastic wave attenuation in porous media [A] .31stAnnualSEGMeeting; Denver; Colorado, 1961).

Along with absorbent properties and the various absorbability qualitative factor that influences to rock have been done long research; People are also more and more comprehensive to the character that absorbs; Generally speaking the elastic wave absorbent properties depends mainly on the elastic property of rock skeleton; Influence bigger factor and also have factor of porosity, more obvious when containing gas component in hole compressibility and hole the saturated solution composition, particularly hole to the influence of absorbent properties.Based on previous finding the absorbent properties of real medium under the seimic wave propagation situation is done following the conclusion.

(1) stratum is relevant with wave frequency to the absorption of all kinds of ripples, increases with frequency.

(2) there is inverse relation between the absorbent properties on stratum and the seismic event speed in the stratum, rock at a high speed, a little less than the absorbability, and the rock of low speed, absorbability is strong.

(3) the formation rock absorbent properties at first is decided by rock preservation state and inner structure.Mineral grain and granularity are little to the absorbent properties influence, and the stratum static pressure increases with the degree of depth, and rock is compressed, and compact structure causes that absorbability dies down, and the rock texture that is damaged strengthens the absorbability that makes it.

(4) in the multinomial medium that solid-liquid gas constitutes, influence is gaseous material the most significantly to absorbent properties.

(5) absorption coefficient of sandstone is big than shale, ls, the sandstone of oily particularly, and absorption coefficient enlarges markedly.

(6) absorbent properties of rock is also relevant with its depth of burial, increases with depth of burial to reduce.

Therefore we can utilize this frequency characteristic of pore fluid, obtain the earthquake attenuation by absorption exception response of reservoir of oil and gas, are used for oil and gas detection.

The core technology of asking for of absorption coefficient is the time frequency analysis algorithm, and the time frequency analysis algorithm mainly contains Fourier conversion in short-term (STFT), continuous wavelet transform (CWT), S conversion (ST) and generalized S-transform at present.

Fourier transform is the analytical approach of pure frequency formula, and it is right-on in the location of frequency, and does not have any location in time domain, promptly can't judge when a specific signal takes place according to the frequency spectrum of Fourier transform.If the signal of analyzing is a kind of stationary signal, perhaps this point is not very important, and most of signal all contains a large amount of astable compositions, therefore needs to extract pairing frequency information of a certain period (or moment), introduces wavelet transformation thus.

The definition of wavelet transformation is after being displacement τ to a certain function that is called as basic small echo (also being female small echo), under different scale a, does inner product with signal x to be analyzed (t).

${\mathrm{WT}}_X(a,\mathrm{\τ})=\frac{1}{\sqrt{a}}{\∫}_{-\∞}^{+\∞}x\left(t\right)\mathrm{\ψ}\left(\frac{t-\mathrm{\τ}}{a}\right)\mathrm{dt}$

Wherein, a is a yardstick, and τ is displacement, and t is the time, and ψ (t) is a wavelet function, and x (t) is a signal to be analyzed, WT _X(a τ) is the signal of signal behind wavelet transformation to be analyzed.

In seismic data is handled, can Application of wavelet carry out time frequency analysis, but because seismic trace when decomposing, small echo is chosen has diversity, makes its result have multi-solution.In addition, seismic event owing to the formation absorption effect, has not only changed the yardstick of source wavelet in the air, has also changed its shape.Wavelet transformation can only change the yardstick of seismic trace, can not change its shape.Therefore need to introduce the ST conversion.

1996, U.S. geophysicist Stockwell proposed a kind of new Time-Frequency Analysis Method on the forefathers basis, be called the S conversion.

If function h (t) ∈ is L ²(R), L ²(R) quadractically integrable function on the expression real number field, the S transform definition of h (t) is:

$S(\mathrm{\&tau;},f)={\&Integral;}_{-\&infin;}^{\&infin;}h\left(t\right)g_f(t-\mathrm{\&tau;})\exp (-\mathrm{<figure-callout\; id="2"\; label="i"\; filenames="HDA00002187438200012.png,HDA00002187438200021.png"\; state="\{\{state\}\}">i</figure-callout>}2\mathrm{\&pi;ft})\mathrm{dt}$

Wherein t is the time, and τ is displacement, and f is a frequency, below all identical.

$g_f\left(t\right)=\frac{\left|f\right|}{\sqrt{2\mathrm{\&pi;}}}\exp (-\frac{t^2{\mathrm{<figure-callout\; id="2"\; label="f"\; filenames="HDA00002187438200012.png,HDA00002187438200021.png"\; state="\{\{state\}\}">f</figure-callout>}}^2}{2})$

The S conversion of h (t) and fourier transform spectrum H (f) have following relation:

$H\left(f\right)={\&Integral;}_{-\&infin;}^{\&infin;}S(\mathrm{\&tau;},f)\mathrm{d\&tau;}$

And being inversely transformed into of S conversion:

$h\left(t\right)=\frac{1}{2\mathrm{\&pi;}}{\&Integral;}_{-\&infin;}^{\&infin;}{\&Integral;}_{-\&infin;}^{\&infin;}S(\mathrm{\&tau;},f)\exp \left(\mathrm{<figure-callout\; id="2"\; label="i"\; filenames="HDA00002187438200012.png,HDA00002187438200021.png"\; state="\{\{state\}\}">i</figure-callout>}2\mathrm{\&pi;ft}\right)\mathrm{d\&tau;df}$

Definition by the S conversion is visible, and it has made up the advantage of short window Fourier transform and wavelet transformation, has avoided their deficiency simultaneously.In addition, because equality

${\&Integral;}_{-\&infin;}^{\&infin;}\frac{\left|f\right|}{\sqrt{2\mathrm{\&pi;}}}e\left(\frac{f^2{(\mathrm{\&tau;}-t)}^2}{2}\right)\mathrm{d\&tau;}=1$

Set up the window function g of this explanation S conversion _f(t) satisfy normalizing condition.S conversion simultaneously can obtain different frequecy characteristics constantly.

In the S conversion, basic wavelet function is:

$w\left(t\right)=\frac{1}{\sqrt{2\mathrm{\&pi;}}}\exp (-\frac{{\mathrm{<figure-callout\; id="2"\; label="t"\; filenames="HDA00002187438200012.png,HDA00002187438200021.png"\; state="\{\{state\}\}">t</figure-callout>}}^2}{2-\mathrm{<figure-callout\; id="2"\; label="i"\; filenames="HDA00002187438200012.png,HDA00002187438200021.png"\; state="\{\{state\}\}">i</figure-callout>}2\mathrm{\&pi;t}})$

$w_f\left(t\right)=g_f\left(t\right)\exp (-2\mathrm{\&pi;ft})$

To the characteristics of seismic signal, Gao Jinghuai etc. are extended to the basic wavelet function in the S conversion:

$w\left(t\right)\mathrm{Aexp}(-\mathrm{\&alpha;}{(t-\mathrm{\&beta;})}^2-i2\mathrm{\&pi;}{f}_{0}t)$

Wherein, A is the amplitude of basic small echo, and α is the energy attenuation rate, and β is the energy delay time, f ₀Video frequency for basic small echo.Definition

$w_f\left(t\right)=g_f\left(t\right)\exp (-\mathrm{<figure-callout\; id="2"\; label="i"\; filenames="HDA00002187438200012.png,HDA00002187438200021.png"\; state="\{\{state\}\}">i</figure-callout>}2\mathrm{\&pi;}{f}_0\mathrm{ft})$

Wherein:

$g_f\left(t\right)=A\left|f\right|\exp (-\mathrm{\&alpha;}{(\mathrm{ft}-\mathrm{\&beta;})}^2)$

S conversion to basic wavelet function is defined as generalized S-transform.

If function h (t) ∈ is L ²(R), h (t) is defined as with respect to the generalized S-transform of basic wavelet function:

$S(\mathrm{\&tau;},f)={\&Integral;}_{-\&infin;}^{\&infin;}{g}_f(t-\mathrm{\&tau;})h\left(t\right)\exp (-\mathrm{<figure-callout\; id="2"\; label="i"\; filenames="HDA00002187438200012.png,HDA00002187438200021.png"\; state="\{\{state\}\}">i</figure-callout>}2\mathrm{\&pi;}{f}_0\mathrm{ft})\mathrm{dt}$

We introduce Generalized S T conversion (Xu Feng, Feng Shiqi in the middle of the time frequency analysis carry out seismic data thus.Formation absorption coefficient calculations method based on time frequency analysis.Marine oil, 2007,27 (4)); Be used for the calculating of absorption coefficient, but way in the past all is based on the pure wave data information of poststack, does not introduce the information of prestack; Along with the development that deeply reaches digital technology of seismic prospecting, sound wave model is the demand of seismic exploration contentedly, for the more propagation of real simulated seismic event in underground medium; The dielectric model that people's research is more complicated; Like the elastic oscillation equation, therefore viscoelastic wave equation and anisotropic model are necessary to introduce the elasticity absorption coefficient based on pre-stack data.In addition this method can also effectively differentiate the vacation that calculates by single poststack data absorb unusual, promptly through the contrast of different angles stack road collection result of calculation, distinguishes true and false unusually, water layer and hydrocarbon zone.

Domestic and foreign literature to decay with the variation of incident angle have certain research (Chen Xiaohong, Tian Lixin, yellow rich.Earthquake frequency division AVO method present Research and prospect.The marine facies oil geology, 2009,14 (4).MARK CHAPMAN; ENRU LIU, XIANG-YANG LI, The influence of abnormally high reservoir attenuation on the AVO signature. THE LEADING EDGE; 2005.11.), to this method stronger theory support is provided.For elastic medium, amplitude fading and frequency are irrelevant basically, and be only relevant with offset distance. and for attenuation medium or reservoir, amplitude fading is promptly relevant with offset distance simultaneously also relevant with frequency, and the high frequency amplitude fading is faster.For hydrocarbon zone, high frequency attenuation is maximum a long way, and low-frequency component increases on the contrary.This shows that data are more conducive to us and calculate absorption coefficient a long way, absorption reaction is stronger.And through with the contrast of near, middle track data result of calculation, can eliminate the false and retain the true better recognition potential hydrocarbon layer.

Summary of the invention

The present invention provides a kind of more effective gas-oil detecting method through Generalized S T conversion and pre stack data data calculating formation absorption coefficient.

Technical scheme of the present invention is following:

A kind of utilization based on Generalized S T conversion is the stratum elasticity absorption coefficient gas-oil detecting method of common-range gather not, and step comprises:

(1) earthquake-wave-exciting and write down the work area seismic event shakes the Data Processing flow process by the numbers and the seismic data of record is carried out the high-fidelity that relative amplitude keeps handles, and formation can directly be used for the road collection of amplitude after with the normal-moveout correction of offset distance mutation analysis;

(2) the offset distance numeric field data is transformed in the angle domain, obtains angular-trace gather, the sorting angle, carry out near, in, data stack a long way, form near at least, in, three superposition of data bodies a long way;

(3) the angle superposition of data after handling being carried out Generalized S T conversion, is frequency domain data with the time domain data-switching, and each road is done generalized S-transform and obtained S _i(t, f) f=f _b-f _eTo S _i(t f) does the Hilbert conversion, thereby obtains spectral amplitude PS _i(t, f);

$S(\mathrm{\&tau;},f)={\&Integral;}_{-\&infin;}^{\&infin;}{g}_f(t-\mathrm{\&tau;})h\left(t\right)\exp (-\mathrm{<figure-callout\; id="2"\; label="i"\; filenames="HDA00002187438200012.png,HDA00002187438200021.png"\; state="\{\{state\}\}">i</figure-callout>}2\mathrm{\&pi;}{f}_0\mathrm{ft})\mathrm{dt}$

Wherein $g_f\left(t\right)=A\left|f\right|\mathrm{Exp}(-\mathrm{\&alpha;}{(\mathrm{Ft}-\mathrm{\&beta;})}^2)$

A is the amplitude of basic small echo, and α is the energy attenuation rate, and β is the energy delay time, and t is the time, and τ is displacement, and f is a frequency, f ₀Be the video frequency of basic small echo, below all identical;

(4) confirm the low-and high-frequency and the boundary frequency f of zone of interest through experimental analysis _c, and do following calculating, can obtain the absorption coefficient (t) in each road;

$S_b\left(t\right)=\underset{k=b}{\overset{c}{\mathrm{\&Sigma;}}}P{S}_i(t,f_k)$

$S_h\left(t\right)=\underset{k=c+1}{\overset{e}{\mathrm{\&Sigma;}}}{\mathrm{PS}}_i(t,f_k)$

$\mathrm{\&alpha;}\left(t\right)=\ln \frac{S_b\left(t\right)}{S_h\left(t\right)}$

Wherein, f _bBe low-frequency minimum, f _eBe high frequency limit, S _b(t) be low frequency energy, S _h(t) be high-frequency energy;

(5) absorption coefficient that different angles superposition of data body is calculated carries out normalization to be handled;

(6) result who the different angles superposition of data is calculated compares analysis, thus the potential zone of identification oil gas.

Further, the present invention also can form four or five data stacks, the more potential oil gas zone of Accurate Analysis identification.

Further, the normalization of numerical value described in the step 5 is handled, and is that its numerical value is normalized between 0 to 1, and is wherein strong more near 1 representative absorption more, thereby relatively convenient.

Further; The result who in the step 6 the different angles superposition of data is calculated compares analysis; Discrimination standard is: should there be obvious attenuation by absorption character in oil-gas Layer in the shortcut data volume, and the absorption coefficient that promptly calculates is bigger, based on middle road, data a long way; Further strengthen along with incidence angle increases absorbent properties, the attenuation properties of data reaches the strongest a long way; Differentiate with this, eliminate the false and retain the true, identification potential hydrocarbon zone.

The present invention has following beneficial effect:

1, utilizes this characteristic of pore fluid high frequency attenuation, obtained the earthquake attenuation by absorption exception response of reservoir of oil and gas, be used for oil and gas detection.

2, effectively utilize pre stack data information, set up flow process and method that the elasticity absorption coefficient calculates.

3, through near, in, the comparison of angle stack absorption coefficient far away, can eliminate the false and retain the true better recognition potential hydrocarbon layer, thereby effectively lower exploration risk.

4, in time frequency analysis, introduced Generalized S T conversion, window Fourier and wavelet transformation scheduling algorithm when comparing, it has combined the advantage of the two, has more superiority, is fit to the analysis of seismic data more.

Description of drawings

Fig. 1 shortcut stack absorption coefficient sectional view.

Trace-stacking absorption coefficient section face among Fig. 2.

Fig. 3 absorption coefficient sectional view that superposes a long way.

Fig. 4 the 320th road 2.3s-2.5s crosses hydrocarbon zone (2.38s-2.39s) absorption coefficient curve.

Embodiment

Embodiment 1

(1) choose certain and distinguish actual seismic data, shake the Data Processing flow process by the numbers and the seismic data of record is carried out the high-fidelity that relative amplitude keeps handle, formation can directly be used for the road collection of amplitude after with the normal-moveout correction of offset distance mutation analysis;

(2) the offset distance numeric field data is transformed in the angle domain, obtains angular-trace gather, the sorting angle, carry out near, in, data stack a long way, form near, in, superposition of data body (also can form four or five stack) a long way.

(3) the angle superposition of data after handling being carried out Generalized S T conversion, is frequency domain data with the time domain data-switching, and each road is done generalized S-transform and obtained S _i(t, f) f=f _b-f _eTo S _i(t f) does the Hilbert conversion, thereby obtains spectral amplitude PS _i(t, f).

$S(\mathrm{\&tau;},f)={\&Integral;}_{-\&infin;}^{\&infin;}{g}_f(t-\mathrm{\&tau;})h\left(t\right)\exp (-\mathrm{<figure-callout\; id="2"\; label="i"\; filenames="HDA00002187438200012.png,HDA00002187438200021.png"\; state="\{\{state\}\}">i</figure-callout>}2\mathrm{\&pi;}{f}_0\mathrm{ft})\mathrm{dt}$

Wherein $g_f\left(t\right)=A\left|f\right|\mathrm{Exp}(-\mathrm{\&alpha;}{(\mathrm{Ft}-\mathrm{\&beta;})}^2)$

A is the amplitude of basic small echo, and α is the energy attenuation rate, and β is the energy delay time, and for t is the time, τ is displacement, and f is a frequency, f ₀Be the video frequency of basic small echo, below all identical.

(4) confirm the low-and high-frequency and the boundary frequency f of zone of interest through experimental analysis _c, and do following calculating, can obtain the absorption coefficient (t) in each road.

$S_b\left(t\right)=\underset{k=b}{\overset{c}{\mathrm{\&Sigma;}}}{\mathrm{PS}}_i(t,f_k)$

$S_h\left(t\right)=\underset{k=c+1}{\overset{e}{\mathrm{\&Sigma;}}}{\mathrm{PS}}_i(t,f_k)$

$\mathrm{\&alpha;}\left(t\right)=\ln \frac{S_b\left(t\right)}{S_h\left(t\right)}$

Wherein, f _bBe low-frequency minimum, f _eBe high frequency limit, S _b(t) be low frequency energy, S _b(t) be high-frequency energy.

(5) absorption coefficient that different angles superposition of data body is calculated carries out normalization to be handled, and its numerical value is normalized between 0 to 1, wherein strong more near 1 representative absorption more, thereby relatively convenient.

(6) result who the different angles superposition of data is calculated compares analysis (Fig. 1, Fig. 2, Fig. 3), thus the potential zone of identification oil gas.Concrete discrimination standard is: should there be obvious attenuation by absorption character in hydrocarbon zone in the shortcut data volume; The absorption coefficient that promptly calculates is bigger; And further strengthen along with incident angle increases (promptly middle road, data) a long way absorbent properties, the attenuation properties of data reaches the strongest a long way.According to this differentiation thinking, eliminate the false and retain the true identification potential hydrocarbon zone.

Like figure, Fig. 1, Fig. 2, Fig. 3 be respectively well near, in, superposition of data absorption profile far away, position that frame of broken lines enclose is to construct the top; Comparison diagram 1,2,3; Shortcut absorb to show that there is stronger absorbent properties in this zone, in, absorbent properties strengthens successively a long way, differentiate it and be hydrocarbon zone.Drilling well shows that this reservoir section is the combination of many cover hydrocarbon zone.

Table 1 the 320th road 2.3s-2.5s crosses hydrocarbon zone (2.38s-2.39s) absorption coefficient value

Time (second)	Shortcut absorbs	Middle road absorbs	Absorb a long way
				2.3	0.1011	0.2012	0.1875
2.308	0.019	0.041	0.0662
				2.316	0.0135	0.0451	0.1048
2.324	0.006	0.0209	0.1719
				2.332	0.0089	0.0548	0.1372
2.34	0.0104	0.0112	0.1711
				2.348	0.0193	0.031	0.036
2.356	0.0345	0.0792	0.2702
				2.364	0.0613	0.0402	0.2484
2.372	0.0413	0.058	0.1562
				2.38	0.2325	0.3411	0.7041
2.388	0.2545	0.3942	0.5774
				2.396	0.1814	0.2365	0.2527
2.404	0.1838	0.2213	0.2692
				2.412	0.0279	0.2781	0.3392
2.42	0.0535	0.1403	0.0824
				2.428	0.0522	0.1315	0.1774
2.436	0.0209	0.0928	0.223
				2.444	0.0193	0.0114	0.107
2.452	0.0122	0.0249	0.0369
				2.46	0.0161	0.0261	0.0783
2.468	0.0523	0.0414	0.1134
				2.476	0.0256	0.0202	0.049
2.484	0.0327	0.0326	0.041
				2.492	0.0265	0.0567	0.0393
2.5	0.0288	0.0386	0.0218

Table 1 be the 320th road 2.3s-2.5s near, in, absorption coefficient value a long way; SI is 0.8ms; Wherein two points of 2.38s and 2.388s are hydrocarbon zone position (labeling position in the table 1), can see, it is higher that its shortcut absorption value is compared regional value; And along with incident angle increases, middle road, absorption coefficient value a long way increase successively.Fig. 4 be by table 1 data obtain near, in, absorption curve figure a long way, can more intuitively react this conclusion.

Claims (5)

1. one kind based on the utilization of the Generalized S T conversion stratum elasticity absorption coefficient gas-oil detecting method of common-range gather not, and step comprises:

(1) earthquake-wave-exciting and write down the work area seismic event shakes the Data Processing flow process by the numbers and the seismic data of record is carried out the high-fidelity that relative amplitude keeps handles, and formation can directly be used for the road collection of amplitude after with the normal-moveout correction of offset distance mutation analysis;

(2) the offset distance numeric field data is transformed in the angle domain, obtains angular-trace gather, the sorting angle, carry out near, in, data stack a long way, form near at least, in, three superposition of data bodies a long way;

(3) the angle superposition of data after handling being carried out Generalized S T conversion, is frequency domain data with the time domain data-switching, and each road is done generalized S-transform and obtained S _i(t, f) f=f _b– f _eTo S _i(t f) does the Hilbert conversion, thereby obtains spectral amplitude PS _i(t, f);

$S(\mathrm{\&tau;},f)={\&Integral;}_{-\&infin;}^{\&infin;}{g}_f(t-\mathrm{\&tau;})h\left(t\right)\exp (-i2\mathrm{\&pi;}{f}_0\mathrm{ft})\mathrm{dt}$

Wherein $g_f\left(t\right)=A\left|f\right|\mathrm{Exp}(-\mathrm{\&alpha;}{(\mathrm{Ft}-\mathrm{\&beta;})}^2)$

A is the amplitude of basic small echo, and α is the energy attenuation rate, and β is the energy delay time, and t is the time, and τ is displacement, and f is a frequency, f ₀Be the video frequency of basic small echo, below all identical;

(4) confirm the low-and high-frequency and the boundary frequency f of zone of interest through experimental analysis _c, and do following calculating, can obtain the absorption coefficient (t) in each road;

$S_b\left(t\right)=\underset{k=b}{\overset{c}{\mathrm{\&Sigma;}}}{\mathrm{PS}}_i(t,f_k)$

$S_h\left(t\right)=\underset{k=c+1}{\overset{e}{\mathrm{\&Sigma;}}}{\mathrm{PS}}_i(t,f_k)$

$\mathrm{\&alpha;}\left(t\right)=\ln \frac{S_b\left(t\right)}{S_h\left(t\right)}$

Wherein, f _bBe low-frequency minimum, f _eBe high frequency limit, S _b(t) be low frequency energy, S _h(t) be high-frequency energy;

(5) absorption coefficient that different angles superposition of data body is calculated carries out normalization to be handled;

(6) result who the different angles superposition of data is calculated compares analysis, thus the potential zone of identification oil gas.

2. a kind of utilization based on Generalized S T conversion according to claim 1 is the stratum elasticity absorption coefficient gas-oil detecting method of common-range gather not, it is characterized in that, said step 2 forms four data stacks.

3. a kind of utilization based on Generalized S T conversion according to claim 1 is the stratum elasticity absorption coefficient gas-oil detecting method of common-range gather not, it is characterized in that, said step 2 forms five data stacks.

4. a kind of utilization based on Generalized S T conversion according to claim 1 is the stratum elasticity absorption coefficient gas-oil detecting method of common-range gather not; It is characterized in that; Numerical value normalization described in the said step 5 is handled; Be that its numerical value is normalized between 0 to 1, wherein absorb strong more near 1 representative more.

5. a kind of utilization based on Generalized S T conversion according to claim 1 is the stratum elasticity absorption coefficient gas-oil detecting method of common-range gather not; It is characterized in that; The result who in the said step 6 the different angles superposition of data is calculated compares analysis; Discrimination standard is: should there be obvious attenuation by absorption character in hydrocarbon zone in the shortcut data volume, and the absorption coefficient that promptly calculates is bigger, according to middle road, data a long way; Further strengthen along with incident angle increases absorbent properties, the attenuation properties of data reaches the strongest a long way; Differentiate with this, eliminate the false and retain the true, identification potential hydrocarbon zone.

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