CN109100796A

CN109100796A - A kind of gas hydrates seismic data processing technique and device

Info

Publication number: CN109100796A
Application number: CN201810607785.7A
Authority: CN
Inventors: 张峰; 范文豪; 李向阳; 钱忠平; 宋建军; 陈海峰
Original assignee: China University of Petroleum Beijing; BGP Inc; China Petroleum and Natural Gas Co Ltd
Current assignee: China University of Petroleum Beijing; BGP Inc; China Petroleum and Natural Gas Co Ltd
Priority date: 2018-06-13
Filing date: 2018-06-13
Publication date: 2018-12-28

Abstract

The application provides a kind of gas hydrates seismic data processing technique and device.The described method includes: being fitted using hydrate reservoir rock physics modeling method to sample data according to the log data in hydrate exploration area, Target Modeling method is obtained；Using the wedge-shaped body Model of Target Modeling method building hydrate, the forward modeling of seismic data is carried out according to wedge-shaped body Model, obtains synthetic seismogram；According to synthetic seismogram, free gas evaluation criterion, the saturation degree Thickness Evaluation standard of gas hydrates are constructed；The actual seismic data for obtaining the target area in hydrate exploration area are composed according to actual seismic data acquisition actual amplitude；According to actual amplitude spectrum, free gas evaluation criterion, saturation degree Thickness Evaluation standard, the hydrate characteristic information of target area is determined.Using embodiment each in the application, solves same hydrate reservoir petrophysical model in the adaptability problem in different exploratory areas, improve the accuracy of the seismic data process of gas hydrates.

Description

A kind of gas hydrates seismic data processing technique and device

Technical field

The application belongs to technical field of geophysical exploration more particularly to a kind of gas hydrates seismic data process side Method and device.

Background technique

The seismic prospecting of conventional gas hydrate is by Bottom-simulating reflection (BSR, Bottom Simulating Reflector) As the mark of hydrate identification, but the information such as relative hydropathic object saturation degree can not be obtained using BSR merely.The prior art In, when explanation is distributed more complicated heterogeneity hydrate reservoir, for gas hydrates reservoir thickness, saturation degree, it is There are biggish uncertainties for the no description that there are the physical property characteristics such as free gas-bearing formation.Therefore, in gas hydrates seismic data In explanation, the quantitatively or semi-quantitatively description of hydrate reservoir physical property characteristic is an essential technology.

Currently, in the processing of gas hydrates seismic data, usually using EFFECTIVE MEDIUM THEORY for hydrate Reservoir characteristic carries out rock physics forward simulation and carries out the explanation of gas hydrates seismic data, still, single rock physics Model has different applicable elements.In addition, the prior art only considered when analyzing the thickness and saturation degree of hydrate formation The relatively thin situation of hydrate layer, the exploratory area thicker for hydrate layer carry out earthquake in the hydrate layer to different thickness When spectral factorization, used standard frequency will will appear error.The above method is likely to lead to the physical property of gas hydrates The inaccuracy of feature description, influences the accuracy of gas hydrates seismic data process.Therefore, needing one kind in the industry can fit Hydrate reservoir physical property characteristic for different geological conditions describes, and further increases the accuracy of hydrate seismic data process Embodiment.

Summary of the invention

The application is designed to provide a kind of gas hydrates seismic data processing technique and device, solves same water Object reservoir rock physical model is closed in the adaptability problem in different exploratory areas, improves the seismic data process of gas hydrates Accuracy.

On the one hand this application provides a kind of gas hydrates seismic data processing techniques, comprising:

According to the log data in hydrate exploration area, using hydrate reservoir rock physics modeling method to sample data into Row fitting, obtains Target Modeling method；

Earthquake number is carried out using the wedge-shaped body Model of Target Modeling method building hydrate, and according to the wedge-shaped body Model According to forward modeling, obtain synthetic seismogram, the wedge-shaped body Model includes earth formation and the stratum of gas hydrates reservoir Corresponding speed, density information；

According to the synthetic seismogram, free gas evaluation criterion, the saturation degree Thickness Evaluation of gas hydrates are constructed Standard；

The actual seismic data for obtaining the target area in the hydrate exploration area, according to the actual seismic data acquisition Actual amplitude spectrum；

According to actual amplitude spectrum, the free gas evaluation criterion, the saturation degree Thickness Evaluation standard, determine described in The hydrate characteristic information of target area.

Further, in another embodiment of the method, the wedge-shaped body Model includes free gas wedge mould Type, without the wedge-shaped body Model of free gas；

Correspondingly, the construction method of the free gas evaluation criterion includes:

There are the first peak-to-valley ratio and the nothing of the corresponding synthetic seismogram of the wedge-shaped body Model of free gas described in obtaining respectively Second peak-to-valley ratio of the corresponding synthetic seismogram of the wedge-shaped body Model of free gas；

According to first peak-to-valley ratio and second peak-to-valley ratio, the free gas evaluation criterion is constructed.

Further, in another embodiment of the method, the free gas evaluation criterion of the building includes:

If the ratio of first peak-to-valley ratio and second peak-to-valley ratio is more than or equal to second peak-to-valley ratio, institute is judged Whether the peak-to-valley ratio for stating target area is more than or equal to the ratio of first peak-to-valley ratio Yu second peak-to-valley ratio；

If judging, the peak-to-valley ratio of the target area is more than or equal to the ratio of first peak-to-valley ratio and second peak-to-valley ratio Value, it is determined that the gas hydrates layer of the target area includes free gas；

If judging, the peak-to-valley ratio of the target area is less than the ratio of first peak-to-valley ratio and second peak-to-valley ratio, Determine that the gas hydrates layer of the target area does not include free gas.

Further, in another embodiment of the method, the free gas evaluation criterion includes:

If the ratio of first peak-to-valley ratio and second peak-to-valley ratio is less than second peak-to-valley ratio, the water is judged Whether the thickness for closing the hydrate layer of object exploration area is more than or equal to preset threshold；

If judging, the thickness of the hydrate layer in the hydrate exploration area is more than or equal to the preset threshold, when the mesh When marking the peak-to-valley ratio in region more than or equal to first peak-to-valley ratio, determine that the gas hydrates layer of the target area includes trip From gas, when the peak-to-valley ratio of the target area is less than first peak-to-valley ratio, the natural gas hydration of the target area is determined Nitride layer does not include free gas；

If judging, the thickness of the hydrate layer in the hydrate exploration area is less than the preset threshold, when the target area When the peak-to-valley ratio in domain is greater than second peak-to-valley ratio, determine that the gas hydrates layer of the target area includes free gas, when When the peak-to-valley ratio of the target area is less than or equal to second peak-to-valley ratio, the gas hydrates layer of the target area is determined Not comprising free gas.

Further, in another embodiment of the method, the construction method of the saturation thickness evaluation criterion includes:

Fourier transformation is carried out to the synthetic seismogram, obtains the corresponding amplitude spectrum of the synthetic seismogram, from The corresponding original spectral line of target frequency is extracted in the amplitude spectrum；

Using the seismic data in the hydrate exploration area in the pre-determined distance of well, school is carried out to the original spectral line Just, correction spectral line is obtained；

According to the correction spectral line, reference amplitude is determined, and according to the reference amplitude, the correction spectral line, the water The log data for closing object exploration area, constructs the saturation degree Thickness Evaluation standard.

Further, in another embodiment of the method, the saturation degree Thickness Evaluation standard of the building includes:

If the amplitude of the correction spectral line is greater than the reference amplitude value, it is determined that saturation degree is greater than default saturation degree, Thickness is greater than preset thickness；

If the amplitude of the correction spectral line is less than the reference amplitude value, the saturation in the hydrate exploration area is judged Degree and the variation degree of thickness horizontally；

If the variation degree of the saturation degree horizontally is greater than the variation degree of the thickness horizontally, it is determined that full It is less than the default saturation degree with degree, thickness is greater than the preset thickness；

If the variation degree of the saturation degree horizontally is less than the variation degree of the thickness horizontally, it is determined that full It is greater than the default saturation degree with degree, thickness is less than the preset thickness.

Further, described that the original spectral line is corrected in another embodiment of the method, it is corrected Spectral line, comprising:

According to the seismic data in the pre-determined distance of well in the hydrate exploration area, it is corresponding to extract the target frequency Practical spectral line, and obtain the actual (real) thickness of hydrate layer, practical saturation degree in the hydrate exploration area；

Obtain the average amplitude value of the practical spectral line；

The original spectral line is corrected according to the average amplitude value, the actual (real) thickness, practical saturation degree, is obtained The correction spectral line.

Further, in another embodiment of the method, the method also includes:

According to the hydrate characteristic information of the target area, the hydrate is constructed using the Target Modeling method and is surveyed The rate pattern in exploratory area；

According to the rate pattern, the zero-offset earthquake record of the target area is obtained；

The main wave character of the zero-offset earthquake record and the actual shifts section of the target area is carried out Matching, determines whether the hydrate characteristic information of the target area is accurate.

On the other hand, this application provides a kind of gas hydrates seismic data process devices, comprising:

Modeling method determining module utilizes hydrate reservoir rock object for the log data according to hydrate exploration area Reason modeling method is fitted sample data, obtains Target Modeling method；

Model building module, for the wedge-shaped body Model using Target Modeling method building hydrate, and according to the wedge Shape body Model carries out the forward modeling of seismic data, obtains synthetic seismogram, and the wedge-shaped body Model includes gas hydrates storage The corresponding speed of earth formation and stratum of layer, density information；

Evaluation criterion determining module, for according to the synthetic seismogram, the free gas for constructing gas hydrates to be commented Price card standard, saturation degree Thickness Evaluation standard；

Actual seismic data processing module, the actual seismic number of the target area for obtaining the hydrate exploration area According to according to actual seismic data acquisition actual amplitude spectrum；

Characteristic information determining module, for according to actual amplitude spectrum, the free gas evaluation criterion, the saturation degree Thickness Evaluation standard determines the hydrate characteristic information of the target area.

In another aspect, present invention also provides a kind of gas hydrates earthquake data processing systems, comprising: processor with And the memory for storage processor executable instruction, the processor realize above-mentioned natural gas hydration when executing described instruction Object seismic data processing technique.

Gas hydrates seismic data processing technique and device provided by the present application, according to the reality in hydrate exploration area Log data determines the Target Modeling method for being suitble to entire hydrate exploration area.It is constructed according to determining Target Modeling method It is corresponding synthetically to obtain different wedge-shaped body Models using seismic data forward modeling for the wedge-shaped body Model of gas hydrates reservoir Shake record.The free gas evaluation criterion of gas hydrates is constructed in synthetic seismogram based on acquisition, saturation degree thickness is commented Price card is quasi-.When the physical property characteristic for carrying out hydrate to target area is analyzed, the free gas evaluation criterion of building can be combined, satisfied The amplitude spectrum of the seismic data of target area is analyzed with degree Thickness Evaluation standard, determines that the hydrate of target area is special Reference breath.The hydrate reservoir petrophysical model i.e. wedge that the Target Modeling method selected in the embodiment of the present application constructs Model solves same hydrate reservoir petrophysical model in the adaptability in different exploratory areas to the more adaptable of target area Problem improves the accuracy of the seismic data process of gas hydrates.

Detailed description of the invention

In order to illustrate the technical solutions in the embodiments of the present application or in the prior art more clearly, to embodiment or will show below There is attached drawing needed in technical description to be briefly described, it should be apparent that, the accompanying drawings in the following description is only this The some embodiments recorded in application, for those of ordinary skill in the art, in the premise of not making the creative labor property Under, it is also possible to obtain other drawings based on these drawings.

Fig. 1 is a kind of method flow of gas hydrates seismic data processing technique one embodiment provided by the present application Schematic diagram；

Fig. 2 (a) -2 (d) is the signal of rock physics modeling method fitting hydrate sample data in the embodiment of the present application Figure；

Fig. 3 (a) -3 (d) is in the embodiment of the present application without the corresponding synthetic seismogram of the wedge-shaped body Model of free gas；

Fig. 4 (a) -4 (d) is that have the corresponding synthetic seismogram of the wedge-shaped body Model of free gas in the embodiment of the present application；

Fig. 5 (a) -5 (d) is in the embodiment of the present application without the corresponding amplitude spectrum of the wedge-shaped body Model of free gas；

Fig. 6 (a) -6 (b) is the correction spectral line of the target frequency of wedge model extraction in the embodiment of the present application；

Fig. 7 is the seismic profile schematic diagram of hydrate target area in the embodiment of the present application；

Fig. 8 (a) -8 (d) is the seismic profile of target area and its corresponding practical spectral line signal in the embodiment of the present application Figure；

Fig. 9 (a) -9 (d) is the seismic profile of target area and its corresponding practical spectral line in another embodiment of the application Schematic diagram；

Figure 10 is the actual shifts diagrammatic cross-section in the application one embodiment；

Figure 11 is the whole district's speed mould obtained in the application one embodiment using Target Modeling method combination log data Type schematic diagram；

Figure 12 is the earthquake record schematic diagram that rate pattern synthesizes in the embodiment of the present application；

Figure 13 is that the modular structure of gas hydrates seismic data process device one embodiment provided by the present application is shown It is intended to；

Figure 14 is that a kind of modular structure of gas hydrates earthquake data processing system embodiment provided by the present application is shown It is intended to.

Specific embodiment

In order to make those skilled in the art better understand the technical solutions in the application, below in conjunction with the application reality The attached drawing in example is applied, the technical scheme in the embodiment of the application is clearly and completely described, it is clear that described implementation Example is merely a part but not all of the embodiments of the present application.Based on the embodiment in the application, this field is common The application protection all should belong in technical staff's every other embodiment obtained without creative efforts Range.

Gas hydrates are distributed across in the permafrost of halmeic deposit or land-based area, are forced down by natural gas and water in height The crystalline material of the class ice-like formed under the conditions of temperature.Because of its appearance as ice and also meet fire be incendivity, so also referred to as " combustible ice " or " solid gas " and " gas ice ".In the seismic data of gas hydrates is explained, need to obtain natural gas The quantitative and semi-quantitative of hydrate reservoir physical property characteristic describes, and such as: gas hydrates reservoir thickness, whether there is saturation degree Free gas etc..

The embodiment of the present application proposes a kind of gas hydrates seismic data processing technique, the survey according to hydrate detecting area Well data, by determining the evaluation criterion of hydrate physical property characteristic for rock physics modeling method and seismic forward simulation method. According to determining evaluation criterion, the amplitude spectrum of actual seismic data is analyzed, determines the natural gas hydration of target area The physical property characteristic of object.The hydrate reservoir physical property characteristic description that can be adapted for different geological conditions, improves hydrate earthquake The accuracy of data processing.

Specifically, Fig. 1 is a kind of gas hydrates seismic data processing technique one embodiment provided by the present application Method flow schematic diagram, gas hydrates seismic data processing technique provided by the present application include:

S1, according to the log data in hydrate exploration area, using hydrate reservoir rock physics modeling method to sample number According to being fitted, Target Modeling method is obtained.

The application one embodiment can be according to lithology that the log data of hydrate detecting area provides, porosity, equivalent The information such as pressure, acoustic speed and hydrate concentration are utilized respectively a variety of hydrate reservoir rock physics modeling methods to sample Notebook data is fitted, and selects the hydrate reservoir rock physics modeling method high with actual sample data fitting depth as mesh Mark modeling method.Hydrate reservoir rock physics modeling method can establish out the geologic structure of hydrate layer as may include ground The information such as layer distribution, speed, density.Hydrate reservoir rock physics modeling method may include: three-phase weighted equation modeling side Method, Helgerud EFFECTIVE MEDIUM THEORY modeling method, the modeling of Hashin-Shtrikman (elasticity modulus) bounding theory of modification Method, three-phase Biot equation Modeling method etc..Some sample datas, sample data can be chosen in hydrate exploration area in advance It may include the information such as lithology, porosity, equivalent pressure, acoustic speed and hydrate concentration.Utilize above-mentioned hydrate reservoir Rock physics modeling method is fitted practical hydrate sample data, calculates the modeling of these four hydrate reservoir rock physics Residual sum of squares (RSS) between the speed that method obtains-hydrate concentration curve and actual sample point, by corresponding residual sum of squares (RSS) The smallest hydrate reservoir rock physics modeling method is determined as being suitble to the gas hydrates reservoir in this hydrate exploration area Rock physics modeling method, i.e. Target Modeling method.

Above-mentioned four kinds of rock physics modeling methods can refer to following the description, the three-phase weighted equation modeling side of hydrate layer Method may be expressed as:

In above formula, V_pIt can indicate the hydrate formation velocity of longitudinal wave that three-phase weighted equation calculates；V_p1It can indicate Wood The velocity of longitudinal wave that equation calculates；V_p2It can indicate the velocity of longitudinal wave that time-average equation calculates；W can indicate weighted factor；n It can indicate the constant that simulation diagenesis changes with hydrate concentration；S can indicate hydrate concentration；φ can be indicated Porosity.

The Helgerud EFFECTIVE MEDIUM THEORY modeling method of hydrate layer may be expressed as:

G_Sat=G_Dry (3)

In above formula, φ can indicate porosity；K_SatWith can indicating the hydrate that Helgerud EFFECTIVE MEDIUM THEORY calculates Layer bulk modulus；K_fIt can indicate the bulk modulus of pore-fluid；K_DryAnd G_DryIt can indicate to be mentioned with Dvorkin et al. (1999) The dry marine sediment elasticity modulus that model out is calculated；K can indicate solid phase bulk modulus, be hydrated using considering The Hill average computation for each mineral that object influences obtains.

The Hashin-Shtrikman bounding theory modeling method of hydrate layer modification may be expressed as:

In above formula, S_hIt can indicate that hydrate concentration, α can indicate that the microstructure of simulating hydrate is filling hole Or the parameter of particle contact, K_hsAnd G_hsIt can indicate to be obtained by the Reuss average computation of hydrate and aquifer water-bearing stratum, K_hmWith G_hmIt can indicate to be obtained by the Reuss average computation of hydrate and mineralogical composition, K_hydAnd G_hydIt is that hydrate concentration is big respectively The hydrate formation bulk modulus and shearing mould that the Hashin-Shtrikman bounding theory modified when parameter alpha is calculated Amount.When hydrate concentration is less than parameter alpha, the concrete moduli of hydrate formation is equal to K_hsAnd G_hs；When hydrate concentration is big When parameter alpha, the concrete moduli of hydrate formation is equal to K_hydAnd G_hyd。

The three-phase Biot equation Modeling method of hydrate layer may be expressed as:

In above formula, ρ_bIt can indicate bulk density, R_ijAnd μ_ijIt can indicate to influence the matrix element of whole p-and s-wave velocity, V_p、V_sIt respectively indicates.

S2, carry out ground using the wedge-shaped body Model of Target Modeling method building hydrate, and according to the wedge-shaped body Model Shake data forward modeling, obtain synthetic seismogram, the wedge-shaped body Model include gas hydrates reservoir earth formation and The corresponding speed in stratum, density information.

It determines after being suitble to the Target Modeling method of hydrate detecting area, can use Target Modeling method and construct hydration The wedge-shaped body Model of object, wedge-shaped body Model may include gas hydrates reservoir earth formation and each stratum speed and Density information etc..It can use formation velocity-hydrate concentration that the Target Modeling method determined obtains hydrate reservoir Relationship can calculate the volume density of hydrate reservoir using following formula (7).Utilize the stratum speed of the hydrate reservoir of acquisition Degree and volume density, (such as: can be according to gal in conjunction with thickness, hydrate concentration of the hydrate reservoir obtained in log data etc. The Low value anomaly of horse log determines sandstone layer range, according to the high-value sector of acoustic logging and Resistivity log It determines hydrate sandstone layer thickness, Archie formula can use to Resistivity log, hydrate concentration is calculated, Or hydrate concentration is estimated by Interstitial Water chlorinty), the wedge-shaped body Model of different hydrate concentrations can be constructed.

ρ_b=φ [S_hρ_h+(1-S_h)ρ_w]+(1-φ)ρ_s (7)

In above formula, ρ_bIt can indicate volume density, φ can indicate porosity, S_hIt can indicate hydrate concentration, ρ_hIt can be with Indicate hydrate density, ρ_wIt can indicate the density of water, ρ_sIt can indicate the density of solid phase in skeleton.

In the application one embodiment, the wedge-shaped body Model of hydrate may include have the wedge-shaped body Model of free gas (such as: on Layer is full water layer, and intermediate wedge layer is containing hydrate layer, and lower layer is containing free gas-bearing formation) and without the wedge-shaped body Model of free gas (such as: on Layer is full water layer, and intermediate wedge layer is containing hydrate layer, and lower layer is full water layer).Certainly, the specific earth formation of wedge-shaped body Model It can also include other forms, such as: upper layer is saturation water layer, and intermediate and lower layer is letter hydrate layer, and the application does not make specifically It limits.The construction method of body Model wedge-shaped for no free gas can refer to following process: the clear model intermediate hydration first The corresponding hydrate concentration of object wedge shaped layer is how many, is then calculated to intermediate hydrate wedge shaped layer with Target Modeling method The hydrate formation speed and density of corresponding given hydrate concentration, the speed and density of full water layer can be provided by well logging up and down Material (acoustic logging and density log curve) or Target Modeling method (the case where corresponding zero hydrate concentration) provide, most Afterwards by changing the hydrate concentration of intermediate hydration object wedge shaped layer, and repeat the above steps, the different hydrations of available correspondence In the case of object saturation degree without the wedge-shaped body Model of free gas.

For there is the construction method of the wedge-shaped body Model of free gas that can refer to following process: its building process and no free gas Wedge-shaped body Model is almost the same, and difference is the speed and density that have free gas wedge model lower part containing free gas-bearing formation by logging well (free gas petrophysical model must go on a tour for data (acoustic logging and density log curve) or free gas petrophysical model From the relationship between the free gas saturation of gas formation velocity-, the rough trip in hydrate exploration area can be determined according to previous From Gas content, then fixed free gas saturation obtains corresponding free gas formation velocity and density) it provides.

Wedge-shaped body Model contains the speed and density information of each layer (full water layer contains hydrate layer and containing free gas-bearing formation), Can be with the reflection coefficient at interface between calculated hydration nitride layer and upper and lower level using these information, then carrying out convolution forward modeling with wavelet can To obtain the corresponding synthetic seismogram of the wedge-shaped body Model of difference in the case of different hydrate concentrations, such as: can obtain above-mentioned There is the corresponding synthetic seismogram of the wedge-shaped body Model of free gas synthetic seismogram corresponding with the wedge-shaped body Model of no free gas.It can Reflection coefficient and seismic wavelet are carried out convolution forward modeling with reference to following formula (8), synthetic seismogram is obtained.

S (t)=b (t) * ξ (t) (8)

In above formula, s (t) can indicate synthetic seismogram, and b (t) can indicate that seismic wavelet, ξ (t) can indicate to reflect Coefficient sequence.

S3, according to the synthetic seismogram, construct the free gas evaluation criterion of gas hydrates, saturation degree thickness is commented Price card is quasi-.

According to synthetic seismogram, the corresponding amplitude spectrum of the wedge-shaped body Model of difference can be obtained, in conjunction in wedge-shaped body Model Earth formation and corresponding amplitude spectrum can construct the free gas evaluation criterion and saturation degree Thickness Evaluation of gas hydrates Standard.Such as: according to the earthquake record for having the wedge-shaped body Model of free gas, the corresponding vibration of the wedge-shaped body Model of free gas can have been obtained Width spectrum, according to the gas hydrates reservoir for thering is the wedge-shaped body Model of free gas corresponding amplitude spectrum to can analyze out free gas The features such as amplitude, saturation degree, thickness, further constructs free gas evaluation criterion and saturation degree Thickness Evaluation standard.Such as: if logical Crossing analysis has the amplitude spectrum of the wedge-shaped body Model of free gas and the amplitude spectrum without the wedge-shaped body Model of free gas, determines free gas The amplitude ratio of gas hydrates reservoir is greater than K, and amplitude ratio can be greater than to K as the evaluation criterion for having free gas.

S4, obtain the hydrate exploration area target area actual seismic data, according to the actual seismic data Obtain actual amplitude spectrum.

It, can be from the hydration after the free gas evaluation criterion and saturation degree Thickness Evaluation standard that construct gas hydrates Target area is chosen in object exploration area, and target area can be one or more, can choose different number, no according to actual needs With the target area of position.According to the actual seismic data in the available target area such as log data, seismic exploration data, The corresponding actual amplitude spectrum of actual seismic data may further be obtained.

S5, according to actual amplitude spectrum, the free gas evaluation criterion, the saturation degree Thickness Evaluation standard, determine The hydrate characteristic information of the target area.

It can be compared by free gas evaluation criterion, the saturation degree evaluation criterion that actual amplitude is composed and constructed, really The hydrate characteristic information of target area is made, hydrate characteristic information may include whether containing free gas, hydrate reservoir Thickness, saturation degree etc..Such as: if pointing out in the free gas evaluation criterion of building, amplitude ratio is greater than K, it is determined that comprising free Gas.The amplitude ratio obtained in target area can be composed according to actual amplitude, further determine that out whether target area includes free Gas.

Gas hydrates seismic data processing technique provided by the embodiments of the present application, according to the reality in hydrate exploration area Log data determines the Target Modeling method for being suitble to entire hydrate exploration area.It is constructed according to determining Target Modeling method It is corresponding synthetically to obtain different wedge-shaped body Models using seismic data forward modeling for the wedge-shaped body Model of gas hydrates reservoir Shake record.The free gas evaluation criterion of gas hydrates is constructed in synthetic seismogram based on acquisition, saturation degree thickness is commented Price card is quasi-.When the physical property characteristic for carrying out hydrate to target area is analyzed, the free gas evaluation criterion of building can be combined, satisfied The amplitude spectrum of the seismic data of target area is analyzed with degree Thickness Evaluation standard, determines that the hydrate of target area is special Reference breath.The hydrate reservoir petrophysical model i.e. wedge that the Target Modeling method selected in the embodiment of the present application constructs Model solves same hydrate reservoir petrophysical model in the adaptability in different exploratory areas to the more adaptable of target area Problem improves the accuracy of the seismic data process of gas hydrates.

On the basis of the above embodiments, the wedge-shaped body Model includes the wedge-shaped body Model of free gas, without free gas wedge Shape body Model；

The concrete form of wedge-shaped body Model can consistent with above-described embodiment details are not described herein again.Acquisition has free gas wedge-shaped After the composite traces of body Model and composite traces without the wedge-shaped body Model of free gas, trip can be calculated separately according to formula (9) The corresponding first peak-to-valley ratio r of composite traces from the wedge-shaped body Model of gas₁, the composite traces of no wedge-shaped body Model of free gas is corresponding Second peak-to-valley ratio r₂.It can be constructed according to by the first peak-to-valley ratio of analysis and the second peak-to-valley ratio and corresponding wedge-shaped body Model Free gas evaluation criterion.Such as: if having the composite traces of the wedge-shaped body Model of free gas and without free gas wedge mould by comparison The composite traces of type, when peak-to-valley ratio is greater than the second peak-to-valley ratio less than the first peak-to-valley ratio, corresponding wedge-shaped body Model has trip for discovery From gas, then peak-to-valley ratio can be greater than the second peak-to-valley ratio as the evaluation criterion for having free gas less than the first peak-to-valley ratio.Certainly, root According to real data, the free gas evaluation criterion in suitable hydrate exploration area can be constructed, the embodiment of the present application does not limit specifically It is fixed.

R=A_c/A_t (9)

In above formula, A_cIt can indicate the amplitude of hydrate layer bottom reflection signals wave crest, A_tIt can indicate hydrate layer bottom The amplitude of portion's reflection signal trough.

The embodiment of the present application constructs different hydrate reservoir petrophysical models using selected Target Modeling method After i.e. wedge-shaped body Model, the corresponding synthesis earthquake of the wedge-shaped body Model of difference is obtained by carrying out forward modeling to different wedge-shaped body Models Record further obtains the corresponding peak-to-valley ratio of the wedge-shaped body Model of difference.By comparing the corresponding peak-to-valley ratio of the wedge-shaped body Model of difference, The free gas evaluation criterion in suitable hydrate exploration area is constructed, the description for post-hydration object physical property characteristic provides theoretical base Plinth.

On the basis of the above embodiments, in the application one embodiment, the free gas evaluation criterion of the building can be with Include:

Specifically, in the first peak-to-valley ratio r₁With the second peak-to-valley ratio r₂Ratio be more than or equal to the second peak-to-valley ratio r₂That is (r₁/r₂) ≥r₂In the case where, if the corresponding peak-to-valley ratio of BSR (Bottom Simulating Reflector) is on actual seismic section Whether the corresponding peak-to-valley ratio r of the seismic data of target area is more than or equal to the ratio of the first peak-to-valley ratio Yu the second peak-to-valley ratio.If r >= (r₁/r₂), it is determined that there is free gas under the hydrate layer of target area；If r < (r₁/r₂), it is determined that the hydrate of target area Without free gas under layer.

In the application one embodiment, the free gas evaluation criterion includes:

If judging, the thickness of the hydrate layer in the hydrate exploration area is less than the preset threshold, when the target area When the peak-to-valley ratio in domain is more than or equal to first peak valley and the ratio of second peak-to-valley ratio, the natural of the target area is determined Gas hydrate layer includes free gas, when the peak-to-valley ratio of the target area is less than first peak valley and second peak-to-valley ratio When ratio, determine that the gas hydrates layer of the target area does not include free gas.

Specifically, in the first peak-to-valley ratio r₁With the second peak-to-valley ratio r₂Ratio less than the second peak-to-valley ratio r₂That is (r₁/r₂) < r₂ In the case where, judge that showing whether hydrate exploration area hydrate layer is thicker by log data (utilizes hydrate exploration area if Well in the Low value anomaly of GR logging curve determine sandstone layer range, the high level of acoustic logging and Resistivity log Exception can determine hydrate sandstone layer thickness) i.e. whether the thickness of the hydrate layer in hydrate exploration area be more than or equal to default threshold When value.If the thickness of hydrate exploration area hydrate layer is more than or equal to preset threshold, the seismic data pair of target area is judged Whether the peak-to-valley ratio r answered is more than or equal to the first peak-to-valley ratio r₁, as r >=r₁When, it is determined that there is trip under the hydrate layer in target complex region From gas, as r < r₁, it is determined that without free gas under the hydrate layer of target area.If obtaining hydrate exploration area by log data Hydrate layer is relatively thin, i.e., when the thickness in hydrate exploration area is less than preset threshold, then judges that the seismic data of target area is corresponding Peak-to-valley ratio r whether be more than or equal to the second peak-to-valley ratio r₂, as r > r₂When, it is determined that have under the hydrate layer of target area free Gas, as r≤r₂, it is determined that without free gas under the hydrate layer of target area.

It should be noted that judging that the specific value of the whether thicker preset threshold of hydrate layer can be in above-described embodiment It is configured according to actual needs, the embodiment of the present application is not especially limited.As: hydrate thickness be greater than 100m, can be with Think that hydrate layer is thicker, 100m can be set by preset threshold.

The peak-to-valley ratio that the embodiment of the present application provides a kind of wedge-shaped body Models of utilization difference constructs free gas evaluation criterion Specific method, in hydrate exploration area target area carry out hydrate physical property characteristic description when, can be according to structure The free gas evaluation criterion built out judges whether the hydrate reservoir of target area includes free gas.It is free to realize target area The determination of gas information provides accurate data basis for gas hydrates seismic interpretation.

On the basis of the above embodiments, in the application one embodiment, the building side of the saturation thickness evaluation criterion Method may include:

Specifically, formula (10) can be used, Fourier transformation is carried out to the corresponding synthetic seismogram of wedge-shaped body Model, Corresponding amplitude spectrum is obtained, the horizontal axis of amplitude spectrum can be hydrate tapered layer thickness, and the longitudinal axis can be frequency.In the amplitude spectrum The a certain frequency of middle fixation and target frequency extract the original spectrum that the amplitude of corresponding target frequency changes with hydrate tapered layer thickness Line.Wherein the determination of target frequency can be using spectral line dullness in amplitude spectrum as principle.Such as: for having free gas under hydrate layer Have the wedge-shaped body Model of free gas, to the amplitude spectrum of its forward modeling result (i.e. synthetic seismogram), perform a scan, drafting is given Determine the spectral line that amplitude changes with hydrate tapered layer thickness under frequency, when the spectral line dullness drawn, corresponding frequency is to need The standard frequency f wanted₁；For under hydrate layer without free gas without the wedge-shaped body Model of free gas, do similar analysis and provide pair The standard frequency f answered₂。

After extracting the corresponding original spectral line of wedge-shaped body Model, using in seismic data, that is, hydrate exploration area of well Seismic data in the pre-determined distance of well.Some regional well locations are not in earthquake work area, but apart from one spacing of earthquake work area From place, the hydrate layer thickness and hydrate concentration information of interpretation of logging data in well are used at this time, needed using from well The nearest corresponding seismic data of seismic survey lines in position is the seismic data close to well.It should be noted that well and earthquake work area Distance must not be too far away, and information cannot reflect that the hydrate physical property on nearly well seismic profile is special in well apart from each other with earthquake work area Sign.The original spectral line extracted from wedge-shaped body Model is corrected using the seismic data close to well, obtains correction spectral line. Such as: the spectral line amplitude that can be extracted from the seismic data close to well, in conjunction with the corresponding hydrates thickness degree that is obtained from well and Hydrate concentration value can be used as standard value and correct original spectral line, is corrected to the amplitude of the original spectral line of extraction.

Reference amplitude A can be determined according to the correction spectral line after correction₀, according to reference amplitude A₀, correction spectral line, hydration The log data of object exploration area constructs the saturation degree Thickness Evaluation standard.Such as: it can be according to the well logging in hydrate exploration area Data obtain saturation degree, the thickness of practical hydrate reservoir.By actual saturation degree, thickness and the corresponding thickness of correction spectral line, Saturation degree compares, and obtains and is greater than in correction spectral line, is less than reference amplitude A₀Position at hydrate reservoir saturation degree, The information such as thickness, as saturation degree Thickness Evaluation standard.

Wherein, the setting of reference amplitude can be configured according to situations such as saturation degree, thickness of practical exploration area, this Shen Please embodiment be not especially limited.

In above formula, w_N=e^(-2πi)/N；X (k) is the discrete Fourier transform result of discrete signal x (j)；K represents X's (k) Various discrete point；X (j) is a discrete signal；J represents the various discrete point of x (j)；I indicate imaginary number, square etc. -1；N be from The length of scattered signal x (j), the i.e. discrete points of x (j)；w_NIt is a kind of expression symbol, indicates e^(-2πi)/N。

The embodiment of the present application is corresponding to the wedge-shaped body Model constructed using the seismic data in practical hydrate exploration area Amplitude spectrum is corrected, so that the original spectral line amplitude extracted is consistent with the spectral line amplitude magnitude that actual seismic data is extracted, and On the basis of correcting spectral line, saturation degree Thickness Evaluation standard is constructed, the accuracy of saturation degree Thickness Evaluation standard is improved, into The accuracy that one step improves hydrate concentration, thickness information determines.

On the basis of the above embodiments, in the application one embodiment, the saturation degree Thickness Evaluation standard of the building May include:

Specifically, reference amplitude A is selected on correction spectral line₀Afterwards, when the amplitude A of correction spectral line is greater than reference amplitude A₀ When, it is believed that corresponding is with higher hydrates saturation degree S_hWith larger thickness H, i.e. thickness is greater than preset thickness H, and saturation degree is big In default saturation degree S_h.Preset thickness H can correspond to the maximum gauge of wedge-shaped body Model intermediate hydration object wedge shaped layer, can be just Fixed thickness in spectral line (curve that amplitude changes with intermediate hydration object tapered layer thickness under different hydrate concentrations) is drilled to determine For preset thickness H, determine that corresponding hydrate concentration is higher hydrates saturation degree S by amplitude_h.For correction spectral line Amplitude A is less than reference amplitude A₀The case where, can be judged according to the log data in hydrate exploration area in region saturation degree and The variation degree horizontally of thickness.If saturation degree horizontally changes more acutely in hydrate exploration area, can recognize It is less than reference amplitude A for amplitude A₀Corresponding is lesser saturation degree S_hWith larger thickness H, i.e. saturation degree is less than default saturation Degree, thickness are greater than preset thickness.If thickness horizontally changes more acutely in hydrate exploration area, then it is assumed that amplitude A is small In reference amplitude A₀Corresponding is larger saturation degree and relatively small thickness, i.e. saturation degree is greater than default saturation degree, and thickness is less than default Thickness.

Can according to the above-mentioned saturation degree Thickness Evaluation standard determined, indicated in correction spectral line which situation belong to compared with The larger saturation degree of big thickness, which situation belong to the smaller saturation degree of larger thickness, which situation belongs to the larger saturation of relatively small thickness Degree.To target area saturation degree and thickness evaluate when, can be by the spectral line of the seismic data of target area and correction Spectral line and corresponding saturation degree Thickness Evaluation standard are compared, and determine the saturation degree and thickness of target area.

The hydrate reservoir rock that the embodiment of the present application selects utilization based on the actual seismic data in hydrate exploration area The amplitude spectrum that the wedge-shaped body Model that Method of Physical Modeling is established carries out after forward modeling is corrected, and according to the correction spectral line after correction The saturation degree Thickness Evaluation standard of hydrate physical property characteristic description is constructed, is the saturation of the subsequent hydrate reservoir to target area The description of degree and thickness provides accurate data basis.

On the basis of the above embodiments, described that the original spectral line is corrected in the application one embodiment, it obtains Spectral line must be corrected, may include:

Obtain the average amplitude value of the practical spectral line；

It specifically, can be from the seismic data (earthquake i.e. in hydrate exploration area in the pre-determined distance of well close to well Data) extract spectral line amplitude.Such as: if it is determined that the target frequency for having the wedge-shaped body Model of free gas be f₁, no free gas wedge The target frequency of shape body Model is f₂, then can according in hydrate exploration area close to well the corresponding amplitude spectrum of seismic data in Frequency f is extracted respectively₁、f₂Corresponding practical spectral line.It calculates separately and obtains target frequency f₁、f₂Corresponding practical spectral line is corresponding Average amplitude value, b₁And b₂, in conjunction with the corresponding hydrates thickness degree and hydrate concentration value obtained from well, can obtain The standard value for correcting spectral line, is corrected the amplitude of the original spectral line extracted from forward modeling amplitude spectrum.

Such as: if obtaining the thickness h of hydrate layer in the case of free gas by log data₁With saturation degree s₁, no free gas In the case of hydrate layer thickness h₂With saturation degree s₂.Calculating separately maximum gauge is h₁There is free gas forward modeling spectral line to exist h₁And s₁Under amplitude a₁, maximum gauge h₂Without free gas forward modeling spectral line in h₂And s₂Under amplitude a₂, maximum With a thickness of h₁Have free gas forward modeling spectral line in h₁And s₂Under amplitude a₃.Here with h₁And s₂It is due to usually corresponding Well data under hydrate layer without free gas is simultaneously few, and the nearest well in liftoff shake work area, which probably corresponds under hydrate layer, trip It the case where from gas, i.e., can only be to there is free gas wedge forward modeling spectral line to be corrected under hydrate layer.When practical application, H can be used₂、s₁Under amplitude to being Fourier within the scope of hydrate zone close to the seismic data containing free gas well Transformation.Because when doing Fourier transformation to wedge-shaped body Model synthetic seismogram, actually only intermediate hydration object wedge shaped layer It pushes up bottom and there is reflection.Will using in forward modeling amplitude spectrum frequency information and actual seismic data amplitudes spectrum in frequency information come into The description of row hydrate physical property characteristic, needs to keep the hypothesis of forward modeling spectrum analysis and real data spectrum analysis almost the same.Wedge mould When Fourier transformation is done in the synthetic seismogram of type, the window ranges of selection are that (range includes upper layer to entire wedge-shaped body Model Saturation water layer, the hydrate wedge shaped layer of middle layer, the full water layer of lower layer or containing free gas-bearing formation).The embodiment of the present application by pair Actual seismic data will do Fourier transformation and obtain amplitude spectrum and (will be hydrated to the signal included at least within the scope of hydrate zone The top bottom reflection of nitride layer, which is included, carries out Fourier transformation), amplitude spectrum is obtained, and extract corresponding target frequency f₁And f₂It is corresponding Spectral line, calculate separately target frequency f₁And f₂The average amplitude value b of corresponding spectral line₁And b₂, obtained in conjunction with above-described embodiment The actual (real) thickness of hydrate layer, practical saturation degree are corrected original spectral line in hydrate exploration area.Such as: having free gas wedge-shaped The corresponding f of body Model₁Spectral line can be by multiplied by b₁/a₁Complete correction；The no wedge-shaped body Model of free gas corresponds to f₂Spectral line can By multiplied by (b₂(a₂/a₃))/a₂Complete correction.

Based on the amplitude spectrum of the correction spectral line after correction, the saturation degree Thickness Evaluation standard of hydrate can be constructed, is had The construction method of body evaluation criterion can refer to above-described embodiment, and details are not described herein again.

The amplitude for the earthquake record that the embodiment of the present application obtains forward modeling using the actual seismic data in hydrate exploration area Spectrum is corrected, and improves the accuracy of the synthetic seismogram of forward modeling acquisition, is the physical property characteristic of subsequent gas hydrates Description provides accurate data basis.

On the basis of the above embodiments, in the application one embodiment, the method can also include:

Specifically, based on the above embodiment in physical property characteristic carried out to different hydrate target areas in each step retouch It states, obtains the hydrate characteristic information of target area water, built using the hydrate reservoir petrophysical model, that is, target preferably gone out Mould method, and combination log data establishes the rate pattern of the whole district.Rate pattern can be retouched according to hydrate layer physical property characteristic The result stated (whether there is or not free gas, hydrate layer thickness and hydrate concentration under hydrate layer, is provided using Target Modeling method Relationship between hydrate concentration and hydrate formation speed calculates the speed of different hydrate target areas, to establish Rate pattern.To speed and density model, (density model is calculated using volume density calculation formula or by density log curve Obtain) utilize convolution model, the zero-offset earthquake record of available synthesis.If synthesis zero-offset earthquake record with The main wave character of the actual shifts section of target area is almost the same, can verify in above-described embodiment to hydrate target The correctness of regional petrophysics characteristic evaluating result, that is, it is accurate for obtaining the hydrate characteristic information of big target area.

By verifying, can determine whether acquisition hydrate characteristic information is accurate in the embodiment of the present application, if verifying knot Fruit inaccuracy, can be adjusted Target Modeling method, free gas evaluation criterion, saturation degree Thickness Evaluation standard, to obtain More accurate hydrate characteristic information is obtained, the accuracy that gas hydrates seismic data process is dismissed is improved.

The technical solution of the embodiment of the present application is introduced below with reference to specific example:

(1) lithology, porosity, equivalent pressure, the sound wave speed provided according to the ridge Bu Laike hydrate exploration area log data Degree and the information such as hydrate concentration, respectively using three-phase weighted equation, Helgerud EFFECTIVE MEDIUM THEORY, modification The hydrate reservoirs rock physics modeling method such as Hashin-Shtrikman bounding theory and three-phase Biot equation is to practical hydration Object sample data is fitted (Fig. 1).Calculate velocity of longitudinal wave-water that these four hydrate reservoir rock physics modeling methods obtain The residual sum of squares (RSS) between object saturation curves and practical hydrate sample point is closed, by the corresponding the smallest hydrate of residual sum of squares (RSS) The rock physics modeling method i.e. target that reservoir rock Method of Physical Modeling is preferably suitable for exploratory area gas hydrates reservoir is built Mould method.

Fig. 2 (a) -2 (d) is the signal of rock physics modeling method fitting hydrate sample data in the embodiment of the present application Figure, Fig. 2 (a) are the schematic diagrames of Helgerud EFFECTIVE MEDIUM THEORY fitting hydrate sample data, and Fig. 2 (b) is the three-phase side Biot Journey is fitted hydrate sample data, and L1 indicates the description porosity that three-phase Biot equation uses with becoming smaller increase stiffness layer validity Parameter e=0, consolidation parameters a=40；L2 indicates to use e=0.12, a=40；L3 indicates to use e=1, a=40.Fig. 2 (c) It is the Hashin-Shtrikman edge fitting hydrate sample data schematic diagram of modification, Fig. 2 (d) is the fitting of three-phase weighted equation Hydrate sample data.By comparison, the velocity of longitudinal wave that Fig. 2 (d) is obtained-hydrate concentration curve and practical hydrate sample Residual sum of squares (RSS) between point is minimum, and the embodiment of the present application is by the Hashin-Shtrikman bounding theory hydrate reservoir of modification Rock physics modeling method is as Target Modeling method.

(2) using the rock physics modeling method (Fig. 2 (d)) of the suitable exploratory area hydrate reservoir preferably gone out in step (1) Calculate the speed and density of corresponding different hydrate concentrations.The hydrate storage provided by the log data in hydrate exploration area The prior informations such as thickness degree and hydrate concentration, it is thicker to obtain cloth outputting Lake ridge area hydrate reservoir, can achieve 280ms； And this area's hydrate concentration is lower, generally less than 30%.Establishing upper and lower level respectively accordingly is full water layer, and centre is hydrate Layer is full water layer without the wedge-shaped body Model a of free gas and upper layer, centre is hydrate layer, and lower layer is that free gas-bearing formation has trip Body Model b wedge-shaped from gas.And both models are obtained in different hydrate concentrations synthetically by convolution model Shake record.Fig. 3 (a) -3 (d) is in the embodiment of the present application without the corresponding synthetic seismogram of the wedge-shaped body Model of free gas, Fig. 3 (a) the wedge-shaped body Model upper and lower level in -3 (d) is full water layer, and centre is hydrate layer.The hydrate concentration of Fig. 3 (a) is The hydrate concentration that 0%, Fig. 3 (b) hydrate concentration is 10%, Fig. 3 (c) is that 20%, Fig. 3 (d) hydrate concentration is 30%.Fig. 4 (a) -4 (d) is that have the corresponding synthetic seismogram of the wedge-shaped body Model of free gas, Fig. 4 (a) -4 in the embodiment of the present application (d) the wedge-shaped body Model upper layer in is full water layer, and centre is hydrate layer, and lower layer is free gas-bearing formation.The hydrate of Fig. 4 (a) is full It is 0% with degree, the hydrate concentration that the gas saturation that dissociates is 17%, Fig. 4 (b) is 10%, and the gas saturation that dissociates is 17%, figure 4 (c) hydrate concentration is 20%, and the hydrate concentration that the gas saturation that dissociates is 17%, Fig. 4 (d) is 30%, free gas Saturation degree is 17%.

The forward modeling result (Fig. 4 (a) -4 (d)) that above-mentioned formula (9) calculates free gas wedge-shaped body Model b can be used Peak-to-valley ratio r₁It is 2.391, the peak-to-valley ratio r of no wedge-shaped body Model a forward modeling result (Fig. 3 (a) -3 (d)) of free gas₂It is 2.368, r₁/ r₂Equal to 1.01, (r₁/r₂) < r₂.Therefore, it is hydrated as the corresponding peak-to-valley ratio r >=2.391 of BSR on actual seismic section, at this There is free gas under nitride layer, as r < 2.391, without free gas under hydrate layer at this.The exploratory area hydrate layer is judged to establish Under whether there is or not the standards of free gas.

(3) Fig. 5 (a) -5 (d) is in the embodiment of the present application without the corresponding amplitude spectrum of the wedge-shaped body Model of free gas, Fig. 5 (a) -5 (d) upper and lower level without the wedge-shaped body Model of free gas in is full water layer, and centre is hydrate layer.The hydrate concentration of Fig. 5 (a) The hydrate that the hydrate concentration that hydrate concentration for 0%, Fig. 5 (b) is 10%, Fig. 5 (c) is 20%, Fig. 5 (d) is full It is 30% with degree.As shown in Fig. 5 (a) -5 (d), body Model a wedge-shaped for no free gas, the wedge used with a thickness of 70ms, Calculate the amplitude spectrum of its forward modeling result.Fig. 6 (a) -6 (b) is the target frequency of wedge model extraction in the embodiment of the present application Spectral line is corrected, Fig. 6 (a) indicates that upper and lower level is full water layer, and centre is the original spectrum without the wedge-shaped body Model of free gas of hydrate layer Line, obtained spectral line dullness are principle, and providing target frequency is 6Hz.The corresponding saturation degree of L1 is 30%, L2's in Fig. 6 (a) The saturation degree that the saturation degree that saturation degree is 20%, L3 is 10%, L4 is 0%.For there is the wedge-shaped body Model b of free gas, use Wedge is with a thickness of 280ms, and as shown in Fig. 6 (b), upper layer is full water layer, and centre is hydrate layer, and lower layer is having for free gas-bearing formation The wedge-shaped body Model of free gas is 1.8Hz using target frequency.The corresponding saturation degree of L1 is the corresponding saturation of 30%, L2 in Fig. 6 (b) It is the corresponding saturation degree of 10%, L4 is 0% that degree, which is the corresponding saturation degree of 20%, L3,, the free gas saturation of L1, L2, L3, L4 It is 17%.The amplitude of Fig. 6 (a) -6 (b) spectral line is all corrected with seismic data, and the seismic data pair close to well is utilized Spectral line amplitude under above two model is corrected, and corresponds to 1.8Hz's by the way that the wedge-shaped body Model b of free gas is calculated Original spectral line needs to complete to correct multiplied by 1324.5033；The original spectral line needs that the no wedge-shaped body Model a of free gas corresponds to 6Hz multiply Correction is completed with 115.942, shown in classification spectral line such as Fig. 6 (a) -6 (b) after finally obtained correction.

The correction spectral line of body Model a wedge-shaped for no free gas, selects amplitude 1.5 for benchmark amplitude, when the spectrum of forward modeling Line amplitude is greater than 1.5, it is believed that corresponding is the hydrate reservoir (hydrate with higher hydrates saturation degree and larger thickness Without free gas under layer).It is 2 for there is the reference amplitude of the choice of spectrum of the wedge-shaped body Model b of free gas, when the spectral line amplitude of forward modeling When value is greater than 2, it is believed that corresponding is the hydrate storage for being covered in free gas with higher hydrates saturation degree and larger thickness Layer.According to the ridge Bu Laike area well-log information, thus it is speculated that this area's hydrate concentration horizontally changes more violent.Therefore, Think that the wedge-shaped body Model a of no free gas is corresponding with there is the wedge-shaped body Model b of free gas to be less than reference amplitude to forward modeling spectral line amplitude Be lower hydrate concentration and larger thickness the case where.

(4) Fig. 7 is the seismic profile schematic diagram of hydrate target area in the embodiment of the present application, as shown in fig. 7, choosing real Different hydrate reservoir target areas on the seismic profile of border, calculate the amplitude spectrum within the scope of corresponding hydrates stabilized zone, and from vibration Corresponding spectral line is extracted in width spectrum.Fig. 8 (a) -8 (d) is the seismic profile and its correspondence of target area in the embodiment of the present application Practical spectral line schematic diagram, Fig. 8 (a) indicate Fig. 7 in 1 west side of region seismic profile schematic diagram, Fig. 8 (c) indicate 1 west side of region Seismic profile the corresponding practical spectral line of amplitude spectrum, the target frequency of corresponding extraction is 1.8Hz.Fig. 8 (b) indicates Fig. 7 The seismic profile schematic diagram in middle 1 east side of region, Fig. 8 (d) indicate the corresponding actual spectrum of amplitude spectrum of the seismic profile in 1 east side of region Line, the target frequency of corresponding extraction are 1.8Hz.Judge have under hydrate layer according to the utilization peak-to-valley ratio that step (2) provides Standard without the gas-bearing formation that dissociates, calculating 1 east and west sides of region using formula (9), (peak-to-valley ratio of Fig. 8 (a) and Fig. 8 (b) is respectively 4.52 and 9.15, corresponding is the case where there are free gases under hydrate layer, that is, has the wedge-shaped body Model b of free gas.Fig. 9 (a) -9 It (d) is the seismic profile of target area and its corresponding practical spectral line schematic diagram, Fig. 9 (a) table in another embodiment of the application The seismic profile schematic diagram in thready pulse region west side in diagram 7, Fig. 9 (c) indicate the amplitude spectrum of the seismic profile in thready pulse region west side Corresponding practical spectral line, the target frequency of corresponding extraction are 6Hz.Fig. 9 (b) indicates the earthquake in thready pulse region east side in Fig. 7 Diagrammatic cross-section, Fig. 9 (d) indicates the corresponding practical spectral line of amplitude spectrum of the seismic profile in thready pulse region east side, corresponding to mention The target frequency taken is 6Hz.Equally calculating thready pulse region east and west sides, (Fig. 9 (a) and the peak-to-valley ratio of Fig. 9 (b)) are respectively 1.45 and 2.14, it is corresponding be under hydrate layer without free gas the case where, i.e., without the wedge-shaped body Model a of free gas.It calculates Fig. 8 (a)- Average amplitude value (Fig. 8 (c) and Fig. 8 (d)) of the 1 east and west sides spectral line of region within the scope of different CDP in 8 (d), control has free It is provided in the forward modeling spectral line (Fig. 6 (b)) and step (3) of the wedge-shaped body Model b of gas and judges that hydrate reservoir thickness and hydrate are full With the evaluation criterion of degree, the thickness and saturation degree of hydrate layer are judged.For region 1, CDP is from the spectral line within the scope of 400-450 Average value is 1.5, hydrate concentration 7%, with a thickness of 280ms；CDP is from the spectral line average value within the scope of 450-490 2.5, hydrate concentration 14%, with a thickness of 280ms；CDP is 1 from the spectral line average value within the scope of 490-580, and hydrate is full It is 4% with degree, with a thickness of 280ms.Calculate thready pulse east and west sides spectral line being averaged within the scope of different CDP in Fig. 9 (a) -9 (d) Amplitude (Fig. 9 (c) and Fig. 9 (d)), compares in forward modeling spectral line (Fig. 6 (a)) and step (3) without the wedge-shaped body Model a of free gas The evaluation criterion for judging hydrate reservoir thickness and hydrate concentration is provided, judges the thickness and saturation degree of hydrate layer.It is right In thready pulse region, CDP is 1 from the spectral line average value within the scope of 730-740,755-770,790-830, and hydrate concentration is 8%, with a thickness of 70ms；CDP from the spectral line average value within the scope of 740-755 be 1.4, hydrate concentration 10%, with a thickness of 70ms (needs to judge under hydrate layer whether there is or not free gas, therefore final purpose before evaluation hydrate concentration and thickness It is to evaluate and whether have free gas, hydrate concentration and thickness under hydrate layer)；CDP is from the spectral line within the scope of 770-790 Average value is 2, hydrate concentration 15%, with a thickness of 70ms.Similar analysis is also made in other regions in Fig. 6 (a) -6 (b).

(5) it based on the description in step (4) to different hydrate target areas physical property characteristic, is stored up using the hydrate preferably gone out Layer petrophysical model (Fig. 2 (d)), and in conjunction with log data establish the rate pattern of the whole district (rate pattern is exactly according to step 4 (whether there is or not free gas, hydrate layer thickness and hydrate saturations under hydrate layer for the result described to hydrate layer physical property characteristic Degree), utilize the different hydrations of petrophysical model (providing the relationship between hydrate concentration and hydrate formation speed) calculating The speed of object target area, to establish rate pattern.To speed and density model, (density model utilizes volume density calculation formula It is calculated or is obtained by density log curve) utilize convolution model, the zero-offset earthquake record of available synthesis.If The zero-offset earthquake record of synthesis and the main wave character of actual shifts section are almost the same, can be with right in verification step 4 The correctness of hydrate target area physical property characteristic evaluation result.Figure 10 is the actual shifts section in the application one embodiment Schematic diagram, Figure 11 are the whole district's rate patterns obtained in the application one embodiment using Target Modeling method combination log data Schematic diagram, Figure 12 are the earthquake record schematic diagrames that rate pattern synthesizes in the embodiment of the present application.Zero bias are synthesized using convolution model It moves away from earthquake record (Figure 12), by the way that it is compared the comparison such as wave character with the section (Figure 10) after actual shifts, Complete the verifying described to different target area hydrate reservoir physical property characteristic in step (4).If the zero-offset earthquake of synthesis Record and actual shifts section main feature are almost the same, the hydrate that can be obtained with verification step 4 to hydrate target area Whether there is or not the correctness of free gas, hydrate layer thickness and hydrate concentration information under layer.

Gas hydrates seismic data processing technique provided by the embodiments of the present application, for target exploratory area, using being based on The petrophysical seismic forward simulation result of hydrate (forward modeling peak-to-valley ratio and forward modeling spectral line), obtains the physical property of target hydrate Characteristic evaluating standard (whether there is the evaluation criterion of free gas, the evaluation mark of hydrate layer thickness and saturation degree under hydrate layer It is quasi-).Whether the waveform to actual seismic data and amplitude spectrum signature are analyzed again, be finally completed hydrate reservoir and underlied trip From the evaluation that gas and water closes object reservoir thickness and saturation degree.Provide the half of a kind of description gas hydrate reservoir physical property feature Quantitative approach is selected by being fitted using different hydrate petrophysical models to the sample data in hydrate exploration area The petrophysical model for selecting suitable hydrate exploration area solves same hydrate reservoir petrophysical model in different exploratory areas Adaptability problem, the limitation of relatively thin hydrate layer can only be identified by addition also breaching tlc analysis technology.

Based on gas hydrates seismic data processing technique described above, this specification one or more embodiment is also A kind of gas hydrates seismic data process device is provided.The device may include having used this specification embodiment institute It states the system (including distributed system) of method, software (application), module, component, server, client etc. and combines necessary Implement the device of hardware.Device based on same innovation thinking, in one or more embodiments of this specification embodiment offer As described in the following examples.Since the implementation that device solves the problems, such as is similar to method, this specification embodiment tool The implementation of the device of body may refer to the implementation of preceding method, and overlaps will not be repeated.It is used below, term " unit " Or the combination of the software and/or hardware of predetermined function may be implemented in " module ".Although device described in following embodiment compared with It is realized goodly with software, but the realization of the combination of hardware or software and hardware is also that may and be contemplated.

Specifically, Figure 13 is the module of gas hydrates seismic data process device one embodiment provided by the present application Structural schematic diagram, as shown in figure 13, gas hydrates seismic data process device provided herein includes: modeling method Determining module 131, model building module 132, evaluation criterion determining module 133, actual seismic data processing module 134, feature Information determination module 135.

Modeling method determining module 131 can be used for utilizing hydrate reservoir according to the log data in hydrate exploration area Rock physics modeling method is fitted sample data, obtains Target Modeling method；

Model building module 132, the wedge-shaped body Model that can be used for that Target Modeling method is utilized to construct hydrate, and according to The wedge-shaped body Model carries out the forward modeling of seismic data, obtains synthetic seismogram, the wedge-shaped body Model includes gas water Close the corresponding speed of earth formation and stratum, the density information of object reservoir；

Evaluation criterion determining module 133 can be used for constructing the trip of gas hydrates according to the synthetic seismogram From gas evaluation criterion, saturation degree Thickness Evaluation standard；

Actual seismic data processing module 134 can be used for obtaining the reality of the target area in the hydrate exploration area Seismic data is composed according to the actual seismic data acquisition actual amplitude；

Characteristic information determining module 135 can be used for being composed according to the actual amplitude, the free gas evaluation criterion, institute Saturation degree Thickness Evaluation standard is stated, determines the hydrate characteristic information of the target area.

Gas hydrates seismic data process device provided by the present application, for target exploratory area, using based on hydrate Petrophysical seismic forward simulation result (forward modeling peak-to-valley ratio and forward modeling spectral line), the physical property characteristic for obtaining target hydrate is commented Price card is quasi- (whether there is the evaluation criterion of free gas, the evaluation criterion of hydrate layer thickness and saturation degree under hydrate layer).Again Waveform and amplitude spectrum signature to actual seismic data are analyzed, be finally completed hydrate reservoir whether underlie free gas, The evaluation of hydrate reservoir thickness and saturation degree.Provide a kind of sxemiquantitative side for describing gas hydrate reservoir physical property feature Method, by being fitted using different hydrate petrophysical models to the sample data in hydrate exploration area, selection is suitble to The petrophysical model in hydrate exploration area solves same hydrate reservoir petrophysical model in the adaptability in different exploratory areas Problem, the limitation of relatively thin hydrate layer can only be identified by addition also breaching tlc analysis technology.

It should be noted that device described above can also include other embodiment party according to the description of embodiment of the method Formula, concrete implementation mode are referred to the description of related method embodiment, do not repeat one by one herein.

It is above-mentioned that this specification specific embodiment is described.Other embodiments are in the scope of the appended claims It is interior.In some cases, the movement recorded in detail in the claims or step can be come according to the sequence being different from embodiment It executes and desired result still may be implemented.In addition, process depicted in the drawing not necessarily require show it is specific suitable Sequence or consecutive order are just able to achieve desired result.In some embodiments, multitasking and parallel processing be also can With or may be advantageous.

Method or apparatus described in above-described embodiment that this specification provides can realize that business is patrolled by computer program It collects and records on a storage medium, the storage medium can be read and be executed with computer, realize this specification embodiment institute The effect of description scheme.

The above-mentioned gas hydrates seismic data processing technique or device that this specification embodiment provides can calculate Corresponding program instruction is executed to realize, such as using the c++ language of windows operating system in the end PC reality by processor in machine Existing, Linux system is realized or other are for example realized using android, iOS system programming language in intelligent terminal, and Processing logic realization based on quantum computer etc..A kind of gas hydrates earthquake data processing system that this specification provides One embodiment in, Figure 14 is a kind of module of gas hydrates earthquake data processing system embodiment provided by the present application Structural schematic diagram, as shown in figure 14, the gas hydrates earthquake data processing system that another embodiment of the application provides can be with Including processor 141 and for the memory 142 of storage processor executable instruction,

Processor 141 and memory 142 pass through bus 143 and complete mutual communication；

The processor 141 is used to call the program instruction in the memory 142, to execute above-mentioned each natural gas hydration Method provided by object seismic data processing technique embodiment, for example, modeling method determining module, for according to hydrate The log data of exploration area is fitted sample data using hydrate reservoir rock physics modeling method, obtains target and builds Mould method；Model building module, for the wedge-shaped body Model using Target Modeling method building hydrate, and according to described wedge-shaped Body Model carries out the forward modeling of seismic data, obtains synthetic seismogram, the wedge-shaped body Model includes gas hydrates reservoir The corresponding speed of earth formation and stratum, density information；Evaluation criterion determining module, for being remembered according to the synthesis earthquake Record, constructs free gas evaluation criterion, the saturation degree Thickness Evaluation standard of gas hydrates；Actual seismic data processing module, It is practical according to the actual seismic data acquisition for obtaining the actual seismic data of the target area in the hydrate exploration area Amplitude spectrum；Characteristic information determining module, for according to actual amplitude spectrum, the free gas evaluation criterion, the saturation degree Thickness Evaluation standard determines the hydrate characteristic information of the target area.

It should be noted that specification device described above can also include it according to the description of related method embodiment His embodiment, concrete implementation mode are referred to the description of embodiment of the method, do not repeat one by one herein.In the application Various embodiments are described in a progressive manner, and the same or similar parts between the embodiments can be referred to each other, often What a embodiment stressed is the difference from other embodiments.For hardware+program class embodiment, Since it is substantially similar to the method embodiment, so being described relatively simple, related place is said referring to the part of embodiment of the method It is bright.

This specification embodiment is not limited to meet industry communication standard, standard computer data processing sum number According to situation described in storage rule or this specification one or more embodiment.The right way of conduct is made in certain professional standards or use by oneself In formula or the practice processes of embodiment description embodiment modified slightly also may be implemented above-described embodiment it is identical, it is equivalent or The implementation result being anticipated that after close or deformation.Using these modifications or deformed data acquisition, storage, judgement, processing side The embodiment of the acquisitions such as formula still may belong within the scope of the optional embodiment of this specification embodiment.

In the 1990s, the improvement of a technology can be distinguished clearly be on hardware improvement (for example, Improvement to circuit structures such as diode, transistor, switches) or software on improvement (improvement for method flow).So And with the development of technology, the improvement of current many method flows can be considered as directly improving for hardware circuit. Designer nearly all obtains corresponding hardware circuit by the way that improved method flow to be programmed into hardware circuit.Cause This, it cannot be said that the improvement of a method flow cannot be realized with hardware entities module.For example, programmable logic device (Programmable Logic Device, PLD) (such as field programmable gate array (Field Programmable Gate Array, FPGA)) it is exactly such a integrated circuit, logic function determines device programming by user.By designer Voluntarily programming comes a digital display circuit " integrated " on a piece of PLD, designs and makes without asking chip maker Dedicated IC chip.Moreover, nowadays, substitution manually makes IC chip, this programming is also used instead mostly " is patrolled Volume compiler (logic compiler) " software realizes that software compiler used is similar when it writes with program development, And the source code before compiling also write by handy specific programming language, this is referred to as hardware description language (Hardware Description Language, HDL), and HDL is also not only a kind of, but there are many kind, such as ABEL (Advanced Boolean Expression Language)、AHDL(Altera Hardware Description Language)、Confluence、CUPL(Cornell University Programming Language)、HDCal、JHDL (Java Hardware Description Language)、Lava、Lola、MyHDL、PALASM、RHDL(Ruby Hardware Description Language) etc., VHDL (Very-High-Speed is most generally used at present Integrated Circuit Hardware Description Language) and Verilog.Those skilled in the art also answer This understands, it is only necessary to method flow slightly programming in logic and is programmed into integrated circuit with above-mentioned several hardware description languages, The hardware circuit for realizing the logical method process can be readily available.

Controller can be implemented in any suitable manner, for example, controller can take such as microprocessor or processing The computer for the computer readable program code (such as software or firmware) that device and storage can be executed by (micro-) processor can Read medium, logic gate, switch, specific integrated circuit (Application Specific Integrated Circuit, ASIC), the form of programmable logic controller (PLC) and insertion microcontroller, the example of controller includes but is not limited to following microcontroller Device: ARC 625D, Atmel AT91SAM, Microchip PIC18F26K20 and Silicone Labs C8051F320 are deposited Memory controller is also implemented as a part of the control logic of memory.It is also known in the art that in addition to Pure computer readable program code mode is realized other than controller, can be made completely by the way that method and step is carried out programming in logic Controller is obtained to come in fact in the form of logic gate, switch, specific integrated circuit, programmable logic controller (PLC) and insertion microcontroller etc. Existing identical function.Therefore this controller is considered a kind of hardware component, and to including for realizing various in it The device of function can also be considered as the structure in hardware component.Or even, it can will be regarded for realizing the device of various functions For either the software module of implementation method can be the structure in hardware component again.

System, device, module or the unit that above-described embodiment illustrates can specifically realize by computer chip or entity, Or it is realized by the product with certain function.It is a kind of typically to realize that equipment is computer.Specifically, computer for example may be used Think personal computer, laptop computer, vehicle-mounted human-computer interaction device, cellular phone, camera phone, smart phone, individual Digital assistants, media player, navigation equipment, electronic mail equipment, game console, tablet computer, wearable device or The combination of any equipment in these equipment of person.

Although this specification one or more embodiment provides the method operating procedure as described in embodiment or flow chart, It but may include more or less operating procedure based on conventional or without creativeness means.The step of being enumerated in embodiment Sequence is only one of numerous step execution sequence mode, does not represent and unique executes sequence.Device in practice or When end product executes, can be executed according to embodiment or the execution of method shown in the drawings sequence or parallel (such as it is parallel The environment of processor or multiple threads, even distributed data processing environment).The terms "include", "comprise" or its Any other variant is intended to non-exclusive inclusion so that include the process, methods of a series of elements, product or Equipment not only includes those elements, but also including other elements that are not explicitly listed, or further include for this process, Method, product or the intrinsic element of equipment.In the absence of more restrictions, being not precluded is including the element There is also other identical or equivalent elements in process, method, product or equipment.The first, the second equal words are used to indicate name Claim, and does not indicate any particular order.

For convenience of description, it is divided into various modules when description apparatus above with function to describe respectively.Certainly, implementing this The function of each module can be realized in the same or multiple software and or hardware when specification one or more, it can also be with The module for realizing same function is realized by the combination of multiple submodule or subelement etc..Installation practice described above is only It is only illustrative, for example, in addition the division of the unit, only a kind of logical function partition can have in actual implementation Division mode, such as multiple units or components can be combined or can be integrated into another system or some features can be with Ignore, or does not execute.Another point, shown or discussed mutual coupling, direct-coupling or communication connection can be logical Some interfaces are crossed, the indirect coupling or communication connection of device or unit can be electrical property, mechanical or other forms.

The present invention be referring to according to the method for the embodiment of the present invention, the process of device (system) and computer program product Figure and/or block diagram describe.It should be understood that every one stream in flowchart and/or the block diagram can be realized by computer program instructions The combination of process and/or box in journey and/or box and flowchart and/or the block diagram.It can provide these computer programs Instruct the processor of general purpose computer, special purpose computer, Embedded Processor or other programmable data processing devices to produce A raw machine, so that being generated by the instruction that computer or the processor of other programmable data processing devices execute for real The device for the function of being specified in present one or more flows of the flowchart and/or one or more blocks of the block diagram.

These computer program instructions, which may also be stored in, is able to guide computer or other programmable data processing devices with spy Determine in the computer-readable memory that mode works, so that it includes referring to that instruction stored in the computer readable memory, which generates, Enable the manufacture of device, the command device realize in one box of one or more flows of the flowchart and/or block diagram or The function of being specified in multiple boxes.

These computer program instructions also can be loaded onto a computer or other programmable data processing device, so that counting Series of operation steps are executed on calculation machine or other programmable devices to generate computer implemented processing, thus in computer or The instruction executed on other programmable devices is provided for realizing in one or more flows of the flowchart and/or block diagram one The step of function of being specified in a box or multiple boxes.

In a typical configuration, calculating equipment includes one or more processors (CPU), input/output interface, net Network interface and memory.

Memory may include the non-volatile memory in computer-readable medium, random access memory (RAM) and/or The forms such as Nonvolatile memory, such as read-only memory (ROM) or flash memory (flash RAM).Memory is computer-readable medium Example.

Computer-readable medium includes permanent and non-permanent, removable and non-removable media can be by any method Or technology come realize information store.Information can be computer readable instructions, data structure, the module of program or other data. The example of the storage medium of computer includes, but are not limited to phase change memory (PRAM), static random access memory (SRAM), moves State random access memory (DRAM), other kinds of random access memory (RAM), read-only memory (ROM), electric erasable Programmable read only memory (EEPROM), flash memory or other memory techniques, read-only disc read only memory (CD-ROM) (CD-ROM), Digital versatile disc (DVD) or other optical storage, magnetic cassettes, tape magnetic disk storage, graphene stores or other Magnetic storage device or any other non-transmission medium, can be used for storage can be accessed by a computing device information.According to herein In define, computer-readable medium does not include temporary computer readable media (transitory media), such as the data of modulation Signal and carrier wave.

It will be understood by those skilled in the art that this specification one or more embodiment can provide as method, system or calculating Machine program product.Therefore, this specification one or more embodiment can be used complete hardware embodiment, complete software embodiment or The form of embodiment combining software and hardware aspects.Moreover, this specification one or more embodiment can be used at one or It is multiple wherein include computer usable program code computer-usable storage medium (including but not limited to magnetic disk storage, CD-ROM, optical memory etc.) on the form of computer program product implemented.

All the embodiments in this specification are described in a progressive manner, same and similar portion between each embodiment Dividing may refer to each other, and each embodiment focuses on the differences from other embodiments.Especially for system reality For applying example, since it is substantially similar to the method embodiment, so being described relatively simple, related place is referring to embodiment of the method Part explanation.In the description of this specification, reference term " one embodiment ", " some embodiments ", " example ", The description of " specific example " or " some examples " etc. means specific features described in conjunction with this embodiment or example, structure, material Or feature is contained at least one embodiment or example of this specification.In the present specification, to the signal of above-mentioned term Property statement be necessarily directed to identical embodiment or example.Moreover, particular features, structures, materials, or characteristics described It may be combined in any suitable manner in any one or more of the embodiments or examples.In addition, without conflicting with each other, this The technical staff in field can be by the spy of different embodiments or examples described in this specification and different embodiments or examples Sign is combined.

The foregoing is merely the embodiments of this specification one or more embodiment, are not limited to book explanation Book one or more embodiment.To those skilled in the art, this specification one or more embodiment can have various Change and variation.All any modification, equivalent replacement, improvement and so within the spirit and principles of the present application should all include Within scope of the claims.

Claims

1. a kind of gas hydrates seismic data processing technique characterized by comprising

According to the log data in hydrate exploration area, sample data is intended using hydrate reservoir rock physics modeling method It closes, obtains Target Modeling method；

Seismic data is carried out using the wedge-shaped body Model of Target Modeling method building hydrate, and according to the wedge-shaped body Model Forward modeling, obtains synthetic seismogram, and the wedge-shaped body Model includes that the earth formation of gas hydrates reservoir and stratum correspond to Speed, density information；

According to the synthetic seismogram, free gas evaluation criterion, the saturation degree Thickness Evaluation standard of gas hydrates are constructed；

The actual seismic data for obtaining the target area in the hydrate exploration area are practical according to the actual seismic data acquisition Amplitude spectrum；

According to actual amplitude spectrum, the free gas evaluation criterion, the saturation degree Thickness Evaluation standard, the target is determined The hydrate characteristic information in region.

2. a kind of gas hydrates seismic data processing technique as described in claim 1, which is characterized in that the wedge Model includes the wedge-shaped body Model of free gas, without the wedge-shaped body Model of free gas；

There are the first peak-to-valley ratio and the nothing of the corresponding synthetic seismogram of the wedge-shaped body Model of free gas free described in obtaining respectively Second peak-to-valley ratio of the corresponding synthetic seismogram of the wedge-shaped body Model of gas；

3. a kind of gas hydrates seismic data processing technique as claimed in claim 2, which is characterized in that the building Free gas evaluation criterion includes:

If the ratio of first peak-to-valley ratio and second peak-to-valley ratio is more than or equal to second peak-to-valley ratio, the mesh is judged Whether the peak-to-valley ratio in mark region is more than or equal to the ratio of first peak-to-valley ratio Yu second peak-to-valley ratio；

If judging, the peak-to-valley ratio of the target area is more than or equal to the ratio of first peak-to-valley ratio and second peak-to-valley ratio, The gas hydrates layer for determining the target area includes free gas；

If judging, the peak-to-valley ratio of the target area is less than the ratio of first peak-to-valley ratio and second peak-to-valley ratio, it is determined that The gas hydrates layer of the target area does not include free gas.

4. a kind of gas hydrates seismic data processing technique as claimed in claim 2, which is characterized in that the free gas Evaluation criterion includes:

If the ratio of first peak-to-valley ratio and second peak-to-valley ratio is less than second peak-to-valley ratio, the hydrate is judged Whether the thickness of the hydrate layer of exploration area is more than or equal to preset threshold；

If judging, the thickness of the hydrate layer in the hydrate exploration area is more than or equal to the preset threshold, when the target area When the peak-to-valley ratio in domain is more than or equal to first peak-to-valley ratio, determine that the gas hydrates layer of the target area includes free Gas determines the gas hydrates of the target area when the peak-to-valley ratio of the target area is less than first peak-to-valley ratio Layer does not include free gas；

If judging, the thickness of the hydrate layer in the hydrate exploration area is less than the preset threshold, when the target area When peak-to-valley ratio is greater than second peak-to-valley ratio, determine that the gas hydrates layer of the target area includes free gas, when described When the peak-to-valley ratio of target area is less than or equal to second peak-to-valley ratio, determine that the gas hydrates layer of the target area does not wrap Containing free gas.

5. a kind of gas hydrates seismic data processing technique as claimed in claim 2, which is characterized in that the saturation is thick Degree evaluation criterion construction method include:

Fourier transformation is carried out to the synthetic seismogram, the corresponding amplitude spectrum of the synthetic seismogram is obtained, from described The corresponding original spectral line of target frequency is extracted in amplitude spectrum；

Using the seismic data in the hydrate exploration area in the pre-determined distance of well, the original spectral line is corrected, Obtain correction spectral line；

According to the correction spectral line, reference amplitude is determined, and according to the reference amplitude, the correction spectral line, the hydrate The log data of exploration area constructs the saturation degree Thickness Evaluation standard.

6. a kind of gas hydrates seismic data processing technique as claimed in claim 5, which is characterized in that the building Saturation degree Thickness Evaluation standard includes:

If the amplitude of the correction spectral line is greater than the reference amplitude value, it is determined that saturation degree is greater than default saturation degree, thickness Greater than preset thickness；

If it is described correction spectral line amplitude be less than the reference amplitude value, judge the hydrate exploration area saturation degree and The variation degree of thickness horizontally；

If the variation degree of the saturation degree horizontally is greater than the variation degree of the thickness horizontally, it is determined that saturation degree Less than the default saturation degree, thickness is greater than the preset thickness；

If the variation degree of the saturation degree horizontally is less than the variation degree of the thickness horizontally, it is determined that saturation degree Greater than the default saturation degree, thickness is less than the preset thickness.

7. a kind of gas hydrates seismic data processing technique as claimed in claim 5, which is characterized in that described to described Original spectral line is corrected, and obtains correction spectral line, comprising:

According to the seismic data in the pre-determined distance of well in the hydrate exploration area, the corresponding reality of the target frequency is extracted Spectral line, and obtain the actual (real) thickness of hydrate layer, practical saturation degree in the hydrate exploration area；

Obtain the average amplitude value of the practical spectral line；

The original spectral line is corrected according to the average amplitude value, the actual (real) thickness, practical saturation degree, described in acquisition Correct spectral line.

8. such as a kind of described in any item gas hydrates seismic data processing techniques of claim 1-7, which is characterized in that institute State method further include:

According to the hydrate characteristic information of the target area, the hydrate exploration area is constructed using the Target Modeling method Rate pattern；

The zero-offset earthquake record is matched with the main wave character of the actual shifts section of the target area, Determine whether the hydrate characteristic information of the target area is accurate.

9. a kind of gas hydrates seismic data process device characterized by comprising

Modeling method determining module is built for the log data according to hydrate exploration area using hydrate reservoir rock physics Mould method is fitted sample data, obtains Target Modeling method；

Model building module, for the wedge-shaped body Model using Target Modeling method building hydrate, and according to the wedge Model carries out the forward modeling of seismic data, obtains synthetic seismogram, the wedge-shaped body Model includes gas hydrates reservoir The corresponding speed of earth formation and stratum, density information；

Evaluation criterion determining module, for constructing the free gas evaluation mark of gas hydrates according to the synthetic seismogram Quasi-, saturation degree Thickness Evaluation standard；

Actual seismic data processing module, the actual seismic data of the target area for obtaining the hydrate exploration area, root It is composed according to the actual seismic data acquisition actual amplitude；

Characteristic information determining module, for according to actual amplitude spectrum, the free gas evaluation criterion, the saturation degree thickness Evaluation criterion determines the hydrate characteristic information of the target area.

10. a kind of gas hydrates earthquake data processing system, which is characterized in that handled including processor and for storage The memory of device executable instruction, the processor are realized as described in any one of claim 1 to 7 when executing described instruction The step of method.