CN112859163B - Method and device for determining stratum quality factor change of fracturing area by using scattered waves - Google Patents

Abstract

The application provides a method and a device for determining stratum quality factor change of a fractured zone by using scattered waves, wherein the method comprises the following steps: acquiring scattered waves in seismic waves in N different time periods in a target area, wherein the seismic waves are seismic waves generated by microseismic points in the target area; acquiring amplitude spectrums of the scattered waves in N different time periods according to the scattered waves; determining stratum quality factors corresponding to N different time periods of a target area according to the amplitude spectrums of the scattered waves in the N different time periods; and acquiring the change of the formation quality factor of the fracturing area in the target area along with time according to the formation quality factors respectively corresponding to the N different time periods, wherein the change is used for guiding the exploitation of the oil and gas reservoir. The method estimates the change of the formation quality factor of the fracturing area by using the amplitude spectrum of the scattering wave, reduces the parameter calculation amount compared with the prior art, can accurately and quickly obtain the formation quality factor, and is more favorable for guiding the exploitation of an oil-gas reservoir.

Description

Method and device for determining the variation of formation quality factor in fracturing area using scattered waves

technical field

The embodiments of the present application relate to the technical field of seismic exploration, and in particular, to a method and device for determining the variation of formation quality factor in a fracturing area by using scattered waves.

Background technique

In the process of seismic wave propagation, due to the viscoelasticity and inhomogeneity of the formation medium itself, the seismic wave energy will be attenuated, which is called intrinsic attenuation. The inherent attenuation is jointly determined by the lithological structure, porosity, saturation, permeability and other influencing parameters of the underground medium. The formation attenuation characteristics are usually represented by the formation quality factor Q. Therefore, the formation quality factor Q can be used as a medium parameter to analyze the lithology such as sand and mudstone and the indication of oil and gas reservoirs.

The method for obtaining formation quality factor in the prior art is mainly realized through the following steps: S1, obtaining seismic reflection data recorded by the seismic data, and obtaining a smooth local time-frequency amplitude spectrum by using shaping regularization and least square inversion technology according to the seismic reflection data; S2. Calculate the peak frequency based on the rake wavelet decomposition according to the local time-frequency amplitude spectrum; S3, estimate the formation quality factor according to the relationship between the rake wavelet peak frequency and the formation quality factor Q value.

However, the amount of parameters obtained in the above processing method is large, which leads to a complicated processing process.

SUMMARY OF THE INVENTION

The present application provides a method and a device for determining the change of formation quality factor in a fracturing area by using scattered waves, so as to solve the problem that the quantity of parameters obtained in the prior art is large and the processing process is complicated.

In a first aspect, the present application provides a method for determining the variation of formation quality factor in a fracturing area by using scattered waves, including:

The scattered waves in the seismic waves in N different time periods in the target area are obtained, and the seismic waves are the seismic waves generated by the microseismic points in the target area.

According to the scattered waves, the amplitude spectra of the scattered waves in N different time periods are obtained.

According to the amplitude spectra of scattered waves in N different time periods, the formation quality factors corresponding to N different time periods in the target area respectively are determined, where N is an integer greater than or equal to 2.

According to the formation quality factors corresponding to N different time periods respectively, the change of the formation quality factor of the fracturing zone in the target area with time is obtained, and the change is used to guide the exploitation of oil and gas reservoirs.

Optionally, according to the amplitude spectra of scattered waves in N different time periods, determine the formation quality factors corresponding to N different time periods in the target area respectively, including:

For each microseismic event e _ij in the ith time period in the N different time periods, according to the amplitude spectrum of the scattered wave of the microseismic event e _ij , obtain the formation quality factor Q _ij corresponding to the microseismic event e _ij . The value is an integer from 1 to N, and the value of j is the number M _i of all microseismic events that can be clearly recorded in the ith time period; according to the formation quality factor corresponding to each microseismic event e _ij in the ith time period Q _ij , determine the formation quality factor Q _i of the target area corresponding to the ith time period.

Optionally, obtain the formation quality factor Q _ij corresponding to the microseismic event e _ij according to the amplitude spectrum of the scattered wave of the microseismic event e _ij , including:

Divide the scattered waves of the microseismic event e _ij into K sections, obtain the amplitude spectrum of each section of the scattered waves in the K section, and obtain the corresponding formation quality factor according to the amplitude spectrum of each section of the scattered waves; The corresponding formation quality factors are summed and averaged to obtain formation quality factors Q _ij corresponding to the microseismic event e _ij , where K is an integer greater than or equal to 1.

Optionally, the scattered waves of the microseismic event e _ij are divided into K sections, the amplitude spectrum of each scattered wave in the K section is obtained, and the corresponding formation quality factor is obtained according to the amplitude spectrum of each scattered wave, including:

According to the following formula 1, the formation quality factor corresponding to each section of scattered wave is obtained;

表示微震事件e_ij的散射波的第k段的振幅谱，k的取值为1至K的整数，

表示第k段散射波相对于直达波的走时，

表示微震事件e_ij的散射波的第k段获取的地层品质因子，S_ij(f)表示第k段直达波的振幅谱，f表示散射波的频率。In formula 1,

represents the amplitude spectrum of the k-th segment of the scattered wave of the microseismic event e _ij , where k is an integer from 1 to K,

represents the travel time of the k-th scattered wave relative to the direct wave,

S _ij (f) represents the amplitude spectrum of the direct wave in the k- _th segment, and f represents the frequency of the scattered wave.

Optionally, according to the formation quality factor Q _ij corresponding to each microseismic event e _ij in the ith time period, determine the formation quality factor Qi of the target area corresponding to the _ith time period, including:

The reverse time migration positioning method is used to map the formation quality factor Q _{ij corresponding to each microseismic event e ij in} the Mi microseismic events to the corresponding position of the target area; all formation quality factors Q _ij mapped to the corresponding position of the target area are mapped _ij is summed and averaged to determine the formation quality factor Q _i of the target area corresponding to the ith time period.

Optionally, before acquiring the amplitude spectra of the scattered waves in N different time periods according to the scattered waves, the method further includes:

Obtain the direct wave in the seismic wave; according to the direct wave, obtain the amplitude spectrum of the direct wave.

According to the scattered wave, obtain the amplitude spectrum of the scattered wave in N different time periods, including:

According to the amplitude spectrum of the direct wave and the scattered wave, the amplitude spectrum of the scattered wave in N different time periods is obtained.

In a second aspect, the present application provides a device for determining the change of formation quality factor in a fracturing area by using scattered waves, including:

The first acquisition module is used to acquire the scattered waves in the seismic waves in N different time periods in the target area, and the seismic waves are seismic waves generated by the microseismic points in the target area; and according to the scattered waves, acquire the scattered waves in the N different time periods. Amplitude spectrum.

The determining module is configured to determine the formation quality factors corresponding to N different time periods in the target area according to the amplitude spectrum of the scattered waves in N different time periods, where N is an integer greater than or equal to 2.

The second obtaining module is used for obtaining the time-dependent change of the formation quality factor of the fracturing zone in the target area according to the formation quality factors corresponding to N different time periods, and the change is used to guide the exploitation of the oil and gas reservoir.

Optionally, determine the module, which is specifically used for:

For each microseismic event e _ij in the ith time period in the N different time periods, according to the amplitude spectrum of the scattered wave of the microseismic event e _ij , obtain the formation quality factor Q _ij corresponding to the microseismic event e _ij . The value is an integer from 1 to N, and the value of j is the number M _i of all microseismic events that can be clearly recorded in the ith time period; according to the formation quality factor corresponding to each microseismic event e _ij in the ith time period Q _ij , determine the formation quality factor Q _i of the target area corresponding to the ith time period.

Optionally, determine the module, which is specifically used for:

Divide the scattered waves of the microseismic event e _ij into K sections, obtain the amplitude spectrum of each section of the scattered waves in the K section, and obtain the corresponding formation quality factor according to the amplitude spectrum of each section of the scattered waves; The corresponding formation quality factors are summed and averaged to obtain formation quality factors Q _ij corresponding to the microseismic event e _ij , where K is an integer greater than or equal to 1.

Optionally, determine the module, which is specifically used for:

According to the following formula 1, the formation quality factor corresponding to each section of scattered wave is obtained;

表示微震事件e_ij的散射波的第k段的振幅谱，k的取值为1至K的整数，

表示第k段散射波相对于直达波的走时，

表示微震事件e_ij的散射波的第k段获取的地层品质因子，S_ij(f)表示第k段直达波的振幅谱，f表示散射波的频率。In formula 1,

represents the amplitude spectrum of the k-th segment of the scattered wave of the microseismic event e _ij , where k is an integer from 1 to K,

represents the travel time of the k-th scattered wave relative to the direct wave,

S _ij (f) represents the amplitude spectrum of the direct wave in the k- _th segment, and f represents the frequency of the scattered wave.

Optionally, determine the module, which is specifically used for:

The reverse time migration positioning method is used to map the formation quality factor Q _{ij corresponding to each microseismic event e ij in} the Mi microseismic events to the corresponding position of the target area; all formation quality factors Q _ij mapped to the corresponding position of the target area are mapped _ij is summed and averaged to determine the formation quality factor Q _i of the target area corresponding to the ith time period.

Optionally, before acquiring the amplitude spectra of the scattered waves in N different time periods according to the scattered waves, the first acquisition module is further configured to:

Obtain the direct wave in the seismic wave; according to the direct wave, obtain the amplitude spectrum of the direct wave.

According to the amplitude spectrum of the direct wave and the scattered wave, the amplitude spectrum of the scattered wave in N different time periods is obtained.

In a third aspect, the application provides an electronic device, comprising:

memory for storing program instructions;

The processor is configured to invoke the program instructions in the memory to execute the method for determining the change of the formation quality factor of the fracturing area by using the scattered wave according to the first aspect of the present application.

In a fourth aspect, the present application provides a computer-readable storage medium, where the computer storage medium stores a computer program, and when the computer program is executed by a processor, the determination of the formation quality factor of a fracturing zone by using scattered waves as described in the first aspect of the present application is realized. method of change.

In a fifth aspect, the present application provides a computer program product, including a computer program, which, when executed by a processor, implements the method for determining the variation of formation quality factor in a fracturing zone using scattered waves as described in the first aspect of the present application.

The method and device for determining the change of formation quality factor in a fracturing area using scattered waves provided by the present application, by acquiring scattered waves in seismic waves in N different time periods in the target area, the seismic waves are seismic waves generated by microseismic points in the target area; Scattered waves, obtain the amplitude spectra of scattered waves in N different time periods; according to the amplitude spectra of scattered waves in N different time periods, determine the formation quality factors corresponding to N different time periods in the target area, where N is greater than It is an integer equal to 2; according to the formation quality factors corresponding to N different time periods, the change of the formation quality factor of the fracturing zone in the target area over time is obtained, and the change is used to guide the exploitation of oil and gas reservoirs. The method uses the amplitude spectrum of the scattered wave to estimate the formation quality factor of the fracturing area. Compared with the existing technology, the amount of parameters to be obtained is reduced, the formation quality factor can be obtained accurately and quickly, and it is more helpful to guide the development of oil and gas reservoirs. .

Description of drawings

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following will briefly introduce the accompanying drawings used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description These are some embodiments of the present application, and for those of ordinary skill in the art, other drawings can also be obtained from these drawings without any creative effort.

FIG. 1 is a schematic flowchart of a method for determining the variation of formation quality factor in a fracturing zone by using scattered waves according to an embodiment of the present application;

2 is a schematic diagram of a microseismic monitoring structure in a well provided by an embodiment of the present application;

FIG. 3 is a schematic flowchart of a method for determining a change in formation quality factor in a fracturing area by using scattered waves according to another embodiment of the present application;

FIG. 4 is a schematic diagram of a scattered wave amplitude spectrum waveform according to an embodiment of the present application;

FIG. 5 is a schematic structural diagram of an apparatus for determining a change in formation quality factor in a fracturing area by using scattered waves according to an embodiment of the present application;

6 is a schematic structural diagram of an electronic device provided by an embodiment of the present application;

FIG. 7 is a schematic structural diagram of an electronic device provided by another embodiment of the present application.

Detailed ways

Exemplary embodiments will be described in detail herein, examples of which are illustrated in the accompanying drawings. Where the following description refers to the drawings, the same numerals in different drawings refer to the same or similar elements unless otherwise indicated. The implementations described in the illustrative examples below are not intended to represent all implementations consistent with this application. Rather, they are merely examples of apparatus and methods consistent with some aspects of the present application as recited in the appended claims.

Hereinafter, some terms in this application will be explained so as to facilitate the understanding of those skilled in the art:

Microseismic monitoring: It is a geophysical method to evaluate underground fractures and formation anisotropy by studying the artificial fractures in the formation during hydraulic fracturing, formation fractures, etc., which lead to changes in the underground stress field and generate seismic waves.

Scattered wave: From a physical point of view, if the stratum interface is uneven, when the scale of the concave (or convex) part of the stratum is smaller than the wavelength of the scattered wave, scattering will occur to form a scattered wave. In this application, the fracture produced by microseismic monitoring fracturing is a strong scatterer for incident seismic waves to generate scattered waves.

Formation quality factor Q: seismic waves will be attenuated when propagated in the formation, and the attenuation property is usually characterized by the formation quality factor Q. The following formula is commonly used to define: when the seismic wave propagates a distance of one wavelength, 2π times the ratio of the initial energy E to the consumed energy ΔE is the formation quality factor Q.

Amplitude Spectrum: The variation of the amplitude of a wave or wave train with frequency.

The embodiments of the present application may be applied to electronic devices, and the electronic devices may include: computers, tablet computers, etc., which are not limited in this application.

The method for obtaining the formation quality factor in the prior art is mainly realized through the following steps: S1. Obtain seismic reflection data recorded by the seismic data, and obtain a smooth local time-frequency amplitude spectrum by using shaping regularization and least square inversion technology according to the seismic reflection data; S2 . Calculate the peak frequency based on the rake wavelet decomposition according to the local time-frequency amplitude spectrum; S3, estimate the formation quality factor according to the relationship between the rake wavelet peak frequency and the formation quality factor Q value. However, the amount of parameters obtained in the above processing method is large, which leads to a complicated processing process.

Based on this technical problem, this application mainly considers the method of using microseismic monitoring equipment for downhole fracturing to generate scattered waves, and then obtains the amplitude spectrum of the scattered waves, and then obtains the formation quality factor of the fracturing area through the amplitude spectrum of the scattered waves. Therefore, compared with the prior art, the method reduces the amount of parameters to obtain, can obtain the formation quality factor accurately and quickly, and is more helpful for guiding the exploitation of oil and gas reservoirs.

The technical solutions of the present application will be described below with reference to several specific embodiments.

FIG. 1 is a schematic flowchart of a method for determining the variation of formation quality factor in a fracturing area by using scattered waves according to an embodiment of the present application. As shown in FIG. 1 , the method in this embodiment of the present application may include:

S101. Acquire scattered waves in seismic waves in N different time periods in the target area.

In this embodiment, the seismic waves are seismic waves generated by microseismic points in the target area. According to the microseismic monitoring method, the seismic waves and direct waves generated in the target area are acquired. Among them, the microseismic monitoring method includes two methods: ground monitoring and well monitoring. Since the ground monitoring method has high requirements on seismic exploration instruments, and the formation has serious absorption and attenuation of seismic waves, the well monitoring method is adopted in the embodiment of the present application. As shown, the geophone in Figure 2 is the receiving device in the microseismic monitoring equipment, and the monitoring well is the well where the target area is located. Well monitoring refers to deploying microseismic monitoring equipment in the monitoring well to receive the generated seismic waves when fracturing the well. The microseismic monitoring equipment then transmits the received seismic waves to electronic equipment on the ground such as a computer, and the above seismic waves include, for example, direct waves, scattered waves, and diffracted waves. Finally, the electronic device distinguishes the received seismic waves according to the travel time of the seismic waves, and performs cutting processing on the received seismic waves, such as diffracted waves, to obtain scattered waves in the seismic waves. Among them, the above-mentioned excision processing of the seismic waves, such as diffracted waves, belongs to the prior art, and details are not described herein again. Therefore, according to the seismic waves in the target area, the scattered waves in the seismic waves in N different time periods in the target area can be obtained.

S102 , according to the scattered waves, acquire amplitude spectra of the scattered waves in N different time periods.

In this embodiment, according to the Aki-Richards theory and the scattered waves obtained in S101, the amplitude spectra of the scattered waves in N different time periods are obtained, and the amplitude spectra of the scattered waves can be expressed by the following formula 2. The acquisition of the amplitude spectrum of the scattered wave according to the Aki-Richards theory belongs to the prior art, and details are not described herein again.

R(f)=G*H(f)*S(f) Formula 2

In formula 2, G represents the coupling degree between the seismic source and the formation, instrument response, geometric diffusion, reflection and transmission coefficients and other parameters that are not related to frequency; H(f) represents the influence parameter of the underground medium; S(f) represents the direct wave The amplitude spectrum of , R(f) represents the amplitude spectrum of the scattered wave.

S103 , according to the amplitude spectra of the scattered waves in the N different time periods, determine the formation quality factors respectively corresponding to the N different time periods of the target area.

In this embodiment, after acquiring the amplitude spectra of scattered waves in N different time periods according to S102, the formation quality factors corresponding to N different time periods in the target area respectively are determined. Optionally, the formation quality factor is represented by a Q value. Correspondingly, according to the amplitude spectra of scattered waves in N different time periods, the formation quality factor Q values corresponding to N different time periods in the target area respectively are determined.

S104 , according to the formation quality factors corresponding to the N different time periods respectively, obtain the time-dependent change of the formation quality factor of the fracturing zone in the target area, and the change is used to guide the exploitation of the oil and gas reservoir.

In this embodiment, after the formation quality factors corresponding to N different time periods are obtained, the change of the formation quality factor of the fracturing zone in the target area with time can be obtained according to the formation quality factors corresponding to the N different time periods respectively. .

Optionally, according to the change of the formation quality factor of the fracturing zone in the target area over time, for example, the smaller the Q value of the formation quality factor, the more scattered waves are scattered and the greater the attenuation, and the greater the fractures in the corresponding fracturing zone. Therefore, the scope of the fracturing zone in the target area can be determined, and then according to the scope of the fracturing zone in the target area, the exploitation of the oil and gas reservoir can be guided and the exploitation strategy of the oil and gas reservoir can be determined. Exploitation of oil and gas reservoirs.

In addition, after determining the exploitation strategy of the oil and gas reservoir, the exploitation strategy of the oil and gas reservoir can also be output. For example, the specific output mode may be that the electronic device executing the method embodiment displays the oil and gas reservoir exploitation strategy through the display screen, or the electronic device executing the method embodiment sends the oil and gas reservoir exploitation strategy to other devices.

In this embodiment, the scattered waves in the seismic waves in N different time periods in the target area are acquired, and the seismic waves are seismic waves generated by the microseismic points in the target area; according to the scattered waves, the amplitude spectra of the scattered waves in N different time periods are acquired ; According to the amplitude spectrum of scattered waves in N different time periods, determine the formation quality factors corresponding to N different time periods in the target area, where N is an integer greater than or equal to 2; According to the formation quality factors corresponding to N different time periods respectively Quality factor, obtains the change of the formation quality factor of the fracturing zone in the target area over time, and the change is used to guide the production of oil and gas reservoirs. The method uses the amplitude spectrum of the scattered wave to estimate the formation quality factor of the fracturing area. Compared with the existing technology, the amount of parameters to be obtained is reduced, the formation quality factor can be obtained accurately and quickly, and it is more helpful to guide the development of oil and gas reservoirs. .

In some embodiments, FIG. 3 is a schematic flowchart of a method for determining the change of formation quality factor in a fracturing area by using scattered waves according to another embodiment of the present application. As shown in FIG. 3 , on the basis of the embodiment shown in FIG. 1 , the method of the embodiment of the present application may include:

S301. Acquire scattered waves in seismic waves in N different time periods in the target area.

In this embodiment, for the specific implementation process of S301, reference may be made to the relevant description in the embodiment shown in FIG. 1, and details are not repeated here.

S302. Obtain the direct wave in the seismic wave.

In this embodiment, the electronic device distinguishes the received seismic waves according to the travel time of the seismic waves, and performs cutting processing on, for example, diffracted waves in the received seismic waves to obtain the direct waves in the seismic waves. Among them, the above-mentioned excision processing of, for example, diffracted waves in seismic waves belongs to the prior art, and details are not described herein again.

Optionally, the execution order of S301 and S302 is not specific, and S301 may be executed first and then S302 may be executed, or S302 may be executed first and then S301 may be executed.

S303, according to the direct wave, obtain the amplitude spectrum of the direct wave.

In this embodiment, the amplitude spectrum of the direct wave is acquired according to the direct wave in the seismic wave acquired in S302. Specifically, according to the following formula 3, the amplitude spectrum of the direct wave is obtained.

In formula 3, A represents the constant of the amplitude of the direct wave, f represents the frequency of the direct wave, n represents the symmetry index that controls the symmetry of the amplitude spectrum of the direct wave, f ₀ is the bandwidth factor that controls the amplitude spectrum bandwidth of the direct wave, S (f) represents the amplitude spectrum of the direct wave.

S304 , according to the amplitude spectrum of the direct wave and the scattered wave, acquire the amplitude spectrum of the scattered wave in N different time periods.

In this embodiment, according to the amplitude spectrum of the direct wave and the scattered wave acquired in the above S303, the amplitude spectrum of the scattered wave in N different time periods can be acquired according to formula 2. FIG. 4 is a schematic diagram of a scattered wave amplitude spectrum waveform provided by an embodiment of the present application. As shown in FIG. 4 , R ₁ to R _n in FIG. 4 respectively represent the amplitude spectrum of scattered waves at different times.

S305 , for each microseismic event e _ij in the ith time period among the N different time periods, obtain the formation quality factor Q _ij corresponding to the microseismic event e _ij according to the amplitude spectrum of the scattered waves of the microseismic event e _ij .

In this embodiment, the value of i is an integer from 1 to N, and the value of j is the number M _i of all clearly recordable microseismic events in the 1-th time period, and each microseismic event corresponds to a different scattered wave. There are Mi microseismic events in the _ith time period in the N different time periods, where _Mi represents the number of all microseismic events that can be clearly recorded in the ith time period. Using the method provided in step S102, the amplitude spectrum of the scattered wave of the microseismic event e _ij can be obtained. Therefore, according to the amplitude spectrum of the scattered wave of the microseismic event e _ij , the formation quality factor Q _ij corresponding to the microseismic event e _ij is obtained.

Optionally, the scattered waves of the microseismic event e _ij are divided into K sections, the amplitude spectrum of each scattered wave in the K section is obtained, and the corresponding formation quality factor is obtained according to the amplitude spectrum of each scattered wave; The formation quality factors corresponding to each segment of scattered waves are summed and averaged to obtain formation quality factors Q _ij corresponding to the microseismic event e _ij , where K is an integer greater than or equal to 1.

In this embodiment, after the scattered waves of the microseismic event e _ij are divided into K sections, the method provided in step S102 is used to obtain the amplitude spectrum of each scattered wave in the K sections. Therefore, according to the amplitude spectrum of each scattered wave in the K section, the corresponding formation quality factor can be obtained.

Optionally, according to the following formula 4, the formation quality factor corresponding to each segment of scattered waves is obtained.

表示微震事件e_ij的散射波的第k段的振幅谱，k的取值为1至K的整数，

表示第k段散射波相对于直达波的走时，

表示微震事件e_ij的散射波的第k段获取的地层品质因子，S_ij(f)表示第k段直达波的振幅谱，f表示散射波的频率。In formula four,

represents the amplitude spectrum of the k-th segment of the scattered wave of the microseismic event e _ij , where k is an integer from 1 to K,

represents the travel time of the k-th scattered wave relative to the direct wave,

S _ij (f) represents the amplitude spectrum of the direct wave in the k- _th segment, and f represents the frequency of the scattered wave.

After obtaining the formation quality factor corresponding to each section of the scattered wave in the K-section scattered wave according to formula 4, and then according to the following formula 5, the formation quality factor corresponding to each section of the scattered wave in the K-section scattered wave is summed and averaged to obtain The formation quality factor Q _{ij corresponding to the microseismic event e ij .}

表示微震事件e_ij的散射波的第k段获取的地层品质因子，Q_ij表示微震事件e_ij对应的地层品质因子。In formula 5, k is an integer from 1 to K,

represents the formation quality factor obtained from the k-th section of the scattered wave of the microseismic event e _ij , and Q _ij represents the formation quality factor corresponding to the microseismic event e _ij .

S306 , according to the formation quality factor Q _ij corresponding to each microseismic event e _ij in the ith time period, determine the formation quality factor Qi of the target area corresponding to the _ith time period.

In this embodiment, after obtaining the formation quality factor Q _ij corresponding to each microseismic event e _ij in the ith time period, according to the formation quality factor Q corresponding to each microseismic event e _ij in the ith time period _ij , determine the formation quality factor Q _i of the target area corresponding to the ith time period.

Optionally, the reverse time migration positioning method is used to map the formation quality factor Q _ij corresponding to each microseismic event e _ij in the M _i microseismic events to the corresponding position in the target area; The formation quality factor Q _ij is summed and averaged to determine the formation quality factor Q _i of the target area corresponding to the ith time period.

In this embodiment, there are M _i microseismic events in the ith time period. The reverse time migration positioning method is used for the scattered waves in the seismic waves obtained by the above microseismic monitoring method to obtain the location of the fracturing zone in the target area. The above-mentioned reverse time offset positioning method belongs to the prior art, and details are not described herein again. After mapping the formation quality factor Q _ij corresponding to each microseismic event e _ij in the Mi microseismic events to the corresponding position of the target area _{, sum up and average all formation quality factors Q ij mapped} to the corresponding position of the target area value, determine the formation quality factor Q _i of the target area corresponding to the ith time period.

S307 , obtaining the time-dependent change of the formation quality factor of the fracturing zone in the target area according to the formation quality factors corresponding to the N different time periods, and the change is used to guide the exploitation of the oil and gas reservoir.

In this embodiment, for the specific implementation process of S307, reference may be made to the relevant description in the embodiment shown in FIG. 1, and details are not repeated here.

Optionally, the scattered waves in the above embodiment include longitudinal waves and shear waves, and after using the reverse time migration positioning method for the scattered waves to obtain the location of the fracturing zone in the target area, the formation quality of the longitudinal waves and the shear waves can also be used. The factor difference value determines the fracturing zone range. If the difference between the formation quality factor of the longitudinal wave and the shear wave is larger, the more fracturing fluid is required in the microseismic monitoring, and the larger the fracturing range of the fracturing zone is.

In this embodiment, after obtaining the formation quality factor of the fracturing area in the target area, the location of the fracturing area in the target area is obtained by using the reverse time migration positioning method for scattered waves, and then according to the obtained target area The formation quality factor and the location of the fracturing zone in the target area are used to obtain the formation quality factor of the fracturing zone. Compared with the prior art, this method reduces the amount of parameters to obtain, and can obtain the formation quality factor accurately and quickly. Help to guide the exploitation of oil and gas reservoirs.

FIG. 5 is a schematic structural diagram of an apparatus for determining the change of formation quality factor in a fracturing area by using scattered waves according to an embodiment of the application. As shown in FIG. 5 , the apparatus for determining the change in formation quality factor in a fracturing area by using scattered waves in this embodiment is shown in FIG. 5 . 500 may include: a first obtaining module 510 , a determining module 520 , and a second obtaining module 530 .

The first acquisition module 510 is configured to acquire scattered waves in the seismic waves in N different time periods in the target area, where the seismic waves are seismic waves generated by microseismic points in the target area; and according to the scattered waves, acquire scattered waves in N different time periods the amplitude spectrum.

The determination module 520 is configured to determine formation quality factors corresponding to N different time periods of the target area respectively according to the amplitude spectra of scattered waves in N different time periods, where N is an integer greater than or equal to 2.

The second obtaining module 530 is configured to obtain the time change of the formation quality factor of the fracturing zone in the target area according to the formation quality factors corresponding to N different time periods respectively, and the change is used to guide the exploitation of the oil and gas reservoir.

Optionally, the determining module 520 is specifically used for:

For each microseismic event e _ij in the ith time period in the N different time periods, according to the amplitude spectrum of the scattered wave of the microseismic event e _ij , obtain the formation quality factor Q _ij corresponding to the microseismic event e _ij . The value is an integer from 1 to N, and the value of j is the number M _i of all microseismic events that can be clearly recorded in the ith time period; according to the formation quality factor corresponding to each microseismic event e _ij in the ith time period Q _ij , determine the formation quality factor Q _i of the target area corresponding to the ith time period.

Optionally, the determining module 520 is specifically used for:

Divide the scattered waves of the microseismic event e _ij into K sections, obtain the amplitude spectrum of each section of the scattered waves in the K section, and obtain the corresponding formation quality factor according to the amplitude spectrum of each section of the scattered waves; The corresponding formation quality factors are summed and averaged to obtain formation quality factors Q _ij corresponding to the microseismic event e _ij , where K is an integer greater than or equal to 1.

Optionally, the determining module 520 is specifically used for:

According to the following formula 1, the formation quality factor corresponding to each section of scattered wave is obtained;

表示微震事件e_ij的散射波的第k段的振幅谱，k的取值为1至K的整数，

表示第k段散射波相对于直达波的走时，

表示微震事件e_ij的散射波的第k段获取的地层品质因子，S_ij(f)表示第k段直达波的振幅谱，f表示散射波的频率。In formula 1,

represents the amplitude spectrum of the k-th segment of the scattered wave of the microseismic event e _ij , where k is an integer from 1 to K,

represents the travel time of the k-th scattered wave relative to the direct wave,

S _ij (f) represents the amplitude spectrum of the direct wave in the k- _th segment, and f represents the frequency of the scattered wave.

Optionally, the determining module 520 is specifically used for:

The reverse time migration positioning method is used to map the formation quality factor Q _{ij corresponding to each microseismic event e ij in} the Mi microseismic events to the corresponding position of the target area; all formation quality factors Q _ij mapped to the corresponding position of the target area are mapped _ij is summed and averaged to determine the formation quality factor Q _i of the target area corresponding to the ith time period.

Optionally, before acquiring the amplitude spectra of the scattered waves in N different time periods according to the scattered waves, the first acquisition module 510 is further configured to:

Obtain the direct wave in the seismic wave; according to the direct wave, obtain the amplitude spectrum of the direct wave.

According to the amplitude spectrum of the direct wave and the scattered wave, the amplitude spectrum of the scattered wave in N different time periods is obtained.

The apparatus in this embodiment can be used to implement the technical solutions of the above method embodiments, and the implementation principles and technical effects thereof are similar, and details are not described herein again.

FIG. 6 is a schematic structural diagram of an electronic device according to an embodiment of the present application. As shown in FIG. 6 , the electronic device 600 in this embodiment may include: a memory 610 and a processor 620 .

Memory 610 for storing program instructions.

The processor 620 is configured to invoke the program instructions in the memory 610 to execute:

Obtain the scattered waves of the seismic waves in N different time periods in the target area, which are the seismic waves generated by the microseismic points in the target area; according to the scattered waves, obtain the amplitude spectrum of the scattered waves in N different time periods; according to the N different time periods The amplitude spectrum of the scattered waves in the segment is used to determine the formation quality factors corresponding to N different time segments in the target area, where N is an integer greater than or equal to 2; according to the formation quality factors corresponding to N different time segments, the target area is obtained. The time-dependent variation of the formation quality factor of the inner fracturing zone is used to guide the production of oil and gas reservoirs.

Optionally, the processor 620 is specifically configured to:

For each microseismic event e _ij in the ith time period in the N different time periods, according to the amplitude spectrum of the scattered wave of the microseismic event e _ij , obtain the formation quality factor Q _ij corresponding to the microseismic event e _ij . The value is an integer from 1 to N, and the value of j is the number M _i of all microseismic events that can be clearly recorded in the ith time period; according to the formation quality factor corresponding to each microseismic event e _ij in the ith time period Q _ij , determine the formation quality factor Q _i of the target area corresponding to the ith time period.

Optionally, the processor 620 is specifically configured to:

Divide the scattered waves of the microseismic event e _ij into K sections, obtain the amplitude spectrum of each section of the scattered waves in the K section, and obtain the corresponding formation quality factor according to the amplitude spectrum of each section of the scattered waves; The corresponding formation quality factors are summed and averaged to obtain formation quality factors Q _ij corresponding to the microseismic event e _ij , where K is an integer greater than or equal to 1.

Optionally, the processor 620 is specifically configured to:

According to the following formula 1, the formation quality factor corresponding to each section of scattered wave is obtained;

表示微震事件e_ij的散射波的第k段的振幅谱，k的取值为1至K的整数，

表示第k段散射波相对于直达波的走时，

表示微震事件e_ij的散射波的第k段获取的地层品质因子，S_ij(f)表示第k段直达波的振幅谱，f表示散射波的频率。In formula 1,

represents the amplitude spectrum of the k-th segment of the scattered wave of the microseismic event e _ij , where k is an integer from 1 to K,

represents the travel time of the k-th scattered wave relative to the direct wave,

S _ij (f) represents the amplitude spectrum of the direct wave in the k- _th segment, and f represents the frequency of the scattered wave.

Optionally, the processor 620 is specifically configured to:

The reverse time migration positioning method is used to map the formation quality factor Q _{ij corresponding to each microseismic event e ij in} the Mi microseismic events to the corresponding position of the target area; all formation quality factors Q _ij mapped to the corresponding position of the target area are mapped _ij is summed and averaged to determine the formation quality factor Q _i of the target area corresponding to the ith time period.

Optionally, before acquiring the amplitude spectra of the scattered waves in N different time periods according to the scattered waves, the processor 620 is further configured to:

Obtain the direct wave in the seismic wave; according to the direct wave, obtain the amplitude spectrum of the direct wave.

According to the amplitude spectrum of the direct wave and the scattered wave, the amplitude spectrum of the scattered wave in N different time periods is obtained.

The electronic device in this embodiment can be used to implement the technical solutions of the above method embodiments, and the implementation principles and technical effects thereof are similar, which will not be repeated here.

FIG. 7 is a schematic structural diagram of an electronic device according to another embodiment of the present application. 7, electronic device 700 includes a processing component 722, which further includes one or more processors, and a memory resource represented by memory 732 for storing instructions executable by processing component 722, such as applications. An application program stored in memory 732 may include one or more modules, each corresponding to a set of instructions. In addition, the processing component 722 is configured to execute the instructions to execute the solutions in the above-described method embodiments.

The electronic device 700 may also include a power supply assembly 726 configured to perform power management of the electronic device 700, a wired or wireless network interface 750 configured to connect the electronic device 700 to a network, and an input output (I/O) interface 758 . Electronic device 700 may operate based on an operating system stored in memory 732, such as Windows Server™, Mac OS X™, Unix™, Linux™, FreeBSD™ or the like.

A non-transitory computer-readable storage medium, when an instruction in the storage medium is executed by a processor of an electronic device, enables the electronic device to execute the solutions in the foregoing method embodiments.

The present application also provides a computer program product, including a computer program, which, when executed by a processor, implements the solution of the above method for determining the variation of formation quality factor in a fracturing zone by using scattered waves.

Those of ordinary skill in the art can understand that all or part of the steps of implementing the above method embodiments may be completed by program instructions related to hardware. The aforementioned program can be stored in a computer-readable storage medium. When the program is executed, the steps including the above method embodiments are executed; and the foregoing storage medium includes: read-only memory (Read-Only Memory, ROM), random access memory (Random Access Memory, RAM), magnetic disk or Various media that can store program codes, such as optical discs.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, but not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: The technical solutions described in the foregoing embodiments can still be modified, or some or all of the technical features thereof can be equivalently replaced; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the technical solutions of the embodiments of the present application. scope.

Claims (6)

1. A method for determining the variation of formation quality factor in a fracturing zone by using scattered waves, comprising: Obtain the scattered waves in the seismic waves in N different time periods in the target area, and the seismic waves are the seismic waves generated by the microseismic points in the target area; the target area is the development position of the fractures before fracturing, and the changes of the fractures during the microseismic fracturing process The area is the change area of the formation quality factor after the cracks in the target area are expanded; obtaining the direct wave in the seismic wave; According to the direct wave, obtain the amplitude spectrum of the direct wave; obtaining, according to the amplitude spectrum of the direct wave and the scattered wave, the amplitude spectrum of the scattered wave in the N different time periods; According to the amplitude spectra of the scattered waves in the N different time periods, the formation quality factors corresponding to the N different time periods in the target area after fracture expansion are determined respectively, and according to the development position of the fracture before the fracturing and the formation quality factor in the N different time periods to locate the change area of the fracture during the microseismic fracturing process to obtain the fracture and path position corresponding to each time period of the scattered wave, where N is an integer greater than or equal to 2; According to the change of the formation quality factor corresponding to the N different time periods, the fracture and the path position are located to the correct position to obtain the fracture development area during the microseismic fracturing process, and the fracture development area is used to guide oil and gas. Tibetan mining; The determining, according to the amplitude spectra of the scattered waves in the N different time periods, the formation quality factors respectively corresponding to the N different time periods in the target area after the fracture has expanded, including: For each microseismic event e _ij in the i th time period among the N different time periods, obtain the formation quality factor corresponding to the microseismic event e _ij according to the amplitude spectrum of the scattered wave of the microseismic event e _ij Q _ij , the value of i is an integer from 1 to N, and the value of j is the number M _i of all microseismic events that can be clearly recorded in the 1-th time period; According to the formation quality factor Q _ij corresponding to each of the microseismic events e _ij in the ith time period, determine the formation quality factor Qi of the target area after the fracture corresponding to the _ith time period has expanded; The acquisition of the formation quality factor Q _ij corresponding to the microseismic event e _ij according to the amplitude spectrum of the scattered wave of the microseismic event e _ij includes: Divide the scattered waves of the microseismic event e _ij into K sections, obtain the amplitude spectrum of each section of the scattered waves in the K sections, and obtain the corresponding formation quality factor according to the amplitude spectrum of each section of the scattered waves; The formation quality factors corresponding to each of the K-section scattered waves are summed and averaged to obtain the formation quality factor Q _ij corresponding to the microseismic event e _ij , where K is an integer greater than or equal to 1; determining, according to the formation quality factor Q _ij corresponding to each of the microseismic events e _ij in the i-th time segment, the formation quality factor Q of the target area after the fractures corresponding to the i-th time segment are expanded _i , including: Using the reverse time migration positioning method to map the formation quality factor Q _ij corresponding to each microseismic event e _ij in the _Mi microseismic events to the corresponding position of the target area after the fracture has expanded; The formation quality factor Q ij of all the formation quality factors Q _ij mapped to the corresponding position of the target area after the fracture has been expanded is summed and averaged to determine the formation quality factor Q of the target area after the fracture expansion corresponding to the i-th time period _i . 2 . The method according to claim 1 , wherein the obtaining the corresponding formation quality factor according to the amplitude spectrum of each segment of scattered waves comprises: 2 . According to the following formula 1, obtain the formation quality factor corresponding to each section of the scattered wave;

In formula 1,

represents the amplitude spectrum of the k-th segment of the scattered wave of the microseismic event e _ij , where k is an integer from 1 to K,

represents the travel time of the k-th scattered wave relative to the direct wave,

represents the formation quality factor obtained from the kth segment of the scattered wave of the microseismic event e _ij , S _ij (f) represents the amplitude spectrum of the kth segment of the direct wave, and f represents the frequency of the scattered wave. 3. A device for determining the variation of formation quality factor in a fracturing area using scattered waves, characterized in that it comprises: a first acquisition module, configured to acquire scattered waves in seismic waves in N different time periods in the target area, where the seismic waves are seismic waves generated by microseismic points in the target area; and acquire the N different time periods according to the scattered waves The amplitude spectrum of the scattered wave in the segment; the target area is the development position of the fracture before the fracturing, and the change area of the fracture during the microseismic fracturing process is the change area of the formation quality factor after the expansion of the fracture in the target area; A determination module, configured to determine the formation quality factors corresponding to the N different time periods of the target area after the fracture is expanded according to the amplitude spectrum of the scattered waves in the N different time periods, and according to the The development position of the fracture before fracturing and the formation quality factor in the N different time periods locate the change region of the fracture during the microseismic fracturing process, so as to obtain the fracture and the corresponding fracture in each time period of the scattered wave. Path location, where N is an integer greater than or equal to 2; The second acquisition module is configured to locate the change of the formation quality factor corresponding to the N different time periods to the correct position through the fracture and the path position, so as to obtain the fracture development area during the microseismic fracturing process, The regionalization of the developed fractures is used to guide the exploitation of oil and gas reservoirs; Before the first acquiring module acquires the amplitude spectra of the scattered waves in N different time periods according to the scattered waves, the first acquiring module is further configured to: Obtain the direct wave in the seismic wave; according to the direct wave, obtain the amplitude spectrum of the direct wave; According to the amplitude spectrum of the direct wave and the scattered wave, obtain the amplitude spectrum of the scattered wave in N different time periods; The determining module is specifically used for: For each microseismic event e _ij in the ith time period in the N different time periods, according to the amplitude spectrum of the scattered wave of the microseismic event e _ij , obtain the formation quality factor Q _ij corresponding to the microseismic event e _ij . The value is an integer from 1 to N, and the value of j is the number M _i of all microseismic events that can be clearly recorded in the ith time period; according to the formation quality factor corresponding to each microseismic event e _ij in the ith time period Q _ij , determining the formation quality factor Q _i of the target area after fracture expansion corresponding to the ith time period; Divide the scattered waves of the microseismic event e _ij into K sections, obtain the amplitude spectrum of each section of the scattered waves in the K section, and obtain the corresponding formation quality factor according to the amplitude spectrum of each section of the scattered waves; The corresponding formation quality factors are summed and averaged to obtain formation quality factors Q _ij corresponding to the microseismic event e _ij , where K is an integer greater than or equal to 1; The reverse time migration positioning method is _{used to map the formation quality factor Q ij corresponding} to each microseismic event e _ij in the Mi microseismic events to the corresponding position of the target area after the fracture has expanded; All the formation quality factors Q _ij at the corresponding positions of the target area are summed and averaged to determine the formation quality factor Q _i of the target area after the expansion of the fracture corresponding to the i-th time period. 4. An electronic device, characterized in that, comprising: memory for storing program instructions; The processor is configured to call and execute the program instructions in the memory to execute the method for determining the variation of the formation quality factor of the fracturing zone by using the scattered wave according to claim 1 or 2. 5. A computer-readable storage medium, characterized in that, the computer storage medium stores a computer program, and when the computer program is executed by a processor, the method of determining a fracturing zone by using scattered waves according to claim 1 or 2 is realized. Methods for formation quality factor variation. 6 . A computer program medium, comprising a computer program, characterized in that, when the computer program is executed by a processor, the method according to claim 1 or 2 for determining the variation of formation quality factor in a fracturing zone by using scattered waves is implemented. 7 .

Images