Seismic data processing method and device

Abstract

The present invention discloses a method and device for processing seismic data, the method comprising: obtaining seismic data of a preset work area, and establishing a formation absorption attenuation model using the seismic data; performing frequency compensation on the seismic data using the formation absorption attenuation model; performing surface consistency deconvolution processing on the frequency-compensated seismic data; and performing statistical wavelet deconvolution on the seismic data after surface consistency deconvolution processing. The present invention can not only improve the energy of weak reflection signals between coal seams, but also finely depict the internal reflection characteristics of thin gas-bearing sandstone reservoirs in the subsequent process, thus ensuring the transformation of oil and gas development to the exploration of high-precision lithologic oil and gas reservoirs.

Description

Technical Field

[0001] The present invention relates to the technical field of oil and gas exploration, and in particular to a seismic data processing method and device. Background Art

[0002] With the increase in demand for oil and gas energy, the focus of oil and gas development has gradually shifted from structural oil and gas reservoirs to lithological oil and gas reservoirs, which has put forward higher requirements for seismic data processing technology. In particular, some coal-bearing inter-stratum sandstone reservoirs are developed, the distribution of traps is controlled by the degree of sand body development, and there are industrial gas layers, which have great exploration potential.

[0003] In the process of seismic data processing, the existing technology usually adopts the surface consistency deconvolution method to improve the energy of each superimposed stratum of the coal measure and the resolution of seismic data to achieve the characterization of the coal seam. However, due to the interference of the strong seismic reflection characteristics of the coal-measure strata and the complexity and variability of the weak reflection thin reservoir of the river sand body between two adjacent coal-measure strata, the existing technology cannot accurately characterize the internal reflection characteristics of the thin gas-bearing sandstone reservoir, which further limits the transformation of oil and gas development to the exploration of high-precision lithological oil and gas reservoirs. Summary of the invention

[0004] An embodiment of the present invention provides a seismic data processing method for finely depicting the internal reflection characteristics of a thin gas-bearing sandstone reservoir, the method comprising:

[0005] Obtain seismic data of the preset work area and use the seismic data to establish a formation absorption attenuation model;

[0006] Performing frequency compensation on seismic data using the formation absorption attenuation model;

[0007] Perform surface consistent deconvolution on the frequency compensated seismic data;

[0008] Statistical wavelet deconvolution is performed on the seismic data after surface consistent deconvolution.

[0009] Optionally, seismic data of a preset work area is obtained, and a formation absorption attenuation model is established using the seismic data, including:

[0010] Obtain the seismic data of the preset work area and calculate the formation quality factor Q based on the seismic data. The calculation formula is as follows:

[0011]

[0012] Among them, α(m -1 ) is the formation absorption coefficient, ν (m / s) is the propagation speed of seismic waves, and f (Hz) is the frequency;

[0013] The formation absorption attenuation model is established using the formation quality factor Q.

[0014] Optionally, the frequency compensation includes: phase compensation and amplitude compensation.

[0015] Optionally, statistical wavelet deconvolution is performed on the seismic data after surface consistency deconvolution, including:

[0016] Analyzing the frequency of the seismic data after surface consistent deconvolution, and calculating Yu wavelet in combination with the well logging information in the seismic data;

[0017] The Yu wavelet is used as the expected output for statistical wavelet deconvolution.

[0018] The embodiment of the present invention further provides a seismic data processing device for finely depicting the internal reflection characteristics of a thin gas-bearing sandstone reservoir, the device comprising:

[0019] A data acquisition module is used to acquire seismic data of a preset work area and establish a formation absorption attenuation model using the seismic data;

[0020] A frequency compensation module, used for performing frequency compensation on seismic data using the formation absorption attenuation model;

[0021] A first data processing module, used for performing surface consistency deconvolution processing on the frequency-compensated seismic data;

[0022] The second data processing module is used to perform statistical wavelet deconvolution on the seismic data after surface consistency deconvolution processing.

[0023] Optionally, the data acquisition module is further used to:

[0024] Obtain the seismic data of the preset work area and calculate the formation quality factor Q based on the seismic data. The calculation formula is as follows:

[0025]

[0026] Among them, α(m -1 ) is the formation absorption coefficient, ν (m / s) is the propagation speed of seismic waves, and f (Hz) is the frequency;

[0027] The formation absorption attenuation model is established using the formation quality factor Q.

[0028] Optionally, the frequency compensation includes: phase compensation and amplitude compensation.

[0029] Optionally, the second data processing module is further used for:

[0030] Analyzing the frequency of the seismic data after surface consistent deconvolution, and calculating Yu wavelet in combination with the well logging information in the seismic data;

[0031] The Yu wavelet is used as the expected output for statistical wavelet deconvolution.

[0032] An embodiment of the present invention further provides a computer device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the above method when executing the computer program.

[0033] An embodiment of the present invention further provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program for executing the above method.

[0034] In the embodiment of the present invention, by acquiring the seismic data of the preset work area, and using the seismic data to establish a formation absorption and attenuation model, and using the formation absorption and attenuation model to perform frequency compensation on the seismic data, the absorption and attenuation effect of the formation on the seismic wave is eliminated, and the shielding effect of the strong reflection signal of the coal seam on the weak reflection signal between layers is weakened. By performing surface consistency deconvolution processing on the seismic data after frequency compensation, the spatial difference of the seismic data is eliminated, and the spatial wavelet consistency of the reflection signal of the coal seam and the thin sandstone between layers is improved. By performing statistical wavelet deconvolution on the seismic data after surface consistency deconvolution processing, not only can the energy of the weak reflection signal between coal seams be improved, but also the internal reflection characteristics of the thin gas-bearing sandstone reservoir can be finely portrayed in the subsequent process, ensuring the transformation of oil and gas development to the exploration of high-precision lithological oil and gas reservoirs. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the prior art descriptions. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work. In the drawings:

[0036] Figure 1 A schematic diagram of a flow chart of a seismic data processing method according to an embodiment of the present invention;

[0037] Figure 2 A schematic diagram of the structure of a seismic data processing device in an embodiment of the present invention;

[0038] Figure 3 A specific example diagram of a formation absorption attenuation model in an embodiment of the present invention;

[0039] Figure 4a This is an example diagram of a seismic profile before surface consistency deconvolution is performed in a preset work area in an embodiment of the present invention;

[0040] Figure 4b This is an example diagram of a seismic profile after surface consistency deconvolution is performed in a preset work area in an embodiment of the present invention;

[0041] Figure 5 A specific example diagram of a seismic profile of a preset work area in an embodiment of the present invention;

[0042] Figure 6 It is a synthetic seismic record of a preset working area in an embodiment of the present invention. DETAILED DESCRIPTION

[0043] To make the purpose, technical solution and advantages of the embodiments of the present invention more clear, the embodiments of the present invention are further described in detail below in conjunction with the accompanying drawings. Here, the exemplary embodiments of the present invention and their descriptions are used to explain the present invention, but are not intended to limit the present invention.

[0044] It should be noted that some coal-bearing inter-stratum sandstone reservoirs are developed, the distribution of traps is controlled by the degree of sand body development, there are industrial gas layers, and the exploration potential is great, but the sand bodies between coal seams are thin and stacked vertically and horizontally, with frequent phase changes, strong heterogeneity, small difference in wave impedance between sand bodies and surrounding rocks, and weak reflection energy. The strong reflection signal of the coal seam often causes a certain degree of shielding effect on the weak reflection signal of the thin sand layer between two adjacent coal seams.

[0045] The embodiment of the present invention provides a method for processing seismic data. Figure 1 As shown, the method includes:

[0046] Step 101: Obtain seismic data of a preset work area, and use the seismic data to establish a formation absorption attenuation model.

[0047] Step 102: Perform frequency compensation on seismic data using the formation absorption attenuation model.

[0048] Step 103: Perform surface consistent deconvolution processing on the frequency compensated seismic data.

[0049] Step 104: Perform statistical wavelet deconvolution on the seismic data after surface consistency deconvolution processing.

[0050] By the attached Figure 1It can be seen that the seismic data processing method provided by the embodiment of the present invention obtains seismic data of a preset work area, establishes a formation absorption attenuation model using the seismic data, and performs frequency compensation on the seismic data using the formation absorption attenuation model, thereby eliminating the absorption and attenuation effect of the formation on seismic waves, and weakening the shielding effect of the strong reflection signal of the coal seam on the weak reflection signal between layers (i.e., the thin sandstone between two coal seams). By performing surface consistency deconvolution processing on the seismic data after frequency compensation, the spatial difference of the seismic data is eliminated, and the spatial wavelet consistency of the reflection signal of the coal seam and the thin sandstone between layers is improved. By performing statistical wavelet deconvolution on the seismic data after surface consistency deconvolution processing, not only can the energy of the weak reflection signal between coal seams be improved, but also the internal reflection characteristics of the thin gas-bearing sandstone reservoir can be finely portrayed in the subsequent process, ensuring the transformation of oil and gas development to the exploration of high-precision lithological oil and gas reservoirs.

[0051] In one embodiment, step 101 includes:

[0052] Obtain the seismic data of the preset work area and calculate the formation quality factor Q based on the seismic data. The calculation formula is as follows:

[0053]

[0054] Among them, α(m -1 ) is the formation absorption coefficient, ν (m / s) is the propagation speed of seismic waves, and f (Hz) is the frequency;

[0055] The formation absorption attenuation model is established using the formation quality factor Q.

[0056] During the specific implementation, the distribution of geological strata and lithology in the preset work area is investigated, and the absorption coefficient α (m -1 ), and according to the formula Calculate the Q value corresponding to time T. The formation quality factor Q here can be understood as the ratio of stored energy to lost energy within a wavelength λ.

[0057] For the specific formation absorption attenuation model, please refer to the attached Figure 3 , attached Figure 3 This is a formation absorption attenuation model established based on the seismic data of the preset work area. It can be seen that starting from about 600ms, the Q value shows a significant increasing trend with the increase of time; and starting from 700ms, the Q value fluctuates violently, indicating that the lithology of this section changes dramatically and the degree of attenuation of the reflected energy due to formation absorption varies greatly.

[0058] In one embodiment, frequency compensation includes phase compensation and amplitude compensation.

[0059] Step 102 specifically includes:

[0060] First, phase scan the seismic data and calibrate the layers according to the well logging curve to determine the phase difference between the seismic data and the well seismic records. Then, compare the well seismic traces with the well synthetic seismic records of different frequencies to determine the main frequency of the reflection signal corresponding to the different lithologies of the target layer. Figure 6 The synthetic seismic records of the wells extracted by Ricker wavelets of different main frequencies for the preset work area show that the main coal seam and the thin sandstone reservoir between the coal seams can be better portrayed above 60HZ. Finally, the seismic data is amplitude compensated and phase compensated according to the phase difference and main frequency information, as well as the formation quality factor obtained in step 101.

[0061] The above Q value is used to calculate the amplitude spectrum of frequency f at time t, and the formula is:

[0062]

[0063] Using Hilbert transform, the phase spectrum is obtained according to the amplitude spectrum B(f), and the formula is as follows:

[0064]

[0065] Here, H(|f|) represents the Hilbert transform of |f|.

[0066] The complex spectrum of the entire filtering process is The frequency response of the inverse Q filter with respect to the travel time t is obtained as:

[0067]

[0068] After convolution, the seismic data Y(t) after inverse Q filtering is obtained, and its formula is as follows:

[0069] Y(t)=∫X(f)Q -1 (f,t)e i2πft df

[0070] Where X(f) is the spectrum of the inverse Q-filtered input data.

[0071] Attached Figure 4a This is the effect diagram of the existing technology application. It can be seen that the consistency of the strong reflection of the coal seam is good. Figure 4b The effect of applying step 101, step 102, and step 103 in series in the present invention is that not only the consistency of strong reflection of coal seams is improved on the profile, but also the consistency of weak reflection signals between coal seams is significantly improved. Therefore, the present invention can not only effectively eliminate the absorption and attenuation effect of the stratum on seismic waves, but also weaken the shielding effect of strong reflection of coal seams on weak reflection signals between layers, thereby ensuring that the sub-wave consistency is improved within a wider dominant frequency band.

[0072] In one embodiment, step 104 includes:

[0073] Analyzing the frequency of the seismic data after surface consistent deconvolution, and calculating Yu wavelet in combination with the well logging information in the seismic data;

[0074] The Yu wavelet is used as the expected output for statistical wavelet deconvolution.

[0075] In the specific implementation, the frequency of the seismic data after surface consistency deconvolution is analyzed, and the dominant frequency band and effective bandwidth of the coal seam and interlayer thin sand layer are determined in combination with the logging information. The value p is assigned as the lowest effective frequency and q is assigned as the highest effective frequency. The Yu wavelet is calculated, and the formula is as follows:

[0076]

[0077] Among them, R(f) represents the Ricker wavelet, and its formula is

[0078]

[0079] f is the peak frequency of the Ricker wavelet.

[0080] The seismic data after surface consistent deconvolution are subjected to statistical wavelet deconvolution with Yu's wavelet as the expected output.

[0081] The imaging effect after statistical wavelet deconvolution of the preset work area can be found in the attached Figure 5 ,It can be seen that the energy of weak reflection signals between coal seams is effectively improved.

[0082] Based on the same inventive concept, a seismic data processing device is also provided in the embodiments of the present invention, as described in the following embodiments. Since the principle of solving the problem by the seismic data processing device is similar to that of the seismic data processing method, the implementation of the seismic data processing device can refer to the implementation of the seismic data processing method, and the repeated parts are not repeated. As used below, the term "unit" or "module" can be a combination of software and / or hardware that implements a predetermined function. Although the device described in the following embodiments is preferably implemented in software, the implementation of hardware, or a combination of software and hardware, is also possible and conceived.

[0083] The embodiment of the present invention provides a seismic data processing device, as shown in the attached Figure 2 As shown, the device comprises:

[0084] The data acquisition module 201 is used to acquire seismic data of a preset work area and establish a formation absorption attenuation model using the seismic data;

[0085] A frequency compensation module 202, used to perform frequency compensation on seismic data using the formation absorption attenuation model;

[0086] The first data processing module 203 is used to perform surface consistency deconvolution processing on the frequency-compensated seismic data;

[0087] The second data processing module 204 is used to perform statistical wavelet deconvolution on the seismic data after the surface consistency deconvolution processing.

[0088] In the embodiment of the present invention, the data acquisition module 201 is further used for:

[0089] Obtain the seismic data of the preset work area and calculate the formation quality factor Q based on the seismic data. The calculation formula is as follows:

[0090]

[0091] Among them, α(m -1 ) is the formation absorption coefficient, ν (m / s) is the propagation speed of seismic waves, and f (Hz) is the frequency;

[0092] The formation absorption attenuation model is established using the formation quality factor Q.

[0093] In the embodiment of the present invention, the frequency compensation includes: phase compensation and amplitude compensation.

[0094] In this embodiment of the present invention, the second data processing module 204 is further configured to:

[0095] Analyzing the frequency of the seismic data after surface consistent deconvolution, and calculating Yu wavelet in combination with the well logging information in the seismic data;

[0096] The Yu wavelet is used as the expected output for statistical wavelet deconvolution.

[0097] An embodiment of the present invention further provides a computer device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the above method when executing the computer program.

[0098] An embodiment of the present invention further provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program for executing the above method.

[0099] The seismic data processing method provided by the embodiment of the present invention obtains seismic data of a preset work area, establishes a formation absorption and attenuation model using the seismic data, and performs frequency compensation on the seismic data using the formation absorption and attenuation model, thereby eliminating the absorption and attenuation effect of the formation on seismic waves, and weakening the shielding effect of the strong reflection signal of the coal seam on the weak reflection signal between layers (i.e., the thin sandstone between two coal seams). By performing surface consistency deconvolution processing on the seismic data after frequency compensation, the spatial difference of the seismic data is eliminated, and the spatial wavelet consistency of the reflection signal of the coal seam and the thin sandstone between layers is improved. By performing statistical wavelet deconvolution on the seismic data after surface consistency deconvolution processing, not only can the energy of the weak reflection signal between coal seams be improved, but also the internal reflection characteristics of the thin gas-bearing sandstone reservoir can be finely portrayed in the subsequent process, ensuring the transformation of oil and gas development to the exploration of high-precision lithological oil and gas reservoirs.

[0100] In the embodiment, the present invention realizes the close integration of seismic data and logging data, thus ensuring the amplitude preservation and fidelity of the data during the implementation of the method, so that the final results are more in line with the actual formation heterogeneity characteristics and the multi-layer overlapping characteristics of the main target layer segments.

[0101] Those skilled in the art will appreciate that embodiments of the present invention may be provided as methods, systems, or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0102] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0103] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0104] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0105] The specific embodiments described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for processing seismic data of thin gas-bearing sandstone reservoirs, characterized in that: include: Obtain seismic data of the preset work area and use the seismic data to establish a formation absorption attenuation model; Performing frequency compensation on seismic data using the formation absorption attenuation model; Perform surface consistent deconvolution on the frequency compensated seismic data; Perform statistical wavelet deconvolution on the seismic data after surface consistent deconvolution; Among them, statistical wavelet deconvolution is performed on the seismic data after surface consistency deconvolution, including: The frequency of seismic data after surface consistent deconvolution is analyzed, and combined with logging information, the dominant frequency band and effective bandwidth of coal seams and interlayer thin sand layers are determined, and p is assigned as the lowest effective frequency and q as the highest effective frequency, and Yu's sub-wave is calculated. The formula is as follows: Where R(f, t) represents the Ricker wavelet, and its formula is: f is the peak frequency of the Ricker wavelet; Perform statistical wavelet deconvolution on the seismic data after surface consistency deconvolution with Yu wavelet as the expected output; The seismic data of the preset work area is obtained, and the formation absorption attenuation model is established using the seismic data, including: Obtain the seismic data of the preset work area and calculate the formation quality factor Q based on the seismic data. The calculation formula is as follows: Among them, α is the formation absorption coefficient, ν is the propagation speed of seismic waves, and h is the frequency; The formation absorption attenuation model is established using the formation quality factor Q; Among them, the frequency compensation of seismic data is performed using the formation absorption attenuation model, including: phase scanning of the seismic data, and layer calibration according to the logging curve to determine the phase difference between the seismic data and the well seismic record; comparing the wellside seismic trace with the well synthetic seismic records of different frequencies to determine the main frequency of the reflection signal corresponding to different lithologies of the target layer; amplitude compensation and phase compensation of the seismic data are performed according to the phase difference and main frequency information, as well as the formation quality factor Q.

2. A seismic data processing device for thin gas-bearing sandstone reservoirs, characterized in that: include: A data acquisition module is used to acquire seismic data of a preset work area and establish a formation absorption attenuation model using the seismic data; The frequency compensation module is used to perform frequency compensation on seismic data using the formation absorption attenuation model; including: performing phase scanning on the seismic data, and calibrating the layer position according to the well logging curve to determine the phase difference between the seismic data and the well seismic record; comparing the wellside seismic trace with the well synthetic seismic records of different frequencies to determine the main frequency of the reflection signal corresponding to different lithologies of the target layer; performing amplitude compensation and phase compensation on the seismic data according to the phase difference and main frequency information, as well as the formation quality factor Q; A first data processing module, used for performing surface consistency deconvolution processing on the frequency-compensated seismic data; The second data processing module is used to perform statistical wavelet deconvolution on the seismic data after surface consistency deconvolution processing; The second data processing module is further used for: The frequency of seismic data after surface consistent deconvolution is analyzed, and combined with logging information, the dominant frequency band and effective bandwidth of coal seams and interlayer thin sand layers are determined, and p is assigned as the lowest effective frequency and q as the highest effective frequency, and Yu's sub-wave is calculated. The formula is as follows: Among them, R(f, t) represents the Ricker wavelet, and its formula is f is the peak frequency of the Ricker wavelet; Perform statistical wavelet deconvolution on the seismic data after surface consistency deconvolution with Yu wavelet as the expected output; The data acquisition module is further used to: Obtain the seismic data of the preset work area and calculate the formation quality factor Q based on the seismic data. The calculation formula is as follows: Among them, α is the formation absorption coefficient, ν is the propagation speed of seismic waves, and h is the frequency; The formation absorption attenuation model is established using the formation quality factor Q.

3. A computer device comprising a memory, a processor and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the method of claim 1 is implemented.

4. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the method of claim 1 is implemented.

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