Seismic inversion method and device

A technology of seismic inversion and seismic data, applied in seismology, measuring devices, seismic signal processing, etc., can solve the problem of insufficient geostatistical inversion samples, low resolution of virtual well curves, and inability to accurately reflect vertical and horizontal changes in reservoirs Features and other issues

Pending Publication Date: 2020-11-20
BC P INC CHINA NAT PETROLEUM CORP +1
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Problems solved by technology

The existing virtual well selection methods usually have the problems of low resolution of virtual well curves and insufficient ge...
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Abstract

The invention discloses a seismic inversion method and device. The method comprises the steps: acquiring seismic data of a target work area and longitudinal wave speed data and density data of a knownwell; determining a longitudinal wave impedance curve according to the longitudinal wave speed data and the density data of the known well; performing waviness difference inversion processing on thetarget work area seismic data and the longitudinal wave impedance curve to obtain wave impedance inversion volume data; determining a high-frequency pseudo-wave impedance curve corresponding to each virtual well position according to the wave impedance inversion body data and one or more preset virtual well positions; and performing seismic inversion according to the high-frequency pseudo-wave impedance curve corresponding to each virtual well position. According to the method, the problems of low virtual well curve resolution and insufficient geostatistical inversion samples in areas with fewknown wells can be solved, and the longitudinal and transverse change characteristics of the reservoir can be accurately reflected.

Application Domain

Seismic signal processingSeismology for water-logging

Technology Topic

Wave impedanceEarth quake +4

Image

  • Seismic inversion method and device
  • Seismic inversion method and device
  • Seismic inversion method and device

Examples

  • Experimental program(1)

Example Embodiment

[0024] In order to make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the following describes the embodiments of the present invention in further detail with reference to the accompanying drawings. Here, the illustrative embodiments of the present invention and the description thereof are used to explain the present invention, but not as a limitation to the present invention.
[0025] As mentioned earlier, the selection of conventional virtual wells usually has the following shortcomings: (1) The selection of virtual well positions only considers the spatial distribution of the wells and less consideration of the changes in facies; (2) The virtual well curve mostly comes from sparse pulse reaction The vertical resolution is low and cannot accurately reflect the vertical and horizontal variation characteristics of the reservoir; (3) After the selection of virtual wells, there is no effective quality control method to prove the reliability of the curve.
[0026] In order to perform seismic inversion, solve the problem of low resolution of virtual well curves and insufficient geostatistics inversion samples in areas with few known wells, and ensure accurate reflection of the vertical and horizontal change characteristics of the reservoir, the embodiment of the present invention provides a seismic Inversion methods such as figure 1 As shown, the method can include:
[0027] Step 101: Obtain seismic data of the target work area, and the longitudinal wave velocity data and density data of the known well;
[0028] Step 102: Determine a longitudinal wave impedance curve according to the longitudinal wave velocity data and density data of the known well;
[0029] Step 103: Perform volatility difference inversion processing on the seismic data and the longitudinal wave impedance curve of the target work area to obtain wave impedance inversion volume data;
[0030] Step 104: Determine a high-frequency pseudo-wave impedance curve corresponding to each virtual well position according to the wave impedance inversion volume data and one or more preset virtual well positions;
[0031] Step 105: Perform seismic inversion according to the high-frequency pseudo-wave impedance curve corresponding to each virtual well position.
[0032] by figure 1 As shown, the embodiment of the present invention obtains the seismic data of the target work area, the longitudinal wave velocity data and density data of the known well; determines the longitudinal wave impedance curve according to the longitudinal wave velocity data and density data of the known well; The seismic data and the longitudinal wave impedance curve of the target work area are used to determine the wave impedance inversion volume data; according to the wave impedance inversion volume data and one or more pre-set virtual well positions, the high frequency pseudo data corresponding to each virtual well location is determined Wave impedance curve; according to the high-frequency pseudo-wave impedance curve corresponding to each virtual well position, seismic inversion is performed. The embodiment of the present invention determines the high-frequency pseudo-wave impedance curve corresponding to each virtual well position, gets rid of the requirement for the number of wells in traditional inversion methods, and can break through the low resolution and low resolution of traditional sparse pulse inversion in areas with few known wells. The limitation of insufficient geostatistical inversion samples ensures that the vertical and horizontal changes of the reservoir are accurately reflected.
[0033] During the specific implementation, seismic data of the target work area, longitudinal wave velocity data and density data of the known wells are obtained.
[0034] During specific implementation, the longitudinal wave impedance curve is determined according to the longitudinal wave velocity data and density data of the known well.
[0035] In an embodiment, the seismic inversion method further includes: performing consistency correction on the longitudinal wave velocity data and density data of the known well; determining the longitudinal wave impedance curve according to the longitudinal wave velocity data and density data of the known well, Including: Determine the P-wave impedance curve based on the P-wave velocity data and density data of known wells after consistency correction.
[0036] In this embodiment, using the longitudinal wave velocity and density curves of known wells (two) in the target work area, based on the principle of normal distribution of the curve, the longitudinal wave velocity and density curves are respectively corrected for consistency, and the longitudinal wave velocity and density are multiplied to obtain the longitudinal wave Impedance curve. Specifically, it is preferable that a well in the target work area is a standard well, and the normal distribution characteristics of the longitudinal wave velocity of this well are analyzed; the longitudinal wave velocity of other wells is brought into the normal distribution characteristic of the longitudinal wave velocity of this well to make the longitudinal wave velocity in the standard Within the normal distribution range of the well; analyze the normal distribution characteristics of the standard well density curve; bring the density of other wells into the normal distribution characteristic of the standard well density curve to make the density within the normal distribution range of the standard well. Multiply the corrected velocity and density curve to obtain the corrected P-wave impedance curve.
[0037] During specific implementation, the volatility difference inversion processing is performed on the seismic data and the longitudinal wave impedance curve of the target work area to obtain wave impedance inversion volume data.
[0038] In the embodiment, the three-dimensional seismic data of the target work area is used, and the corrected longitudinal wave impedance curve is used as a constraint, and a high-resolution wave impedance inversion volume is obtained through waveform difference inversion.
[0039] In this embodiment, the seismic time migration data of the target work area is acquired; the seismic time migration data is used to construct the fine sequence framework of the target work area; the corrected log data of the target work area is used as a constraint and sequence framework For control, use seismic data to perform waveform difference inversion to obtain high-resolution wave impedance inversion in the target work area.
[0040] During specific implementation, the high-frequency pseudo-wave impedance curve corresponding to each virtual well position is determined according to the wave impedance inversion volume data and one or more preset virtual well positions.
[0041] In an embodiment, the position of the one or more virtual wells is preset according to the seismic geological data of the target work area, and the seismic geological data of the target work area includes: seismic data quality evaluation data, sedimentary facies zone division data, and fault distribution data. One or any combination.
[0042] During specific implementation, seismic inversion is performed according to the high-frequency pseudo-wave impedance curve corresponding to each virtual well position.
[0043] In an embodiment, performing seismic inversion according to the high-frequency pseudo-wave impedance curve corresponding to each virtual well location includes: according to the seismic data of the target work area and the high-frequency pseudo-wave impedance curve corresponding to each virtual well location, Determine the seismic correlation coefficient of each virtual well; select the virtual wells whose seismic correlation coefficient exceeds the preset value, and use the selected virtual wells to perform seismic inversion.
[0044] In the embodiment, the existing seismic geological data is reasonably used to optimize the virtual well position, and the high-frequency pseudo-wave impedance curve at multiple virtual well points is extracted in each facies zone; according to the relationship between the virtual well and the seismic correlation coefficient, the optimal The virtual well with the highest correlation coefficient in the facies zone; use high-frequency pseudo-wave impedance curves representing different facies zones to perform well-seismic coordinated inversion to obtain high-resolution phase-controlled impedance inversion.
[0045] In this embodiment, the quality of the seismic data selected by the virtual well is relatively good, and the location of the fault is avoided; the selection of the virtual well location should be carried out under the guidance of the geological results to meet the control of multiple well points in different facies zones; The high frequency pseudo wave impedance curve of the virtual well location is extracted from the resolution wave impedance inversion body. The synthetic records obtained by convolution of the extracted virtual well curves and wavelets are used to obtain the correlation coefficients between the synthetic records and the seismic traces beside the well; the seismic correlation coefficients of the virtual wells in each facies zone are sorted, and each facies zone is optimized. The well with the highest correlation coefficient is regarded as the virtual well in the facies zone. The method can be implemented by a device for phase-controlled inversion under the optimal constraints based on a high-resolution pseudo-impedance curve, or can be implemented entirely by a computer program.
[0046] A specific embodiment is given below to illustrate the specific application of the seismic inversion method in the embodiment of the present invention. In this specific embodiment, the log data of the target work area is used to perform consistency correction on the log data constituting the longitudinal wave impedance based on the normal distribution characteristics. Here as an example, the parameters that make up the longitudinal wave impedance include longitudinal wave velocity and density. The following will combine figure 2 To describe the steps of uniformly correcting the parameters constituting the longitudinal wave impedance in the specific embodiment of the present invention. As shown in step 201 to step 205, the normal distribution characteristics of the longitudinal wave velocity of the standard well are analyzed. The longitudinal wave velocity brought into other wells makes the longitudinal wave velocity within the normal distribution range, and completes the longitudinal wave velocity consistency correction. Analyze the normal distribution characteristics of the density curve of the standard well. Bring in the density of other wells so that the density is within the normal distribution range to complete the density consistency correction. Multiply the corrected velocity and density curve to obtain the corrected P-wave impedance curve. Under the constraint of the corrected P-wave impedance, use the three-dimensional seismic data of the target work area to obtain the high-resolution wave impedance inversion. The following will combine image 3 To describe the steps of obtaining a high-resolution wave impedance inversion volume in an exemplary embodiment of the present invention. As shown in step 301 to step 303, the seismic time offset data of the target work area is acquired. The seismic time migration data can be obtained by conventional methods in the field, for example, the seismic acquisition single shot data of the target work area is subjected to migration processing, which will not be repeated here. The seismic pre-stack time migration data is used for horizon tracking to construct a fine sequence framework of the target work area. The horizon can be obtained by using conventional horizon interpretation and tracking methods in the field, for example, the geological seismic reflection layer is continuously compared and tracked in the whole area, which will not be repeated here. With the corrected P-wave impedance curve as the constraint and the sequence grid as the control, the high-resolution impedance inversion body is obtained through the waveform difference inversion. Reasonably use the existing seismic geological data to optimize the location of the virtual well, and extract the high-frequency pseudo-wave impedance curve of the virtual well location from the high-resolution wave impedance inversion body. Here, the existing seismic geological data in the target work area may include the following items: seismic data quality evaluation, sedimentary facies belt division, and fault distribution. The following will combine Figure 4 To describe the steps of obtaining a high-frequency virtual well curve in an exemplary embodiment of the present invention. As shown in steps 401 to 403, the selected seismic data of the virtual well location is of relatively good quality, avoiding faults. The selection of well positions should be carried out under the guidance of sedimentary facies belts to satisfy the control of multiple well points in different facies belts. Extract the high frequency pseudo wave impedance curve of the virtual well location from the high resolution wave impedance inversion volume. The virtual well curve is optimized through the seismic correlation coefficient. The following will combine Figure 5 To describe the steps of obtaining a preferred virtual well curve in an exemplary embodiment of the present invention. As shown in step 501 to step 502, the synthetic record obtained by convolution of the extracted virtual well curve and wavelet is used to obtain the correlation coefficient between the synthetic record and the seismic trace beside the well. The seismic correlation coefficients of virtual wells in each facies zone are sorted, and the well with the highest correlation coefficient in each facies zone is selected as the virtual well in the facies zone. The high-frequency pseudo-wave impedance curves representing different phase zones are used to perform well-seismic coordinated inversion to obtain high-resolution phase-controlled impedance inversion. Although the present invention has been specifically shown and described with reference to its exemplary embodiments, those skilled in the art should understand that the forms and details can be made without departing from the spirit and scope of the present invention as defined by the claims. Various changes on.
[0047] Based on the same inventive concept, embodiments of the present invention also provide a seismic inversion device, as described in the following embodiments. Since these problem-solving principles are similar to the seismic inversion method, the implementation of the device can refer to the implementation of the method, and the repetition will not be repeated.
[0048] Image 6 It is a structural diagram of the seismic inversion device in the embodiment of the present invention, such as Image 6 As shown, the device includes:
[0049] The data obtaining module 601 is used to obtain seismic data of the target work area, longitudinal wave velocity data and density data of known wells;
[0050] The P-wave impedance curve determination module 602 is used to determine the P-wave impedance curve according to the P-wave velocity data and density data of the known well;
[0051] The wave impedance inversion volume data determination module 603 is configured to perform wave property difference inversion processing on the seismic data and the longitudinal wave impedance curve of the target work area to obtain the wave impedance inversion volume data;
[0052] The high-frequency pseudo-wave impedance curve determination module 604 is configured to determine the high-frequency pseudo-wave impedance curve corresponding to each virtual well position according to the impedance inversion volume data and one or more preset virtual well positions;
[0053] The seismic inversion module 605 is configured to perform seismic inversion according to the high-frequency pseudo-wave impedance curve corresponding to each virtual well position.
[0054] In one embodiment, the position of the one or more virtual wells is preset according to the seismic geological data of the target work area, and the seismic geological data of the target work area includes: seismic data quality evaluation data, sedimentary facies zone division data, and fault distribution data. One or any combination.
[0055] In one embodiment, such as Figure 7 As shown, Image 6 The seismic inversion equipment also includes:
[0056] The correction module 606 is used to perform consistency correction on the longitudinal wave velocity data and density data of the known well;
[0057] The longitudinal wave impedance curve determination module 602 is further configured to determine the longitudinal wave impedance curve according to the longitudinal wave velocity data and density data of the known well after consistency correction.
[0058] In an embodiment, the seismic inversion module 605 is further used for:
[0059] Determine the seismic correlation coefficient of each virtual well according to the seismic data of the target work area and the high-frequency pseudo-wave impedance curve corresponding to each virtual well position;
[0060] Select virtual wells whose well-seismic correlation coefficient exceeds the preset value, and use the selected virtual wells to perform seismic inversion.
[0061] To sum up, the embodiment of the present invention obtains the seismic data of the target work area, the longitudinal wave velocity data and density data of the known well; determines the longitudinal wave impedance curve according to the longitudinal wave velocity data and density data of the known well; The seismic data and the longitudinal wave impedance curve in the work area are subjected to volatility difference inversion processing to obtain wave impedance inversion volume data; each virtual well is determined according to the wave impedance inversion volume data and one or more preset virtual well positions High-frequency pseudo-wave impedance curve corresponding to the position; seismic inversion is performed according to the high-frequency pseudo-wave impedance curve corresponding to each virtual well position. The embodiment of the present invention determines the high-frequency pseudo-wave impedance curve corresponding to each virtual well position, gets rid of the requirement for the number of wells in traditional inversion methods, and can break through the low resolution and low resolution of traditional sparse pulse inversion in areas with few known wells. The limitation of insufficient geostatistical inversion samples ensures that the vertical and horizontal changes of the reservoir are accurately reflected.
[0062] Those skilled in the art should understand that the embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present invention may adopt 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 codes.
[0063] 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, and 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 the processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing equipment to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing equipment are generated In the process Figure one Process or multiple processes and/or boxes Figure one A device with functions specified in a block or multiple blocks.
[0064] These computer program instructions can also be stored in a computer-readable memory that can guide a computer or other programmable data processing equipment to work in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture including the instruction device. The device is implemented in the process Figure one Process or multiple processes and/or boxes Figure one Function specified in a box or multiple boxes.
[0065] These computer program instructions can also be loaded on a computer or other programmable data processing equipment, so that a series of operation steps are executed on the computer or other programmable equipment to produce computer-implemented processing, so as to execute on the computer or other programmable equipment. Instructions are provided to implement the process Figure one Process or multiple processes and/or boxes Figure one Steps of functions specified in a box or multiple boxes.
[0066] The specific embodiments described above further describe the purpose, technical solutions and beneficial effects of the present invention in further detail. It should be understood that the above descriptions are only specific embodiments of the present invention and are not intended to limit the scope of the present invention. The protection scope, any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

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