A seismic amplitude quality control method based on multi-well logging data

Abstract

The present invention relates to a seismic amplitude quality control method based on multiple well logging data. It includes: a target well selection step, which is used to select a well whose logging data meets preset conditions as a target well; a spherical compensation step, which is used to perform spherical diffusion compensation on the target well data; a single well quality control step, which is used to compare the shallow, medium and deep amplitude trends of seismic data at the well point location, and constrain the vertical amplitude recovery effect of the well bypass; a well-joined quality control step, which is used to quality control the amplitude recovery effect of multiple well points and wells in a well-joined manner. Therefore, this method is based on the single well quality control results, and uses the synthetic seismic recording data of multiple wells. This method can complete the vertical and lateral amplitude trend quality control of the data.

Description

Technical Field

[0001] The invention relates to a seismic amplitude quality control method, belonging to the technical field of geological exploration, and specifically to a seismic amplitude quality control method based on multiple well logging data. Background Art

[0002] The goal of seismic exploration has gradually shifted from large-scale structural interpretation to small-scale lithology identification. This requires that the amplitude information in the seismic data can truly and effectively reflect the rock characteristics. The key lies in the protection and compensation of the amplitude information of the effective wave during the seismic data processing. However, in the current data processing process, the processing effect mainly depends on experience. There is no measurement scale to evaluate the data, and the compensation effect is difficult to guarantee. For example, comparing the appearance and amplitude attenuation curve of a single shot before and after amplitude recovery to see whether the amplitude is compensated in place, the judgment criteria are relatively subjective and one-sided.

[0003] In order to overcome such defects, the existing technology has proposed well-controlled seismic data processing technology, which uses well logging, VSP and other well data to analyze and quality control seismic data, in order to make up for the lack of understanding in data processing and meet the needs of geological analysis and oil and gas development for high-precision lithological interpretation of seismic data. On this basis, well-controlled amplitude compensation, well-controlled deconvolution, well-controlled anti-Q compensation and other technologies have been further proposed.

[0004] However, current well control processing technology mainly uses well information to perform quality control on data from well bypasses. Data from well points cannot be compared using the same standard, and data far from the well points cannot be quality controlled either. Summary of the invention

[0005] A brief summary of one or more aspects is given below to provide a basic understanding of these aspects. This summary is not an exhaustive overview of all conceived aspects, and is neither intended to identify the key or critical elements of all aspects nor to define the scope of any or all aspects. Its only purpose is to give some concepts of one or more aspects in a simplified form as a prelude to a more detailed description that will be given later.

[0006] The main purpose of the present invention is to solve the problems existing in the prior art that the amplitude recovery effect of the well bypass is controlled by using single well data, and it is unable to cope with the parameter differences between multiple wells and unable to constrain the data recovery effect far away from the well point. A seismic amplitude quality control method based on multiple logging data is proposed. This method controls the well bypass based on the current well quality control, and uses multi-well data to establish a geological model to achieve the purpose of quality control of the amplitude recovery effect of inter-well data.

[0007] To solve the above problems, the solution of the present invention is:

[0008] A seismic amplitude quality control method based on multiple well logging data, comprising:

[0009] A target well selection step is used to select a well whose logging data meets a preset condition as a target well;

[0010] A spherical compensation step, for performing spherical diffusion compensation on the target well data;

[0011] The single well quality control step is used to compare the shallow, medium and deep amplitude trends of the seismic data at the well point location and constrain the vertical amplitude recovery effect of the well bypass;

[0012] The well-linked quality control step is used to quality control the amplitude recovery effect of multiple well points and between wells in the well-linked mode.

[0013] Preferably, the above-mentioned seismic amplitude quality control method based on multiple well logging data further includes:

[0014] The well curve correction step is used to perform environmental, outlier and normalization processing on seismic data.

[0015] Preferably, in the above-mentioned seismic amplitude quality control method based on multiple well logging data, in the target well selection step, the preset conditions for selecting the target well include one or more of the following conditions:

[0016] (1) The correlation coefficient between the synthetic seismic record and the well bypass reaches the preset value;

[0017] (2) The well is located inside the exploration area and the seismic data has full coverage;

[0018] (3) The underground structure at the well location is simple and has a good signal-to-noise ratio.

[0019] Preferably, in the above-mentioned seismic amplitude quality control method based on multiple well logging data, in the spherical compensation step, spherical compensation is performed using a time velocity compensation method based on the following formula:

[0020]

[0021] Where: A(0) is the amplitude value before recovery, t is the sampling time, A(t) is the amplitude after recovery, v0 is the speed at time 0; v(t) is the speed at the current time t, which is provided by the database.

[0022] Preferably, in the above-mentioned seismic amplitude quality control method based on multiple well logging data, in the spherical compensation step, spherical compensation is performed by using an exponential function compensation method based on the following formula:

[0023]

[0024] Where: A is the amplitude value, t is the sampling time (milliseconds), and n is the exponential value that defines the compensation function.

[0025] Preferably, in the above-mentioned seismic amplitude quality control method based on multiple well logging data, the single well quality control step includes the following sub-steps:

[0026] Well seismic calibration sub-step, using the P-wave velocity and density of the target well to obtain synthetic seismic records and perform time-depth conversion and layer calibration;

[0027] Amplitude recovery sub-step, performing amplitude compensation on synthetic seismic data;

[0028] The amplitude energy curve comparison sub-step calculates the amplitude energy curves of the synthetic seismic record trace and the well side trace, and quality controls whether the energy trend of the energy curve from shallow to deep is compensated in place;

[0029] The regional amplitude compensation sub-step compensates for the differences caused by regional lithology differences.

[0030] Preferably, in the above-mentioned seismic amplitude quality control method based on multiple well logging data, in the regional amplitude compensation sub-step, the energy compensation factor of the regional lithology is obtained based on the following formula:

[0031]

[0032] E k is the kth compensation factor, i is time, j is the channel number, A is the amplitude, t is the window time, and N is the total number of channels.

[0033] Preferably, in the above-mentioned seismic amplitude quality control method based on multiple well logging data, the well joint quality control step includes the following sub-steps:

[0034] The horizon division sub-step interprets and tracks the horizons in the seismic data far from the well based on the well calibration results;

[0035] Convert the horizons tracked on the seismic profile to the depth domain and build a quality control model profile corresponding to the well-linked profile in combination with the velocity and density curves of the well;

[0036] The wave group characteristic comparison sub-step compares the wave group characteristics and energy trends of the well-linked section of the seismic data and the model section based on the quality control model section obtained by simulation as a scale;

[0037] The amplitude compensation sub-step uses the space-variable compensation parameter value to compensate the vertical amplitude of the multi-well data.

[0038] Therefore, compared with the prior art, the present invention has the following advantages:

[0039] 1. Methods Using synthetic seismic data from multiple wells, we can perform multi-point vertical amplitude trend quality control on the three-dimensional data volume;

[0040] 2. The method is based on the quality control results of a single well, and the spherical diffusion parameter n is changed to make the amplitude compensation effect more consistent with the actual geological conditions;

[0041] 3. Methods: Use multiple wells to make a well-connected geological model section, and use it as a ruler to control the quality of data far away from the well points;

[0042] 4. The method can complete the quality control of the vertical and horizontal amplitude trends of the data. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] The accompanying drawings, which are incorporated herein and form a part of the specification, illustrate embodiments of the present invention and, together with the description, further serve to explain the principles of the invention and to enable one skilled in the art to make and use the present disclosure.

[0044] Figure 1 The amplitude quality control method in the embodiment of the present invention is illustrated;

[0045] Figure 2 A schematic diagram of well locations in an embodiment of the present invention is illustrated;

[0046] FIG3 illustrates a logic flow chart of a monitoring processing device in an embodiment of the present invention;

[0047] FIG. 4 illustrates a schematic diagram of amplitude compensation quality control under well-linking constraints in an embodiment of the present invention.

[0048] Embodiments of the present invention will be described with reference to the accompanying drawings. DETAILED DESCRIPTION

[0049] Example

[0050] This embodiment first provides a seismic amplitude quality control method based on multiple well logging data, including the following steps:

[0051] Step 1: Well curve correction

[0052] Well curves are used as a scale in the process of well control to evaluate the processing effect of seismic data. Therefore, the accuracy of well data is the premise of all quality control. Before using well data, it is necessary to correct the environment, outliers and normalization of the data to eliminate the differences caused by non-geological factors.

[0053] Step 2: Target well selection

[0054] Since the quality of logging data varies, if problematic logging or unrepresentative wells are introduced into the well control process, quality control will have a counterproductive effect. Therefore, wells that can be used for quality control need to be screened according to the following three conditions:

[0055] ① The synthetic seismic record has a correlation coefficient of more than 0.6 with the well bypass;

[0056] ② The well is located inside the exploration area and the seismic data has full coverage times;

[0057] ③The underground structure where the well is located is simple and the signal-to-noise ratio is good.

[0058] Step 3: Amplitude compensation

[0059] Since the amplitude of seismic data will decay as the propagation distance increases after the seismic wave is excited, the first step in recovering the amplitude of seismic data is to perform spherical diffusion compensation. Spherical diffusion compensation can be divided into two categories: time-velocity pair compensation and exponential function compensation.

[0060] ①Time and speed compensation method

[0061]

[0062] The advantage of this method is that it uses velocity as a parameter, and seismic velocity is derived from velocity analysis, so velocity is a volume data, which is variable in space and more reasonable in theory. However, once the velocity is determined, the recovery effect cannot be changed.

[0063] ②Exponential function compensation method

[0064]

[0065] Where: A is the amplitude value, t is the sampling time (milliseconds), and n is the exponential value that defines the compensation function.

[0066] The advantage of this method is that the restoration effect can be controlled by the parameter n to control the relative relationship of the amplitudes of shallow, medium, deep and near, medium and far. The disadvantage is that only one parameter can be selected and it cannot cope with complex geological conditions.

[0067] Step 4: Single Well Quality Control

[0068] The single well amplitude constraint is the first step in the well constraint amplitude quality control. The purpose is to use the well data to compare the shallow, medium and deep amplitude trends of the seismic data at the well point location, and constrain the vertical amplitude recovery effect of the well bypass. In the process of seismic data processing, the velocity compensation method is usually used to recover the amplitude of seismic data. However, since the recovery effect of the velocity compensation method is determined by the velocity, once the velocity is determined, the recovery effect is also determined and cannot be changed; while the exponential function compensation method controls the compensation effect through the parameter n in formula (2). Therefore, the exponential function compensation method is used to adjust the compensation effect during single well quality control.

[0069] ① Well seismic calibration

[0070] The synthetic seismic record is obtained using the longitudinal wave velocity and density of the target well. The time domain of the seismic data is converted to the depth domain of the well data using the synthetic seismic record according to the geological stratification and seismic data on the well. The depth domain stratification data on the well data is then correctly calibrated to the phase axis of the time domain in the seismic data.

[0071] ②Amplitude recovery

[0072] When embedding the amplitude quality control node in the conventional process, the velocity compensation method is used in combination with the exponential function compensation method to compensate the amplitude of the seismic data. When the curve matching does not meet the preset conditions after amplitude recovery, you can try to directly use the exponential function compensation method to compensate the amplitude of the seismic data.

[0073] ③ Comparison of amplitude energy curves

[0074] Calculate the amplitude energy curves of the synthetic seismic record and the well bypass channel, superimpose and compare the degree of fit between the two curves, and quality control whether the energy trend of the energy curve from shallow to deep is compensated in place. If the energy trend of the well bypass channel is inconsistent with the energy trend of the synthetic seismic record, adjust the parameter n in the exponential function compensation method to make the shallow, medium and deep amplitude energy trends of the well bypass channel consistent with the energy trend of the synthetic seismic record.

[0075] Step 5: Regional Amplitude Compensation

[0076] In reality, due to changes in the sedimentary environment, the underground lithology has certain lateral changes. The surface consistency amplitude compensation method used in the processing process is based on the premise that the effective wave energy is independent of the position. Therefore, when there are lateral changes in regional lithology, the amplitude of the target layer reflection wave will deviate from the lithology. In response to such a situation, the regional amplitude compensation factor method is used to extract a compensation factor in an area with small lateral lithology changes (the same sedimentary environment) to compensate for the differences caused by regional lithology differences. The compensation method is: select a relatively stable marker layer in the data, open a time window above and below the layer that can contain the marker layer, and use the amplitude energy accumulation method to obtain the energy compensation factor, and multiply the seismic data in the area by the amplitude compensation factor to achieve the purpose of compensating the amplitude of different regions. The formula for calculating the energy compensation factor is:

[0077]

[0078] Among them, E k is the kth compensation factor, i is time, j is the channel number, A is the amplitude, t is the window time, and N is the total number of channels.

[0079] Step 6: Joint well quality control

[0080] Single well quality control mainly controls the vertical energy trend of the well bypass channel based on the shallow, medium and deep amplitude energy trends of synthetic seismic records. However, since the well can only control information at one point, data far away from the well location cannot be quality controlled. In addition, if there are multiple wells, there is no way to deal with inconsistencies in the quality control results between wells. Therefore, it is necessary to quality control the amplitude recovery effect of multiple well points and between wells in a well-linked manner.

[0081] ① Division of geological strata

[0082] The calibration results of a single well can convert the geological layers in the depth domain to the seismic profile of the well location. Based on the well calibration results, the layers in the seismic data far away from the well can be interpreted and tracked. In order to improve the subsequent model effect, it is necessary to appropriately encrypt the interpretation of some auxiliary layers between the target layers.

[0083] ② Establishment and simulation of geological model

[0084] The well-linked quality control section is extracted according to the location of the quality control well, and the layer tracked on the seismic section is converted to the depth domain using the velocity and time-depth relationship of the well. A digital model is constructed based on the velocity and density curves of the well and the converted layer data, and the model is simulated to obtain the quality control model section corresponding to the well-linked section.

[0085] ③ Wave group characteristics comparison

[0086] Based on the quality control model section obtained by simulation as a ruler, the wave group characteristics and energy trends of the well-linked section and the model section of the seismic data are compared to quality control the amplitude recovery effect of the well-linked section.

[0087] ④Amplitude compensation

[0088] During the processing, the parameter n of the exponential compensation method usually uses one value for the entire study area. However, when performing quality control on multiple wells, the n parameter obtained from tests between wells is often inconsistent. If the same value is used to perform amplitude recovery on the data of the entire work area, the recovery effect of each well point position cannot be guaranteed, and it also does not conform to the actual geological situation where sedimentation changes laterally. Therefore, based on the amplitude compensation parameter value of the single well quality control, according to the distance between the shot point position and the quality control well, the n parameter is multiplied by the inverse distance weighting coefficient W to obtain the amplitude compensation parameter n value far away from the well position, so that the n value varies with the well position. The formula for obtaining the inverse distance weighting coefficient is:

[0089]

[0090] Among them, W is the weight coefficient, i is the sequence number, n i is the compensation parameter of the ith well, d i is the distance from the i-th well.

[0091] It is reasonable to use the space-variable compensation parameter value to restore the vertical amplitude of multi-well data. However, the difference in parameters will lead to lateral anomalies of the amplitude in the deep. For such lateral anomalies, it is necessary to use the regional amplitude compensation method. Formula 3 is used to calculate different regional compensation factors to compensate the target layer and eliminate lateral inconsistency.

[0092] The effect of the present invention is described below in conjunction with a specific embodiment.

[0093] Step 1: Work Area Situation Survey

[0094] The exploration area is located in the middle section of the Luliang Mountains, with a loess landform and a surface elevation of 620 to 1030 meters. The underground structure is a monocline structure with a southwest-trending trend, a gentle occurrence, and wide and gentle undulations in some areas. The strata are Paleozoic, Mesozoic and Cenozoic from old to new. The main coal-bearing strata in the area are Benxi Formation, Taiyuan Formation and Shanxi Formation. There are 11 mineable coal seams with a buried depth ranging from 1200 to 1700 meters.

[0095] Step 2: Well logging data correction

[0096] Well curves are used as a scale in the process of well control to evaluate the processing effect of seismic data, so the accuracy of well data is the premise of all quality control. Since the construction time of drilling and logging in the area is inconsistent, the logging instruments, construction teams and construction personnel are also inconsistent, so the data will be affected by factors such as instruments, well diameters, and construction speed. There will be certain differences relative to the real data. Therefore, before using the well data, the data needs to be corrected for environment, outliers and normalization to eliminate the differences caused by non-geological factors.

[0097] Step 3: Target well selection

[0098] Since the quality of logging data varies, if problematic logging or unrepresentative wells are introduced into the well control process, quality control will have a counterproductive effect. Therefore, wells that can be used for quality control need to meet the following three conditions:

[0099] ①The synthetic seismic records have a high correlation coefficient with the well bypass;

[0100] ② The well is located inside the exploration area and the seismic data has full coverage times;

[0101] ③The underground structure where the well is located is simple and the signal-to-noise ratio is good.

[0102] According to the well location plan ( Figure 2 ), well information table (Table 1) and other basic information, and wells J08 and J24 were selected as quality control target wells.

[0103] Table 1 Well information table

[0104]

[0105]

[0106] Step 4: Single Well Quality Control Results

[0107] Observe the energy curve of J24 ( Figure 3a ) It can be seen that the energy trend of the synthetic seismic record calculated based on the logging data is that the energy in the shallow part is weak, and the energy near the target layer (coal seam) is strong. This is because the shallow part is mainly sandstone and mudstone with a small reflection coefficient, and the reflection coefficient of the coal seam and the surrounding rock is large. However, in the seismic data energy curve of the well bypass, the shallow energy is similar to the deep energy. This is because there is no objective basis for judgment during the data processing process. It is usually subjective to believe that the compensation is in place when the shallow, medium and deep energy areas are consistent, so over-compensation occurs. Through the curve quality control results, the parameter n in the exponential function compensation method is reduced to adjust the amplitude. The new quality control results can be seen in Figure 3b The energy curve of the well bypass channel of the new data is basically consistent with the energy curve of the synthetic seismic record, indicating that the amplitude compensation effect is reasonable.

[0108] Step 5: Joint well quality control effect

[0109] From the cross section of J08 and J24 ( Figure 4a ) It can be seen that the overall structural form of the formation is an anticline wing. The velocity and density curves of the well and the picked-up stratigraphic data are used as the basis to build a digital model ( Figure 4b ), simulate the model to obtain the model section ( Figure 4c ). Compare the actual data profile (Figure 4a) and the model profile ( Figure 4c ) It can be seen that the structural morphology of the model is basically consistent with the actual data. Since the seismic data has been quality controlled for a single well, the vertical energy trend of the well bypass has been corrected. However, the coal seam reflection energy near well J08 in the data is weaker than that near well J24, which is inconsistent with the actual situation of the slow lateral change of the lithology of the coal-bearing strata. Figure 4d The seismic data are obtained after quality control of the parameter n and the regional amplitude compensation factor in the exponential compensation method based on the model well-linked profile. As can be seen from Figure 4d, the lateral unevenness of the coal seam reflection wave in the compensated profile has been improved.

[0110] Based on the above description, it can be seen that this embodiment uses synthetic seismic recording data from multiple wells to perform multi-point vertical amplitude trend quality control on a three-dimensional data body; this embodiment is based on the quality control results of a single well, and makes a short change to the parameter n of the exponential compensation method to make the amplitude compensation effect more in line with the actual geological conditions; this embodiment uses multiple wells to make a well-connected geological model profile, and uses this as a scale to perform quality control on data far away from the well points; therefore, the method of this embodiment can complete the vertical and lateral amplitude trend quality control of the data.

[0111] In the present embodiment, although the above methods are illustrated and described as a series of actions for simplicity of explanation, it should be understood and appreciated that these methods are not limited by the order of the actions, because according to one or more embodiments, some actions may occur in a different order and / or concurrently with other actions from those illustrated and described herein or not illustrated and described herein but understandable to those skilled in the art.

[0112] Note that references in the specification to "one embodiment," "an embodiment," "an example embodiment," "some embodiments," etc. indicate that the described embodiments may include a particular feature, structure, or characteristic, but each embodiment may not necessarily include the particular feature, structure, or characteristic. Moreover, such phrases do not necessarily refer to the same embodiment. In addition, when a particular feature, structure, or characteristic is described in conjunction with an embodiment, whether or not explicitly described, it would be within the knowledge of a person skilled in the art to implement such feature, structure, or characteristic in conjunction with other embodiments.

[0113] The previous description of the disclosure is provided to enable any person skilled in the art to make or use the disclosure. Various modifications to the disclosure will be apparent to those skilled in the art, and the general principles defined herein may be applied to other variations without departing from the spirit or scope of the disclosure. Thus, the disclosure is not intended to be limited to the examples and designs described herein, but should be granted the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A seismic amplitude quality control method based on multiple well logging data, characterized in that: include: A target well selection step is used to select a well whose logging data meets a preset condition as a target well; A spherical compensation step, for performing spherical diffusion compensation on the target well data; The single well quality control step is used to compare the shallow, medium and deep amplitude trends of the seismic data at the well point location and constrain the vertical amplitude recovery effect of the well bypass; The well-linked quality control step is used to quality control the amplitude recovery effect of multiple well points and between wells in the well-linked mode.

2. A seismic amplitude quality control method based on multiple well logging data according to claim 1, characterized in that: Also includes: The well curve correction step is used to perform environmental, outlier and normalization processing on seismic data.

3. The seismic amplitude quality control method based on multiple well logging data according to claim 1, characterized in that: In the target well selection step, the preset conditions for selecting the target well include one or more of the following conditions: (1) The correlation coefficient between the synthetic seismic record and the well bypass reaches the preset value; (2) The well is located inside the exploration area and the seismic data have full coverage.

4. The seismic amplitude quality control method based on multiple well logging data according to claim 1, characterized in that: In the spherical surface compensation step, spherical surface compensation is performed using an exponential function compensation method based on the following formula: in: A ( t ) is the amplitude after recovery, A (0) is the amplitude value before recovery, A is the amplitude value, t is the sampling time in milliseconds, and n is the exponential value that defines the compensation function.

5. The seismic amplitude quality control method based on multiple well logging data according to claim 1, characterized in that: The single well quality control step includes the following sub-steps: Well seismic calibration sub-step, using the P-wave velocity and density of the target well to obtain synthetic seismic records and perform time-depth conversion and layer calibration; Amplitude recovery sub-step, performing amplitude compensation on synthetic seismic data; The amplitude energy curve comparison sub-step calculates the amplitude energy curves of the synthetic seismic record trace and the well side trace, and quality controls whether the energy trend of the energy curve from shallow to deep is compensated in place; The regional amplitude compensation sub-step compensates for the differences caused by regional lithology differences.

6. A seismic amplitude quality control method based on multiple well logging data according to claim 5, characterized in that: In the regional amplitude compensation sub-step, the energy compensation factor of the regional lithology is obtained based on the following formula: E k For the k A compensation factor, i For time, j is the road number, A is the amplitude, t 1 is the window time, N The total number of channels.

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