Reservoir Gas Content Prediction Method, Device, Storage Medium and Electronic Device

Abstract

This application relates to the field of seismic exploration, and specifically relates to a method, device and electronic equipment for predicting gas-bearing properties of reservoirs, which solves the problem that it is difficult to obtain good gas-bearing property prediction results in the prior art. The method includes: acquiring prestack seismic data of a target reservoir; performing preprocessing on the prestack seismic data to obtain preprocessed prestack seismic data; extracting low-frequency discontinuity attributes from the preprocessed prestack seismic data to obtain low-frequency discontinuity attributes; predicting the gas-bearing property of the target reservoir according to the low-frequency discontinuity attributes and the relationship between the low-frequency discontinuity attributes and the gas-bearing property established in advance. Using prestack seismic data and low-frequency discontinuity attributes for gas-bearing property prediction can avoid the inaccuracies that exist when using high-frequency information and post-stack seismic data for gas-bearing property prediction, and can also reflect more detailed anomalies caused by oil and gas, thereby obtaining more accurate gas-bearing property prediction results for the target reservoir.

Description

Technical Field

[0001] The present application relates to the technical field of seismic exploration, and particularly to a method, device, storage medium and electronic device for predicting gas-bearing property of a reservoir. Background Art

[0002] The technology for predicting gas-bearing property of a reservoir is one of the key technologies in the field of geophysical oil and gas exploration. Good prediction results of gas-bearing property contribute to the efficient exploration and development of gas reservoirs. The prediction of gas-bearing property mainly adopts the method based on seismic attributes. Since the presence of gas in the reservoir will cause phenomena such as "high-frequency attenuation and low-frequency resonance", this phenomenon can be characterized by frequency-related seismic attributes and then used to predict the gas-bearing property of the reservoir. Therefore, the commonly used seismic attributes reflecting the gas-bearing property of the reservoir are all related to the frequency domain (time-frequency domain) attributes, and the current technology focuses on using the attributes related to high-frequency attenuation for gas-bearing property prediction. However, the high-frequency components of the data are easily affected by formation absorption attenuation and noise, and it is difficult to guarantee the quality. The obtained high-frequency-related attributes are likely to be caused by formation absorption attenuation and noise, and it is difficult to truly invert the anomalies caused by gas in the reservoir, so it is difficult to obtain good prediction results of gas-bearing property.

[0003] A brief introduction to the conventional high-frequency attribute extraction method is as follows: At the high-frequency end, due to the presence of oil and gas, the energy attenuation of the seismic signal increases, and the oil and gas detection can be carried out through the frequency attenuation gradient. On the time-frequency profile, the detected maximum energy is taken as fmax, and then the seismic wave energies f65 and f85 of 65% and 85% of fmax are calculated, and then the curve from f85 to f65 is fitted to obtain the slope of the fitted straight line, and this slope K is used as the high-frequency attenuation gradient attribute for detection; this method of obtaining the slope as an attribute by fitting a straight line uses an average thinking, that is, it does not consider the change of seismic wave energy between f65 and f85, and the same is true for other commonly used types of attributes. When there are anomalies caused by oil and gas between f65 and f85, they are often averaged out and difficult to detect.

[0004] The post-stack seismic data has a high signal-to-noise ratio, and the conventional seismic attribute analysis is based on the post-stack seismic data. However, full-angle multiple stacking is likely to lose or blur some useful information reflecting lithology or oil and gas property in the seismic data, resulting in a decrease in the sensitivity of the seismic attributes extracted from the post-stack seismic data to the reservoir characteristics, and leading to more serious multi-solution problems when using post-stack attributes to solve geological problems. Summary of the Invention

[0005] Aiming at the problem of difficult to obtain good prediction results of gas-bearing property in the prior art, the present application provides a method, device, storage medium and electronic device for predicting gas-bearing property of a reservoir.

[0006] In a first aspect, the present application provides a method for predicting gas-bearing property of a reservoir, the method comprising:

[0007] Obtain pre-stack seismic data of the target reservoir;

[0008] Preprocess the pre-stack seismic data to obtain preprocessed pre-stack seismic data;

[0009] Extract low-frequency discontinuity attributes from the preprocessed pre-stack seismic data to obtain low-frequency discontinuity attributes;

[0010] Predict the gas-bearing property of the target reservoir according to the low-frequency discontinuity attributes and the pre-established relationship between low-frequency discontinuity attributes and gas-bearing property.

[0011] In the above embodiment, the pre-stack seismic data of the target reservoir is preprocessed, and then the low-frequency discontinuity attributes are extracted from the preprocessed pre-stack seismic data to obtain low-frequency discontinuity attributes. The gas-bearing property of the target reservoir is predicted according to the low-frequency discontinuity attributes. Using pre-stack seismic data and low-frequency discontinuity attributes for gas-bearing property prediction can avoid the inaccuracies in gas-bearing property prediction when using high-frequency information and post-stack seismic data, and can also reflect more detailed anomalies caused by oil and gas, thereby obtaining more accurate prediction results of the gas-bearing property of the target reservoir.

[0012] According to an embodiment of the present application, optionally, in the above method for predicting the gas-bearing property of a reservoir, the step of preprocessing the pre-stack seismic data to obtain preprocessed pre-stack seismic data includes:

[0013] Determine the maximum angle value in the pre-stack seismic data;

[0014] Conduct characteristic analysis on the variation of amplitude with offset of the pre-stack seismic data to determine the inflection point where the amplitude changes from weak to strong;

[0015] Determine the angle range according to the maximum angle value and the inflection point;

[0016] Select target pre-stack seismic data from the pre-stack seismic data according to the angle range;

[0017] Perform partial stacking processing on the target pre-stack seismic data to obtain preprocessed pre-stack seismic data.

[0018] In the above embodiment, since there is an additional dimension of angle information in the pre-stack seismic data, it is necessary to preprocess the pre-stack seismic data to ensure accurate prediction of the gas-bearing property of the target reservoir based on the preprocessed pre-stack seismic data.

[0019] According to an embodiment of the present application, optionally, in the above method for predicting the gas-bearing property of a reservoir, the step of determining the angle range according to the maximum angle value and the inflection point includes:

[0020] Determine the angle corresponding to the inflection point as the initial angle;

[0021] Determine the range length according to the maximum angle value and the preset ratio;

[0022] Determine the angle range according to the initial angle and the range length.

[0023] In the above embodiment, there is an additional dimension of angle information in the pre-stack seismic data. The angle range can be determined according to the angle value of the pre-stack seismic data and the amplitude characteristics of the pre-stack seismic data, so as to select the target pre-stack seismic data from the pre-stack seismic data according to the angle range.

[0024] According to an embodiment of the present application, optionally, in the above reservoir gas-bearing property prediction method, the step of extracting the low-frequency discontinuity attribute from the pre-processed pre-stack seismic data to obtain the low-frequency discontinuity attribute includes:

[0025] Obtain the extraction range of the low-frequency discontinuity attribute;

[0026] Determine the product value of the slope and the frequency of each frequency point in the pre-processed pre-stack seismic data;

[0027] Determine the sum of the product values within the extraction range as the low-frequency discontinuity attribute.

[0028] According to an embodiment of the present application, optionally, in the above reservoir gas-bearing property prediction method, the step of obtaining the extraction range of the low-frequency discontinuity attribute includes:

[0029] Determine the maximum value of the spectrum of the pre-processed pre-stack seismic data;

[0030] Determine the extraction range according to the maximum value of the spectrum and the preset ratio range.

[0031] According to an embodiment of the present application, optionally, in the above reservoir gas-bearing property prediction method, the step of obtaining the extraction range of the low-frequency discontinuity attribute includes:

[0032] Obtain the sample well corresponding to the target reservoir;

[0033] Extract the low-frequency discontinuity attribute of the sample well;

[0034] Determine the extraction range according to the low-frequency discontinuity attribute of the sample well.

[0035] According to an embodiment of the present application, optionally, in the above reservoir gas-bearing property prediction method, the step of determining the extraction range according to the low-frequency discontinuity attribute of the sample well includes:

[0036] Determine the initial range according to the low-frequency discontinuous attribute of the sample well;

[0037] Obtain the difference between the gas content and water content of the sample well as the energy;

[0038] Optimize the initial range according to the energy by using the simulated annealing algorithm to obtain the extraction range.

[0039] In a second aspect, the present application also provides a device for predicting gas content in a reservoir. The device includes: a pre-stack seismic data acquisition module for acquiring pre-stack seismic data of a target reservoir;

[0040] A preprocessing module for preprocessing the pre-stack seismic data to obtain preprocessed pre-stack seismic data;

[0041] A low-frequency discontinuous attribute extraction module for extracting low-frequency discontinuous attributes from the preprocessed pre-stack seismic data to obtain low-frequency discontinuous attributes;

[0042] A gas content prediction module for predicting the gas content of the target reservoir according to the low-frequency discontinuous attribute and the relationship between the low-frequency discontinuous attribute and the gas content established in advance.

[0043] According to an embodiment of the present application, optionally, in the above device for predicting gas content in a reservoir, the preprocessing module includes:

[0044] A maximum angle value determination unit for determining the maximum angle value in the pre-stack seismic data;

[0045] An inflection point determination unit for performing feature analysis on the variation of amplitude with offset of the pre-stack seismic data to determine the inflection point where the amplitude changes from weak to strong;

[0046] An angle range determination unit for determining an angle range according to the maximum angle value and the inflection point;

[0047] A target pre-stack seismic data selection unit for selecting target pre-stack seismic data from the pre-stack seismic data according to the angle range;

[0048] A stacking processing unit for performing partial stacking processing on the target pre-stack seismic data to obtain preprocessed pre-stack seismic data.

[0049] According to an embodiment of the present application, optionally, in the above device for predicting gas content in a reservoir, the angle range determination unit includes:

[0050] An initial angle determination subunit for determining the angle corresponding to the inflection point as the initial angle;

[0051] A range length determination subunit, configured to determine a range length according to the maximum angle value and a preset ratio;

[0052] An angle range determination subunit, configured to determine an angle range according to the initial angle and the range length.

[0053] According to an embodiment of the present application, optionally, in the above reservoir gas-bearing property prediction device, the low-frequency discontinuous attribute extraction module includes:

[0054] An extraction range acquisition unit, configured to acquire an extraction range of the low-frequency discontinuous attribute;

[0055] A product value determination unit, configured to determine a product value of the slope and the frequency of each frequency point in the pre-stack seismic data after preprocessing;

[0056] A low-frequency discontinuous attribute determination unit, configured to determine that the sum of the product values within the extraction range is the low-frequency discontinuous attribute.

[0057] According to an embodiment of the present application, optionally, in the above reservoir gas-bearing property prediction device, the extraction range acquisition unit includes:

[0058] A spectrum maximum value determination subunit, configured to determine a spectrum maximum value of the pre-stack seismic data after preprocessing;

[0059] A first extraction range determination subunit, configured to determine the extraction range according to the spectrum maximum value and a preset ratio range.

[0060] According to an embodiment of the present application, optionally, in the above reservoir gas-bearing property prediction device, the extraction range acquisition unit includes:

[0061] A sample well acquisition subunit, configured to acquire a sample well corresponding to the target reservoir;

[0062] A low-frequency discontinuous attribute extraction subunit, configured to extract the low-frequency discontinuous attribute of the sample well;

[0063] A second extraction range determination subunit, configured to determine the extraction range according to the low-frequency discontinuous attribute of the sample well.

[0064] According to an embodiment of the present application, optionally, in the above reservoir gas-bearing property prediction device, the second extraction range determination subunit includes:

[0065] An initial range determination subunit, configured to determine an initial range according to the low-frequency discontinuous attribute of the sample well;

[0066] An energy acquisition unit, configured to acquire the difference between the gas-bearing property and the water-bearing property of the sample well as the energy;

[0067] An extraction range calculation subunit, configured to optimize the initial range according to the energy by using a simulated annealing algorithm to obtain the extraction range.

[0068] In a third aspect, the present application provides a storage medium. A computer program stored in the storage medium can be executed by one or more processors and can be used to implement the reservoir gas-bearing property prediction method as described above.

[0069] In a fourth aspect, the present application provides an electronic device, including a memory and a processor. A computer program is stored on the memory. When the computer program is executed by the processor, the above-mentioned reservoir gas-bearing property prediction method is executed.

[0070] Compared with the prior art, one or more embodiments in the above solution may have the following advantages or beneficial effects:

[0071] A reservoir gas-bearing property prediction method, device, storage medium and electronic device provided by the present application. The method includes: acquiring pre-stack seismic data of a target reservoir; preprocessing the pre-stack seismic data to obtain preprocessed pre-stack seismic data; extracting low-frequency discontinuity attributes from the preprocessed pre-stack seismic data to obtain low-frequency discontinuity attributes; predicting the gas-bearing property of the target reservoir according to the low-frequency discontinuity attributes and the relationship between the low-frequency discontinuity attributes and the gas-bearing property established in advance. In the above implementation manner, the pre-stack seismic data of the target reservoir is preprocessed, and then the low-frequency discontinuity attributes are extracted from the preprocessed pre-stack seismic data to obtain low-frequency discontinuity attributes. The gas-bearing property of the target reservoir is predicted according to the low-frequency discontinuity attributes. Using the pre-stack seismic data and the low-frequency discontinuity attributes for gas-bearing property prediction can avoid the inaccuracies when using high-frequency information and post-stack seismic data for gas-bearing property prediction, and can also reflect more detailed anomalies caused by oil and gas, thereby obtaining a more accurate prediction result of the gas-bearing property of the target reservoir. BRIEF DESCRIPTION OF THE DRAWINGS

[0072] Hereinafter, the present application will be described in more detail based on embodiments with reference to the drawings.

[0073] Figure 1 It is a schematic flowchart of a reservoir gas-bearing property prediction method provided in Embodiment 1 of the present application.

[0074] Figure 2 It is a schematic diagram of an analysis result of the amplitude variation characteristics with offset provided in Embodiment 2 of the present application.

[0075] Figure 3 It is a schematic diagram of an attribute extraction result provided in Embodiment 3 of the present application.

[0076] Figure 4Schematic diagram of a reservoir gas-bearing property prediction device provided in Embodiment 4 of this application.

[0077] Figure 5 Connection block diagram of an electronic device provided in Embodiment 6 of this application.

[0078] In the drawings, the same components are denoted by the same reference numerals, and the drawings are not drawn to actual scale. Detailed implementation manners

[0079] The following will describe in detail the implementation manners of this application in conjunction with the drawings and embodiments, so as to fully understand how this application uses technical means to solve technical problems and the implementation process of achieving corresponding technical effects and implement accordingly. Each feature in the embodiments of this application can be combined with each other on the premise of not conflicting, and the formed technical solutions are all within the protection scope of this application.

[0080] The post-stack seismic data has a relatively high signal-to-noise ratio, and conventional seismic attribute analysis is often based on the post-stack seismic data. However, full-angle multiple stacking is likely to lose or blur some useful information reflecting lithology or hydrocarbon properties in the seismic data, resulting in a reduced sensitivity of the seismic attributes extracted from the post-stack seismic data to reservoir characteristics, and leading to a more serious multi-solution problem when using post-stack attributes to solve geological problems. Compared with the post-stack seismic data, the pre-stack seismic data contains richer formation information and is more sensitive to the reflection of underground structures, lithology, and physical property parameters. The reservoir gas-bearing property prediction method provided in this application is proposed based on the pre-stack seismic data.

[0081] Example 1

[0082] The present invention provides a reservoir gas-bearing property prediction method. Please refer to Figure 1 , and the method includes the following steps:

[0083] Step S110: Obtain the pre-stack seismic data of the target reservoir.

[0084] The pre-stack seismic data has richer amplitude and travel time information compared with the post-stack seismic data, and some subtle formation features can be reflected in the pre-stack seismic data. Therefore, the pre-stack seismic data of the target reservoir can be obtained to ensure that more characteristic information of the target reservoir can be obtained to the greatest extent, and then ensure accurate prediction of the reservoir gas-bearing property subsequently.

[0085] Step S120: Perform preprocessing on the pre-stack seismic data to obtain the preprocessed pre-stack seismic data.

[0086] Since the post-stack seismic data is equal to the zero-offset data and the incident angle is 90 degrees, it is not necessary to preferentially select the seismic angle when extracting attenuation attributes using post-stack seismic data. When pre-stack seismic data is to be used for low-frequency discontinuity attribute extraction, because there is an additional dimension of angle information in pre-stack seismic data, pre-stack seismic data with a certain incident angle is selected as the data basis and then the attribute extraction is carried out. Therefore, it is necessary to preprocess the pre-stack seismic data to ensure the accuracy of the prediction results.

[0087] Step S130: Extract low-frequency discontinuity attributes from the preprocessed pre-stack seismic data to obtain low-frequency discontinuity attributes.

[0088] When predicting the gas-bearing property of a reservoir using pre-stack seismic data, due to the influence of underground faults or fractures on the seismic data, the amplitude loss of the high-frequency information part is serious, making the reservoir prediction results often not match the actual situation of the real reservoir. Therefore, the gas-bearing property of the target reservoir can be predicted using the low-frequency discontinuity attributes of the seismic data to ensure the accuracy of the prediction results.

[0089] Step S140: Predict the gas-bearing property of the target reservoir according to the low-frequency discontinuity attributes and the pre-established relationship between the low-frequency discontinuity attributes and the gas-bearing property.

[0090] Before predicting the gas-bearing property of the target reservoir according to the low-frequency discontinuity attributes, the low-frequency discontinuity attribute data and the gas-bearing property of other reservoirs can be analyzed and the relationship between the low-frequency discontinuity attributes and the gas-bearing property can be established. For example, a prediction model representing the relationship between the low-frequency discontinuity attributes and the gas-bearing property can be established by using the neural network method, or other methods can be used for establishment, and specific limitations are not made here.

[0091] In summary, the present application provides a method for predicting the gas-bearing property of a reservoir, including: obtaining pre-stack seismic data of a target reservoir; preprocessing the pre-stack seismic data to obtain preprocessed pre-stack seismic data; extracting low-frequency discontinuity attributes from the preprocessed pre-stack seismic data to obtain low-frequency discontinuity attributes; predicting the gas-bearing property of the target reservoir according to the low-frequency discontinuity attributes and the pre-established relationship between the low-frequency discontinuity attributes and the gas-bearing property. In the above embodiments, the pre-stack seismic data of the target reservoir is preprocessed, and then the low-frequency discontinuity attributes are extracted from the preprocessed pre-stack seismic data to obtain low-frequency discontinuity attributes. The gas-bearing property of the target reservoir is predicted according to the low-frequency discontinuity attributes. Using pre-stack seismic data and low-frequency discontinuity attributes for gas-bearing property prediction can avoid the inaccuracies when using high-frequency information and post-stack seismic data for gas-bearing property prediction, and can also reflect more detail anomalies caused by oil and gas, thereby obtaining more accurate prediction results of the gas-bearing property of the target reservoir.

[0092] Example 2

[0093] Based on the first embodiment, in this embodiment, the method in the first embodiment is illustrated through specific implementation cases.

[0094] Since there is an additional dimension of angle information in pre-stack seismic data, pre-stack data with a certain incident angle can be selected as the data basis, that is, preprocess the pre-stack seismic data.

[0095] According to an embodiment of the present application, optionally, in the above reservoir gas-bearing property prediction method, the step S120 of preprocessing the pre-stack seismic data to obtain preprocessed pre-stack seismic data includes the following steps:

[0096] Step S121: Determine the maximum angle value in the pre-stack seismic data.

[0097] The maximum angle theta_max in the pre-stack seismic data that can be obtained at the target layer depth of the target reservoir.

[0098] Step S121: Perform characteristic analysis on the variation of the amplitude of the pre-stack seismic data with the offset to determine the inflection point where the amplitude changes from weak to strong.

[0099] Generally, due to the influence of acquisition conditions, the pre-stack seismic data of the target reservoir will show the characteristics of weak-strong-weak. Therefore, by combining the characteristic analysis of the variation of the data amplitude with the offset (Amplitude variation with offset, AVO), the inflection point where the amplitude of the pre-stack seismic data changes from weak to strong can be determined. AVO technology is used to study the variation characteristics of seismic reflection amplitude with the distance between the shot point and the receiver, that is, the offset (or incident angle), to explore the variation of the reflection coefficient response with the offset (or incident angle), and then determine the lithological characteristics and physical property parameters of the overlying and underlying media of the reflection interface. With the help of AVO analysis, the rock properties of oil and gas reservoirs can be better evaluated, including property parameters such as porosity, density, lithology, and fluid content. The theoretical basis of AVO is Zoeppritz's equation. The pre-stack seismic inversion developed based on AVO theory can predict formation elastic parameters through observed seismic data and is an important seismic data quantitative interpretation technology.

[0100] Step S121: Determine the angle range according to the maximum angle value and the inflection point;

[0101] After obtaining the maximum angle value and the inflection point, the angle range can be determined according to them.

[0102] Optionally, in the above method for predicting gas-bearing property of a reservoir, step S121 of determining an angular range according to the maximum angle value and the inflection point includes the following steps:

[0103] Step S1211: Determine the angle corresponding to the inflection point as the initial angle.

[0104] Step S1212: Determine the range length according to the maximum angle value and a preset ratio.

[0105] Step S1213: Determine the angular range according to the initial angle and the range length.

[0106] For example, take the inflection point where it changes from weak to strong as the initial angle, take 1 / 3 of the maximum angle theta_max as the range length, and select the angles within the range length starting from the initial angle as the angular range. As Figure 2 shown, if theta_max = 30, then the range length is 10. Combining the amplitude change with offset AVO for feature analysis, the angle corresponding to the inflection point where the amplitude changes from weak to strong is 12, then the selected angular range of the basic data is 12 - 22.

[0107] Step S121: Select target prestack seismic data from the prestack seismic data according to the angular range.

[0108] Step S121: Perform partial stacking processing on the target prestack seismic data to obtain the preprocessed prestack seismic data.

[0109] After determining the angular range, select the prestack seismic data with angles within this angular range from the prestack seismic data as the target prestack seismic data. Then perform partial stacking processing on the target prestack seismic data to obtain the preprocessed prestack seismic data.

[0110] Example 3

[0111] Based on Embodiment 1, this embodiment illustrates the method in Embodiment 1 through a specific implementation case.

[0112] At the high-frequency end, due to the presence of oil and gas, the attenuation of the seismic signal energy increases, and oil and gas detection can be carried out through the frequency attenuation gradient. On the time-frequency profile, take the detected maximum energy as fmax, then calculate the seismic wave energies f65 and f85 of 65% and 85% of fmax, then fit the curve from f85 to f65, obtain the slope of the fitted straight line, and use this slope K as the high-frequency attenuation gradient attribute for detection, as Figure 3 shown.

[0113] This fitting utilizes an average thinking method, that is, it does not consider the seismic wave energy change between f65 and f85, and the same is true for other common types of attributes. Correspondingly, there is a corresponding low-frequency attenuation attribute in the low-frequency band.

[0114] Therefore, when extracting the low-frequency discontinuity attribute, the f65 and f85 in the low-frequency band can be used as the starting and ending positions for fitting, obtaining the corresponding fitting line, and determining the low-frequency discontinuity attribute according to this fitting line.

[0115] As another implementation manner, the present application also provides a method for extracting the low-frequency discontinuity attribute that can reflect each frequency point. Among them, each frequency point can be discontinuous. According to the embodiments of the present application, optionally, in the above-mentioned reservoir gas-bearing property prediction method, the step S130 of extracting the low-frequency discontinuity attribute from the preprocessed prestack seismic data to obtain the low-frequency discontinuity attribute includes the following steps:

[0116] Step S131: Obtain the extraction range of the low-frequency discontinuity attribute.

[0117] The extraction range of the low-frequency discontinuity attribute can be pre-stored in the database or pre-set, or can be determined according to relevant data. The specific method for obtaining is not elaborated here.

[0118] Step S132: Determine the product value of the slope and frequency of each frequency point in the preprocessed prestack seismic data.

[0119] Due to the characteristics of the spectrum itself, the high-frequency slope is relatively low, while the low-frequency slope is relatively high. In order to balance the attribute and truly reflect the anomaly, the slope of each frequency point can be multiplied by the frequency point.

[0120] Step S133: Determine that the sum of the product values within the extraction range is the low-frequency discontinuity attribute.

[0121] Then, by summing the product values within the extraction range, the low-frequency discontinuity attribute can be obtained.

[0122] Among them, when obtaining the extraction range of the low-frequency discontinuity attribute, in addition to the direct acquisition method, it can also be obtained through the following several methods.

[0123] In the first implementation manner, when obtaining the extraction range of the low-frequency discontinuity attribute, the spectrum maximum value of the preprocessed prestack seismic data can be determined first, and then the extraction range can be determined according to the spectrum maximum value and the preset proportional range.

[0124] In the second implementation, when obtaining the extraction range of the low-frequency discontinuity attribute, the sample wells corresponding to the target reservoir can be obtained first, and then the low-frequency discontinuity attributes of the sample wells are extracted. Finally, the extraction range is determined according to the low-frequency discontinuity attributes of the sample wells.

[0125] Among them, the step of determining the extraction range according to the low-frequency discontinuity attributes of the sample wells includes the following process. First, an initial range is determined according to the low-frequency discontinuity attributes of the sample wells, and then the difference between the gas-bearing property and the water-bearing property of the sample wells is obtained as the energy. Finally, the initial range is optimized by using the simulated annealing algorithm according to the energy to obtain the extraction range.

[0126] Typical gas-producing wells with high yields and wells in water-bearing or tight reservoirs in the study area are selected as sample wells, and the low-frequency discontinuity attributes of the sample wells are extracted respectively. The frequency range of the extracted low-frequency discontinuity attributes is used as the extraction range (i.e., f top and f bot ). This extraction range can be optimized as a variable that can be changed. The difference between the gas-bearing property and the water-bearing property is used as the energy of the simulated annealing algorithm, and the extraction range is used as the parameter to be optimized. The final frequency range (i.e., f top and f bot ) can be obtained.

[0127] It can be understood that when extracting the low-frequency discontinuity attribute from the preprocessed prestack seismic data to obtain the low-frequency discontinuity attribute, if the extraction range of the low-frequency discontinuity attribute has been obtained, the extraction range of the initial low-frequency discontinuity attribute can be optimized according to the implementation manner of obtaining the extraction range of the low-frequency discontinuity attribute above, so as to ensure accurate extraction of the low-frequency discontinuity attribute.

[0128] For example, when obtaining the extraction range of the low-frequency discontinuity attribute, if the pre-stored extraction range is directly obtained from the database, or the extraction range used in the previous extraction of the low-frequency discontinuity attribute is used, then afterwards, the extraction range of the low-frequency discontinuity attribute can be obtained by using the above method, and then the obtained extraction range is optimized, so as to ensure that the low-frequency discontinuity attribute can be obtained more accurately according to the optimized extraction range.

[0129] As a specific implementation, when extracting the low-frequency discontinuity attribute, the low-frequency discontinuity attribute can be extracted according to the following formula:

[0130]

[0131] Among them, K d represents that the attribute is the low-frequency discontinuity attribute, f top represents the maximum value in the extraction range, f botThe minimum value of the extraction range represents the slope at each frequency point, where f represents the frequency at each frequency point, and each frequency point can be discontinuous.

[0132] where f top and f bot can be determined using a preset proportional range of the maximum amplitude. For example, 85% and 65% of the maximum amplitude are used as f top and f bot . The extraction range can also be determined using the low-frequency discontinuity property of the sample well.

[0133] Due to the inherent characteristics of the spectrum, the high-frequency slope is relatively low and the low-frequency slope is relatively high. To balance the properties and truly reflect the anomalies, the product of the slope and frequency at each frequency point can be used as the property value at each point. Add up all the property values within the range from f bot to f top to obtain K d low-frequency discontinuity property.

[0134] Example 4

[0135] Please refer to Figure 4 , this application provides a reservoir gas-bearing property prediction device 400, which includes:[[]]

[0136] A pre-stack seismic data acquisition module 410 for acquiring pre-stack seismic data of a target reservoir;

[0137] A preprocessing module 420 for preprocessing the pre-stack seismic data to obtain preprocessed pre-stack seismic data;

[0138] A low-frequency discontinuity property extraction module 430 for extracting low-frequency discontinuity properties from the preprocessed pre-stack seismic data to obtain low-frequency discontinuity properties;

[0139] A gas-bearing property prediction module 440 for predicting the gas-bearing property of the target reservoir according to the low-frequency discontinuity property and the relationship between the low-frequency discontinuity property and the gas-bearing property established in advance.

[0140] According to an embodiment of this application, optionally, in the above reservoir gas-bearing property prediction device, the preprocessing module 420 includes:[[]]

[0141] A maximum angle value determination unit for determining the maximum angle value in the pre-stack seismic data;

[0142] An inflection point determination unit for performing feature analysis on the change of amplitude with offset in the pre-stack seismic data to determine the inflection point where the amplitude changes from weak to strong;

[0143] An angle range determination unit for determining an angle range according to the maximum angle value and the inflection point;

[0144] A target pre-stack seismic data selection unit for selecting target pre-stack seismic data from the pre-stack seismic data according to the angle range;

[0145] A stacking processing unit for performing partial stacking processing on the target pre-stack seismic data to obtain pre-processed pre-stack seismic data.

[0146] According to an embodiment of the present application, optionally, in the above reservoir gas-bearing property prediction device, the angle range determination unit includes:

[0147] An initial angle determination subunit for determining the angle corresponding to the inflection point as the initial angle;

[0148] A range length determination subunit for determining a range length according to the maximum angle value and a preset ratio;

[0149] An angle range determination subunit for determining an angle range according to the initial angle and the range length.

[0150] According to an embodiment of the present application, optionally, in the above reservoir gas-bearing property prediction device, the low-frequency discontinuity attribute extraction module 430 includes:

[0151] An extraction range acquisition unit for acquiring an extraction range of the low-frequency discontinuity attribute;

[0152] A product value determination unit for determining a product value of the slope and the frequency of each frequency point in the pre-processed pre-stack seismic data;

[0153] A low-frequency discontinuity attribute determination unit for determining the sum of the product values within the extraction range as the low-frequency discontinuity attribute.

[0154] According to an embodiment of the present application, optionally, in the above reservoir gas-bearing property prediction device, the extraction range acquisition unit includes:

[0155] A spectrum maximum value determination subunit for determining the spectrum maximum value of the pre-processed pre-stack seismic data;

[0156] A first extraction range determination subunit for determining the extraction range according to the spectrum maximum value and a preset ratio range.

[0157] According to an embodiment of the present application, optionally, in the above reservoir gas-bearing property prediction device, the extraction range acquisition unit includes:

[0158] A sample well acquisition subunit for acquiring a sample well corresponding to the target reservoir;

[0159] A low-frequency discontinuity attribute extraction subunit, configured to extract the low-frequency discontinuity attribute of the sample well;

[0160] A second extraction range determination subunit, configured to determine the extraction range according to the low-frequency discontinuity attribute of the sample well.

[0161] According to an embodiment of the present application, optionally, in the above reservoir gas-bearing property prediction device, the second extraction range determination subunit includes:

[0162] An initial range determination subunit, configured to determine an initial range according to the low-frequency discontinuity attribute of the sample well;

[0163] An energy acquisition subunit, configured to acquire the difference between the gas-bearing property and the water-bearing property of the sample well as energy;

[0164] An extraction range calculation subunit, configured to optimize the initial range according to the energy by using a simulated annealing algorithm to obtain the extraction range.

[0165] In summary, the present application provides a reservoir gas-bearing property prediction device, including: a pre-stack seismic data acquisition module 410, configured to acquire pre-stack seismic data of a target reservoir; a preprocessing module 420, configured to preprocess the pre-stack seismic data to obtain preprocessed pre-stack seismic data; a low-frequency discontinuity attribute extraction module 430, configured to extract low-frequency discontinuity attributes from the preprocessed pre-stack seismic data to obtain low-frequency discontinuity attributes; a gas-bearing property prediction module 440, configured to predict the gas-bearing property of the target reservoir according to the low-frequency discontinuity attributes and the relationship between the low-frequency discontinuity attributes and the gas-bearing property established in advance. In the above implementation manner, the pre-stack seismic data of the target reservoir is preprocessed, and then the low-frequency discontinuity attributes are extracted from the preprocessed pre-stack seismic data to obtain low-frequency discontinuity attributes. The gas-bearing property of the target reservoir is predicted according to the low-frequency discontinuity attributes. Using pre-stack seismic data and low-frequency discontinuity attributes for gas-bearing property prediction can avoid the inaccuracies in gas-bearing property prediction when using high-frequency information and post-stack seismic data, and can also reflect more detailed anomalies caused by oil and gas, thereby obtaining a more accurate prediction result of the gas-bearing property of the target reservoir.

[0166] Example 5

[0167] This embodiment also provides a computer-readable storage medium, such as a flash memory, a hard disk, a multimedia card, a card-type memory (e.g., SD or DX memory, etc.), a random access memory (RAM), a static random access memory (SRAM), a read-only memory (ROM), an electrically erasable programmable read-only memory (EEPROM), a programmable read-only memory (PROM), a magnetic memory, a magnetic disk, an optical disk, a server, an App application store, etc., on which a computer program is stored. When the computer program is executed by a processor, the following method steps can be implemented:

[0168] Step S110: Obtain the pre-stack seismic data of the target reservoir;

[0169] Step S120: Preprocess the pre-stack seismic data to obtain the preprocessed pre-stack seismic data;

[0170] Step S130: Extract the low-frequency discontinuity attribute from the preprocessed pre-stack seismic data to obtain the low-frequency discontinuity attribute;

[0171] Step S140: Predict the gas-bearing property of the target reservoir according to the low-frequency discontinuity attribute and the relationship between the low-frequency discontinuity attribute and the gas-bearing property established in advance.

[0172] In the above implementation manner, the pre-stack seismic data of the target reservoir is preprocessed, and then the low-frequency discontinuity attribute is extracted from the preprocessed pre-stack seismic data to obtain the low-frequency discontinuity attribute. The gas-bearing property of the target reservoir is predicted according to the low-frequency discontinuity attribute. Using the pre-stack seismic data and the low-frequency discontinuity attribute for gas-bearing property prediction can avoid the inaccuracies when using high-frequency information and post-stack seismic data for gas-bearing property prediction, and can also reflect more detailed anomalies caused by oil and gas, thereby obtaining more accurate prediction results of the gas-bearing property of the target reservoir.

[0173] Optionally, in the above method for predicting the gas-bearing property of a reservoir, the step of preprocessing the pre-stack seismic data to obtain the preprocessed pre-stack seismic data includes:

[0174] Determine the maximum angle value in the pre-stack seismic data;

[0175] Conduct a characteristic analysis of the change of amplitude with offset of the pre-stack seismic data to determine the inflection point where the amplitude changes from weak to strong;

[0176] Determine the angle range according to the maximum angle value and the inflection point;

[0177] Select the target pre-stack seismic data from the pre-stack seismic data according to the angle range;

[0178] Perform partial stacking processing on the target prestack seismic data to obtain the prestack seismic data after preprocessing.

[0179] In the above embodiment, since there is an additional dimension of angle information in the prestack seismic data, it is necessary to preprocess the prestack seismic data to ensure accurate prediction of the gas-bearing property of the target reservoir based on the prestack seismic data after preprocessing.

[0180] Optionally, in the above reservoir gas-bearing property prediction method, the step of determining the angle range according to the maximum angle value and the inflection point includes:

[0181] Determine the angle corresponding to the inflection point as the initial angle;

[0182] Determine the range length according to the maximum angle value and a preset ratio;

[0183] Determine the angle range according to the initial angle and the range length.

[0184] In the above embodiment, there is an additional dimension of angle information in the prestack seismic data. The angle range can be determined according to the angle value of the prestack seismic data and the amplitude characteristics of the prestack seismic data, so as to select the target prestack seismic data from the prestack seismic data according to the angle range.

[0185] Optionally, in the above reservoir gas-bearing property prediction method, the step of extracting the low-frequency discontinuity attribute from the prestack seismic data after preprocessing to obtain the low-frequency discontinuity attribute includes:

[0186] Obtain the extraction range of the low-frequency discontinuity attribute;

[0187] Determine the product value of the slope and the frequency of each frequency point in the prestack seismic data after preprocessing;

[0188] Determine the sum of the product values within the extraction range as the low-frequency discontinuity attribute.

[0189] Optionally, in the above reservoir gas-bearing property prediction method, the step of obtaining the extraction range of the low-frequency discontinuity attribute includes:

[0190] Determine the maximum value of the spectrum of the prestack seismic data after preprocessing;

[0191] Determine the extraction range according to the maximum value of the spectrum and a preset ratio range.

[0192] Optionally, in the above reservoir gas-bearing property prediction method, the step of obtaining the extraction range of the low-frequency discontinuity attribute includes:

[0193] Obtain the sample well corresponding to the target reservoir;

[0194] Extract the low-frequency discontinuous attributes of the sample well;

[0195] Determine the extraction range according to the low-frequency discontinuous attributes of the sample well.

[0196] Optionally, in the above reservoir gas-bearing property prediction method, the step of determining the extraction range according to the low-frequency discontinuous attributes of the sample well includes:

[0197] Determine the initial range according to the low-frequency discontinuous attributes of the sample well;

[0198] Obtain the difference between the gas-bearing property and the water-bearing property of the sample well as the energy;

[0199] Optimize the initial range according to the energy by using the simulated annealing algorithm to obtain the extraction range.

[0200] For the specific implementation process of the above method steps, refer to Embodiment 1, and this embodiment will not be repeated here.

[0201] Example 6

[0202] An embodiment of the present application provides an electronic device, which may be a mobile phone, a computer, a tablet computer, etc., including a memory and a processor. A calculator program is stored on the memory, and when the computer program is executed by the processor, it implements the reservoir gas-bearing property prediction method described in Embodiment 1. It can be understood that as Figure 5 shown, the electronic device 500 may further include: a processor 501, a memory 502, a multimedia component 503, an input / output (I / O) interface 504, and a communication component 505.

[0203] Among them, the processor 501 is used to execute all or part of the steps in the reservoir gas-bearing property prediction method in Embodiment 1. The memory 502 is used to store various types of data, which may include, for example, instructions of any application program or method in the electronic device, and data related to the application program.

[0204] The processor 501 can be implemented by an Application Specific Integrated Circuit (ASIC), a Digital Signal Processor (DSP), a Digital Signal Processing Device (DSPD), a Programmable Logic Device (PLD), a Field Programmable Gate Array (FPGA), a controller, a microcontroller, a microprocessor, or other electronic components, and is used to execute the reservoir gas-bearing property prediction method in the first embodiment above.

[0205] The memory 502 can be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as a Static Random Access Memory (SRAM), an Electrically Erasable Programmable Read-Only Memory (EEPROM), an Erasable Programmable Read-Only Memory (EPROM), a Programmable Read-Only Memory (PROM), a Read-Only Memory (ROM), a magnetic memory, a flash memory, a magnetic disk, or an optical disc.

[0206] The multimedia component 503 can include a screen and an audio component. The screen can be a touch screen, and the audio component is used to output and / or input audio signals. For example, the audio component can include a microphone for receiving external audio signals. The received audio signals can be further stored in the memory or sent through the communication component. The audio component also includes at least one speaker for outputting audio signals.

[0207] The I / O interface 504 provides an interface between the processor 501 and other interface modules, and the other interface modules can be a keyboard, a mouse, buttons, etc. These buttons can be virtual buttons or physical buttons.

[0208] The communication component 505 is used for the electronic device 500 to communicate with other devices in a wired or wireless manner. Wireless communication, such as Wi-Fi, Bluetooth, Near Field Communication (NFC), 2G, 3G or 4G, or a combination of one or more of them. Accordingly, the communication component 505 may include: a Wi-Fi module, a Bluetooth module, and an NFC module.

[0209] In summary, a method, device, storage medium and electronic device for predicting gas-bearing property of a reservoir provided by the present application. The method includes: obtaining pre-stack seismic data of a target reservoir; preprocessing the pre-stack seismic data to obtain preprocessed pre-stack seismic data; extracting low-frequency discontinuity attributes from the preprocessed pre-stack seismic data to obtain low-frequency discontinuity attributes; and predicting the gas-bearing property of the target reservoir according to the low-frequency discontinuity attributes and the pre-established relationship between the low-frequency discontinuity attributes and the gas-bearing property. In the above embodiments, the pre-stack seismic data of the target reservoir is preprocessed, and then the low-frequency discontinuity attributes are extracted from the preprocessed pre-stack seismic data to obtain the low-frequency discontinuity attributes. The gas-bearing property of the target reservoir is predicted according to the low-frequency discontinuity attributes.

[0210] Using the pre-stack seismic data and the low-frequency discontinuity attributes for gas-bearing property prediction can avoid the inaccuracies when using high-frequency information and post-stack seismic data for gas-bearing property prediction, and can also reflect more detailed anomalies caused by oil and gas, thereby obtaining a more accurate prediction result of the gas-bearing property of the target reservoir.

[0211] In several embodiments provided by the embodiments of the present application, it should be understood that the disclosed systems and methods can also be implemented in other ways. The system and method embodiments described above are merely illustrative.

[0212] It should be noted that in this article, the term "including", "comprising" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements, but also includes other elements not expressly listed, or also includes elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "including a..." does not exclude the existence of another identical element in the process, method, article or device including the element.

[0213] Although the embodiments disclosed in this application are as above, the content described is only an embodiment adopted for the convenience of understanding this application and is not used to limit this application. Any person skilled in the art within the technical field to which this application pertains may make any modifications and changes in the form of implementation and details without departing from the spirit and scope disclosed in this application. However, the scope of patent protection of this application shall still be subject to the scope defined by the appended claims.

Claims

1. A method for predicting gas-bearing property of a reservoir, characterized in that, The method includes: Obtaining pre-stack seismic data of a target reservoir; Preprocessing the pre-stack seismic data to obtain preprocessed pre-stack seismic data; Extracting low-frequency discontinuity attributes from the preprocessed pre-stack seismic data to obtain low-frequency discontinuity attributes; Predicting the gas-bearing property of the target reservoir according to the low-frequency discontinuity attributes and the pre-established relationship between low-frequency discontinuity attributes and gas-bearing property; The step of extracting low-frequency discontinuity attributes from the preprocessed pre-stack seismic data to obtain low-frequency discontinuity attributes includes: Obtaining the extraction range of low-frequency discontinuity attributes; Determining the product value of the slope and frequency of each frequency point in the preprocessed pre-stack seismic data; Determining the sum of the product values within the extraction range as the low-frequency discontinuity attribute.

2. The method according to claim 1, wherein The step of preprocessing the pre-stack seismic data to obtain preprocessed pre-stack seismic data includes: Determining the maximum angle value in the pre-stack seismic data; Performing characteristic analysis on the variation of amplitude with offset of the pre-stack seismic data to determine the inflection point where the amplitude changes from weak to strong; Determining the angle range according to the maximum angle value and the inflection point; Selecting target pre-stack seismic data from the pre-stack seismic data according to the angle range; Performing partial stacking processing on the target pre-stack seismic data to obtain preprocessed pre-stack seismic data.

3. The method according to claim 2, wherein The step of determining the angle range according to the maximum angle value and the inflection point includes: Determining the angle corresponding to the inflection point as the initial angle; Determining the range length according to the maximum angle value and a preset ratio; Determining the angle range according to the initial angle and the range length.

4. The method according to claim 1, characterized in that, The step of obtaining the extraction range of low-frequency discontinuity attributes includes: Determining the maximum value of the frequency spectrum of the preprocessed pre-stack seismic data; Determining the extraction range according to the maximum value of the frequency spectrum and a preset ratio range.

5. The method according to claim 1, characterized in that, The step of obtaining the extraction range of low-frequency discontinuity attributes includes: Obtaining a sample well corresponding to the target reservoir; Extracting the low-frequency discontinuity attributes of the sample well; Determining the extraction range according to the low-frequency discontinuity attributes of the sample well.

6. The method according to claim 5, wherein The step of determining the extraction range according to the low-frequency discontinuity attributes of the sample well includes: Determining the initial range according to the low-frequency discontinuity attributes of the sample well; Obtaining the difference between the gas-bearing property and water-bearing property of the sample well as the energy; Optimizing the initial range according to the energy by using a simulated annealing algorithm to obtain the extraction range.

7. A reservoir gas-bearing property prediction device, characterized in that, The device includes: A pre-stack seismic data acquisition module for obtaining pre-stack seismic data of a target reservoir; A preprocessing module for preprocessing the pre-stack seismic data to obtain preprocessed pre-stack seismic data; A low-frequency discontinuity attribute extraction module for extracting low-frequency discontinuity attributes from the preprocessed pre-stack seismic data to obtain low-frequency discontinuity attributes; A gas-bearing property prediction module for predicting the gas-bearing property of the target reservoir according to the low-frequency discontinuity attributes and the pre-established relationship between low-frequency discontinuity attributes and gas-bearing property; The low-frequency discontinuity attribute extraction module includes: An extraction range acquisition unit for acquiring an extraction range of low-frequency discontinuous attributes; A product value determination unit for determining a product value of the slope and the frequency of each frequency point in the preprocessed prestack seismic data; A low-frequency discontinuous attribute determination unit for determining that the sum of the product values within the extraction range is a low-frequency discontinuous attribute.

8. A storage medium, characterized in that, The computer program stored in the storage medium, when executed by one or more processors, is used to implement the method described in any one of claims 1-6.

9. An electronic device, characterized in that, It includes a memory and a processor. A computer program is stored on the memory. When the computer program is executed by the processor, the method described in any one of claims 1-6 is executed.

Images