Poisson impedance gas content prediction method for eliminating physical property influence and electronic device

Abstract

The application discloses a Poisson impedance gas-bearing property prediction method and electronic equipment, and relates to the field of geophysical prospecting.The method comprises the following steps: establishing a rock physics model;replacing physical properties of the rock physics model;obtaining the Poisson impedance after the single-well physical property replacement;obtaining the fitting relationship between the Poisson impedance after the physical property replacement and the original Poisson impedance and the original porosity;obtaining the Poisson impedance after the physical property replacement of the target area based on the fitting relationship, the original Poisson impedance and the original porosity of the target area;and predicting the gas-bearing property of the target area according to the Poisson impedance after the physical property replacement of the target area.The application establishes the fitting relationship between the Poisson impedance after the physical property replacement and the original Poisson impedance and the original porosity based on the rock physics model, obtains the Poisson impedance after the physical property replacement of the target area, eliminates the influence of the physical property parameters on the Poisson impedance, and detects the gas-bearing property of the target area by using the Poisson impedance without the influence of the physical properties, so that the prediction result is accurate.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of oil exploration, and particularly relates to a Poisson impedance gas-bearing property prediction method for eliminating the influence of physical properties and an electronic device. BACKGROUND

[0002] Poisson impedance is a combination of Poisson ratio and density, which is actually the difference between P-wave impedance and S-wave impedance. The intersection of P-wave impedance and S-wave impedance can effectively show the difference in gas saturation of sandstone. Therefore, the Poisson impedance attribute has good application effect in the prediction of some specific gas-bearing reservoirs.

[0003] For areas where the reservoir physical properties change slightly, the gas-bearing property prediction by Poisson impedance is relatively accurate, but for areas where the reservoir physical properties change obviously, the gas-bearing property prediction by Poisson impedance is not accurate enough. Therefore, the gas-bearing property prediction by Poisson impedance has obvious limitations, which further affects the further promotion of the method. The fundamental reason affecting the further promotion and application is that the influence of reservoir physical properties on Poisson impedance is not eliminated in the process of obtaining Poisson impedance, so that the Poisson impedance attribute contains the information of reservoir physical properties, which further affects the accuracy of gas-bearing property prediction.

[0004] Therefore, it is necessary to develop a Poisson impedance gas-bearing property prediction method capable of eliminating the influence of physical properties. SUMMARY

[0005] The application aims to provide a Poisson impedance gas-bearing property prediction method capable of eliminating the influence of physical properties.

[0006] In a first aspect, the application provides a Poisson impedance gas-bearing property prediction method capable of eliminating the influence of physical properties, which comprises: establishing a rock physical model based on logging curves; replacing the physical properties of the rock physical model; obtaining the Poisson impedance after physical property replacement of a single well based on the rock physical model after physical property replacement; obtaining the fitting relationship between the Poisson impedance after physical property replacement and the original Poisson impedance and the original porosity based on the Poisson impedance after physical property replacement of a single well, the original Poisson impedance and the original porosity of a single well; obtaining the Poisson impedance after physical property replacement of a target area based on the fitting relationship, the original Poisson impedance and the original porosity of the target area; and performing gas-bearing property prediction of the target area according to the Poisson impedance after physical property replacement of the target area.

[0007] Optionally, the establishing of the rock physical model based on the logging curves comprises: obtaining the sandy content, argillaceous content, porosity and gas saturation in the logging curves; and establishing the rock physical model based on the sandy content, argillaceous content, porosity and gas saturation.

[0008] Optionally, the petrophysical model replacement includes: modifying the porosity of the petrophysical model; supplementing shale in the petrophysical model after the porosity is modified, and calculating the shale content after the replacement.

[0009] Optionally, the shale content after the replacement is calculated by the following formula:

[0010] Vclay_new=Vpor-Vpor_common+Vclay

[0011] Wherein, Vclay_new is the shale content after the replacement, Vpor is the porosity before the replacement, Vpor_common is the modified porosity, and Vclay is the shale content before the replacement.

[0012] Optionally, based on the petrophysical model after the petrophysical replacement, the single-well petrophysical replacement Poisson impedance is obtained by: calculating the P-wave velocity and the S-wave velocity of the petrophysical model after the petrophysical replacement under the sand content, the modified porosity, and the shale content after the replacement; and calculating the single-well petrophysical replacement Poisson impedance based on the P-wave velocity and the S-wave velocity.

[0013] Optionally, the single-well petrophysical replacement Poisson impedance is calculated by the following formula:

[0014] PI=AI–c*SI

[0015] Wherein, PI is Poisson impedance, AI is P-wave impedance, c is a coefficient, and SI is S-wave impedance.

[0016] Optionally, the gas-bearing property prediction of the target area according to the petrophysical replacement Poisson impedance of the target area includes: drawing a Poisson impedance prediction map based on the petrophysical replacement Poisson impedance of the target area.

[0017] The gas-bearing property of the target area is predicted based on the Poisson impedance prediction map.

[0018] Optionally, the single-well original P-wave velocity, the single-well original S-wave velocity, and the single-well original porosity are obtained based on the logging curve; and the single-well original Poisson impedance is obtained based on the single-well original P-wave velocity and the single-well original S-wave velocity.

[0019] Optionally, the three-parameter inversion is performed on the pre-stack seismic data of the target area to obtain the original P-wave velocity and the original S-wave velocity of the target area, the original Poisson impedance of the target area is obtained based on the original P-wave velocity and the original S-wave velocity of the target area; and the Bayesian petrophysical parameter inversion is performed on the pre-stack seismic data of the target area to obtain the original porosity of the target area.

[0020] In a second aspect, the present application also provides an electronic device, comprising: a memory, which stores executable instructions; and a processor, which executes the executable instructions in the memory to implement the method for predicting gas-bearing property by eliminating influence of physical property on Poisson impedance.

[0021] The method for predicting gas-bearing property by eliminating influence of physical property on Poisson impedance has the advantages that: the method is based on rock physics modeling, a fitting relationship between the Poisson impedance after physical property replacement and the original Poisson impedance and the original porosity is established by the method of physical property replacement, the Poisson impedance after physical property replacement of the target area is obtained according to the fitting relationship, the original Poisson impedance and the original porosity of the target area, the influence of the physical property parameter on the Poisson impedance is eliminated, the target area is detected for gas-bearing property by the Poisson impedance after eliminating the influence of the physical property, and the prediction result is accurate.

[0022] The present application has other characteristics and advantages that will be apparent from or that will be elaborated upon in the accompanying drawings and subsequent detailed description incorporated herein, which together serve to explain certain principles of the present application. BRIEF DESCRIPTION OF DRAWINGS

[0023] The above and other objects, features and advantages of the present application will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings in which like reference characters refer to like parts throughout the several views, and wherein exemplary embodiments of the present application are shown.

[0024] Figure 1 A flow chart of a method for predicting gas-bearing property by eliminating influence of physical property on Poisson impedance according to an embodiment of the present application is shown.

[0025] Figure 2 A basic flow chart of a method for predicting gas-bearing property by eliminating influence of physical property on Poisson impedance according to an embodiment of the present application is shown.

[0026] Figure 3 A P-wave impedance and S-wave impedance crossplot before physical property replacement is shown.

[0027] Figure 4 A P-wave impedance and S-wave impedance crossplot after physical property replacement of a method for predicting gas-bearing property by eliminating influence of physical property on Poisson impedance according to an embodiment of the present application is shown.

[0028] Figure 5 A gas-bearing property prediction graph of the Poisson impedance after physical property replacement of a method for predicting gas-bearing property by eliminating influence of physical property on Poisson impedance according to an embodiment of the present application is shown. DETAILED DESCRIPTION

[0029] Preferred embodiments of the present application will be described in greater detail below. While the preferred embodiments of the present application are described below, it is to be understood that the present application can be carried out in various forms and should not be limited to the embodiments set forth herein.

[0030] The present application provides a Poisson impedance gas-bearing property prediction method for eliminating the influence of physical properties, comprising: establishing a rock physics model based on logging curves; performing physical property replacement on the rock physics model; obtaining single-well physical property-replaced Poisson impedance based on the physical property-replaced rock physics model; obtaining a fitting relationship between the physical property-replaced Poisson impedance and the original Poisson impedance and the original porosity based on the single-well physical property-replaced Poisson impedance, the single-well original Poisson impedance and the single-well original porosity; obtaining the physical property-replaced Poisson impedance of a target region based on the fitting relationship, the original Poisson impedance and the original porosity of the target region; and performing gas-bearing property prediction of the target region according to the physical property-replaced Poisson impedance of the target region.

[0031] Specifically, the P-wave impedance AI and the S-wave impedance are calculated through the P-wave velocity, the S-wave velocity and the density of the logging curves, and the P-wave impedance and the S-wave impedance are cross-plotted to analyze the sensitivity of the P-wave impedance and the S-wave impedance to the gas saturation, and it is considered that the difference in physical properties is the reason for the analysis of the logging curves and the geological conditions.

[0032] The physical property replacement is performed on the rock physics model, the single-well physical property-replaced Poisson impedance is obtained based on the physical property-replaced rock physics model, the fitting relationship between the physical property-replaced Poisson impedance and the original Poisson impedance and the original porosity is established through the multivariate fitting of the single-well physical property-replaced Poisson impedance, the single-well original Poisson impedance and the single-well original porosity, the physical property-replaced Poisson impedance of the target region is calculated according to the fitting relationship and the original Poisson impedance and the original porosity of the target region, and the gas-bearing property prediction is performed according to the physical property-replaced Poisson impedance.

[0033] According to the exemplary embodiments, the Poisson impedance gas-bearing property prediction method for eliminating the influence of physical properties is based on rock physics modeling, the fitting relationship between the physical property-replaced Poisson impedance and the original Poisson impedance and the original porosity is established through the method of physical property replacement, the physical property-replaced Poisson impedance of the target region is obtained according to the fitting relationship, the original Poisson impedance and the original porosity of the target region, the influence of the physical property parameters on the Poisson impedance is eliminated, the gas-bearing property detection of the target region is performed through the Poisson impedance for eliminating the influence of physical properties, and the prediction result is accurate.

[0034] As an optional solution, the establishment of the rock physics model based on the logging curves comprises: obtaining the sandy content, the argillaceous content, the porosity and the gas saturation in the logging curves; and establishing the rock physics model based on the sandy content, the argillaceous content, the porosity and the gas saturation.

[0035] Specifically, according to the P-wave velocity, S-wave velocity, density, porosity, mineral content, and gas saturation data in the well logging curve, it is assumed that the rock mainly consists of sand content Vsand, clay content Vclay, and porosity Vpor, and a rock physics model is established according to the sand content Vsand, clay content Vclay, porosity Vpor, and gas saturation.

[0036] As an optional solution, the physical property replacement of the rock physics model includes: modifying the porosity of the rock physics model; supplementing clay in the rock physics model after the porosity is modified, and calculating the replaced clay content.

[0037] As an optional solution, the replaced clay content is calculated by the following formula:

[0038] Vclay_new = Vpor - Vpor_common + Vclay

[0039] Wherein, Vclay_new is the replaced clay content, Vpor is the porosity before replacement, Vpor_common is the modified porosity, and Vclay is the clay content before replacement.

[0040] Specifically, the physical property replacement is performed based on the rock physics model, and all porosity values are replaced by a constant value Vpor_common. At this time, it is assumed that the sand content in the rock does not change, and the increased or decreased porosity is supplemented by the clay content, that is,

[0041] Vclay_new = Vpor - Vpor_common + Vclay.

[0042] The P-wave velocity Vp_new, S-wave velocity Vs_new, and density Den_new of the rock physics model at the sand content Vsand, the replaced clay content Vclay_new, and the porosity Vpor_common, as well as the P-wave impedance AI_new and S-wave impedance SI_new are calculated.

[0043] As an optional solution, based on the rock physics model after the physical property replacement, the single-well physical property replacement Poisson impedance is obtained, including: calculating the P-wave velocity and S-wave velocity of the rock physics model after the physical property replacement at the sand content, the modified porosity, and the replaced clay content; and based on the P-wave velocity and S-wave velocity, calculating the single-well physical property replacement Poisson impedance.

[0044] As an optional solution, the single-well physical property replacement Poisson impedance is calculated by the following formula:

[0045] PI = AI - c * SI

[0046] Wherein, PI is Poisson impedance, AI is longitudinal wave impedance, c is a coefficient, and SI is transverse wave impedance.

[0047] Specifically, the Poisson impedance after the single-well physical property replacement is calculated according to a Poisson impedance formula.

[0048] As an optional solution, the gas-bearing property prediction of the target region according to the Poisson impedance after the physical property replacement of the target region comprises: drawing a Poisson impedance prediction map based on the Poisson impedance after the physical property replacement of the target region; and predicting the gas-bearing property of the target region based on the Poisson impedance prediction map.

[0049] Specifically, the gas-bearing position of the target region is determined according to the graph in the drawn Poisson impedance prediction map.

[0050] As an optional solution, the original single-well longitudinal wave velocity, the original single-well transverse wave velocity and the original single-well porosity are obtained based on the logging curve; and the original single-well Poisson impedance is obtained based on the original single-well longitudinal wave velocity and the original single-well transverse wave velocity.

[0051] Specifically, the original single-well Poisson impedance is obtained by substituting the original single-well longitudinal wave velocity and the original single-well transverse wave velocity into the Poisson impedance formula.

[0052] As an optional solution, the original longitudinal wave velocity and the original transverse wave velocity of the target region are obtained by performing three-parameter inversion on the pre-stack seismic data of the target region; the original Poisson impedance of the target region is obtained based on the original longitudinal wave velocity and the original transverse wave velocity of the target region; and the original porosity of the target region is obtained by performing Bayesian physical property parameter inversion on the pre-stack seismic data of the target region.

[0053] Specifically, the original longitudinal wave velocity, the original transverse wave velocity and the density body of the target region are obtained by performing pre-stack three-parameter inversion on the pre-stack seismic data of the target region; the original Poisson impedance of the target region is obtained by substituting the original longitudinal wave velocity and the original transverse wave velocity into the formula PI=AI–c*SI.

[0054] The original porosity body of the target region is obtained by performing Bayesian physical property parameter inversion on the pre-stack seismic data of the target region; the original Poisson impedance and the original porosity body of the target region are substituted into the fitting relationship according to the fitting relationship; and the Poisson impedance after the physical property replacement of the target region, i.e., the Poisson impedance eliminating the influence of physical properties, is calculated.

[0055] The application further provides an electronic device, which comprises a memory storing executable instructions and a processor running the executable instructions in the memory to realize the above-mentioned Poisson impedance gas-bearing property prediction method eliminating the influence of physical properties.

[0056] Embodiment one

[0057] Figure 1A flow chart of a method for eliminating the influence of physical properties on Poisson impedance gas prediction is shown according to an embodiment of the present application. Figure 2 A basic flow chart of a method for eliminating the influence of physical properties on Poisson impedance gas prediction is shown according to an embodiment of the present application. Figure 3 A P-wave impedance and S-wave impedance crossplot before physical property replacement is shown. Figure 4 A P-wave impedance and S-wave impedance crossplot after physical property replacement of a method for eliminating the influence of physical properties on Poisson impedance gas prediction is shown according to an embodiment of the present application. Figure 5 A Poisson impedance gas prediction plot after physical property replacement of a method for eliminating the influence of physical properties on Poisson impedance gas prediction is shown according to an embodiment of the present application.

[0058] In combination with Figure 1 , Figure 2 , Figure 3 , Figure 4 and Figure 5 , the method for eliminating the influence of physical properties on Poisson impedance gas prediction comprises:

[0059] Step 1: establishing a rock physics model based on logging curves;

[0060] In which, establishing a rock physics model based on logging curves comprises: obtaining sand content, shale content, porosity and gas saturation in the logging curves; and establishing a rock physics model based on the sand content, shale content, porosity and gas saturation.

[0061] Step 2: performing physical property replacement on the rock physics model;

[0062] In which, performing physical property replacement on the rock physics model comprises: modifying the porosity of the rock physics model; and supplementing shale in the rock physics model after modifying the porosity, and calculating the replaced shale content.

[0063] In which, the replaced shale content is calculated by the following formula:

[0064] Vclay_new = Vpor - Vpor_common + Vclay

[0065] In which, Vclay_new is the replaced shale content, Vpor is the porosity before replacement, Vpor_common is the modified porosity, and Vclay is the shale content before replacement.

[0066] Step 3: obtaining the single-well physical property-replaced Poisson impedance based on the rock physics model after physical property replacement;

[0067] Among them, based on the rock physics model after physical property replacement, obtaining the Poisson impedance after physical property replacement of a single well includes: calculating the P-wave velocity and S-wave velocity of the rock physics model after physical property replacement under sand content, modified porosity, and replaced mud content; and calculating the Poisson impedance after physical property replacement of a single well based on the P-wave velocity and S-wave velocity.

[0068] Among them, the Poisson impedance after single well physical property replacement is calculated by the following formula;

[0069] PI=AI–c*SI

[0070] Where PI is the Poisson impedance, AI is the longitudinal wave impedance, c is the coefficient, and SI is the shear wave impedance.

[0071] Step 4: Based on the Poisson impedance after physical property replacement, the original Poisson impedance of the single well, and the original porosity of the single well, obtain the fitting relationship between the Poisson impedance after physical property replacement and the original Poisson impedance and original porosity;

[0072] Among them, the original P-wave velocity, original S-wave velocity and original porosity of a single well are obtained based on the well logging curve; the original Poisson impedance of a single well is obtained based on the original P-wave velocity and original S-wave velocity of a single well.

[0073] Step 5: Based on the fitting relationship, the original Poisson impedance and the original porosity of the target area, the Poisson impedance of the target area after physical property replacement is obtained;

[0074] Among them, three-parameter inversion is performed on the pre-stack seismic data of the target area to obtain the original P-wave velocity and original S-wave velocity of the target area. Based on the original P-wave velocity and original S-wave velocity of the target area, the original Poisson impedance of the target area is obtained; Bayesian physical property parameter inversion is performed on the pre-stack seismic data of the target area to obtain the original porosity of the target area.

[0075] Step 6: Predict the gas content of the target area based on the Poisson impedance after replacing the physical properties of the target area.

[0076] The method of predicting the gas content of the target area according to the Poisson impedance after the physical property replacement of the target area includes: drawing a Poisson impedance prediction map based on the Poisson impedance after the physical property replacement of the target area; and predicting the gas content of the target area based on the Poisson impedance prediction map.

[0077] like Figure 3 As shown, Figure 3 It is difficult to distinguish the difference in gas saturation of sandstones by using the P-wave impedance and S-wave impedance of a single well (SW is water saturation). Figure 4 This is the cross-plot of P-wave impedance and S-wave impedance after single well physical property replacement. The P-wave impedance and S-wave impedance in the figure can effectively represent the difference in gas saturation of sandstone (SW is water saturation).Figure 5 As shown, the gas-bearing property prediction is performed by replacing the Poisson impedance of the target area with the physical property, and the prediction result is highly consistent with the drilling production data.

[0078] Embodiment Two

[0079] The electronic device includes a memory storing executable instructions, and a processor running the executable instructions in the memory to implement the above-mentioned Poisson impedance gas-bearing property prediction method eliminating the influence of physical properties.

[0080] The electronic device according to the embodiments of the present disclosure includes a memory and a processor.

[0081] The memory is configured to store non-transitory computer-readable instructions. Specifically, the memory can include one or more computer program products, which can include various forms of computer-readable storage media, such as volatile memory and / or non-volatile memory. The volatile memory may, for example, include random access memory (RAM), cache memory, and / or the like. The non-volatile memory may, for example, include read-only memory (ROM), hard disk, flash memory, and / or the like.

[0082] The processor can be a central processing unit (CPU) or other form of processing unit having data processing and / or instruction execution capabilities, and can control other components in the electronic device to perform desired functions. In one embodiment of the present disclosure, the processor is configured to run the computer-readable instructions stored in the memory.

[0083] Those skilled in the art will understand that, in order to solve the technical problem of how to obtain a good user experience effect, the present embodiment can also include well-known structures such as a communication bus, an interface, and the like, which should also be included in the protection scope of the present disclosure.

[0084] Detailed descriptions of the present embodiment can be referred to the corresponding descriptions in the foregoing embodiments, which will not be repeated here.

[0085] The embodiments of the present disclosure have been described above, and the above descriptions are exemplary, not exhaustive, and are not limited to the disclosed embodiments. Many modifications and changes will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments.

Claims

1. A Poisson impedance gas content prediction method that eliminates the influence of physical properties, characterized in that: include: Establish rock physics model based on well logging curves; Performing physical property replacement on the rock physics model; Based on the rock physics model after physical property replacement, the Poisson impedance of a single well after physical property replacement is obtained; Based on the Poisson impedance after physical property replacement, the original Poisson impedance of the single well, and the original porosity of the single well, a fitting relationship between the Poisson impedance after physical property replacement and the original Poisson impedance and original porosity is obtained; Based on the fitting relationship, the original Poisson impedance and the original porosity of the target area, obtaining the Poisson impedance of the target area after physical property replacement; Predicting the gas content of the target area based on the Poisson impedance after the physical properties of the target area are replaced; The performing of physical property replacement on the rock physics model includes: modifying the porosity of the rock physics model; Adding mud to the rock physics model after porosity modification and calculating the content of the replaced mud; The mud content after replacement is calculated by the following formula: Vclay_new=Vpor-Vpor_common+Vclay; Among them, Vclay_new is the clay content after replacement, Vpor is the porosity before replacement, Vpor_common is the modified porosity, and Vclay is the clay content before replacement.

2. The Poisson impedance gas content prediction method for eliminating the influence of physical properties according to claim 1, characterized in that: The rock physics model is established based on the well logging curves, including: Obtaining sand content, mud content, porosity and gas saturation from the well logging curve; A rock physics model is established based on the sand content, mud content, porosity and gas saturation.

3. The Poisson impedance gas content prediction method for eliminating the influence of physical properties according to claim 2, characterized in that: The method of obtaining the Poisson impedance of a single well after physical property replacement based on the rock physics model after physical property replacement includes: Calculating the P-wave velocity and S-wave velocity of the rock physics model after the physical property replacement under the conditions of the sand content, the modified porosity, and the replaced shale content; Based on the longitudinal wave velocity and the shear wave velocity, the Poisson impedance after the physical property replacement of the single well is calculated.

4. The Poisson impedance gas content prediction method for eliminating the influence of physical properties according to claim 3, characterized in that: The Poisson impedance after the physical property replacement of the single well is calculated by the following formula; PI =AI –c*SI Where PI is the Poisson impedance, AI is the longitudinal wave impedance, c is the coefficient, and SI is the shear wave impedance.

5. The Poisson impedance gas content prediction method for eliminating the influence of physical properties according to claim 1, characterized in that: The gas content prediction of the target area according to the Poisson impedance after the physical property replacement of the target area includes: Drawing a Poisson impedance prediction graph based on the Poisson impedance after the physical property replacement of the target area; The gas content of the target area is predicted based on the Poisson impedance prediction map.

6. The Poisson impedance gas content prediction method for eliminating the influence of physical properties according to claim 5, characterized in that: The original P-wave velocity, the original S-wave velocity and the original porosity of the single well are obtained based on the well logging curve; the original Poisson impedance of the single well is obtained based on the original P-wave velocity and the original S-wave velocity of the single well.

7. The Poisson impedance gas content prediction method for eliminating the influence of physical properties according to claim 1, characterized in that: Performing three-parameter inversion on pre-stack seismic data of a target area to obtain original P-wave velocity and original S-wave velocity of the target area, and obtaining original Poisson impedance of the target area based on the original P-wave velocity and original S-wave velocity of the target area; The original porosity of the target area is obtained by performing Bayesian physical property inversion on the pre-stack seismic data of the target area.

8. An electronic device, characterized in that: The electronic device comprises: a memory storing executable instructions; A processor runs the executable instructions in the memory to implement the Poisson impedance gas content prediction method for eliminating physical property effects according to any one of claims 1 to 7.

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