Density curve correction method and device based on density rock physical model

Abstract

The invention discloses a density curve correction method and device based on a density rock physical model, and the method comprises the steps: obtaining the density rock physical model under the condition that the density curve is distorted; determining the density corresponding to each rock component in the density curve according to a non-expanding section curve in the density curve; determining a new density curve according to the density rock physical model and the density corresponding to each rock component; and determining a corrected density curve according to the new density curve. The density rock physical model can be used for representing the corresponding relation between the density in the density curve and the volume components of the multiple rock components and the density of the multiple rock components, the density curve is corrected according to the corresponding relation, the rationality of the correction process can be improved, and the accuracy of the corrected density curve can be improved.

Description

Technical Field

[0001] The present invention relates to the field of seismic data processing in the field of earth science, and more specifically, to a correction method and device for a density curve based on a density rock physics model. Background Art

[0002] As oil and gas exploration continues to deepen, the exploration depth continues to increase, reservoir properties deteriorate, and reservoir prediction and fluid detection become increasingly difficult. Geophysical logging and seismic exploration, as key technologies in oil and gas exploration, play an increasingly important role, and density data has great value in both logging and seismic exploration. As a key curve in logging, the density curve plays an important role in logging interpretation, especially porosity interpretation. However, the distortion of the density curve will restrict subsequent logging interpretation, oil and gas exploration, etc., so developers urgently need a correction method for the density curve. Summary of the invention

[0003] In view of this, the present invention discloses a method for correcting a density curve based on a density rock physics model when there is an error in the density curve.

[0004] According to one aspect of the present invention, a correction method for a density curve based on a density rock physics model is proposed, the correction method comprising: obtaining a density rock physics model in the case of a distorted density curve; wherein the density rock physics model is used to represent the correspondence between the density in the density curve and the volume components of a plurality of rock components and the density of the plurality of rock components; determining the density corresponding to each rock component in the density curve according to a non-expanded section curve in the density curve; determining a new density curve according to the density rock physics model and the density corresponding to each rock component; and determining a corrected density curve according to the new density curve.

[0005] In some embodiments, the density rock physics model may be expressed as: Among them, ρ is used to represent the density in the density curve, N is used to represent the total number of multiple rock components, and f i It is used to represent the volume component of the i-th rock component, ρ i Used to represent the density of the i-th rock component.

[0006] In some embodiments, the rock components include: mineral components, pore fluid components, and the density corresponding to each rock component in the density curve is determined according to the non-expansion section curve in the density curve, including: determining the non-reservoir section mineral comprehensive density corresponding to the non-reservoir section mineral component according to the mineral density corresponding to the non-reservoir section mineral component in the non-expansion section curve; adjusting the reservoir section mineral density with a porosity less than a preset value according to the non-reservoir section mineral comprehensive density, until the difference between the target density obtained by substituting the non-reservoir section mineral comprehensive density and the reservoir section mineral density with a porosity less than a preset value into the density rock physics model and the corresponding density in the density curve is less than the preset difference, and the reservoir section mineral density corresponding to the target density is used as the target reservoir section mineral density; determining the reservoir section pore fluid component density and the non-reservoir section pore fluid component density according to the preset oil and gas saturation curve.

[0007] In some embodiments, the new density curve is determined based on the density rock physics model and the density corresponding to each rock component, including: substituting the mineral density of the non-reservoir section, the pore fluid component density of the non-reservoir section, the mineral density of the target reservoir section, and the pore fluid component density of the reservoir section into the density rock physics model to obtain a new density curve.

[0008] In some embodiments, determining a corrected density curve based on the new density curve includes at least one of the following: obtaining a first density distribution of a non-expanded section corresponding to the density curve and a second density distribution of the new density curve in the non-expanded section, and when the difference between the first density distribution and the second density distribution is less than the first difference, using the new density curve as the corrected density curve; obtaining a third density distribution of an expanded section corresponding to the density curve and a fourth density distribution of the new density curve in the expanded section, and when the density in the third density distribution is less than the density at the same depth in the fourth density distribution and the total number of densities is greater than a preset total number, using the new density curve as the corrected density curve; comparing the density in the new density curve with the actual density of the core at the same depth, and when the density change trend of the new density curve is consistent with the change trend of the actual density of the core, using the new density curve as the corrected density curve.

[0009] According to one aspect of the present invention, a correction device for a density curve based on a density rock physics model is also proposed, the correction device comprising: a model acquisition module, used to acquire the density rock physics model when the density curve is distorted; wherein the density rock physics model is used to represent the correspondence between the density in the density curve and the volume components of multiple rock components and the density of multiple rock components; a density determination module, used to determine the density corresponding to each rock component in the density curve according to the non-expanded section curve in the density curve; a curve determination module, used to determine a new density curve according to the density rock physics model and the density corresponding to each rock component; and a correction module, used to determine the corrected density curve according to the new density curve.

[0010] In some embodiments, the density rock physics model may be expressed as: Among them, ρ is used to represent the density in the density curve, N is used to represent the total number of multiple rock components, and f i It is used to represent the volume component of the i-th rock component, ρ i Used to represent the density of the i-th rock component.

[0011] In some embodiments, the rock components include: mineral components and pore fluid components. The density determination module is also used to determine the non-reservoir section mineral comprehensive density corresponding to the non-reservoir section mineral component based on the mineral density corresponding to the non-reservoir section mineral component in the non-expansion section curve; adjust the reservoir section mineral density with a porosity less than a preset value based on the non-reservoir section mineral comprehensive density, until the difference between the target density obtained by substituting the non-reservoir section mineral comprehensive density and the reservoir section mineral density with a porosity less than a preset value into the density rock physics model and the corresponding density in the density curve is less than the preset difference, and the reservoir section mineral density corresponding to the target density is used as the target reservoir section mineral density; determine the reservoir section pore fluid component density and the non-reservoir section pore fluid component density based on the preset oil and gas saturation curve.

[0012] In some embodiments, the curve determination module is also used to substitute the mineral density of the non-reservoir section, the pore fluid component density of the non-reservoir section, the mineral density of the target reservoir section, and the pore fluid component density of the reservoir section into the density rock physics model to obtain a new density curve.

[0013] In some embodiments, the correction module is also used to perform at least one of the following: obtaining a first density distribution of a non-expanded section corresponding to the density curve and a second density distribution of the new density curve in the non-expanded section, and when the difference between the first density distribution and the second density distribution is less than the first difference, using the new density curve as a corrected density curve; obtaining a third density distribution of an expanded section corresponding to the density curve and a fourth density distribution of the new density curve in the expanded section, and when the density in the third density distribution is less than the density at the same depth in the fourth density distribution and the total number of densities is greater than a preset total number, using the new density curve as a corrected density curve; comparing the density in the new density curve with the actual density measured in the core at the same depth, and when the density change trend of the new density curve is consistent with the change trend of the actual density measured in the core, using the new density curve as a corrected density curve.

[0014] According to another aspect of the present invention, an electronic device is also proposed, comprising: a memory storing executable instructions; a processor running the executable instructions in the memory to implement the density curve correction method based on the density rock physics model described above.

[0015] According to another aspect of the present invention, a computer-readable storage medium is provided, which stores a computer program. When the computer program is executed by a processor, the method for correcting a density curve based on a density rock physics model described above is implemented.

[0016] This technical solution has at least the following advantages: the embodiment of the present invention can obtain a density rock physics model when the density curve is distorted, and then determine the density corresponding to each rock component in the density curve according to the non-expanded section curve in the density curve, and then determine a new density curve according to the density rock physics model and the density corresponding to each rock component, and finally determine a corrected density curve according to the new density curve. The density rock physics model in the embodiment of the present invention can be used to represent the corresponding relationship between the density in the density curve and the volume components of multiple rock components and the density of multiple rock components. Correcting the density curve accordingly can improve the rationality of the correction process and the accuracy of the corrected density curve.

[0017] The methods and apparatus of the present invention have other features and advantages that will be apparent from or will be described in detail in the accompanying drawings and subsequent detailed descriptions incorporated herein, which together serve to explain the specific principles of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The above and other objects, features and advantages of the present invention will become more apparent through a more detailed description of exemplary embodiments of the present invention in conjunction with the accompanying drawings, wherein like reference numerals generally represent like components throughout the exemplary embodiments of the present invention.

[0019] Figure 1 A flow chart of a method for correcting a density curve based on a density rock physics model according to an embodiment of the present invention is shown.

[0020] Figure 2 A reference schematic diagram of a method for correcting a density curve based on a density rock physics model according to an embodiment of the present invention is shown.

[0021] Figure 3 A reference schematic diagram of a method for correcting a density curve based on a density rock physics model according to an embodiment of the present invention is shown.

[0022] Figure 4 A reference schematic diagram of a method for correcting a density curve based on a density rock physics model according to an embodiment of the present invention is shown. DETAILED DESCRIPTION

[0023] In the related art, in the actual density curve measurement, due to the influence of well conditions, the density curve has obvious distortion when the diameter is expanded. In view of the density curve distortion phenomenon, there are different methods to perform density correction. For example, in the prior art, since the velocity curve is less affected by the well conditions, the density curve can be calculated by the velocity-density empirical formula in the diameter expansion section. However, the conventional density curve correction method in the prior art is corrected by an approximate relationship, so the accuracy of the correction is difficult to guarantee.

[0024] In view of this, the embodiment of the present invention can obtain a density rock physics model when the density curve is distorted, and then determine the density corresponding to each rock component in the density curve according to the non-expanded section curve in the density curve, and then determine a new density curve according to the density rock physics model and the density corresponding to each rock component, and finally determine a corrected density curve according to the new density curve. The density rock physics model in the embodiment of the present invention can be used to represent the corresponding relationship between the density in the density curve and the volume components of multiple rock components and the density of multiple rock components. Correcting the density curve accordingly can improve the rationality of the correction process and the accuracy of the corrected density curve.

[0025] The preferred embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although the preferred embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided to make the present invention more thorough and complete, and to fully convey the scope of the present invention to those skilled in the art.

[0026] Example 1

[0027] Figure 1 The flowchart of the method for correcting a density curve based on a density rock physics model according to an embodiment of the present invention is shown. As shown in the figure, the method includes steps 1 to 4.

[0028] Step 1, in the case of distorted density curve, obtain the density rock physics model. The density rock physics model is used to represent the correspondence between the density in the density curve and the volume components of multiple rock components and the density of multiple rock components. Exemplarily, the above-mentioned density curve can be obtained by the developer through the data acquisition equipment in the relevant technology, and the embodiment of the present invention will not be elaborated here, and it can be used to represent the relationship between density and depth. The specific composition of the density rock physics model can be adjusted by the developer according to the actual situation, and it can represent the correspondence between the density in the density curve and the volume components of multiple rock components and the density of multiple rock components. In an example, the density rock physics model can be expressed as: Among them, ρ is used to represent the density in the density curve, N is used to represent the total number of multiple rock components, and f i It is used to represent the volume component of the i-th rock component, ρ i It is used to represent the density of the i-th rock component. It should be understood that those skilled in the art may also weight different rock components or adjust corresponding parameters according to actual conditions, and the embodiment of the present invention does not limit this. The distortion of the above density curve may be determined automatically or manually in combination with the detection experience of the developer and the preset rules, and the embodiment of the present invention does not limit this.

[0029] Step 2: Determine the density corresponding to each rock component in the density curve according to the non-expanded diameter curve in the density curve. For example, the density curve may include an expanded diameter curve and a non-expanded diameter curve. The expanded diameter curve may be used to represent an inaccurate part of the density curve, and the non-expanded diameter curve may be used to represent a relatively accurate part of the density curve. Figure 2 , Figure 2A reference schematic diagram of a density curve correction method based on a density rock physics model according to an embodiment of the present invention is shown. In this figure, five sub-graphs are included, namely, a relationship diagram between wellbore diameter and depth (where CAL1 to CAL3 are different wellbore curves for the same well), a relationship diagram between porosity and depth, a relationship diagram between mineral composition (where VQU is quartz and VCLY is mud) and depth, a relationship diagram between calcite content and depth, and a relationship diagram between original density and depth (that is, the density curve described herein). The acquisition methods of the above five sub-graphs can all be acquired and calculated using acquisition equipment in the relevant technology, and the embodiments of the present invention will not be elaborated herein. Figure 2 The three rectangles in the figure represent three diameter expansion curves, which means that the depths corresponding to the three rectangles are distorted. The embodiment of the present invention calculates the density corresponding to each rock component in the density curve through the non-diameter expansion curve with higher accuracy, which can improve the accuracy of determining the density corresponding to each rock component, and is conducive to improving the accuracy of the corrected density curve finally generated.

[0030] In a possible implementation, the rock components may include: mineral components, pore fluid components, and step 2 may include: according to the mineral density corresponding to the non-reservoir segment mineral components in the non-expansion segment curve, determining the non-reservoir segment mineral comprehensive density corresponding to the non-reservoir segment mineral components. For example, here, the rock is sandstone as an example, the main mineral composition of its non-reservoir segment is argillaceous minerals, and the porosity is also close to 0 (that is, there is basically no pore fluid component), so it can be approximately considered that the non-reservoir segment is composed of pure argillaceous minerals, and the measured density of the non-reservoir segment can be approximated as the density of argillaceous minerals. When the non-argillaceous minerals (for example, quartz) in the non-reservoir segment account for a certain proportion, it is also necessary to consider the influence of non-argillaceous minerals on the measured modulus and density. In other words, the non-reservoir segment mineral comprehensive density is related to the mineral density corresponding to each non-reservoir segment mineral component. In an example, a weighted average value can be obtained according to its specific content. The embodiment of the present invention is not limited here. The mineral density corresponding to each non-reservoir segment mineral component of the non-reservoir segment mineral comprehensive density is generally positively correlated. Then, according to the comprehensive mineral density of the non-reservoir section, the mineral density of the reservoir section with a porosity less than the preset value is adjusted until the difference between the target density obtained by substituting the comprehensive mineral density of the non-reservoir section and the mineral density of the reservoir section with a porosity less than the preset value into the density rock physics model and the corresponding density in the density curve is less than the preset difference, and the mineral density of the reservoir section corresponding to the target density is used as the target reservoir section mineral density. The above preset value can be approximately 0. The lower the porosity, that is, the lower the pore fluid component, the more representative the mineral density corresponding to the layer section with a porosity less than the preset value is. The specific value can be determined by the developer according to the actual situation, and the embodiment of the present invention does not limit it here. Continuing from the above example, for sandstone and mudstone, the reservoir section mainly includes: sandy minerals (for example: quartz or feldspar), mud minerals, and pore fluid components. The density of mud minerals (in this example, that is, the comprehensive mineral density of the non-reservoir section mentioned above) has been determined, and what needs to be determined is the density of sandy minerals and the density of pore fluid components. Therefore, the embodiment of the present invention selects a layer section with a porosity less than a preset value. The pore fluid component in this layer section can be regarded as 0, so only the density of sandy minerals needs to be determined. Substituting the comprehensive density of minerals in the non-reservoir section and the mineral density corresponding to the layer section with a porosity adjusted to be less than the preset value into the density rock physics model mentioned above, the target density can be obtained. Then, according to the preset oil and gas saturation curve, the density of the pore fluid component in the reservoir section and the density of the pore fluid component in the non-reservoir section are determined. Exemplarily, the above-mentioned oil and gas saturation curve can be collected and obtained by relevant equipment, and the density of the pore fluid (oil, gas, water) can be determined by the curve. The specific calculation method is not described in detail in the embodiment of the present invention.

[0031] Step 3, determine a new density curve according to the density rock physics model and the density corresponding to each rock component. Exemplarily, after obtaining the density corresponding to each of the above rock components, the new density curve can be directly calculated. In one example, this step may include: substituting the mineral density of the non-reservoir section, the density of the pore fluid component of the non-reservoir section, the mineral density of the target reservoir section, and the density of the pore fluid component of the reservoir section into the density rock physics model to obtain a new density curve.

[0032] Step 4: Determine a corrected density curve according to the new density curve. For example, the new density curve can be directly used as the corrected density curve. In another example, the new density curve can also be subjected to distortion evaluation and used as the corrected density curve after meeting the requirements.

[0033] In a possible implementation, step 4 may include obtaining a first density distribution of the non-expanded diameter section corresponding to the density curve, a second density distribution of the new density curve in the non-expanded diameter section, and when the difference between the first density distribution and the second density distribution is less than the first difference, the new density curve is used as the corrected density curve. Exemplarily, if the density distributions of the two in the non-expanded diameter section are similar, the density prediction of the new density curve is more reasonable, and it can be used as the corrected density curve. Step 4 may also include obtaining a third density distribution of the expanded diameter section corresponding to the density curve, a fourth density distribution of the new density curve in the expanded diameter section, and when the total number of densities in the third density distribution is less than the density at the same depth in the fourth density distribution and is greater than a preset total number, the new density curve is used as the corrected density curve. The density curve usually exhibits abnormally low density characteristics in the expanded diameter section. If the predicted density of the new density curve in the expanded diameter section is greater than the original density, the density prediction of the new density curve is more reasonable, and it can be used as the corrected density curve. Step 4 may also include comparing the density in the new density curve with the measured density of the core at the same depth. When the density change trend of the new density curve is consistent with the change trend of the measured density of the core, the new density curve is used as the corrected density curve. In combination with actual conditions, developers can also obtain cores of key layers and conduct rock physics experiments on them, such as density measurement. The measured density of the core can be compared with the density in the new density curve. If the density change trends are similar, the density prediction of the new density curve is more reasonable and can be used as the corrected density curve. It should be understood that the above three methods can also be combined. When all three are met, the new density curve is used as the corrected density curve. The embodiment of the present invention does not limit this. After verifying the rationality of the new density curve by multiple methods, the density in the new density curve can be used to replace the measured density in the expansion section, thereby obtaining high-precision density data, ensuring the accuracy of subsequent logging interpretation, seismic interpretation, etc.

[0034] Example 2

[0035] According to an embodiment of the present invention, a correction device for a density curve based on a density rock physics model is provided. The correction device comprises: a model acquisition module, which is used to acquire a density rock physics model when the density curve is distorted; wherein the density rock physics model is used to represent the correspondence between the density in the density curve and the volume components of multiple rock components and the density of multiple rock components; a density determination module, which is used to determine the density corresponding to each rock component in the density curve according to the non-expanded section curve in the density curve; a curve determination module, which is used to determine a new density curve according to the density rock physics model and the density corresponding to each rock component; and a correction module, which is used to determine a corrected density curve according to the new density curve.

[0036] In some embodiments, the density rock physics model may be expressed as: Among them, ρ is used to represent the density in the density curve, N is used to represent the total number of multiple rock components, and f i It is used to represent the volume component of the i-th rock component, ρ i Used to represent the density of the i-th rock component.

[0037] In some embodiments, the rock components include: mineral components and pore fluid components. The density determination module is also used to determine the non-reservoir section mineral comprehensive density corresponding to the non-reservoir section mineral component based on the mineral density corresponding to the non-reservoir section mineral component in the non-expansion section curve; adjust the reservoir section mineral density with a porosity less than a preset value based on the non-reservoir section mineral comprehensive density, until the difference between the target density obtained by substituting the non-reservoir section mineral comprehensive density and the reservoir section mineral density with a porosity less than a preset value into the density rock physics model and the corresponding density in the density curve is less than the preset difference, and the reservoir section mineral density corresponding to the target density is used as the target reservoir section mineral density; determine the reservoir section pore fluid component density and the non-reservoir section pore fluid component density based on the preset oil and gas saturation curve.

[0038] In some embodiments, the curve determination module is also used to substitute the mineral density of the non-reservoir section, the pore fluid component density of the non-reservoir section, the mineral density of the target reservoir section, and the pore fluid component density of the reservoir section into the density rock physics model to obtain a new density curve.

[0039] In some embodiments, the correction module is also used to perform at least one of the following: obtaining a first density distribution of a non-expanded section corresponding to the density curve and a second density distribution of the new density curve in the non-expanded section, and when the difference between the first density distribution and the second density distribution is less than the first difference, using the new density curve as a corrected density curve; obtaining a third density distribution of an expanded section corresponding to the density curve and a fourth density distribution of the new density curve in the expanded section, and when the density in the third density distribution is less than the density at the same depth in the fourth density distribution and the total number of densities is greater than a preset total number, using the new density curve as a corrected density curve; comparing the density in the new density curve with the actual density measured in the core at the same depth, and when the density change trend of the new density curve is consistent with the change trend of the actual density measured in the core, using the new density curve as a corrected density curve.

[0040] Example 3

[0041] According to another aspect of the present invention, an electronic device is provided. The electronic device comprises:

[0042] Memory, which stores executable instructions:

[0043] A processor runs the executable instructions in the memory to implement the density curve correction method based on the density rock physics model according to the present invention.

[0044] The correction method comprises: obtaining a density rock physics model when a density curve is distorted; wherein the density rock physics model is used to represent the corresponding relationship between the density in the density curve and the volume components of multiple rock components and the density of multiple rock components; determining the density corresponding to each rock component in the density curve according to the non-expanded section curve in the density curve; determining a new density curve according to the density rock physics model and the density corresponding to each rock component; and determining a corrected density curve according to the new density curve.

[0045] In some embodiments, the density rock physics model may be expressed as: Among them, ρ is used to represent the density in the density curve, N is used to represent the total number of multiple rock components, and f i It is used to represent the volume component of the i-th rock component, ρ i Used to represent the density of the i-th rock component.

[0046] In some embodiments, the rock components include: mineral components, pore fluid components, and the density corresponding to each rock component in the density curve is determined according to the non-expansion section curve in the density curve, including: determining the non-reservoir section mineral comprehensive density corresponding to the non-reservoir section mineral component according to the mineral density corresponding to the non-reservoir section mineral component in the non-expansion section curve; adjusting the reservoir section mineral density with a porosity less than a preset value according to the non-reservoir section mineral comprehensive density, until the difference between the target density obtained by substituting the non-reservoir section mineral comprehensive density and the reservoir section mineral density with a porosity less than a preset value into the density rock physics model and the corresponding density in the density curve is less than the preset difference, and the reservoir section mineral density corresponding to the target density is used as the target reservoir section mineral density; determining the reservoir section pore fluid component density and the non-reservoir section pore fluid component density according to the preset oil and gas saturation curve.

[0047] In some embodiments, the new density curve is determined based on the density rock physics model and the density corresponding to each rock component, including: substituting the mineral density of the non-reservoir section, the pore fluid component density of the non-reservoir section, the mineral density of the target reservoir section, and the pore fluid component density of the reservoir section into the density rock physics model to obtain a new density curve.

[0048] In some embodiments, determining a corrected density curve based on the new density curve includes at least one of the following: obtaining a first density distribution of a non-expanded section corresponding to the density curve and a second density distribution of the new density curve in the non-expanded section, and when the difference between the first density distribution and the second density distribution is less than the first difference, using the new density curve as the corrected density curve; obtaining a third density distribution of an expanded section corresponding to the density curve and a fourth density distribution of the new density curve in the expanded section, and when the density in the third density distribution is less than the density at the same depth in the fourth density distribution and the total number of densities is greater than a preset total number, using the new density curve as the corrected density curve; comparing the density in the new density curve with the actual density of the core at the same depth, and when the density change trend of the new density curve is consistent with the change trend of the actual density of the core, using the new density curve as the corrected density curve.

[0049] Example 4

[0050] According to another aspect of the present invention, a computer-readable storage medium is provided, which stores a computer program. When the computer program is executed by a processor, a method for correcting a density curve based on a density rock physics model is implemented.

[0051] The method comprises the following steps: obtaining a density rock physics model when a density curve is distorted; wherein the density rock physics model is used to represent the corresponding relationship between the density in the density curve and the volume components of a plurality of rock components and the density of the plurality of rock components; determining the density corresponding to each rock component in the density curve according to a non-expanded section curve in the density curve; determining a new density curve according to the density rock physics model and the density corresponding to each rock component; and determining a corrected density curve according to the new density curve.

[0052] In some embodiments, the density rock physics model may be expressed as: Among them, ρ is used to represent the density in the density curve, N is used to represent the total number of multiple rock components, and f i It is used to represent the volume component of the i-th rock component, ρ i Used to represent the density of the i-th rock component.

[0053] In some embodiments, the rock components include: mineral components, pore fluid components, and the density corresponding to each rock component in the density curve is determined according to the non-expansion section curve in the density curve, including: determining the non-reservoir section mineral comprehensive density corresponding to the non-reservoir section mineral component according to the mineral density corresponding to the non-reservoir section mineral component in the non-expansion section curve; adjusting the reservoir section mineral density with a porosity less than a preset value according to the non-reservoir section mineral comprehensive density, until the difference between the target density obtained by substituting the non-reservoir section mineral comprehensive density and the reservoir section mineral density with a porosity less than a preset value into the density rock physics model and the corresponding density in the density curve is less than the preset difference, and the reservoir section mineral density corresponding to the target density is used as the target reservoir section mineral density; determining the reservoir section pore fluid component density and the non-reservoir section pore fluid component density according to the preset oil and gas saturation curve.

[0054] In some embodiments, the new density curve is determined based on the density rock physics model and the density corresponding to each rock component, including: substituting the mineral density of the non-reservoir section, the pore fluid component density of the non-reservoir section, the mineral density of the target reservoir section, and the pore fluid component density of the reservoir section into the density rock physics model to obtain a new density curve.

[0055] In some embodiments, determining a corrected density curve based on the new density curve includes at least one of the following: obtaining a first density distribution of a non-expanded section corresponding to the density curve and a second density distribution of the new density curve in the non-expanded section, and when the difference between the first density distribution and the second density distribution is less than the first difference, using the new density curve as the corrected density curve; obtaining a third density distribution of an expanded section corresponding to the density curve and a fourth density distribution of the new density curve in the expanded section, and when the density in the third density distribution is less than the density at the same depth in the fourth density distribution and the total number of densities is greater than a preset total number, using the new density curve as the corrected density curve; comparing the density in the new density curve with the actual density of the core at the same depth, and when the density change trend of the new density curve is consistent with the change trend of the actual density of the core, using the new density curve as the corrected density curve.

[0056] Example 5

[0057] Figure 3 , Figure 4 A reference schematic diagram of a method for correcting a density curve based on a density rock physics model according to an embodiment of the present invention is shown.

[0058] Combination Figure 3 In the expansion section, the modeled density (i.e., the density in the corrected density curve) is generally higher than the original density (i.e., the density in the uncorrected density curve), and the low-density feature in the expansion section is a distortion. Therefore, it can be considered that the corrected density curve is better than the uncorrected density curve.

[0059] Combination Figure 4 , the modeled density is more consistent with the core density distribution, so it is believed that the corrected density curve is better than the uncorrected density curve.

[0060] For other detailed descriptions of this exemplary embodiment, reference may be made to the corresponding descriptions in the aforementioned embodiments, which will not be repeated here.

[0061] The embodiments of the present invention have been described above, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The terms used herein are selected to best explain the principles of the embodiments, practical applications, or technical improvements to the technology in the market, or to enable other persons of ordinary skill in the art to understand the embodiments disclosed herein.

Claims

1. A correction method for density curve based on density rock physics model, It is characterized in that The correction method comprises: In the case where the density curve is distorted, a density rock physics model is obtained; wherein the density rock physics model is used to represent the corresponding relationship between the density in the density curve and the volume components of multiple rock components and the density of the multiple rock components; Determine the density corresponding to each rock component in the density curve according to the non-expanded section curve in the density curve; Determine a new density curve according to the density rock physics model and the density corresponding to each rock component; A corrected density curve is determined based on the new density curve.

2. The calibration method according to claim 1, It is characterized in that The density rock physics model can be expressed as: Among them, ρ is used to represent the density in the density curve, N is used to represent the total number of multiple rock components, and f i It is used to represent the volume component of the i-th rock component, ρ i Used to represent the density of the i-th rock component.

3. The calibration method according to claim 1, It is characterized in that The rock components include: mineral components and pore fluid components. Determining the density corresponding to each rock component in the density curve according to the non-expanded section curve in the density curve includes: Determine the comprehensive density of non-reservoir section minerals corresponding to the non-reservoir section mineral components according to the mineral density corresponding to the non-reservoir section mineral components in the non-expanded section curve; According to the comprehensive mineral density of the non-reservoir section, the mineral density of the reservoir section with a porosity less than a preset value is adjusted until the difference between the target density obtained by substituting the comprehensive mineral density of the non-reservoir section and the mineral density of the reservoir section with a porosity less than the preset value into the density rock physics model and the corresponding density in the density curve is less than the preset difference, and the mineral density of the reservoir section corresponding to the target density is used as the target mineral density of the reservoir section; According to the preset oil and gas saturation curve, the density of the pore fluid components in the reservoir section and the density of the pore fluid components in the non-reservoir section are determined.

4. The calibration method according to claim 3, It is characterized in that Determining a new density curve according to the density rock physics model and the density corresponding to each rock component includes: Substituting the mineral density of the non-reservoir section, the density of the pore fluid component of the non-reservoir section, the mineral density of the target reservoir section, and the density of the pore fluid component of the reservoir section into the density rock physics model, a new density curve is obtained.

5. The calibration method according to claim 1, It is characterized in that Determining a corrected density curve according to the new density curve includes at least one of the following: Acquire a first density distribution of a non-expanded diameter section corresponding to the density curve and a second density distribution of the new density curve in the non-expanded diameter section, and when the difference between the first density distribution and the second density distribution is less than the first difference, use the new density curve as a corrected density curve; Obtaining a third density distribution of the diameter expansion section corresponding to the density curve and a fourth density distribution of the new density curve in the diameter expansion section, and taking the new density curve as a corrected density curve when the total number of densities at the same depth in the third density distribution and the density at the same depth in the fourth density distribution is greater than a preset total number; The density in the new density curve is compared with the density actually measured at the same depth. If the density change trend of the new density curve is consistent with the change trend of the actually measured density of the core, the new density curve is used as the corrected density curve.

6. A correction device for density curve based on density rock physics model, It is characterized in that The correction device comprises: A model acquisition module, used for acquiring a density rock physics model when the density curve is distorted; wherein the density rock physics model is used for representing the correspondence between the density in the density curve and the volume components of multiple rock components and the density of multiple rock components; A density determination module, used for determining the density corresponding to each rock component in the density curve according to the non-expanded section curve in the density curve; A curve determination module, used to determine a new density curve according to the density rock physics model and the density corresponding to each rock component; The correction module is used to determine a corrected density curve according to the new density curve.

7. The calibration device according to claim 6, It is characterized in that The density rock physics model can be expressed as: Among them, ρ is used to represent the density in the density curve, N is used to represent the total number of multiple rock components, and f i It is used to represent the volume component of the i-th rock component, ρ i Used to represent the density of the i-th rock component.

8. The calibration device according to claim 6, It is characterized in that The rock components include: mineral components and pore fluid components. The density determination module is also used to determine the non-reservoir section mineral comprehensive density corresponding to the non-reservoir section mineral component according to the mineral density corresponding to the non-reservoir section mineral component in the non-expansion section curve; adjust the reservoir section mineral density with a porosity less than a preset value according to the non-reservoir section mineral comprehensive density, until the difference between the target density obtained by substituting the non-reservoir section mineral comprehensive density and the reservoir section mineral density with a porosity less than the preset value into the density rock physics model and the corresponding density in the density curve is less than the preset difference, and the reservoir section mineral density corresponding to the target density is used as the target reservoir section mineral density; determine the reservoir section pore fluid component density and the non-reservoir section pore fluid component density according to the preset oil and gas saturation curve.

9. The calibration device according to claim 8, It is characterized in that The curve determination module is also used to substitute the mineral density of the non-reservoir section, the pore fluid component density of the non-reservoir section, the mineral density of the target reservoir section, and the pore fluid component density of the reservoir section into the density rock physics model to obtain a new density curve.

10. The calibration device according to claim 6, It is characterized in that The correction module is also used to perform at least one of the following: obtaining a first density distribution of a non-expanded section corresponding to the density curve and a second density distribution of the new density curve in the non-expanded section, and when the difference between the first density distribution and the second density distribution is less than the first difference, using the new density curve as a corrected density curve; obtaining a third density distribution of an expanded section corresponding to the density curve and a fourth density distribution of the new density curve in the expanded section, and when the density in the third density distribution is less than the density at the same depth in the fourth density distribution and the total number of densities is greater than a preset total number, using the new density curve as a corrected density curve; comparing the density in the new density curve with the actual density measured in the core at the same depth, and when the density change trend of the new density curve is consistent with the change trend of the actual density measured in the core, using the new density curve as a corrected density curve.

11. An electronic device, It is characterized in that The electronic device comprises: A memory storing executable instructions; A processor, wherein the processor runs the executable instructions in the memory to implement the correction method according to any one of claims 1 to 5.

12. A computer-readable storage medium storing a computer program, wherein the computer program, when executed by a processor, implements the correction method according to any one of claims 1 to 5.

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