Methods, devices and electronic equipment for permeability correction of sandstone and conglomerate

Abstract

This invention discloses a method, apparatus, and electronic device for permeability correction of sandstone and conglomerate. The method includes: obtaining the target porosity and target logging value of the target sandstone and conglomerate; determining the target flow element index and target clay content of the target sandstone and conglomerate based on the target logging value; determining the initial permeability of the target sandstone and conglomerate based on the target porosity and target flow element index; and correcting the initial permeability based on the target porosity and target clay content to obtain the target permeability of the target sandstone and conglomerate. This invention solves the technical problem in related technologies where the accuracy of the permeability obtained when determining the permeability of sandstone and conglomerate is low, and the permeability differs significantly from the actual permeability.

Description

Technical Field

[0001] This invention relates to the field of rock strata exploration, and more specifically, to a method, apparatus, and electronic device for correcting the permeability of sandstone and conglomerate. Background Technology

[0002] Sandstone and conglomerate reservoirs are widely developed in my country, with an exploration area of ​​tens of thousands of square kilometers. These reservoirs are large in scale and rich in reserves, and have become the main oil and gas reservoirs for exploration and development in major oilfields across the country. However, long-term sedimentary processes, diagenesis, and the effects of weathering and hydrothermal activity can generate clay minerals, which can clog the pore structure of the rock, reduce the permeability of the reservoir, and make it difficult to evaluate the effectiveness of the reservoir.

[0003] Currently, the determination of clay content in sandstone and conglomerate is mostly based on whole-rock analysis experiments and single-parameter formula calculations. There is no clear and feasible technical means for permeability correction of clay-bearing rocks.

[0004] There is currently no effective solution to the above problems. Summary of the Invention

[0005] This invention provides a method, apparatus, and electronic device for correcting the permeability of sandstone and conglomerate, to at least solve the technical problem in related technologies where the accuracy of the permeability obtained when determining the permeability of sandstone and conglomerate is low and differs significantly from the actual permeability.

[0006] According to one aspect of the present invention, a method for correcting the permeability of conglomerate is provided, comprising: obtaining a target porosity and a target logging value of a target conglomerate; determining a target flow element index and a target clay content of the target conglomerate based on the target logging value; determining an initial permeability of the target conglomerate based on the target porosity and the target flow element index; and correcting the initial permeability based on the target porosity and the target clay content to obtain a target permeability of the target conglomerate.

[0007] Optionally, determining the initial permeability of the target sandstone based on the target porosity and the target flow unit index includes: determining a target cumulative frequency based on the target flow unit index and a target slope of the target cumulative frequency; determining a target flow unit type of the target sandstone and a permeability formula corresponding to the target flow unit type based on the target slope; and substituting the target porosity into the permeability formula to determine the initial permeability of the target sandstone.

[0008] Optionally, before determining the target flow unit type of the target sandstone and the permeability formula corresponding to the target flow unit type based on the target slope, the method further includes: determining the experimental porosity, experimental permeability, experimental flow unit index, experimental cumulative frequency based on the experimental flow unit index, and the experimental slope of the experimental cumulative frequency of the experimental sandstone; classifying multiple flow unit types based on the experimental cumulative frequency based on the experimental flow unit index and the experimental slope of the experimental cumulative frequency, wherein the target flow unit type is one of the multiple flow unit types; and determining the permeability formula corresponding to each of the multiple flow unit types based on the experimental porosity, the experimental permeability, and the experimental flow unit index.

[0009] Optionally, determining the target flow unit index of the target sandstone based on the target logging value includes: determining a first predetermined coefficient when the target logging value includes a target sonic logging value, a target neutron logging value, a target deep lateral logging value, and a target shallow lateral logging value; and determining the target flow unit index of the target sandstone based on the first predetermined coefficient, the target sonic logging value, the target neutron logging value, the target deep lateral logging value, and the target shallow lateral logging value.

[0010] Optionally, determining the target clay content of the target sandstone based on the target logging values ​​includes: when the target logging values ​​include target sonic logging values, target neutron logging values, target deep lateral logging values, and target natural gamma logging values, determining the initial clay content of the target sandstone based on the target sonic logging values, the target neutron logging values, the target deep lateral logging values, and the target natural gamma logging values; normalizing the initial clay content to obtain a normalized clay content; and determining the target clay content of the target sandstone based on a second predetermined coefficient and the normalized clay content.

[0011] Optionally, the step of correcting the initial permeability based on the target porosity and the target clay content to obtain the target permeability of the target sandstone includes: determining the target seepage radius; and correcting the initial permeability based on the target seepage radius, the target porosity, and the target clay content to obtain the target permeability of the target sandstone.

[0012] Optionally, the step of correcting the initial permeability based on the target seepage radius, the target porosity, and the target clay content to obtain the target permeability of the target sandstone includes: determining an initial theoretical permeability formula; correcting the initial theoretical permeability formula to a target theoretical permeability formula based on the target seepage radius; and substituting the initial permeability and the target clay content into the target theoretical permeability formula to obtain the target permeability of the target sandstone.

[0013] According to one aspect of the present invention, a sandstone permeability correction device is provided, comprising: an acquisition module for acquiring a target porosity and a target logging value of a target sandstone; a first determination module for determining a target flow unit index and a target clay content of the target sandstone based on the target logging value; a second determination module for determining an initial permeability of the target sandstone based on the target porosity and the target flow unit index; and a third determination module for correcting the initial permeability based on the target porosity and the target clay content to obtain the target permeability of the target sandstone.

[0014] According to one aspect of the present invention, an electronic device is provided, comprising: a processor; and a memory for storing processor-executable instructions; wherein the processor is configured to execute the instructions to implement the sandstone permeability correction method described in any of the preceding claims.

[0015] According to one aspect of the present invention, a computer-readable storage medium is provided, which, when the instructions in the computer-readable storage medium are executed by a processor of an electronic device, enables the electronic device to perform the sandstone permeability correction method described in any of the preceding claims.

[0016] In this embodiment of the invention, the target porosity and target logging value of the target sandstone are obtained. Based on the target logging value, the target flow unit index and target clay content of the target sandstone are determined. Based on the target porosity and target flow unit index, the initial permeability of the target sandstone is determined. Based on the target porosity and target clay content, the initial permeability is corrected, and finally, the target permeability of the target sandstone is obtained. Because the target permeability is obtained by correcting the initial permeability, the correction of the initial permeability is achieved. Moreover, since the correction is based on the target porosity and target clay content, the influence of clay content is taken into account, making the correction more accurate. This solves the technical problem in related technologies where the accuracy of the permeability obtained when determining the permeability of sandstone is low and differs significantly from the actual permeability. Attached Figure Description

[0017] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this application, illustrate exemplary embodiments of the invention and, together with their description, serve to explain the invention and do not constitute an undue limitation thereof. In the drawings:

[0018] Figure 1 This is a flowchart of a method for correcting the permeability of sandstone and conglomerate according to an embodiment of the present invention;

[0019] Figure 2 This is a graph showing the relationship between clay content and clay index provided by an optional embodiment of the present invention;

[0020] Figure 3 This is a schematic diagram of the target cumulative frequency provided by an optional embodiment of the present invention;

[0021] Figure 4 This is a schematic diagram of multiple flow unit types provided in optional embodiments of the present invention;

[0022] Figure 5 This is a schematic diagram of the effective seepage radius provided by an optional embodiment of the present invention;

[0023] Figure 6 This is a schematic diagram of the permeability and analytical permeability of sandstone before and after correction, provided by an optional embodiment of the present invention;

[0024] Figure 7 This is a schematic diagram illustrating the actual application effect provided by an optional embodiment of the present invention;

[0025] Figure 8 This is a structural block diagram of a sandstone permeability correction device according to an embodiment of the present invention. Detailed Implementation

[0026] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0027] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0028] Example 1

[0029] According to an embodiment of the present invention, an embodiment of a method for correcting the permeability of sandstone and conglomerate is provided. It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions. Furthermore, although a logical order is shown in the flowchart, in some cases, the steps shown or described may be executed in a different order than that shown here.

[0030] Figure 1 This is a flowchart of a sandstone permeability correction method according to an embodiment of the present invention, such as... Figure 1 As shown, the method includes the following steps:

[0031] Step S102: Obtain the target porosity and target logging value of the target sandstone and conglomerate.

[0032] Step S104: Based on the target logging values, determine the target flow unit index and target clay content of the target sandstone and conglomerate.

[0033] Step S106: Determine the initial permeability of the target sandstone and conglomerate based on the target porosity and the target flow unit index;

[0034] Step S108: Based on the target porosity and target clay content, correct the initial permeability to obtain the target permeability of the target sandstone.

[0035] Through the above steps, the target porosity and target logging values ​​of the target sandstone and conglomerate are obtained. Based on the target logging values, the target flow unit index and target clay content of the target sandstone and conglomerate are determined. Based on the target porosity and target flow unit index, the initial permeability of the target sandstone and conglomerate is determined. Based on the target porosity and target clay content, the initial permeability is corrected, and finally, the target permeability of the target sandstone and conglomerate is obtained. Because the target permeability is obtained by correcting the initial permeability, the correction of the initial permeability is achieved. Moreover, since the correction is based on the target porosity and target clay content, the influence of clay content is taken into account, making the correction more accurate. This solves the technical problem in related technologies where the accuracy of the permeability obtained when determining the permeability of sandstone and conglomerate is low, and the permeability differs significantly from the actual permeability.

[0036] As an optional embodiment, the target porosity and target logging values ​​of the target sandstone and conglomerate are obtained. The target sandstone and conglomerate is the sandstone and conglomerate reservoir whose permeability is to be detected. The target porosity can be a fitted value of the porosity in the target sandstone and conglomerate. The target logging values ​​can include target sonic logging values, target neutron logging values, target deep lateral logging values, target shallow lateral logging values, target natural gamma logging values, etc. The target deep lateral logging values ​​reflect the original formation resistivity, used to more accurately detect the permeability of the target sandstone and conglomerate.

[0037] As an optional embodiment, the target flow unit index and target clay content of the target sandstone are determined based on the target logging values. The target flow unit index of the target sandstone is determined based on the target logging values, and the initial permeability can be determined based on the target flow unit index. It should be noted that in this application, correlation analysis is performed a priori using experimental data such as porosity, average capillary radius, maximum pore throat radius, and clay content with permeability data to determine that clay content is the main controlling factor for permeability reduction. Therefore, the initial permeability determined based on the target flow unit index can be corrected based on the clay content. This accurately controls the influencing factor of clay content. Determining the target clay content of the target sandstone based on the target logging values ​​makes the subsequent correction of the initial permeability more accurate.

[0038] As an optional embodiment, determining the target flow unit index of the target sandstone and conglomerate based on the target logging values ​​can be achieved in various ways. For example, it can be done as follows: when the target logging values ​​include target sonic logging values, target neutron logging values, target deep lateral logging values, and target shallow lateral logging values, a first predetermined coefficient is determined; based on the first predetermined coefficient, the target sonic logging values, the target neutron logging values, the target deep lateral logging values, and the target shallow lateral logging values, the target flow unit index of the target sandstone and conglomerate is determined. The first predetermined coefficient can be obtained by optimal fitting of experimental data. The process of determining the target flow unit index of the target sandstone and conglomerate based on the first predetermined coefficient, the target sonic logging values, the target neutron logging values, the target deep lateral logging values, and the target shallow lateral logging values ​​will be described in detail in the optional embodiments below, and will not be repeated here. The target flow unit index can be obtained using the first predetermined coefficient and the target logging values, which allows for convenient and quick determination of the initial permeability, improving the efficiency of permeability correction in this application.

[0039] As an optional embodiment, determining the target clay content of the target sandstone and conglomerate based on the target logging values ​​can include various methods. For example, it can be done as follows: when the target logging values ​​include target sonic logging values, target neutron logging values, target deep lateral logging values, and target natural gamma logging values, the initial clay content of the target sandstone and conglomerate can be determined based on these values. To improve the accuracy of the determined target clay content, the initial clay content can be normalized to fall within the range of 0-100, resulting in a normalized clay content. The target clay content of the target sandstone and conglomerate can then be determined based on a second predetermined coefficient and the normalized clay content. The second predetermined coefficient can be obtained through optimal fitting of experimental data. The process for determining the target clay content described above will be detailed in the optional embodiments below and will not be elaborated further here. The target clay content can be obtained by using the second predetermined coefficient and the target logging value, which improves the efficiency of permeability correction in this application and ensures that the target clay content can be determined quickly and accurately.

[0040] As an optional embodiment, the initial permeability of the target sandstone can be determined based on the target porosity and the target flow unit index, so that the initial permeability can be corrected.

[0041] As an optional embodiment, there are many ways to determine the initial permeability of a target sandstone conglomerate based on target porosity and target flow unit index. For example, the following method can be used: Based on the target flow unit index, determine the target cumulative frequency and the target slope of the target cumulative frequency; based on the target slope, determine the target flow unit type of the target sandstone conglomerate and the corresponding permeability formula; substitute the target porosity into the permeability formula to determine the initial permeability of the target sandstone conglomerate. That is, the reservoir type of the target sandstone conglomerate reservoir can be determined based on the target slope of the target cumulative frequency. Different reservoir types correspond to different permeability formulas. Substituting the target porosity into the corresponding permeability formula determines the initial permeability of the target sandstone conglomerate. Obtaining the initial permeability in this way ensures that the obtained initial permeability is based on both subjective experience and objective analysis, making the obtained initial permeability more accurate.

[0042] Optionally, before determining the target flow unit type of the target conglomerate and the corresponding permeability formula, the process may include determining multiple flow unit types and their corresponding permeability formulas. For example, this can be achieved by determining the experimental porosity, experimental permeability, experimental flow unit index, cumulative experimental frequency based on the experimental flow unit index, and the experimental slope of the cumulative experimental frequency for the experimental conglomerate. Here, the experimental conglomerate can be understood as a conglomerate reservoir where multiple data points are known; therefore, patterns can be found among these data points based on their relationships. Multiple flow unit types are defined based on the cumulative experimental frequency and its experimental slope, with the target flow unit type being one of these multiple flow unit types. When defining multiple flow unit types, different levels of refinement can be applied based on the actual application and scenario. In scenarios requiring higher precision, more flow unit types can be defined, making this application more flexible. After defining multiple flow unit types, the permeability formulas corresponding to each flow unit type can be determined based on the experimental porosity, experimental permeability, and experimental flow unit index. Therefore, the reservoir type of the target sandstone and conglomerate can be determined among multiple flow unit types based on the target slope of the target cumulative frequency. By substituting the target porosity into the corresponding permeability formula, the initial permeability of the target sandstone and conglomerate can be determined. This method is convenient, quick, and can accelerate the permeability determination process.

[0043] As an optional embodiment, the initial permeability is corrected based on the target porosity and target clay content to obtain the target permeability of the target sandstone / conglomerate. In this process, the target seepage radius can be determined first; based on the target seepage radius, target porosity, and target clay content, the initial permeability is corrected to obtain the target permeability of the target sandstone / conglomerate. Because clay content has a significant impact on reservoir permeability, clay particles distributed in the pore space form a clay film, leading to a reduction in the cross-sectional area of ​​the pore capillary bundles and blocking some throats, thus reducing pore permeability. When considering the influencing factor of clay content, considering the target seepage radius allows for a more accurate and comprehensive assessment of the target permeability, resulting in a more precise final target permeability.

[0044] As an optional embodiment, the target permeability of the target sandstone is obtained by correcting the initial permeability based on the target seepage radius, target porosity, and target clay content. This includes: determining an initial theoretical permeability formula; correcting the initial theoretical permeability formula to a target theoretical permeability formula based on the target seepage radius; and substituting the initial permeability and target clay content into the target theoretical permeability formula to obtain the target permeability of the target sandstone. The process of obtaining the target permeability of the target sandstone is described in the optional embodiments below and will not be repeated here. By correcting the formula and substituting the initial permeability and target clay content into the target theoretical permeability formula to obtain the target permeability of the target sandstone, the obtained target permeability is not only based on evidence and accurate, but also speeds up the efficiency of correcting the initial permeability and obtaining the target permeability, making the method provided in this application more efficient.

[0045] Based on the above embodiments and optional embodiments, an optional implementation method is provided, which is described in detail below.

[0046] An optional embodiment of this invention provides a permeability correction method for clay-bearing sandstone with a membrane-like pore structure. This optional embodiment addresses the influence of pore structure and clay distribution on the seepage capacity of clay-bearing sandstone with a membrane-like pore throat structure. It determines a multiple regression formula for continuously calculating the flow unit index, first eliminating the influence of pore structure on permeability, then quantitatively calculating the reservoir clay content using a multi-curve combination method. By analyzing the rock seepage mechanism, a permeability correction formula for the clay-bearing membrane-like pore throat structure is determined. Comparison of the calculated results with experimentally analyzed permeability shows good correlation and high calculation accuracy, providing a new approach for permeability correction of clay-bearing rocks. The optional embodiment of this invention is described in detail below:

[0047] It should be noted beforehand that porosity, mercury injection, and whole-rock tests were conducted according to the domestic industry standard for core analysis SY / T 5336-2006. Correlation analysis was performed between the analyzed experimental data (porosity, average capillary radius, maximum pore throat radius, clay content, etc.) and permeability data to determine that clay content is the main controlling factor for permeability reduction. Therefore, permeability was corrected based on clay content.

[0048] S1, obtain the target porosity and target logging value of the target sandstone and conglomerate. The target sandstone and conglomerate is the sandstone and conglomerate reservoir whose permeability is to be detected. The target logging value includes the target sonic logging value, the target neutron logging value, the target deep lateral logging value, the target shallow lateral logging value, and the target natural gamma logging value.

[0049] S2, based on the target logging values, determine the target flow unit index of the target sandstone and conglomerate;

[0050] S2.1, Determine the first predetermined coefficients, a, b, c, d;

[0051] S2.2, based on the first predetermined coefficient, the target sonic logging value, the target neutron logging value, the target deep lateral logging value, and the target shallow lateral logging value, determine the target flow unit index of the target sandstone.

[0052] As shown in formula (1), the target flow element index FZI of the target sandstone and conglomerate is determined:

[0053]

[0054] In the formula, a, b, c, and d are all coefficients, namely the first predetermined coefficients mentioned above, which are obtained by optimal fitting of experimental data. AC is the sonic logging value, in μs / ft; CNL is the neutron logging value, in %; RT and RI are the deep lateral and shallow lateral logging values, in Ω·m.

[0055] S3, based on the target logging values, determine the target clay content of the target sandstone and conglomerate;

[0056] S3.1, Based on the target sonic logging value, target neutron logging value, target deep lateral logging value and target natural gamma logging value, determine the initial clay content of the target sandstone and conglomerate;

[0057] As shown in formula (2), the initial clay content NZ of the target sandstone and conglomerate is determined, which can also be called the clay content index:

[0058]

[0059] In the formula, AC is the sonic logging value in μs / ft; CNL is the neutron logging value in %; GR is the natural gamma logging value in API; and RT is the deep lateral logging value in Ω·m.

[0060] S3.2, normalize the initial clay content to obtain the normalized clay content;

[0061] As shown in formula (3), the initial clay content is normalized to obtain the normalized clay content, which is distributed in the range of 0-100.

[0062]

[0063] In the formula, NZ max The maximum value of the clay index; NZ min This is the minimum value of the clay index.

[0064] S3.3, Based on the second predetermined coefficient and the normalized clay content, determine the target clay content of the target sandstone and conglomerate.

[0065] As shown in formula (4), the target clay content V of the target sandstone and conglomerate is determined. NT ;

[0066] V NT =i×NZ * +j (4)

[0067] In the formula, i and j are both coefficients, namely the second predetermined coefficients mentioned above, which are obtained by optimal fitting of experimental data. Figure 2 This is a graph showing the relationship between clay content and clay index provided by an optional embodiment of the present invention, such as... Figure 2 As shown, the coefficients i and j can be obtained from the data.

[0068] It should be noted that the clay content index NZ was determined based on the above data as follows: According to the physicochemical properties of clay minerals, well logging curve response characteristics of clay-bearing sandstone and conglomerate were analyzed. The natural gamma logging value is mainly affected by clay minerals and their adsorbed radioactive elements; when the clay content is high, the natural gamma increases. Since the acoustic transit time of mudstone is greater than that of sandstone skeleton, the acoustic transit time is positively correlated with the clay mineral content. Higher clay content indicates more clay mineral particles and more ions adsorbed on their surface. Under the influence of an external electric field, a large number of ions adsorbed on the particle surface will move along the surface to conduct current, thereby reducing the rock resistivity. When clay minerals adhere to the pore surface of the rock, a bound water clay film will form on its surface, increasing the rock's hydrogen index and leading to a larger compensated neutron logging value. Therefore, the clay content index NZ was determined using sensitive curves such as natural gamma, neutron, and acoustic logging.

[0069] S4. Determine the initial permeability of the target sandstone and conglomerate based on the target porosity and the target flow unit index.

[0070] S4.1, Based on the target flow unit index, determine the target cumulative frequency based on the target flow unit index, and the target slope of the target cumulative frequency;

[0071] Figure 3 This is a schematic diagram of the target cumulative frequency provided by an optional embodiment of the present invention, such as... Figure 3 As shown, the target slope of the target cumulative frequency can be seen from the target cumulative frequency.

[0072] S4.2, Based on the target slope, determine the target flow unit type of the target sandstone and the permeability formula corresponding to the target flow unit type;

[0073] S4.3, Substitute the target porosity into the permeability formula to determine the initial permeability K of the target sandstone and conglomerate;

[0074] It should be noted that before determining the target flow unit type of the target sandstone and conglomerate and the permeability formula corresponding to the target flow unit type based on the target slope, the process also includes: dividing multiple flow unit types and determining the permeability formula corresponding to each of the multiple flow unit types.

[0075] S4.2.1, determine the experimental porosity, experimental permeability, experimental flow unit index, experimental cumulative frequency based on the experimental flow unit index, and experimental slope of the experimental cumulative frequency for the experimental sandstone and conglomerate.

[0076] It should be noted that the experimental flow element index (FZI) can be calculated using the formula determined by Kozeny and Carmen based on the principles of seepage mechanics. The formula for calculating the experimental flow element index FZI is shown in (5):

[0077]

[0078] In the formula, K is the experimentally analyzed permeability, 10 -3 μm 2 ;φ e For experimental analysis of effective porosity, decimal; F s τ is the shape factor; τ is the tortuosity of the porous medium, a decimal; F s τ 2 is the Kozeny constant, which is a variable constant that varies between flow units, but remains constant within a flow unit. In actual reservoirs, its value ranges from 5 to 100; S gv Specific surface area per unit particle volume (μm) -1 ).

[0079] The experimental flow unit index was calculated, and a cumulative frequency plot of the experimental flow unit index was plotted. Figure 4 This is a schematic diagram of multiple flow unit types provided by optional embodiments of the present invention, such as... Figure 4 As shown, the slopes of Class I, Class II, and Class III reservoirs are the experimental slopes corresponding to the cumulative experimental frequencies of different experimental sandstones.

[0080] S4.2.2, based on the experimental cumulative frequency and the experimental slope of the experimental cumulative frequency according to the experimental flow unit index, multiple flow unit types are classified, for example, classified as... Figure 4 The reservoirs in the study area are divided into three types of flow units: Type I, Type II, and Type III reservoirs.

[0081] S4.2.3, based on experimental porosity, experimental permeability, and experimental flow unit index, determine the permeability formulas corresponding to each of the multiple flow unit types, that is, determine the permeability formulas corresponding to different flow units according to three categories of standards.

[0082] Examples of flow unit types and their corresponding permeability formulas are provided. Table 1 shows the classification criteria for each parameter of the flow unit. As shown in Table 1, the flow unit types and their corresponding permeability formulas are as follows. The target flow unit type is one of the following three types.

[0083] Table 1

[0084]

[0085] The permeability formula for the first type of flow unit is:

[0086] R 2 =0.7546

[0087] The formula for the permeability of the second type of flow unit is:

[0088] R 2 =0.6039

[0089] The formula for the permeability of the third type of flow unit is:

[0090] R 2 =0.7639

[0091] In the formula, K is the permeability, 10 -3 μm 2 ; Porosity, in percentages (%)

[0092] S5. Based on the target porosity and target clay content, the initial permeability is corrected to obtain the target permeability of the target sandstone.

[0093] S5.1, Determine the target seepage radius;

[0094] When there is dispersed clay or structural clay in the reservoir pore throat space, assuming that these clays adhere to the surface of the pore throat space to form a clay film, the effective seepage radius of the fluid is reduced to rd, that is, the target seepage radius is rd. Figure 5 This is a schematic diagram of the effective seepage radius provided by an optional embodiment of the present invention, as shown below. Figure 5 As shown, the target seepage radius is rd.

[0095] S5.2, Determine the initial theoretical penetration rate formula;

[0096] Based on the seepage mechanism, according to Poiseuille's equation and Darcy's law, for pure rock pore capillary, when the fluid in the reservoir seeps horizontally in a radial direction, the permeability formula is as shown in formula (6):

[0097]

[0098] In the formula, r is the capillary radius; μ is the fluid viscosity; n is the number of capillaries; Δp is the pressure difference between the two ends of the capillary; τ is the capillary tortuosity; q is the flow rate; and A is the cross-sectional area of ​​the capillary.

[0099] S5.3, Based on the target seepage radius, correct the initial theoretical permeability formula to the target theoretical permeability formula;

[0100] Based on the target seepage radius rd, the permeability formula after clay content correction is obtained, as shown in formula (7):

[0101]

[0102] According to the rock physics volume formula, the relationship between clay content and porosity is shown in formula (8):

[0103]

[0104] The permeability of clay after correction is shown in formula (9):

[0105]

[0106] In the formula, K is the permeability, 10 -3 μm 2 ;k are all empirical coefficients, adjusted according to the research block;V NT Clay content, in %; Porosity, in percentages (%)

[0107] S5.4 Substitute the initial permeability and the target clay content into the target theoretical permeability formula to obtain the target permeability of the target sandstone.

[0108] The permeability calculation result K obtained in step S4 and the clay content calculation result V obtained in step S3 are used together. NT Substituting into formula (9), the corrected permeability can be obtained. By comparing the permeability with the experimental analysis, the calculation results of this formula are more relevant and more accurate.

[0109] Figure 6 This is a schematic diagram of the permeability and analytical permeability of sandstone before and after correction, provided by an optional embodiment of the present invention, as shown below. Figure 6 As shown, the corrected permeability can be obtained. By comparing the permeability with experimental analysis, the results calculated by this formula have a higher correlation and are more accurate.

[0110] Figure 7 This is a schematic diagram illustrating the actual application effect provided by an optional embodiment of the present invention, such as... Figure 7 As shown, Figure 7 In the figure, the first line represents the natural gamma curve, the second the depth line, the third the lithological profile, the fourth the deep and shallow lateral resistivity curves, the fifth the three-porosity curve, the sixth the calculated porosity curve (circular dots represent experimentally analyzed porosity), the seventh the FZI curve calculated from experimental analysis and the fitted formula, the eighth the clay content line, the ninth the permeability calculated before correction (circular dots represent experimentally analyzed permeability), and the tenth the permeability calculated after correction (circular dots represent experimentally analyzed permeability). In the figure, the calculated permeability before correction is mostly higher than the permeability analyzed by rock physics experiments. The permeability calculated using the clay correction formula agrees well with the analyzed permeability, thus verifying the reliability of this method.

[0111] Through the above optional implementation methods, at least the following beneficial effects can be achieved: Regarding the influence of pore structure and clay distribution on seepage capacity in clay-bearing sandstone and conglomerate, multiple conventional permeability calculation formulas are determined using the flow element method, eliminating the influence of pore structure on permeability. The reservoir clay content is quantitatively calculated using well logging curves, the rock pore throat seepage mechanism is analyzed, and a permeability correction formula for clay-film pore throat structures is determined. The calculated results show good correlation with experimentally analyzed permeability, providing a new approach for permeability correction in clay-film pore-structured sandstone and conglomerate. This method is of great significance for evaluating the effectiveness of clay-bearing sandstone and conglomerate reservoirs. Starting from the study of seepage mechanisms, this method has a reliable theoretical basis and provides a new method for permeability calculation in clay-bearing sandstone and conglomerate blocks lacking experimental analysis data. The calculation accuracy is significantly better than conventional permeability calculation methods.

[0112] It should be noted that, for the sake of simplicity, the foregoing method embodiments are all described as a series of actions. However, those skilled in the art should understand that the present invention is not limited to the described order of actions, because according to the present invention, some steps can be performed in other orders or simultaneously. Furthermore, those skilled in the art should also understand that the embodiments described in the specification are preferred embodiments, and the actions and modules involved are not necessarily essential to the present invention.

[0113] Through the above description of the embodiments, those skilled in the art can clearly understand that the methods according to the above embodiments can be implemented by means of software plus necessary general-purpose hardware platforms. Of course, they can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk) and includes several instructions to cause a terminal device (which may be a mobile phone, computer, server, or network device, etc.) to execute the methods of the various embodiments of the present invention.

[0114] Example 2

[0115] According to embodiments of the present invention, an apparatus for implementing the above-described method for correcting the permeability of sandstone and conglomerate is also provided. Figure 8 This is a structural block diagram of a sandstone permeability correction device according to an embodiment of the present invention, such as... Figure 8 As shown, the device includes: an acquisition module 802, a first determination module 804, a second determination module 806, and a third determination module 808. The device will be described in detail below.

[0116] The acquisition module 802 is used to acquire the target porosity and target logging value of the target sandstone and conglomerate; the first determination module 804, connected to the acquisition module 802, is used to determine the target flow unit index and target clay content of the target sandstone and conglomerate based on the target logging value; the second determination module 806, connected to the first determination module 804, is used to determine the initial permeability of the target sandstone and conglomerate based on the target porosity and target flow unit index; the third determination module 808, connected to the second determination module 806, is used to correct the initial permeability based on the target porosity and target clay content to obtain the target permeability of the target sandstone and conglomerate.

[0117] It should be noted that the above-mentioned acquisition module 802, first determination module 804, second determination module 806 and third determination module 808 correspond to steps S102 to S108 in the implementation of the sandstone permeability correction method. The multiple modules and the corresponding steps are the same in terms of implementation examples and application scenarios, but are not limited to the content disclosed in the above embodiment 1.

[0118] Example 3

[0119] According to another aspect of the present invention, an electronic device is also provided, comprising: a processor; and a memory for storing processor-executable instructions, wherein the processor is configured to execute the instructions to implement the sandstone permeability correction method of any of the above embodiments.

[0120] Example 4

[0121] According to another aspect of the present invention, a computer-readable storage medium is also provided, which, when the instructions in the computer-readable storage medium are executed by a processor of an electronic device, enables the electronic device to perform the sandstone permeability correction method described above.

[0122] The sequence numbers of the above embodiments of the present invention are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0123] In the above embodiments of the present invention, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0124] In the several embodiments provided in this application, it should be understood that the disclosed technical content can be implemented in other ways. The device embodiments described above are merely illustrative; for example, the division of units can be a logical functional division, and in actual implementation, there may be other division methods. For instance, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the displayed or discussed mutual coupling, direct coupling, or communication connection may be through some interfaces; the indirect coupling or communication connection between units or modules may be electrical or other forms.

[0125] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0126] Furthermore, the functional units in the various embodiments of the present invention can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0127] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, read-only memory (ROM), random access memory (RAM), portable hard drives, magnetic disks, or optical disks.

[0128] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for correcting the permeability of sandstone and conglomerate, characterized in that, include: Obtain the target porosity and target logging values ​​of the target sandstone and conglomerate; Based on the target logging values, the target flow unit index and target clay content of the target sandstone and conglomerate are determined. The initial permeability of the target sandstone is determined based on the target porosity and the target flow unit index. Based on the target porosity and the target clay content, the initial permeability is corrected to obtain the target permeability of the target sandstone. Among them, based on the target porosity and target clay content, the initial permeability is corrected to obtain the target permeability of the target sandstone and conglomerate, including: Determine the target seepage radius, where the target seepage radius is rd, r is the capillary radius, and d is the thickness of the clay film formed on the surface of the reservoir pore throat space by the mud. The initial theoretical penetration rate formula is determined, wherein the initial theoretical penetration rate formula is: ； In the formula, q is the flow rate, μ is the fluid viscosity, I is the penetration length, A is the cross-sectional area of ​​the capillary, Δp is the pressure difference across the capillary, n is the number of capillaries, and τ is the capillary tortuosity. Porosity; Based on the target seepage radius, the initial theoretical permeability formula is corrected to the target theoretical permeability formula, wherein the target theoretical permeability formula is: ； In the formula, This is an empirical coefficient. Clay content; Substituting the initial permeability and the target clay content into the target theoretical permeability formula, the target permeability of the target sandstone is obtained.

2. The method according to claim 1, characterized in that, Determining the initial permeability of the target sandstone based on the target porosity and the target flow unit index includes: Based on the target flow unit index, determine the target cumulative frequency based on the target flow unit index, and the target slope of the target cumulative frequency; Based on the target slope, determine the target flow unit type of the target sandstone and the permeability formula corresponding to the target flow unit type; Substituting the target porosity into the permeability formula, the initial permeability of the target sandstone is determined.

3. The method according to claim 2, characterized in that, Before determining the target flow unit type of the target sandstone and conglomerate and the permeability formula corresponding to the target flow unit type based on the target slope, the method further includes: The experimental porosity, experimental permeability, experimental flow unit index, experimental cumulative frequency based on the experimental flow unit index, and experimental slope of the experimental cumulative frequency were determined for the experimental sandstone and conglomerate. Based on the experimental cumulative frequency and the experimental slope of the experimental cumulative frequency based on the experimental flow unit index, multiple flow unit types are classified, wherein the target flow unit type is one of the multiple flow unit types. Based on the experimental porosity, the experimental permeability, and the experimental flow unit index, the permeability formulas corresponding to each of the multiple flow unit types are determined.

4. The method according to claim 1, characterized in that, Based on the target logging values, the target flow element index of the target sandstone and conglomerate is determined, including: When the target logging value includes the target sonic logging value, the target neutron logging value, the target deep lateral logging value, and the target shallow lateral logging value, a first predetermined coefficient is determined; Based on the first predetermined coefficient, the target sonic logging value, the target neutron logging value, the target deep lateral logging value, and the target shallow lateral logging value, the target flow unit index of the target sandstone is determined.

5. The method according to claim 1, characterized in that, Based on the target logging values, the target clay content of the target sandstone and conglomerate is determined, including: When the target logging values ​​include target sonic logging values, target neutron logging values, target deep lateral logging values, and target natural gamma logging values, the initial clay content of the target sandstone is determined based on the target sonic logging values, the target neutron logging values, the target deep lateral logging values, and the target natural gamma logging values. The initial clay content is normalized to obtain the normalized clay content; The target clay content of the target sandstone is determined based on the second predetermined coefficient and the normalized clay content.

6. The method according to any one of claims 1 to 5, characterized in that, The step of correcting the initial permeability based on the target porosity and the target clay content to obtain the target permeability of the target sandstone and conglomerate includes: Determine the target seepage radius; Based on the target seepage radius, the target porosity, and the target clay content, the initial permeability is corrected to obtain the target permeability of the target sandstone.

7. A permeability correction device for sandstone and conglomerate, characterized in that, include: The acquisition module is used to acquire the target porosity and target logging values ​​of the target sandstone and conglomerate. The first determining module is used to determine the target flow unit index and target clay content of the target sandstone and conglomerate based on the target logging value. The second determining module is used to determine the initial permeability of the target sandstone based on the target porosity and the target flow unit index. The third determining module is used to correct the initial permeability based on the target porosity and the target clay content to obtain the target permeability of the target sandstone. The third determining module is also used to determine the target seepage radius, wherein the target seepage radius is rd, where r is the capillary radius and d is the thickness of the clay film formed on the surface of the reservoir pore throat space by the mud. The initial theoretical penetration rate formula is determined, wherein the initial theoretical penetration rate formula is: ； In the formula, q is the flow rate, μ is the fluid viscosity, I is the penetration length, A is the cross-sectional area of ​​the capillary, Δp is the pressure difference across the capillary, n is the number of capillaries, and τ is the capillary tortuosity. Porosity; Based on the target seepage radius, the initial theoretical permeability formula is corrected to the target theoretical permeability formula, wherein the target theoretical permeability formula is: ； In the formula, This is an empirical coefficient. Clay content; Substituting the initial permeability and the target clay content into the target theoretical permeability formula, the target permeability of the target sandstone is obtained.

8. An electronic device, characterized in that, include: processor; Memory used to store the processor's executable instructions; The processor is configured to execute the instructions to implement the sandstone permeability correction method as described in any one of claims 1 to 6.

9. A computer-readable storage medium, characterized in that, When the instructions in the computer-readable storage medium are executed by the processor of the electronic device, the electronic device is able to perform the sandstone permeability correction method as described in any one of claims 1 to 6.

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