Tight reservoir pore throat proportion evaluation method and device and electronic equipment

Abstract

The invention relates to the technical field of oil and gas geological exploration, and discloses a tight reservoir pore throat proportion evaluation method and device and electronic equipment. The method comprises the following steps: carrying out a high-pressure mercury injection test experiment on a rock sample; drawing a relation curve of pore throat diameter-accumulated mercury injection saturation on the coordinate system; dividing a rapid increase section and a slow increase section of mercury injection saturation according to the change degree of the relation curve; projecting the rapid increasing section and the slow increasing section to coordinate axes where the pore throat diameter is located respectively, and obtaining the diameter range of each section of pore and throat; respectively projecting the fast increasing section and the slow increasing section to coordinate axes where the accumulated mercury injection saturation is located, and calculating the mercury saturation corresponding to each section of pore and throat; and calculating the volume proportions of pores and throats in different pore throat diameter ranges. According to the technical scheme, the pore throat proportion of the tight reservoir can be rapidly calculated according to common high-pressure mercury injection experimental data, and the method has the advantages of being easy to operate, low in experimental test cost and the like.

Description

Technical Field

[0001] The invention relates to the technical field of oil and gas geological exploration, and in particular to a method, a device and an electronic device for evaluating the pore-throat ratio of a tight reservoir. Background Art

[0002] The pore structure of tight reservoirs plays an important role in controlling the macroscopic physical properties, fluid flow and production capacity of the reservoirs. Therefore, pore structure has become one of the key contents of tight reservoir research. With the development and application of tight reservoir pore structure characterization technology, it is generally recognized that tight reservoirs develop nano- and micron-scale pore throat systems, including intergranular pores, intragranular pores, mold pores and intercrystalline pores, as well as lamellar, curved lamellar and tubular throat types. Moreover, tight reservoirs in different regions or even in the same region have obvious differences in pore throat types and sizes, reflecting the complexity of the pore structure of tight reservoirs.

[0003] At present, there are many characterization technologies for the pore structure of tight reservoirs. Various characterization methods can be classified from the perspectives of experimental means (qualitative and quantitative, direct and indirect), spatial dimensions (one-dimensional, two-dimensional, three-dimensional), and characterization scale (millimeter, micrometer, nanometer).

[0004] A search was conducted on the research methods of pore throat ratio, pore throat distribution and pore throat size of tight reservoirs, and the following literature data were obtained.

[0005] 1. Application No. CN201910126633X discloses a method for joint comparative characterization of pore throat size. After analysis, the invention cannot distinguish between pores and throats.

[0006] 2. Application No. CN2014105577227 discloses a method and device for processing microscopic pore throat data of dense sandstone. After analysis, the invention cannot distinguish between pores and throats.

[0007] 3. Application No. CN2017102385341 discloses a method for determining the pore size distribution of tight reservoirs based on mercury injection-nitrogen adsorption joint measurement data. After analysis, the invention cannot distinguish between pores and throats.

[0008] 4. The paper "Study on the pore structure of tight sandstone based on high-pressure mercury injection and nuclear magnetic resonance - taking the Shanxi Formation and Xiashihezi Formation of Sulige Gas Field as an example" combines nuclear magnetic resonance with high-pressure mercury injection technology to reflect the pore throat distribution, but this method cannot distinguish between pores and throats.

[0009] 5. The document "Application of Constant Rate Mercury Intrusion Injection in the Study of Reservoir Microscopic Pore Structure - Taking Chang 9 Reservoir in the Lower Combination of Wuqi Oilfield in Ordos Basin as an Example" uses constant rate mercury injection testing technology to distinguish and evaluate pores and throats. However, it has great disadvantages in terms of sample testing cost and testing cycle.

[0010] 6. The paper “Using Multiscale CT Imaging to Characterize the Microscopic Pore Throat Structure of Tight Sandstone” uses nano- and micron-scale CT three-dimensional reconstruction technology to reveal the microscopic pore throat characteristics of tight reservoirs. However, it has great weaknesses in terms of sample testing cost, testing cycle, and complexity of pore and throat identification process.

[0011] Regarding the identification methods of pores and throats in tight reservoirs, the main methods are cast thin sections, scanning electron microscopy, CT imaging, nuclear magnetic resonance and conventional high-pressure mercury injection analysis. They can characterize the overall distribution characteristics of pores and throats to a certain extent, but the above research methods cannot obtain the ratio relationship between the effective pores and throats of the reservoir. In quantitative research, micro-nano CT and constant-rate mercury injection technology can currently distinguish the pores and throats of tight reservoirs, but they have the disadvantages of high experimental test costs and long test cycles, and cannot be quickly and widely used in scientific research and production. Summary of the invention

[0012] The present application provides a method, device and electronic equipment for evaluating the pore-throat ratio of a tight reservoir, so as to solve the above-mentioned technical problem that the prior art is not convenient for obtaining or even unable to obtain the ratio relationship between the effective pores and throats of the tight reservoir.

[0013] According to one aspect of the present application, an embodiment provides a method for evaluating pore-throat ratio of a tight reservoir, comprising:

[0014] Conduct high-pressure mercury injection tests on rock samples to obtain data on mercury injection pressure, pore throat diameter, and mercury injection saturation;

[0015] Calculating the pore throat diameter corresponding to each of the mercury injection pressures, and drawing a relationship curve between the pore throat diameter and the cumulative mercury injection saturation on a coordinate system, wherein different pore throat diameters correspond to different cumulative mercury injection saturations;

[0016] According to the degree of change of the relationship curve, the mercury saturation is divided into a fast increasing section and a slow increasing section, wherein the fast increasing section represents the pores and the slow increasing section represents the throat;

[0017] The fast increasing section and the slow increasing section are projected onto the coordinate axis where the pore throat diameter is located, respectively, to obtain the diameter range of each section of the pore and throat;

[0018] The fast increasing section and the slow increasing section are projected onto the coordinate axis where the cumulative mercury intrusion saturation is located, respectively, and the mercury saturation corresponding to each section of the pores and throat is calculated;

[0019] Based on the mercury saturation corresponding to each section of pores and throats, the volume ratios of pores and throats in different pore throat diameter ranges are calculated.

[0020] In one embodiment, in the high-pressure mercury injection test experiment, the mercury injection pressure ranges from 0.014 MPa to 413 MPa, and the corresponding pore throat diameter ranges from 3 nm to 100 μm.

[0021] In one embodiment, the calculating of the pore throat diameters corresponding to the respective mercury injection pressures comprises:

[0022] Referring to the interfacial tension and wetting angle of the rock sample, the pore throat diameter corresponding to each mercury injection pressure is calculated using the capillary pressure formula, wherein the capillary pressure formula is as shown in Formula 1:

[0023] Pc=2σcos(θ) / r Formula 1

[0024] Where Pc is the capillary pressure; σ is the interfacial tension; θ is the wettability contact angle; and r is the pore throat radius.

[0025] In one embodiment, in the coordinate system, the pore throat diameter is set as the horizontal coordinate, and the cumulative mercury saturation is set as the vertical coordinate.

[0026] In one embodiment, according to the degree of steep change of the relationship curve, starting from the end of the larger pore throat diameter, the cumulative mercury injection saturation is divided into a fast increasing section and a slow increasing section.

[0027] In one embodiment, the volume of each section of the pores and the throat is the mercury saturation corresponding to the pores and throats.

[0028] According to one aspect of the present application, an embodiment provides a device for evaluating pore-throat ratio of a tight reservoir, comprising:

[0029] The experimental module is used to conduct high-pressure mercury injection tests on rock samples to obtain data on mercury injection pressure, pore throat diameter, and mercury injection saturation;

[0030] A drawing module, used for calculating the pore throat diameter corresponding to each mercury injection pressure, and drawing a relationship curve between the pore throat diameter and the cumulative mercury injection saturation on a coordinate system, wherein different pore throat diameters correspond to different cumulative mercury injection saturations;

[0031] A division module, used for dividing the mercury saturation into a fast increasing section and a slow increasing section according to the degree of change of the relationship curve, wherein the fast increasing section represents the pores and the slow increasing section represents the throat;

[0032] A first projection module is used to project the fast increasing section and the slow increasing section onto the coordinate axis where the pore throat diameter is located, to obtain the diameter range of each section of the pore and throat;

[0033] A second projection module is used to project the fast increasing section and the slow increasing section onto the coordinate axis where the cumulative mercury saturation is located, and calculate the mercury saturation corresponding to each section of the pores and throat; and

[0034] The calculation module is used to calculate the volume ratio of pores and throats in different pore throat diameter ranges based on the mercury saturation corresponding to each section of pores and throats.

[0035] In one embodiment, the drawing module includes a capillary pressure module; the capillary pressure module is used to calculate the pore throat diameter corresponding to each of the mercury injection pressures using a capillary pressure formula, wherein the capillary pressure formula is as shown in Formula 1:

[0036] Pc=2σcos(θ) / r Formula 1

[0037] Where Pc is the capillary pressure; σ is the interfacial tension; θ is the wettability contact angle; and r is the pore throat radius.

[0038] According to one aspect of the present application, an embodiment provides an electronic device, including:

[0039] Memory; and

[0040] processor;

[0041] Wherein, the memory is used to store one or more computer instructions; the one or more computer instructions are executed by the processor to implement the tight reservoir pore throat ratio evaluation method as described in any one of the above.

[0042] According to one aspect of the present application, an embodiment provides a readable storage medium having computer instructions stored thereon; wherein, when the computer instructions are executed by a processor, a method for evaluating the pore-throat ratio of a tight reservoir as described in any one of the above items is implemented.

[0043] The technical solution of the above embodiment of the present application evaluates the pore throat ratio of the tight reservoir based on the high-pressure mercury injection test data. The method and device for evaluating the pore throat ratio of the tight reservoir of the present invention can quickly calculate the pore throat ratio of the tight reservoir based on the commonly used high-pressure mercury injection test data, and has the characteristics of simple operation and low experimental test cost, and can be widely used in the pore structure evaluation of the tight reservoir. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 is a flow chart of a method for evaluating pore-throat ratio of a tight reservoir in an embodiment;

[0045] Figure 2 is a schematic structural diagram of a device for evaluating pore-throat ratio of a tight reservoir in an embodiment;

[0046] Figure 3is a pore throat ratio analysis diagram of a tight reservoir in an embodiment;

[0047] Figure 4 The figure is a relationship curve diagram of the pore throat diameter and the cumulative mercury injection saturation of the tight reservoir in the Zhongyuanba-Bazhong area in an embodiment. DETAILED DESCRIPTION

[0048] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0049] In order to enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only embodiments of a part of the present application, not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work should fall within the scope of protection of the present application.

[0050] It should be noted that the terms "first", "second" etc. in the present application are used to distinguish similar objects, and need not be used to describe a specific order or sequential order. It should be understood that the data used in this way can be interchanged in appropriate circumstances, so that the embodiments of the present application described here. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, the process, method, system, product or equipment comprising a series of steps or units need not be limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or equipment.

[0051] It should be understood that when an element (such as a layer, film, region, or substrate) is described as being "on" another element, the element may be directly on the other element, or there may be an intermediate element. Moreover, in this application, when an element is described as being "connected" to another element, the element may be "directly connected" to the other element, or "connected" to the other element through a third element.

[0052] Embodiment 1

[0053] Please refer to Figure 1 An embodiment provides a method for evaluating the pore-throat ratio of a tight reservoir, comprising the following steps:

[0054] S1. Carry out high-pressure mercury injection test on rock samples to obtain data on mercury injection pressure, pore throat diameter and mercury saturation. The test standard can refer to the industry standard "Determination of Rock Capillary Pressure Curve" (SY / T5346-2005) issued by my country's Petroleum Industry Standardization Technical Committee.

[0055] In an embodiment of step S1, preferably, the mercury injection pressure ranges from 0.014 MPa to 413 MPa, and the corresponding pore throat diameter ranges from 3 nm to 100 μm.

[0056] S2. Calculate the pore throat diameter corresponding to each mercury injection pressure, and draw a relationship curve between pore throat diameter and cumulative mercury injection saturation on a coordinate system, wherein different pore throat diameters correspond to different cumulative mercury injection saturations.

[0057] In step S2, the calculation of the pore throat diameter is specifically as follows: referring to the interfacial tension and wetting angle of the rock sample, and using the capillary pressure formula to calculate the pore throat diameter corresponding to each of the mercury injection pressures, wherein the capillary pressure formula is as shown in Formula 1:

[0058] Pc=2σcos(θ) / r Formula 1

[0059] Where Pc is the capillary pressure; σ is the interfacial tension; θ is the wettability contact angle; and r is the pore throat radius.

[0060] In one embodiment of step S2, when drawing the relationship curve between pore throat diameter and cumulative mercury injection saturation, the pore throat diameter is used as the abscissa and the cumulative mercury injection saturation corresponding to different pore throat diameters is used as the ordinate. The abscissa and ordinate form a coordinate system.

[0061] S3. The mercury saturation is divided into a fast increasing section and a slow increasing section according to the degree of change of the relationship curve, wherein the fast increasing section represents the pores and the slow increasing section represents the throat. Specifically, the mercury saturation can be divided into a fast increasing section and a slow increasing section according to the degree of steep change of the relationship curve.

[0062] In an embodiment of step S3, starting from the end of the larger pore throat diameter, the cumulative mercury injection saturation is divided into a fast increasing section and a slow increasing section in sequence.

[0063] S4. Project the fast increasing section and the slow increasing section onto the coordinate axis where the pore throat diameter is located to obtain the diameter range of each section of the pore and throat. If the pore throat diameter is the horizontal axis, project the fast increasing section and the slow increasing section onto the horizontal axis.

[0064] S5. Project the fast increasing section and the slow increasing section onto the coordinate axis where the cumulative mercury injection saturation is located, and calculate the mercury saturation corresponding to each section of the pores and throat. If the cumulative mercury injection saturation is the ordinate, project the fast increasing section and the slow increasing section onto the ordinate.

[0065] S6. Based on the mercury saturation corresponding to each section of pores and throats, the volume ratio of pores and throats in different pore throat diameter ranges is calculated. Among them, based on the relationship curve between pore throat diameter and cumulative mercury saturation, the mercury saturation on each section of pores and throats (i.e., the increment of mercury saturation, obtained by subtracting the cumulative mercury saturation) is the volume of the corresponding pores and throats. According to the volume, the volume ratio of each section of pores and throats can be further calculated. Among them, the ratio of the volume of each section of pores and throats to the total volume of all pores and throats is the volume ratio of the section of pores and throats.

[0066] The method for evaluating the pore-throat ratio of a tight reservoir of the present invention generally comprises the following steps: high-pressure mercury injection test of a rock sample, drawing a relationship curve between pore-throat diameter and cumulative mercury injection saturation, identifying pores and throats, and calculating their ratios. The method of the present invention can quickly calculate the pore-throat ratio of a tight reservoir based on commonly used high-pressure mercury injection test data, has the characteristics of simple operation, low experimental test cost, etc., and can be widely used in the evaluation of the pore structure of a tight reservoir.

[0067] Embodiment 2

[0068] Current casting thin sections, scanning electron microscopy, CT imaging, nuclear magnetic resonance, high-pressure mercury injection conventional analysis and other technologies cannot obtain the ratio relationship between effective pores and throats in tight reservoirs, while micro-nano CT and constant rate mercury injection technology can distinguish pores and throats, but there are problems such as high experimental testing costs and long testing cycles. To address these problems, the present invention proposes a method for evaluating the pore-throat ratio of tight reservoirs based on high-pressure mercury injection technology.

[0069] Please refer to Figure 1 An embodiment provides a method for evaluating the pore-throat ratio of a tight reservoir, including the following processes: high-pressure mercury injection testing of rock samples, drawing of a relationship curve between pore-throat diameter and cumulative mercury saturation, identification of pores and throats, and calculation of their ratios.

[0070] In detail, the evaluation method of pore-throat ratio of tight reservoir is firstly to carry out conventional high-pressure mercury injection test experiment on rock samples; then, the mercury injection pressure (mercury injection pressure) in the experimental data is converted into the corresponding pore throat diameter, and the relationship curve of pore throat diameter-cumulative mercury injection saturation is drawn with pore throat diameter as the horizontal coordinate and cumulative mercury injection saturation as the vertical coordinate; further, according to the change of the relationship curve, the rapid increase section and slow increase section of mercury injection saturation are divided into the rapid increase section and slow increase section to represent pores and throats respectively; then, the pore section and throat section on the relationship curve are projected onto the coordinate axis of pore throat diameter respectively, and the diameter range of each section of pores and throats is obtained; finally, the pore section and throat section obtained from the relationship curve are projected onto the coordinate axis of mercury injection saturation respectively, and the mercury saturation corresponding to each section is calculated, and then through calculation and analysis, the volume ratio of pores and throats in different diameter ranges can be obtained.

[0071] Embodiment 3

[0072] Please refer to Figure 1 , Figure 3 An embodiment provides a method for evaluating the pore-throat ratio of a tight reservoir. The following will describe the technical solution of the present invention with the thoughts of the inventor, which will help those skilled in the art to be familiar with the idea of ​​the present invention. Among them, some technical points are explained in detail, so that those skilled in the art can fully understand the technical solution of the present invention.

[0073] The method for evaluating the pore-throat ratio of a tight reservoir comprises the following steps:

[0074] (1) High-pressure mercury injection test of rock samples

[0075] The AutoPore IV9500 mercury intrusion instrument was used to test rock samples in tight reservoirs. The test standard refers to the industry standard "Determination of Rock Capillary Pressure Curve" (SY / T5346-2005) issued by the Technical Committee of Standardization of Petroleum Industry of my country. Through the test, the mercury injection pressure, pore throat diameter and mercury saturation data with a mercury injection pressure range of 0.014MPa to 413MPa (corresponding to a pore throat size range of 3nm to 100μm) were obtained.

[0076] (2) Plotting the relationship curve between pore throat diameter and cumulative mercury saturation

[0077] Referring to the interfacial tension and wetting angle of the rock sample, the pore throat diameter corresponding to each mercury injection pressure (mercury injection pressure) was calculated using the classic capillary pressure formula (Formula 1). Then, the relationship curve between pore throat diameter and cumulative mercury injection saturation was plotted, with the pore throat diameter as the abscissa and the cumulative mercury injection saturation corresponding to different pore throat diameters as the ordinate.

[0078] Pc=2σcos(θ) / r (Formula 1)

[0079] Where Pc is the capillary pressure; σ is the interfacial tension; θ is the wettability contact angle; and r is the pore throat radius.

[0080] (3) Identification of pores and throats

[0081] According to the steep change of the relationship curve between pore throat diameter and cumulative mercury saturation, starting from the end with large pore throat diameter, the mercury saturation is divided into a rapid increase section and a slow increase section in sequence, which represent the pores and throats respectively. Then, the pore section (corresponding to the void) and the throat section (corresponding to the throat) on the relationship curve are projected onto the coordinate axis of the pore throat diameter to obtain the diameter range of each section of the pores and throats.

[0082] (4) Calculation of volume ratio of pores and throats

[0083] The pore sections and throat sections obtained on the relationship curve of pore throat diameter-cumulative mercury saturation are projected onto the coordinate axis of mercury saturation, and the mercury saturation corresponding to each section is calculated. After calculation and analysis, the volume proportion of pores and throats in different diameter ranges is obtained.

[0084] in, Figure 3 This is a pore-throat ratio analysis diagram for tight reservoirs. In the figure, pore 1, throat 2, pore 3, throat 4, pore 5, and throat 6 are the distribution of pores and throats divided in sequence according to the rapid increase section and slow increase section of the pore throat diameter-cumulative mercury saturation curve, and correspond to different pore throat diameter ranges. Volume 1, volume 2, volume 3, volume 4, volume 5, and volume 6 are the mercury saturations corresponding to the rapid increase section and the slow increase section, which correspond to pore 1, throat 2, pore 3, throat 4, pore 5, and throat 6 respectively; according to the above mercury saturation, the volume ratio of pores and throats in different diameter ranges can be obtained.

[0085] The present invention evaluates the pore throat ratio of a tight reservoir based on high-pressure mercury injection experimental data, can quickly calculate the pore throat ratio of a tight reservoir, has the characteristics of simple operation, low experimental test cost, etc., and can be widely used in the pore structure evaluation of a tight reservoir.

[0086] Embodiment 4

[0087] Please refer to Figure 1 , Figure 4 An embodiment provides a method for evaluating the pore-throat ratio of a tight reservoir, which is described below through a case to facilitate further understanding of the technical solution.

[0088] Taking the Xujiahe Formation tight sandstone reservoir in the Yuanba-Bazhong area of ​​the Sichuan Basin as an example, the pore throat ratio evaluation method of the tight reservoir contains the following steps:

[0089] (1) High-pressure mercury injection test of rock samples

[0090] The core samples of six tight reservoirs were tested using the AutoPore IV9500 high pressure gauge. The test standard was based on the industry standard "Determination of Rock Capillary Pressure Curve" (SY / T5346-2005) issued by the my country Petroleum Industry Standardization Technical Committee. Through the test, the mercury injection pressure, pore throat diameter, and mercury saturation data were obtained in the range of 0.014MPa-413MPa (corresponding to the pore throat size range of 3nm-100μm).

[0091] (2) Plotting the relationship curve between pore throat diameter and cumulative mercury saturation

[0092] Through the analysis of interfacial tension and wetting angle, the interfacial tension of the experimental sample was obtained to be 485 mN / m and the wetting angle was 130°. The pore throat diameter corresponding to each mercury injection pressure (mercury injection pressure) was calculated using the classic capillary pressure formula (see Formula 1 in the above embodiment); then, the relationship curve between pore throat diameter and cumulative mercury injection saturation was plotted with the pore throat diameter as the abscissa and the cumulative mercury injection saturation corresponding to each pore throat diameter as the ordinate, as shown in FIG. Figure 4 shown.

[0093] (3) Identification of pores and throats

[0094] According to the steep change of the relationship curve between pore throat diameter and cumulative mercury saturation, starting from the end of the large pore throat diameter, the mercury saturation is divided into a rapid increase section and a slow increase section in sequence. The rapid increase section and the slow increase section represent the pores and throats, respectively. Then, the pore section and throat section on the curve are projected onto the coordinate axis of the pore throat diameter, respectively, to obtain the diameter range of each section of the pores and throats, as shown in Table 1.

[0095] (4) Calculation of volume ratio of pores and throats

[0096] The pore segments and throat segments obtained on the relationship curve of pore throat diameter-cumulative mercury saturation are projected onto the coordinate axis of cumulative mercury saturation, and the mercury saturation corresponding to each segment is calculated. The volume proportions of pores and throats in different diameter ranges are obtained by calculation, as shown in Table 2.

[0097] Table 1 Distribution range of pore throat diameters in tight reservoirs in Yuanba-Bazhong area

[0098]

[0099] Table 2 Distribution of pore throat ratios in tight reservoirs in Yuanba-Bazhong area

[0100]

[0101] Embodiment 5

[0102] Please refer to Figure 2 , an embodiment provides a tight reservoir pore-throat ratio evaluation device, which has the following structural form.

[0103] (1) Experimental module 10 is used to carry out high-pressure mercury injection testing experiments on rock samples to obtain data on mercury injection pressure, pore throat diameter and mercury injection saturation.

[0104] (2) The drawing module 20 is used to calculate the pore throat diameter corresponding to each mercury injection pressure, and draw a relationship curve between the pore throat diameter and the cumulative mercury injection saturation on a coordinate system, wherein different pore throat diameters correspond to different cumulative mercury injection saturations.

[0105] (3) The division module 30 is used to divide the mercury saturation into a fast increasing section and a slow increasing section according to the degree of change of the relationship curve, wherein the fast increasing section represents the pores and the slow increasing section represents the throat.

[0106] (4) The first projection module 40 is used to project the fast increasing section and the slow increasing section onto the coordinate axis where the pore throat diameter is located, respectively, to obtain the diameter range of each section of the pore and throat.

[0107] (5) The second projection module 50 is used to project the fast increasing section and the slow increasing section onto the coordinate axis where the cumulative mercury saturation is located, and calculate the mercury saturation corresponding to each section of the pores and throat.

[0108] (6) The calculation module 60 is used to calculate the volume ratio of pores and throats in different pore throat diameter ranges based on the mercury saturation corresponding to each section of pores and throats.

[0109] In one embodiment, the drawing module 20 includes a capillary pressure module; the capillary pressure module is used to calculate the pore throat diameter corresponding to each of the mercury injection pressures, specifically including the following steps: referring to the interfacial tension and wetting angle of the rock sample, and using the capillary pressure formula to calculate the pore throat diameter corresponding to each of the mercury injection pressures, wherein the capillary pressure formula is as shown in Formula 1:

[0110] Pc=2σcos(θ) / r Formula 1

[0111] Where Pc is the capillary pressure; σ is the interfacial tension; θ is the wettability contact angle; and r is the pore throat radius.

[0112] It should be noted that the above-mentioned tight reservoir pore-throat ratio evaluation device is used to implement the tight reservoir pore-throat ratio evaluation method in the above-mentioned embodiments, and each module in the device corresponds to each step in the method.

[0113] Embodiment 6

[0114] Based on the same inventive concept, an embodiment of the present application provides an electronic device, comprising: a memory and a processor; wherein the memory is used to store one or more computer instructions; the one or more computer instructions are executed by the processor to perform the tight reservoir pore throat ratio evaluation method described in any one of the above embodiments.

[0115] Embodiment 7

[0116] Based on the same inventive concept, an embodiment of the present application provides a readable storage medium, on which computer instructions are stored; wherein, when the computer instructions are executed by a processor, the method for evaluating the pore throat ratio of a tight reservoir described in any one of the above embodiments is implemented.

[0117] Among them, the above one or more computer instructions can be formed into a program.

[0118] The above program can be run in the processor, or it can be stored in the memory (or computer-readable medium), which includes permanent and non-permanent, removable and non-removable media. Information storage can be achieved by any method or technology. Information can be computer-readable instructions, data structures, program modules or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technology, read-only compact disk read-only memory (CD-ROM), digital versatile disk (DVD) or other optical storage, magnetic cassettes, tape disk storage or other magnetic storage devices or any other non-transmission media that can be used to store information that can be accessed by a computing device. As defined in this article, computer-readable media does not include temporary computer-readable media (transitory media), such as modulated data signals and carrier waves.

[0119] These computer programs can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, so that the instructions executed on the computer or other programmable device provide instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps of the functions specified in one or more blocks can be implemented by different modules corresponding to different steps.

[0120] The above description is only the preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A method for evaluating pore-throat ratio of tight reservoirs, characterized in that: include: Conduct high-pressure mercury injection tests on rock samples to obtain data on mercury injection pressure, pore throat diameter, and mercury injection saturation; Calculating the pore throat diameter corresponding to each of the mercury injection pressures, and drawing a relationship curve between the pore throat diameter and the cumulative mercury injection saturation on a coordinate system, wherein different pore throat diameters correspond to different cumulative mercury injection saturations; According to the degree of change of the relationship curve, the mercury saturation is divided into a fast increasing section and a slow increasing section, wherein the fast increasing section represents the pores and the slow increasing section represents the throat; The fast increasing section and the slow increasing section are projected onto the coordinate axis where the pore throat diameter is located, respectively, to obtain the diameter range of each section of the pore and throat; The fast increasing section and the slow increasing section are projected onto the coordinate axis where the cumulative mercury intrusion saturation is located, respectively, and the mercury saturation corresponding to each section of the pores and throat is calculated; Based on the mercury saturation corresponding to each section of pores and throats, the volume ratios of pores and throats in different pore throat diameter ranges are calculated.

2. A method for evaluating pore-throat ratio of a tight reservoir according to claim 1, characterized in that: In the high-pressure mercury injection test experiment, the mercury injection pressure ranges from 0.014 MPa to 413 MPa, and the corresponding pore throat diameter ranges from 3 nm to 100 μm.

3. The method for evaluating the pore-throat ratio of a tight reservoir according to claim 1, characterized in that: The calculating of the pore throat diameters corresponding to the mercury injection pressures comprises: Referring to the interfacial tension and wetting angle of the rock sample, the pore throat diameter corresponding to each mercury injection pressure is calculated using the capillary pressure formula, wherein the capillary pressure formula is as shown in Formula 1: Pc=2σcos(θ) / r Formula 1 Where Pc is the capillary pressure; σ is the interfacial tension; θ is the wettability contact angle; and r is the pore throat radius.

4. A method for evaluating pore-throat ratio of a tight reservoir according to claim 1, characterized in that: In the coordinate system, the pore throat diameter is set as the abscissa, and the cumulative mercury injection saturation is set as the ordinate.

5. The method for evaluating pore-throat ratio of a tight reservoir according to claim 1, characterized in that: According to the degree of steep change of the relationship curve, starting from the end of the larger pore throat diameter, the cumulative mercury injection saturation is divided into a fast increasing section and a slow increasing section.

6. A method for evaluating pore-throat ratio of a tight reservoir according to claim 1, characterized in that: The volume of each section of the pores and the throat is the mercury saturation corresponding to the pores and the throat.

7. A device for evaluating pore-throat ratio of a tight reservoir, characterized in that: include: The experimental module is used to conduct high-pressure mercury injection tests on rock samples to obtain data on mercury injection pressure, pore throat diameter, and mercury injection saturation; A drawing module, used for calculating the pore throat diameter corresponding to each mercury injection pressure, and drawing a relationship curve between the pore throat diameter and the cumulative mercury injection saturation on a coordinate system, wherein different pore throat diameters correspond to different cumulative mercury injection saturations; A division module, used for dividing the mercury saturation into a fast increasing section and a slow increasing section according to the degree of change of the relationship curve, wherein the fast increasing section represents the pores and the slow increasing section represents the throat; A first projection module is used to project the fast increasing section and the slow increasing section onto the coordinate axis where the pore throat diameter is located, to obtain the diameter range of each section of the pore and throat; A second projection module is used to project the fast increasing section and the slow increasing section onto the coordinate axis where the cumulative mercury saturation is located, and calculate the mercury saturation corresponding to each section of the pores and throat; and The calculation module is used to calculate the volume ratio of pores and throats in different pore throat diameter ranges based on the mercury saturation corresponding to each section of pores and throats.

8. A device for evaluating pore-throat ratio of a tight reservoir according to claim 7, characterized in that: The drawing module includes a capillary pressure module; the capillary pressure module is used to calculate the pore throat diameter corresponding to each of the mercury injection pressures using a capillary pressure formula, wherein the capillary pressure formula is as follows: Pc=2σcos(θ) / r Formula 1 Where Pc is the capillary pressure; σ is the interfacial tension; θ is the wettability contact angle; and r is the pore throat radius.

9. An electronic device, characterized in that: include: Memory; and processor; Wherein, the memory is used to store one or more computer instructions; the one or more computer instructions are executed by the processor to implement the method for evaluating the pore-throat ratio of a tight reservoir as described in any one of claims 1 to 6.

10. A readable storage medium, characterized in that: The readable storage medium stores computer instructions; wherein, when the computer instructions are executed by a processor, the method for evaluating the pore-throat ratio of a tight reservoir as described in any one of claims 1 to 6 is implemented.

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