Rock appearance volume detection method and rock porosity detection method

Abstract

The invention relates to the field of oil and gas exploration and development, and discloses a rock appearance volume detection method and a rock porosity detection method.The rock appearance volume detection method comprises the steps that a to-be-detected rock sample is immersed in molten paraffin liquid, and a paraffin-sealed rock sample is obtained; based on the mass of the to-be-measured rock sample, the mass of the paraffin-sealed rock sample and the paraffin density, determining the volume of the paraffin wrapped on the outer surface of the paraffin-sealed rock sample; placing the paraffin-sealed rock sample in a helium hole instrument for detection to obtain the appearance volume of the paraffin-sealed rock sample; and determining the appearance volume of the rock sample to be measured according to the volume of the paraffin wrapped on the outer surface of the paraffin-sealed rock sample and the appearance volume of the paraffin-sealed rock sample. Based on the scheme provided by the embodiment of the invention, the appearance volume of the rock sample to be measured can be accurately determined, so that the accurate porosity of the rock sample can be obtained.

Description

Technical Field

[0001] This invention relates to the field of oil and gas exploration and development technology, specifically to a method for detecting the volume of rock appearance and a method for detecting rock porosity. Background Technology

[0002] Porosity, also known as total porosity, is the ratio of the volume of pores in a rock to its apparent volume. It characterizes the proportion of pores in a unit volume of rock and is a key parameter for evaluating oil and gas reserves in oil and gas exploration and development.

[0003] Porosity testing comprises two parts: pore volume testing and apparent volume testing. Currently, methods for pore volume testing mainly include gas methods, saturated liquid methods, nuclear magnetic resonance (NMR), true apparent density methods, and mercury porosimetry combined with gas adsorption methods; among these, gas methods are the most widely used. Gas methods typically use helium and measure the skeletal volume of rocks based on Bohr's law. Methods for apparent volume testing mainly include measurement methods, mercury pump methods, and wax sealing methods. For regularly shaped rock samples, measurement methods are typically used to determine their external dimensions and then calculate their apparent volume. However, in practical applications, for loose and brittle rock samples or dense shale and other rock samples with extremely low porosity, the appearance is often irregular. For these irregularly shaped rock samples, the wax sealing method is typically used to test their apparent volume. The specific process involves melting paraffin wax at a certain temperature, then immersing the rock sample to be tested in the wax liquid, ensuring the outer surface of the rock sample is uniformly coated with the wax liquid. Then, based on the mass of the unsealed rock sample, the mass of the sealed rock sample, the paraffin density, and the mass of the sealed rock sample in the density balance, the apparent volume and density of the rock sample are calculated, wherein the paraffin density is detected by the density balance.

[0004] However, during the process of detecting the apparent volume of rock samples, when the sealed rock sample is placed on a density balance for testing, the surface tension of the liquid and the air bubbles on the surface of the rock sample will affect the accuracy of the density test, which will lead to inaccurate detection of the apparent volume of the rock sample, and thus inaccurate detection of the porosity of the rock sample. Summary of the Invention

[0005] The purpose of this invention is to overcome the problem in the prior art that the inaccuracy of rock sample porosity detection is due to the inaccuracy of rock sample appearance volume detection, and to provide a method for rock appearance volume detection and a method for rock porosity detection.

[0006] To achieve the above objectives, a first aspect of the present invention provides a method for detecting the volume of rock appearance, comprising:

[0007] The rock sample to be tested is immersed in molten paraffin liquid to obtain a sealed rock sample;

[0008] Based on the mass of the rock sample to be tested, the mass of the rock sample after sealing with wax, and the density of paraffin wax, determine the volume of paraffin wax covering the outer surface of the rock sample after sealing with wax;

[0009] The wax-sealed rock sample was placed in a helium porosimeter for testing to obtain the apparent volume of the wax-sealed rock sample.

[0010] The apparent volume of the rock sample to be tested is determined based on the volume of paraffin wax covering the outer surface of the sealed rock sample and the apparent volume of the sealed rock sample.

[0011] In this embodiment of the application, immersing the rock sample to be tested in molten paraffin liquid includes:

[0012] The rock sample to be tested is completely immersed in molten paraffin liquid so that all the outer surfaces of the rock sample are coated with paraffin.

[0013] In this embodiment of the application, after all the outer surfaces of the rock sample to be tested are coated with paraffin wax, a rock sample to be tested with all the outer surfaces coated with solidified paraffin wax is obtained. The rock sample to be tested with all the outer surfaces coated with solidified paraffin wax is used as the rock sample after wax sealing.

[0014] In this embodiment, the volume of paraffin wax coating the outer surface of the sealed rock sample is determined based on the following formula:

[0015]

[0016] Where V1 is the volume of paraffin wax covering the outer surface of the rock sample after sealing, in cm³. 3 m1 is the mass of the rock sample to be tested, in g; m2 is the mass of the rock sample after sealing with paraffin, in g; ρ is the density of paraffin wax, in g / cm³. 3 .

[0017] In this embodiment of the application, the density of the paraffin wax is the density of solidified paraffin wax.

[0018] In this embodiment of the application, the paraffin density is obtained through the following process:

[0019] The solidified paraffin block corresponding to the liquid paraffin is weighed to obtain the mass of the solidified paraffin block;

[0020] The solidified paraffin block was placed in a helium porosimeter for testing to obtain the apparent volume of the solidified paraffin block;

[0021] Based on the mass and apparent volume of the solidified paraffin wax block, the density of the solidified paraffin wax block is determined, and the density of the solidified paraffin wax block is taken as the density of the paraffin wax.

[0022] In this embodiment, the apparent volume of the rock sample to be tested is determined based on the following formula:

[0023] V3 = V2 - V1;

[0024] Where V3 is the external volume of the rock sample to be tested, in cm³. 3 V2 represents the apparent volume of the rock sample after wax sealing, in cm³. 3 V1 represents the volume of paraffin wax covering the outer surface of the rock sample after sealing, in cm³. 3 .

[0025] A second aspect of the present invention provides a method for detecting rock porosity, comprising determining the porosity of the rock sample based on the skeleton volume of the rock sample to be tested and the apparent volume of the rock sample to be tested obtained by the rock apparent volume detection method provided in the first aspect.

[0026] In this embodiment of the application, the rock sample to be tested is placed in a helium porosimeter for detection to obtain the skeleton volume of the rock sample.

[0027] In this embodiment, the porosity of the rock sample to be tested is determined based on the following formula:

[0028]

[0029] Where φ is the porosity of the rock sample to be tested; V3 is the external volume of the rock sample to be tested, in cm³. 3 V4 represents the skeletal volume of the rock sample to be tested, in cm³. 3 .

[0030] The above technical solution includes: immersing a rock sample to be tested in molten paraffin wax to obtain a wax-sealed rock sample; determining the volume of paraffin wax covering the outer surface of the wax-sealed rock sample based on the mass of the rock sample to be tested, the mass of the wax-sealed rock sample, and the density of paraffin wax; placing the wax-sealed rock sample in a helium porosimeter for testing to obtain the apparent volume of the wax-sealed rock sample; and determining the apparent volume of the rock sample to be tested based on the volume of paraffin wax covering the outer surface of the wax-sealed rock sample and the apparent volume of the wax-sealed rock sample. Based on the rock apparent volume detection method provided in this application, the apparent volume of the rock sample to be tested can be accurately determined; furthermore, the accurate porosity of the rock sample can be obtained.

[0031] Other features and advantages of the embodiments of this application will be described in detail in the following detailed description section. Attached Figure Description

[0032] The accompanying drawings are provided to further illustrate the embodiments of this application and form part of the specification. They are used together with the following detailed description to explain the embodiments of this application, but do not constitute a limitation on the embodiments of this application. In the drawings:

[0033] Figure 1 The schematic diagram illustrates a flow chart of a rock appearance volume detection method according to an embodiment of this application;

[0034] Figure 2 The schematic diagram illustrates the structure of a helium aperture detector-related testing device according to an embodiment of this application.

[0035] Explanation of reference numerals in the attached figures

[0036] 201—Helium gas tank; 202—Reference cell; 203—Sample cell. Detailed Implementation

[0037] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only for illustration and explanation of the embodiments of this application and are not intended to limit the embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0038] If the embodiments of this application involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. If the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed in this application.

[0039] As described in the background section, porosity is a key parameter for evaluating oil and gas reserves in oil and gas exploration and development. Porosity testing includes two parts: pore volume testing and apparent volume testing. Currently, methods for pore volume testing mainly include gas methods, saturated liquid methods, nuclear magnetic resonance methods, true apparent density methods, and mercury intrusion porosimetry combined with gas adsorption methods; among these, gas methods are the most widely used. Gas methods typically use helium and measure the skeletal volume of rocks based on Bohr's law. Methods for apparent volume testing mainly include measurement methods, mercury pump methods, and wax sealing methods. For regularly shaped rock samples, measurement methods are usually used to measure their external dimensions and then calculate their apparent volume. However, in practical applications, for loose and brittle rock samples or dense shale and other rock samples with extremely low porosity, the appearance often presents an irregular shape. For these irregularly shaped rock samples, the wax sealing method is usually used to test their apparent volume. The specific process is as follows: paraffin wax is melted at a certain temperature, and then the rock sample to be tested is immersed in the wax liquid, so that the outer surface of the rock sample is uniformly coated with the wax liquid. Then, based on the mass of the unsealed rock sample, the mass of the sealed rock sample, the paraffin density, and the mass of the sealed rock sample in a density balance, the apparent volume and density of the rock sample were calculated. The paraffin density was determined using a density balance. However, during the process of determining the apparent volume of the rock sample, when the sealed rock sample was placed on the density balance, the surface tension of the liquid and air bubbles on the rock sample surface affected the accuracy of the density measurement, leading to inaccurate apparent volume determination and consequently, inaccurate porosity determination.

[0040] To address this, one embodiment of this application provides a method for detecting the volume of rock appearance, such as... Figure 1 As shown, the detection method may include the following steps:

[0041] Step 101: Immerse the rock sample to be tested in molten paraffin liquid to obtain a sealed rock sample.

[0042] The rock sample to be tested can be any rock sample with a regular or irregular shape. It is understood that the solution provided in this application embodiment can also be applied to detect the appearance and volume of other non-rock samples, such as coal.

[0043] In this embodiment of the application, immersing the rock sample to be tested in molten paraffin liquid may include: completely immersing the rock sample to be tested in molten paraffin liquid so that all outer surfaces of the rock sample to be tested are coated with paraffin.

[0044] More specifically, after all the outer surfaces of the rock sample to be tested are coated with paraffin wax, a rock sample to be tested with all the outer surfaces coated with solidified paraffin wax is obtained. The rock sample to be tested with all the outer surfaces coated with solidified paraffin wax is used as the rock sample after wax sealing.

[0045] That is, the rock sample to be tested is completely immersed in the molten paraffin liquid. After the paraffin liquid fully coats the outer surface of the rock sample, the rock sample is removed from the paraffin liquid. After the paraffin liquid coating the outer surface of the rock sample solidifies, the sealed rock sample is obtained.

[0046] Step 102: Based on the mass of the rock sample to be tested, the mass of the rock sample after sealing with wax, and the density of paraffin wax, determine the volume of paraffin wax covering the outer surface of the rock sample after sealing with wax.

[0047] The mass of the rock sample to be tested is the mass of the rock sample before it is sealed with wax. In practical applications, the mass of the rock sample to be tested and the mass of the rock sample after sealing with wax can be obtained using a weighing balance.

[0048] In step 102, the paraffin density used to determine the volume of paraffin wax covering the outer surface of the rock sample after sealing is the density of solidified paraffin wax. In this embodiment, the paraffin density can be obtained through the following process:

[0049] The solidified paraffin block corresponding to the liquid paraffin is weighed to obtain the mass of the solidified paraffin block; the solidified paraffin block is placed in a helium pore sizer for testing to obtain the apparent volume of the solidified paraffin block; based on the mass and apparent volume of the solidified paraffin block, the density of the solidified paraffin block is determined, and the density of the solidified paraffin block is taken as the paraffin density.

[0050] The solidified paraffin block corresponding to the paraffin liquid can be obtained by taking a portion of the solidified paraffin as the solidified paraffin block before it melts, and melting the remaining solidified paraffin to obtain the paraffin liquid used to soak the rock sample to be tested.

[0051] When the solidified paraffin block is placed in a helium atomometer for testing, the helium atomometer can detect the appearance and volume of the solidified paraffin block based on Bohr's law.

[0052] Specifically, the helium aperture detector and related testing equipment can be as follows: Figure 2As shown, the testing equipment includes a helium tank 201, a reference cell 202, a sample cell 203, several valves F, and several pressure sensors M; the helium tank 201, reference cell 202, and sample cell 203 are connected sequentially; valves F and pressure sensors M are installed on the pipeline connecting the helium tank 201 and the reference cell 202, valve F is installed on the pipeline connecting the reference cell 202 and the sample cell 203, and valve F is installed on the vent pipeline of the sample cell 203; pressure sensors M are installed on both the reference cell 202 and the sample cell 203. The process of using this testing equipment to detect the appearance and volume of solidified paraffin blocks can be as follows:

[0053] Step 1: Place the solidified paraffin block into the sample cell of the helium pore apparatus. The maximum length of the solidified paraffin block in any direction should not exceed the inner diameter of the sample cell, ensuring that the solidified paraffin block can be placed into the sample cell.

[0054] Step 2: Close the valve between the reference cell and the sample cell, open the valve between the helium tank and the reference cell, and fill the reference cell with helium gas at approximately 200 psi; then, close the valve between the helium tank and the reference cell.

[0055] Step 3: After the pressure in the reference cell stabilizes, record the pressure value, and open the valve between the reference cell and the sample cell. Helium gas flows from the reference cell to the sample cell. After a certain period of time, the pressure stabilizes, and the pressure value is recorded.

[0056] Step 4: Calculate the apparent volume of the solidified paraffin block based on the gas state equation, the pressure values ​​recorded twice, and the volumes of the reference cell and sample cell.

[0057] Furthermore, the density of the solidified paraffin block can be determined based on the following formula (1):

[0058]

[0059] Where ρ is the density of paraffin wax, in g / cm³. 3 m0 is the mass of the solidified paraffin wax block in grams; V0 is the apparent volume of the solidified paraffin wax block in centimeters. 3 .

[0060] In this embodiment of the application, after obtaining the mass of the rock sample to be tested, the mass of the rock sample after sealing with wax, and the density of paraffin wax, the volume of paraffin wax covering the outer surface of the rock sample after sealing with wax can be determined based on the following formula (2):

[0061]

[0062] Where V1 is the volume of paraffin wax covering the outer surface of the rock sample after sealing, in cm³. 3m1 is the mass of the rock sample to be tested, in g; m2 is the mass of the rock sample after sealing with paraffin, in g; ρ is the density of paraffin wax, in g / cm³. 3 .

[0063] Step 103: Place the wax-sealed rock sample in a helium porosimeter for testing to obtain the apparent volume of the wax-sealed rock sample.

[0064] When the wax-sealed rock sample is placed in a helium porosimeter for testing, the helium porosimeter can detect the apparent volume of the wax-sealed rock sample based on Bohr's law.

[0065] Specifically, it can be used Figure 2 The testing equipment shown is used to test the appearance volume of the sealed rock sample. The specific testing process can be referred to the aforementioned testing process for the appearance volume of solidified paraffin blocks, and will not be repeated here.

[0066] Step 104: Determine the apparent volume of the rock sample to be tested based on the volume of paraffin wax covering the outer surface of the sealed rock sample and the apparent volume of the sealed rock sample.

[0067] In this embodiment of the application, the apparent volume of the rock sample to be tested can be determined based on the following formula (3):

[0068] V3 = V2 - V1 (3);

[0069] Where V3 is the external volume of the rock sample to be tested, in cm³. 3 V2 represents the apparent volume of the rock sample after wax sealing, in cm³. 3 V1 represents the volume of paraffin wax covering the outer surface of the rock sample after sealing, in cm³. 3 .

[0070] It is understood that the rock appearance volume detection method provided in this application includes: immersing a rock sample to be tested in molten paraffin liquid to obtain a wax-sealed rock sample; determining the volume of paraffin coating the outer surface of the wax-sealed rock sample based on the mass of the rock sample to be tested, the mass of the wax-sealed rock sample, and the density of paraffin; placing the wax-sealed rock sample in a helium porosimeter for detection to obtain the appearance volume of the wax-sealed rock sample; and determining the appearance volume of the rock sample to be tested based on the volume of paraffin coating the outer surface of the wax-sealed rock sample and the appearance volume of the wax-sealed rock sample. Based on the rock appearance volume detection method provided in this application, the appearance volume of the rock sample to be tested can be accurately determined; consequently, the accurate porosity of the rock sample can be obtained.

[0071] Based on the rock appearance volume detection method provided in the above embodiments of this application, this application also provides a rock porosity detection method, which includes: determining the porosity of the rock sample to be tested based on the skeleton volume of the rock sample to be tested and the appearance volume of the rock sample to be tested obtained by the rock appearance volume detection method provided in the above embodiments.

[0072] The rock sample to be tested can be placed in a helium wellbore apparatus for analysis to obtain its skeletal volume. The helium wellbore apparatus can detect the skeletal volume of the rock sample based on Bomar's law. By using a helium wellbore apparatus to detect the skeletal volume of the rock sample, the same set of equipment can be used to detect both the external volume and the skeletal volume of the rock sample. Furthermore, the same rock sample can be used for both analysis; this simplifies the operation process, reduces experimental costs, and eliminates errors caused by differences in samples.

[0073] Specifically, it can be used Figure 2 The detection equipment shown detects the skeletal volume of the rock sample to be tested. The specific detection process can be referred to the aforementioned detection process of the appearance volume of solidified paraffin blocks, and will not be repeated here.

[0074] In this embodiment of the application, after obtaining the skeleton volume and apparent volume of the rock sample to be tested, the porosity of the rock sample to be tested can be determined based on the following formula (4):

[0075]

[0076] Where φ is the porosity of the rock sample to be tested; V3 is the external volume of the rock sample to be tested, in cm³. 3 V4 represents the skeletal volume of the rock sample to be tested, in cm³. 3 .

[0077] It is understood that the rock porosity detection method provided in this application includes: determining the porosity of the rock sample based on the skeleton volume of the rock sample to be tested and the apparent volume of the rock sample to be tested obtained by the rock apparent volume detection method provided in the above embodiments. Since the apparent volume of the rock sample to be tested can be accurately determined, the accurate porosity of the rock sample can be obtained.

[0078] The following will illustrate the rock appearance volume detection method and rock porosity detection method provided in the embodiments of this application with specific examples. It should be understood that the following examples are only some specific implementation methods and do not imply an improper limitation of the solution of this application.

[0079] Example 1

[0080] Step 1: Weigh the solidified paraffin block to obtain 2.4304g;

[0081] Step two: The solidified paraffin block was placed in a helium porosimeter, and the external volume of the solidified paraffin block was measured to be 2.662 cm³. 3 ;

[0082] Step 3: Calculate the density of the solidified paraffin block according to formula (1), which is 0.913 g / cm³. 3 ;

[0083] Step four: Weigh the sandstone sample to obtain 6.0256g, then place the sandstone sample in a helium porosimeter and measure the skeletal volume to be 2.152cm³. 3 ;

[0084] Step 5: Immerse the sandstone sample in molten paraffin wax to obtain a wax-sealed sandstone sample, which weighs 6.0419g. Calculate the volume of paraffin wax covering the outer surface of the wax-sealed sandstone sample using formula (2) to be 0.01785cm³. 3 ;

[0085] Step six: Place the wax-sealed sandstone sample into a helium porosimeter and measure its external volume as 2.280 cm³. 3 The apparent volume of the sandstone sample, calculated using formula (3), is 2.262 cm³. 3 ;

[0086] Step 7: Calculate the porosity of the sandstone sample as 4.87% according to formula (4).

[0087] Example 2

[0088] Step 1: Weigh the solidified paraffin block to obtain 2.4304g;

[0089] Step two: The solidified paraffin block was placed in a helium porosimeter, and the external volume of the solidified paraffin block was measured to be 2.662 cm³. 3 ;

[0090] Step 3: Calculate the density of the solidified paraffin block according to formula (1), which is 0.913 g / cm³. 3 ;

[0091] Step four: The shale sample was weighed to be 11.086 g, and then the shale sample was placed in a helium porosimeter to measure the skeleton volume as 4.204 cm³. 3 ;

[0092] Step 5: Immerse the shale sample in molten paraffin liquid to obtain a wax-sealed shale sample, which weighs 11.167g. Calculate the volume of paraffin coating the outer surface of the wax-sealed shale sample using formula (2) to be 0.0883cm³. 3 .

[0093] Step six: Place the wax-sealed shale sample into a helium porosimeter and measure its external volume as 4.312 cm³. 3 The apparent volume of the shale sample, calculated according to formula (3), is 4.223 cm³. 3 .

[0094] Step 7: Calculate the porosity of the shale sample according to formula (4), which is 0.453%.

[0095] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0096] The above are merely embodiments of this application and are not intended to limit the scope of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of the claims of this application.

Claims

1. A method for detecting the volume of rock appearance, characterized in that, include: The rock sample to be tested is immersed in molten paraffin liquid to obtain a sealed rock sample; Based on the mass of the rock sample to be tested, the mass of the rock sample after sealing with wax, and the density of paraffin wax, determine the volume of paraffin wax covering the outer surface of the rock sample after sealing with wax; The wax-sealed rock sample was placed in a helium porosimeter for testing to obtain the apparent volume of the wax-sealed rock sample. The apparent volume of the rock sample to be tested is determined based on the volume of paraffin wax covering the outer surface of the sealed rock sample and the apparent volume of the sealed rock sample.

2. The method for detecting the volume of rock appearance according to claim 1, characterized in that, The step of immersing the rock sample to be tested in molten paraffin liquid includes: The rock sample to be tested is completely immersed in molten paraffin liquid so that all the outer surfaces of the rock sample are coated with paraffin.

3. The method for detecting the volume of rock appearance according to claim 2, characterized in that, After all the outer surfaces of the rock sample to be tested are coated with paraffin wax, a rock sample to be tested with all the outer surfaces coated with solidified paraffin wax is obtained. The rock sample to be tested with all the outer surfaces coated with solidified paraffin wax is used as the rock sample after wax sealing.

4. The method for detecting the volume of rock appearance according to claim 1, characterized in that, The volume of paraffin wax coating the outer surface of the sealed rock sample is determined using the following formula: Where V1 is the volume of paraffin wax covering the outer surface of the rock sample after sealing, in cm³. 3 m1 is the mass of the rock sample to be tested, in g; m2 is the mass of the rock sample after sealing with paraffin, in g; ρ is the density of paraffin wax, in g / cm³. 3 .

5. The method for detecting the volume of rock appearance according to claim 4, characterized in that, The density of the paraffin wax is the density of solidified paraffin wax.

6. The method for detecting the volume of rock appearance according to claim 5, characterized in that, The density of the paraffin wax is obtained through the following process: The solidified paraffin block corresponding to the liquid paraffin is weighed to obtain the mass of the solidified paraffin block; The solidified paraffin block was placed in a helium porosimeter for testing to obtain the apparent volume of the solidified paraffin block; Based on the mass and apparent volume of the solidified paraffin wax block, the density of the solidified paraffin wax block is determined, and the density of the solidified paraffin wax block is taken as the density of the paraffin wax.

7. The method for detecting the volume of rock appearance according to claim 1, characterized in that, The apparent volume of the rock sample to be tested is determined based on the following formula: V3 = V2 - V1; Where V3 is the external volume of the rock sample to be tested, in cm³. 3 V2 represents the apparent volume of the rock sample after wax sealing, in cm³. 3 V1 represents the volume of paraffin wax covering the outer surface of the rock sample after sealing, in cm³. 3 .

8. A method for detecting rock porosity, characterized in that, include: The porosity of the rock sample is determined based on the skeleton volume of the rock sample to be tested and the apparent volume of the rock sample to be tested obtained by any one of the rock apparent volume detection methods in claims 1-7.

9. The rock porosity detection method according to claim 8, characterized in that, The rock sample to be tested is placed in a helium porosimeter for detection to obtain the skeletal volume of the rock sample.

10. The method for detecting rock porosity according to claim 8, characterized in that, The porosity of the rock sample to be tested is determined based on the following formula: Where φ is the porosity of the rock sample to be tested; V3 is the external volume of the rock sample to be tested, in cm³. 3 V4 represents the skeletal volume of the rock sample to be tested, in cm³. 3 .

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