Rock sample matrix volume measurement apparatus and method

Abstract

This invention relates to the field of geological technology, and more particularly to a device and method for measuring the skeleton volume of a rock sample. The device for measuring the skeleton volume of a rock sample includes: a first gas path for measuring the volume of a standard rock sample with a known skeleton volume, and a second gas path for measuring the volume of a rock sample to be tested. The first gas path has a first measuring chamber comprising a first cup and a first top cover, which are sealed together by a first sealing ring. The second gas path has a second measuring chamber comprising a second cup and a second top cover, which are sealed together by a second sealing ring. Both the first and second sealing rings are fill-and-discharge type sealing rings, and they are interconnected. This invention, through the design of a dual gas path, achieves automatic identification of the device status during skeleton volume measurement, providing a new means and method for rapidly and accurately measuring rock sample volume and porosity.

Description

Technical Field

[0001] This invention relates to the field of geological technology, and in particular to a device and method for measuring the volume of a rock sample skeleton. Background Technology

[0002] In the process of determining the porosity of rock samples, the gas method is a relatively mature method for determining the volume of the rock sample skeleton. Its principle is: according to Boyle's law, for a given mass of ideal gas, under constant temperature, its pressure is inversely proportional to its volume. A standard chamber and a measuring chamber are connected by a pipeline equipped with a gas pressure sensor (or pressure gauge) and a valve. When a gas (air or nitrogen, etc.) with a certain pressure (initial pressure P1) is introduced into the standard chamber, under isothermal conditions, the gas is transported to the measuring chamber. The gas pressure will gradually decrease until it reaches a stable equilibrium; this pressure is called the equilibrium pressure (P2).

[0003] At this point, the following formula holds true:

[0004] P1*V1=P2*(V2+V1)---------------------------------------------(1)

[0005] Where: V1 is the sum of the volume of the standard chamber and the pipeline from the standard chamber to the valve;

[0006] V2 is the sum of the volume of the measuring chamber and the pipeline from the measuring chamber to the valve;

[0007] When a rock sample with a skeleton volume of V3 is placed in the measuring chamber, the above process is repeated, and the following formula holds true:

[0008] P1*V1=P2*(V2+V1-V3)

[0009] V3=V2+V1-P1*V1 / P2---------------------------------------------(2)

[0010] Therefore, since V2, V1 and P1 are all known, as long as the equilibrium pressure P2 of the gas after the rock sample is loaded is measured, the volume of the rock sample skeleton can be calculated using formula (2). The equilibrium pressure P2 is the key parameter for accurately calculating the volume of the rock sample skeleton.

[0011] The procedure for this determination method is as follows:

[0012] (1) Place the rock sample into the measuring chamber and tighten the top cover of the measuring chamber so that the sealing ring on the top cover of the measuring chamber is compressed and deformed to form a sealed space.

[0013] (2) Open the valve to allow the gas with a certain pressure in the standard chamber to enter the sealed space of the measuring chamber.

[0014] (3) At this time, gas continuously enters the pores of the rock sample, the gas pressure decreases, and under the condition that there is no gas leakage, the pressure tends to stabilize after a period of time and reaches equilibrium. The pressure measured at this time is the equilibrium pressure.

[0015] From the perspective of principle and operation, the advantages of this method are its simple instrument structure and ease of operation. However, it also has certain drawbacks and risks.

[0016] The sealing ring is one of the key components for maintaining the airtightness of the sealed space in the measuring chamber. During the process of gas entering the measuring chamber from the standard chamber and then into the pores of the rock sample, the time required for the pressure to reach stable equilibrium varies greatly depending on the rock sample; some require only a few minutes, while others take tens of minutes. During the gradual pressure decrease, it is difficult for operators to determine whether gas leakage has occurred at the sealing ring or if it is a normal pressure equilibrium process, leading to decreased work efficiency and even affecting the quality of the test.

[0017] Chinese patent (application number 201210273356.3) provides a rock sample volume testing system and a gas leakage monitoring method, which monitors gas leakage in real time during the gas method measurement of rock sample skeleton volume. The system employs the following technical solutions: First, the standard chamber, measurement chamber, and all pipelines and valves involved in the gas sealing are placed in a relatively sealed enclosure. This enclosure can be a relatively sealed chassis with a door on the front for easy insertion and removal of rock samples. Second, a certain amount of tracer gas is mixed into the measuring gas medium. This tracer gas has a low concentration in the atmosphere and is easily detected. Third, a tracer gas detection device is installed inside or outside the enclosure to monitor and display the concentration change of the tracer gas in the enclosure in real time. Fourth, an alarm value for the tracer gas concentration change is set. Once the tracer gas concentration change reaches the lower limit of the alarm value, it indicates gas leakage, the computer will issue an alarm, and the rock sample testing should be stopped. The pipelines should be checked, the leakage location determined, and sealing measures implemented. When the gas pressure drops but the computer does not alarm, it indicates that the gas is slowly entering the tiny pores of the rock sample, and the instrument is functioning normally. You can safely observe the pressure changes until the pressure stabilizes. However, in this method, because a tracer gas is added to the measuring gas, it can affect the calculation results when calculating the skeleton volume using pressure, increasing the measurement error.

[0018] This invention addresses the shortcomings and potential risks of rock sample skeleton volume determination by proposing a new technical solution to ensure testing efficiency and quality. Summary of the Invention

[0019] This invention provides a device and method for measuring the volume of a rock sample skeleton, which addresses at least one of the aforementioned technical problems.

[0020] A first aspect of the present invention provides a rock sample skeleton volume measuring device, comprising: a first gas path for measuring the volume of a standard rock sample with a known skeleton volume, and a second gas path for measuring the volume of a rock sample to be measured.

[0021] The first gas path includes a first measuring chamber for setting the standard rock sample, the first measuring chamber including a first cup body and a first top cover, the first cup body and the first top cover being sealed by a first sealing ring; the second gas path includes a second measuring chamber for setting the rock sample to be tested, the second measuring chamber including a second cup body and a second top cover, the second cup body and the second top cover being sealed by a second sealing ring;

[0022] Both the first sealing ring and the second sealing ring are inflatable sealing rings, and the first sealing ring and the second sealing ring are interconnected.

[0023] In one embodiment, the first sealing ring and the second sealing ring are sealing rings of the same material and specifications;

[0024] The first measuring chamber and the second measuring chamber are air chambers with the same material and specifications.

[0025] In one embodiment, the inflatable sealing ring is an air-filled sealing ring or a liquid-filled sealing ring.

[0026] In one embodiment, a filling device is further included, which is connected to the filling port of the first sealing ring and the filling port of the second sealing ring respectively via a delivery pipeline, and a delivery valve is provided on the delivery pipeline.

[0027] In one embodiment, the first gas path further includes a first standard chamber, the outlet of which is connected to the first measuring chamber via a pipeline, and a first valve is provided on the pipeline between the first standard chamber and the first measuring chamber.

[0028] The second gas path also includes a second standard chamber, the outlet of which is connected to the second measuring chamber via a pipeline, and a second valve is installed on the pipeline between the second standard chamber and the second measuring chamber.

[0029] The first standard chamber and the second standard chamber are air chambers with the same material and specifications. The first standard chamber and the second standard chamber are connected by a pipeline, and a third valve is installed on the pipeline between the first standard chamber and the second standard chamber.

[0030] In one embodiment, the system further includes a gas source for providing the measuring gas, wherein the outlet end of the gas source is provided with a gas source valve, and the gas source valve is connected to the inlet end of the first standard chamber and the inlet end of the second standard chamber respectively through corresponding pipelines.

[0031] In one embodiment, the measuring gas is helium, nitrogen, or air.

[0032] In one embodiment, a detection system is also included, the detection system comprising a control computing system and a first pressure sensor, a second pressure sensor, a third pressure sensor, and a fourth pressure sensor connected to the control computing system.

[0033] The first pressure sensor is connected to the pipeline between the gas source valve and the first standard chamber, the second pressure sensor is connected to the pipeline between the gas source valve and the second standard chamber, the third pressure sensor is connected to the pipeline between the first valve and the first measuring chamber, and the fourth pressure sensor is connected to the pipeline between the second valve and the second measuring chamber.

[0034] A second aspect of the present invention provides a method for measuring the volume of a rock sample skeleton, which uses the above-described rock sample skeleton volume measuring device to measure the volume of a rock sample skeleton, and includes the following steps:

[0035] Step 1: Measure the skeleton volume of the standard rock sample through the first gas path, and simultaneously measure the skeleton volume of the rock sample to be tested through the second gas path.

[0036] Step 2: Compare the measured value and the nominal value of the skeleton volume of the standard rock sample. If the measured value and the nominal value of the skeleton volume of the standard rock sample are within the allowable error range, it is determined that the rock sample skeleton volume measuring device is well sealed and the measured value of the skeleton volume of the rock sample to be tested is accurate and reliable.

[0037] In one implementation, step 1 includes the following sub-steps:

[0038] Step 11: Place the standard rock sample with a known skeleton volume into the first measuring chamber, and place the rock sample with the skeleton volume to be measured into the second measuring chamber;

[0039] Step 12: Simultaneously fill the first sealing ring and the second sealing ring with filling medium through the filling device to seal the first measuring chamber and the second measuring chamber;

[0040] Step 13: Inject the measuring gas at a preset pressure into the first standard chamber and the second standard chamber respectively through the gas source;

[0041] Step 14: Introduce the measuring gas from the first standard chamber into the first measuring chamber, and the measuring gas from the second standard chamber into the second measuring chamber, until the pressures of the first gas path and the second gas path reach equilibrium, and collect the equilibrium pressure data of the first gas path and the second gas path respectively.

[0042] Step 15: Based on the collected balance pressure data of the first and second gas paths, calculate the skeleton volume of the standard rock sample and the skeleton volume of the rock sample to be tested, respectively.

[0043] Compared with the prior art, the advantages of the present invention are as follows: The present invention adopts a dual-gas-path design. The first gas path is used to measure the standard rock sample with a known skeleton volume, and the second gas path is used to measure the rock sample to be tested with a skeleton volume to be measured. The sealing rings of the two measuring chambers have a linkage characteristic, so that the measurement results of the standard rock sample can be used as the measurement results of the rock sample to be tested and the indicator of the device status, thereby ensuring that the rock sample skeleton volume can be measured efficiently and accurately. Attached Figure Description

[0044] The invention will now be described in more detail with reference to embodiments and the accompanying drawings.

[0045] Figure 1 This is a schematic diagram of the structure of a rock sample skeleton volume measuring device in one embodiment of the present invention;

[0046] Figure 2 This is a flowchart of the method for determining the volume of a rock sample skeleton according to the present invention.

[0047] Figure label:

[0048] 1. First measuring chamber; 2. Second measuring chamber; 3. Filling device; 4. Conveying valve;

[0049] 5. First standard room; 6. Second standard room; 7. First valve; 8. Second valve;

[0050] 9. Third valve; 10. Air source; 11. Air source valve; 12. Control and calculation system;

[0051] 13. First pressure sensor; 14. Second pressure sensor; 15. Third pressure sensor;

[0052] 16. Fourth pressure sensor;

[0053] 101. First sealing ring; 102. First cup body; 103. First top cover;

[0054] 201. Second sealing ring; 202. Second cup body; 203. Second top cover. Detailed Implementation

[0055] The invention will now be further described with reference to the accompanying drawings.

[0056] like Figure 1 As shown, according to a first aspect of the present invention, the rock sample skeleton volume measuring device of the present invention includes: a first gas path for measuring a standard rock sample with a known skeleton volume and a second gas path for measuring a rock sample to be tested with a skeleton volume to be measured. The first gas path includes a first measuring chamber 1 for setting the standard rock sample, the first measuring chamber 1 including a first cup body 102 and a first top cover 103, the first cup body 102 and the first top cover 103 being sealed by a first sealing ring 101; the second gas path includes a second measuring chamber 2 for setting the rock sample to be tested, the second measuring chamber 2 including a second cup body 202 and a second top cover 203, the second cup body 202 and the second top cover 203 being sealed by a second sealing ring 201.

[0057] The first sealing ring 101 and the second sealing ring 201 are both fill-and-discharge type sealing rings, and the first sealing ring 101 and the second sealing ring 201 are interconnected.

[0058] Before the measurement, the skeleton volume of the standard rock sample is known and can be expressed by a nominal value; the measured value of the skeleton volume of the standard rock sample can be obtained by measuring through the first gas path.

[0059] The rock sample skeleton volume measuring device of the present invention has a dual-air-path structure. The first air-path is used to measure the volume of a standard rock sample with a known skeleton, and the second air-path is used to measure the volume of a rock sample to be tested. The sealing rings of the two measuring chambers have a linkage characteristic, which allows the measurement results of the standard rock sample to be used as the measurement results of the rock sample to be tested and as an indicator of the device status. This realizes the automatic identification of the sealing status of the device during the skeleton volume measurement process, improves the intelligence level of the device, and provides a new means for rapid and accurate measurement of rock sample skeleton volume and porosity.

[0060] It should be noted that by filling the sealing ring with a filling medium, the sealing ring expands, thereby achieving a seal between the cup body and the top cover of the corresponding measuring chamber. As long as the pressure inside the sealing ring is stable (no leakage occurs), the sealing effect of the sealing ring can be guaranteed.

[0061] Example 1

[0062] In this embodiment, the first sealing ring 101 and the second sealing ring 201 are sealing rings of the same material and specifications, and the first measuring chamber 1 and the second measuring chamber 2 are air chambers of the same material and specifications, so that the standard rock sample and the rock sample to be tested are in the same environment.

[0063] Specifically, the aforementioned filling and discharging sealing ring is either an air-filled sealing ring or a liquid-filled sealing ring.

[0064] The rock sample skeleton volume measuring device also includes a filling device 3 for providing filling medium. The filling device 3 is connected to the filling port of the first sealing ring 101 and the filling port of the second sealing ring 201 respectively through a delivery pipeline. A delivery valve 4 is provided on the delivery pipeline.

[0065] In other words, if the filling and discharging sealing ring is a pneumatic sealing ring, the filling medium provided by the filling device 3 is gas. If the filling and discharging sealing ring is a liquid-filled sealing ring, the filling medium provided by the filling device 3 is liquid. Preferably, the first sealing ring 101 and the second sealing ring 201 are pneumatic sealing rings, and the filling device 3 is a gas source 10 or an air pump.

[0066] It should be noted that the first sealing ring 101 and the second sealing ring 201 are connected by a pipeline, and the delivery pipeline of the filling device 3 is connected to the pipeline between the first sealing ring 101 and the second sealing ring 201, preferably at the middle position of the pipeline.

[0067] Preferably, such as Figure 1 As shown, the first measuring chamber 1 is disposed in the first support base. A first pressure rod is disposed on the top of the first top cover 103, and the first pressure rod is threadedly connected to the top of the first support base. By rotating the first pressure rod, the first top cover 103 can be moved vertically to adjust the distance between it and the first cup body 102, thereby controlling the opening and closing of the first top cover 103. Similarly, the second measuring chamber 2 is disposed in the second support base. A second pressure rod is disposed on the top of the second top cover 203, and the second pressure rod is threadedly connected to the top of the second support base. By rotating the second pressure rod, the second top cover 203 can be moved vertically to adjust the distance between it and the second cup body 202, thereby controlling the opening and closing of the second top cover 203.

[0068] Example 2

[0069] This embodiment describes the differences from the above embodiments, while the similarities will not be repeated.

[0070] In this embodiment, the first gas path further includes a first standard chamber 5, the outlet of which is connected to a first measuring chamber 1 via a pipeline, and a first valve 7 is installed on the pipeline between the first standard chamber 5 and the first measuring chamber 1. The second gas path further includes a second standard chamber 6, the outlet of which is connected to a second measuring chamber 2 via a pipeline, and a second valve 8 is installed on the pipeline between the second standard chamber 6 and the second measuring chamber 2.

[0071] The first standard chamber 5 and the second standard chamber 6 are air chambers with the same material and specifications. The first standard chamber 5 and the second standard chamber 6 are connected by a pipeline, and a third valve 9 is installed on the pipeline between the first standard chamber 5 and the second standard chamber 6.

[0072] In addition, the pipelines in the first gas line are the same as those in the second gas line in terms of material, specifications and volume.

[0073] In this embodiment, the first standard chamber 5 and the second standard chamber 6 are the same gas chambers, and opening the third valve 9 can connect the two to each other, thereby ensuring that the same pressure of gas can be introduced into the first standard chamber 5 and the second standard chamber 6, so that the first gas path and the second gas path have the same test environment and initial gas pressure, improving the accuracy of rock sample skeleton determination.

[0074] The rock sample skeleton volume measuring device also includes a gas source 10 that provides measuring gas. The gas source 10 is equipped with a gas source valve 11 at its outlet end. The gas source valve 11 is connected to the inlet end of the first standard chamber 5 and the inlet end of the second standard chamber 6 through corresponding pipelines.

[0075] In other words, the gas source 10 provides the device with gas at a certain pressure as the measuring medium. Specifically, the measuring gas provided by the gas source 10 is helium, nitrogen, or air.

[0076] Example 3

[0077] This embodiment describes the differences from the above embodiments, while the similarities will not be repeated.

[0078] In this embodiment, the rock sample skeleton volume measuring device further includes a detection system. The detection system includes a control and calculation system 12 and a first pressure sensor 13, a second pressure sensor 14, a third pressure sensor 15, and a fourth pressure sensor 16 connected to the control and calculation system 12. The first pressure sensor 13 is connected to the pipeline between the gas source valve 11 and the first standard chamber 5, the second pressure sensor 14 is connected to the pipeline between the gas source valve 11 and the second standard chamber 6, the third pressure sensor 15 is connected to the pipeline between the first valve 7 and the first measuring chamber 1, and the fourth pressure sensor 16 is connected to the pipeline between the second valve 8 and the second measuring chamber 2.

[0079] The aforementioned pressure sensor detects the gas pressure at a corresponding location during the test, which is used for calculating the volume of the rock sample skeleton. The control and calculation system 12 is used for receiving and converting the gas pressure sensor signal, and calculating the volume of the rock sample skeleton.

[0080] like Figure 2 As shown, according to a second aspect of the present invention, the method for measuring the volume of a rock sample skeleton, using the aforementioned rock sample skeleton volume measuring device, includes the following steps:

[0081] Step 1: Measure the skeleton volume of the standard rock sample through the first gas path, and simultaneously measure the skeleton volume of the rock sample to be tested through the second gas path.

[0082] Step 2: Compare the measured value and the nominal value of the skeleton volume of the standard rock sample. If the measured value and the nominal value of the skeleton volume of the standard rock sample are within the allowable error range, it is determined that the rock sample skeleton volume measuring device is well sealed and the measured value of the skeleton volume of the rock sample to be tested is accurate and reliable.

[0083] The rock sample skeleton volume determination method of the present invention performs skeleton volume determination simultaneously through dual gas paths. The first gas path is used to determine the volume of a standard rock sample with a known skeleton volume, and the second gas path is used to determine the volume of a rock sample to be tested. The sealing rings of the two measuring chambers have a linkage characteristic, so that the measurement result of the standard rock sample can be used as the measurement result of the rock sample to be tested and as an indicator of the device status, thereby ensuring that the rock sample skeleton volume can be determined efficiently and accurately.

[0084] Specifically, step 1 includes the following sub-steps:

[0085] Step 11: Place the standard rock sample with a known skeleton volume into the first measuring chamber 1, and place the rock sample with the skeleton volume to be measured into the second measuring chamber 2.

[0086] Step 12: Fill the first sealing ring 101 and the second sealing ring 201 simultaneously with the filling device 3 to seal the first measuring chamber 1 and the second measuring chamber 2.

[0087] Step 13: Inject the measuring gas at a preset pressure into the first standard chamber 5 and the second standard chamber 6 respectively through the gas source 10.

[0088] Step 14: The measuring gas in the first standard chamber 5 is introduced into the first measuring chamber 1, and the measuring gas in the second standard chamber 6 is introduced into the second measuring chamber 2, until the pressure in the first gas path and the second gas path reaches equilibrium, and the equilibrium pressure data of the first gas path and the second gas path are collected respectively.

[0089] Step 15: Based on the collected balance pressure data of the first and second gas paths, calculate the skeleton volume of the standard rock sample and the skeleton volume of the rock sample to be tested, respectively.

[0090] Example 4

[0091] The following describes in detail the process of measuring the volume of a rock sample skeleton using the rock sample skeleton volume measuring device of the present invention.

[0092] ① Place a standard rock sample with a known skeleton volume into the first cup body 102, rotate the first pressure rod to adjust the first top cover 103 to the corresponding position, so that the first sealing ring 101 can fit tightly against the first top cover 103 and the first cup body 102 after inflation, forming a sealed space between the first top cover 103 and the first cup body 102.

[0093] ② Place the rock sample to be tested into the second cup body 202, rotate the second pressure rod to adjust the second top cover 203 to the corresponding position, so that the second sealing ring 201 can fit tightly against the second top cover 203 and the second cup body 202 after inflation, forming a sealed space between the second top cover 203 and the second cup body 202.

[0094] ③ Open the conveying valve 4, start the filling device 3, and put the first sealing ring 101 and the second sealing ring 201 into an inflated and sealed state. Then close the filling device 3 and the conveying valve 4.

[0095] ④ Close the first valve 7 and the second valve 8, open the gas source valve 11 to allow the measuring gas to enter the first standard chamber 5 and the second standard chamber 6, and keep the third valve 9 in the open state.

[0096] ⑤ After the pressure measured by the first pressure sensor 13 and the second pressure sensor 14 stabilizes, record the pressure data at this time (initial pressure), and close the air source valve 11 and the third valve 9.

[0097] ⑥ Open the first valve 7 and the second valve 8 to allow the measuring gas in the first standard chamber 5 and the second measuring chamber 2 to enter the first measuring chamber 1 and the second measuring chamber 2 respectively. The gas pressure measured by the third pressure sensor 15 and the fourth pressure sensor 16 decreases until it stabilizes. Record the pressure data at this time. The pressure at this time is the equilibrium pressure.

[0098] ⑦ The control calculation system 12 calculates the skeleton volume of the known skeleton volume standard rock sample and the skeleton volume of the rock sample to be tested based on the detected pressure data, etc.

[0099] ⑧ Compare the measured and nominal values ​​of the skeleton volume of the standard rock sample. If they are within the allowable error range, it indicates that the equipment was functioning normally during the test, and the measured value of the rock sample to be tested can be used. Conversely, it indicates that the equipment was malfunctioning during the test, and the measured value of the rock sample to be tested cannot be used.

[0100] ⑨ Open the delivery valve 4 to unload the gas in the first sealing ring 101 and the second sealing ring 201, take out the standard rock sample and the rock sample to be tested, and end the test.

[0101] Example 5

[0102] A standard rock sample with a known skeleton volume is placed into the first cup 102. The first pressure rod is rotated to adjust the first top cover 103 to the corresponding position, so that the first sealing ring 101 can fit tightly against the first top cover 103 and the first cup 102 after inflation, forming a sealed space between the first top cover 103 and the first cup 102. The rock sample to be tested is placed into the second cup 202. The second pressure rod is rotated to adjust the second top cover 203 to the corresponding position, so that the second sealing ring 201 can fit tightly against the second top cover 203 and the second cup 202 after inflation, forming a sealed space between the second top cover 203 and the second cup 202. The delivery valve 4 is opened, and the filling device 3 is started to inflate and seal the first and second sealing rings 101. Then, the filling device 3 and the delivery valve 4 are closed. The first valve 7 and the second valve 8 are closed, the gas source valve 11 is opened to allow the measuring gas to enter the first standard chamber 5 and the second standard chamber 6, and the third valve 9 is opened. After the pressure measured by the first pressure sensor 13 and the second pressure sensor 14 stabilizes, record the pressure data (initial pressure) at this time, and close the gas source valve 11 and the third valve 9. Open the first valve 7 and the second valve 8 to allow the measuring gas in the first standard chamber 5 and the second measuring chamber 2 to enter the first measuring chamber 1 and the second measuring chamber 2 respectively. The gas pressure measured by the third pressure sensor 15 and the fourth pressure sensor 16 decreases until it stabilizes, and the pressure data at this time is recorded. This pressure is the equilibrium pressure. The control calculation system 12 calculates the skeleton volume of the known skeleton volume standard rock sample and the skeleton volume of the rock sample to be tested based on the detected pressure data, etc. Compare the measured value and the nominal value of the skeleton volume of the known skeleton volume standard rock sample. The relative error is less than 0.5%. This indicates that the test results of the standard rock sample are accurate, the equipment is normal during the test, and the measured value of the rock sample to be tested can be used. Open the delivery valve 4 to unload the gas in the first sealing ring 101 and the second sealing ring 201, take out the standard rock sample and the rock sample to be tested, and end the test.

[0103] Example 6

[0104] A standard rock sample with a known skeleton volume is placed into the first cup 102. The first pressure rod is rotated to adjust the first top cover 103 to the corresponding position, so that the first sealing ring 101 can fit tightly against the first top cover 103 and the first cup 102 after inflation, forming a sealed space between the first top cover 103 and the first cup 102. The rock sample to be tested is placed into the second cup 202. The second pressure rod is rotated to adjust the second top cover 203 to the corresponding position, so that the second sealing ring 201 can fit tightly against the second top cover 203 and the second cup 202 after inflation, forming a sealed space between the second top cover 203 and the second cup 202. The delivery valve 4 is opened, and the filling device 3 is started to inflate and seal the first and second sealing rings 101. Then, the filling device 3 and the delivery valve 4 are closed. The first valve 7 and the second valve 8 are closed, the gas source valve 11 is opened to allow the measuring gas to enter the first standard chamber 5 and the second standard chamber 6, and the third valve 9 is opened. After the pressure measured by the first pressure sensor 13 and the second pressure sensor 14 stabilizes, record the pressure data (initial pressure) at this time, and close the gas source valve 11 and the third valve 9. Open the first valve 7 and the second valve 8 to allow the measuring gas in the first standard chamber 5 and the second measuring chamber 2 to enter the first measuring chamber 1 and the second measuring chamber 2 respectively. The gas pressure measured by the third pressure sensor 15 and the fourth pressure sensor 16 decreases until it stabilizes, and the pressure data at this time is recorded. This pressure is the equilibrium pressure. The control calculation system 12 calculates the skeleton volume of the known skeleton volume standard rock sample and the skeleton volume of the rock sample to be tested based on the detected pressure data, etc. Compare the measured value and the nominal value of the skeleton volume of the known skeleton volume standard rock sample. It is found that the measured value is greater than the nominal value, and the relative error is greater than 0.5%. The test result of the standard rock sample has a large deviation, and there may be leakage of the sealing ring during the test. The measured value of the rock sample to be tested cannot be used. Open the delivery valve 4 to unload the gas in the first sealing ring 101 and the second sealing ring 201, take out the standard rock sample and the rock sample to be tested, and end the test.

[0105] As a specific application example: During the rock sample testing process, the pressure change curves of the first measuring chamber 1 and the second measuring chamber 2 are collected by the control calculation system 12. When the known skeleton volume standard rock sample and the rock sample to be tested have similar mineral composition and other properties, and the initial gas pressure and testing environment of the two are the same, the comparative analysis of the pressure change curves is of positive significance for the comparative study of their permeability and pore structure.

[0106] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0107] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include one or more of that feature.

[0108] Although the invention has been described with reference to preferred embodiments, various modifications can be made and components can be replaced with equivalents without departing from the scope of the invention. In particular, the technical features mentioned in the various embodiments can be combined in any manner as long as there is no structural conflict. The invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A method for determining the volume of a rock sample skeleton, characterized in that, The method for determining the volume of a rock sample skeleton uses a rock sample skeleton volume measuring device, which includes: a first gas path for measuring the volume of a standard rock sample with a known skeleton volume, and a second gas path for measuring the volume of the rock sample to be tested. The first gas path includes a first measuring chamber for setting the standard rock sample, the first measuring chamber including a first cup body and a first top cover, the first cup body and the first top cover being sealed by a first sealing ring; the second gas path includes a second measuring chamber for setting the rock sample to be tested, the second measuring chamber including a second cup body and a second top cover, the second cup body and the second top cover being sealed by a second sealing ring; Wherein, both the first sealing ring and the second sealing ring are inflatable sealing rings, and the first sealing ring and the second sealing ring are interconnected; The method for determining the volume of the rock sample skeleton includes the following steps: Step 1: Measure the skeleton volume of the standard rock sample through the first gas path, and simultaneously measure the skeleton volume of the rock sample to be tested through the second gas path. Step 2: Compare the measured value and nominal value of the skeleton volume of the standard rock sample. If the measured value and nominal value of the skeleton volume of the standard rock sample are within the allowable error range, it is determined that the rock sample skeleton volume measuring device is well sealed and the measured value of the skeleton volume of the rock sample to be tested is accurate and reliable. If the relative error between the measured value and nominal value of the skeleton volume of the standard rock sample exceeds the allowable error range, it is determined that the rock sample skeleton volume measuring device is abnormal and the measured value of the skeleton volume of the rock sample to be tested is unusable. Step 1 includes the following sub-steps: Step 11: Place the standard rock sample with a known skeleton volume into the first measuring chamber, and place the rock sample with the skeleton volume to be measured into the second measuring chamber; Step 12: Simultaneously fill the first sealing ring and the second sealing ring with filling medium through the filling device to seal the first measuring chamber and the second measuring chamber; Step 13: Inject the measuring gas at a preset pressure into the first standard chamber and the second standard chamber respectively through the gas source; Step 14: Introduce the measuring gas from the first standard chamber into the first measuring chamber, and the measuring gas from the second standard chamber into the second measuring chamber, until the pressures of the first gas path and the second gas path reach equilibrium, and collect the equilibrium pressure data of the first gas path and the second gas path respectively. Step 15: Based on the collected balance pressure data of the first and second gas paths, calculate the skeleton volume of the standard rock sample and the skeleton volume of the rock sample to be tested, respectively.

2. The method for determining the volume of a rock sample skeleton according to claim 1, characterized in that, The first sealing ring and the second sealing ring are sealing rings of the same material and specifications; The first measuring chamber and the second measuring chamber are air chambers with the same material and specifications.

3. The method for determining the volume of a rock sample skeleton according to claim 2, characterized in that, The filling and discharging sealing ring is either an air-filled sealing ring or a liquid-filled sealing ring.

4. The method for determining the volume of a rock sample skeleton according to any one of claims 1-3, characterized in that, It also includes a filling device, which is connected to the filling port of the first sealing ring and the filling port of the second sealing ring respectively through a delivery pipeline, and the delivery pipeline is equipped with a delivery valve.

5. The method for determining the volume of a rock sample skeleton according to any one of claims 1-3, characterized in that, The first gas path also includes a first standard chamber, the outlet of which is connected to the first measuring chamber via a pipeline, and a first valve is installed on the pipeline between the first standard chamber and the first measuring chamber. The second gas path also includes a second standard chamber, the outlet of which is connected to the second measuring chamber via a pipeline, and a second valve is installed on the pipeline between the second standard chamber and the second measuring chamber. The first standard chamber and the second standard chamber are air chambers with the same material and specifications. The first standard chamber and the second standard chamber are connected by a pipeline, and a third valve is installed on the pipeline between the first standard chamber and the second standard chamber.

6. The method for determining the volume of a rock sample skeleton according to claim 5, characterized in that, It also includes a gas source for providing the measuring gas, wherein the outlet end of the gas source is provided with a gas source valve, and the gas source valve is connected to the inlet end of the first standard chamber and the inlet end of the second standard chamber through corresponding pipelines.

7. The method for determining the volume of a rock sample skeleton according to claim 6, characterized in that, The measuring gas is helium, nitrogen, or air.

8. The method for determining the volume of a rock sample skeleton according to claim 6, characterized in that, It also includes a detection system, which comprises a control computing system and a first pressure sensor, a second pressure sensor, a third pressure sensor, and a fourth pressure sensor connected to the control computing system. The first pressure sensor is connected to the pipeline between the gas source valve and the first standard chamber, the second pressure sensor is connected to the pipeline between the gas source valve and the second standard chamber, the third pressure sensor is connected to the pipeline between the first valve and the first measuring chamber, and the fourth pressure sensor is connected to the pipeline between the second valve and the second measuring chamber.

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