Geological Core Permeability Testing Device and Method

Abstract

The present invention discloses a geological core permeability testing device and method, which relates to the technical field of physical property analysis of geological cores, and includes a nuclear magnetic resonance unit, an acoustic wave propagation testing unit, a pressure testing unit, and a permeability analysis and calculation unit. By combining three different methods of NMR, acoustic wave propagation testing, and pressure testing, the present invention can more comprehensively evaluate the permeability of geological cores. Both NMR and acoustic wave propagation testing are non-destructive methods, which can be tested multiple times without damaging the core samples, maintaining the integrity of the samples and facilitating subsequent other analyses. The permeability values obtained from NMR and acoustic wave propagation testing are used to calibrate the permeability values obtained from pressure testing, improving the accuracy of the final permeability value and reducing the errors caused by a single testing method. An efficient, accurate, and environmentally friendly geological core permeability testing device is provided, which helps to improve the economic benefits of oil and gas field development.

Description

Technical Field

[0001] The present invention relates to the technical field of physical property analysis of geological cores, and particularly to a device and method for testing the permeability of geological cores. Background Art

[0002] Core permeability refers to the ability of fluids (such as water, oil, and gas) to pass through the pores of rocks, and is one of the important parameters for evaluating the properties of rock reservoirs. The magnitude of permeability directly affects the reservoir quality of rocks and the fluid migration ability, and is a key indicator for evaluating the development potential of oil and gas fields.

[0003] The existing methods for measuring core permeability mainly include the mercury injection method, the osmotic pressure difference method, and the permeability test method.

[0004] The mercury injection method calculates the permeability by measuring the pore volume of the core infiltrated by mercury under a certain pressure. The mercury injection method is a destructive testing method because it requires injecting mercury into the rock pores, which may permanently change the structure of the rock. Mercury is a toxic substance, and there is a risk of mercury leakage and environmental pollution during the operation. This method assumes that the interaction between mercury and rock pores can be ignored, but in fact, mercury may interact with the rock surface, affecting the measurement results.

[0005] This method is more suitable for rock samples with high porosity and good pore connectivity. For rocks with low porosity or complex pore structures, its accuracy will decrease.

[0006] The osmotic pressure difference method places the core sample in a permeameter and calculates the permeability by measuring the velocity of the fluid passing through the core by applying a certain pressure difference. This method requires selecting an appropriate fluid for testing, and different fluids may interact differently with the rock, affecting the measurement results. For rock samples with low permeability, the velocity of the fluid passing through the core may be very slow, resulting in a long testing time. The preparation of the sample needs to be very precise, and any minor defect or crack may cause deviation of the fluid flow path, thus affecting the measurement of permeability.

[0007] The permeability test method places the core sample in a permeameter, applies a certain pressure difference, and calculates the permeability by measuring the volume and time of the fluid passing through the core. Since the volume and time of the fluid passing through the core are measured, the test results may be affected by time. Especially in long-term tests, changes in fluid properties may affect the results. The saturation of the sample must be uniform and consistent, otherwise it will affect the flow behavior of the fluid and the calculation of permeability. This method usually requires the core sample to have a certain size and shape, and may not be applicable to irregular or small-sized samples. Summary of the Invention

[0008] To solve the above technical problems, the present invention provides a geological core permeability testing device and method. The following technical solutions are adopted:

[0009] A geological core permeability testing device includes a nuclear magnetic resonance unit, an acoustic wave propagation testing unit, a pressure testing unit, and a permeability analysis and calculation unit;

[0010] The nuclear magnetic resonance unit is used to perform NMR testing on a geological core sample to obtain a first permeability value of the core sample;

[0011] The sample inlet of the acoustic wave propagation testing unit is communicated with the sample outlet of the nuclear magnetic resonance unit. The acoustic wave propagation testing unit is used to perform acoustic wave propagation testing on a geological core sample to obtain a second permeability value of the core sample;

[0012] The pressure testing unit is used to perform confining pressure testing on a geological core sample under simulated formation pressure conditions to obtain a third permeability value of the core sample;

[0013] The permeability analysis and calculation unit communicates and exchanges test results with the nuclear magnetic resonance unit, the acoustic wave propagation testing unit, and the pressure testing unit respectively, and calibrates the third permeability value by using the first permeability value and the second permeability value to output the geological core permeability value.

[0014] By adopting the above technical solutions, by combining three different methods of NMR, acoustic wave propagation testing, and pressure testing, the permeability of geological cores can be evaluated more comprehensively. Both NMR and acoustic wave propagation testing are non-destructive methods, and multiple tests can be carried out without damaging the core sample, maintaining the integrity of the sample and facilitating subsequent other analyses.

[0015] NMR testing provides information about porosity, pore size distribution, and fluid type. Acoustic wave propagation testing provides information about the elastic properties and pore structure of the core, while pressure testing simulates actual formation conditions. These multi-parameter measurements help to understand the core's permeability characteristics more deeply.

[0016] By calibrating the permeability value obtained by pressure testing with the permeability values obtained by using NMR and acoustic wave propagation testing, the accuracy of the final permeability value can be improved, and the error that may be brought by a single testing method is reduced.

[0017] Through automation and data integration, the time for manual operation and data processing is reduced, and the testing efficiency is improved.

[0018] The device can adapt to different types of cores and samples with different permeability ranges, and is applicable to a variety of geological exploration and development scenarios.

[0019] Through the comprehensive analysis of data from different test units by the permeability analysis calculation unit, the unity and consistency of the final permeability data can be ensured.

[0020] An efficient, accurate, and environmentally friendly geological core permeability testing device is provided, which helps to improve the economic efficiency and safety of oil and gas field development.

[0021] Optionally, it further includes a sample injection unit. The sample injection unit includes a cleaning device and a drying device. The cleaning device is provided with an inlet for geological core samples. The cleaning device is used to remove impurities on the surface of the core sample. The drying device is used to dry the core sample after cleaning. An outlet is provided at the bottom of the sample injection unit, and an electric control door is installed at the outlet. When the drying device completes the drying operation, the electric control door is opened, and the core sample falls into the sample inlet of the nuclear magnetic resonance unit.

[0022] By adopting the above technical solution, the cleaning device gently cleans the surface of the core sample with a non-polluting cleaning agent to remove impurities. The cleaned core sample is placed in the drying device to remove excess water, which can ensure the accuracy of subsequent test results.

[0023] Optionally, the nuclear magnetic resonance unit includes a sample injection tube and a nuclear magnetic resonance rock sample analyzer. The inlet of the sample injection tube is communicated with the outlet of the sample injection unit. When the electric control door is opened, the core sample falls through the sample injection tube onto the sample stage of the nuclear magnetic resonance rock sample analyzer. The nuclear magnetic resonance rock sample analyzer performs NMR testing on the sample and outputs the first permeability value.

[0024] By adopting the above technical solution, the nuclear magnetic resonance rock sample analyzer can perform NMR testing and directly output the first permeability value.

[0025] Optionally, the acoustic wave propagation test unit includes an acoustic wave propagation test chamber, an acoustic wave generator, an acoustic wave receiver, an oscilloscope, a signal amplifier, and a chip-based acoustic wave propagation test analysis module. A sample channel tube is provided in the center of the top of the acoustic wave propagation test chamber. The acoustic wave generator and the acoustic wave receiver are symmetrically installed on the inner wall of the acoustic wave propagation test chamber. When the rock sample after NMR testing falls onto the test stage in the middle of the acoustic wave propagation test chamber, the acoustic wave generator emits test acoustic waves towards the middle of the rock sample. The acoustic wave receiver receives the acoustic waves propagated back from the rock sample and converts them into electrical signals and transmits them to the signal amplifier. The oscilloscope is communicatively connected to the signal amplifier. The acoustic wave propagation test analysis module communicatively interacts with the data output port of the oscilloscope for acoustic wave signals and analyzes the collected acoustic wave signals to calculate the second permeability value.

[0026] By adopting the above technical solution, the rock sample that has completed the NMR test falls into the test bench in the middle of the acoustic wave propagation test chamber through the sample channel tube. The acoustic wave generator is activated and emits test acoustic waves with a certain frequency and amplitude towards the middle of the rock sample. These acoustic waves can be pulsed waves or continuous waves, depending on the test requirements and sample characteristics.

[0027] After the acoustic waves propagate through the rock sample, they are received by the acoustic wave receiver. The receiver records the time delay and amplitude change of the acoustic wave propagation. The acoustic wave receiver converts the received acoustic wave signal into an electrical signal and then transmits it to the signal amplifier for amplification processing for subsequent analysis. The oscilloscope is connected to the signal amplifier and is used to display and record the amplified electrical signal. This helps the operator observe the real-time changes of the acoustic wave signal. The acoustic wave propagation test analysis module communicates with the data output port of the oscilloscope and acquires the acoustic wave signal data displayed by the oscilloscope. The acoustic wave propagation test analysis module uses specific algorithms to process the acquired acoustic wave signals, and these algorithms may include time-domain analysis, frequency-domain analysis, waveform analysis, etc.

[0028] Optionally, the pressure test unit includes a pressure test chamber, a pressure simulation module, a pressure test container, a fluid medium injection device, a micro flow sensor, a chip-based pressure controller, and a chip-based pressure test analysis module. The pressure test container is installed in the pressure test chamber. After a core sample is placed in the pressure test container, the pressure simulation module is activated to simulate formation pressure in the pressure test chamber. The pressure controller controls the fluid medium injection device to inject a liquid medium with a set pressure at both ends of the core sample. The micro flow sensor is used to monitor the flow rate of the liquid medium. The pressure test analysis module is communicatively connected to the pressure controller and the micro flow sensor, exchanges the pressure values and fluid flow rates at both ends of the core sample, and calculates the third permeability value.

[0029] By adopting the above technical solution, the core sample that has completed the NMR and acoustic wave propagation tests is placed in the pressure test container. The pressure test container is sealed and prepared for the pressure test. The pressure simulation module is started to simulate formation pressure conditions in the pressure test chamber. This usually involves adjusting the temperature and pressure to predetermined simulated values. The pressure controller activates the fluid medium injection device and starts to inject a liquid medium with a set pressure at both ends of the core sample. The injected pressure should be increased gradually to simulate actual formation pressure conditions. The fluid medium can be saturated brine, kerosene, or light oil, etc. The micro flow sensor monitors and records the flow rate of the liquid medium injected at both ends of the core sample in real time. The flow rate data is crucial for subsequent permeability calculations. The pressure test analysis module communicates with the pressure controller and the micro flow sensor, acquires the pressure values and fluid flow rates at both ends of the core sample. Maintain the pressure for a period of time until the pressure and flow rate reach a stable state.

[0030] Optionally, the permeability analysis calculation unit includes a data acquisition module, a data memory, and a data analysis computer. The data acquisition module is respectively communicatively connected to the data output ends of the nuclear magnetic resonance core analyzer, the acoustic wave propagation test analysis module, and the pressure test analysis module. The data memory is communicatively connected to the data acquisition module, and the data analysis computer is communicatively connected to the data memory. Based on the collected first permeability value, second permeability value, and third permeability value, the geological core permeability value is calculated and output.

[0031] By adopting the above technical solution, the data analysis computer can calculate and output the geological core permeability value based on the three permeability values collected by the data acquisition module.

[0032] For the geological core permeability test method, a geological core permeability test device is used to test the permeability of the core sample, including the following steps:

[0033] Step 1: Select the core sample to be tested from the core library and place the core sample into the sample inlet of the sample injection unit.

[0034] Step 2: Place the cleaned and air-dried core sample into the sample injection tube of the nuclear magnetic resonance unit. The nuclear magnetic resonance core analyzer performs NMR testing on the core sample and outputs the first permeability value.

[0035] Step 3: Place the core sample that has completed the NMR test on the test bench in the middle of the acoustic wave propagation test chamber. The acoustic wave propagation test unit performs acoustic wave propagation testing on the geological core sample to obtain the second permeability value of the core sample.

[0036] Step 4: Place the core sample that has completed the acoustic wave propagation test into the pressure test container of the pressure test unit. The pressure test unit performs confining pressure testing on the geological core sample to obtain the third permeability value of the core sample.

[0037] Step 5: The data analysis computer uses the first permeability value and the second permeability value to calibrate the third permeability value and outputs the calibrated geological core permeability value.

[0038] Optionally, the formula for calculating the first permeability value is:

[0039] ;

[0040] Where is the first permeability value, A is the NMR test proportionality constant, is the transverse relaxation time in the NMR test, is the adjustment exponent, used to adjust the contribution of the value to the permeability estimation, is the volume element, and n is the influence exponent, which determines The influence degree of the integral value of the distribution on the permeability estimation denotes an integral operation with respect to the pore volume having different

[0041] Optionally, in step 3, the formula for calculating the second permeability value is:

[0042] ;

[0043] wherein is the second permeability value, C is the proportionality constant of the acoustic velocity to the permeability, is the longitudinal wave velocity of the acoustic wave in the rock sample, is the correlation index of the acoustic velocity to the permeability.

[0044] Optionally, in step 4, the formula for calculating the third permeability value is:

[0045] ;

[0046] wherein is the third permeability value, Q is the flow rate of the fluid medium, is the viscosity of the fluid medium, is the length of the core sample, A is the cross-sectional area of the core sample, and are the pressure values at both ends of the core sample respectively;

[0047] The formula for calibrating the third permeability value to obtain the geological core permeability value is:

[0048] .

[0049] In summary, the present invention includes at least one of the following beneficial technical effects:

[0050] The present invention can provide a geological core permeability testing device and method. By combining three different methods of NMR, acoustic wave propagation testing, and pressure testing, the permeability of geological cores can be more comprehensively evaluated. Both NMR and acoustic wave propagation testing are non-destructive methods, and multiple tests can be carried out without damaging the core sample, maintaining the integrity of the sample and facilitating subsequent other analyses.

[0051] The permeability values obtained from NMR and acoustic wave propagation testing are calibrated against the permeability value obtained from pressure testing, improving the accuracy of the final permeability value and reducing the error caused by a single testing method.

[0052] The device can adapt to different types of cores and samples with different permeability ranges, and is applicable to a variety of geological exploration and development scenarios.

[0053] Through the comprehensive analysis of data from different test units by the permeability analysis and calculation unit, the unity and consistency of the final permeability data can be ensured.

[0054] An efficient, accurate and environmentally friendly geological core permeability testing device is provided, which helps to improve the economic benefits of oil and gas field development. Description of the Drawings

[0055] Figure 1 It is a schematic diagram of the component structure principle of the geological core permeability testing device of the present invention;

[0056] Figure 2 It is a schematic diagram of the electrical component connection principle of the geological core permeability testing device of the present invention;

[0057] Figure 3 It is a schematic flowchart of the geological core permeability testing method of the present invention.

[0058] Description of the reference numerals: 11, cleaning device; 12, air drying device; 21, sample injection tube; 22, nuclear magnetic resonance rock sample analyzer; 31, acoustic wave propagation test chamber; 311, sample channel tube; 312, test bench; 32, acoustic wave generator; 33, acoustic wave receiver; 34, oscilloscope; 35, signal amplifier; 36, acoustic wave propagation test and analysis module; 41, pressure test chamber; 42, pressure simulation module; 43, pressure test container; 44, fluid medium injection device; 45, micro flow sensor; 46, pressure controller; 47, pressure test and analysis module; 51, data acquisition module; 52, data memory; 53, data analysis computer. Detailed Embodiments

[0059] The present invention will be further described in detail below with reference to the accompanying drawings.

[0060] The embodiments of the present invention disclose a geological core permeability testing device and method.

[0061] Referring to Figures 1-3 , Embodiment 1, a geological core permeability testing device, including a nuclear magnetic resonance unit, an acoustic wave propagation test unit, a pressure test unit and a permeability analysis and calculation unit;

[0062] The nuclear magnetic resonance unit is used to perform NMR testing on geological core samples to obtain the first permeability value of the core samples;

[0063] The sample inlet of the acoustic wave propagation test unit is connected to the sample outlet of the nuclear magnetic resonance unit. The acoustic wave propagation test unit is used to perform acoustic wave propagation tests on geological core samples to obtain the second permeability value of the core samples;

[0064] The pressure test unit is used to perform confining pressure tests on geological core samples under simulated formation pressure conditions to obtain the third permeability value of the core samples;

[0065] The permeability analysis and calculation unit communicates and interacts with the nuclear magnetic resonance unit, the acoustic wave propagation test unit, and the pressure test unit for test results, and calibrates the third permeability value using the first permeability value and the second permeability value to output the geological core permeability value.

[0066] By combining three different methods of NMR, acoustic wave propagation test, and pressure test, the permeability of geological cores can be evaluated more comprehensively. Both NMR and acoustic wave propagation tests are non-destructive methods, which can be tested multiple times without damaging the core samples, maintaining the integrity of the samples and facilitating subsequent other analyses.

[0067] The NMR test provides information on porosity, pore size distribution, and fluid type. The acoustic wave propagation test provides information on the elastic properties and pore structure of the core. The pressure test simulates the actual formation conditions. These multi-parameter measurements help to understand the core's permeability characteristics more deeply.

[0068] By calibrating the permeability value obtained from the pressure test using the permeability values obtained from NMR and acoustic wave propagation tests, the accuracy of the final permeability value can be improved, reducing the errors that may be brought by a single test method.

[0069] Through automation and data integration, the time for manual operation and data processing is reduced, and the test efficiency is improved.

[0070] The device can adapt to different types of cores and samples with different permeability ranges, and is applicable to a variety of geological exploration and development scenarios.

[0071] By comprehensively analyzing the data from different test units through the permeability analysis and calculation unit, the unity and consistency of the final permeability data can be ensured.

[0072] A high-efficiency, accurate, and environmentally friendly geological core permeability test device is provided, which helps to improve the economic benefits and safety of oil and gas field development.

[0073] Example 2 further includes a sample injection unit, which includes a cleaning device 11 and a drying device 12. The cleaning device 11 is provided with a geological core sample inlet. The cleaning device 11 is used to remove impurities on the surface of the core sample. The drying device 12 is used to dry the core sample after cleaning. An outlet is provided at the bottom of the sample injection unit, and an electric control door is installed at the outlet. When the drying device 12 completes the drying operation, the electric control door is opened, and the core sample falls into the sample inlet of the nuclear magnetic resonance unit.

[0074] The cleaning device 11 gently cleans the surface of the core sample with a non-polluting cleaning agent to remove impurities. The cleaned core sample is placed in the drying device 12 to remove excess water, which can ensure the accuracy of subsequent test results.

[0075] Example 3, the nuclear magnetic resonance unit includes a sample injection tube 21 and a nuclear magnetic resonance rock sample analyzer 22. The inlet of the sample injection tube 21 is communicated with the outlet of the sample injection unit. When the electric control door is opened, the core sample falls through the sample injection tube 21 onto the sample stage of the nuclear magnetic resonance rock sample analyzer 22, and the nuclear magnetic resonance rock sample analyzer 22 performs an NMR test on the sample and outputs a first permeability value.

[0076] The nuclear magnetic resonance rock sample analyzer 22 can perform an NMR test and directly output a first permeability value.

[0077] Example 4, the acoustic wave propagation test unit includes an acoustic wave propagation test chamber 31, an acoustic wave generator 32, an acoustic wave receiver 33, an oscilloscope 34, a signal amplifier 35, and a chip-based acoustic wave propagation test analysis module 36. A sample channel tube 311 is provided at the center of the top of the acoustic wave propagation test chamber 31. The acoustic wave generator 32 and the acoustic wave receiver 33 are symmetrically installed on the inner wall of the acoustic wave propagation test chamber 31. When the rock sample after the NMR test falls onto the test bench 312 in the middle of the acoustic wave propagation test chamber 31, the acoustic wave generator 32 emits test acoustic waves towards the middle of the rock sample. The acoustic wave receiver 33 receives the acoustic waves propagated back from the rock sample and converts them into electrical signals and transmits them to the signal amplifier 35. The oscilloscope 34 is communicatively connected to the signal amplifier 35. The acoustic wave propagation test analysis module 36 communicatively interacts with the data output port of the oscilloscope 34 for acoustic wave signals and analyzes the collected acoustic wave signals to calculate a second permeability value.

[0078] The rock sample that has completed the NMR test falls through the sample channel tube 311 onto the test bench 312 in the middle of the acoustic wave propagation test chamber 31. The acoustic wave generator 32 is activated to emit test acoustic waves with a certain frequency and amplitude towards the middle of the rock sample. These acoustic waves can be pulse waves or continuous waves, depending on the test requirements and sample characteristics.

[0079] After the sound wave propagates through the rock sample, it is received by the sound wave receiver 33. The receiver records the time delay and amplitude change of the sound wave propagation. The sound wave receiver 33 converts the received sound wave signal into an electrical signal and then transmits it to the signal amplifier 35 for amplification processing to facilitate subsequent analysis. The oscilloscope 34 is connected to the signal amplifier 35 and is used to display and record the amplified electrical signal. This helps the operator observe the real-time changes of the sound wave signal. The sound wave propagation test analysis module 36 communicates with the data output port of the oscilloscope 34 to collect the sound wave signal data displayed by the oscilloscope 34. The sound wave propagation test analysis module 36 processes the collected sound wave signal using specific algorithms, which may include time-domain analysis, frequency-domain analysis, waveform analysis, etc.

[0080] In Embodiment 5, the pressure test unit includes a pressure test chamber 41, a pressure simulation module 42, a pressure test container 43, a fluid medium injection device 44, a micro flow sensor 45, a chip-based pressure controller 46, and a chip-based pressure test analysis module 47. The pressure test container 43 is installed in the pressure test chamber 41. After the core sample is placed in the pressure test container 43, the pressure simulation module 42 is activated to simulate the formation pressure in the pressure test chamber 41. The pressure controller 46 controls the fluid medium injection device 44 to inject a liquid medium with a set pressure at both ends of the core sample. The micro flow sensor 45 is used to monitor the flow rate of the liquid medium. The pressure test analysis module 47 is communicatively connected to the pressure controller 46 and the micro flow sensor 45 to interact the pressure values and fluid flow rate values at both ends of the core sample and calculate the third permeability value.

[0081] The core sample that has completed the NMR and sound wave propagation tests is placed in the pressure test container 43. The pressure test container 43 is sealed and prepared for the pressure test. The pressure simulation module 42 is activated to simulate the formation pressure conditions in the pressure test chamber 41. This usually involves adjusting the temperature and pressure to predetermined simulated values. The pressure controller 46 activates the fluid medium injection device 44 to start injecting a liquid medium with a set pressure at both ends of the core sample. The injected pressure should be gradually increased to simulate the actual formation pressure conditions. The fluid medium can be saturated brine, kerosene, light oil, etc. The micro flow sensor 45 monitors and records the flow rate of the liquid medium injected at both ends of the core sample in real time. The flow rate data is crucial for subsequent permeability calculations. The pressure test analysis module 47 communicates with the pressure controller 46 and the micro flow sensor 45 to collect the pressure values and fluid flow rate values at both ends of the core sample. Maintain the pressure for a period of time until the pressure and flow rate reach a steady state.

[0082] Example 6. The permeability analysis and calculation unit includes a data acquisition module 51, a data memory 52, and a data analysis computer 53. The data acquisition module 51 is respectively communicatively connected to the data output ends of the nuclear magnetic resonance core analyzer 22, the acoustic wave propagation test and analysis module 36, and the pressure test and analysis module 47. The data memory 52 is communicatively connected to the data acquisition module 51, and the data analysis computer 53 is communicatively connected to the data memory 52. The geological core permeability value is calculated and output based on the collected first permeability value, second permeability value, and third permeability value.

[0083] The data analysis computer 53 can calculate and output the geological core permeability value based on the three permeability values collected by the data acquisition module 51.

[0084] Example 7. A geological core permeability test method uses a geological core permeability test device to test the permeability of a core specimen, including the following steps:

[0085] Step 1: Select a core sample to be tested from the core library and place the core sample into the sample inlet of the sample injection unit.

[0086] Step 2: Place the cleaned and air-dried core sample into the sample injection tube 21 of the nuclear magnetic resonance unit. The nuclear magnetic resonance core analyzer 22 performs NMR testing on the core sample and outputs the first permeability value.

[0087] Step 3: Place the core sample that has completed the NMR test on the test bench 312 in the middle of the acoustic wave propagation test chamber 31. The acoustic wave propagation test unit performs an acoustic wave propagation test on the geological core sample to obtain the second permeability value of the core sample.

[0088] Step 4: Place the core sample that has completed the acoustic wave propagation test into the pressure test container 43 of the pressure test unit. The pressure test unit performs a confining pressure test on the geological core sample to obtain the third permeability value of the core sample.

[0089] Step 5: The data analysis computer 53 uses the first permeability value and the second permeability value to calibrate the third permeability value and outputs the calibrated geological core permeability value.

[0090] Example 8. The formula for calculating the first permeability value is:

[0091] ;

[0092] Where is the first permeability value, A is the NMR test proportional constant, is the transverse relaxation time in the NMR test, is the adjustment exponent used to adjust the contribution of the value to the permeability estimation, is the volume element, and n is the influence index, which determines the influence degree of the integral value of the distribution on the permeability estimation, denotes the integral operation with respect to This integral operation is the weighted sum of the pore volumes with different values.

[0093] In Example 9, Step 3, the formula for calculating the second permeability value is:

[0094] ;

[0095] where is the second permeability value, C is the proportionality constant between the acoustic velocity and the permeability, is the longitudinal wave velocity of the acoustic wave in the rock sample, is the correlation index between the acoustic velocity and the permeability.

[0096] In Example 10, Step 4, the formula for calculating the third permeability value is:

[0097] ;

[0098] where is the third permeability value, Q is the fluid medium flow rate, is the viscosity of the fluid medium, is the length of the core sample, A is the cross-sectional area of the core sample, and are the pressure values at both ends of the core sample respectively;

[0099] The formula for calibrating the third permeability value to obtain the geological core permeability value is:

[0100] .

[0101] The above are all the preferred embodiments of the present invention, and the protection scope of the present invention is not limited thereby. Therefore, all equivalent changes made according to the structure, shape, and principle of the present invention should be covered within the protection scope of the present invention.

Claims

1. Geological core permeability testing device, characterized in that: It includes a nuclear magnetic resonance unit, an acoustic wave propagation test unit, a pressure test unit, and a permeability analysis and calculation unit; The nuclear magnetic resonance unit is used to perform NMR tests on geological core samples to obtain the first permeability value of the core samples; The sample inlet of the acoustic wave propagation test unit is connected to the sample outlet of the nuclear magnetic resonance unit. The acoustic wave propagation test unit is used to perform acoustic wave propagation tests on geological core samples to obtain the second permeability value of the core samples; The pressure test unit is used to perform confining pressure tests on geological core samples under simulated formation pressure conditions to obtain the third permeability value of the core samples; The permeability analysis and calculation unit communicates with the nuclear magnetic resonance unit, the acoustic wave propagation test unit, and the pressure test unit to interact with the test results, and calibrates the third permeability value using the first permeability value and the second permeability value to output the geological core permeability value; The formula for calculating the first permeability value is: ； wherein is the first permeability value, A is the NMR test proportionality constant, is the transverse relaxation time in the NMR test, is the adjustment exponent for adjusting the contribution of the value to the permeability estimation, is the volume element, n is the influence exponent that determines the influence degree of the integral value of the distribution on the permeability estimation, represents the integral operation with respect to ; The formula for calculating the second permeability value is: ； wherein is the second permeability value, C is the proportionality constant between the acoustic velocity and the permeability, is the longitudinal wave velocity of the acoustic wave in the rock sample, is the correlation exponent between the acoustic velocity and the permeability; The formula for calculating the third permeability value is: ； wherein is the third permeability value, Q is the flow rate of the fluid medium, is the viscosity of the fluid medium, is the length of the core sample, A is the cross-sectional area of the core sample, and are the pressure values at both ends of the core sample, respectively; Calibrate the third permeability value to obtain the geological core permeability value The formula is: 。 2. The geological core permeability testing device according to claim 1, wherein: It further includes a sample injection unit. The sample injection unit includes a cleaning device (11) and a drying device (12). The cleaning device (11) is provided with a geological core sample inlet. The cleaning device (11) is used to remove impurities on the surface of the core sample. The drying device (12) is used to dry the core sample after cleaning. An outlet is provided at the bottom of the sample injection unit, and an electric control door is installed at the outlet. When the drying device (12) completes the drying operation, the electric control door is opened, and the core sample falls into the sample inlet of the nuclear magnetic resonance unit.

3. The geological core permeability testing device according to claim 2, wherein: The nuclear magnetic resonance unit includes a sample injection tube (21) and a nuclear magnetic resonance rock sample analyzer (22). The inlet of the sample injection tube (21) is connected to the outlet of the sample injection unit. When the electric control door is opened, the core sample falls through the sample injection tube (21) onto the sample stage of the nuclear magnetic resonance rock sample analyzer (22). The nuclear magnetic resonance rock sample analyzer (22) performs NMR tests on the sample and outputs the first permeability value.

4. The geological core permeability testing device according to claim 3, wherein: The acoustic wave propagation test unit includes an acoustic wave propagation test chamber (31), an acoustic wave generator (32), an acoustic wave receiver (33), an oscilloscope (34), a signal amplifier (35), and a chip-based acoustic wave propagation test analysis module (36). A sample channel tube (311) is provided at the center of the top of the acoustic wave propagation test chamber (31). The acoustic wave generator (32) and the acoustic wave receiver (33) are symmetrically installed on the inner wall of the acoustic wave propagation test chamber (31). When the rock sample after the NMR test falls onto the test stage (312) in the middle of the acoustic wave propagation test chamber (31), the acoustic wave generator (32) emits test acoustic waves towards the middle of the rock sample. The acoustic wave receiver (33) receives the acoustic waves propagated back from the rock sample and converts them into electrical signals and transmits them to the signal amplifier (35). The oscilloscope (34) is communicatively connected to the signal amplifier (35). The acoustic wave propagation test analysis module (36) communicates with the data output port of the oscilloscope (34) to interact with the acoustic wave signals, analyzes the collected acoustic wave signals, and calculates the second permeability value.

5. The geological core permeability testing device according to claim 4, characterized in that: The pressure test unit includes a pressure test chamber (41), a pressure simulation module (42), a pressure test container (43), a fluid medium injection device (44), a micro flow sensor (45), a chip-based pressure controller (46), and a chip-based pressure test analysis module (47). The pressure test container (43) is installed in the pressure test chamber (41). After a core sample is placed in the pressure test container (43), the pressure simulation module (42) is activated to simulate formation pressure in the pressure test chamber (41). The pressure controller (46) controls the fluid medium injection device (44) to inject a liquid medium with a set pressure at both ends of the core sample. The micro flow sensor (45) is used to monitor the flow rate of the liquid medium. The pressure test analysis module (47) is communicatively connected to the pressure controller (46) and the micro flow sensor (45), exchanges the pressure values and fluid flow rate values at both ends of the core sample, and calculates the third permeability value.

6. The geological core permeability testing device according to claim 5, characterized in that: The permeability analysis and calculation unit includes a data acquisition module (51), a data memory (52), and a data analysis computer (53). The data acquisition module (51) is communicatively connected to the data output terminals of the nuclear magnetic resonance core analyzer (22), the acoustic wave propagation test analysis module (36), and the pressure test analysis module (47). The data memory (52) is communicatively connected to the data acquisition module (51). The data analysis computer (53) is communicatively connected to the data memory (52), and calculates and outputs the geological core permeability value based on the collected first permeability value, second permeability value, and third permeability value.

7. Method for testing the permeability of geological cores, characterized in that: Using the geological core permeability test device according to claim 6 to conduct a permeability test on a core specimen, including the following steps: Step 1, select a core sample to be tested from the core library and place the core sample at the sample inlet of the sample injection unit. Step 2, place the core sample that has been cleaned and air-dried into the sample injection tube (21) of the nuclear magnetic resonance unit. The nuclear magnetic resonance core analyzer (22) conducts an NMR test on the core sample and outputs the first permeability value. Step 3, place the core sample that has completed the NMR test on the test bench (312) in the middle of the acoustic wave propagation test chamber (31). The acoustic wave propagation test unit conducts an acoustic wave propagation test on the geological core sample to obtain the second permeability value of the core sample. Step 4, place the core sample that has completed the acoustic wave propagation test into the pressure test container (43) of the pressure test unit. The pressure test unit conducts a confining pressure test on the geological core sample to obtain the third permeability value of the core sample. Step 5, the data analysis computer (53) calibrates the third permeability value using the first permeability value and the second permeability value, and outputs the calibrated geological core permeability value.

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