Geological core permeability testing device and method

Abstract

The invention discloses a geological core permeability testing device and method, and relates to the technical field of geological core physical property analysis, and the geological core permeability testing device comprises a nuclear magnetic resonance unit, a sound wave propagation testing unit, a pressure testing unit and a permeability analysis and calculation unit. According to the method, the permeability of the geological rock core can be evaluated more comprehensively by combining three different methods of NMR, sound wave propagation testing and pressure testing, the NMR and sound wave propagation testing are non-destructive methods, multiple tests can be carried out under the condition that a rock core sample is not damaged, the integrity of the sample is kept, and subsequent other analysis is facilitated. The permeability value obtained by the pressure test is calibrated according to the permeability value obtained by the NMR and sound wave propagation test, so that the accuracy of the final permeability value is improved, and errors caused by a single test method are reduced. The invention provides an efficient, accurate and environment-friendly geological core permeability testing device which is beneficial to improving the economic benefit of oil and gas field development.

Description

Technical Field

[0001] The invention relates to the technical field of geological core physical property analysis, and in particular to a geological core permeability testing device and method. Background Art

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

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

[0004] Mercury injection method calculates permeability by measuring the pore volume of the core that is infiltrated by mercury under a certain pressure. Mercury injection method is a destructive test method because it requires injecting mercury into the pores of the rock, 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 the pores of the rock can be ignored, but in fact, mercury may interact with the rock surface and affect the measurement results.

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

[0006] The differential osmotic pressure method is to place the core sample in the permeameter, apply a certain pressure difference, and measure the speed of the fluid passing through the core to calculate the permeability. This method requires the selection of appropriate fluids for testing. Different fluids may interact with the rock differently, affecting the measurement results. For rock samples with low permeability, the speed of the fluid passing through the core may be very slow, resulting in a long test time. The sample preparation needs to be very precise, and any tiny defects or cracks may cause deviations in the fluid flow path, thereby affecting the permeability measurement.

[0007] The permeability test method is to place the core sample in a permeameter, apply a certain pressure difference, measure the volume and time of the fluid passing through the core to calculate the permeability. 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] In order to solve the above technical problems, the present invention provides a geological core permeability testing device and method. The following technical solutions are adopted: A geological core permeability testing device, including a nuclear magnetic resonance unit, an acoustic wave propagation testing unit, a pressure testing unit and a permeability analysis and calculation unit; The nuclear magnetic resonance unit is used to perform NMR testing on the geological core sample to obtain a first permeability value of the core sample; The sample inlet of the acoustic wave propagation test unit is connected to the sample outlet of the nuclear magnetic resonance unit, and the acoustic wave propagation test unit is used to perform an acoustic wave propagation test on the geological core sample to obtain a second permeability value of the core sample; The pressure testing unit is used to perform a confining pressure test on the geological core sample under simulated formation pressure conditions to obtain a third permeability value of the core sample; The permeability analysis and calculation unit communicates and exchanges test results with the nuclear magnetic resonance unit, the sound wave propagation test unit and the pressure test unit respectively, and uses the first permeability value and the second permeability value to calibrate the third permeability value to output the geological core permeability value.

[0009] By adopting the above technical solution, the permeability of geological cores can be more comprehensively evaluated by combining three different methods: NMR, acoustic wave propagation testing and pressure testing. Both NMR and acoustic wave propagation testing are non-destructive methods that can be tested multiple times without damaging the core samples, maintaining the integrity of the samples and facilitating other subsequent analyses.

[0010] 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, and pressure testing simulates actual formation conditions. These multi-parameter measurements help to gain a deeper understanding of the permeability characteristics of the core.

[0011] By using the permeability values ​​obtained from NMR and acoustic wave propagation tests to calibrate the permeability values ​​obtained from pressure tests, the accuracy of the final permeability values ​​can be improved and the errors that may be caused by a single test method can be reduced.

[0012] Through automation and data integration, the time for manual operation and data processing is reduced, and the testing efficiency is improved.

[0013] The device can adapt to different types of cores and samples with different permeability ranges, and is suitable for a variety of geological exploration and development scenarios.

[0014] The permeability analysis and calculation unit conducts a comprehensive analysis of the data from different test units to ensure the uniformity and consistency of the final permeability data.

[0015] The invention provides an efficient, accurate and environmentally friendly geological core permeability testing device, which is helpful to improve the economic benefits and safety of oil and gas field development.

[0016] Optionally, it also includes a sampling unit, which includes a cleaning device and an air-drying device. The cleaning device is provided with a geological core sample inlet, the cleaning device is used to remove impurities on the surface of the core sample, and the air-drying device is used to air-dry the cleaned core sample. A sample outlet is arranged at the bottom of the sampling unit, and an electric control door is installed at the sample outlet. When the air-drying device completes the air-drying operation, the electric control door is opened, and the core sample falls into the sample inlet of the nuclear magnetic resonance unit.

[0017] By adopting the above technical solution, the cleaning device uses a non-polluting cleaning agent to gently clean the surface of the core sample to remove impurities. The cleaned core sample is placed in an air drying device to remove excess water, which can ensure the accuracy of the results of subsequent tests.

[0018] Optionally, the nuclear magnetic resonance unit includes an injection tube and a nuclear magnetic resonance rock sample analyzer, the inlet of the injection tube is connected to the outlet of the injection unit, when the electric control door is opened, the core sample falls into the sample table of the nuclear magnetic resonance rock sample analyzer through the injection tube, and the nuclear magnetic resonance rock sample analyzer performs NMR testing on the sample and outputs a first permeability value.

[0019] By adopting the above technical solution, the nuclear magnetic resonance rock sample analyzer can realize NMR testing and directly output the first permeability value.

[0020] Optionally, the sound wave propagation test unit includes a sound wave propagation test chamber, a sound wave generator, a sound wave receiver, an oscilloscope, a signal amplifier and a chip-based sound wave propagation test analysis module, wherein a sample channel tube is provided in the center of the top of the sound wave propagation test chamber, and the sound wave generator and the sound wave receiver are symmetrically installed on the inner wall of the sound wave propagation test chamber. When the rock sample after the NMR test falls into the test table in the middle of the sound wave propagation test chamber, the sound wave generator emits a test sound wave toward the middle of the rock sample, and the sound wave receiver receives the sound wave propagated back from the rock sample and converts it into an electrical signal and transmits it to the signal amplifier. The oscilloscope is communicatively connected to the signal amplifier, and the sound wave propagation test analysis module communicates with the data output port of the oscilloscope to exchange sound wave signals, analyzes the collected sound wave signals, and calculates the second permeability value.

[0021] By adopting the above technical solution, the rock sample that has completed the NMR test falls into the test table in the middle of the acoustic wave propagation test chamber through the sample channel tube. The acoustic wave generator is activated to emit test acoustic waves of a certain frequency and amplitude toward the middle of the rock sample. These acoustic waves can be pulse waves or continuous waves, depending on the test requirements and sample characteristics.

[0022] After the sound waves propagate in the rock sample, they are received by the sound wave receiver. The receiver records the time delay and amplitude change of the sound wave propagation. The sound wave receiver converts the received sound wave signal into an electrical signal, which is then transmitted to the signal amplifier for amplification and processing for subsequent analysis. The oscilloscope is connected to the signal amplifier 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 and analysis module communicates with the data output port of the oscilloscope to collect the sound wave signal data displayed by the oscilloscope. The sound wave propagation test and analysis module uses specific algorithms to process the collected sound wave signals, which may include time domain analysis, frequency domain analysis, or waveform analysis.

[0023] Optionally, the pressure testing unit includes a pressure testing chamber, a pressure simulation module, a pressure testing container, a fluid medium injection device, a micro-flow sensor, a chip-based pressure controller and a chip-based pressure testing analysis module. The pressure testing container is installed in the pressure testing chamber. When a core sample is placed in the pressure testing container, the pressure simulation module starts to simulate the formation pressure in the pressure testing chamber. The pressure controller controls the fluid medium injection device to inject liquid medium of set pressure at both ends of the core sample. The micro-flow sensor is used to monitor the flow of the liquid medium. The pressure testing analysis module is communicated with the pressure controller and the micro-flow sensor, exchanges the pressure values ​​and fluid flow values ​​at both ends of the core sample, and calculates a third permeability value.

[0024] By adopting the above technical solution, the core sample that has completed the NMR and acoustic wave propagation tests is placed in a pressure test container. The pressure test container is sealed and prepared for pressure testing. The pressure simulation module is started to simulate the formation pressure conditions in the pressure test chamber. This usually involves adjusting the temperature and pressure to the predetermined simulation values. The pressure controller activates the fluid medium injection device and starts to inject the liquid medium of the set pressure at both ends of the core sample. The injection pressure should be gradually increased to simulate the 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 into the two ends of the core sample in real time. The flow data is crucial for the subsequent permeability calculation. The pressure test analysis module communicates with the pressure controller and the micro flow sensor to collect the pressure value and fluid flow value at both ends of the core sample. Maintain the pressure for a period of time until the pressure and flow reach a stable state.

[0025] Optionally, the permeability analysis and calculation unit includes a data acquisition module, a data storage device and a data analysis computer. The data acquisition module is communicatively connected to the data output ends of the nuclear magnetic resonance rock sample analyzer, the acoustic wave propagation test analysis module and the pressure test analysis module, respectively; the data storage device is communicatively connected to the data acquisition module; and the data analysis computer is communicatively connected to the data storage device. The output geological core permeability value is calculated based on the collected first permeability value, second permeability value and third permeability value.

[0026] 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 collection module.

[0027] The geological core permeability testing method uses a geological core permeability testing device to perform permeability testing on a core sample, and includes the following steps: Step 1, selecting a core sample to be tested from a core library, and placing the core sample into a sample inlet of a sampling unit; Step 2, placing the cleaned and air-dried core sample into the sampling tube of the nuclear magnetic resonance unit, and using a nuclear magnetic resonance rock sample analyzer to perform an NMR test on the core sample to output a first permeability value; Step 3, placing the core sample that has completed the NMR test into the test bench in the middle of the acoustic wave propagation test chamber, and the acoustic wave propagation test unit performs an acoustic wave propagation test on the geological core sample to obtain a second permeability value of the core sample; Step 4, placing the core sample that has completed the acoustic wave propagation test into a pressure test container of a pressure test unit, and the pressure test unit performs a confining pressure test on the geological core sample to obtain a third permeability value of the core sample; 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.

[0028] Optionally, the formula for calculating the first permeability value is: ; in is the first permeability value, A is the NMR test proportionality constant, is the transverse relaxation time in NMR measurements, is the adjustment index used to adjust The contribution of the value to the permeability estimation is is the volume element, and n is the influence index, which determines The degree to which the integral value of the distribution affects the permeability estimation, express about The integral operation is performed on all The pore volumes of the values ​​are weighted summed.

[0029] Optionally, in step 3, the formula for calculating the second permeability value is: ; in is the second permeability value, C is the proportionality constant between the acoustic wave velocity and the permeability, is the longitudinal wave velocity of the sound wave in the rock sample, It is the correlation index between acoustic wave velocity and permeability.

[0030] Optionally, in step 4, the formula for calculating the third permeability value is: ; in 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; Calibrate the third permeability value to obtain the geological core permeability value The formula is: .

[0031] In summary, the present invention includes at least one of the following beneficial technical effects: The present invention can provide a geological core permeability testing device and method. By combining three different methods, namely NMR, acoustic wave propagation test and pressure test, the permeability of the geological core can be more comprehensively evaluated. Both NMR and acoustic wave propagation test are non-destructive methods, and multiple tests can be performed without damaging the core sample, thereby maintaining the integrity of the sample and facilitating subsequent other analyses.

[0032] The permeability values ​​obtained by NMR and acoustic wave propagation tests are used to calibrate the permeability values ​​obtained by pressure tests, thereby improving the accuracy of the final permeability values ​​and reducing the errors caused by a single test method.

[0033] The device can adapt to different types of cores and samples with different permeability ranges, and is suitable for a variety of geological exploration and development scenarios.

[0034] The permeability analysis and calculation unit conducts a comprehensive analysis of the data from different test units to ensure the uniformity and consistency of the final permeability data.

[0035] The invention provides an efficient, accurate and environmentally friendly geological core permeability testing device, which is helpful to improve the economic benefits of oil and gas field development. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 It is a schematic diagram of the component structure principle of the geological core permeability testing device of the present invention; Figure 2 This is a schematic diagram of the connection principle of the electrical components of the geological core permeability testing device of the present invention; Figure 3 It is a schematic flow chart of the geological core permeability testing method of the present invention.

[0037] Explanation of the accompanying drawings: 11. Cleaning device; 12. Air drying device; 21. Sample injection tube; 22. Nuclear magnetic resonance rock sample analyzer; 31. Sound wave propagation test chamber; 311. Sample channel tube; 312. Test bench; 32. Sound wave generator; 33. Sound wave receiver; 34. Oscilloscope; 35. Signal amplifier; 36. Sound wave propagation test 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 analysis module; 51. Data acquisition module; 52. Data storage device; 53. Data analysis computer. DETAILED DESCRIPTION

[0038] The present invention is further described in detail below in conjunction with the accompanying drawings.

[0039] The embodiments of the present invention disclose a geological core permeability testing device and method.

[0040] Reference Figure 1-Figure 3 , Embodiment 1, a geological core permeability testing device, comprising a nuclear magnetic resonance unit, an acoustic wave propagation testing unit, a pressure testing unit and a permeability analysis and calculation unit; The nuclear magnetic resonance unit is used to perform NMR testing on the geological core sample to obtain a first permeability value of the core sample; The sample inlet of the acoustic wave propagation test unit is connected to the sample outlet of the nuclear magnetic resonance unit, and the acoustic wave propagation test unit is used to perform an acoustic wave propagation test on the geological core sample to obtain a second permeability value of the core sample; The pressure testing unit is used to perform a confining pressure test on the geological core sample under simulated formation pressure conditions to obtain a third permeability value of the core sample; The permeability analysis and calculation unit communicates and exchanges test results with the nuclear magnetic resonance unit, the acoustic wave propagation test unit and the pressure test unit respectively, and uses the first permeability value and the second permeability value to calibrate the third permeability value to output the geological core permeability value.

[0041] By combining three different methods, NMR, acoustic propagation testing and pressure testing, the permeability of geological cores can be more comprehensively evaluated. Both NMR and acoustic propagation testing are non-destructive methods that can be tested multiple times without damaging the core samples, maintaining the integrity of the samples and facilitating subsequent other analyses.

[0042] 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, and pressure testing simulates actual formation conditions. These multi-parameter measurements help to gain a deeper understanding of the permeability characteristics of the core.

[0043] By using the permeability values ​​obtained from NMR and acoustic wave propagation tests to calibrate the permeability values ​​obtained from pressure tests, the accuracy of the final permeability values ​​can be improved and the errors that may be caused by a single test method can be reduced.

[0044] Through automation and data integration, the time for manual operation and data processing is reduced, and the testing efficiency is improved.

[0045] The device can adapt to different types of cores and samples with different permeability ranges, and is suitable for a variety of geological exploration and development scenarios.

[0046] The permeability analysis and calculation unit conducts a comprehensive analysis of the data from different test units to ensure the uniformity and consistency of the final permeability data.

[0047] The invention provides an efficient, accurate and environmentally friendly geological core permeability testing device, which is helpful to improve the economic benefits and safety of oil and gas field development.

[0048] Embodiment 2 also includes a sampling unit, which includes a cleaning device 11 and an air-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 air-drying device 12 is used to air-dry the cleaned core sample. A sample outlet is provided at the bottom of the sampling unit, and an electric control door is installed at the sample outlet. When the air-drying device 12 completes the air-drying operation, the electric control door is opened, and the core sample falls into the sample inlet of the nuclear magnetic resonance unit.

[0049] The cleaning device 11 uses a non-polluting cleaning agent to gently clean the surface of the core sample to remove impurities. The cleaned core sample is placed in the air drying device 12 to remove excess water, which can ensure the accuracy of the results of subsequent tests.

[0050] Embodiment 3, the nuclear magnetic resonance unit includes a sampling tube 21 and a nuclear magnetic resonance rock sample analyzer 22, the inlet of the sampling tube 21 is connected to the sample outlet of the sampling unit, when the electric control door is opened, the core sample falls into the sample table of the nuclear magnetic resonance rock sample analyzer 22 through the sampling tube 21, and the nuclear magnetic resonance rock sample analyzer 22 performs NMR test on the sample and outputs a first permeability value.

[0051] The nuclear magnetic resonance rock sample analyzer 22 can implement NMR testing and directly output a first permeability value.

[0052] Embodiment 4, the sound wave propagation test unit includes a sound wave propagation test chamber 31, a sound wave generator 32, a sound wave receiver 33, an oscilloscope 34, a signal amplifier 35 and a chip-based sound wave propagation test analysis module 36. A sample channel tube 311 is provided in the center of the top of the sound wave propagation test chamber 31. The sound wave generator 32 and the sound wave receiver 33 are symmetrically installed on the inner wall of the sound wave propagation test chamber 31. When the rock sample after the NMR test falls into the test table 312 in the middle of the sound wave propagation test chamber 31, the sound wave generator 32 emits a test sound wave toward the middle of the rock sample, the sound wave receiver 33 receives the sound wave propagated back from the rock sample and converts it into an electrical signal and transmits it to the signal amplifier 35. The oscilloscope 34 is connected to the signal amplifier 35 for communication. The sound wave propagation test analysis module 36 communicates with the data output port of the oscilloscope 34 to exchange sound wave signals, analyzes the collected sound wave signals, and calculates the second permeability value.

[0053] The rock sample that has completed the NMR test falls into the test table 312 in the middle of the acoustic wave propagation test chamber 31 through the sample channel tube 311. The acoustic wave generator 32 is activated to emit test acoustic waves of a certain frequency and amplitude toward the middle of the rock sample. These acoustic waves can be pulse waves or continuous waves, depending on the test requirements and sample characteristics.

[0054] After the sound wave propagates in 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 for subsequent analysis. The oscilloscope 34 is connected to the signal amplifier 35 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 uses specific algorithms to process the collected sound wave signals. These algorithms may include time domain analysis, frequency domain analysis or waveform analysis.

[0055] Embodiment 5, the pressure testing unit includes a pressure testing chamber 41, a pressure simulation module 42, a pressure testing container 43, a fluid medium injection device 44, a micro-flow sensor 45, a chip-based pressure controller 46 and a chip-based pressure testing analysis module 47. The pressure testing container 43 is installed in the pressure testing chamber 41. When a core sample is placed in the pressure testing container 43, the pressure simulation module 42 starts to simulate the formation pressure in the pressure testing chamber 41. The pressure controller 46 controls the fluid medium injection device 44 to inject liquid medium of 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 testing analysis module 47 is communicated with the pressure controller 46 and the micro-flow sensor 45, exchanges the pressure values ​​and fluid flow values ​​at both ends of the core sample, and calculates the third permeability value.

[0056] The core sample that has completed the NMR and acoustic wave propagation tests is placed in the pressure test container 43. The pressure test container 43 is sealed and prepared for pressure testing. The pressure simulation module 42 is started to simulate the formation pressure conditions in the pressure test chamber 41. This usually involves adjusting the temperature and pressure to predetermined simulation values. The pressure controller 46 activates the fluid medium injection device 44 and begins to inject the liquid medium of the set pressure at both ends of the core sample. The injection pressure should be gradually increased to simulate the actual formation pressure conditions. The fluid medium can be saturated brine, kerosene or light oil, etc. The micro flow sensor 45 monitors and records the flow rate of the liquid medium injected into the two ends of the core sample in real time. The flow 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 value and fluid flow value at both ends of the core sample. Maintain the pressure for a period of time until the pressure and flow reach a stable state.

[0057] Embodiment 6, the permeability analysis and calculation unit includes a data acquisition module 51, a data storage device 52 and a data analysis computer 53, the data acquisition module 51 is respectively communicated with the data output ends of the nuclear magnetic resonance rock sample analyzer 22, the acoustic wave propagation test analysis module 36 and the pressure test analysis module 47, the data storage device 52 is communicated with the data acquisition module 51, and the data analysis computer 53 is communicated with the data storage device 52, and the permeability value of the geological core is calculated and output based on the collected first permeability value, second permeability value and third permeability value.

[0058] The data analysis computer 53 can calculate and output the geological core permeability value based on the three permeability values ​​collected by the data collection module 51 .

[0059] Embodiment 7, geological core permeability testing method, using geological core permeability testing device to test the permeability of the core sample, comprising the following steps: Step 1, selecting a core sample to be tested from a core library, and placing the core sample into a sample inlet of a sampling unit; Step 2, placing the cleaned and air-dried core sample into the sample inlet tube 21 of the nuclear magnetic resonance unit, and the nuclear magnetic resonance rock sample analyzer 22 performs NMR testing on the core sample to output a first permeability value; Step 3, placing the core sample that has completed the NMR test into the test table 312 in the middle of the acoustic wave propagation test chamber 31, and the acoustic wave propagation test unit performs an acoustic wave propagation test on the geological core sample to obtain a second permeability value of the core sample; Step 4, placing the core sample that has completed the acoustic wave propagation test into the pressure test container 43 of the pressure test unit, and the pressure test unit performs a confining pressure test on the geological core sample to obtain a third permeability value of the core sample; 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.

[0060] In Example 8, the formula for calculating the first permeability value is: ; in is the first permeability value, A is the NMR test proportionality constant, is the transverse relaxation time in NMR measurements, is the adjustment index used to adjust The contribution of the value to the permeability estimation is is the volume element, and n is the influence index, which determines The degree to which the integral value of the distribution affects the permeability estimation, express about The integral operation is performed on all The pore volumes of the values ​​are weighted summed.

[0061] In Example 9, in step 3, the formula for calculating the second permeability value is: ; in is the second permeability value, C is the proportionality constant between the acoustic wave velocity and the permeability, is the longitudinal wave velocity of the sound wave in the rock sample, It is the correlation index between acoustic wave velocity and permeability.

[0062] In Example 10, in step 4, the formula for calculating the third permeability value is: ; in 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; Calibrate the third permeability value to obtain the geological core permeability value The formula is: .

[0063] The above are all preferred embodiments of the present invention, and are not intended to limit the protection scope of the present invention. Therefore, any equivalent changes made based on the structure, shape, and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. Geological core permeability testing device, characterized by: 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 testing on the geological core sample to obtain a first permeability value of the core sample; The sample inlet of the acoustic wave propagation test unit is connected to the sample outlet of the nuclear magnetic resonance unit, and the acoustic wave propagation test unit is used to perform an acoustic wave propagation test on the geological core sample to obtain a second permeability value of the core sample; The pressure testing unit is used to perform a confining pressure test on the geological core sample under simulated formation pressure conditions to obtain a third permeability value of the core sample; The permeability analysis and calculation unit communicates and exchanges test results with the nuclear magnetic resonance unit, the sound wave propagation test unit and the pressure test unit respectively, and uses the first permeability value and the second permeability value to calibrate the third permeability value to output the geological core permeability value.

2. The geological core permeability testing device according to claim 1, characterized in that: The invention also comprises a sample introduction unit, wherein the sample introduction unit comprises a cleaning device (11) and an air drying device (12), wherein 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, and the air drying device (12) is used to air dry the cleaned core sample. A sample outlet is provided at the bottom of the sample introduction unit, and an electric control door is installed at the sample outlet. When the air drying device (12) completes the air 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, characterized in that: The nuclear magnetic resonance unit comprises 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 sample outlet of the sample injection unit; when the electric control door is opened, the core sample passes through the sample injection tube (21) and falls into the sample table of the nuclear magnetic resonance rock sample analyzer (22); the nuclear magnetic resonance rock sample analyzer (22) performs an NMR test on the sample and outputs a first permeability value.

4. The geological core permeability testing device according to claim 3, characterized in that: The sound wave propagation test unit comprises a sound wave propagation test chamber (31), a sound wave generator (32), a sound wave receiver (33), an oscilloscope (34), a signal amplifier (35), and a chip-based sound wave propagation test analysis module (36). A sample channel tube (311) is provided at the center of the top of the sound wave propagation test chamber (31). The sound wave generator (32) and the sound wave receiver (33) are symmetrically mounted on the inner wall of the sound wave propagation test chamber (31). When the rock sample after the NMR test falls into the test table (312) in the middle of the sound wave propagation test chamber (31), the sound wave generator (32) emits a test sound wave toward the middle of the rock sample. The sound wave receiver (33) receives the sound wave propagated back from the rock sample and converts it into an electrical signal for transmission to the signal amplifier (35). The oscilloscope (34) is connected to the signal amplifier (35) for communication. The sound wave propagation test analysis module (36) communicates with the data output port of the oscilloscope (34) to exchange sound wave signals, analyzes the collected sound wave signals, and calculates a second permeability value.

5. The geological core permeability testing device according to claim 4, characterized in that: The pressure test unit comprises 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). When a core sample is placed in the pressure test container (43), the pressure simulation module (42) starts 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 of a set pressure at both ends of the core sample. The micro flow sensor (45) is used to monitor the flow of the liquid medium. The pressure test analysis module (47) is connected to the pressure controller (46) and the micro flow sensor (45) in communication, exchanges the pressure values ​​and fluid flow values ​​at both ends of the core sample, and calculates a third permeability value.

6. The geological core permeability testing device according to claim 5, characterized in that: The permeability analysis and calculation unit comprises a data acquisition module (51), a data storage device (52) and a data analysis computer (53); the data acquisition module (51) is respectively connected in communication with the data output ends of the nuclear magnetic resonance rock sample analyzer (22), the acoustic wave propagation test analysis module (36) and the pressure test analysis module (47); the data storage device (52) is connected in communication with the data acquisition module (51); the data analysis computer (53) is connected in communication with the data storage device (52); and the permeability value of the geological core is calculated and output based on the collected first permeability value, second permeability value and third permeability value.

7. A method for testing the permeability of geological cores, characterized in that: The permeability test device for geological cores according to claim 6 is used to test the permeability of core samples, comprising the following steps: Step 1, selecting a core sample to be tested from a core library, and placing the core sample into a sample inlet of a sampling unit; Step 2, placing the cleaned and air-dried core sample into the sample inlet tube (21) of the nuclear magnetic resonance unit, and using a nuclear magnetic resonance rock sample analyzer (22) to perform an NMR test on the core sample and output a first permeability value; Step 3, placing the core sample that has completed the NMR test into the test table (312) in the middle of the acoustic wave propagation test chamber (31), and the acoustic wave propagation test unit performs an acoustic wave propagation test on the geological core sample to obtain a second permeability value of the core sample; Step 4, placing the core sample that has completed the acoustic wave propagation test into a pressure test container (43) of a pressure test unit, and the pressure test unit performs a confining pressure test on the geological core sample to obtain a third permeability value of the core sample; 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.

8. The method for testing the geological core permeability according to claim 7, characterized in that: In step 2, the formula for calculating the first permeability value is: ； in is the first permeability value, A is the NMR test proportionality constant, is the transverse relaxation time in NMR measurements, is the adjustment index used to adjust The contribution of the value to the permeability estimation is is the volume element, and n is the influence index, which determines The degree to which the integral value of the distribution affects the permeability estimation, express about The integral operation.

9. The method for testing the geological core permeability according to claim 8, characterized in that: In step 3, the formula for calculating the second permeability value is: ； in is the second permeability value, C is the proportionality constant between the acoustic wave velocity and the permeability, is the longitudinal velocity of the sound wave in the rock sample, It is the correlation index between acoustic wave velocity and permeability.

10. The geological core permeability testing method according to claim 9, characterized in that: In step 4, the formula for calculating the third permeability value is: ； in 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; Calibrate the third permeability value to obtain the geological core permeability value The formula is: 。

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