Natural gas hydrate stratum ultrasonic response testing method and response clamping device

Abstract

The invention provides a natural gas hydrate stratum ultrasonic response test method and a response clamping device. A first kettle cover and a second kettle cover in the ultrasonic response clamping device are both mounted on a platform; the second kettle cover is provided with a pressure sensing module and an ultrasonic probe; the first kettle cover is provided with a supporting structure; the gas injection device is connected with the kettle body to inject gas into the kettle body, and the pressure tester is mounted on the kettle body to detect the gas pressure in the kettle body; the test method comprises the following steps: step S10, loading a natural gas hydrate sample into a sample cavity; step S20, injecting gas into the kettle body by a gas injection device so as to regulate and control the gas pressure in the kettle body, and detecting the gas pressure in the kettle body by a pressure tester; s30, the ultrasonic probe conducts ultrasonic testing on the natural gas hydrate sample. The technical problem that natural gas hydrate reservoir site data are difficult to obtain is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of natural gas hydrate formation exploration, and particularly to a method for testing ultrasonic response of natural gas hydrate formation and a response clamping device. Background Art

[0002] Currently, ultrasonic response testing mainly focuses on conventional cement stone, with a single ultrasonic response and unable to comprehensively and accurately measure material data. Natural gas hydrate formations are generally located in deep sea areas, and it is difficult to obtain on-site data of natural gas hydrate reservoirs. Natural gas hydrates will rapidly deteriorate under normal pressure above the ground, making it difficult to conduct tests. Summary of the Invention

[0003] The purpose of the present invention is to provide a method for testing ultrasonic response of natural gas hydrate formation and a response clamping device to solve the technical problem of difficult acquisition of on-site data of natural gas hydrate reservoirs.

[0004] The above object of the present invention can be achieved by the following technical solutions:

[0005] The present invention provides a method for testing ultrasonic response of natural gas hydrate formation. The ultrasonic response clamping device used includes: a kettle body, an ultrasonic probe, a pressure sensing module, a pressure tester, and an air injection device. The kettle body includes a platform, a first kettle cover and a second kettle cover arranged oppositely. Both the first kettle cover and the second kettle cover are installed on the platform, and a sample cavity is arranged between the first kettle cover and the second kettle cover;

[0006] The second kettle cover is provided with a plurality of the pressure sensing modules and the ultrasonic probe; the second kettle cover is provided with a support structure;

[0007] The air injection device is connected to the kettle body to inject gas into the kettle body, and the pressure tester is installed on the kettle body to detect the air pressure in the kettle body;

[0008] The method for testing ultrasonic response of natural gas hydrate formation includes:

[0009] Step S10, loading a natural gas hydrate sample into the sample cavity. The ultrasonic probe and the pressure sensing module on the second kettle cover are both in contact with the side surface of the natural gas hydrate sample, the support structure on the first kettle cover is in contact with the other side surface of the natural gas hydrate sample, and a spacing cavity is arranged between the inner wall of the first kettle cover and the side wall of the natural gas hydrate sample and between the inner wall of the second kettle cover and the side wall of the natural gas hydrate sample;

[0010] Step S20, the air injection device injects gas into the kettle body to regulate the air pressure in the kettle body, and the pressure tester detects the air pressure in the kettle body;

[0011] Step S30, the ultrasonic probe performs ultrasonic testing on the natural gas hydrate sample.

[0012] In a preferred embodiment, the ultrasonic response clamping device includes a temperature tester, and the temperature tester is installed on the kettle body to detect the temperature inside the kettle body.

[0013] In a preferred embodiment, the first kettle cover is provided with a plurality of first kettle cover through holes, and the support structure includes the ultrasonic probe connected to the first kettle cover through holes.

[0014] In a preferred embodiment, a plurality of the ultrasonic probes are connected to the second kettle cover, and the end faces of the plurality of ultrasonic probes on the second kettle cover and the pressure sensing module located in the sample cavity are in the same plane.

[0015] In a preferred embodiment, the second kettle cover is provided with a plurality of second kettle cover through holes, both the pressure sensing module and the ultrasonic probe are connected to the second kettle cover through holes, and both the first kettle cover through holes and the second kettle cover through holes are threaded holes; by rotating the ultrasonic probe to adjust the position of the end face of the ultrasonic probe located in the sample cavity, and by rotating the pressure sensing module to adjust the position of the end face of the pressure sensing module located in the sample cavity.

[0016] In a preferred embodiment, at least one of the first kettle cover and the second kettle cover is detachably installed on the platform.

[0017] In a preferred embodiment, the first kettle cover is detachably installed on the platform; and, the platform is provided with an installation groove; the bottom of the first kettle cover is provided with a vertical protrusion and a horizontal protrusion, the vertical protrusion can extend into the installation groove, and the horizontal protrusion is arranged on the inner wall of the first kettle cover and can abut against the top surface of the platform.

[0018] In a preferred embodiment, the step S30 includes: collecting the ultrasonic waveform of the natural gas hydrate sample through the ultrasonic probe; establishing the correlation relationship between the formation characteristic parameters, the ultrasonic frequency and the ultrasonic wave velocity; and calculating the unknown physical property parameters of the natural gas hydrate sample according to the correlation relationship and the known actual formation physical property parameters.

[0019] In a preferred embodiment, the gas injection device injects inert gas into the kettle body to perform pressure boosting and pressure maintaining.

[0020] The present invention provides an ultrasonic response clamping device for the above-mentioned ultrasonic response test method for natural gas hydrate formation. The ultrasonic response clamping device includes: a kettle body, an ultrasonic probe, a pressure sensing module, a pressure tester, and an air injection device. The kettle body includes a platform, a first kettle lid and a second kettle lid arranged oppositely. The first kettle lid and the second kettle lid are both installed on the platform, and a sample chamber is arranged between the first kettle lid and the second kettle lid.

[0021] The second kettle lid is provided with a plurality of through holes of the second kettle lid. At least one of the through holes of the second kettle lid is connected to the pressure sensing module, and at least one of the through holes of the second kettle lid is connected to the ultrasonic probe; the first kettle lid is provided with a support structure.

[0022] The air injection device is connected to the kettle body to inject gas into the kettle body, and the pressure tester is installed on the kettle body to detect the air pressure in the kettle body.

[0023] The characteristics and advantages of the present invention are as follows:

[0024] The ultrasonic response test method provided by the present invention is aimed at the test of the physical property parameters of natural gas hydrate formation. The air injection device injects gas into the kettle body and monitors it through the pressure tester, so as to control the air pressure in the kettle body. On the one hand, it simulates the actual pressure environment of natural gas hydrate formation, and on the other hand, the gas in the spacing chamber applies confining pressure to the natural gas hydrate sample to prevent the natural gas hydrate sample from deteriorating during the test; the support structure and the pressure sensing module apply pressure to the natural gas hydrate sample from both sides to keep the position of the sample stable. The ultrasonic probe emits ultrasonic waves to the natural gas hydrate sample and receives the reflected sound waves. Since both the ultrasonic probe and the pressure sensing module are in contact with the natural gas hydrate sample, the pressures of the two are roughly equal, which is beneficial to processing the sound waves received by the ultrasonic probe and ensures the accuracy of the test data, solving the problem of difficult acquisition of on-site data of natural gas hydrate reservoirs. Description of the Drawings

[0025] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0026] Figure 1 It is a schematic diagram of the ultrasonic response test method for natural gas hydrate formation provided by the present invention;

[0027] Figure 2 It is a schematic structural diagram of the ultrasonic response clamping device provided by the present invention;

[0028] Figure 3 Schematic diagram of the structure of the platform in the ultrasonic response clamping device provided by the present invention;

[0029] Figure 4 Schematic diagram of the structure of the first kettle cover in the ultrasonic response clamping device provided by the present invention;

[0030] Figure 5 Schematic diagram of the structure of the second kettle cover in the ultrasonic response clamping device provided by the present invention.

[0031] Explanation of the reference numerals in the attached drawings:

[0032] 1. Natural gas hydrate sample;

[0033] 100. Kettle body; 101. Sample cavity; 102. Spacing cavity;

[0034] 2. Second kettle cover; 21. Second kettle cover through hole

[0035] 3. First kettle cover; 31. First kettle cover through hole; 32. Vertical protrusion; 33. Horizontal protrusion;

[0036] 30. Support structure;

[0037] 4. Pressure sensing module; 41. Ultrasonic tester;

[0038] 5. Ultrasonic probe; 51. Pressure testing device;

[0039] 6. Gas injection valve; 61. Nitrogen gas cylinder;

[0040] 7. Safety relief valve;

[0041] 8. Temperature tester; 9. Pressure tester; 91. Controller;

[0042] 10. Platform; 11. Installation groove. Specific implementation manners

[0043] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0044] Solution 1

[0045] The present invention provides a method for testing the ultrasonic response of a natural gas hydrate formation, as Figures 2 - 5As shown in the figure, the ultrasonic response clamping device adopted includes: a kettle body 100, an ultrasonic probe 5, a pressure sensing module 4, a pressure tester 9, and an air injection device. The kettle body 100 includes a platform 10, a first kettle cover 3 and a second kettle cover 2 which are oppositely arranged. The first kettle cover 3 and the second kettle cover 2 are both installed on the platform 10, and a sample chamber 101 is arranged between the first kettle cover 3 and the second kettle cover 2; the second kettle cover 2 is provided with a pressure sensing module 4 and an ultrasonic probe 5; the first kettle cover 3 is provided with a support structure 30; the air injection device is connected to the kettle body 100 to inject gas into the kettle body 100, and the pressure tester 9 is installed on the kettle body 100 to detect the air pressure in the kettle body 100; as Figure 1 shown, the ultrasonic response test method for a natural gas hydrate formation includes: Step S10, loading a natural gas hydrate sample 1 into the sample chamber 101. The ultrasonic probe 5 and the pressure sensing module 4 on the second kettle cover 2 are both in contact with the side surface of the natural gas hydrate sample 1, and the support structure 30 on the first kettle cover 3 is in contact with the other side surface of the natural gas hydrate sample 1. And, as Figure 1 shown, a spacing chamber 102 is provided between the inner wall of the first kettle cover 3 and the side wall of the natural gas hydrate sample 1 and between the inner wall of the second kettle cover 2 and the side wall of the natural gas hydrate sample 1; Step S20, the air injection device injects gas into the kettle body 100 to regulate the air pressure in the kettle body 100, and the pressure tester 9 detects the air pressure in the kettle body 100; Step S30, the ultrasonic probe 5 performs an ultrasonic test on the natural gas hydrate sample 1.

[0046] The ultrasonic response test method provided by the present invention is for testing the physical property parameters of a natural gas hydrate formation. The air injection device injects gas into the kettle body 100 and monitors it through the pressure tester 9, so as to control the air pressure in the kettle body 100. On the one hand, it simulates the actual pressure environment of the natural gas hydrate formation, and on the other hand, the gas in the spacing chamber 102 exerts confining pressure on the natural gas hydrate sample 1 to prevent the natural gas hydrate sample 1 from deteriorating during the test; the support structure 30 and the pressure sensing module 4 apply pressure to the natural gas hydrate sample 1 from both sides to keep the position of the sample stable. The ultrasonic probe 5 emits ultrasonic waves to the natural gas hydrate sample 1 and receives the reflected sound waves. Since both the ultrasonic probe 5 and the pressure sensing module 4 are in contact with the natural gas hydrate sample 1, the pressures of the two are roughly equal, which is beneficial to processing the sound waves received by the ultrasonic probe 5 and ensures the accuracy of the test data, solving the problem of difficult acquisition of on-site data of natural gas hydrate reservoirs.

[0047] As Figure 2As shown, the ultrasonic response clamping device includes a temperature tester 8. The temperature tester 8 is installed on the kettle body 100 to detect the temperature inside the kettle body 100, so as to monitor the temperature inside the kettle body 100. In one embodiment, a cold water circulation water bath is arranged outside the kettle body 100, or the kettle body 100 is placed in a cold storage to control the temperature inside the kettle body 100, realizing stable control of temperature and pressure, and ensuring the stability during the test of the natural gas hydrate sample 1.

[0048] In one embodiment, the first kettle cover 3 is provided with a plurality of first kettle cover through holes 31, such as Figure 2 and Figure 4 shown, the support structure 30 includes an ultrasonic probe 5 connected to the first kettle cover through hole 31. The ultrasonic probe 5 on the first kettle cover 3 not only emits and receives ultrasonic waves, but also serves as the support structure 30, and cooperates with the ultrasonic probe 5 and the pressure sensing module 4 on the second kettle cover 2 to fix and press the natural gas hydrate sample 1.

[0049] The second kettle cover 2 is provided with a plurality of second kettle cover through holes 21. At least one second kettle cover through hole 21 is connected to a pressure sensing module 4, and at least one second kettle cover through hole 21 is connected to an ultrasonic probe 5.

[0050] Furthermore, a plurality of ultrasonic probes 5 are connected to the second kettle cover 2, such as Figure 2 and Figure 5 shown. The end faces of the plurality of ultrasonic probes 5 and the pressure sensing module 4 on the second kettle cover 2 located inside the sample cavity 101 are in the same plane, so as to ensure that the ultrasonic probes 5 and the pressure sensing module 4 uniformly press the natural gas hydrate sample 1. The cooperation of the plurality of ultrasonic probes 5 realizes multi-directional measurement of material data, and the test data is more accurate and comprehensive.

[0051] In one embodiment, both the first kettle cover through hole 31 and the second kettle cover through hole 21 are threaded holes. The ultrasonic probe 5 and the pressure sensing module 4 are installed on the first kettle cover 3 and the second kettle cover 2 in a threaded connection manner. By rotating the ultrasonic probe 5, the position of the end face of the ultrasonic probe 5 located inside the sample cavity 101 is adjusted. By rotating the pressure sensing module 4, the position of the end face of the pressure sensing module 4 located inside the sample cavity 101 is adjusted, so that the end faces of the ultrasonic probe 5 and the pressure sensing module 4 located inside the sample cavity 101 are in the same plane.

[0052] In one embodiment, at least one of the first kettle cover 3 and the second kettle cover 2 is detachably installed on the platform 10. After removing at least one of the first kettle cover 3 and the second kettle cover 2, it is convenient to load the natural gas hydrate under pressure into the kettle body 100.

[0053] Such as Figures 2 - 4As shown, the first kettle cover 3 is detachably mounted on the platform 10; and, the platform 10 is provided with a mounting groove 11; the bottom of the first kettle cover 3 is provided with a vertical protrusion 32 and a horizontal protrusion 33. The vertical protrusion 32 can extend into the mounting groove 11, and the horizontal protrusion 33 is arranged on the inner wall of the first kettle cover 3 and can abut against the top surface of the platform 10. By the cooperation of the vertical protrusion 32 and the mounting groove 11, and the cooperation of the horizontal protrusion 33 and the top surface of the platform 10, it is beneficial to make the position of the first kettle cover 3 on the platform 10 more accurate and stable, and it is convenient for disassembly. As Figure 2 , Figure 3 and Figure 5 shown, the second kettle cover 2 can also adopt a structure similar to that of the first kettle cover 3 to be connected to the platform 10, which will not be elaborated here.

[0054] In an embodiment, step S30 includes: collecting the ultrasonic waveform of the natural gas hydrate sample 1 through the ultrasonic probe 5; establishing the correlation relationship between the formation characteristic parameters, ultrasonic frequency and ultrasonic wave velocity; and calculating the unknown physical property parameters of the natural gas hydrate sample 1 according to the correlation relationship and the known actual formation physical property parameters. By adopting the ultrasonic response method to establish the correlation relationship between the physical properties of the hydrate reservoir and the ultrasonic response parameters, on this basis, the differences in ultrasonic responses before and after the transformation of the hydrate reservoir can be compared, the effect of reservoir transformation can be evaluated, which provides effective support for the development of the main business and has important significance for the transformation of the hydrate reservoir. The above establishment of the correlation relationship between the formation characteristic parameters, ultrasonic frequency and ultrasonic wave velocity includes: based on the ultrasonic response, reading the ultrasonic velocity, and combining the physical properties of the measured velocity sample, drawing the correlation fitting curve of the velocity and physical properties.

[0055] The above establishment of the correlation relationship may include: conducting ultrasonic velocity tests on the hydrate formation, establishing the correlation relationship between the formation characteristics, ultrasonic frequency and ultrasonic wave velocity, analyzing the influence laws of the formation physical property parameters, ultrasonic frequency, sample morphology and its size on the acoustic wave velocity, drawing the relationship curve between the physical property parameters of the hydrate formation and the acoustic wave velocity, and establishing the fitting relationship formula.

[0056] In an embodiment, the gas injection device injects inert gas into the kettle body 100 to increase the pressure and maintain the pressure, so as to realize the actual pressure environment of the natural gas hydrate formation in the kettle body 100 and ensure the accuracy of the test. Specifically, the inert gas may include nitrogen, etc. Specifically, the gas injection device includes an injection valve 6, a booster pump (not shown in the figure) and a nitrogen gas cylinder 61. The kettle body 100 is connected with a safety relief valve 7.

[0057] As Figure 2As shown in the figure, the ultrasonic response clamping device includes an ultrasonic tester 41, a pressure testing device 51 and a controller 91. The ultrasonic probe 5 is electrically connected to the ultrasonic tester 41, the pressure sensing module 4 is electrically connected to the pressure testing device 51, and the temperature tester 8 and the pressure tester 9 are both electrically connected to the controller 91.

[0058] The specific operation steps of the ultrasonic response testing method for natural gas hydrate formation provided by the present invention include:

[0059] (1) Install 3 groups of ultrasonic probes 5 and pressure sensing modules 4 in the corresponding threaded holes. The threaded holes at the positions where no testing is to be carried out are blocked with spare threaded nails to ensure that the surface of the pressure sensing module 4 and the surface of the ultrasonic probe 5 are on the same plane. Vaseline needs to be applied to the surface of the ultrasonic probe 5; install the temperature tester 8, the pressure tester 9 and the gas injection valve 6. One side of the gas injection valve 6 is connected to the autoclave body 100, and the other side is successively connected to the booster pump and the nitrogen gas cylinder 61; after applying vaseline to the autoclave cover seal ring, install it on the autoclave body 100.

[0060] (2) Air tightness detection: Open the gas cylinder valve, use the booster gas to pressurize nitrogen, then open the gas injection valve 6, inject nitrogen into the autoclave body 100, detect the air tightness of all joints, and the leaking parts need to be further processed. During the subsequent experiment process, the detection of air tightness still needs to be noted.

[0061] (3) Place the specimen: Close the gas injection valve 6, open the safety relief valve 7, slowly release the nitrogen in the autoclave body 100, then open the first autoclave cover 3 on the side without the pressure sensing gasket. After polishing the surface of the natural gas hydrate specimen 1 smoothly, place it inside the autoclave body 100. The specimen is in contact with the ultrasonic probe 5 and the pressure sensing module 4 on the second autoclave cover 2 at the same time. Install the first autoclave cover 3 and rotate the ultrasonic probe 5 on the first autoclave cover 3 to ensure that the ultrasonic probe 5 on the first autoclave cover 3 is in close contact with the specimen surface.

[0062] (4) Inject gas and pressurize: Close the safety relief valve 7, open the gas injection valve 6, and monitor the temperature and pressure changes in the autoclave body 100 in real time until the experimental design parameters are reached.

[0063] (5) Ultrasonic testing: Connect the power supply of the ultrasonic tester 41, place one end of a group of transducers in the transmitting array and the receiving array respectively, set the specimen length and the inherent acoustic wave time of the transducer combination on the ultrasonic tester 41, eliminate interference, operate the ultrasonic tester 41, collect the ultrasonic waveform under the conditions of this natural gas hydrate specimen 1, adjust the gain of the ultrasonic tester 41, find the first wave, and read parameters such as the first wave velocity and the first wave amplitude.

[0064] (6) Data analysis: Analyze the influence laws of formation physical property parameters, ultrasonic frequency, specimen morphology and its size on the acoustic wave velocity, draw the relationship curves between the above parameters and the acoustic wave velocity, and establish a fitting relationship formula;

[0065] (7) According to the correlation relationship and the known actual formation physical property parameters, other physical property parameters of the natural gas hydrate formation can be calculated.

[0066] Scheme Two

[0067] The present invention provides an ultrasonic response clamping device for the ultrasonic response test method of the above-mentioned natural gas hydrate formation, as Figures 2 - 5 shown. The ultrasonic response clamping device includes: a kettle body 100, an ultrasonic probe 5, a pressure sensing module 4, a pressure tester 9 and an air injection device. The kettle body 100 includes a platform 10, a first kettle cover 3 and a second kettle cover 2 which are oppositely arranged. The first kettle cover 3 and the second kettle cover 2 are both installed on the platform 10, and a specimen cavity 101 is arranged between the first kettle cover 3 and the second kettle cover 2; the second kettle cover 2 is provided with a plurality of second kettle cover through holes 21, at least one second kettle cover through hole 21 is connected to the pressure sensing module 4, and at least one second kettle cover through hole 21 is connected to the ultrasonic probe 5; the first kettle cover 3 is provided with a support structure 30; the air injection device is connected to the kettle body 100 to inject gas into the kettle body 100, and the pressure tester 9 is installed on the kettle body 100 to detect the air pressure in the kettle body 100. This ultrasonic response clamping device has all or at least part of the features and beneficial effects of the above test method, which will not be elaborated here.

[0068] The ultrasonic response clamping device provided by the present invention is mainly aimed at hydrate reservoirs. Considering the difficulties in obtaining material data of hydrate reservoirs and problems such as collapse and sand production during the drilling and production process of hydrate reservoirs, formation physical properties are obtained through the ultrasonic response method, and the reservoir changes can be analyzed in real time. With the goal of obtaining material data of hydrate reservoirs, tests can be realized before and after the transformation of hydrate reservoirs. Moreover, it can simultaneously meet the tests of conventional formations, and ultrasonic determination of material data can be carried out, with a wide range of applications.

[0069] The above are only several embodiments of the present invention. Those skilled in the art can make various changes or modifications to the embodiments of the present invention without departing from the spirit and scope of the present invention based on the content disclosed in the application documents.

Claims

1. A method for testing the ultrasonic response of a natural gas hydrate formation, characterized in that, the ultrasonic response clamping device used includes: a kettle body, an ultrasonic probe, a pressure sensing module, a pressure tester, and an air injection device. The kettle body includes a platform, a first kettle cover and a second kettle cover arranged oppositely. The first kettle cover and the second kettle cover are both installed on the platform, and a sample cavity is arranged between the first kettle cover and the second kettle cover; the second kettle cover is provided with the pressure sensing module and the ultrasonic probe; the first kettle cover is provided with a support structure; the air injection device is connected to the kettle body to inject gas into the kettle body, and the pressure tester is installed on the kettle body to detect the air pressure in the kettle body; the method for testing the ultrasonic response of the natural gas hydrate formation includes: Step S10, loading a natural gas hydrate sample into the sample cavity. The ultrasonic probe and the pressure sensing module on the second kettle cover are both in contact with the side surface of the natural gas hydrate sample, and the support structure on the first kettle cover is in contact with the other side surface of the natural gas hydrate sample. Moreover, a spacing cavity is arranged between the inner wall of the first kettle cover and the side wall of the natural gas hydrate sample and between the inner wall of the second kettle cover and the side wall of the natural gas hydrate sample; Step S20, the air injection device injects gas into the kettle body to regulate the air pressure in the kettle body, and the pressure tester detects the air pressure in the kettle body; Step S30, the ultrasonic probe performs ultrasonic testing on the natural gas hydrate sample.

2. The method for testing the ultrasonic response of a natural gas hydrate formation according to claim 1, characterized in that, the ultrasonic response clamping device includes a temperature tester, and the temperature tester is installed on the kettle body to detect the temperature in the kettle body.

3. The method for testing the ultrasonic response of a natural gas hydrate formation according to claim 2, characterized in that, the first kettle cover is provided with a plurality of first kettle cover through holes, and the support structure includes the ultrasonic probe connected to the first kettle cover through holes.

4. The method for testing the ultrasonic response of a natural gas hydrate formation according to claim 3, characterized in that, a plurality of the ultrasonic probes are connected to the second kettle cover, and the end faces of the plurality of ultrasonic probes and the pressure sensing module on the second kettle cover located in the sample cavity are in the same plane.

5. The method for testing the ultrasonic response of a natural gas hydrate formation according to claim 3, characterized in that, the second kettle cover is provided with a plurality of second kettle cover through holes, and both the pressure sensing module and the ultrasonic probe are connected to the second kettle cover through holes; both the first kettle cover through holes and the second kettle cover through holes are threaded holes; by rotating the ultrasonic probe to adjust the position of the end face of the ultrasonic probe located in the sample cavity, and by rotating the pressure sensing module to adjust the position of the end face of the pressure sensing module located in the sample cavity.

6. The method for testing the ultrasonic response of a natural gas hydrate formation according to claim 2, characterized in that, at least one of the first kettle cover and the second kettle cover is detachably installed on the platform.

7. The ultrasonic response test method for natural gas hydrate formation according to claim 6, characterized in that, the first kettle cover is detachably installed on the platform; and, the platform is provided with an installation groove; the bottom of the first kettle cover is provided with a vertical protrusion and a horizontal protrusion, the vertical protrusion can extend into the installation groove, and the horizontal protrusion is arranged on the inner wall of the first kettle cover and can abut against the top surface of the platform.

8. The ultrasonic response test method for natural gas hydrate formation according to claim 2, characterized in that, the step S30 includes: collecting the ultrasonic waveform of the natural gas hydrate sample through an ultrasonic probe; establishing the correlation relationship between the formation characteristic parameters, ultrasonic frequency and ultrasonic wave velocity; calculating the unknown physical property parameters of the natural gas hydrate sample according to the correlation relationship and the known actual formation physical property parameters.

9. The ultrasonic response test method for natural gas hydrate formation according to claim 1, characterized in that, the gas injection device injects inert gas into the kettle body for pressure increase and pressure maintenance.

10. An ultrasonic response clamping device, characterized in that, for the ultrasonic response test method for natural gas hydrate formation according to any one of claims 1-9, the ultrasonic response clamping device includes: a kettle body, an ultrasonic probe, a pressure sensing module, a pressure tester and a gas injection device, the kettle body includes a platform, a first kettle cover and a second kettle cover arranged oppositely, the first kettle cover and the second kettle cover are both installed on the platform, and a sample cavity is arranged between the first kettle cover and the second kettle cover; the second kettle cover is provided with a plurality of second kettle cover through holes, at least one of the second kettle cover through holes is connected with the pressure sensing module, and at least one of the second kettle cover through holes is connected with the ultrasonic probe; the first kettle cover is provided with a support structure; the gas injection device is connected to the kettle body to inject gas into the kettle body, and the pressure tester is installed on the kettle body to detect the air pressure in the kettle body.

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