An in-situ measurement device for rock elastic wave velocity under ultra-deep temperature and pressure and a method for using the same

Abstract

The invention discloses an in-situ measurement device for rock elastic wave velocity under ultra-deep temperature and pressure and a method for using the device, comprising an ultrasonic transducer, an ultrasonic buffer rod, a sample chamber and a high-pressure container; the ultrasonic transducer is connected to the tail of the ultrasonic buffer rod, the head of the ultrasonic buffer rod seals the sample chamber, the head of the ultrasonic buffer rod and the sample chamber are placed inside the high-pressure container, and the tail of the ultrasonic buffer rod passes through the high-pressure container and is placed outside the high-pressure container; the invention successfully realizes an experiment of simulating in-situ detection of rock elastic wave velocity under ultra-deep temperature and pressure of shallower than 12 kilometers by sealing the rock sample to be tested, solves the problem that the rock sample to be tested cannot be sealed when using gas as the pressure transmission medium, thereby causing the rock ultrasonic signal to be weak, and the method is simple and easy to implement, and has broad prospects for technical promotion.

Description

Technical Field

[0001] The invention relates to an in-situ measurement device for rock elastic wave velocity under ultra-deep temperature and pressure and a use method, belonging to the technical field of high-temperature and high-pressure in-situ measurement. Background Art

[0002] The propagation velocity of seismic waves in ultra-deep rocks inside the Earth is a geophysical parameter that must be known when people use geophysical methods such as earthquakes to detect geological conditions such as ultra-deep material composition and structural structure, temperature distribution, and fine structure of structural interfaces. Despite the dispersion phenomenon, the elastic wave velocity of rocks measured by ultrasound can be extrapolated to geophysical exploration applications such as earthquakes.

[0003] Looking at the current development status of laboratory measurement technology for rock physical parameters at home and abroad, in recent years, in ultra-deep seismic exploration geophysics practice, such as ultra-deep seismic exploration geophysics practice at a depth of more than 6000-7000 meters, there is basically no substantial breakthrough in the laboratory in-situ measurement technology of ultra-deep rock elastic wave velocity, which is increasingly urgently needed. For example, the advanced MTS rock physical parameter testing system in the United States uses silicone oil or mineral oil as the pressure transmission medium, so that the maximum simulated temperature cannot exceed 250°C when the maximum simulated static rock pressure is reached, which is only equivalent to the temperature corresponding to a depth of about 6000-7000 meters in the earth. At present, the main reasons why domestic and foreign laboratories, related geophysical instruments and analysis and testing companies have failed to make substantial breakthroughs can be summarized as follows: 1. There is no high-temperature and high-pressure experimental platform or elastic wave measurement technology that can simulate ultra-deep temperature and pressure conditions; 2. Elastic wave measurement technology is incompatible with high-temperature and high-pressure experimental platforms.

[0004] At present, with the massive exploitation and consumption of shallow energy and mineral resources around the world, the exploration strategies of natural energy and resources in various countries have begun to shift from the shallow part of the earth to deeper. For example, the average depth of the reservoir of China's Shunbei oil and gas field, which is being exploited, reaches 7,300 meters. According to the idea of ​​"exploration first, then exploitation", this requires exploration to precede exploitation, which urgently requires the ability to conduct ultra-deep geophysical exploration at a depth of more than 6,000-7,000 meters. At the same time, this also urgently requires rock physical parameters under ultra-deep temperature and pressure at a depth of more than 6,000-7,000 meters, or in other words, it urgently requires rock elastic wave velocity at a depth of less than 12 kilometers, corresponding to the highest temperature and pressure of about 350℃ and 350MPa.

[0005] Generally, when measuring the elastic wave velocity of rocks under simulated ultra-deep temperature and pressure, the pressure transmission medium that provides the confining pressure is a fluid, and the temperature must be raised while the pressure is applied, which makes it extremely difficult to seal the rock samples. If the rock samples cannot be strictly sealed, the signal propagation of the rock ultrasonic wave will be affected. This is also the reason why high temperature and high pressure experimental conditions are rarely present at the same time when conducting similar elastic wave velocity measurement experiments under ultra-deep temperature and pressure. For example, when such experiments were conducted internationally before, the highest temperature and pressure that could be reached simultaneously was only 200°C and 100MPa. Therefore, solving the problem of rock sealing under simulated ultra-deep temperature and pressure and the problem of weak rock ultrasonic signals is the key to increasing the maximum temperature and pressure of such experiments. At present, there is a high temperature and high pressure experimental platform composed of high temperature equipment and high pressure equipment. This platform has the ability to simulate temperatures and pressures exceeding 350°C and 350MPa. There is already a high-pressure container that can be connected to a high-temperature and high-pressure experimental platform through a container interface to introduce high-pressure gas, forming a high-temperature and high-hydrostatic pressure environment inside the high-pressure container. Therefore, high-temperature and high-pressure equipment and high-pressure containers can be used in combination to form a stable high-temperature and high-pressure experimental environment. However, the problem of poor sealing of rock samples, which leads to weak rock ultrasonic signals or even no rock ultrasonic signals being detected, has not yet been solved. Summary of the invention

[0006] The technical problem to be solved by the present invention is: to provide an in-situ measurement device for rock elastic wave velocity under ultra-deep temperature and pressure and a method for using the device, which can seal the rock sample and make the rock sample fit closely with an ultrasonic buffer rod that transmits ultrasonic waves, so as to solve the problem of poor sealing of rock samples in in-situ measurement of rock elastic wave velocity under high temperature and high pressure, resulting in weak rock ultrasonic signals or even no rock ultrasonic signals being detected during the experiment.

[0007] The technical solution of the present invention is: an in-situ measurement device for rock elastic wave velocity under ultra-deep temperature and pressure, which includes an ultrasonic transducer, an ultrasonic buffer rod, a sample chamber and a high-pressure container; the ultrasonic transducer is connected to the tail of the ultrasonic buffer rod, the head of the ultrasonic buffer rod is connected to the sample chamber, the head of the ultrasonic buffer rod and the sample chamber are placed inside the high-pressure container, and the tail of the ultrasonic buffer rod passes through the high-pressure container and is placed outside the high-pressure container.

[0008] Preferably, the ultrasonic buffer rod is made of steel material and is a rod-shaped object with smooth end surfaces and smooth side surfaces.

[0009] Preferably, the sample chamber is composed of a tungsten carbide block and a metal sealing cap, and the tungsten carbide block is arranged at the bottom of the metal sealing cap and forms a tight fit with the metal sealing cap.

[0010] Preferably, the tungsten carbide block has a thickness greater than 3 mm, and both end surfaces and side surfaces of the tungsten carbide block are smooth.

[0011] Preferably, the metal sealing cap comprises a cap body and an outer wall step at the top of the cap body; the step is coaxially formed on the top of the cap body and protrudes from the cap body, and the cap body wall thickness is 0.01-0.5 mm; the inner circumference of the inner circumference of the metal sealing cap is smooth, and the inner end bottom surface is smooth.

[0012] Preferably, the ultrasonic transducer and the ultrasonic buffer rod are connected by gluing with high temperature resistant glue.

[0013] Preferably, the connection between the ultrasonic buffer rod and the sample chamber includes extending the head of the ultrasonic buffer rod into the sample chamber, and performing welding sealing at the connection between the ultrasonic buffer rod and the outer surface of the sample chamber.

[0014] Preferably, the operating temperature range of the in-situ measurement device for rock elastic wave velocity under ultra-deep temperature and pressure is from room temperature to 350°C, and the operating pressure range is from normal pressure to 350MPa.

[0015] Preferably, a method for using an in-situ measurement device for rock elastic wave velocity under ultra-deep temperature and pressure comprises:

[0016] S1. When using the in-situ measurement device for rock elastic wave velocity under ultra-deep temperature and pressure, the assembly and sealing process of the rock sample to be measured includes: firstly placing the rock sample to be measured in the sample chamber, then pasting the ultrasonic transducer at the tail end of the ultrasonic buffer rod, and placing the ultrasonic buffer rod in the sample chamber, so that the ultrasonic buffer rod, the rock sample to be measured and the sample chamber are tightly fitted, and then welding and sealing are performed at the connection between the ultrasonic buffer rod and the outer surface of the sample chamber, and finally placing the welded and sealed sample chamber into a high-pressure container, and the tail of the ultrasonic buffer rod extends out of the high-pressure container, so as to form an in-situ measurement device for rock elastic wave velocity under ultra-deep temperature and pressure that seals the rock sample to be measured;

[0017] S2. When using the in-situ measurement device for rock elastic wave velocity under ultra-deep temperature and pressure to conduct an in-situ measurement experiment of rock elastic wave velocity under ultra-deep temperature and pressure, firstly put the high-pressure container with the sample chamber into the high-temperature device, extend the tail of the ultrasonic buffer rod out of the high-temperature device, then set a cooling circulating fluid at the tail of the ultrasonic buffer rod, connect the gas interface of the high-pressure container to the high-pressure device, and finally connect the ultrasonic device at the ultrasonic transducer to conduct in-situ measurement of rock elastic wave velocity under ultra-deep temperature and pressure;

[0018] S3. After the in-situ measurement experiment of rock elastic wave velocity under ultra-deep temperature and pressure is completed, the process of disassembling the in-situ measurement device of rock elastic wave velocity under ultra-deep temperature and pressure includes: first disconnecting the connection between the ultrasonic transducer and the ultrasonic equipment, removing the cooling circulating fluid when the high-pressure container is cooled to room temperature, disconnecting the connection between the gas interface of the high-pressure container and the high-pressure equipment, and then taking the high-pressure container out of the high-temperature equipment, taking the sample chamber and the ultrasonic buffer rod out of the high-pressure container, and finally clamping the tail of the ultrasonic buffer rod on a lathe, using a turning tool to turn off the welding point, separating the ultrasonic buffer rod and the sample chamber, and then taking out the rock sample to be tested, thereby completing the disassembly of the in-situ measurement device of rock elastic wave velocity under ultra-deep temperature and pressure.

[0019] The beneficial effects of the invention are as follows: the invention provides an in-situ measurement device for rock elastic wave velocity under ultra-deep temperature and pressure and a method for using the device, which can measure rock ultrasonic signals under ultra-deep temperature and pressure conditions while sealing rock samples, thereby solving the problem of weak rock ultrasonic signals caused by poor sealing of rock samples during in-situ measurement of rock elastic wave velocity under simulated high temperature and high pressure environments. Compared with the prior art, the invention improves the temperature and pressure of the experiment, realizes the measurement of rock elastic wave velocity under ultra-deep temperature and pressure of less than 12 kilometers, and the operation method is simple and easy, with potential technology promotion value. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the longitudinal section structure of the present invention;

[0021] Figure 2 A graph showing the relationship between the longitudinal wave waveform and the temperature of sandstone measured by the present invention;

[0022] Description of reference numerals:

[0023] 1. Ultrasonic transducer, 2. Ultrasonic buffer rod, 3. Rock sample to be tested, 4. Tungsten carbide block, 5. Metal sealing cap, 6. High-pressure container, 7. Welding point, 8. Gas interface of high-pressure container. DETAILED DESCRIPTION

[0024] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0025] Implementation Example 1: Reference Figure 1 to Figure 2An in-situ measurement device for rock elastic wave velocity under ultra-deep temperature and pressure comprises an ultrasonic transducer 1, an ultrasonic buffer rod 2, a sample chamber and a high-pressure container 6; the ultrasonic transducer 1 is connected to the tail of the ultrasonic buffer rod 2, the head of the ultrasonic buffer rod 2 is connected to the sample chamber, the head of the ultrasonic buffer rod 2 and the sample chamber are placed inside the high-pressure container 6, and the tail of the ultrasonic buffer rod 2 passes through the high-pressure container 6 and is placed outside the high-pressure container 6.

[0026] Preferably, the ultrasonic buffer rod 2 is made of steel material and is a rod-shaped object with smooth end faces and smooth side faces. It is used for propagation of rock ultrasonic waves and is combined with the sample chamber to seal the rock sample 3 to be tested.

[0027] Preferably, the sample chamber is composed of a tungsten carbide block 4 and a metal sealing cap 5. The tungsten carbide block 4 is arranged at the bottom of the metal sealing cap 5 and forms a tight fit with the metal sealing cap 5. The sample chamber is used to seal the rock sample 3 to be tested and reflect the rock ultrasonic signal.

[0028] Preferably, the tungsten carbide block 4 has a thickness greater than 3 mm, and both end faces and side faces of the tungsten carbide block 4 are smooth. When the thickness of the tungsten carbide block 4 is greater than 3 mm, signal overlap between the interface between the rock sample 3 to be tested and the bottom end of the metal sealing cap 5 can be avoided, which affects the rock ultrasonic travel time reading. Moreover, because the acoustic impedance of the tungsten carbide 4 is greatly different from that of the rock, the tungsten carbide 4 also increases the reflected rock ultrasonic signal of the interface. The tungsten carbide 4 can be replaced by other hard materials with a large difference in acoustic impedance from the rock.

[0029] Preferably, the metal sealing cap 5 comprises a cap body and an outer wall step at the top of the cap body; the step is coaxially formed on the top of the cap body and protrudes from the cap body, and the wall thickness of the cap body is 0.01-0.5 mm; the inner circumferential surface of the inner circumferential surface of the metal sealing cap 5 is smooth, and the inner end bottom surface is smooth; the metal sealing cap 5 is made of a metal material that can be welded to the ultrasonic buffer rod 2, and the metal material increases the upper limit of the experimental temperature and the experimental pressure to a certain extent; the purpose of setting the wall thickness of the cap body to 0.01-0.5 mm is to transfer the external pressure to the rock sample 3 to be tested, so that the experiment can better simulate the actual pressure; the smooth circumferential surface can make the metal sealing cap 5 fit closely with the ultrasonic buffer rod 2 and the tungsten carbide block 4, and the smooth inner end bottom surface can make the metal sealing cap 5 fit closely with the tungsten carbide block 4 and form a tight fit, ultimately achieving the purpose of sealing the rock sample 3 to be tested.

[0030] Preferably, the ultrasonic transducer 1 and the ultrasonic buffer rod 2 are connected by gluing with high temperature resistant glue, so that the ultrasonic transducer 1 is connected to the ultrasonic buffer rod 2 .

[0031] Preferably, the connection between the ultrasonic buffer rod 2 and the sample chamber includes extending the head of the ultrasonic buffer rod 2 into the sample chamber, and performing welding sealing at the connection between the ultrasonic buffer rod 2 and the outer surface of the sample chamber; the welding seal makes the connection strength between the ultrasonic buffer rod 2 and the sample chamber high and the sealing good, and the welding sealing method allows the ultrasonic buffer rod 2 and the sample chamber to be used repeatedly, thereby reducing the use cost of the device.

[0032] Preferably, the operating temperature range of the in-situ measurement device of rock elastic wave velocity under ultra-deep temperature and pressure is from room temperature to 350°C, and the operating pressure range is from room pressure to 350MPa; this operating temperature and pressure range has reached the temperature and pressure for simulating the measurement of rock elastic wave velocity under ultra-deep temperature and pressure inside the earth, and improves the upper limit of temperature and pressure for in-situ measurement of rock elastic wave velocity in the laboratory.

[0033] Preferably, a method for using an in-situ measurement device for rock elastic wave velocity under ultra-deep temperature and pressure comprises:

[0034] S1. When using the in-situ measurement device for rock elastic wave velocity under ultra-deep temperature and pressure, the assembly and sealing process of the rock sample 3 to be measured includes: firstly placing the rock sample 3 to be measured in the sample chamber, then pasting the ultrasonic transducer 1 on the tail end of the ultrasonic buffer rod 2, and placing the ultrasonic buffer rod 2 in the sample chamber so that the ultrasonic buffer rod 2, the rock sample 3 to be measured and the sample chamber are closely fitted, and then welding and sealing are performed at the connection between the ultrasonic buffer rod 2 and the outer surface of the sample chamber, and finally the welded and sealed sample chamber is placed in a high-pressure container, and the tail of the ultrasonic buffer rod 2 extends out of the high-pressure container 6 to form an in-situ measurement device for rock elastic wave velocity under ultra-deep temperature and pressure that seals the rock sample to be measured; the ultrasonic buffer rod 2 is connected to the ultrasonic transducer 1 for transmitting and receiving rock ultrasonic signals, and the function of the high-pressure container 6 is to form a closed high-temperature and high-hydrostatic pressure experimental environment; this device can seal the rock sample 3 to be measured, and by making the rock sample 3 to be measured and the ultrasonic buffer rod 2 closely fit, it is ensured that the rock ultrasonic signal can be well transmitted.

[0035] S2. When using the in-situ measurement device for rock elastic wave velocity under ultra-deep temperature and pressure to conduct an in-situ measurement experiment of rock elastic wave velocity under ultra-deep temperature and pressure, firstly put the high-pressure container 6 equipped with the sample chamber into the high-temperature equipment, the high-temperature equipment provides the specified temperature for the experiment, extend the tail of the ultrasonic buffer rod 2 out of the high-temperature equipment for connecting the ultrasonic equipment, and then set a cooling circulating fluid at the tail of the ultrasonic buffer rod 2 to keep the tail at room temperature, so as to protect the ultrasonic transducer 1 from being damaged by high temperature, and connect the high-pressure container gas interface 8 to the high-pressure equipment, the high-pressure equipment is used to provide high-pressure gas to the high-pressure container 6, and form a high-temperature and high-hydrostatic pressure environment in the high-pressure container, and finally connect the ultrasonic equipment at the ultrasonic transducer 1 to conduct in-situ measurement of rock elastic wave velocity under ultra-deep temperature and pressure, which solves the problem of incompatibility between the ultrasonic equipment and the high-temperature and high-pressure experimental environment, and realizes the in-situ measurement experiment of rock elastic wave velocity under simulated high-temperature and high-pressure conditions.

[0036] S3. After the in-situ measurement experiment of rock elastic wave velocity under ultra-deep temperature and pressure is completed, the process of disassembling the in-situ measurement device of rock elastic wave velocity under ultra-deep temperature and pressure includes: first disconnecting the connection between the ultrasonic transducer 1 and the ultrasonic equipment, removing the cooling circulating fluid when the high-pressure container 6 is cooled to room temperature, disconnecting the connection between the high-pressure container gas interface 8 and the high-pressure equipment, and then taking the high-pressure container 6 out of the high-temperature equipment, taking the sample chamber and the ultrasonic buffer rod 2 out of the high-pressure container 6, and finally clamping the tail of the ultrasonic buffer rod 2 on a lathe, using a turning tool to turn off the welding point 7, separating the ultrasonic buffer rod 2 and the sample chamber and taking out the rock sample 3 to be tested, thereby completing the disassembly of the in-situ measurement device of rock elastic wave velocity under ultra-deep temperature and pressure; this device can be reused many times, has low economic cost, good practicality, and has potential technology promotion value.

[0037] Actual testing was carried out on the rock sample 3 to be tested. The results showed that this in-situ measurement device for rock elastic wave velocity under ultra-deep temperature and pressure has good sealing ability for the rock sample 3 to be tested under the experimental conditions of the highest temperature and pressure of 350℃ and 350MPa, and clean and clear rock ultrasonic signals can be measured under ultra-deep temperature and pressure.

[0038] The above contents are further detailed descriptions of the present invention in combination with specific preferred embodiments, and it cannot be determined that the specific implementation of the present invention is limited to these descriptions. For ordinary technicians in the technical field to which the present invention belongs, several simple deductions or substitutions can be made without departing from the concept of the present invention, which should be regarded as falling within the scope of protection of the present invention.

Claims

1. An in-situ measurement device for rock elastic wave velocity under ultra-deep temperature and pressure, comprising an ultrasonic transducer (1), an ultrasonic buffer rod (2), a sample chamber and a high-pressure container (6), characterized in that: The ultrasonic transducer (1) is connected to the tail of the ultrasonic buffer rod (2), the head of the ultrasonic buffer rod (2) is connected to the sample chamber, the head of the ultrasonic buffer rod (2) and the sample chamber are placed inside the high-pressure container (6), and the tail of the ultrasonic buffer rod (2) passes through the high-pressure container (6) and is placed outside the high-pressure container (6); the sample chamber is composed of a tungsten carbide block (4) and a metal sealing cap (5), the tungsten carbide block (4) is arranged at the bottom of the metal sealing cap (5) and forms a tight fit with the metal sealing cap (5); the metal sealing cap (5) comprises a cap body and an outer wall step at the top of the cap body; the step is coaxially formed at the top of the cap body and protrudes from the cap body, and the cap body wall thickness is 0.01-0.5 mm; the inner circumferential surface of the metal sealing cap (5) is smooth, and the inner end bottom surface is smooth.

2. The in-situ measurement device for rock elastic wave velocity under ultra-deep temperature and pressure according to claim 1, characterized in that: The ultrasonic buffer rod (2) is made of steel material and is a rod-shaped object with smooth end surfaces and smooth side surfaces.

3. The in-situ measurement device for rock elastic wave velocity under ultra-deep temperature and pressure according to claim 1, characterized in that: The tungsten carbide block (4) has a thickness greater than 3 mm, and both end surfaces of the tungsten carbide block (4) are smooth and the side surfaces are smooth.

4. The in-situ measurement device for rock elastic wave velocity under ultra-deep temperature and pressure according to claim 1, characterized in that: The ultrasonic transducer (1) and the ultrasonic buffer rod (2) are connected by gluing using high temperature resistant glue.

5. The in-situ measurement device for rock elastic wave velocity under ultra-deep temperature and pressure according to claim 1, characterized in that: The connection between the ultrasonic buffer rod (2) and the sample chamber comprises the head of the ultrasonic buffer rod (2) extending into the sample chamber, and welding and sealing at the connection between the ultrasonic buffer rod (2) and the outer surface of the sample chamber.

6. The in-situ measurement device for rock elastic wave velocity under ultra-deep temperature and pressure according to claim 1, characterized in that: The operating temperature range of the in-situ measurement device for rock elastic wave velocity under ultra-deep temperature and pressure is from room temperature to 350°C, and the operating pressure range is from normal pressure to 350MPa.

7. The method for using the in-situ measurement device for rock elastic wave velocity under ultra-deep temperature and pressure according to claim 1, comprising: S1. When using the in-situ measurement device for rock elastic wave velocity under ultra-deep temperature and pressure, the assembly and sealing process of the rock sample (3) to be measured includes: firstly placing the rock sample (3) to be measured in the sample chamber, then pasting the ultrasonic transducer (1) on the tail end of the ultrasonic buffer rod (2), and placing the ultrasonic buffer rod (2) in the sample chamber so that the ultrasonic buffer rod (2), the rock sample (3) to be measured and the sample chamber are tightly fitted, and then welding and sealing are performed at the connection between the ultrasonic buffer rod (2) and the outer surface of the sample chamber, and finally placing the welded and sealed sample chamber into a high-pressure container, and the tail end of the ultrasonic buffer rod (2) extends out of the high-pressure container (6), so as to form an in-situ measurement device for rock elastic wave velocity under ultra-deep temperature and pressure that seals the rock sample to be measured; S2. When using the in-situ measurement device for rock elastic wave velocity under ultra-deep temperature and pressure to conduct an in-situ measurement experiment for rock elastic wave velocity under ultra-deep temperature and pressure, firstly, a high-pressure container (6) containing a sample chamber is placed in a high-temperature device, and the tail of the ultrasonic buffer rod (2) is extended out of the high-temperature device. Then, a cooling circulating fluid is provided at the tail of the ultrasonic buffer rod (2), and the gas interface (8) of the high-pressure container is connected to the high-pressure device. Finally, the ultrasonic device is connected at the ultrasonic transducer (1) to conduct in-situ measurement of rock elastic wave velocity under ultra-deep temperature and pressure. S3. After the in-situ measurement experiment of rock elastic wave velocity under ultra-deep temperature and pressure is completed, the process of disassembling the in-situ measurement device of rock elastic wave velocity under ultra-deep temperature and pressure includes: first disconnecting the connection between the ultrasonic transducer (1) and the ultrasonic equipment, removing the cooling circulating fluid when the high-pressure container (6) is cooled to room temperature, disconnecting the connection between the high-pressure container gas interface (8) and the high-pressure equipment, then taking the high-pressure container (6) out of the high-temperature equipment, taking the sample chamber and the ultrasonic buffer rod (2) out of the high-pressure container (6), finally clamping the tail of the ultrasonic buffer rod (2) on a lathe, using a lathe tool to turn off the welding point (7), separating the ultrasonic buffer rod (2) and the sample chamber, and taking out the rock sample (3) to complete the disassembly of the in-situ measurement device of rock elastic wave velocity under ultra-deep temperature and pressure.

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