An in-situ sampling experimental device for seabed

Abstract

The present application relates to the technical field of seabed sampling equipment, and discloses a seabed in-situ sampling experiment device, which comprises an experiment main body, a hydraulic system, a hydraulic oil cylinder and a control system, a sample cavity and a confining pressure cavity are formed in the inside of the experiment main body, a pressurizing oil cylinder is arranged at the top of the experiment main body, and the hydraulic oil cylinder is communicated with the confining pressure cavity; a hollow drill rod and a drilling device are movably assembled at the bottom of the experiment main body, the top end of the drill rod is communicated with the sample cavity, and a control switch for opening or closing the sample cavity is arranged at the bottom end of the sample cavity. When the seabed in-situ sampling experiment is carried out, the collected rock sample is transported into the sample cavity through the hollow drill rod, the control switch is used for water conservation, gas conservation and pressure conservation of the rock sample, and the fidelity sampling is ensured, after the sampling is completed, the hydraulic system controls the pressurizing oil cylinder and the hydraulic oil cylinder to apply pressure to the sample cavity and the confining pressure cavity respectively, and the control system can record the mechanical parameters in real time, so that the effect of in-situ sampling for mechanical property experiment is realized.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of seabed sampling equipment, in particular to a seabed in-situ sampling experiment device. BACKGROUND

[0002] Seabed sediment mechanical property in-situ testing and sample acquisition are indispensable links for seabed oil and gas resource exploration, marine environment monitoring and marine engineering construction. With the promotion of the strategy of building a strong marine country, the number of projects such as China's marine oil and gas resource development and marine engineering construction increases, and the difficulty of survey and construction increases, and the demand for detailed physical and mechanical parameters of seabed sediments increases in accuracy.

[0003] The conventional method for obtaining seabed sediment physical and mechanical parameters is to sample first and then test in the laboratory. Due to the characteristics of seabed sediments such as high water content, high sensitivity, high pressure and easy disturbance, the mechanical parameters of the sediments obtained by conventional sampling and laboratory test do not have in-situ information, and the engineering application value is greatly reduced. The conventional in-situ detection method of seabed sediment is mainly large-scale static sounding test, which has high test cost, slow test speed and large disturbance to the surface sediment, greatly reducing the efficiency of sediment physical and mechanical parameter test, and cannot meet the increasing demand for sediment physical and mechanical parameters.

[0004] Application publication No. CN102182414A discloses a deep-sea sediment core pressure maintaining device matched with a seabed drilling machine, which comprises an upper sealing cover, a metal hollow drill rod, a sampling pipe and a lower sealing cover. The metal hollow drill rod is provided with the sampling pipe, and the metal hollow drill rod is connected with the upper sealing cover and the lower sealing cover through fine thread. The upper sealing cover and the lower sealing cover respectively comprise an inflation valve, a top cover, a pressure shell, an inflatable air cushion and an O-ring. The pressure shell is provided with the top cover and the inflatable air cushion, and the O-ring is arranged between the pressure shell and the top cover and the inflatable air cushion. The top cover is provided with the inflation valve.

[0005] The deep-sea sediment core pressure maintaining device can maintain the in-situ pressure during the process of extracting seabed sediments from the seabed to the sea surface by being used in combination with the seabed drilling machine. However, it can only be applied to the existing sampling and laboratory test, and is used to ensure the integrity of the sample as much as possible during the process of transferring the sample from sampling to the laboratory, and cannot be applied to in-situ sampling experiment, and cannot be used for in-situ test of mechanical properties during sampling. SUMMARY

[0006] The purpose of the present application is to provide a seabed in-situ sampling experiment device to solve the problem that the in-situ test of mechanical properties during sampling cannot be performed in the prior art.

[0007] In order to achieve the above object, the present application provides a seabed in-situ sampling experiment device, comprising an experiment main body, a hydraulic system, a hydraulic cylinder and a control system, the experiment main body comprises a shell, the inside of the shell is sequentially formed with a sample cavity for accommodating a sample and a confining pressure cavity for applying confining pressure to the sample cavity from inside to outside, the top of the experiment main body is provided with a pressurizing cylinder for applying axial hydraulic pressure to the sample in the sample cavity, the hydraulic cylinder is communicated with the confining pressure cavity to apply hydraulic pressure to the confining pressure cavity, the hydraulic cylinder and the pressurizing cylinder are electrically connected with the hydraulic system, and the hydraulic system is electrically connected with the control system.

[0008] The bottom of the experiment main body is also movably provided with a hollow drill rod and a drilling device in transmission connection with the drill rod, the drilling device is used for driving the drill rod to axially extend or retract to drill a sample, the top end of the drill rod is communicated with the sample cavity, the bottom end of the sample cavity is provided with a control switch used for opening or closing the sample cavity, and the control switch and the drilling device are electrically connected with the control system.

[0009] Preferably, the drilling device comprises a rotor motor and a rotating sleeve in transmission connection with the rotor motor through a gear assembly, the drill rod is threadedly assembled in the rotating sleeve, the top end of the rotating sleeve is communicated with the sample cavity, and the control switch is arranged between the rotating sleeve and the sample cavity.

[0010] Preferably, the bottom of the experiment main body is provided with a sleeve extending to the outside, the drilling device and the drill rod are arranged in the sleeve, a resistance sensor is arranged on the outer wall of the part of the sleeve located outside the experiment main body, the resistance sensor is used for detecting resistance in the drilling process, and the resistance sensor is electrically connected with the control system.

[0011] Preferably, a temperature sensor and a pore water pressure sensor are also arranged on the outer wall of the part of the sleeve located outside the experiment main body, the temperature sensor and the pore water pressure sensor are electrically connected with the control system, the temperature sensor is used for detecting seabed temperature, and the pore water pressure sensor is used for detecting pore water pressure of seabed rock.

[0012] Preferably, a constant temperature cavity is also formed in the inside of the shell, the constant temperature cavity is located outside the confining pressure cavity, and the seabed in-situ sampling experiment device further comprises a constant temperature device communicated with the constant temperature cavity, and the constant temperature device is used for conveying constant temperature medium into the constant temperature cavity.

[0013] Preferably, the constant temperature device comprises a heating pipe used for heating constant temperature medium and a pressure cylinder used for driving constant temperature medium to flow, and the heating pipe and the pressure cylinder are electrically connected with the control system.

[0014] Preferably, a pressure gauge and a flow meter are further included, and the pressure gauge and the flow meter are arranged on the pipeline between the thermostat device and the thermostat cavity and on the pipeline between the hydraulic oil cylinder and the confining pressure cavity.

[0015] Preferably, the upper portion of the experimental main body is further provided with a counterweight device for keeping the experimental main body balanced during sampling.

[0016] Preferably, a positioning device is further included, and the positioning device is arranged on the top of the experimental main body.

[0017] Preferably, a cooling device is further included for cooling the hydraulic oil, and the cooling device is electrically connected with the control system.

[0018] Compared with the prior art, the experimental main body of the seabed in-situ sampling experimental device is provided with a sample cavity and a confining pressure cavity in the shell, and a drill rod and a drilling device are arranged at the bottom of the experimental main body. When the seabed in-situ sampling experiment is performed, the operator controls the drilling device to work through the control system, drives the drill rod to extend axially and collect seabed rock samples, and the collected rock samples are transported into the sample cavity through the hollow drill rod. The sample cavity and the drill rod are isolated by using the control switch, so that the rock samples are kept water, gas and pressure, and the fidelity sampling is ensured. After the sampling is completed, the control system can automatically control the hydraulic system, the hydraulic system controls the pressurizing oil cylinder and the hydraulic oil cylinder to apply pressure to the sample cavity and the confining pressure cavity respectively, the underwater triaxial compression experiment can be performed, the control system can record the mechanical parameters in real time, and the effect of in-situ sampling for mechanical property experiment is realized. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 is a structural schematic view of the seabed in-situ sampling experimental device of the present application;

[0020] Figure 2 is Figure 1 a structural schematic view of the thermostat device of the seabed in-situ sampling experimental device.

[0021] In the figure, 1 is a drill rod, 2 is a drilling device, 3 is a resistance sensor, 4 is a temperature sensor, 5 is a rotating sleeve, 6 is a control switch, 7 is a thermostat cavity, 8 is a confining pressure cavity, 9 is a thermostat device, 10 is a pressure gauge, 11 is a flow meter, 12 is a positioning device, 13 is a cooling device, 14 is a control system, 15 is a hydraulic system, 16 is a pore water pressure sensor, 17 is a hydraulic oil cylinder, 18 is a counterweight device, 19 is a pressurizing oil cylinder, 20 is a sleeve, 21 is a sample cavity, 22 is a gear assembly, 23 is a rotor motor, 24 is a pressure cylinder, and 25 is a heating pipe. DETAILED DESCRIPTION

[0022] The specific embodiments of the present application are described in further detail below in conjunction with the accompanying drawings and examples. The following examples are used to illustrate the present application but are not intended to limit the scope of the present application.

[0023] A preferred embodiment of the seabed in-situ sampling experimental device of the present application is shown in Figure 1 and Figure 2 The seabed in-situ sampling experimental device includes an experimental body, a hydraulic system 15, a hydraulic cylinder 17, and a control system 14. The experimental body is used to collect seabed rock samples and conduct underwater triaxial compression experiments. The hydraulic system 15 is used to control the oil pressure of the hydraulic cylinder 17. The control system 14 is used to control the hydraulic system 15. In this embodiment, the control system 14 is a computer host inside the ship body. The computer host is responsible for writing commands, conversion, and converting electrical signals into mechanical signals to control the hydraulic system 15.

[0024] The experimental body includes an outer shell, which is a cylindrical structure. Inside the outer shell, a sample cavity 21 and a confining pressure cavity 8 are sequentially formed from inside to outside. The sample cavity 21 is used to accommodate the collected samples to be tested. The confining pressure cavity 8 can be filled with seawater or hydraulic oil to apply confining pressure to the sample cavity 21, simulating the pressure environment of the sample on the seabed. The overall structure of the sample cavity 21 and the confining pressure cavity 8 is the same as that of the existing triaxial instrument, which is not described in detail here.

[0025] The experimental body also has a pressurizing cylinder 19 arranged at the top. The pressure head of the pressurizing cylinder 19 is arranged towards the sample cavity 21. The pressurizing cylinder 19 is used to apply axial hydraulic pressure to the sample in the sample cavity 21 to conduct compression experiments on the sample. The hydraulic cylinder 17 is in communication with the confining pressure cavity 8. The hydraulic cylinder 17 is used to deliver hydraulic oil of a certain pressure to the confining pressure cavity 8 to provide a certain confining pressure to the sample. The pressurizing cylinder 19, the hydraulic cylinder 17, the sample cavity 21, and the confining pressure cavity 8 cooperate to form a triaxial instrument, which can conduct triaxial compression tests on the collected rock samples.

[0026] The hydraulic cylinder 17 and the pressurizing cylinder 19 are electrically connected to the hydraulic system 15. The hydraulic system 15 is electrically connected to the control system 14. The control system 14 converts the electrical signals of the computer host into mechanical signals and then transmits the mechanical signals to the hydraulic system 15. The hydraulic system 15 controls the oil pressure of the hydraulic cylinder 17 and the pressurizing cylinder 19 according to the mechanical signals, thereby controlling the pressure on the sample during the triaxial compression experiment.

[0027] The bottom of the experimental main body is also provided with a drill rod 1 and a drilling device 2, the drill rod 1 is hollow and movably arranged at the bottom of the experimental main body in the axial direction, and the top end of the drill rod 1 is communicated with the sample cavity 21. The drilling device 2 is electrically connected with the control system 14, the control system 14 is used for transmitting an action command to the drilling device 2, the drilling device 2 is drivingly connected with the drill rod 1, and the drilling device 2 is used for driving the drill rod 1 to axially extend and retract. When the drilling device 2 drives the drill rod 1 to extend downward, the drill rod 1 can drill and cut the rock of the seabed, and the deep-sea rock sample can be taken through the hollow inner cavity; after the seabed rock sample or the mud sample enters the sample cavity 21 through the drill rod 1, the drilling device 2 drives the drill rod 1 to retract upward.

[0028] The bottom end of the sample cavity 21 is provided with a control switch 6, which is used for opening or closing the sample cavity 21, and the control switch 6 is electrically connected with the control system 14. After the drill rod 1 drills and cuts the rock of the seabed or the mud sample, the control system 14 transmits an opening signal to the control switch 6, the control switch 6 is automatically opened, the drill rod 1 sends the sample into the sample cavity 21, then the control switch 6 is automatically closed, so that the sample in the sample cavity 21 is prevented from flowing out to the drill rod 1, and then the drilling device 2 can drive the drill rod 1 to retract.

[0029] In the embodiment, all the cavities are made of sealed high-strength alloy materials which are not easy to corrode, and the connecting parts are sealed by sealing rings (all the connecting parts are seamlessly welded and sealed), so that the seawater cannot enter the inside of the device in the test engineering.

[0030] When the seabed in-situ sampling experiment is performed, the operator controls the drilling device 2 to work through the control system 14, drives the drill rod 1 to axially extend outward and collect the seabed rock sample, the collected rock sample is transported into the sample cavity 21 through the hollow drill rod 1, the sample cavity 21 is isolated from the drill rod 1 by the control switch 6, so that the rock sample is kept water, gas and pressure, and the true sampling is ensured, after the sampling is completed, the control system 14 can automatically control the hydraulic system 15, the hydraulic system 15 controls the pressure cylinders 19 and the hydraulic cylinders 17 to respectively apply pressure to the sample cavity 21 and the confining pressure cavity 8, so that the underwater triaxial compression experiment can be performed, the control system 14 can record the mechanical parameters in real time, and the effect of the in-situ sampling and the mechanical property experiment is realized.

[0031] Preferably, the drilling device 2 comprises a rotor motor 23 and a rotating sleeve 5 which is drivingly connected with the rotor motor 23 through a gear assembly 22, the drill rod 1 is threadedly arranged in the rotating sleeve 5, the top end of the rotating sleeve 5 is communicated with the sample cavity 21, and the control switch 6 is arranged between the rotating sleeve 5 and the sample cavity 21.

[0032] The drill rod 1 is arranged inside the rotating sleeve 5. The rotor motor 23 drives the rotating sleeve 5 to rotate through the gear assembly 22. Under the action of the threaded structure, the drill rod 1 extends and retracts axially within the rotating sleeve 5, thereby realizing drilling and cutting of seabed rocks and mud samples. The rotor motor 23, gear assembly 22 and rotating sleeve 5 are all common mechanisms, which simplifies the specific structure of the drilling device 2.

[0033] Preferably, the bottom of the experimental body is provided with a casing 20 extending to the outside. The drilling device 2 and the drill rod 1 are both arranged inside the casing 20. A resistance sensor 3 is provided on the outer wall of the portion of the casing 20 located outside the experimental body. The resistance sensor 3 is used to detect the resistance during the drilling process. The resistance sensor 3 is electrically connected to the control system 14.

[0034] The casing 20 provides space for the arrangement of the drilling rig 2 and drill pipe 1, and also protects the drilling rig 2 during drilling. The resistance sensor 3 can detect the end resistance and sidewall friction during drilling. The magnitude of the end resistance and sidewall friction can reflect the hardness of the formation. In addition, by measuring the end resistance and sidewall friction, the physical properties of the collected geological samples, such as density, compressive strength, and fracture toughness, can be determined. This information can help in subsequent mechanical property studies.

[0035] Preferably, a temperature sensor 4 and a pore water pressure sensor 16 are also provided on the outer wall of the portion of the sleeve 20 located outside the experimental body. Both the temperature sensor 4 and the pore water pressure sensor 16 are electrically connected to the control system 14. The temperature sensor 4 is used to detect the seabed temperature, and the pore water pressure sensor 16 is used to detect the pore water pressure of the seabed rocks.

[0036] Temperature sensor 4 and pore water pressure sensor 16 can detect and record the temperature and pore water pressure of the seabed rock in real time during the drilling process, and then transmit the temperature and pore water pressure to control system 14. Control system 14 can easily determine the changes in temperature and pore water pressure, and can easily determine the parameter changes during the test process, providing important reference for seabed drilling and underground shale gas extraction.

[0037] Preferably, the outer shell also has a constant temperature cavity 7 formed inside, which is located outside the confining pressure cavity 8. The seabed in-situ sampling experimental device also includes a constant temperature device 9 connected to the constant temperature cavity 7, which is used to deliver a constant temperature medium into the constant temperature cavity 7.

[0038] The constant temperature cavity 7 is arranged outside the confining pressure cavity 8, and the constant temperature device 9 can deliver constant temperature medium at a certain temperature into the constant temperature cavity 7 to provide a constant temperature environment, heat preservation for the sample, control the environmental temperature of the sample, and thus maximize the fidelity of the seabed sampling. The constant temperature cavity 7 has a heat preservation layer to ensure that the temperature of the constant temperature medium in the constant temperature cavity 7 is constant. The heat preservation layer is located between the constant temperature cavity 7 and the confining pressure cavity 8. The constant temperature cavity 7 and the confining pressure cavity 8 are independent of each other, so that the temperature and the confining pressure cavities are located in different chambers and do not interfere with each other, and the original state of the sample can be maintained to the maximum extent.

[0039] Preferably, the constant temperature device 9 comprises a heating pipe 25 for heating the constant temperature medium and a pressure cylinder 24 for driving the flow of the constant temperature medium. The heating pipe 25 and the pressure cylinder 24 are electrically connected with the control system 14.

[0040] The control system 14 can control the pressure cylinder 24 to deliver the constant temperature medium into the constant temperature cavity 7. The heating pipe 25 can heat the liquid to adjust the temperature of the constant temperature medium, so that the environmental temperature in the constant temperature cavity 7 is always at a set value. The constant temperature device 9 is also provided with a temperature sensor connected with the control system 14 to control the set temperature for applying a constant temperature to the sample. The heating pipe 25 and the pressure cylinder 24 are used to adjust the temperature and flow of the constant temperature medium, and the structure is mature and simple.

[0041] Preferably, the pressure gauge 10 and the flow meter 11 are arranged on the pipeline between the constant temperature device 9 and the constant temperature cavity 7 and on the pipeline between the hydraulic oil cylinder 17 and the confining pressure cavity 8.

[0042] The pressure gauge 10 and the flow meter 11 can detect the pressure and flow of the constant temperature medium and the pressurized liquid, and transmit the pressure data and flow data to the control system 14 in real time, so that the control system 14 can record the relevant parameters and control the pressure and flow to be at a set value to realize programmed control.

[0043] Preferably, the upper part of the experimental main body is also provided with a counterweight device 18 for keeping the experimental main body balanced during sampling.

[0044] The counterweight device 18 is located at the upper part of the experimental main body to ensure the balance of the experimental main body during sampling and avoid tilting of the experimental main body during sampling. Specifically, the counterweight device 18 is a conical metal piece sleeved on the top of the experimental main body.

[0045] Preferably, the positioning device 12 is arranged at the top of the experimental main body.

[0046] The positioning device 12 can determine the position coordinates of the sample, accurately position the sampling process, and make the sampling position more accurate.

[0047] Preferably, the cooling device 13 is further included, and the cooling device 13 is used for cooling the hydraulic oil, and the cooling device 13 is electrically connected with the control system 14.

[0048] The cooling device 13 is used for cooling the hydraulic oil, and the hydraulic oil includes the hydraulic oil of the pressurizing oil cylinder 19 and the hydraulic oil cylinder 17, so that the hydraulic oil is prevented from being in a high-temperature state for a long time. In the embodiment, the cooling device 13 is a cooling oil machine, the cooling oil machine is communicated with each oil cylinder through a pipeline, the hydraulic oil is circulated into the cooling oil machine to be cooled, and then each oil cylinder is cooled.

[0049] The working process of the present application is as follows: when the seabed in-situ sampling experiment device is used, a suitable position is selected first, and then the coordinate point is determined, the seabed in-situ sampling experiment device is connected with the mechanical arm of the dredger, the hydraulic device, the cooling device 13 and the control system 14 are turned on, the mechanical arm is driven to drill after the position is positioned; the end resistance and the sidewall friction resistance in the drilling process can be measured by the resistance sensor 3, the change of the pore water pressure of the sample can be detected by the pore water pressure sensor 16, the temperature of the taken sample can be measured by the temperature sensor 4, and the control system 14 records the above data in real time during the drilling process.

[0050] During the drilling process, the drilling device 2 drives the drill rod 1 to move axially through the gear assembly 22, the drill rod 1 drills and cuts the rock or seabed mud sample, the sample enters the hollow drill rod 1, the control switch 6 is automatically turned on, the sample is pressed into the sample cavity 21, then the control switch 6 is turned off, and the sample collection operation is completed.

[0051] The pressure cylinder 24 in the constant-temperature device 9 acts to inject the constant-temperature medium at a certain temperature into the constant-temperature cavity 7, the temperature set is the temperature of the sample recorded by the temperature sensor 4, so that the sample can be kept at the same temperature as the seabed after being taken; then the hydraulic system 15 controls the hydraulic oil cylinder 17 to inject the hydraulic oil into the confining pressure cavity 8 to provide a constant confining pressure for the sample, and then the drilling device 2 is turned off.

[0052] When the triaxial compression experiment is needed, the seabed in-situ sample can be subjected to the conventional triaxial test or the triaxial test under dynamic stress on the seabed or in the laboratory. After the control system 14 is completed, the hydraulic system 15 is sent an instruction, the pressurizing oil cylinder 19 and the hydraulic oil cylinder 17 provide a set axial pressure and confining pressure for the sample to perform the experiment, and the cooling device 13 cools the hydraulic oil.

[0053] In summary, the embodiment of the present application provides a seabed in-situ sampling experiment device, a sample cavity and a confining pressure cavity are arranged in the shell of the experiment main body, a drill rod and a drilling device are arranged at the bottom of the experiment main body, when the seabed in-situ sampling experiment is carried out, the operator controls the drilling device to work through the control system, drives the drill rod to extend axially and collects seabed rock samples, the collected rock samples are transported into the sample cavity through the hollow drill rod, the control switch is used to isolate the sample cavity and the drill rod, so that the rock samples are kept water, gas and pressure, and the fidelity sampling is ensured, after the sampling is completed, the control system can automatically control the hydraulic system, the hydraulic system controls the pressurizing oil cylinder and the hydraulic oil cylinder to apply pressure to the sample cavity and the confining pressure cavity respectively, the underwater triaxial compression experiment can be carried out, the control system can record the mechanical parameters in real time, and the effect of in-situ sampling for mechanical property experiment is realized.

[0054] The above only describes the preferred embodiments of the present application, and it should be noted that those skilled in the art can make several improvements and replacements without departing from the technical principles of the present application, and these improvements and replacements should also be considered as the protection scope of the present application.

Claims

1. An in-situ seabed sampling apparatus, characterised in that, The experimental main body comprises a shell, the inside of the shell is successively formed with a sample cavity for accommodating a sample and a confining pressure cavity for applying confining pressure to the sample cavity from inside to outside, the top of the experimental main body is provided with a pressurizing oil cylinder for applying axial hydraulic pressure to the sample in the sample cavity, the hydraulic oil cylinder is communicated with the confining pressure cavity to apply hydraulic pressure to the confining pressure cavity, the hydraulic oil cylinder and the pressurizing oil cylinder are electrically connected with the hydraulic system, and the hydraulic system is electrically connected with the control system. The bottom of the experimental main body is also movably provided with a hollow drill rod and a drilling device in transmission connection with the drill rod, the drilling device is used for driving the drill rod to axially extend and retract to drill a sample, the top end of the drill rod is communicated with the sample cavity, and the bottom end of the sample cavity is provided with a control switch for opening or closing the sample cavity, and the control switch and the drilling device are electrically connected with the control system.

2. The subsea in situ sampling laboratory of claim 1, wherein, The drilling device comprises a rotor motor and a rotating sleeve in transmission connection with the rotor motor through a gear assembly, the drill rod is screwedly assembled in the rotating sleeve, the top end of the rotating sleeve is communicated with the sample cavity, and the control switch is arranged between the rotating sleeve and the sample cavity.

3. The subsea in situ sampling laboratory of claim 2, wherein, The bottom of the experimental main body is provided with a sleeve extending to the outside, the drilling device and the drill rod are arranged in the sleeve, a resistance sensor is arranged on the outer wall of the part of the sleeve located outside the experimental main body, the resistance sensor is used for detecting resistance in the drilling process, and the resistance sensor is electrically connected with the control system.

4. The subsea in situ sampling laboratory of claim 3, wherein, A temperature sensor and a pore water pressure sensor are also arranged on the outer wall of the part of the sleeve located outside the experimental main body, the temperature sensor and the pore water pressure sensor are electrically connected with the control system, the temperature sensor is used for detecting seabed temperature, and the pore water pressure sensor is used for detecting pore water pressure of seabed rock.

5. The in situ seabed sampling laboratory apparatus of any of claims 1-4, wherein, The inside of the shell is also formed with a constant-temperature cavity, the constant-temperature cavity is located outside the confining pressure cavity, and the seabed in-situ sampling experimental device further comprises a constant-temperature device communicated with the constant-temperature cavity, and the constant-temperature device is used for conveying constant-temperature medium into the constant-temperature cavity.

6. The subsea in situ sampling laboratory of claim 5, wherein, The constant-temperature device comprises a heating pipe for heating constant-temperature medium and a pressure cylinder for driving the flow of constant-temperature medium, and the heating pipe and the pressure cylinder are electrically connected with the control system.

7. The subsea in situ sampling laboratory of claim 6, wherein, A pressure gauge and a flowmeter are further arranged on the pipeline between the constant-temperature device and the constant-temperature cavity and on the pipeline between the hydraulic oil cylinder and the confining pressure cavity.

8. The in situ seabed sampling laboratory apparatus of any of claims 1-4, wherein, The upper part of the experimental main body is further provided with a counterweight device, and the counterweight device is used for keeping the experimental main body balanced during sampling.

9. The in situ seabed sampling laboratory apparatus of any of claims 1-4, wherein, A positioning device is further arranged on the top of the experimental main body.

10. The in situ seabed sampling apparatus of any one of claims 1 to 4, wherein, A cooling device is further arranged, and the cooling device is used for cooling hydraulic oil, and the cooling device is electrically connected with the control system.

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