Rock core sample in-situ parameter testing device for deep sea underground electric coring tool

Abstract

The invention relates to a rock core sample in-situ parameter testing device for a deep sea underground electric coring tool, which comprises a testing cabin body, a piston, an outer cylinder, a first driving assembly, a second driving assembly, a plugging sliding sleeve and a testing probe, and the outer cylinder comprises a sealing end and an opening end; the testing cabin is arranged in the outer cylinder, fluid channels are formed in the side walls of the testing cabin and the outer cylinder respectively, the plugging sliding sleeve is slidably arranged on the outer side of the testing cabin, and the second driving assembly is in driving connection with the plugging sliding sleeve and used for controlling opening and closing of the fluid channels; the opening end of the test cabin body is communicated with the opening end of the outer cylinder through a ball valve; the test probe is arranged in the test cabin body and is used for adjusting the internal temperature of the test cabin body and measuring parameters of the rock core sample; the piston is slidably arranged at the sealed end of the outer cylinder, is in driving connection with the first driving assembly, and is used for adjusting the internal pressure of the test cabin. Compared with the prior art, the method has the advantages that test data are more practical, the test process is simplified, and more time and labor are saved.

Description

Technical Field

[0001] This invention relates to the field of hydrate core testing technology, and in particular to an in-situ parameter testing device for core samples used in deep-sea downhole electric coring tools. Background Technology

[0002] Currently, the exploration has revealed abundant natural gas hydrates in the sea area. Due to their extremely high energy density and cleanliness, they are widely regarded as the most promising clean energy source in the 21st century. Their rational development and utilization are of great significance to the country's energy security.

[0003] Natural gas hydrates are cage-like solids formed by the combination of methane and other natural gas molecules with water molecules under low temperature and high pressure conditions on the seabed. They are found in hydrate core sediments. Under high temperature and low pressure conditions, they decompose to release methane gas. Generally, extraction is carried out by depressurizing or heating to decompose the hydrates. However, during the decomposition process, the strength of the hydrate sediments decreases, which can easily lead to large-scale seabed landslides due to soil loosening. Therefore, studying the physical parameters of hydrate core samples and the decomposition and release patterns under depressurization and heating is of great guiding significance for the safe and effective utilization of natural gas hydrates in the future.

[0004] Currently, tests on the decomposition of natural gas hydrates primarily rely on artificially synthesized core samples, resulting in discrepancies between the test data and those obtained from real hydrate samples. A small number of tests utilize core samples obtained from the deep sea, which are then integrated with testing devices. For example, invention publication CN106324217A discloses a conventional physical property testing device for bioherm cores based on miniature samples. This testing device includes: a conventional physical property testing device for bioherm cores based on miniature samples, a permeability testing device, a porosity measuring device, a booster pump, a soap film flow meter, a pressure gauge, and a switch. The conventional physical property testing device for bioherm cores based on miniature samples includes a cylinder, a rubber sleeve, rubber sleeve end plugs, a cylinder plug, a cylinder cap, and a sealing assembly. The cylinder has a hollow structure, with the rubber sleeve and rubber sleeve end plugs located inside. The rubber sleeve is used to hold the core sample. The rubber sleeve end plugs are embedded at both ends of the rubber sleeve and are in direct contact with the core sample. However, the core samples will experience pressure and temperature losses during the process of being retrieved from the seabed and docked with the core testing device. They are not completely authentic samples and cannot maintain the original state of the core samples, resulting in distorted test data.

[0005] In summary, existing deep-sea downhole coring and testing technologies suffer from difficulties in in-situ parameter testing of core samples, low testing accuracy, and insufficient system integration, leading to easily distorted test data that is of little significance for subsequent legal examinations. Summary of the Invention

[0006] The purpose of this invention is to overcome the shortcomings of the prior art, such as difficulty in testing in-situ parameters of core samples, low testing accuracy, poor discrepancy between test data and actual conditions, and limited reference value, and to provide a device for testing in-situ parameters of core samples for deep-sea downhole electric coring tools.

[0007] The objective of this invention can be achieved through the following technical solutions: A core sample in-situ parameter testing device for a deep-sea downhole electric coring tool includes a test chamber, a piston, an outer cylinder, a first drive assembly, a second drive assembly, a sealing sleeve, and a test probe. The outer cylinder includes a sealed end and an open end. The test chamber is housed inside the outer cylinder, and fluid channels are provided on the side walls of both the test chamber and the outer cylinder. The sealing sleeve is slidably disposed on the outside of the test chamber. The second drive assembly drives and connects to the sealing sleeve to control the opening and closing of the fluid channels. The open end of the test chamber is connected to the open end of the outer cylinder via a ball valve. The test probe is installed inside the test chamber to adjust the internal temperature of the test chamber and measure the parameters of the core sample. The piston is slidably disposed at the sealed end of the outer cylinder and drives and connects to the first drive assembly to adjust the internal pressure of the test chamber.

[0008] Preferably, the first drive assembly includes an electronically controlled cabin end cover, a piston screw, a first motor support, a first bearing, a first frameless motor, and a screw nut; The end cap of the electrical control chamber is installed inside the outer cylinder, and the piston and the test chamber are located on both sides of the end cap of the electrical control chamber. The first motor support is fixed on the side of the end cap of the electrical control chamber away from the piston. The first bearing and the first frameless motor are coaxially installed in the first motor support. The lead screw nut is rotatably installed in the inner ring of the first bearing and drives the first frameless motor. One end of the piston lead screw is connected to the piston, and the other end is threaded to the lead screw nut.

[0009] Preferably, the outer side of the end cap of the electronic control chamber is fitted with a sealing rubber ring, and a connecting rod is provided on the side near the test chamber. The connecting rod has a connecting pipe inside, which is used to connect the space where the piston is located with the outside of the test chamber.

[0010] Preferably, there are multiple connecting rods, which are symmetrically distributed around the first motor support.

[0011] Preferably, the second drive assembly includes a second inner frameless motor, a second bearing, a drive rotating sleeve, an inner support cylinder, and a drive connecting rod shaft; The inner support cylinder is coaxially mounted on the side of the first motor support seat near the test chamber. The second inner rotating frameless motor and the second bearing are mounted on the inner support cylinder. The drive rotating sleeve is rotatably disposed on the outside of the second bearing and drives the second inner rotating frameless motor. The outer side of the drive rotating sleeve is provided with a wavy guide groove that undulates along the axial direction. One end of the drive connecting rod shaft is slidably disposed in the wavy guide groove, and the other end is connected to the sealing sleeve for adjusting the sealing sleeve along the axial direction of the test chamber.

[0012] Preferably, the sealing sleeve includes an outer cylinder sealing sleeve, a sleeve connecting rod, and a test chamber sealing sleeve connected in sequence; The outer cylinder sealing sleeve is connected to the drive connecting rod shaft, the outer wall of the outer cylinder sealing sleeve abuts against the inner wall of the outer cylinder, and a sealing ring is provided on the outer side of the outer cylinder sealing sleeve; The inner wall of the sealing sleeve of the test chamber abuts against the outer wall of the test chamber, and a sealing ring is provided on the inner side of the sealing sleeve of the test chamber.

[0013] Preferably, the second drive assembly further includes a connecting plate, which is fixed to the side of the inner support cylinder away from the first motor support seat, and one end of the test chamber is fixed to the connecting plate.

[0014] Preferably, the ball valve includes an upper end cover, a stem, a lower end cover, and a body. The ball valve body is installed on one end of the test chamber near the opening of the outer cylinder via an upper ball valve cover and a lower ball valve cover. The ball valve stem is coaxially arranged along the rotation axis of the ball valve body, and the ball valve stem is connected to the second drive assembly.

[0015] Preferably, the second drive assembly further includes a ball valve drive shaft, one end of which is connected to the ball valve stem and the other end is connected to the ball valve.

[0016] Preferably, the test probe is used to measure the temperature, resistivity, acoustic wave and geotechnical parameters of the core sample, and to heat the internal environment of the test chamber.

[0017] Compared with the prior art, the present invention has the following advantages: (1) In this scheme, the ball valve and fluid channel can be opened to collect core samples based on static pressure. The parameters of the core samples are collected through the test probe. The sliding sleeve is closed to form a sealed environment in the test chamber. By adjusting the temperature and pressure, the environment inside the test chamber can be simulated and controlled, and the in-situ simulation test of the core samples can be realized. Thus, in-situ acquisition of various parameters such as temperature, geotechnical parameters, resistivity, and acoustic characteristics of the core samples and in-situ depressurization heating decomposition tests can be realized in the limited space downhole. The real physical state of the core samples can be recorded in real time during the core sampling process, avoiding pressure and temperature disturbances and information loss caused by traditional core sampling, lifting, and testing methods, and significantly improving the authenticity and fidelity of the test data. At the same time, it has the function of real-time data transmission and recording, which can significantly improve the intelligence and informatization level of deep-sea core sampling operations and provide high-precision in-situ data support for subsequent core sample analysis and seabed strata characteristic evaluation.

[0018] (2) The deep-sea electric coring equipment on which this scheme is based adopts a dual-tube single-action design. The testing device is placed at the top of the inner tube. During the coring process, as the core continuously enters the inner sampling tube, it enters the testing chamber. During entry, the core will come into contact with various sensor probes to acquire parameters such as geomechanical parameters, temperature, and acoustic characteristics. After the coring work is completed, the ball valve is closed to form a closed and sealed environment. The natural gas hydrate core is depressurized and heated to decompose it, thereby conducting in-situ testing. The device adopts a modular and miniaturized design, has a compact structure, can be efficiently coupled with the deep-sea electric coring system, and has good installation compatibility and engineering adaptability. Attached Figure Description

[0019] Figure 1 A schematic diagram of the external appearance of the in-situ parameter testing device for core samples provided by the present invention; Figure 2 This is a cross-sectional view of the in-situ parameter testing device for core samples provided by the present invention. Figure 3 A schematic diagram of the internal structure of the outer cylinder of the in-situ parameter testing device for core samples provided by the present invention; In the diagram: 1. Upper end cover, 2. Test chamber, 3. Piston, 4. Piston screw, 5. Electrically controlled chamber end cover, 6. Connecting rod, 7. First motor support seat, 8. First bearing, 9. First internal rotating frameless motor, 10. Screw nut, 11. Power supply, 12. Second internal rotating frameless motor, 13. Drive rotating sleeve, 14. Inner support cylinder, 15. Connecting disc, 16. Outer cylinder sealing sleeve, 17. Test chamber body, 18. Sleeve connecting shaft, 19. First test chamber sealing sleeve, 20. Test probe, 21. Second test chamber sealing sleeve, 22. Ball valve drive shaft, 23. Ball valve upper end cover, 24. Ball valve stem, 25. Ball valve lower end cover, 26. Ball valve body, 27. Lower end cover, 28. Second bearing, 29. Sealing sleeve connecting rod, 30. Outer cylinder, 31. Drive connecting rod shaft. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0021] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0022] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0023] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the product of this invention is usually placed during use. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0024] It should be noted that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0025] Furthermore, terms such as "horizontal" and "vertical" do not imply that components must be absolutely horizontal or suspended, but rather that they can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal than "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0026] Example 1 like Figures 1 to 3 As shown, this embodiment provides a core sample in-situ parameter testing device for deep-sea downhole electric coring tools, which is suitable for deep-sea coring operations within the deep sea depth and can realize in-situ multi-parameter measurement and environmental simulation control of core samples.

[0027] The main body of the device includes an outer cylinder 30, a test chamber 2, a piston 3, a first drive assembly, a second drive assembly, a sealing sleeve, and a test probe 20. The outer cylinder 30 is made of 316L stainless steel and is a cylindrical structure with openings at both ends. Its upper end is sealed by a flange, and its lower end is an open end for connection with the core sampling tool. The test chamber 2 is coaxially positioned inside the outer cylinder 30. Four fluid channels are evenly distributed along the circumference of the side wall of the test chamber 2, and four corresponding fluid channels are formed in the outer cylinder 30. The fluid channels of the two components are initially aligned and connected. The sealing sleeve is fitted onto the outside of the test chamber 2 and has a clearance fit with the inner wall of the outer cylinder 30. It is driven by the second drive assembly to slide axially, thus opening and closing the fluid channels. The lower end of the test chamber 2, near the opening of the outer cylinder, is connected to the opening of the outer cylinder 30 via a ball valve, allowing core samples to enter the test chamber 2 through the ball valve. The test probe 20 is fixedly installed on the inner wall of the test chamber 2, and the piston 3 is coaxially arranged inside the sealed end of the outer cylinder 30. It is driven by the first drive assembly to slide axially to adjust the internal pressure of the test chamber 2.

[0028] In this embodiment, as Figure 2As shown, the first drive assembly includes an electrical control chamber end cap 5, a piston screw 4, a first motor support 7, a first bearing 8, a first frameless motor 9, and a screw nut 10. The electrical control chamber end cap 5 is coaxially mounted inside the outer cylinder 30, dividing the interior of the outer cylinder 30 into upper and lower cavities. The piston 3 is located in the sealed cavity above the electrical control chamber end cap 5, and the test chamber 2 is located below the electrical control chamber end cap 5. An annular groove is formed on the outer circumference of the electrical control chamber end cap 5, with a built-in fluororubber sealing ring to achieve a static seal with the inner wall of the outer cylinder 30. Two connecting rods 6 are welded and fixed to the side of the electrical control chamber end cap 5 near the test chamber 2. The two connecting rods 6 are symmetrically distributed on both sides of the first motor support 7. Each connecting rod 6 has an axially extending connecting pipe inside, used to connect the sealed cavity where the piston 3 is located with the outer space of the test chamber 2, allowing the outlet of gas generated during the core sample testing process in the test chamber 2.

[0029] Furthermore, the first motor support 7 is a cylindrical aluminum alloy shell, which is bolted to the side of the electrical control compartment end cover 5 away from the piston 3; the first bearing 8 is a deep groove ball bearing, and the first frameless motor 9 is an internal rotating structure, both of which are coaxially installed in the internal cavity of the first motor support 7. The lead screw nut 10 adopts a trapezoidal thread structure, and its outer ring is interference-fitted with the inner ring of the first bearing 8. One end of the lead screw nut 10 is connected to the output shaft of the first frameless motor 9 through a flat key to achieve synchronous rotation. The upper end of the piston screw 4 is coaxially fixed to the piston 3 by an internal hexagon screw, and the lower end passes through the central through hole of the electrical control compartment end cover 5 and is threadedly engaged with the lead screw nut 10 to form a helical transmission pair.

[0030] In this embodiment, as Figure 2 and Figure 3 As shown, the second drive assembly includes a second inner frameless motor 12, a second bearing 28, a drive rotating sleeve 13, an inner support cylinder 14, a drive connecting rod shaft 31, a connecting plate 15, and a ball valve drive shaft 22. The inner support cylinder 14 is a cylindrical piece of stainless steel, coaxially mounted on the side of the first motor support seat 7 near the test chamber 2, with its upper end fixedly connected to the first motor support seat 7 by bolts. The second inner frameless motor 12, with parameters identical to the second bearing 28, is mounted on the outer side of the middle of the inner support cylinder 14. Two second bearings, using angular contact ball bearings, are mounted on the outer sides of the upper and lower ends of the inner support cylinder 14, respectively. The inner wall of the drive rotating sleeve 13 is interference-fitted with the outer ring of the second bearing 28, and the upper end of the drive rotating sleeve 13 is connected to the output shaft of the second inner frameless motor 12 via a flat key, allowing it to rotate around its axis. Two wavy guide grooves are circumferentially formed on the outer wall of the drive rotating sleeve 13. It should be understood that more than two fluid channels can be provided along the axial direction on the test chamber 2, and corresponding second test chamber sealing sleeves 21 can be configured and connected by sealing sleeve connecting rods 29, so that each sealing sleeve moves synchronously and controls the overall sealing performance of the test chamber 2.

[0031] Furthermore, the connecting plate 15 adopts a circular stainless steel flange, which is bolted to the lower end of the inner support cylinder 14 away from the first motor support seat 7. The upper end of the test chamber 2 is coaxially fixed to the lower surface of the connecting plate 15 by bolts, thereby achieving the suspension support of the test chamber 2. There are two drive linkage shafts 31 in total. Both ends of each drive linkage shaft 31 are equipped with spherical bearings. The upper end is embedded in the wave-shaped guide groove of the drive rotating sleeve 13 with clearance fit, and the lower end is hinged to the sealing sleeve. Under the constraint of the guide groove, the rotational motion of the drive rotating sleeve 13 can be converted into axial linear motion, thereby driving the sealing sleeve to slide.

[0032] In this embodiment, as Figure 3 As shown, the sealing sleeve includes an outer cylinder sealing sleeve 16, a sleeve connecting rod 18, and a test chamber sealing sleeve 19 connected in sequence. The outer wall of the outer cylinder sealing sleeve 16 is clearance-fitted with the inner wall of the outer cylinder 30, and two annular grooves are formed on the outer circumferential side of the outer cylinder sealing sleeve 16, housing fluororubber sealing rings. The upper surface of the outer cylinder sealing sleeve 16 is hinged to the lower end of the drive connecting rod shaft 31 via a pin, and moves axially synchronously with the drive connecting rod shaft 31.

[0033] The sliding sleeve connecting rod 18 consists of two stainless steel rods symmetrically distributed on both sides of the test chamber 2. Its upper end is welded and fixed to the outer cylinder sealing sliding sleeve 16, and its lower end is welded and fixed to the test chamber sealing sliding sleeve 19. The test chamber sealing sliding sleeve 19 has an annular structure, with its inner wall fitting tightly against the outer wall of the test chamber 2. Two annular grooves are formed on its inner circumference, housing a fluororubber sealing ring, which can seal the fluid channels on the side wall of the test chamber 2 during sliding.

[0034] In this embodiment, as Figure 2 As shown, the ball valve includes an upper ball valve cover 23, a ball valve stem 24, a lower ball valve cover 25, and a ball valve body 26. The ball valve body 26 is made of stainless steel, and its upper end is secured by the upper ball valve cover 23, and its lower end by the lower ball valve cover 25; the three are fastened together with bolts. The upper surface of the upper ball valve cover 23 is fixedly connected to the lower end of the test chamber 2 by bolts, and the lower surface of the lower ball valve cover 25 is aligned with the open flange of the outer cylinder 30 for connection to the inner tube assembly of the coring tool. The ball valve stem 24 is coaxially arranged along the rotation axis of the ball valve body 26, and its upper end extends to the outside of the upper cover 23 of the ball valve. It is connected to the lower end of the ball valve drive shaft 22 by a flat key. The upper end of the ball valve drive shaft 22 is fixedly connected to the lower end of the test chamber sealing sleeve 19 by a coupling. When it moves axially synchronously with the sealing sleeve, it drives the ball valve stem 24 to rotate, thereby realizing the opening and closing of the ball valve body 26.

[0035] In this embodiment, four sets of test probes 20 are circumferentially and uniformly fixed to the inner wall of the test chamber 2, with adjacent probes at a 90° angle. The temperature sensor of the test probe 20 is a PT100 type, with a measurement range of -50~200℃ and an accuracy of ±0.1℃. It also has a heating function with a heating power of 500W and a temperature adjustment range of -20~150℃. The resistivity electrode is made of titanium alloy, with an electrode spacing of 30mm and a measurement range of 0.1~1000Ω・m. The ultrasonic transducer has a center frequency of 1MHz and measures the sound wave propagation speed in the range of 1000~6000m / s. The geotechnical parameter sensor is a strain gauge type, with a measurement range of 0~60MPa and an accuracy of ±0.5%FS, which can monitor parameters such as pore pressure and contact pressure of the rock core. The signal cables of all test probes 20 are led out through the sealed wiring holes on the side wall of the test chamber 2 and connected to the built-in intelligent control unit.

[0036] Specifically, the upper cover 1 is bolted to the test chamber 2 and sealed with an O-ring. The piston 3 is placed on top of the test chamber 2 and connected to the piston screw 4. The piston screw 4 engages with the screw nut 10 and is housed within the first bearing 8 and the first internal frameless motor 9, with the first motor support 7 on its exterior. The first motor support 7 is bolted to the inner support cylinder 14, and a second internal frameless motor 12 and a second bearing 28 are located on its exterior, housed inside the drive rotating sleeve 13. Two connecting rods 6 are symmetrically distributed and have internal channels. Their lower parts pass through the outer cylinder sealing sleeve 16, which is connected to the first test chamber sealing sleeve 19 via a sleeve connecting shaft 18.

[0037] Furthermore, the test chamber is bolted to the connecting plate, and internally equipped with test probes (replaceable for temperature, geotechnical parameters, heating, etc.). Fluid channels are provided on the side walls. The first and second test chamber sealing sleeves are connected by a sealing sleeve connecting rod. The second test chamber sealing sleeve is connected to the ball valve stem via a ball valve drive shaft. The ball valve body is located between the upper and lower end covers of the ball valve, and the lower end cover is bolted to the lower end of the lower end cover. One end of the drive connecting rod shaft is placed inside a groove on the outer wall of the drive rotating sleeve, and the other end is connected to the outer cylinder sealing sleeve.

[0038] Specifically, in deep-sea coring operations, the electric coring system employs a dual-tube, single-action structure. During drilling, the outer tube rotates and advances, while the inner tube remains stationary to protect the core. Once the drill bit enters the target formation, the core sample enters the inner tube sampling chamber under hydrostatic pressure and gradually penetrates into the test chamber body 17. During the core's entry, the core surface sequentially contacts the test probes 20 installed on the inner wall of the chamber. Sensors integrated on the test probes 20 collect data such as temperature, pore pressure, acoustic wave propagation characteristics, and resistivity in real time, enabling synchronous measurement of the core sample under in-situ formation conditions.

[0039] After the coring process is completed, the second inner frameless motor 12 is driven to rotate the drive rotating sleeve 13. Utilizing the design of the wave-shaped guide groove, the drive connecting rod shaft 31 moves downwards, thereby driving the outer cylinder sealing sleeve 16, the first test chamber sealing sleeve 19, and the second test chamber sealing sleeve 21 downwards, closing the fluid channels on the side walls of the outer cylinder 30 and the test chamber 2. Simultaneously, the ball valve drive shaft 22 drives the ball valve stem 24 to close the ball valve body 26, thus achieving a sealed test chamber and isolating it from the external fluid environment.

[0040] At this time, the piston 3 inside the chamber moves through the piston screw 4, and in conjunction with the channel in the connecting rod 6, adjusts the internal pressure of the test chamber 2. The test probe 20 can be heated to achieve the simulation and control of the environment inside the test chamber, and the generated gas can enter the top of the test device through the channel in the connecting rod.

[0041] For testing natural gas hydrate core samples, this invention induces hydrate decomposition within a sealed chamber through depressurization or heating. Internal sensors monitor parameters such as temperature changes, gas generation rate, and acoustic response in real time during the decomposition process, enabling in-situ decomposition testing of the hydrate core sample. The entire process is completed within a sealed chamber, avoiding distortion caused by temperature and pressure changes after the sample is brought to the ground.

[0042] Specifically, the testing steps for this device are as follows: The device is assembled with the dual-tube single-action structure of the deep-sea electric coring tool. The outer cylinder 30 is fixed to the outer tube of the coring tool, and the test chamber 2 and its internal components are fixed to the inner tube of the coring tool. During coring operations, the outer tube drives the drill bit to rotate and advance, while the inner tube remains stationary to protect the core. After the drill bit penetrates the target formation, the core sample, under the static pressure of the formation, passes sequentially through the ball valve body 26 and the opening end of the test chamber 2, entering the interior of the test chamber 2.

[0043] At this time, the fluid channel between the test chamber 2 and the outer cylinder 30 is open, and the chamber is connected to the external seawater environment to maintain in-situ pressure balance. During the advancement of the core sample in the chamber, its surface comes into contact with the four sets of test probes 20 in sequence, and each probe is activated synchronously: the temperature sensor collects the in-situ temperature of the core, the resistivity electrode measures the conductivity of the core, the ultrasonic transducer emits and receives sound wave signals to calculate the propagation speed, and the geotechnical parameter sensor monitors the interaction force between the core and the chamber wall. All data are collected in real time through the intelligent control unit and transmitted to the sea surface control console via the umbilical cable to realize the synchronous measurement of multiple parameters of the core in situ.

[0044] When core sampling is completed, the second inner frameless motor 12 starts, driving the drive rotating sleeve 13 to rotate clockwise around its axis. Under the constraint of the wave-shaped guide groove, the drive connecting rod shaft 31 drives the outer cylinder sealing sleeve 16 to slide axially downwards. The outer cylinder sealing sleeve 16, through the sleeve connecting rod 18, drives the test chamber sealing sleeve 19 to move downwards synchronously until the sealing ring of the test chamber sealing sleeve 19 is tightly fitted against the outer wall of the test chamber 2, closing the fluid channel on the side wall of the test chamber 2. Simultaneously, the sealing ring of the outer cylinder sealing sleeve 16 is tightly fitted against the inner wall of the outer cylinder 30, closing the fluid channel of the outer cylinder 30. During this process, the test chamber sealing sleeve 19 drives the ball valve stem 24 to rotate 90° through the ball valve drive shaft 22, completely closing the ball valve body 26, achieving a double seal of the test chamber 2 and completely isolating it from the external seawater environment.

[0045] After sealing, if it is necessary to simulate the in-situ environment of the formation or conduct special tests, start the first frameless motor 9: the motor drives the lead screw nut 10 to rotate, and through the screw transmission, drives the piston lead screw 4 and piston 3 to move up and down along the axis to adjust the internal pressure of the test chamber 2; at the same time, the heating function of the test probe 20 is activated to adjust the temperature inside the chamber to the target value, so as to achieve accurate simulation of the temperature and pressure environment.

[0046] Gases generated during the test, such as natural gas hydrate decomposition gases, are led out through the connecting pipe inside the connecting rod 6 to the sealed cavity where the piston 3 is located, thus avoiding abnormal pressure inside the chamber. Each test probe 20 continuously collects the parameter changes of the core under the simulated environment, forming a complete test data curve, which provides a scientific basis for formation evaluation.

[0047] The preferred embodiments of the present invention have been described in detail above. It should be understood that those skilled in the art can make numerous modifications and variations based on the concept of the present invention without creative effort. Therefore, all technical solutions that can be obtained by those skilled in the art based on the concept of the present invention through logical analysis, reasoning, or limited experimentation on the basis of existing technology should be within the scope of protection defined by the claims.

Claims

1. A core sample in-situ parameter testing device for a deep-sea downhole electric coring tool, characterized in that, It comprises a test cabin (2), a piston (3), an outer cylinder (30), a first driving assembly, a second driving assembly, a blocking sliding sleeve and a test probe (20), the outer cylinder (30) comprises a sealed end and an open end; The test cabin (2) is arranged in the outer cylinder (30), and fluid channels are arranged on the side walls of the test cabin (2) and the outer cylinder (2) respectively, the blocking sliding sleeve is slidably arranged outside the test cabin (2), the second driving assembly is drivingly connected with the blocking sliding sleeve and used for controlling the opening and closing of the fluid channels, the open end of the test cabin (2) is communicated with the open end of the outer cylinder (30) through a ball valve, the test probe (20) is installed in the test cabin (2) and used for adjusting the internal temperature of the test cabin (2) and measuring the parameters of a core sample, and the piston (3) is slidably arranged at the sealed end of the outer cylinder (30) and drivingly connected with the first driving assembly and used for adjusting the internal pressure of the test cabin (2).

2. The core sample in-situ parameter testing device for the downhole electric core drilling tool in the deep sea of claim 1, characterized in that, The first driving assembly comprises an electric control cabin end cover (5), a piston lead screw (4), a first motor support seat (7), a first bearing (8), a first frameless motor (9) and a lead screw nut (10); The electric control cabin end cover (5) is installed in the outer cylinder (30), the piston (3) and the test cabin (2) are located on the two sides of the electric control cabin end cover (5), the first motor support seat (7) is fixed on the side of the electric control cabin end cover (5) away from the piston (3), the first bearing (8) and the first frameless motor (9) are coaxially installed in the first motor support seat (7), the lead screw nut (10) is rotatably installed in the inner ring of the first bearing (8) and drivingly connected with the first frameless motor (9), and one end of the piston lead screw (4) is connected with the piston (3) and the other end is threadedly connected with the lead screw nut (10).

3. The core sample in-situ parameter testing device for the downhole electric core drilling tool in the deep sea of claim 2, characterized in that, The outer side of the electric control cabin end cover (5) is sleeved with a sealing rubber ring, and the side close to the test cabin (2) is provided with a connecting rod (6), the connecting rod (6) is internally provided with a communication pipeline and used for communicating the space where the piston is located with the outside of the test cabin (2).

4. The core sample in-situ parameter testing device for the downhole electric core drilling tool in the deep sea of claim 2, characterized in that, The number of the connecting rods (6) is multiple, and they are symmetrically distributed around the first motor support seat (7).

5. The core sample in-situ parameter testing device for the downhole electric core taking tool in the deep sea of claim 2, characterized in that, The second driving assembly comprises a second inner-rotation frameless motor (12), a second bearing (28), a driving rotating sleeve (13), an inner support cylinder (14) and a driving connecting rod shaft (31); The inner support cylinder (14) is coaxially installed on the side of the first motor support seat (7) close to the test cabin (2), the second inner-rotation frameless motor (12) and the second bearing (28) are installed on the inner support cylinder (14), the driving rotating sleeve (13) is rotatably arranged on the outer side of the second bearing (28) and drivingly connected with the second inner-rotation frameless motor (12), the outer side of the driving rotating sleeve (13) is provided with a wave-shaped guide groove which undulates along the axial direction, one end of the driving connecting rod shaft (31) is slidably arranged in the wave-shaped guide groove, and the other end is connected with the blocking sliding sleeve and used for adjusting the blocking sliding sleeve along the axial direction of the test cabin (2).

6. The core sample in-situ parameter testing device for the downhole electric core taking tool in the deep sea of claim 5, characterized in that, The sealing sliding sleeve comprises an outer cylinder sealing sliding sleeve (16), a sliding sleeve connecting rod (18) and a test cabin sealing sliding sleeve (19) connected in sequence; The outer cylinder sealing sliding sleeve (16) is connected with a driving connecting rod shaft (31), the outer wall of the outer cylinder sealing sliding sleeve (16) abuts against the inner wall of the outer cylinder (30), and the outer side of the outer cylinder sealing sliding sleeve (16) is provided with a sealing ring; The inner wall of the test cabin sealing sliding sleeve (19) abuts against the outer wall of the test cabin (2), and the inner side of the test cabin sealing sliding sleeve (19) is provided with a sealing ring.

7. The core sample in-situ parameter testing device for the downhole electric core taking tool in the deep sea of claim 5, characterized in that, The second driving assembly further comprises a connecting disc (15) fixed on the side of the inner support cylinder (14) away from the first motor support base (7), and one end of the test cabin (2) is fixed on the connecting disc (15).

8. The core sample in-situ parameter testing device for the downhole electric core taking tool in the deep sea of claim 1, characterized in that, The ball valve comprises a ball valve upper end cover (23), a ball valve valve stem (24), a ball valve lower end cover (25) and a ball valve valve body (26); The ball valve valve body (26) is installed at one end of the test cabin (2) close to the opening end of the outer cylinder (30) through the ball valve upper end cover (23) and the ball valve lower end cover (25), the ball valve valve stem (24) is coaxially arranged along the rotation axis of the ball valve valve body (26), and the ball valve valve stem (24) is connected with the second driving assembly.

9. The core sample in-situ parameter testing device for the downhole electric core taking tool in the deep sea of claim 8, characterized in that, The second driving assembly further comprises a ball valve driving shaft (22), one end of the ball valve driving shaft (22) is connected, and the other end is connected with the ball valve valve stem (24).

10. The core sample in-situ parameter testing device for the downhole electric core taking tool in the deep sea of claim 1, characterized in that, The test probe (20) is used for measuring the temperature, resistivity, acoustic wave and geotechnical parameters of the core sample, and is used for heating the internal environment of the test cabin (2).

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