Static sounding device for deep-sea heat-preservation and pressure-preservation sediments

Abstract

The invention discloses a static sounding device for deep-sea heat-preservation and pressure-preservation sediments, which belongs to the technical field of static sounding testing of natural gas hydrate sediments and mainly comprises a deep-sea sediment sample heat-preservation and pressure-preservation cabin, a pressure cabin, a probe rod, a lead screw nut mechanism, a force sensor, a motor and a positioning and bearing unit. The deep-sea sediment sample heat-preservation and pressure-preservation cabin is a main body of a static sounding test and is used for filling a sample; the pressure chamber is filled with seawater, and the pressure of the pressure chamber is consistent with that of the deep-sea sediment sample heat-preservation and pressure-preservation chamber through the pressure adjusting unit; the motor realizes the penetration and pulling-out of the probe rod through a lead screw nut mechanism; and the force sensor is connected with a data acquisition instrument through a spring cable to complete data acquisition of the penetration force. Under the condition that the environment pressure and temperature are basically unchanged, the static sounding test of the deep-sea sediment is completed, and the related mechanical properties of the deep-sea sediment are accurately reflected.

Description

Technical Field

[0001] The invention relates to a static penetration device for deep-sea heat-insulating and pressure-maintaining sediments, belonging to the technical field of static penetration testing of natural gas hydrate sediments. Background Art

[0002] The rapid development of science and technology has led to an increasing demand for resources. Shallow surface resources are unable to meet the needs of sustained production, and resource extraction is moving deeper into the earth. In the field of deep-sea exploration, the successful extraction of natural gas hydrates will greatly ease the pressure of energy consumption.

[0003] Static penetration testing, as a reliable testing technology widely used in geotechnical engineering, uses mechanical force to push the probe rod equipped with the probe into the soil layer, and infers the basic physical and mechanical properties of the soil by measuring the penetration resistance of the soil. At present, China has achieved the thermal insulation and pressure sampling of hydrate sediments while maintaining the original field environment (temperature and pressure) of natural gas hydrates, but there is a lack of static penetration testing equipment for testing thermal insulation and pressure samples. Using static penetration testing to study the mechanical properties of deep-sea sediments is of great strategic significance to the exploitation and utilization of natural gas hydrates. Therefore, it is particularly necessary to establish a static penetration testing device for deep-sea thermal insulation and pressure sediments. Summary of the invention

[0004] The present invention provides a static penetration device for deep-sea heat preservation and pressure retention sediments. The device is used in conjunction with a deep-sea sediment heat preservation and pressure retention transfer storage device to complete a static penetration test under the heat preservation and pressure retention state of the deep-sea sediments. In order to achieve the above-mentioned purpose, the technical solution adopted by the present invention is as follows:

[0005] A static penetration device for deep-sea heat-insulating and pressure-maintaining sediments, comprising: a deep-sea sediment sample heat-insulating and pressure-maintaining chamber (1), a probe rod (3), a ball valve joint (4), a pressure chamber (7), a data acquisition instrument (8), a spring cable (9), a connector (11), a piston cylinder (12), a screw rod (13), a bearing (14), a sleeve (15), a nut (16), an end cover (18), a coupling (19), a motor (20), a positioning bearing unit (21), and a pressure regulating unit (25).

[0006] Preferably, the pressure chamber (7) is coaxially connected to the deep-sea sediment sample thermal insulation and pressure chamber (1) via a ball valve interface (4); the side wall of the pressure chamber (7) comprises a pressure regulating port (5) and a data acquisition interface (6); the pressure chamber (7) is filled with seawater, and the pressure regulating unit (25) increases and decreases pressure via the pressure regulating port (5) to make the pressure in the pressure chamber (7) consistent with that in the deep-sea sediment sample thermal insulation and pressure chamber (1).

[0007] Preferably, the front end of the probe rod (3) includes a conical probe (2), and the diameter of the end of the conical probe (2) is larger than the diameter of the probe rod (3); a force sensor (10) is arranged at the end of the probe rod (3), and the force sensor (10) is connected to the data acquisition instrument (8) via a spring cable (9).

[0008] Preferably, one end of the piston cylinder (12) is coaxially fixedly connected to the probe rod (3) via a connector (11); and the other end of the piston cylinder (12) is coaxially fixedly connected to a nut (16).

[0009] Preferably, the screw rod (13) and the nut (16) are threadedly connected to form a screw rod and nut mechanism; and one end of the screw rod (13) is coaxially fixedly connected to the bearing (14), and the other end of the screw rod (13) is coaxially fixedly connected to the coupling (19).

[0010] Preferably, the side wall of the nut (16) is grooved, and the pressure in the sleeve (15) is self-regulated.

[0011] Preferably, a sealing ring (17) is provided on the side wall of the end cover (18) to ensure the sealing of the device, and the end cover (18) is fixedly connected to the sleeve (15) to form a closed space.

[0012] Preferably, the motor (20) drives the screw rod (13) to rotate via the coupling (19).

[0013] Preferably, the positioning bearing unit (21) comprises a stand (22), a fixing mechanism (23), and a V-shaped block (24).

[0014] The beneficial effect of adopting the above technical solution is that during the penetration and withdrawal process of the probe rod (3), there is no fluid compression in the entire system, and the pressure remains basically constant, which not only ensures the pressure-maintaining state of the sediment, but also realizes the precise linear motion of the probe rod, accurately reflecting the relevant mechanical properties of the deep-sea sediments, which is of great strategic significance for the exploitation of deep-sea resources. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0016] Figure 1 This is a schematic diagram of the overall structure of this example;

[0017] Figure 2 This is a structural schematic diagram highlighting the positioning bearing unit in this example;

[0018] Figure 3This is a structural diagram highlighting the specific internal structure in this example.

[0019] Explanation of the reference numerals: 1-insulation and pressure-maintaining chamber for deep-sea sediment samples; 2-conical probe; 3-probe rod; 4-ball valve joint; 5-pressure regulating port; 6-data acquisition interface; 7-pressure chamber; 8-data acquisition instrument; 9-spring cable; 10-force sensor; 11-connector; 12-piston cylinder; 13-screw rod; 14-bearing; 15-sleeve; 16-nut; 17-sealing ring; 18-end cover; 19-coupling; 20-motor; 21-positioning bearing unit; 22-tripod; 23-fixing mechanism; 24-V-block; 25-pressure regulating unit. DETAILED DESCRIPTION

[0020] To make the objectives, technical solutions and advantages of the present invention more clear, the embodiments of the present invention will be further described below with reference to the accompanying drawings.

[0021] like Figures 1 to 3 As shown, a static penetration device for deep-sea heat-insulating and pressure-maintaining sediments comprises: a deep-sea sediment sample heat-insulating and pressure-maintaining chamber (1), a probe rod (3), a ball valve joint (4), a pressure chamber (7), a data acquisition instrument (8), a spring cable (9), a connector (11), a piston cylinder (12), a screw rod (13), a bearing (14), a sleeve (15), a nut (16), an end cover (18), a coupling (19), a motor (20), a positioning bearing unit (21), and a pressure regulating unit (25).

[0022] The deep-sea sediment sample insulation and pressure chamber is the main body of the static penetration test and is used to fill the sample; the pressure chamber (7) is coaxially connected to the deep-sea sediment sample insulation and pressure chamber (1) through a ball valve joint (4); the side wall of the pressure chamber (7) is provided with a pressure regulating port (5) and a data acquisition interface (6); the pressure chamber (7) is filled with seawater, and the pressure regulating unit (25) increases and decreases pressure through the pressure regulating port (5) to make the pressure of the pressure chamber (7) and the deep-sea sediment sample insulation and pressure chamber (1) consistent.

[0023] The front end of the probe rod (3) comprises a conical probe (2), the diameter of the end of the conical probe (2) is 25.2 mm, the penetration rate of the conical probe (2) can be set at a constant value between 1 and 5 mm / min, the penetration stroke is 0 to 0.5 m, the cone angle is about 60 degrees, and the diameter of the end of the conical probe (2) is greater than the diameter of the probe rod (3); a force sensor (10) is arranged at the end of the probe rod (3), and the force sensor (10) is connected to a data acquisition instrument (8) through a spring cable (9) to measure and collect the resistance of the probe rod (3) in real time.

[0024] The motor (20) is coaxially fixedly connected to the screw (13) through a coupling (19) to drive the screw to rotate; the screw (13) is threadedly connected to the inner ring of the nut (16) to form a screw-nut mechanism; one end of the piston cylinder (12) is coaxially fixedly connected to the nut (16) so that the piston cylinder moves with the nut; the other end of the piston cylinder (12) is coaxially fixedly connected to the probe rod (3) through a connector (11) to push the probe rod (3) to move.

[0025] The bearing (14) is a deep groove ball bearing, which is coaxially fixedly connected with the screw rod (13); a notch is arranged on the side wall of the nut (16), and the pressure in the sleeve (15) is self-regulated; a sealing ring (17) is arranged on the side wall of the end cover (18) to ensure the sealing performance of the device; and the end cover (18) is fixedly connected with the sleeve (15) to form a closed space.

[0026] The positioning bearing unit (21) comprises a tripod (22), a fixing mechanism (23), and a V-shaped block (24). The positioning bearing unit (21) is used to fix the sounding system, ensure that the probe rod (3) is concentric with the deep-sea sediment sample insulation and pressure chamber (1), and bear the reaction force of the sounding so that the ball valve joint (4) is not damaged by the force.

[0027] In the present invention, the whole device working steps are as follows:

[0028] (1) Close the ball valve, connect the pressure chamber and the deep-sea sediment sample insulation and pressure chamber to the two ends of the ball valve joint, ensure that the ball valve joint and the probe are concentric, and use the pressure regulating unit to pressurize the pressure chamber. When the pressure in the pressure chamber reaches the same value as the deep-sea sediment sample insulation and pressure chamber, stop pressurizing;

[0029] (2) manually opening the ball valve to connect the pressure chamber with the deep-sea sediment sample insulation and pressure chamber;

[0030] (3) Turn on the motor, and use the screw nut mechanism to penetrate and pull out the piston cylinder. The piston cylinder pushes the probe rod through the ball valve joint at a constant speed of 1-5 mm / min through the connector;

[0031] (4) The force sensor collects the penetration resistance data, which is displayed on the control panel in real time through the data acquisition instrument, and the data is recorded every 0.5 mm of penetration;

[0032] (5) After the measurement is completed, the ball valve joint is manually closed to relieve the pressure, and a graph is drawn using the penetration resistance-penetration depth as the coordinates to divide the mechanical properties of deep-sea sediments.

[0033] The above are only preferred embodiments of the present invention, and do not limit the present invention in any form. Any technician familiar with the art can make many possible changes and modifications to the technical solution of the present invention by using the above technical content without departing from the scope of the technical solution of the present invention, or modify it into an equivalent embodiment of equivalent changes. Therefore, any changes, modifications, equivalent changes and modifications made to the above embodiments based on the technology of the present invention without departing from the content of the technical solution of the present invention shall fall within the protection scope of the present technical solution.

Claims

1. A static penetration device for deep-sea heat-insulating and pressure-maintaining sediments, characterized in that: The invention comprises: a deep-sea sediment sample heat preservation and pressure preservation chamber (1), a probe rod (3), a ball valve joint (4), a pressure chamber (7), a data acquisition instrument (8), a spring cable (9), a connector (11), a piston cylinder (12), a screw rod (13), a bearing (14), a sleeve (15), a nut (16), an end cover (18), a coupling (19), a motor (20), a positioning bearing unit (21), and a pressure regulating unit (25).

2. A static penetration device for deep-sea heat-insulating and pressure-maintaining sediments according to claim 1, characterized in that: The side wall of the pressure chamber (7) comprises a pressure regulating port (5) and a data acquisition interface (6); the pressure chamber (7) is filled with seawater, and the pressure regulating unit (25) increases and decreases pressure through the pressure regulating port (5) so that the pressure in the pressure chamber (7) is consistent with the pressure in the deep-sea sediment sample heat preservation and pressure chamber (1).

3. A static penetration device for deep-sea heat-insulating and pressure-maintaining sediments according to claim 1, characterized in that: One end of the piston cylinder (12) is coaxially fixedly connected to the probe rod (3) via a connector (11); the other end of the piston cylinder (12) is coaxially fixedly connected to a nut (16).

4. A static penetration device for deep-sea heat-insulating and pressure-maintaining sediments according to claim 1, characterized in that: The screw rod (13) is coaxially fixedly connected to the motor (20) via a coupling (19); the side wall of the nut (16) is grooved; the side wall of the end cover (18) is provided with a sealing ring (17) to ensure the sealing performance of the device, and the end cover (18) is fixedly connected to the sleeve (15) to form a closed space.

5. The static penetration device for deep-sea heat-insulating and pressure-maintaining sediments according to claim 1, characterized in that: The positioning bearing unit (21) comprises a stand (22), a fixing mechanism (23), and a V-shaped block (24).

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