A device and method for measuring initial sealing force of a pressure-maintaining controller

Abstract

The present invention relates to a device and method for measuring the initial sealing force of a pressure-maintaining controller, comprising a pressure-maintaining chamber, a flap valve, and a tension-applying measuring mechanism, wherein the pressure-maintaining chamber is provided with a liquid injection channel, the flap valve is installed at the bottom of the pressure-maintaining chamber, and the tension-applying measuring mechanism is used to apply tension to the valve cover and measure the tension value. The method comprises: first, without applying tension to the valve cover, water is injected into the pressure-maintaining chamber through the liquid injection channel to pressurize the interior of the pressure-maintaining chamber, and the internal pressure of the pressure-maintaining chamber is observed through a pressure sensor; then, the tension applied to the valve cover is gradually increased through the tension-applying measuring mechanism until the flap valve stops leaking and the pressure value measured by the pressure sensor is stable. At this time, the tension value measured by the tension-applying measuring mechanism is the measured initial sealing force. The present application can measure the initial sealing force required by the flap valve, which is conducive to improving the existing pressure-maintaining controller to ensure that the flap valve can enter the initial sealing stage under the conditions of gravity and other devices providing initial sealing force, thereby ensuring that the core sample maintains the original pressure.

Description

Technical Field

[0001] The present invention relates to the technical field of pressure-maintaining controllers, and in particular to a device and method for measuring the initial sealing force of a pressure-maintaining controller. Background Art

[0002] Mineral resource development continues to move deeper into the Earth. The initial pore pressure of deep rock masses significantly influences their in-situ mechanical properties. Changes in initial pore pressure can cause changes in the rock's internal microstructure, leading to significant changes in permeability and porosity, and significant alterations in strength and deformation properties. Therefore, to develop deep resources, it is essential to obtain deep, pressure-maintained core samples and develop deep, in-situ rock mechanics theory.

[0003] The pressure controller is a core component of deep in-situ pressure coring. Its pressure-maintaining capacity and sealing performance are key to this technology. Currently, various pressure coring devices, both domestically and internationally, employ mechanical valves (ball valves or flap valves) as the pressure-maintaining sealing mechanism. For example, PCS, Hybrid PCS, PTCS, PCTB, PCB, and DAPC all utilize ball valves, while HRC, FPC, PTPS, PTPC, and MAC all utilize flap valves. Ball valves occupy a large space, limiting the diameter of the cores drilled. Flap valves offer the advantage of achieving a self-tightening seal while also allowing for larger core diameters.

[0004] For flap valves to enter the initial sealing stage, the O-ring must undergo sufficient initial compression to form a dense sealing contact surface. However, whether existing flap valves can achieve this initial sealing stage under the conditions of gravity or other devices providing initial sealing force remains unknown. Because flap valves cannot achieve an initial seal, over 30% of pressure coring samples fail to maintain pressure or only partially retain the original pressure, failing to meet the requirements of complex coring processes and conflicting with the extremely high deployment costs. Measuring the initial sealing force required for flap valves to enter the initial sealing stage is difficult. Summary of the Invention

[0005] In order to solve the above technical problems, the present application provides a device and method for measuring the initial sealing force of a pressure holding controller.

[0006] This application is implemented through the following technical solutions:

[0007] A device for measuring the initial sealing force of a pressure-maintaining controller comprises a pressure-maintaining chamber, a flap valve and a tension-applying and measuring mechanism. The pressure-maintaining chamber is provided with a liquid injection channel and is equipped with a pressure sensor. The flap valve is installed at the bottom of the pressure-maintaining chamber. The tension-applying and measuring mechanism is connected to the valve cover of the flap valve and is used to apply a downward tension to the valve cover and measure the applied tension value.

[0008] Optionally, the pressure-maintaining cabin includes a cylinder and an upper end cover, the upper end cover is threadedly connected to the upper port of the cylinder; a hole is opened on the upper end cover to form an injection channel, and the outer end of the injection channel is connected to a liquid inlet adapter; the pressure sensor is installed on the upper end cover.

[0009] Optionally, a watertight connector is installed at the inner end of the upper end cover, and a data line of the pressure sensor is connected to the watertight connector.

[0010] In particular, the pressure-maintaining cabin also includes a lower end cover, a flap valve is installed inside the lower end of the cylinder, the lower end cover is threadedly connected to the lower port of the cylinder, the upper end surface of the lower end cover is supported on the valve seat, and there is a sealing ring between the valve seat and the cylinder; there is a through hole in the center of the lower end cover.

[0011] Of course, the lower end cover can also be omitted, and the valve seat can be directly fixed coaxially with the cylinder.

[0012] Optionally, the tension application and measurement mechanism includes a force measuring device and a force applying mechanism, one end of the force measuring device is connected to the valve cover via a rigid rope, and the other end of the force measuring device is connected to the force applying mechanism.

[0013] Optionally, the force-applying mechanism includes a base, a reel mounted on the base, a rope wound around the reel, and a handle connected to the reel, and the free end of the rope is connected to one end of the force measuring device.

[0014] Preferably, the force measuring device is a spring dynamometer.

[0015] Optionally, the tension application and measurement mechanism includes a base, a pulley mounted on the base, and a weight; one end of the rigid rope is connected to the valve cover, and the other end of the rigid rope is connected to the weight after passing around the pulley.

[0016] Optionally, the tension application measurement mechanism includes an applied tension digital display device, and the applied tension digital display device is connected to the valve cover via a rigid rope.

[0017] Optionally, a small hole is opened on the lower side of the valve cover, and the rigid rope passes through the small hole to achieve connection with the valve cover.

[0018] The method for measuring the initial sealing force of a pressure-maintaining controller provided in this application adopts the aforementioned device for measuring the initial sealing force of a pressure-maintaining controller, wherein the pressure-maintaining cabin is placed horizontally, and specifically comprises the following steps:

[0019] The valve cover and valve seat are closed, and the pressure chamber is filled with water. No tension is applied to the valve cover. Water is pumped into the pressure chamber through the injection channel by the booster pump, and the pressure inside the pressure chamber is observed by the pressure sensor.

[0020] The tension applied to the valve cover is gradually increased by the tension applying and measuring mechanism until the flap valve stops leaking and the pressure value measured by the pressure sensor is stable. At this time, the tension value measured by the tension applying and measuring mechanism is the measured initial sealing force of the pressure maintaining controller.

[0021] Compared with the prior art, this application has the following beneficial effects:

[0022] This application can measure the initial sealing force required for the flap valve to enter the initial sealing stage. Based on the measured value of the initial sealing force, the existing core drill and pressure maintaining controller can be improved to ensure that the flap valve can enter the initial sealing stage under the conditions of gravity and other devices providing initial sealing force, thereby ensuring that the core sample maintains the original pressure. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The drawings described herein are used to provide a further understanding of the embodiments of the present application, constitute a part of this application, and do not constitute a limitation on the embodiments of the present invention.

[0024] Figure 1 Schematic diagram of the decoupling of the initial sealing force measuring device of the pressure holding controller in Example 1;

[0025] Figure 2 2. It is a structural diagram of the pressure-maintaining cabin and the flap valve in the embodiment;

[0026] Figure 3 is a structural diagram of the force-applying mechanism in Example 1;

[0027] Figure 4 It is a structural diagram of the force-applying mechanism in the second embodiment. DETAILED DESCRIPTION

[0028] To make the objectives, technical solutions, and advantages of this application more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings herein can be arranged and designed in a variety of different configurations.

[0029] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention as claimed, but rather merely represents selected embodiments of the present invention. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without creative effort are also within the scope of protection of the present invention.

[0030] It should be noted that, in the absence of any conflict, the embodiments and features of the embodiments of the present invention may be combined with each other. It should be noted that the various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to in conjunction with each other.

[0031] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not need to be further defined or explained in subsequent drawings.

[0032] In the description of the present invention, it should be noted that the terms "upper," "lower," "inner," and "outer" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, or the orientations or positional relationships in which the inventive product is typically placed when in use, or the orientations or positional relationships commonly understood by those skilled in the art. These terms are intended solely to facilitate the description of the present invention and to simplify the description, and are not intended to indicate or imply that the devices or components referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on the present invention. Furthermore, the terms "first," "second," and the like are used solely to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0033] In the description of the present invention, it should also be noted that, unless otherwise expressly specified or limited, the terms "disposed," "installed," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; they may refer to mechanical connections or electrical connections; they may refer to direct connections or indirect connections through an intermediate medium; and they may refer to internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances. Example 1

[0034] like Figure 1 As shown, the initial sealing force measuring device of the pressure maintaining controller disclosed in this embodiment includes a pressure maintaining chamber 1, a flap valve 2 and a tension applying and measuring mechanism.

[0035] The pressure-maintaining cabin 1 is provided with a liquid injection channel 14 , through which liquid can be injected into the pressure-maintaining cabin 1 .

[0036] The flap valve 2 is installed at the bottom of the pressure-maintaining cabin 1 to seal the lower end of the pressure-maintaining cabin 1. A pressure sensor 4 is installed on the pressure-maintaining cabin 1 to detect the pressure inside the pressure-maintaining cabin 1.

[0037] Optionally, the pressure chamber 1 includes a cylinder 11, an upper end cover 12, and a lower end cover 13. The upper end cover 12 is threadedly connected to the upper end of the cylinder 11, and the flap valve 2 is installed inside the lower end of the cylinder 11. A sealing ring is provided between the valve seat 22 and the cylinder 11. The lower end cover 13 is threadedly connected to the lower end of the cylinder 11, and the upper end surface of the lower end cover 13 abuts against the valve seat 22 of the flap valve 2 to achieve the positioning of the valve seat 22. The lower end cover 13 has a through hole in the center.

[0038] A hole is formed in the upper end cover 12 to form a liquid injection channel 14, and the outer end of the liquid injection channel 14 is connected to the liquid inlet adapter 6. The pressure sensor 4 is mounted on the upper end cover 12, and the inner end of the upper end cover 12 is equipped with a watertight connector 5. The data line of the pressure sensor 4 is connected to the watertight connector 5, which can be used to transmit data.

[0039] The tension applying and measuring mechanism is connected to the valve cover 21 of the flap valve 2 and is used to apply a downward pulling force to the valve cover 21 and measure the magnitude of the applied pulling force.

[0040] In this embodiment, the tension applying and measuring mechanism includes a force measuring device 32 and a force applying mechanism 33 . One end of the force measuring device 32 is connected to the valve cover 21 through a rigid rope 3 , and the other end of the force measuring device 32 is connected to the force applying mechanism 33 .

[0041] Optionally, a small hole 23 is opened on the lower side of the valve cover 21, both ends of the small hole 23 pass through the lower surface of the valve cover 21, one end of the rigid rope 3 passes through the small hole 23, and the other end of the rigid rope 3 is connected to one end of the force measuring device 32.

[0042] Optionally, the force measuring device 32 is a spring dynamometer.

[0043] Optionally, the pressure sensor 4 is a pressure gauge.

[0044] In this embodiment, the force-applying mechanism 33 includes a base 331 , a reel 332 mounted on the base 331 , a rope 334 wound around the reel 332 , and a handle 333 connected to the reel 332 . The free end of the rope 334 is connected to one end of the force measuring device 32 .

[0045] The method for measuring the initial sealing force of the pressure holding controller in this embodiment includes the following steps:

[0046] First, if Figure 1 As shown, the pressure-maintaining cabin 1 is placed horizontally, the valve cover 21 and the valve seat 22 are closed, the upper end cover 12 of the pressure-maintaining cabin is unscrewed, the interior of the pressure-maintaining cabin 1 is filled with water, no tension is applied to the valve cover 21, the pressure-maintaining cabin 1 is pressurized to 1 MPa, and water is pumped into the pressure-maintaining cabin 1 by the booster pump through the liquid inlet adapter 6. Since the valve cover 21 does not apply tension at this time, the flap valve 2 is not completely sealed, and therefore the pressure value measured by the pressure sensor 4 is always 0 at this time;

[0047] Then, shake the handle 333 and gradually increase the pulling force on the valve cover 21 through the force-applying mechanism 33 until the flap valve 2 stops leaking. This indicates that the valve cover 21 has achieved initial sealing, the internal pressure of the pressure-maintaining cabin 1 is stable, and the pressure value measured by the pressure sensor 4 is also stable. At this time, the measurement value of the force measuring device 32 is the measured initial sealing force. Example 2

[0048] The tension applying and measuring mechanism of this embodiment is different from that of the first embodiment, specifically: Figure 4 As shown, the tension application and measurement mechanism includes a base 331 , a pulley 335 mounted on the base 331 , and a weight 336 . One end of the rigid rope 3 is connected to the valve cover 21 , and the other end of the rigid rope 3 is connected to the weight 336 after passing through the pulley 335 .

[0049] The method for measuring the initial sealing force of the pressure holding controller in this embodiment includes the following steps:

[0050] First, the valve cover 21 and the valve seat 22 are closed, the upper end cover 12 of the pressure chamber is unscrewed, and the interior of the pressure chamber 1 is filled with water. No tension is applied to the valve cover 21, that is, the other end of the rigid rope 3 is not connected to the weight 336; the pressure chamber 1 is pressurized to 1 MPa, and water is pumped into the pressure chamber 1 by the booster pump through the liquid inlet adapter 6. It can be observed through the pressure sensor 4 that the pressure reading is always 0

[0051] Then, the other end of the rigid rope 3 is connected to the weight 336, and the number or weight of the weight is continuously increased. The pulling force on the valve cover 21 is gradually increased through the force-applying mechanism 33 until the flap valve 2 stops leaking and the pressure reading measured by the pressure sensor 4 is stable. At this time, the gravity value corresponding to the weight 336 is the measured initial sealing force. Example 3

[0052] The tension application and measurement mechanism of this embodiment is different from that of the first embodiment. The tension application and measurement mechanism of this embodiment is a tension application digital display device.

[0053] The method for measuring the initial sealing force of the pressure holding controller in this embodiment includes the following steps:

[0054] First, close the valve cover 21 and the valve seat 22, unscrew the upper end cover 12 of the pressure chamber, fill the pressure chamber 1 with water, do not apply tension to the valve cover 21, pressurize the pressure chamber 1 to 1 MPa, and pump water into the pressure chamber 1 through the liquid inlet adapter 6 by the booster pump. The pressure reading on the pressure sensor 4 is always 0.

[0055] Then, the pulling force on the valve cover 21 is gradually increased by the force applying mechanism 33 until the flap valve 2 stops leaking and the pressure reading measured by the pressure sensor 4 is stable. At this time, the force value applied by the tension digital display device is the measured initial sealing force.

[0056] It is worth noting that the digital display device for applying tension includes a force-applying mechanism, a tension sensor and a control system. The force-applying mechanism is connected to the valve cover 21 through the tension sensor, and the tension sensor is connected to the control system. The control system includes a control unit, a display unit, etc. The tension curve can be output in real time through the display unit. This is a conventional technology in this field and will not be repeated here.

[0057] This application can measure the initial sealing force required for the flap valve to enter the initial sealing stage. Based on the measured value of the initial sealing force, the existing core drill and pressure maintaining controller can be improved to ensure that the flap valve can enter the initial sealing stage under the conditions of gravity and other devices providing initial sealing force, thereby ensuring that the core sample maintains the original pressure.

[0058] The above specific implementation methods further illustrate the purpose, technical solutions and beneficial effects of this application in detail. It should be understood that the above are only specific implementation methods of the present invention and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for measuring the initial sealing force of a pressure holding controller, characterized in that: The initial sealing force measuring device of the pressure holding controller is used. The initial sealing force measuring device of the pressure holding controller includes: A pressure-maintaining cabin (1) is provided with a liquid injection channel (14), and a pressure sensor (4) is installed on the pressure-maintaining cabin (1); A flap valve (2) is installed at the bottom of the pressure-maintaining cabin (1); A tension applying and measuring mechanism is connected to the valve cover (21) of the flap valve (2) and is used to apply a downward tension to the valve cover (21) and measure the applied tension value; The following steps are involved: The pressure-maintaining cabin (1) is placed horizontally, the valve cover (21) and the valve seat (22) are closed, the interior of the pressure-maintaining cabin (1) is filled with water, no tension is applied to the valve cover (21), water is pumped into the interior of the pressure-maintaining cabin (1) through the injection channel (14) by the booster pump, and the internal pressure of the pressure-maintaining cabin (1) is observed through the pressure sensor (4); The tension applied to the valve cover (21) is gradually increased by the tension applying and measuring mechanism until the flap valve (2) stops leaking and the pressure value measured by the pressure sensor (4) is stable. At this time, the tension value measured by the tension applying and measuring mechanism is the measured initial sealing force of the pressure maintaining controller.

2. The method for measuring the initial sealing force of a pressure-maintaining controller according to claim 1, wherein: The pressure-maintaining cabin (1) comprises a cylinder (11) and an upper end cover (12), wherein the upper end cover (12) is threadedly connected to the upper end of the cylinder (11); A hole is opened on the upper end cover (12) to form a liquid injection channel (14), and the outer end of the liquid injection channel (14) is connected to a liquid inlet adapter (6); and a pressure sensor (4) is mounted on the upper end cover (12).

3. The method for measuring the initial sealing force of a pressure-maintaining controller according to claim 2, wherein: The inner end of the upper end cover (12) is provided with a watertight connector (5), and the data line of the pressure sensor (4) is connected to the watertight connector (5).

4. A method for measuring the initial sealing force of a pressure-maintaining controller according to claim 2 or 3, characterized in that: The pressure-maintaining cabin (1) further comprises a lower end cover (13), a flap valve (2) is installed inside the lower end of the cylinder (11), the lower end cover (13) is threadedly connected to the lower end port of the cylinder (11), the upper end surface of the lower end cover (13) is abutted against the valve seat (22), and a sealing ring is provided between the valve seat (22) and the cylinder (11); and a through hole is provided in the center of the lower end cover (13).

5. The method for measuring the initial sealing force of a pressure-maintaining controller according to claim 1, wherein: The tension applying and measuring mechanism comprises a force measuring device (32) and a force applying mechanism (33), wherein one end of the force measuring device (32) is connected to the valve cover (21) via a rigid rope (3), and the other end of the force measuring device (32) is connected to the force applying mechanism (33).

6. The method for measuring the initial sealing force of a pressure-maintaining controller according to claim 5, characterized in that: The force applying mechanism (33) comprises a base (331), a reel (332) mounted on the base (331), a rope (334) wound around the reel (332), and a handle (333) connected to the reel (332); a free end of the rope (334) is connected to one end of the force measuring device (32).

7. A method for measuring the initial sealing force of a pressure-maintaining controller according to claim 5 or 6, characterized in that: The force measuring device (32) is a spring dynamometer.

8. The method for measuring the initial sealing force of a pressure-maintaining controller according to claim 1, characterized in that: The tension applying and measuring mechanism comprises a base (331), a pulley (335) mounted on the base (331), and a weight (336); one end of the rigid rope (3) is connected to the valve cover (21); the other end of the rigid rope (3) passes around the pulley (335) and is connected to the weight (336); Alternatively, the tension application measuring mechanism includes a tension application digital display device, and the tension application digital display device is connected to the valve cover (21) via a rigid rope (3).

9. A method for measuring the initial sealing force of a pressure-maintaining controller according to claim 5, 6 or 8, characterized in that: A small hole (23) is formed on the lower side of the valve cover (21), and the rigid rope (3) passes through the small hole (23) to achieve connection with the valve cover (21).

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