Closed liquid discharging device of closed rock core taking tool

Abstract

The utility model discloses a closed liquid discharging device of a closed core taking tool, and belongs to the technical field of well drilling and core taking. A closed liquid discharging device of a closed core taking tool comprises an outer cylinder, an inner cylinder, a drill bit and a plug, a storage cavity is formed in the outer cylinder, a sealing plug is arranged in the storage cavity in a sliding mode, the inner cylinder is arranged in the storage cavity, the outer cylinder is in clearance fit with the inner cylinder, the drill bit is fixedly installed at the bottom end of the inner cylinder, and the plug is inserted in the middle of the drill bit in a sliding mode and protrudes out of the drill bit outwards. A pressure container is arranged in the outer cylinder, a control valve is installed on the pressure container, a balance cavity is formed in the outer cylinder, the pressure container is used for injecting pressurizing media into the balance cavity, and the balance cavity is communicated with the storage cavity. The control valve is arranged to control the pressurization medium in the pressure container to be discharged outwards and is used for controlling the discharging speed of the rock core sealing liquid in the storage cavity, so that the speed of the rock core sealing liquid is not limited by the tunneling speed of the drill bit.

Description

Technical Field

[0001] The present application relates to the technical field of drilling coring, and more specifically, to a closed fluid discharge device for a closed coring tool. Background Art

[0002] In order to avoid the core being contaminated by drilling fluid during the coring drilling process, it is necessary to fill the coring tool with sealing fluid. During coring drilling, the sealing fluid is squeezed out to form a protective film wrapped around the outer surface of the core, thereby preventing the drilling fluid from directly flushing the core and maintaining the core in its original state.

[0003] After searching, the patent document with the existing announcement number CN207554001U provides a closed coring tool, which is provided with a sealing device in the inner tube, and a first sealing ring is provided on the sealing device, and the first sealing ring is connected to the inner wall of the core claw assembly. During the coring operation, the core sealing liquid in the inner tube is squeezed out by the core and wraps the core. The wrapping of the core sealing liquid can prevent the core from being contaminated by the drilling fluid, and play a role in protecting the core. The wrapping of the core sealing liquid isolates the core from the drilling fluid.

[0004] Although the above device can use the sealing device to squeeze the sealing liquid to wrap the rock side wall, it cannot effectively control the extrusion speed of the sealing liquid and it is difficult to ensure that the sealing liquid can evenly cover the core. In view of this, we propose a sealing liquid discharge device for a closed core sampling tool. Utility Model Content

[0005] 1. Technical issues to be solved

[0006] The purpose of the present application is to provide a closed fluid discharge device for a closed core sampling tool to solve the problems raised in the above-mentioned background technology.

[0007] 2. Technical solution

[0008] This application is implemented through the following technical solutions:

[0009] A closed liquid discharge device for a closed core sampling tool comprises an outer cylinder, an inner cylinder, a drill bit and a plug. A storage cavity is opened in the outer cylinder, a sealing plug is slidably provided in the storage cavity, the inner cylinder is arranged in the storage cavity, the outer cylinder and the inner cylinder are clearance-matched, the drill bit is fixedly mounted at the bottom end of the inner cylinder, the plug is slidably inserted in the middle of the drill bit and protrudes the drill bit outward, a pressure vessel is arranged in the outer cylinder, a control valve is installed on the pressure vessel, a balancing cavity is arranged in the outer cylinder, the pressure vessel is used to inject pressurized medium into the balancing cavity, and the balancing cavity is connected to the storage cavity.

[0010] As an optional solution to the technical solution of the present application document, the upper diameter of the plug is larger than the lower diameter, the upper diameter of the inner tube is larger than the lower diameter, the plug is slidably matched with the inner tube, and a through hole is opened at the diameter change portion of the inner tube.

[0011] As an optional solution of the technical solution of this application document, the plug is connected to the inner tube through a shear pin.

[0012] As an optional solution of the technical solution of this application document, a pressure reduction chamber is opened in the outer cylinder, the pressure reduction chamber is located above the balancing chamber and is connected to the balancing chamber, and a one-way pressure valve is installed between the pressure reduction chamber and the balancing chamber.

[0013] As an optional solution of the technical solution of this application document, a pressure relief valve is also installed between the pressure reduction chamber and the balance chamber.

[0014] As an optional solution to the technical solution of the present application document, the inner wall of the inner tube is fixed with multiple inward protrusions, the top of the protrusions is flush with the inner wall surface of the lower part of the inner tube, and the upper part of the plug is provided with multiple slide grooves, and the bottom of the slide grooves is flush with the outer wall of the lower part of the plug.

[0015] As an optional solution to the technical solution of the present application document, the outer cylinder includes an upper cylinder and a lower cylinder, the upper cylinder is threadedly connected to the lower cylinder, the inner cylinder is threadedly connected to the lower cylinder, the balance chamber is located between the upper cylinder and the lower cylinder, and the storage chamber is located in the lower cylinder.

[0016] 3. Beneficial effects

[0017] Compared with the prior art, the beneficial effects of this application are:

[0018] The present application sets a control valve to control the discharge of the pressurized medium in the pressure vessel to the outside, which is used to control the discharge speed of the core sealing fluid in the storage chamber, so that the speed of the core sealing fluid will not be limited by the drilling speed of the drill bit, and can always maintain a stable speed to discharge outward, wrap the core, and avoid the core being contaminated by the drilling fluid. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of the overall structure of a closed fluid discharge device for a closed core sampling tool;

[0020] Figure 2 It is an enlarged schematic diagram of the structure at point A of a closed fluid discharge device for a closed core sampling tool;

[0021] In the figure: 1. outer cylinder; 101. storage chamber; 102. sealing plug; 103. balance chamber; 104. pressure reducing chamber; 105. upper cylinder; 106. lower cylinder; 2. inner cylinder; 201. through hole; 202. protrusion; 3. drill bit; 4. plug; 401. slide groove; 5. pressure vessel; 6. control valve; 7. shear pin; 8. one-way pressure valve; 9. pressure relief valve. DETAILED DESCRIPTION

[0022] The technical solution of the present application will be described clearly and completely below in conjunction with the accompanying drawings.

[0023] See also Figure 1 The present application provides a closed fluid discharge device for a closed core sampling tool, comprising an outer tube 1, an inner tube 2, a drill bit 3, and a plug 4.

[0024] The outer cylinder 1 includes an upper cylinder 105 and a lower cylinder 106, the upper cylinder 105 is threadedly connected with the lower cylinder 106, a storage chamber 101 is provided in the lower cylinder 106, a sealing plug 102 is slidably provided in the storage chamber 101, the inner cylinder 2 is arranged in the storage chamber 101, the lower cylinder 106 and the inner cylinder 2 are clearance-matched, the inner cylinder 2 and the lower cylinder 106 are threadedly connected, and the drill bit 3 is fixedly installed at the bottom end of the inner cylinder 2. By removing the inner cylinder 2 from the lower cylinder 106, injecting the core sealing liquid into the storage chamber 101, and then installing the inner cylinder 2 at the end of the lower cylinder 106, the sealing plug 102 can be used to prevent the core sealing liquid from overflowing upward.

[0025] like Figure 2 As shown, the plug 4 is slidably inserted in the middle of the drill bit 3 and protrudes outward from the drill bit 3. The upper diameter of the plug 4 is larger than the lower diameter, and the upper diameter of the inner tube 2 is larger than the lower diameter. The plug 4 and the inner tube 2 are slidably matched. A through hole 201 is opened at the diameter change portion of the inner tube 2. The plug 4 and the inner tube 2 are connected by a shear pin 7.

[0026] When the device is sent into the well, the plug 4 will first come into contact with the rock. By driving the device to move downward, the shear pin 7 between the plug 4 and the inner tube 2 will be destroyed, so that the plug 4 can move upward, and the core sealing fluid in the storage chamber 101 can enter the through hole 201 through the gap between the outer tube 1 and the inner tube 2, and enter between the inner tube 2 and the plug 4 through the through hole 201, and overflow to the outside; in the process of the drill bit 3 drilling downward, the overflowed core sealing fluid can be wrapped around the outside of the core to prevent the core from being contaminated by the drilling fluid.

[0027] A pressure vessel 5 is provided in the upper cylinder 105, and a control valve 6 is installed on the pressure vessel 5. A balance chamber 103 is provided between the upper cylinder 105 and the lower cylinder 106. The pressure vessel 5 is used to inject a pressurized medium into the balance chamber 103. The pressurized medium may be compressed air. The balance chamber 103 is connected to the storage chamber 101. The pressurized medium in the pressure vessel 5 may be injected into the balance chamber 103 by setting the opening time of the control valve 6, or when the shear pin 7 is damaged, the control valve 6 may be controlled to open, and a downward force may be applied to the sealing plug 102. The sealing plug 102 is used to push the core sealing liquid in the storage chamber 101 downward to overflow, thereby controlling the discharge speed of the core sealing liquid, so that the core sealing liquid can be evenly wrapped around the outside of the core.

[0028] A decompression chamber 104 is provided in the outer cylinder 1. The decompression chamber 104 is located above the balancing chamber 103 and is connected to the balancing chamber 103. A one-way pressure valve 8 is installed between the decompression chamber 104 and the balancing chamber 103, and a pressure relief valve 9 is also installed between the decompression chamber 104 and the balancing chamber 103. During the downward excavation of the drill bit 3, the core will enter the inner cylinder 2 by pushing the plug 4, displacing the core sealing liquid in the storage chamber 101, resulting in excessive pressure inside the core sealing liquid. The pressurized medium discharged into the balancing chamber 103 will enter the decompression chamber 104 through the one-way pressure valve 8, avoiding excessive pressure inside the core sealing liquid, increasing the discharge speed of the core sealing liquid, and increasing the consumption of the core sealing liquid. After the core collection is completed, the pressurized medium in the balancing chamber 103 is discharged by separating the upper cylinder 105 and the lower cylinder 106, and then the pressurized medium in the decompression chamber 104 is discharged through the pressure relief valve 9.

[0029] The inner wall of the inner cylinder 2 is fixed with a plurality of inward protrusions 202, the top of the protrusions 202 is flush with the inner wall surface of the lower part of the inner cylinder 2, and the upper part of the plug 4 is provided with a plurality of chute 401, the bottom of the chute 401 is flush with the outer wall of the lower part of the plug 4. After the core enters the inner cylinder 2, it can be confined between the protrusions 202, preventing the core from breaking under external action and maintaining the integrity of the core.

Claims

1. A closed fluid discharge device for a closed core sampling tool, comprising an outer cylinder (1), an inner cylinder (2), a drill bit (3), and a plug (4), characterized in that: The outer cylinder (1) is provided with a storage chamber (101), a sealing plug (102) is slidably provided in the storage chamber (101), the inner cylinder (2) is arranged in the storage chamber (101), the outer cylinder (1) and the inner cylinder (2) are clearance-matched, the drill bit (3) is fixedly mounted at the bottom end of the inner cylinder (2), the plug (4) is slidably inserted in the middle of the drill bit (3) and protrudes outward from the drill bit (3), the outer cylinder (1) is provided with a pressure container (5), a control valve (6) is installed on the pressure container (5), the outer cylinder (1) is provided with a balancing chamber (103), the pressure container (5) is used to inject a pressurized medium into the balancing chamber (103), and the balancing chamber (103) is in communication with the storage chamber (101).

2. The device for discharging sealed fluid from a sealed core sampling tool according to claim 1, characterized in that: The upper diameter of the plug (4) is greater than the lower diameter, the upper diameter of the inner tube (2) is greater than the lower diameter, the plug (4) and the inner tube (2) are slidably matched, and a through hole (201) is provided at the diameter change portion of the inner tube (2).

3. The device for discharging sealed fluid from a sealed core sampling tool according to claim 1, characterized in that: The plug (4) and the inner tube (2) are connected via a shear pin (7).

4. The enclosed fluid discharge device for enclosed coring tool according to claim 1, characterized in that: A pressure reducing chamber (104) is provided in the outer cylinder (1); the pressure reducing chamber (104) is located above the balancing chamber (103) and is in communication with the balancing chamber (103); a one-way pressure valve (8) is installed between the pressure reducing chamber (104) and the balancing chamber (103).

5. The device for discharging sealed fluid from a sealed core sampling tool according to claim 4, characterized in that: A pressure relief valve (9) is also installed between the pressure reduction chamber (104) and the balance chamber (103).

6. The device for discharging sealed fluid from a sealed core sampling tool according to claim 2, characterized in that: The inner wall of the inner cylinder (2) is fixed with a plurality of inward protrusions (202), the tops of the protrusions (202) are flush with the surface of the lower inner wall of the inner cylinder (2), the upper part of the plug (4) is provided with a plurality of slide grooves (401), the bottoms of the slide grooves (401) are flush with the lower outer wall of the plug (4).

7. The device for discharging sealed fluid from a sealed core sampling tool according to claim 1, characterized in that: The outer cylinder (1) comprises an upper cylinder (105) and a lower cylinder (106); the upper cylinder (105) is threadedly connected to the lower cylinder (106); the inner cylinder (2) is threadedly connected to the lower cylinder (106); the balancing chamber (103) is located between the upper cylinder (105) and the lower cylinder (106); and the storage chamber (101) is located inside the lower cylinder (106).

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