A kind of underground safety production device

Abstract

The present invention discloses a downhole safety production device, including: a safety valve, a docking device and a control pipeline; the safety valve includes: a shell, a piston assembly and a valve plate both installed in the shell; a hydraulic chamber is formed between the upper end of the piston assembly and the shell, and the lower end of the piston assembly cooperates with the valve plate; a channel connected to the hydraulic chamber is arranged on the shell, and a docking hole connected to the channel is also arranged in the shell; the control pipeline is located in the pipe column, one end of the control pipeline is connected to the control device arranged at the wellhead, and the other end of the control pipeline is connected to the docking device; the docking device is sealed and docked in the docking hole. Accordingly, the control pipeline connected to the docking device is arranged inside the pipe column, and there is no need to install a clip for fixing the control pipeline on the outer wall of the pipe column. When the well is inspected and repaired, the docking device is removed from the safety valve through the control pipeline, so that the operation of lifting the pipe column for blowout prevention can be carried out very conveniently, and at the same time, the pipe lifting speed of the blowout prevention operation can be greatly improved, avoiding safety hazards.

Description

Technical Field

[0001] The invention relates to the technical field of oil and gas production tools in oil fields, in particular to an underground safe production device. Background Art

[0002] Downhole safety valve is installed in oil and gas wells. In the event of fire, pipeline rupture, or irresistible natural disasters (such as earthquakes, ice conditions, strong typhoons, etc.), it can close the downhole production channel in time to prevent oil and gas leakage from causing environmental pollution and other safety accidents. The control pipeline of the downhole safety valve is connected to its hydraulic cavity through a docking device, and hydraulic oil is added to the hydraulic cavity from the ground. Figure 1 As shown, high-pressure liquid enters the hydraulic chamber e through the control pipeline a, pushing the piston b downward, compressing the spring c, and the piston b pushes the valve plate d to open the downhole safety valve; maintaining the ground control pressure, the downhole safety valve remains in the open state; releasing the ground control pressure, the valve plate d is reset under the action of the torsion spring at its rotating shaft, and the downhole safety valve is closed.

[0003] like Figure 1 As shown, currently the downhole safety valve control pipeline a is connected to the outside of the oil pipe and to the outer pipe wall of the downhole safety valve. During the high-pressure well repair process, the control pipeline is also clamped on the outer wall of the oil pipe by the pipeline clamp. During the high-pressure oil, gas and water well repair process, the installation position of the control pipeline a will bring huge workload and construction risks to the pipe string for blowout prevention operations. Summary of the invention

[0004] In view of the problems existing in the prior art, the purpose of the present invention is to provide an underground production safety device, which can well solve the technical problem of lifting the pipe string in blowout prevention operations.

[0005] To achieve the above object, the technical solution of the present invention is as follows:

[0006] An underground production safety device, comprising: a safety valve, a docking device and a control pipeline;

[0007] The safety valve comprises: a housing, a piston assembly and a valve plate both mounted in the housing; a hydraulic cavity is formed between the upper end of the piston assembly and the housing, and the lower end of the piston assembly cooperates with the valve plate; a liquid flow channel communicating with the hydraulic cavity is provided on the housing, and a docking hole communicating with the liquid flow channel is also provided in the housing;

[0008] The control pipeline is located in the pipe string, one end of the control pipeline is connected to a control device arranged at the wellhead, and the other end of the control pipeline is connected to the docking device; the docking device is sealed and docked in the docking hole.

[0009] Furthermore, a sliding sleeve is installed in the docking hole of the safety valve, the outer wall of the sliding sleeve is fitted with the inner wall of the docking hole, and shear pins for limiting the sliding sleeve are installed in the docking hole so that the sliding sleeve closes the liquid flow channel.

[0010] Furthermore, an inner boss is arranged in the outer shell above the hydraulic chamber, the docking hole passes through the inner boss, the docking hole includes a first hole section located at the upper part and a second hole section located at the lower part, the inner diameter of the first hole section is smaller than the inner diameter of the second hole section, the second hole section is connected with the liquid flow channel, and the sliding sleeve is installed in the second hole section and fits with the inner wall of the second hole section.

[0011] Furthermore, first sealing grooves are provided on both upper and lower sides of the inner wall of the second hole section connected to the liquid flow channel. The first sealing groove is located at the matching position of the second hole section and the sliding sleeve, and a first sealing ring is installed in the first sealing groove.

[0012] Further, the docking device includes: a main body matched with the first hole section, a sealing sleeve mounted on the lower part of the main body, a retaining ring, a sealing ring, a limiting sleeve, a first limiting shear pin and a second limiting shear pin; the outer diameter of the sealing sleeve matches the second hole section; the sealing sleeve is provided with a radial first positioning hole, and the first limiting shear pin passes through the first positioning hole to fix the sealing sleeve to the main body; the outer wall of the main body is provided with a retaining ring groove and a sealing ring groove, the distance between the upper end surface of the sealing sleeve and the retaining ring groove is greater than the sum of the axial lengths of the first hole section and the sliding sleeve, the sealing ring groove is provided between the retaining ring groove and the sealing sleeve, the distance between the retaining ring groove and the sealing ring groove is less than the axial length of the first hole section, and the retaining ring and the sealing ring are respectively installed in the retaining ring groove and the sealing ring groove.

[0013] Furthermore, the docking device also includes an annular limit sleeve and a second limit shear pin, the outer diameter of the limit sleeve is larger than the inner diameter of the second hole section, the limit sleeve is provided with a radial second positioning hole, the second limit shear pin passes through the second positioning hole to fix the limit sleeve to the lower end of the main body, and the distance from the upper end surface of the limit sleeve to the retaining ring groove is greater than or equal to the thickness of the inner boss.

[0014] Furthermore, an axial liquid flow channel and a radial liquid flow channel communicating with the axial liquid flow channel are arranged in the main body of the docking device, the axial liquid flow channel passes through the upper end surface of the main body, and the radial liquid flow channel radially passes through the main body; the inner wall of the lower part of the sealing sleeve is in contact with the outer wall of the main body, and there is a gap between the upper part of the sealing sleeve and the outer wall of the main body, and radial guide holes are also arranged on the upper part of the sealing sleeve; when the docking device is sealed and installed in the docking hole, the radial liquid flow channel is located on the upper part of the sealing sleeve, and the guide hole corresponds to the liquid flow channel.

[0015] Furthermore, a second sealing groove is provided on the inner wall and the outer wall of the lower part of the sealing sleeve, and a second sealing ring is installed in the second sealing groove.

[0016] Furthermore, a fluid infusion channel connected to the hydraulic chamber is provided on the shell of the safety valve, the fluid infusion channel is connected to the end surface of the shell, and a sealing member is installed in the fluid infusion channel from the end surface side of the shell.

[0017] Furthermore, the shear force of the first position-limiting shear nail is smaller than the shear force of the second position-limiting shear nail.

[0018] The underground production safety device of the present invention seals the docking hole connected to the hydraulic chamber of the safety valve through the docking device. When a safety accident occurs, the docking device is disengaged from the docking hole to relieve the pressure of the hydraulic chamber so that the safety valve can be automatically closed. Accordingly, the control pipeline connected to the docking device is arranged inside the pipe string, and there is no need to install a clip for fixing the control pipeline on the outer wall of the pipe string. When the well is inspected and repaired, the docking device is removed from the safety valve through the control pipeline, so that the operation of lifting the pipe string for blowout prevention can be carried out very conveniently, and at the same time, the lifting speed of the pipe for blowout prevention operation can be greatly improved, avoiding safety hazards. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a structural schematic diagram of the connection between the hydraulic control pipeline and the downhole safety valve in the background technology;

[0020] Figure 2 This is a schematic diagram of the docking installation of the docking device and the safety valve in Example 1 of the present invention;

[0021] Figure 3 A schematic diagram of the structure of the docking device provided in Example 1 of the present invention;

[0022] Figure 4 It is a schematic structural diagram of the sealing state of the docking device and the safety valve in the embodiment 1 of the present invention;

[0023] Figure 5 for Figure 4 Schematic diagram of hydraulic oil flow in the state;

[0024] Figure 6 This is a schematic diagram of the butt joint and the safety valve being disconnected in Embodiment 1 of the present invention;

[0025] Figure 7 This is a schematic diagram of the salvage and docking installation process of the control pipeline and the safety valve in Example 1 of the present invention;

[0026] Figure 8 This is a schematic diagram of the docking installation of the docking device and the safety valve in Example 2 of the present invention;

[0027] Fig. 9 A schematic diagram of the structure of a docking device provided in Example 2 of the present invention;

[0028] Fig.10 It is a structural schematic diagram of the sealing state of the docking device and the safety valve in the second embodiment of the present invention;

[0029] Fig.11 This is a schematic diagram of the butt joint and the safety valve being disconnected in Embodiment 2 of the present invention;

[0030] Fig.12 A schematic diagram of the structure of a safety valve provided in Example 3 of the present invention;

[0031] In the figure:

[0032] 1. docking device; 11. main body; 111. axial channel; 112. radial channel; 12. retaining ring; 13. sealing ring; 14. sealing sleeve; 141. guide hole; 142. second sealing ring; 15. first limit shear nail; 16. limit sleeve; 17. second limit shear nail; 18. thread; 2. safety valve; 21. docking hole; 211. first hole section; 212. second hole section; 22. sliding sleeve; 23. shear nail; 24. liquid flow channel; 25. first sealing ring; 26. infusion channel; 27. sealing element; 28. inner boss; 3. hydraulic chamber; 4. control pipeline joint; 5. control pipeline; 6. oil pipe; 7. salvage device; 71. salvage head; 72. centralizer. DETAILED DESCRIPTION

[0033] In order to clearly illustrate the design concept of the present invention, the present invention is described below in conjunction with examples.

[0034] In order to enable those skilled in the art to better understand the solution of the present invention, the technical solution of the present invention is clearly and completely described below in conjunction with the drawings in the examples of the present invention. Obviously, the described examples are only part of the examples of the present invention, not all of the examples. Based on the examples in the present invention, all other implementation methods obtained by ordinary technicians in the field without making creative work should fall within the scope of protection of the present invention.

[0035] In the description of the present embodiment, the terms "upper", "lower", "left", "right", etc., indicating directions or positional relationships are based on the directions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are only used to distinguish similar objects, and cannot be understood as a specific order or sequence, and it should be understood that such usage can be interchangeable under appropriate circumstances.

[0036] The present invention provides an underground production safety device, comprising: a safety valve, a docking device and a control pipeline;

[0037] The safety valve comprises: a housing, a piston assembly and a valve plate both mounted in the housing; a hydraulic cavity is formed between the upper end of the piston assembly and the housing, and the lower end of the piston assembly cooperates with the valve plate; a liquid flow channel connected to the hydraulic cavity is provided on the housing, and a docking hole connected to the liquid flow channel is also provided in the housing;

[0038] The control pipeline is located in the pipe string, one end of the control pipeline is connected to the control device arranged at the wellhead, and the other end of the control pipeline is connected to the docking device; the docking device is sealed and docked in the docking hole.

[0039] The underground production safety device of the present invention seals the docking hole connected to the hydraulic chamber of the safety valve through the docking device. When a safety accident occurs, the docking device is disengaged from the docking hole to relieve the pressure of the hydraulic chamber so that the safety valve can be automatically closed. Accordingly, the control pipeline connected to the docking device is arranged inside the pipe string, and there is no need to install a clip for fixing the control pipeline on the outer wall of the pipe string. When the well is inspected and repaired, the docking device is removed from the safety valve through the control pipeline, so that the operation of lifting the pipe string for blowout prevention can be carried out very conveniently, and at the same time, the lifting speed of the pipe for blowout prevention operation can be greatly improved, avoiding safety hazards.

[0040] In order to more clearly explain the technical solution in the present invention, the present invention will be described in detail below with reference to the accompanying drawings and in combination with embodiments. In the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other.

[0041] Example 1

[0042] like Figure 2-6 As shown, a first embodiment of the underground production safety device of the present invention is provided, comprising: a safety valve 2, a docking device 1 and a control pipeline 5;

[0043] The safety valve 2 comprises: a housing, a piston assembly and a valve plate both mounted in the housing; a hydraulic chamber 3 is formed between the upper end of the piston assembly and the housing, and the lower end of the piston assembly cooperates with the valve plate; a liquid flow channel 24 communicating with the hydraulic chamber is provided on the housing, and a docking hole 21 communicating with the liquid flow channel 24 is also provided in the housing;

[0044] The control pipeline 5 is located in the pipe string, one end of the control pipeline 5 is connected to a control device arranged at the wellhead, and the other end of the control pipeline is connected to the docking device 1; the docking device 1 is sealed and docked in the docking hole 21.

[0045] A sleeve 22 is also installed in the docking hole 21 of the safety valve 2, and the outer wall of the sleeve 22 fits the inner wall of the docking hole 21. A shear pin 23 for limiting the sleeve 22 is also installed in the docking hole 21, so that the sleeve 22 closes the liquid flow channel 24. When the docking device 1 is not docked with the safety valve 2, the safety valve 2 can also ensure a closed state.

[0046] An inner boss 28 is arranged in the outer shell above the hydraulic chamber 3, and the docking hole 21 passes through the inner boss 28. The docking hole 21 includes a first hole section 211 located at the upper part and a second hole section 212 located at the lower part. The inner diameter of the first hole section 211 is smaller than the inner diameter of the second hole section 212. The second hole section 212 is connected to the liquid flow channel 24. The sliding sleeve 22 is installed in the second hole section 212 and fits with the inner wall of the second hole section 212.

[0047] The first sealing grooves are arranged on both the upper and lower sides of the inner wall of the second hole section 212 communicating with the liquid flow channel 24. The first sealing grooves are located at the matching position of the second hole section 212 and the sliding sleeve 22. The first sealing ring 25 is installed in the first sealing grooves to ensure good sealing of the safety valve 2 when the docking device 1 and the safety valve 2 are not docked.

[0048] The docking device 1 comprises: a main body 11 matched with the first hole section 211, a sealing sleeve 14 fitted to the lower part of the main body 11, a snap ring 12, a sealing ring 13, a limiting sleeve 16, a first limiting shear nail 15 and a second limiting shear nail 17; the outer diameter of the sealing sleeve 14 matches the second hole section 212; the sealing sleeve 14 is provided with a radial first positioning hole, and the first limiting shear nail 15 passes through the first positioning hole to fix the sealing sleeve 14 to the main body 11; the outer wall of the main body 11 is provided with a snap ring groove and a sealing ring groove, and the snap ring groove and the sealing ring groove are provided. A retaining ring 12 and a sealing ring 13 are respectively installed in the ring groove. The distance between the upper end surface of the sealing sleeve 14 and the retaining ring groove is greater than the sum of the axial lengths of the first hole section 211 and the sliding sleeve 22, ensuring that after the docking device 1 and the docking hole 21 are sealed, the retaining ring groove exposes the upper part of the docking hole 21, and the retaining ring 12 is removed from the retaining ring groove. The sealing ring groove is arranged between the retaining ring groove and the sealing sleeve 14, and the distance between the retaining ring groove and the sealing ring groove is less than the axial length of the first hole section 211, ensuring the cooperation of the sealing ring 13 with the first hole section 211.

[0049] The docking device also includes an annular limiting sleeve 16 and a second limiting shear nail 17. The outer diameter of the limiting sleeve 16 is greater than the inner diameter of the second hole section 212. The limiting sleeve 16 is provided with a radial second positioning hole. The second limiting shear nail 17 passes through the second positioning hole to fix the limiting sleeve 16 to the lower end of the main body 11. The distance from the upper end surface of the limiting sleeve 16 to the snap ring groove is greater than or equal to the thickness of the inner boss 28. When the docking device 1 is sealed and docked with the safety valve 2, it is ensured that the snap ring groove is located above the docking hole 21 and the limiting sleeve 16 is located below the docking hole.

[0050] In particular, an axial channel 111 and a radial channel 112 communicating with the axial channel 111 are provided in the main body 11; the axial channel 111 passes through the upper end surface of the main body 11, and the radial channel 112 radially passes through the main body 11; the inner wall of the lower part of the sealing sleeve 14 fits with the outer wall of the main body 11, and there is a gap between the upper part of the sealing sleeve 14 and the outer wall of the main body 11, and a radial guide hole 141 is also provided on the upper part of the sealing sleeve 14; when the docking device 1 is sealed and installed in the docking hole 21, the radial channel 112 is located at the upper part of the sealing sleeve 14, and the guide hole 141 corresponds to the liquid flow channel 24. A thread 18 connected to the control pipeline joint 4 is provided at the upper end of the axial channel 111. At this time, hydraulic oil can be input into the hydraulic chamber through the control pipeline, Figure 5 The arrow direction in the figure is the flow direction of the hydraulic oil when the safety valve 2 is to be opened. The hydraulic oil enters the radial channel 112 through the axial channel 111 and then enters the guide hole 141 and the liquid flow channel 24 corresponding to the guide hole 141 through the gap between the main body 11 and the sealing sleeve 14, and then enters the hydraulic cavity to open the safety valve 2. When an accident occurs and the safety valve 2 needs to be closed, the ground control stops supplying liquid to the hydraulic cavity 3, and then the control pipeline is pulled up to break the second limit shear nail 17, and the main body 11 is pulled out of the docking hole 21. Figure 6 As shown, the pressure relief of the hydraulic chamber 3 is achieved, and the safety valve is automatically closed. The docking device 1 can achieve three functions: 1. Achieve sealed docking with the inside of the housing of the safety valve 2; 2. When the docking device 1 is sealed and installed in the docking hole 21, it can be connected with the hydraulic chamber 3, and hydraulic oil is input through the control pipeline to achieve the opening of the safety valve 2; 3. By pulling the main body 11 out of the docking hole 21, the hydraulic chamber 3 is depressurized to achieve the closing of the safety valve 2.

[0051] In this embodiment, the inner wall and the outer wall of the lower part of the sealing sleeve 14 are both provided with a second sealing groove, and the second sealing ring 142 is installed in the second sealing groove to ensure the sealing of the sealing sleeve 14 with the main body 11 and the second hole section 212.

[0052] In this embodiment, the shear force of the first limit shear nail 15 is smaller than the shear force of the second limit shear nail 17, so as to prevent the second limit shear nail 17 from being broken when the docking connector 1 and the safety valve 2 are sealed and docked.

[0053] like Figure 2 , 4 , 6, and 7 show the docking process of the docking device 1 and the safety valve 2 in this embodiment:

[0054] Safety valve 2 entering the well process: Figure 7As shown, after the control line 5 is connected to the docking device 1 through the control line joint 4, it is suspended in the docking hole 21 in the housing of the safety valve 2. The safety valve 2 is sealed by the sliding sleeve 22. At this time, the clamping ring 12 and the sealing ring 13 are respectively inserted into the clamping ring groove and the sealing ring groove provided on the main body 11;

[0055] The docking of the docking device 1 and the safety valve 2 and the opening process of the safety valve 2: After the oil pipe string is lowered, the control pipeline 5 is salvaged by the salvaging device 7 located in the oil pipe 6 and a certain pulling force is applied, wherein the salvaging head 71 is used to transmit the salvaging power, and the straightener 72 is used to correct the salvaging path. The docking device 1 connected to the lower end of the control pipeline 5 is docked with the docking hole 21 of the housing of the safety valve 2, as shown in FIG. Figure 4 As shown, during the docking process, the sleeve 22 moves upward, the docking device 1 seals the liquid flow channel 24, and then the main body 11 is lifted up through the control pipeline 5, and the docking device 1 is fixed through the first limit shear nail 15. At this time, the clamping ring 12 is disengaged from the clamping ring groove, the control system of the wellhead downhole control pipeline 5 is connected and the wellhead is installed and put into production, and hydraulic oil is input into the hydraulic chamber 3 through the control pipeline 5 through the axial channel 111 and the radial channel 112, and the safety valve 2 is opened;

[0056] The process of closing the safety valve 2 and lifting the pipe string: dismantle the wellhead, increase the force to lift the control pipeline 5, so that the second limit shear nail 17 fixed on the docking device 1 is pulled off, the limit sleeve 16 falls off from the main body 11, the main body 11 escapes from the docking hole 21, and the hydraulic oil flows out from the liquid flow channel 24 to the inside of the housing of the safety valve 2, completing the pressure relief of the hydraulic chamber 3, and the safety valve 2 closes automatically. In this way, since there is no influence of the fixed control pipeline clip, it is very convenient and quick to lift the downhole pipe string and supporting tools during the blowout prevention operation, which greatly reduces the construction difficulty and safety risks and improves work efficiency.

[0057] Example 2

[0058] like Figure 8-11 As shown, this embodiment is an improvement on the docking device 1 based on the embodiment 1. Correspondingly, the structure of the safety valve 2 is also adaptively improved. The improvement lies in that an infusion channel 26 connected to the hydraulic chamber 3 is provided on the shell of the safety valve 2. The infusion channel 26 is connected to the end surface of the shell of the safety valve 2. The sealing member 27 is installed in the infusion channel 26 from the end surface side of the shell. The sealing member 27 in this embodiment is a wire plug, that is, hydraulic oil is transported to the hydraulic chamber 3 through the infusion channel to realize the opening of the safety valve 2; the docking device 1 is sealed and docked when the safety valve 2 is opened, and the hydraulic chamber is depressurized when the safety valve 2 needs to be opened.

[0059] like Figure 8 , 10 , 11, reflects the docking and use process of the docking device 1 and the safety valve 2 in this embodiment:

[0060] Safety valve 2 entering the well process: Figure 8 As shown, after the control line 5 is connected to the docking device 1 through the control line joint 4, it is suspended in the docking hole 21 in the housing of the safety valve 2. The safety valve 2 is sealed by the sliding sleeve 22. At this time, the clamping ring 12 and the sealing ring 13 are respectively inserted into the clamping ring groove and the sealing ring groove provided on the main body 11;

[0061] The docking of the docking device 1 and the safety valve 2 and the opening process of the safety valve 2: After the oil pipe string is lowered, the control pipeline 5 is salvaged by the salvaging device 7 located in the oil pipe 6 and a certain pulling force is applied, wherein the salvaging head 71 is used to transmit the salvaging power, and the straightener 72 is used to correct the salvaging path. The docking device 1 connected to the lower end of the control pipeline 5 is docked with the docking hole 21 of the housing of the safety valve 2, as shown in FIG. Figure 4 As shown, during the docking process, the sleeve 22 moves upward, the docking device 1 seals the liquid flow channel 24, and then the main body 11 is lifted up through the control pipeline 5, and the docking device 1 is fixed through the first limit shear nail 15. At this time, the clamping ring 12 is disengaged from the clamping ring groove, the control system of the wellhead and downhole control pipeline 5 is connected and the wellhead is installed and put into production, the plug on the infusion channel 26 is opened, hydraulic oil is input into the hydraulic chamber 3, and the safety valve 2 is opened. After the safety valve 2 is opened, the infusion channel 26 is closed again by the plug;

[0062] The process of closing the safety valve 2 and lifting the pipe string: dismantle the wellhead, increase the force to lift the control pipeline 5, so that the second limit shear nail 17 fixed on the docking device 1 is pulled off, the limit sleeve 16 falls off from the main body 11, the main body 11 escapes from the docking hole 21, and the hydraulic oil flows out from the liquid flow channel 24 to the inside of the housing of the safety valve 2, completing the pressure relief of the hydraulic chamber 3, and the safety valve 2 closes automatically. In this way, since there is no influence of the fixed control pipeline clip, it is very convenient and quick to lift the downhole pipe string and supporting tools during the blowout prevention operation, which greatly reduces the construction difficulty and safety risks and improves work efficiency.

[0063] In the above process, the docking device 1 can achieve sealing with the safety valve 2 to ensure the opening of the safety valve 2, and can also relieve pressure in the hydraulic chamber 3 to achieve the closing of the safety valve 2.

[0064] Example 3

[0065] like Fig.12As shown, this embodiment is based on the embodiment 1, and improves the structure of the safety valve 2 and the docking device. The improvement is that the docking hole 21 is connected with the liquid flow channel 24, but does not penetrate the inner boss 28. Before the pipe string is lowered into the well, the sealing of the docking device and the docking hole 21 must be completed. The docking device here can be a screw connected to the control pipeline 5, or a connecting joint connected to the control pipeline 5, etc. When the safety valve 2 needs to be closed, the docking device is also removed from the docking hole 21, and the hydraulic oil also flows into the interior of the safety valve 2 along the liquid flow channel 24 to complete the pressure relief of the hydraulic chamber 3, and the safety valve 2 closes automatically. In this way, since there is no influence of the fixed control pipeline clip, it is very convenient and quick to pull out the downhole pipe string and the supporting tools in the blowout prevention operation, which greatly reduces the construction difficulty and safety risks and improves work efficiency.

[0066] It should be noted that the "up" and "down" mentioned in the above implementation refer to the relative directions of the docking device 1 and the safety valve 2 when in use. As in the existing design of the hydraulic control pipeline on the outer wall of the oil pipe, when the safety production device of the above embodiment needs to close the downhole installation valve, it is not necessary to disconnect the docking device 1 from the docking hole 21. Instead, the hydraulic chamber 3 is depressurized through the control pipeline 5 by the ground control system. After the pressure is released, the piston of the safety valve 2 moves upward under the action of the spring force, and the safety valve 2 is closed. Only when the production pipe string needs to be pulled out during the well repair process, the ground control system lifts the control pipeline 5 through the equipment.

[0067] Finally, it is understood that the above embodiments are merely exemplary embodiments used to illustrate the principles of the present invention, but the present invention is not limited thereto. For those of ordinary skill in the art, various modifications and improvements can be made without departing from the principles and essence of the present invention, and these modifications and improvements are also considered to be within the scope of protection of the present invention.

Claims

1. An underground production safety device, characterized in that: include: Safety valves, docking stations and control lines; The safety valve comprises: a housing, a piston assembly and a valve plate both mounted in the housing; a hydraulic cavity is formed between the upper end of the piston assembly and the housing, and the lower end of the piston assembly cooperates with the valve plate; a liquid flow channel communicating with the hydraulic cavity is provided on the housing, and a docking hole communicating with the liquid flow channel is also provided in the housing; The control pipeline is located in the pipe column, one end of the control pipeline is connected to the control device arranged at the wellhead, and the other end of the control pipeline is connected to the docking device; the docking device is sealed and docked in the docking hole; a sleeve is also installed in the docking hole of the safety valve, and the outer wall of the sleeve fits with the inner wall of the docking hole, the docking hole includes a first hole section located at the upper part and a second hole section located at the lower part, the inner diameter of the first hole section is smaller than the inner diameter of the second hole section, the second hole section is connected to the liquid flow channel, the sleeve is installed in the second hole section and fits with the inner wall of the second hole section; the docking device includes: a main body matched with the first hole section, a sealing sleeve mounted on the lower part of the main body, a retaining ring, a sealing ring, a limit sleeve, a first limit shear nail and a second limit shear nail; the outer diameter of the sealing sleeve matches the second hole section; the sealing sleeve is provided with a radial first positioning hole, and the first limit shear nail passes through the first positioning hole to fix the sealing sleeve to the main body.

2. The underground production safety device according to claim 1, characterized in that: Shear pins for limiting the position of the sliding sleeve are also installed in the docking hole, so that the sliding sleeve closes the liquid flow channel.

3. The underground production safety device according to claim 2, characterized in that: An inner boss is arranged in the outer shell above the hydraulic chamber, and the docking hole passes through the inner boss.

4. The underground production safety device according to claim 1, characterized in that: First sealing grooves are provided on both upper and lower sides of the inner wall of the second hole section connected to the liquid flow channel. The first sealing groove is located at the matching position of the second hole section and the sliding sleeve. A first sealing ring is installed in the first sealing groove.

5. The underground production safety device according to claim 3, characterized in that: A snap ring groove and a sealing ring groove are provided on the outer wall of the main body, the distance between the upper end surface of the sealing sleeve and the snap ring groove is greater than the sum of the axial lengths of the first hole section and the sliding sleeve, the sealing ring groove is provided between the snap ring groove and the sealing sleeve, the distance between the snap ring groove and the sealing ring groove is less than the axial length of the first hole section, the snap ring and the sealing ring are respectively installed in the snap ring groove and the sealing ring groove; an infusion channel connected to the hydraulic chamber is provided on the outer shell of the safety valve, and the infusion channel is connected to the end surface of the outer shell.

6. The underground production safety device according to claim 5, characterized in that: The docking device also includes an annular limiting sleeve and a second limiting shear nail, the outer diameter of the limiting sleeve is larger than the inner diameter of the second hole section, the limiting sleeve is provided with a radial second positioning hole, the second limiting shear nail passes through the second positioning hole to fix the limiting sleeve to the lower end of the main body, and the distance from the upper end surface of the limiting sleeve to the retaining ring groove is greater than or equal to the thickness of the inner boss.

7. The underground safety production device according to claim 5 or 6, characterized in that: An axial liquid flow channel and a radial liquid flow channel communicating with the axial liquid flow channel are arranged in the main body of the docking device, the axial liquid flow channel passes through the upper end surface of the main body, and the radial liquid flow channel radially passes through the main body; the inner wall of the lower part of the sealing sleeve is in contact with the outer wall of the main body, and there is a gap between the upper part of the sealing sleeve and the outer wall of the main body, and radial guide holes are also arranged on the upper part of the sealing sleeve; when the docking device is sealed and installed in the docking hole, the radial liquid flow channel is located on the upper part of the sealing sleeve, and the guide hole corresponds to the liquid flow channel.

8. The underground production safety device according to claim 7, characterized in that: The inner wall and the outer wall of the lower part of the sealing sleeve are both provided with a second sealing groove, and the second sealing ring is installed in the second sealing groove.

9. The underground safety production device according to claim 1 or 2, characterized in that: The shell of the safety valve is provided with a liquid infusion channel connected with the hydraulic chamber. The liquid infusion channel is connected to the end surface of the shell. A sealing member is installed in the liquid infusion channel from the end surface side of the shell.

10. The underground safety production device according to claim 5, characterized in that: The shear force of the first position-limiting shear nail is smaller than the shear force of the second position-limiting shear nail.

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