A jet device for cutting inside a downhole drilling tool

Abstract

The present invention relates to the technical field of downhole pipe string cutting, and in particular to a jet device for cutting in downhole drilling tools, comprising a shell, the inner wall of the shell is provided with a heat insulating lining, a nozzle fixedly connected to the shell is provided below the heat insulating lining, a plurality of jet channels are vertically opened on the nozzle, the jet channels are arranged along the circumference of the nozzle, and the jet channels are in the shape of an arc, consisting of two concentric arcs and arcs at both ends; a guide cone is installed at the axis of the upper end of the nozzle; a diverter is connected to the lower end of the nozzle, the side wall of the diverter is provided with an arc surface for guiding the vertically sprayed flame to spray horizontally, and the diverter is also provided with a plurality of nozzles connected to the arc surface. Through this device, the problems of long cutting time and poor cutting effect can be effectively solved.

Description

Technical Field

[0001] The invention relates to the technical field of downhole pipe string cutting, in particular to a jet device for cutting inside a downhole drilling tool. Background Art

[0002] At present, there are many types of downhole pipe cutting tools. In recent years, the working rules and application of downhole pipe cutting tools have become a hot topic of research. The current cutting methods are mainly divided into: chemical cutting, continuous pipe energy cutting, arc cutting and hydraulic cutting. Chemical cutting, the incision of this method is relatively smooth, the cutting speed is fast, and there will be no residual cutting debris, which is more beneficial for further operation. However, there is a large amount of environmental pollution, the amount of chemical reagents is not easy to control, and the corrosive solution will cause corrosion of the casing during the splashing process, which will cause hidden dangers in the well repair operation. For horizontal wells and highly deviated oil wells, it is difficult to transport the equipment to the well by cable. There are strict restrictions on the distance between the equipment and the inner wall of the cutting pipe, and chemical reagents are also dangerous. Continuous pipe energy cutting uses explosives to spray metal particles to cut the pipe. After the cutting is completed, the continuous oil pipe can quickly establish a channel with the cut pipe for well fluid circulation, which has less environmental pollution and can greatly shorten the operation cycle. However, due to the excessive power of the explosive explosion, the shape of the pipe string cut after cutting is very irregular, and a trumpet-shaped cut will be formed. If the amount of explosives is too large, the outer casing of the oil pipe will be damaged. Due to the large vibration caused by the explosion, the pipe string and equipment will be damaged to a certain extent. When the amount of explosives is relatively small, the pipe string cutting effect will be poor or even no cutting will occur. Arc cutting uses the interaction between two electrodes to generate arc discharge to process materials. However, it requires high technical requirements, which is also the reason why its use is limited. Hydraulic cutting uses a mechanical cutting knife to cut the pipeline. It requires a more complex mechanical structure, which greatly increases the probability of problems, and the working environment and inner cavity space limit its application scenarios.

[0003] Based on the shortcomings of the above-mentioned cutting technologies, a new type of cutting technology has emerged: pyrotechnic cutting, which uses the high temperature generated by thermite to directly act on the inner wall of the pipe column to achieve the purpose of cutting.

[0004] In the prior art, a Chinese invention patent document with publication number CN101619649A and publication date January 6, 2010 is proposed. The technical solution disclosed in the patent document is as follows: a non-explosive metal tube annular cutting device, which uses the high temperature generated by the combustion of the burning agent as a power source, and can cut the metal tube along the circumferential direction. It is mainly composed of structures such as an upper joint, a charging chamber, a fluid distribution guide, a steering gear, a sealing sleeve and a tail frame. After the burning agent in the charging chamber is ignited, the generated high-temperature fluid flows along the axial direction of the device toward the direction of the fluid distribution guide. After the high-temperature fluid passes through the fluid distribution guide, it is turned by the steering gear, and its movement direction is smoothly transformed into a radial direction perpendicular to the axial direction of the device. At the same time, under the action of pressure, the sealing sleeve slides toward the tail of the device to open the cutting channel. The high-temperature fluid directly acts on the inner surface of the cut metal tube, thereby realizing the cutting operation.

[0005] The above technical solution may cause the following problems during actual use:

[0006] This solution uses a circular hole-shaped diversion channel, which cannot control the heat well. The heat is easily dissipated intermittently during the cutting process, resulting in a long cutting time and poor cutting effect. Summary of the invention

[0007] In order to solve the above technical problems, the present invention proposes a jet device for cutting inside a downhole drilling tool, which can effectively solve the problems of long cutting time and poor cutting effect.

[0008] The present invention is achieved by adopting the following technical solutions:

[0009] A jet device for cutting inside a downhole drill tool comprises a shell, the inner wall of which is provided with a heat-insulating lining, and is characterized in that: a nozzle fixedly connected to the shell is provided below the heat-insulating lining, a plurality of jet channels are vertically opened on the nozzle, the jet channels are arranged along the circumference of the nozzle, and the jet channels are in an arc shape, consisting of two concentric arcs and arcs at both ends; a guide cone is installed at the axis of the upper end of the nozzle; a diverter is connected to the lower end of the nozzle, the side wall of the diverter is provided with an arc surface for guiding the vertically injected flame to be injected horizontally, and the diverter is also provided with a plurality of nozzles connected to the arc surface.

[0010] A heat-resistant support seat is arranged between the heat-insulating lining and the nozzle, and the opening size of the upper end of the heat-resistant support seat is larger than the opening size of the lower end.

[0011] The number of the injection channels is four.

[0012] The angle corresponding to the arc length of the two concentric circles in the injection channel is 55°, and the distance between the two concentric circles is 5 mm.

[0013] The nozzle and the diverter are detachably connected.

[0014] A fixing piece is arranged at the axis of the nozzle, and the flow divider is detachably connected to the nozzle via the fixing piece.

[0015] The lower end of the diverter is connected to a support member, a sleeve is movably mounted on the support member, the upper end of the sleeve is movably mounted on the shell, a sealing ring in contact with the sleeve is mounted on the support member and the shell, and exhaust channels are respectively arranged between the sleeve and the nozzle, the diverter and the support member.

[0016] The support member is a T-shaped structure, a cavity is provided between the sleeve and the lower surface of the head of the T-shaped structure, and the cavity is communicated with the exhaust passage.

[0017] The lower end of the support member is connected with a stopper.

[0018] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0019] 1. In the present invention, the heat enters the injection channel at a high speed through the drainage effect of the drainage cone, avoiding the heat directly hitting the end face of the nozzle to weaken the movement speed of the heat. The speed of heat movement increases through the injection channel on the nozzle, and the arc surface guides the high-speed moving heat to the horizontal direction, and the heat is sprayed around along the circumference of the diverter, thereby acting on the inner wall of the pipe column, ensuring the cutting effect and keeping the incision smooth.

[0020] Furthermore, the arc of the injection channel is composed of two concentric arcs and small arcs at both ends. Compared with the circular hole structure, the injection channel with an arc structure is more conducive to the concentration of speed and is not easy to disperse intermittently during the cutting process. Although the injection channel with an arc structure will lead to a decrease in cutting speed, it is because the increase in the width of the pipeline will lead to a slow increase in speed. However, in this application, through the arc surface set on the side wall of the diverter and the nozzle connected to the arc surface, the nozzle can perform the final acceleration of the heat after the change of direction is completed to make up for the speed lost during the heat change of direction, thereby ensuring the heat for the cutting of the inner wall of the pipe column.

[0021] Therefore, by utilizing the nozzle, the injection channel on the nozzle, the curved surface on the diverter, and the nozzle, the spray device can be stable during operation, and the high-temperature fireworks can continuously cut the inner wall of the pipe column in a continuous cutting manner and reach the inner wall of the pipe column at a sufficient speed to ensure the cutting effect.

[0022] 2. The opening size of the upper end of the heat-resistant support seat is larger than that of the lower end, so that the heat-resistant support seat forms a conical channel, which is used to initially increase the speed of heat movement and further improve the disadvantage of reduced cutting speed caused by the use of an arc-structured jet channel.

[0023] 3. The angle corresponding to the arc length of the two concentric circles in the injection channel is 55°, and the distance between the two concentric circles is 5 mm, which can not only ensure the stability of the injection device during operation, but also enable the high-temperature fireworks to continuously cut the inner wall of the pipe column in a continuous cutting manner and reach the inner wall of the pipe column at a sufficient speed.

[0024] 4. The nozzle and the diverter are detachably connected, which is convenient for replacing corresponding accessories in subsequent maintenance and reduces maintenance costs.

[0025] 5. The sleeve can be set to seal the shell to prevent moisture in the pipe column from entering the shell and affecting the combustion of thermite. By setting the exhaust channel, when thermite starts to burn, high-pressure gas will flow into the exhaust channel, thereby driving the sleeve to move in the direction of leaving the shell, and finally leak out of the nozzle to achieve cutting of the inner wall of the pipe column. The sealing rings set at the upper and lower ends of the sleeve seal the gap to prevent the sleeve from being driven open due to leakage of high-pressure gas.

[0026] 6. A cavity is provided between the sleeve and the lower surface of the head of the T-shaped structure, so that the high-pressure gas can better drive the sleeve to move, ensuring that the sleeve is separated from the shell in time to avoid affecting the cutting operation and avoiding explosion at the sleeve due to failure to discharge the gas in time.

[0027] 7. The setting of the stopper can block the sleeve from falling off, preventing the sleeve from falling to the lower end of the injection device and affecting the operation of other structures of the cutting device. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments, wherein:

[0029] Figure 1 It is a structural schematic diagram of the present invention;

[0030] Figure 2 It is a schematic plan view of the injection channel in the present invention;

[0031] Markings in the figure:

[0032] 1. Insulation lining, 2. Shell, 3. Heat-resistant support seat, 4. Drainage cone, 5. Nozzle, 6. Injection channel, 7. Sealing ring, 8. Nozzle, 9. Fixing part, 10. Diverter, 11. Exhaust channel, 12. Sleeve, 13. Support part, 14. Cavity, 15. Baffle. DETAILED DESCRIPTION

[0033] Example 1

[0034] As a basic embodiment of the present invention, the present invention includes a jet device for cutting inside a downhole drilling tool, including a shell 2, the inner wall of which is provided with a heat insulating lining 1. A nozzle 5 fixedly connected to the shell 2 is provided below the heat insulating lining 1. A plurality of jet channels 6 are vertically opened on the nozzle 5, and the jet channels 6 are arranged along the circumference of the nozzle 5, and the jet channels 6 are in an arc shape, consisting of two concentric arcs and small arcs at both ends. In this embodiment, the number of the jet channels 6 is not limited.

[0035] A guide cone 4 is installed at the axis center of the upper end of the nozzle 5. A diverter 10 is connected to the lower end of the nozzle 5, and the side wall of the diverter 10 is provided with an arc surface for guiding the vertically sprayed flame to be sprayed horizontally, and the diverter 10 is also provided with a plurality of nozzles 8 connected to the arc surface.

[0036] This embodiment utilizes the nozzle 5, the injection channel 6 on the nozzle 5, the curved surface on the diverter 10, and the nozzle 8 to cooperate with each other. The nozzle 8 can perform a final acceleration on the heat after the change of direction is completed to make up for the speed lost during the heat change of direction, thereby ensuring that the instantaneously generated heat is directed to the inner wall of the pipe column at a high speed, so that the heat is quickly concentrated on the inner wall of the pipe column, ensuring the cutting effect.

[0037] Example 2

[0038] As a preferred embodiment of the present invention, the present invention includes a jet device for cutting inside a downhole drilling tool, including a shell 2, the inner wall of which is provided with a heat-insulating lining 1. A nozzle 5 fixedly connected to the shell 2 is provided below the heat-insulating lining 1, and a plurality of jet channels 6 are vertically opened on the nozzle 5, the jet channels 6 are arranged along the circumference of the nozzle 5, and the jet channels 6 are in an arc shape, consisting of two concentric arcs and small arcs at both ends.

[0039] A guide cone 4 is installed at the axis center of the upper end of the nozzle 5. A diverter 10 is connected to the lower end of the nozzle 5, and the side wall of the diverter 10 is provided with an arc surface for guiding the vertically sprayed flame to be sprayed horizontally, and the diverter 10 is also provided with a plurality of nozzles 8 connected to the arc surface.

[0040] The lower end of the diverter 10 is connected to a support member 13, on which a sleeve 12 is movably mounted, and the upper end of the sleeve 12 is movably mounted on the shell 2. A sealing ring 7 in contact with the sleeve 12 is mounted on the support member 13 and the shell 2, and an exhaust channel 11 is respectively provided between the sleeve 12 and the nozzle 8, the diverter 10, and the support member 13.

[0041] The support member 13 is a T-shaped structure. A cavity 14 is provided between the sleeve 12 and the lower surface of the head of the T-shaped structure. The cavity 14 is communicated with the exhaust passage 11 .

[0042] Example 3

[0043] As the best embodiment of the present invention, refer to the attached specification Figure 1 And the instruction manual Figure 2 The present invention includes a jet device for cutting inside a downhole drilling tool, including a shell 2, the inner wall of which is provided with a heat-insulating lining 1. The heat-insulating lining 1 contains an aluminothermic material for releasing heat. A nozzle 5 fixedly connected to the shell 2 is provided below the heat-insulating lining 1, and four jet channels 6 are vertically opened on the nozzle 5. Figure 2 The injection channel 6 is arranged along the circumference of the nozzle 5, and the injection channel 6 is in an arc shape, consisting of two concentric arcs and small arcs at both ends. More specifically, the angle r corresponding to the arc length of the two concentric arcs in the injection channel 6 is 55°, and the distance d between the two concentric arcs is 5mm, which can not only ensure the stability of the injection device when working, but also enable the high-temperature fireworks to continuously cut the inner wall of the column in a continuous cutting manner, and reach the inner wall of the column at a sufficient speed.

[0044] Compared with the circular hole structure, the arc-shaped injection channel 6 is more conducive to the concentration of speed and is not easy to disperse intermittently during the cutting process. However, this method will lead to a decrease in cutting speed, because the increase in the width of the pipeline will lead to a slow increase in speed. In order to ensure continuous cutting, the injection channel 6 should be selected as an arc structure. In order to ensure the movement speed of heat, the internal pressure of the tool can be appropriately increased during operation to increase the injection speed.

[0045] A heat-resistant support seat 3 is arranged between the heat-insulating liner 1 and the nozzle 5, and the upper end opening size of the heat-resistant support seat 3 is larger than the lower end opening size, wherein the upper end specifically refers to the end close to the heat-insulating liner 1. The heat-resistant support seat 3 and the heat-insulating liner 1 are made of high-purity graphite. The heat-resistant support seat 3 has a tapered channel, which is used to initially increase the speed of heat movement.

[0046] A guide cone 4 is installed at the axis center of the upper end of the nozzle 5, and a diverter 10 is connected to the lower end of the nozzle 5. More specifically, a fixing member 9 is provided at the axis center of the nozzle 5, and the diverter 10 is detachably connected to the nozzle 5 through the fixing member 9. The diverter 10 is detachably connected to the nozzle 5, which can facilitate the replacement of corresponding accessories in subsequent maintenance and reduce maintenance costs.

[0047] The side wall of the diverter 10 is provided with an arc surface for guiding the vertically sprayed flame to spray horizontally, and the diverter 10 is also provided with a plurality of nozzles 8 connected to the arc surface. The guide cone 4, the nozzle 5, the nozzle 8 and the diverter 10 are all made of tungsten alloy. The nozzle 8 can be provided to accelerate the heat after the change of direction is completed, so as to make up for the speed lost during the heat change of direction, thereby ensuring that the heat cuts the inner wall of the pipe string.

[0048] The lower end of the diverter 10 is connected to a support 13, on which a sleeve 12 is movably sleeved, and the upper end of the sleeve 12 is movably sleeved on the shell 2. The support 13 and the shell 2 are sleeved with a sealing ring 7 in contact with the sleeve 12, and an exhaust channel 11 is provided between the sleeve 12 and the nozzle 8, the diverter 10, and the support 13. The sleeve 12 can be provided to seal the shell 2 to prevent moisture in the pipe column from entering the shell 2 and affecting the combustion of thermite. By providing the exhaust channel 11, when thermite just starts to burn, high-pressure gas will flow into the exhaust channel 11, thereby driving the sleeve 12 to move in the direction of leaving the shell 2, and finally leak out of the nozzle 8 to achieve cutting of the inner wall of the pipe column. The sealing rings 7 provided at the upper and lower ends of the sleeve 12 seal the gap to prevent the sleeve 12 from being driven open due to leakage of high-pressure gas.

[0049] The support member 13 is a T-shaped structure, and a cavity 14 is provided between the sleeve 12 and the lower surface of the head of the T-shaped structure, and the cavity 14 is connected to the exhaust channel 11. The cavity 14 can make the high-pressure gas drive the sleeve 12 to move better, ensure that the sleeve 12 is separated from the housing 2 in time, avoid affecting the cutting operation, and avoid explosion at the sleeve 12 due to the failure of timely discharge of gas.

[0050] The lower end of the support member 13 is connected with a stopper 15. The stopper 15 can be provided to stop the sleeve 12 from falling off, so as to prevent the sleeve 12 from falling to the lower end of the injection device and affecting the work of other structures of the cutting device.

[0051] After the injection device moves to a suitable position, the thermite is ignited, and the thermite instantly generates high temperature, forcing the gas in the shell 2 to pass through the exhaust channel 11 at high speed and enter the cavity 14. The sleeve 12 quickly separates from the shell 2, and the subsequent high-temperature fireworks enter the injection channel 6 at high speed through the guidance of the guide cone 4. After being turned by the arc surface, the high-temperature fireworks are ejected horizontally from the nozzle 8, and the inner wall of the pipe column is cut by the high-temperature and high-speed fireworks.

[0052] In summary, after reading the present invention document, ordinary technicians in this field can make various other corresponding transformation schemes based on the technical scheme and technical concept of the present invention without creative mental labor, which all fall within the scope of protection of the present invention.

Claims

1. A jetting device for cutting inside a downhole drilling tool, comprising a housing (2), the inner wall of the housing (2) being provided with a heat insulating lining (1), characterized in that: A nozzle (5) fixedly connected to the shell (2) is arranged below the thermal insulation lining (1), and a plurality of injection channels (6) are vertically opened on the nozzle (5), and the injection channels (6) are arranged along the circumference of the nozzle (5), and the injection channels (6) are in the shape of an arc, consisting of two concentric arcs and arcs at both ends; a guide cone (4) is installed at the axis of the upper end of the nozzle (5); a diverter (10) is connected to the lower end of the nozzle (5), and a side wall of the diverter (10) is provided with an arc surface for guiding the vertically injected flame to be injected horizontally, and the diverter (10) is also provided with a plurality of nozzles (8) connected to the arc surface; a heat-resistant support seat is provided between the thermal insulation lining (1) and the nozzle (5). (3), the opening size of the upper end of the heat-resistant support seat (3) is larger than the opening size of the lower end; the lower end of the diverter (10) is connected to a support member (13), a sleeve (12) is movably sleeved on the support member (13), the upper end of the sleeve (12) is movably sleeved on the shell (2), the support member (13) and the shell (2) are sleeved with a sealing ring (7) in contact with the sleeve (12), and an exhaust channel (11) is provided between the sleeve (12) and the nozzle (8), the diverter (10), and the support member (13); the support member (13) is a T-shaped structure, a cavity (14) is provided between the sleeve (12) and the lower surface of the head of the T-shaped structure, and the cavity (14) is connected to the exhaust channel (11).

2. A jetting device for cutting inside a downhole drilling tool according to claim 1, characterized in that: The number of the injection channels (6) is four.

3. A jetting device for cutting inside a downhole drilling tool according to claim 2, characterized in that: The angle corresponding to the arc length of the two concentric circles in the injection channel (6) is 55°, and the distance between the two concentric circles is 5 mm.

4. A jetting device for cutting inside a downhole drilling tool according to claim 1 or 3, characterized in that: The nozzle (5) and the flow divider (10) are detachably connected.

5. A jetting device for cutting inside a downhole drilling tool according to claim 4, characterized in that: A fixing member (9) is provided at the axis of the nozzle (5), and the flow divider (10) is detachably connected to the nozzle (5) via the fixing member (9).

6. A jetting device for cutting inside a downhole drilling tool according to claim 5, characterized in that: The lower end of the support member (13) is connected to a stopper (15).

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