High-temperature melting cutting tool pressurized by drilling fluid

Abstract

The present invention belongs to the technical field of oil drilling equipment and relates to a high-temperature melting cutting tool pressurized by drilling fluid, which mainly consists of a controller, a push cylinder, a slider, a fuse, a slider, a flow guide, a tool housing, a high-temperature resistant piston, a graphite heat insulation layer, a charge, a steering nozzle, and a sleeve. The controller is connected to the charge through the fuse to ignite it. After the charge is ignited for 2 seconds, the controller sends a signal to the push cylinder, and the push cylinder pushes the slider downward. The slider hole is aligned with the flow channel hole of the flow guide, and the drilling fluid flows into the interior of the tool housing through the flow channel hole of the flow guide due to the internal and external pressure difference. The pressure of the drilling fluid pushes the high-temperature resistant piston downward, squeezing the internal space of the tool housing, generating pressure to better discharge the high-temperature gas generated by the high-temperature melting reaction from the tool, achieving a better cutting effect. The structure of the present invention is simple, which can improve the melting cutting efficiency of the drill pipe, reduce the difficulty of subsequent drill string recovery operations, and lower the recovery cost.

Description

Technical Field

[0001] The present invention belongs to the technical field of oil drilling equipment and relates to a high-temperature melting cutting tool pressurized by drilling fluid. Background Art

[0002] In recent years, with the increase in the production volume of oil and gas wells in China, the mining difficulty has become greater and greater. Along with the increase in mining difficulty, during construction operations such as drilling and production, the accident rate of metal pipe strings such as drill pipes, tubing, or other casing pipes getting stuck also increases. Downhole special perforation technology can quickly and reasonably solve the stuck accidents, minimize economic losses as much as possible, and ensure the normal progress of oil and gas well production and construction. Otherwise, the oil and gas wells can only be scrapped, resulting in huge economic losses. Currently, commonly used means for cutting downhole pipe strings include mechanical, explosive cutting, chemical cutting, etc. After chemical cutting, it is easy to damage other surrounding pipe strings; existing mechanical cutting has some uncertainties in operation and limitations in capabilities; explosive cutting has regulatory requirements and requires handling relevant permits, which will affect the process progress. The melting cutting tool uses the thermite reaction to spray the generated high-temperature molten metal onto the drill pipe and ablates the drill pipe with high temperature. The process is efficient and reliable and does not require handling relevant permits. Moreover, this technology can adjust the charge amount according to the thickness of the drill pipe and will not damage the outer pipe string of the perforated pipe string. Summary of the Invention

[0003] The object of the present invention is to improve the efficiency of the high-temperature melting cutting tool through the pressure difference inside and outside the tool, and it can achieve efficient and safe cutting of downhole pipe strings in a small space to complete the recovery of downhole drilling tools.

[0004] The technical solution adopted by the present invention is as follows:

[0005] The present invention is a high-temperature melting cutting tool pressurized by drilling fluid, mainly composed of a controller, a push cylinder, a slider, a fuse, a slider, a flow guide, a tool housing, a high-temperature resistant piston, a sealing material, a graphite heat insulation layer, a charge column, a connecting nipple, a steering nozzle, and a sleeve. Its characteristics are as follows: The upper part of the tool is the control part, mainly composed of a controller housing and a controller. The controller is connected to the ignition charge column through a fuse, and the controller hydraulically controls the push cylinder below. The push cylinder is installed inside the push cylinder housing; a slider is connected to the end of the push cylinder. A channel is opened in the slider, and a sealing ring is provided; the flow guide is provided with two channels, one for passing the fuse, and the other is the drilling fluid inlet; a graphite heat insulation layer is installed inside the tool housing, and a high-temperature resistant piston is provided at the upper part. A hole is opened in the middle of the high-temperature piston. After passing the fuse, it is blocked with a sealing material, and the charge column is placed below; the flow guide is installed inside the connecting nipple. The flow channel is connected to the steering nozzle and the recovery rod through a connecting rod. A sealing ring is provided between the connecting nipple and the sliding sleeve.

[0006] The controller ignites the propellant through a fuse wire. The propellant reacts to generate a large amount of gas and extremely high temperature. The initially generated gas will flow out along the steering nozzle to push the sliding sleeve downward, exposing the steering nozzle. As the reaction of the agent proceeds, the high-temperature molten metal is pushed by the high-temperature gas and flows downward to the deflector for splitting, and then is ejected from the steering nozzle to the drill pipe wall to complete the cutting operation. After the propellant is ignited for 2 seconds, the controller sends a signal to the push cylinder. The push cylinder pushes the slider downward, and the slider flow channel hole is aligned with the deflector flow channel hole. Due to the internal and external pressure difference, the drilling fluid flows into the interior of the tool housing through the deflector flow channel hole. The pressure of the drilling fluid pushes the high-temperature resistant piston downward, squeezing the internal space of the tool housing, generating pressure to better discharge the high-temperature gas generated by the high-temperature molten reaction from the tool, achieving a better cutting effect.

[0007] Compared with the prior art, the beneficial effects of the present invention are as follows: Through the internal and external pressure difference of the tool, high-temperature gas pressurized jet cutting is realized, improving the cutting efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 is a schematic diagram of the overall structure of the high-temperature molten cutting tool using drilling fluid pressurization according to the present invention;

[0009] Figure 2 is a schematic diagram of the overall structure of the high-temperature molten cutting tool using drilling fluid pressurization after pressurization according to the present invention;

[0010] Figure 3 is a schematic diagram of the structural comparison of the drainage mechanism before and after pressurization according to the present invention;

[0011] Figure 4 is a schematic diagram of the structure of the high-temperature resistant piston according to the present invention;

[0012] Figure 5 is a schematic diagram of the structure of the slider according to the present invention;

[0013] Figure 6 is a schematic diagram of the structure of the deflector according to the present invention;

[0014] In the figure: 1. pipe string, 2. drilling fluid, 3. controller, 4. controller housing, 5. push cylinder housing, 6. push cylinder, 7. fuse wire, 8. slider, 8a. slider flow channel hole, 8b. slider boss, 8c. slider sealing groove, 9. deflector, 9a. deflector flow channel hole, 9b. deflector flow channel, 10. sealing ring, 11. nozzle, 12. tool housing, 13. high-temperature resistant piston, 14. sealing material, 15. graphite heat insulation layer, 16. propellant, 17. connecting nipple, 18. deflector, 19. pin, 20. steering nozzle, 21. connecting rod, 22. sliding sleeve, 23. recovery rod. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0015] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments:

[0016] As shown Figure 1 in the accompanying drawings, the high-temperature molten cutting tool of the present invention using drilling fluid pressure is mainly composed of a push cylinder, a drainage mechanism, a piston, a charge column, a housing, and a nozzle. The tool is placed in the pipe string 1 and the drilling fluid 2. The controller housing 4 wraps the controller 3. The controller 3 is connected to the fuse 7. The fuse 7 passes through the flow deflector 9 and is connected to the charge column 16 through the high-temperature resistant piston 13. The controller housing 4 is threadedly connected to the push cylinder housing 5. The push cylinder 6 is fixed inside the push cylinder housing 5. The extending push rod of the push cylinder 6 is connected to the slider 8. A sealing ring 10 is installed on the slider 8. The flow deflector 9 is threadedly connected to the push cylinder housing 5. The flow deflector 9 is threadedly connected to the tool housing 11. The flow deflector 9 is provided with two slots. One of the slots is used to pass the fuse 7 and the end is blocked by the sealing ring 12. The inner wall of the tool housing 11 is attached with a graphite heat insulation layer 15. The high-temperature resistant piston 13 is installed at the upper end of the graphite heat insulation layer 15. The high-temperature resistant piston 13 has a hole in the middle. After passing the fuse 7, it is blocked by the sealing material 14, and the charge column 16 is installed inside. The connecting sub 17 is threadedly connected to the tool housing 11. A sealing ring is provided between the connecting sub 17 and the sliding sleeve 22. The pin 19 is installed on the boss of the connecting sub 17. The flow deflector 18 is connected to the steering nozzle 20 and the recovery rod 23 through the connecting rod 21.

[0017] As shown Figure 1 in the Figure 2 accompanying drawings, when the controller 3 ignites the charge column 16 through the fuse, the charge column 16 reacts to generate a large amount of gas and an extremely high temperature. The initially generated gas will flow out along the steering nozzle 20 to push the sliding sleeve 22 downwards, exposing the steering nozzle 20. As the reaction of the agent proceeds, the high-temperature molten metal is pushed by the high-temperature gas and flows downward to the flow deflector 18 for diversion, and then is sprayed from the steering nozzle 20 onto the drill pipe wall to complete the cutting operation.

[0018] As shown Figure 3 in the Figure 5 accompanying drawings Figure 6 and the accompanying drawings, there is a slider sealing groove 8c on the slider 8 that cooperates with the sealing ring 10 for sealing to prevent the drilling fluid from entering. When the charge column 16 is ignited and reacts for 2 seconds, the controller 3 sends a signal to the push cylinder. The push cylinder 6 pushes the slider 8 downward. The slider flow channel hole 8a is aligned with the flow deflector flow channel hole 9a. The drilling fluid flows into the interior of the tool housing 11 through the flow deflector flow channel hole 9a due to the different pressures inside and outside the tool. The pressure of the drilling fluid pushes the high-temperature resistant piston 13 downward, squeezing the internal space of the tool housing 11, generating pressure to better discharge the high-temperature gas generated by the high-temperature molten reaction from the tool, achieving a better cutting effect.

[0019] As shown Figure 4As shown, the high-temperature resistant piston is manufactured by compounding multiple materials, which are metal, graphite, and ceramic. Tungsten alloy ensures the overall strength, ceramic has a low thermal conductivity, and graphite has good heat resistance.

[0020] The specific embodiments described above are used to illustrate this patent rather than limit the scope of this patent. Any equivalent changes and modifications made by those skilled in the art without departing from the concept and principles of this patent fall within the protection scope of this patent system.

Claims

1. A high-temperature melting cutting tool using drilling fluid pressurization, mainly composed of a pushing cylinder, a drainage mechanism, a slider, a piston, an explosive column, a tool housing, and a nozzle, characterized in that: The described tool is placed inside the pipe string (1) and the drilling fluid (2). A controller (3) is installed inside the controller housing (4). The controller housing (4) is threadedly connected to the push cylinder housing (5). The controller is connected to the push cylinder (6) through a signal wire (7). The push cylinder (6) is fixed inside the push cylinder housing (5). The extended push rod of the push cylinder (6) is connected to the slider (8). The flow guide (9) is threadedly connected to the push cylinder housing (5), and the flow guide (9) is threadedly connected to the tool housing (11). A high-temperature resistant piston (13) is installed at the upper end inside the graphite heat insulation layer (15). There is a slider sealing groove (8c) on the slider (8) that cooperates with the sealing ring (10) for sealing to prevent the drilling fluid from entering. After the explosive column (16) is ignited and reacts for 2 seconds, the controller (3) sends a signal to the push cylinder (6). The push cylinder (6) pushes the slider (8) downward. Limited by the slider boss (8b), the slider flow channel hole (8a) is aligned with the flow guide flow channel hole (9a). Due to the different pressures inside and outside the tool, the drilling fluid flows into the inside of the tool housing (11) through the flow guide flow channel hole (9a). The pressure of the drilling fluid pushes the high-temperature resistant piston (13) downward, squeezing the internal space of the tool housing (11), generating pressure to better discharge the high-temperature gas generated by the high-temperature melting reaction from the tool, achieving a better cutting effect.

2. The high-temperature melting cutting tool pressurized by drilling fluid according to claim 1, characterized in that: The high-temperature resistant piston is manufactured by compounding multiple materials, and the materials are tungsten alloy, ceramic, and graphite; the tungsten alloy ensures the overall strength, the ceramic has a low thermal conductivity, and the graphite has good heat resistance.

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