Pressure-controlled underground temporary closing valve and using method thereof

Abstract

The invention discloses a pressure-controlled underground temporary closing valve and a using method thereof. The pressure-controlled underground temporary closing valve comprises a fixed sealing part and a constant pressure valve part, and the upper end of the constant pressure valve part is connected with the lower end of the fixed sealing part; the constant pressure valve part comprises a constant pressure valve body and a constant pressure valve core; a downward valve seat is arranged in the constant-pressure valve body, and the constant-pressure valve element is arranged in the valve seat and cannot move upwards. The operation principle is simple in field actual use, temporary plugging of a production layer is reliable, non-well-killing shaft operation and rapid production recovery can be achieved, the operation safety coefficient is increased, well killing, drilling and sweeping procedures and pollution of slurry plugging slurry to the production layer are reduced, the slurry and well repairing cost is reduced, and the operation time efficiency is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of oil and gas well operation, in particular to a pressure-controlled downhole temporary closing valve and a use method thereof. Background Art

[0002] Currently, more and more types of downhole temporary sealing operations are required during oil and gas well testing. Traditional temporary sealing methods mainly involve cement plugs and drillable bridge plugs to temporarily seal the formation, and then use drilling and sweeping to remove the blockage. This method has a long operation cycle, requires well killing and even plugging, and is difficult to remove after plugging, which seriously damages the oil and gas formation. If soluble bridge plugs are used for sealing, the dissolution rate is affected by factors such as high temperature and brine, making it impossible to achieve stable and reliable sealing, and posing a significant well control risk.

[0003] Publication (Announcement) No. CN217976113U discloses a temporary well sealing string, comprising an oil tubing string, a tubing plug disposed at the lower portion of the tubing string, a hydraulic bypass valve disposed at the lower end of the tubing string, and a mechanical packer disposed at the lower end of the tubing string. When the tubing string is depressed, the hydraulic bypass valve closes, setting the mechanical packer. When the tubing string is pulled upward, the hydraulic bypass valve opens, releasing the mechanical packer. This utility model is simple to operate and overcomes the time and cost associated with traditional temporary well sealing operations.

[0004] This prior art has the technical problems of complex structure and easy failure in complex underground environment.

[0005] Publication (Announcement) No.: CN113982523A discloses a well repair device capable of temporarily sealing and killing a well. The well repair device is composed of a well repair device body, wherein the well repair device includes a tubing string for temporarily sealing, killing and repairing a well. The tubing string is provided with a hydraulically releasable well killing tieback tieback sealing cylinder, a well killing float shoe, a plug valve, a well killing device seating mechanism, a well killing device and a mechanically released well killing tieback in sequence from bottom to top; the tieback sealing cylinder, the plug valve, the well killing float shoe and the well killing device seating mechanism are connected by API casing threads; the well killing device and the well killing device seating mechanism are connected by left-handed special threads; the invention can quickly and efficiently achieve connection with the oil well casing, and can also achieve high-quality recovery of the device.

[0006] This prior art has the technical problems of complex structure and easy failure in complex underground environment.

[0007] Publication (Announcement) No. CN217001783U discloses a snubbing operation device. A track tube is installed within a spring tube, and a track is formed on the inner wall of the spring tube. A rotational positioning track is formed on the outer wall of the track tube. The rotational positioning track comprises several sets of reset tracks, pressure relief tracks, and a reversing groove. A track pin is positioned within the rotational positioning track. When the track tube is pressed downward or pressure is released upward, it cyclically slides along the lower end of the reset track, the upper end of the reversing groove, and the lower end of the pressure relief track to guide the track tube to open and close the valve flap. This utility model achieves the well-killing function by controlling the opening and closing of the valve flap when the track tube is pressed downward by the relative motion of the track pin within the rotational positioning track of the track tube.

[0008] This prior art is prone to technical problems such as track blockage and structural failure in complex underground environments.

[0009] In short, the technical solutions, technical problems to be solved and beneficial effects produced by the above-mentioned disclosed technologies are all different from the present invention. Regarding more technical features, technical problems to be solved and beneficial effects of the present invention, the above-mentioned disclosed technical documents do not provide any technical inspiration. Summary of the Invention

[0010] To address the aforementioned shortcomings of the prior art, the present invention aims to provide a pressure-controlled downhole temporary shutoff valve and its use method, addressing the need for temporary pressure-sealing of the production layer during oil and gas testing operations. This valve achieves pressure control of the production layer, allows for snubbing of the wellbore, and enables efficient resumption of production. This increases operational safety, reduces the need for snubbing and sweeping operations, and reduces contamination to the production layer, lowering mud and workover costs and improving operational efficiency.

[0011] In order to achieve the above object, the present invention adopts the following technical solutions:

[0012] The pressure-controlled downhole temporary closing valve includes a fixed sealing part and a constant pressure valve part, wherein the upper end of the constant pressure valve part is connected to the lower end of the fixed sealing part; the constant pressure valve part includes a constant pressure valve body and a constant pressure valve core; a downward-facing valve seat is provided in the constant pressure valve body, and the constant pressure valve core is arranged in the valve seat and cannot move upward.

[0013] Furthermore, the constant pressure valve core and the constant pressure valve body are connected via a first shear pin.

[0014] Furthermore, a first sealing ring is provided on the side wall of the constant pressure valve core, and the constant pressure valve body is made of fiber composite material and aluminum alloy material.

[0015] Furthermore, the fixed sealing part includes a central tube, a retaining ring is provided on the outer wall of the lower end of the central tube, and the retaining ring is sequentially mounted with a lower slip, a lower cone, a rubber cylinder assembly, an upper cone, and an upper slip;

[0016] Specifically, the lower end of the central tube is connected to the upper end of the constant pressure valve body using reverse thread.

[0017] Furthermore, the rubber cylinder assembly includes an upper pressure ring, a rubber cylinder, and a lower pressure ring, wherein the upper pressure ring is between the rubber cylinder and the upper cone, and the lower pressure ring is between the rubber cylinder and the lower cone;

[0018] A second sealing ring is provided between the lower end of the central tube and the upper end of the constant pressure valve body.

[0019] Furthermore, a setting power part is provided, which includes a thrust sleeve, a pull rod, a push cylinder, and a hydraulic setting tool;

[0020] Specifically, the lower end of the push cylinder is connected to the upper end of the thrust sleeve, and the upper end is in contact with the hydraulic setting tool;

[0021] Specifically, the lower end of the thrust sleeve is inserted into the upper end of the center tube, the lower end of the thrust sleeve is in contact with the upper end of the upper slip, and a locking ring is provided between the thrust sleeve and the center tube;

[0022] Specifically, the locking ring is connected to the upper end of the central tube to prevent the thrust sleeve from moving upward;

[0023] Specifically, the pull rod is connected to the hydraulic setting tool, and the lower end of the pull rod is connected to the central pipe and the locking ring using a second shear nail.

[0024] Furthermore, a circulation hole is provided on the side wall of the push cylinder.

[0025] In order to achieve the above object, the present invention adopts the following technical solutions:

[0026] The method for using the pressure-controlled downhole temporary closing valve includes the following steps:

[0027] S1. Run the pressure-controlled temporary closing valve, using coiled tubing under pressure without killing the well, or using tubing after killing the well;

[0028] S2. Lower the well to the designed depth and apply pressure to the hydraulic setting tool to open the upper and lower slips and engage the casing. This causes the rubber sleeve assembly to expand and fit the casing to achieve a seal. Continue applying pressure to shear the second shear pin, disengaging the tie rod from the center pipe, and remove the hydraulic setting tool.

[0029] S3. At this time, the constant pressure valve core blocks the formation pressure from flowing upward. Clean water or annular protection fluid is replaced in the upper wellbore according to the design, and a wellbore snubbing operation is implemented. After the production string group is lowered and the gas tree is installed, the constant pressure valve core is knocked down from the blocking seat by applying pressure in the well, the middle channel is restored, and production is resumed.

[0030] S4. When the tubing needs to be pulled out, lower the tubing, release the lower slip, rubber sleeve assembly, and upper slip in sequence, rotate the tubing in the direction of unfastening the reverse thread to release the connection between the constant pressure valve body and the center pipe, pull out the tubing, and remove the remaining part by drilling and sweeping.

[0031] Furthermore, step S2 is to go down to the designed well depth, pressurize the hydraulic setting tool, transmit the pressure to the push cylinder, and the push cylinder squeezes the thrust sleeve. The lower cone, the rubber cylinder assembly, the upper cone, and the upper slip move downward together, so that the lower slip opens and bites the casing. The rubber cylinder assembly is forced to expand and fits the casing to achieve sealing. The upper slip is pushed out by the upper cone to open and bite the casing. When the setting force reaches 12-14T, the second shear pin is cut off, the pull rod is separated from the center pipe, and the hydraulic setting tool is extracted from the upper part. The release pressure is controlled by controlling the number and quality of the second shear pins.

[0032] Compared with the prior art, the present invention has the following beneficial effects:

[0033] When actually used on site, the operating principle is simple, the temporary plugging of the production layer is reliable, and it can achieve wellbore operation without well killing and rapid resumption of production, which increases the safety factor of the operation, reduces the pollution of the production layer to the well killing, drilling and sweeping processes and mud plugging slurry, reduces the mud and well repair costs, and improves the operation time efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 This is a schematic structural diagram of the pressure-controlled downhole temporary closing valve of the present invention;

[0035] In the figure: 1. Constant pressure valve part; 11. Constant pressure valve body; 12. First shear pin; 13. First sealing ring; 14. Constant pressure valve core; 15. Second sealing ring; 2. Fixed sealing part; 21. Lower slip; 22. Lower cone; 23. Center pipe; 24. Cylinder assembly; 25. Upper cone; 26. Upper slip; 3. Setting power part; 31. Second shear pin; 32. Locking ring; 33. Thrust sleeve; 34. Pull rod; 35. Push cylinder; 36. Hydraulic setting tool. DETAILED DESCRIPTION

[0036] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0037] Example 1:

[0038] See also Figure 1 The pressure-controlled downhole temporary closing valve provided by the present invention includes a constant pressure valve part 1, a fixed sealing part 2, and a setting power part 3 which are sequentially connected from bottom to top.

[0039] The constant-pressure valve portion 1 includes a constant-pressure valve body 11 and a constant-pressure valve core 14. A downward-facing valve seat is provided within the constant-pressure valve body 11, and the constant-pressure valve core 14 is positioned within the valve seat and cannot move upward. The constant-pressure valve core 14 is connected to the constant-pressure valve body 11 via a first shear pin 12, enhancing the pressure that the constant-pressure valve core 14 can withstand. A first sealing ring 13 is provided on the sidewall of the constant-pressure valve core 14 to prevent liquid from passing through the gap between the constant-pressure valve body 11 and the constant-pressure valve core 14. The constant-pressure valve body 11 is made of fiber composite material and aluminum alloy, both of which have excellent drilling performance. Flat-bottomed grinding shoes can be used for drilling and removal according to site needs.

[0040] The fixed sealing part 2 includes a center tube 23, and a retaining ring is provided on the outer wall of the lower end of the center tube 23. The lower slip 21, the lower cone 22, the rubber cylinder assembly 24, the upper cone 25, and the upper slip 26 are sequentially mounted on the retaining ring; the rubber cylinder assembly 24 includes an upper pressure ring, a rubber cylinder, and a lower pressure ring. The upper pressure ring is between the rubber cylinder and the upper cone 25, and the lower pressure ring is between the rubber cylinder and the lower cone 22; the lower end of the center tube 23 is connected to the upper end of the constant pressure valve body 11 using a reverse thread, and a second sealing ring 15 is provided between the lower end of the center tube 23 and the upper end of the constant pressure valve body 11.

[0041] The sealing power part 3 includes a thrust sleeve 33, a pull rod 34, a push cylinder 35, and a hydraulic sealing tool 36; the lower end of the push cylinder 35 is connected to the upper end of the thrust sleeve 33, and the upper end is in contact with the hydraulic sealing tool 36. The thrust sleeve 33 is inserted into the upper end of the center pipe 23, and the lower end of the thrust sleeve 33 is in contact with the upper end of the upper slip 26. A locking ring 32 is arranged between the thrust sleeve 33 and the center pipe 23. The locking ring 32 is connected to the upper end of the center pipe to prevent the thrust sleeve 33 from moving upward. The pull rod 34 is connected to the hydraulic sealing tool 36, and the lower end of the pull rod is connected to the center pipe 23 and the locking ring 32 using a second shear nail 31.

[0042] The side wall of the push cylinder 35 is provided with a circulation hole.

[0043] It should be noted that the hydraulic setting tool 36 is a prior art, and its function is to push the push cylinder 35 to move downward, which is clear to those skilled in the art.

[0044] Example 2:

[0045] This embodiment provides a method for using a pressure-controlled downhole temporary closing valve:

[0046] S1. Run the pressure-controlled temporary closing valve, using coiled tubing under pressure without killing the well, or using tubing after killing the well;

[0047] S2. Go down to the designed well depth and pressurize the hydraulic setting tool 36. The pressure is transmitted to the push cylinder 35, which squeezes the thrust sleeve 33. The lower cone 22, the rubber cylinder assembly 24, the upper cone 25, and the upper slips 26 move downward together, causing the lower slips 21 to open and bite the casing. The rubber cylinder assembly is forced to expand and fit the casing to achieve a seal. The upper slips 26 are pushed out by the upper cone 25 to open and bite the casing. When the setting force reaches 12-14T, the second shear pin 31 is sheared, the pull rod 34 is separated from the central pipe 23, and the hydraulic setting tool 36 is extracted from the upper part. The release pressure is controlled by controlling the number and quality of the second shear pins 31.

[0048] At this point, the constant-pressure valve core 14 blocks the upward pressure of the formation pressure. Clean water or annular protection fluid can be replaced in the upper wellbore according to the design to implement a snubbing operation. After the production string is lowered and the Christmas tree is installed, the constant-pressure valve core 14 is knocked down from the blocking seat by applying in-well pressure, restoring the intermediate channel and resuming production.

[0049] S4. When the pipe string needs to be pulled out, lower the pipe string, release the lower slip 21, the rubber sleeve assembly 24, and the upper slip 26 in sequence, rotate the pipe string in the direction of unfastening the reverse thread, and release the connection between the constant pressure valve body 11 and the center pipe 23. Pull out the pipe string, and the remaining part can be removed as a whole by drilling and sweeping.

[0050] All components not discussed in detail in this application and the connection methods of the components in this application are well-known technologies in the technical field and can be directly applied without further explanation.

[0051] In the present invention, the term "plurality" refers to two or more, unless otherwise specified. Terms such as "installed," "connected," "connected," and "fixed" should be interpreted broadly. For example, "connected" can mean fixed, removable, or integral; and "connected" can mean directly or indirectly through an intermediary. Those skilled in the art will understand the specific meanings of these terms in the present invention based on specific circumstances.

[0052] In the description of the present invention, it should be understood that the directions or positional relationships indicated by terms such as "up", "down", "left", "right", "front" and "back" are based on the directions or positional relationships shown in the accompanying 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 unit referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they should not be understood as limiting the present invention.

[0053] Throughout this specification, terms such as "one embodiment," "some embodiments," and "specific embodiments" mean that the specific features, structures, materials, or characteristics described in conjunction with that embodiment or example are included in at least one embodiment or example of the present invention. In this specification, schematic representations of these terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0054] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of protection of the present invention.

Claims

1. A pressure-controlled downhole temporary closing valve, comprising a fixed sealing portion, characterized in that: It also includes a constant pressure valve part, the upper end of which is connected to the lower end of the fixed sealing part; the constant pressure valve part includes a constant pressure valve body and a constant pressure valve core; The constant pressure valve body is provided with a downward valve seat, and the constant pressure valve core is arranged in the valve seat and cannot move upward.

2. The pressure-controlled downhole temporary closing valve according to claim 1, characterized in that: The constant pressure valve core and the constant pressure valve body are further connected via a first shear pin.

3. The pressure-controlled downhole temporary closing valve according to claim 1, characterized in that: The side wall of the constant pressure valve core is provided with a first sealing ring, and the constant pressure valve body is made of fiber composite material and aluminum alloy material.

4. The pressure-controlled downhole temporary closing valve according to claim 1, characterized in that: The fixed sealing part includes a central tube, a retaining ring is provided on the outer wall of the lower end of the central tube, and the retaining ring is sequentially mounted with a lower slip, a lower cone, a rubber cylinder assembly, an upper cone, and an upper slip; The lower end of the central tube is connected to the upper end of the constant pressure valve body by using reverse thread.

5. The pressure-controlled downhole temporary closing valve according to claim 4, characterized in that: The rubber cylinder assembly includes an upper pressure ring, a rubber cylinder, and a lower pressure ring. The upper pressure ring is between the rubber cylinder and the upper cone, and the lower pressure ring is between the rubber cylinder and the lower cone. A second sealing ring is provided between the lower end of the central tube and the upper end of the constant pressure valve body.

6. The pressure-controlled downhole temporary closing valve according to claim 4, characterized in that: A setting power part is also provided, which includes a thrust sleeve, a pull rod, a push cylinder, and a hydraulic setting tool; The lower end of the push cylinder is connected to the upper end of the thrust sleeve, and the upper end is in contact with the hydraulic setting tool; The lower end of the thrust sleeve is inserted into the upper end of the center tube, the lower end of the thrust sleeve contacts the upper end of the upper slip, and a locking ring is provided between the thrust sleeve and the center tube; The locking ring is connected to the upper end of the center tube to prevent the thrust sleeve from moving upward; The pull rod is connected to the hydraulic setting tool, and the lower end of the pull rod is connected to the central pipe and the locking ring using a second shear nail.

7. The pressure-controlled downhole temporary closing valve according to claim 6, characterized in that: The side wall of the push cylinder is provided with a circulation hole.

8. The method for using the pressure-controlled downhole temporary closing valve is characterized in that: The following steps are included: S1. Run the pressure-controlled temporary closing valve, using coiled tubing under pressure without killing the well, or using tubing after killing the well; S2. Lower the well to the designed depth and apply pressure to the hydraulic setting tool to open the upper and lower slips and engage the casing. This causes the rubber sleeve assembly to expand and fit the casing to achieve a seal. Continue applying pressure to shear the second shear pin, disengaging the tie rod from the center pipe, and remove the hydraulic setting tool. S3. At this time, the constant pressure valve core blocks the formation pressure from flowing upward. Clean water or annular protection fluid is replaced in the upper wellbore according to the design, and a wellbore snubbing operation is implemented. After the production string group is lowered and the gas tree is installed, the constant pressure valve core is knocked down from the blocking seat by applying pressure in the well, the middle channel is restored, and production is resumed.

9. The method for using the pressure-controlled downhole temporary closing valve according to claim 8, characterized in that: The following steps are also included: S4. When the tubing needs to be pulled out, lower the tubing, release the lower slip, rubber sleeve assembly, and upper slip in sequence, rotate the tubing in the direction of unfastening the reverse thread to release the connection between the constant pressure valve body and the center pipe, pull out the tubing, and remove the remaining part by drilling and sweeping.

10. The method for using the pressure-controlled downhole temporary closing valve according to claim 8, characterized in that: Step S2 is: Go down to the designed well depth, pressurize the hydraulic setting tool, and the pressure is transmitted to the push cylinder. The push cylinder squeezes the thrust sleeve, and the lower cone, rubber cylinder assembly, upper cone, and upper slips move downward together, so that the lower slips open and bite the casing. The rubber cylinder assembly is forced to expand and fit the casing to achieve sealing. The upper slips are pushed out by the upper cone to open and bite the casing. When the setting force reaches 12-14T, the second shear pin is cut off, the pull rod is separated from the center pipe, and the hydraulic setting tool is extracted from the upper part. The release pressure is controlled by controlling the number and quality of the second shear pins.

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