An expandable open hole packer

Abstract

The present application relates to a kind of dilatation bare hole packer, including tubular body, the first passage of fluid flow is defined in the body, and expansion cylinder is arranged on the outer wall of the body, second passage is provided on the body, which communicates the first passage and expansion cylinder.Therein, upper rubber cylinder seat and lower rubber cylinder seat are respectively arranged on the outer wall of the body at the both ends of the expansion cylinder, and the expansion cylinder is connected on the body by the upper rubber cylinder seat and lower rubber cylinder seat.The upper rubber cylinder seat and lower rubber cylinder seat are arranged to be able to slide on the outer wall of the body under the drive of the expansion cylinder when the expansion cylinder is deformed.The dilatation bare hole packer of the present application can effectively improve its own pressure resistance, while improving the reliability of sealing.

Description

Technical Field

[0001] This invention relates to an expandable naked-eye occluder. Background Technology

[0002] Open-hole packers are key tools for interlayer sealing in open-hole staged fracturing. These packers primarily rely on fluid-filled rubber sleeves for annular sealing. Furthermore, during staged fracturing, these packers must withstand pressure from both the lower and upper layers sequentially.

[0003] Existing hydraulic expansion open-hole packers mainly consist of an outer packer, a steel frame, and an inner packer. The steel frame is typically welded to the packer holders at both ends, and the upper or both ends of the packer holders are fixed to the packer mandrel, thus achieving the connection between the packer and the packer mandrel.

[0004] When subjected to unidirectional high pressure, the existing welded structure of the packer sleeve is subjected to extremely high tensile loads. Under this tensile load, fractures are prone to occur near the welded position of the packer sleeve, leading to packer failure. Therefore, existing open-eye packers have low pressure resistance and reliability after packing. Summary of the Invention

[0005] To address the technical problems described above, this invention aims to provide an expandable open-eye packer. The expandable open-eye packer of this invention can effectively improve its own pressure resistance while simultaneously enhancing the reliability of the packer.

[0006] According to the present invention, an expandable naked-eye occluder is provided, comprising a tubular body, wherein a first channel for fluid flow is defined within the body, and an expansion cylinder disposed on the outer wall of the body, wherein a second channel communicating with the first channel and the expansion cylinder is disposed on the body.

[0007] An upper glue cylinder seat and a lower glue cylinder seat are respectively provided on the outer wall of the main body at both ends of the expansion cylinder, and the expansion cylinder is connected to the main body through the upper glue cylinder seat and the lower glue cylinder seat. The upper glue cylinder seat and the lower glue cylinder seat are configured to slide on the outer wall of the main body under the action of the expansion cylinder when the expansion cylinder deforms.

[0008] In a preferred embodiment, annular cavities are respectively provided between the upper and lower glue tube seats and the body, and an opening is provided at one end of the annular cavity near the expansion cylinder.

[0009] The expansion cylinder has connecting parts at both ends that extend into the opening and are fixedly connected to the upper and lower glue cylinder seats, so that the upper and lower glue cylinder seats can slide when the expansion cylinder deforms.

[0010] In a preferred embodiment, a connecting component is provided between the lower glue cartridge seat and the body, which only allows the lower glue cartridge seat to move upward relative to the body.

[0011] A first shear pin and a second shear pin are respectively provided between the upper and lower glue tube seats and the body. The first shear pin is configured to have a shearing force greater than that of the second shear pin.

[0012] In a preferred embodiment, the connecting assembly includes ratchet teeth disposed on the outer wall of the body and a ratchet ring fitted on the ratchet teeth.

[0013] In a preferred embodiment, the expandable naked-eye occluder further includes a control component having a first state of closing the second channel and a second state of keeping the second channel open.

[0014] In a preferred embodiment, the control component includes a piston chamber disposed on the upper side of the glue cylinder seat and a piston disposed within the piston chamber.

[0015] The piston can move within the piston chamber under the action of fluid pressure in the first channel, thereby having an initial first position that cuts off the communication between the expansion cylinder and the first channel and a second position that connects the expansion cylinder and the first channel.

[0016] In a preferred embodiment, a stepped portion is provided on the inner wall of the piston chamber, the stepped portion dividing the piston chamber into a large-diameter section close to the expansion cylinder and a small-diameter section away from the expansion cylinder that can be closed by the piston.

[0017] A through hole communicating with the first channel is provided on the inner wall of the small-diameter section on the upper side of the piston.

[0018] In a preferred embodiment, an elastic element is further provided at the lower end of the piston, and the piston is connected to the side wall of the piston cavity through the elastic element.

[0019] The elastic element is configured to be in a natural, unforced state when the piston is in the first position.

[0020] In a preferred embodiment, a third shear pin is further provided on the piston, the piston is connected to the piston cavity through the third shear pin, and the third shear pin has a shearing force less than that of the second shear pin.

[0021] In a preferred embodiment, the piston chamber has an extension that extends into the annular cavity, a first boss is provided on the inner wall of the upper end of the upper rubber sleeve seat, and a second boss is provided on the outer wall of the lower end of the extension that can abut against the first boss. Attached Figure Description

[0022] The present invention will now be described with reference to the accompanying drawings.

[0023] Figure 1 A schematic diagram of an expandable naked-eye occluder according to an embodiment of the present invention is shown.

[0024] Figure 2 for Figure 1 The diagram shows the expansion cylinder of the expandable naked-eye packer after expansion.

[0025] Figure 3 for Figure 1 The diagram shows an expansion-type naked-eye occluder subjected to pressure from above.

[0026] In this application, all drawings are schematic and are used only to illustrate the principles of the invention, and are not drawn to scale. Detailed Implementation

[0027] The invention will now be described with reference to the accompanying drawings. In this document, the terms "upper end," "upper side," or similar terms refer to the end or side closer to the wellhead, while "lower end," "lower side," or similar terms refer to the end or side farther from the wellhead.

[0028] Figure 1 A schematic diagram of an expandable naked-eye occluder 100 according to an embodiment of the present invention is shown. Figure 1 As shown, the expandable open-hole packer 100 includes a body 10 connected to a downhole drill string (not shown). The body 10 is tubular in shape and defines a fluid flow channel 12 within the body 10, allowing high-pressure fluids such as drilling fluid in the downhole drill string to flow through the body 10 via the channel 12.

[0029] like Figure 1 As shown, an expansion cylinder 20 capable of expansion and deformation is provided on the outer wall of the main body 10. The expansion cylinder 20 can be, for example, a rubber tube. Simultaneously, a second channel 15 is provided on the main body 10, connecting the first channel 12 and the expansion cylinder 20. This allows the high-pressure fluid in the first channel 12 to enter the expansion cylinder 20 through the second channel 15, thereby supporting the expansion cylinder 20 to expand and deform until the expansion cylinder 20 abuts against the inner wall of the well casing, achieving well casing sealing.

[0030] like Figure 1 As shown, an upper glue cylinder seat 30 and a lower glue cylinder seat 40 are respectively provided on the outer wall of the body 10 at both ends of the expansion cylinder 20. The expansion cylinder 20 is connected to the body through the upper glue cylinder seat 30 and the lower glue cylinder seat 40, thereby fixing the expansion cylinder 20.

[0031] In this invention, the upper glue cylinder seat 30 and the lower glue cylinder seat 40 are configured to slide relative to the body 10 on the outer wall of the body 10 under the drive of the expansion cylinder 20 when the expansion cylinder 20 expands and deforms.

[0032] Specifically, annular cavities 32 are respectively provided between the upper glue sleeve seat 30 and the lower glue sleeve seat 40 and the body 10, and an opening 34 is provided at one end of the annular cavity 32 near the expansion cylinder 20. At the same time, connecting parts 35 are respectively provided at both ends of the expansion cylinder 20, extending into the opening 34 and forming a fixed connection with the upper glue sleeve seat 30 and the lower glue sleeve seat 40.

[0033] Therefore, when the expansion cylinder 20 expands, its radial dimension along the body 10 gradually increases, while its axial dimension along the body 10 gradually decreases. As this process proceeds, the connecting portion 35 gradually moves relative to the body 10 toward the expansion cylinder 20, thereby causing the upper glue holder 30 and the lower glue holder 40 to move toward the expansion cylinder 20.

[0034] At the same time, such as Figure 1 As shown, a connecting assembly 50 is provided between the lower glue cartridge seat 40 and the body 10. The connecting assembly 50 includes a ratchet 52 disposed on the outer wall of the body 10 and a ratchet ring 55 sleeved on the ratchet and fixedly connected to the lower glue cartridge seat 40. The ratchet 52 is configured to allow only the ratchet ring 55 to move upward. Thus, the connecting assembly 50 enables the lower glue cartridge seat 40 to move upward relative to the body 10.

[0035] Furthermore, a first shearing pin 36 and a second shearing pin 46 are respectively provided between the upper glue sleeve seat 30 and the lower glue sleeve seat 40 and the body 10. The first shearing pin 36 is configured to have a shearing force greater than that of the second shearing pin 46.

[0036] Figure 2 for Figure 1 A schematic diagram of the expansion cylinder 20 of the expandable naked-eye packer 100 after expansion. (See diagram below.) Figure 2 As shown, when the high-pressure fluid in the first channel 12 enters the expansion cylinder 20 through the second channel 15, the connecting part 35 tends to move closer to the expansion cylinder 20 as the expansion cylinder 20 expands. Since the first shear pin 36 is configured to have a greater shearing force than the second shear pin 46, the second shear pin 46 will be sheared first as the liquid pressure continues to increase.

[0037] like Figure 2As shown, when the second shear pin 46 is sheared, the lower rubber sleeve seat 40 will move upward under the drive of the expansion cylinder 20, which in turn will drive the ratchet ring 55 to move upward relative to the ratchet 52 until the expansion cylinder 20 abuts against the well barrel, thus achieving expansion sealing.

[0038] Since the ratchet ring 55 cannot move downward relative to the ratchet 52, when the expansion cylinder 20 comes into contact with the wellbore, it will remain in an expanded sealing state under the restriction of the ratchet ring 55, thereby achieving continuous sealing of the wellbore.

[0039] In actual operation, when the expansion cylinder 20 is in the expanded and sealed state, it is easily affected by downhole pressure from both the upper and lower sides. When the expansion cylinder 20 is subjected to wellbore pressure from below, the pressure is transmitted to the ratchet ring 55 connected to the lower rubber sleeve seat 40, thereby causing the ratchet ring 55 and the lower rubber sleeve seat 40 to move upward.

[0040] This design allows the lower rubber sleeve seat 40 to push the expansion cylinder 20 to continue expanding and deforming, thereby increasing the force between the expansion cylinder 20 and the inner wall of the wellbore, and thus improving the sealing performance of the expansion cylinder 20 by utilizing this pressure. Furthermore, this design prevents the wellbore pressure from being transmitted to the connection between the lower rubber sleeve seat 40 and the expansion cylinder 20, thus preventing the lower rubber sleeve seat 40 from separating from the expansion cylinder 20 due to high pressure. This significantly improves the high pressure resistance of the expansion-type open-hole packer 100 of the present invention, thereby enhancing the reliability and applicability of the packer 100.

[0041] Figure 3 for Figure 1 This is a schematic diagram showing the expansion-type open-eye occluder 100 subjected to pressure from above. (See diagram for reference.) Figure 3 As shown, when the expansion cylinder 20 of the expandable open-hole packer 100 is subjected to wellbore pressure from above, the upper rubber sleeve seat 30 will tend to move downward under this pressure.

[0042] As the pressure increases, the second shear pin 36 will be sheared off, and then the upper glue cylinder seat 30 will move downward. During this movement, since the ratchet ring 55 cannot move downward relative to the body 10, the axial torque on the upper glue cylinder seat 30 can be transmitted to the ratchet ring 55.

[0043] This design prevents pressure from above the expansion cylinder 20 from acting directly on the connection between the glue-filling sleeve seat 30 and the expansion cylinder 20, thereby preventing the glue-filling sleeve seat 30 and the expansion cylinder 20 from separating due to high pressure and improving the high pressure resistance of the expansion-type naked eye packer 100 of the present invention.

[0044] Similarly, this setting also allows the pressure to push the upper rubber sleeve seat 30 downward, thereby pushing the expansion cylinder 20 to expand further, thus increasing the force between the expansion cylinder 20 and the inner wall of the well, and improving the sealing performance of the expansion cylinder 20.

[0045] like Figure 1 As shown, the expandable naked-eye packer 100 of the present invention also includes a control component 60. The control component 60 has a first state of closing the second channel 15 and a second state of keeping the second channel 15 open, thereby enabling the operator to control the expansion of the expansion cylinder 20 through the control component 60, and thus control the packing operation of the expandable naked-eye packer 100 of the present invention.

[0046] Specifically, such as Figure 1 As shown, the control assembly includes a piston chamber 62 disposed on the upper side of the upper glue cylinder seat 30 and a piston 64 disposed within the piston chamber. The piston 64 is movable within the piston chamber under the action of fluid pressure in the first channel 12, thereby having an initial first position that cuts off the communication between the expansion cylinder 20 and the first channel 12, and a second position that connects the expansion cylinder 20 and the first channel 12.

[0047] like Figure 1 As shown, a stepped portion 65 is provided on the inner wall of the piston chamber 62, which divides the piston chamber 62 into a large-diameter section 66 near the expansion cylinder 20 and a small-diameter section 68 away from the expansion cylinder 20. The large-diameter section 66 has a larger diameter than the small-diameter section 68.

[0048] Meanwhile, a through hole 69 communicating with the first channel 15 is provided on the inner wall of the small-diameter section 68 on the upper side of the piston 64. Thus, when high-pressure fluid passes through the first channel 15, it flows into the small-diameter section 68 on the upper side of the piston 64 through the through hole 69, and then pushes the piston 64 to move closer to the large-diameter section 66 until the piston 64 is completely inside the large-diameter section 66.

[0049] In this invention, the piston 64 is configured to have a diameter adapted to the small-diameter section 68, such that when the piston 64 is in the small-diameter section 68, it can isolate the piston chamber 62, thereby preventing the high-pressure fluid in the first channel 12 from entering the expansion cylinder 20. When the high-pressure fluid flows through the first channel 12, it flows through the through hole 69 into the small-diameter section 68 above the piston 64 and pushes the piston completely into the large-diameter section 66. At this time, since the large-diameter section 66 has a larger diameter than the small-diameter section 68, the piston 64 cannot continue to cut off the connection between the expansion cylinder 20 and the first channel 12, and the expansion cylinder 20 can then expand normally.

[0050] It is easy to understand that the operator can inject high-pressure fluid into the first channel 12 to control the movement of the piston 64, thereby controlling the expansion process of the expansion cylinder 20.

[0051] In a preferred embodiment, an elastic element 70, such as a spring, is further provided at the lower end of the piston 64. The piston 64 can be connected to the side wall of the piston chamber 62 via the elastic element 70. The elastic element is configured to be in a stress-free natural state when the piston 64 is in its initial position within the small-diameter section 68.

[0052] Therefore, when the high-pressure liquid pushes the piston 64 into the large-diameter section 66, the elastic element 70 is compressed. Once the expansion cylinder 20 has fully expanded, as the operator stops injecting high-pressure fluid into the first channel 12, the elastic element 70 returns to its unforced natural state and pushes the piston 64 back to its initial first position, thereby re-severing the connection between the first channel 12 and the expansion cylinder 20, thus re-sealing the expansion cylinder 20 and preventing liquid leakage that could lead to seal failure.

[0053] Meanwhile, a third shear pin 72 is also provided on the piston 64, and the piston 64 is connected to the piston chamber 62 through the third shear pin 72. The third shear pin 72 can fix the piston 64 in the initial first position during the well entry process, thereby preventing the expansion cylinder 20 from connecting to the first channel 12 in advance, which would cause the expansion cylinder 20 to expand and seal prematurely.

[0054] Meanwhile, the third shear pin 72 is configured to have a shearing force less than that of the second shear pin 46. This ensures that during the expansion of the expansion cylinder 20, the second shear pin 46 and the third shear pin 56 are sheared off in advance, thereby causing the upper glue cylinder seat 30 and the lower glue cylinder seat 40 to move in advance.

[0055] like Figure 3 As shown, in a preferred embodiment, an extension 80 extending into the annular cavity 32 is provided on the piston cavity 62. Meanwhile, a first boss 82 is provided on the inner wall of the upper end of the upper rubber sleeve seat 30, and a second boss 84 capable of abutting against the first boss 82 is provided on the outer wall of the lower end of the extension 80.

[0056] With this configuration, when the upper glue cylinder seat 30 moves downward, the upper glue cylinder seat 30 can slide relative to the piston chamber 62. At this time, the first boss 82 and the second boss 84 can abut against and prevent the upper glue cylinder seat 30 from continuing to move downward, thereby limiting the formation of the upper glue cylinder seat 30 moving downward and preventing the upper glue cylinder seat 30 from separating from the piston chamber 62, causing the piston chamber 62 to leak.

[0057] The working process of the expandable naked-eye occluder 100 according to the present invention is briefly described below.

[0058] The expandable open-hole packer 100 of the present invention is used to connect to the downhole drill string and is lowered into the well along with the downhole drill string. When the body 10 reaches the designated downhole position, the third shear pin 72 is cut off by injecting high-pressure fluid into the first channel 12, allowing the piston 64 to move from the initial small-diameter section 68 to the large-diameter section 66, thereby allowing high-pressure fluid to enter the expansion cylinder 20 through the piston chamber 62, causing the expansion cylinder 20 to expand and achieve expansion sealing.

[0059] Once the expansion cylinder 20 has achieved its sealing state, the operator can stop injecting high-pressure fluid. At this point, the piston 64, under the action of the elastic element 70, will re-sever the connection between the expansion cylinder 20 and the first channel 12.

[0060] Subsequently, when the expansion cylinder 20 is subjected to wellbore pressure from below, the pressure is transmitted to the ratchet ring 55 connected to the lower rubber sleeve seat 40, thereby causing the ratchet ring 55 and the lower rubber sleeve seat 40 to move upward.

[0061] This design improves the sealing performance of the expansion cylinder 20 and prevents wellbore pressure from being transmitted to the connection between the lower rubber sleeve seat 40 and the expansion cylinder 20, thus preventing the lower rubber sleeve seat 40 and the expansion cylinder 20 from separating due to high pressure and improving the high pressure resistance of the expansion-type open hole packer 100 of the present invention.

[0062] Similarly, when the expansion cylinder 20 is subjected to wellbore pressure from above, the upper rubber sleeve seat 30 will tend to move downwards under this pressure. As the pressure increases, the second shear pin 36 will be sheared, and then the upper rubber sleeve seat 30 will move downwards. During this movement, since the ratchet ring 55 cannot move downwards relative to the body 10, the axial torque on the upper rubber sleeve seat 30 can be transmitted to the ratchet ring 55.

[0063] This configuration prevents wellbore pressure from being transmitted to the connection between the lower rubber sleeve seat 40 and the expansion cylinder 20, thereby preventing the lower rubber sleeve seat 40 and the expansion cylinder 20 from separating due to high pressure. This also improves the high pressure resistance of the expansion-type open-hole packer 100 of the present invention.

[0064] Finally, it should be noted that the above description is merely a preferred embodiment of the present invention and does not constitute any limitation on the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of the present invention.

Claims

1. An expandable naked-eye occluder (100), comprising: A tubular body (10), wherein a first channel (12) for fluid flow is defined within the body, and, An expansion cylinder (20) is provided on the outer wall of the main body, and a second channel (15) is provided on the main body to connect the first channel and the expansion cylinder. An upper glue tube seat (30) and a lower glue tube seat (40) are respectively provided on the outer wall of the body at both ends of the expansion cylinder. The expansion cylinder is connected to the body through the upper glue tube seat and the lower glue tube seat. An annular cavity (32) is provided between the upper glue tube seat and the lower glue tube seat and the body. An opening (34) is provided at one end of the annular cavity near the expansion cylinder. Connecting parts (35) are provided at both ends of the expansion cylinder, extending into the opening and forming a fixed connection with the upper glue tube seat and the lower glue tube seat, so that the upper glue tube seat and the lower glue tube seat can slide when the expansion cylinder deforms. The upper and lower rubber sleeve seats are configured to slide on the outer wall of the body under the action of the expansion cylinder when the expansion cylinder deforms. Among them, a first shear pin and a second shear pin are respectively provided between the upper and lower glue tube seats and the body. The first shear pin is configured to have a shearing force greater than that of the second shear pin. A connecting component (50) is provided between the lower glue tube seat and the body, which only allows the lower glue tube seat to move upward relative to the body. The connecting component includes a ratchet (52) provided on the outer wall of the body and a ratchet ring (55) sleeved on the ratchet. The lower glue tube seat is allowed to move upward relative to the body through the cooperation of the ratchet and the ratchet ring.

2. The expandable naked-eye occluder according to claim 1, characterized in that, It also includes a control component (60) having a first state that closes the second channel and a second state that keeps the second channel open.

3. The expandable naked-eye occluder according to claim 2, characterized in that, The control assembly includes a piston chamber (62) disposed on the upper side of the upper glue cylinder seat and a piston (64) disposed in the piston chamber. The piston can move within the piston chamber under the action of fluid pressure in the first channel, thereby having an initial first position that cuts off the communication between the expansion cylinder and the first channel and a second position that connects the expansion cylinder and the first channel.

4. The expandable naked-eye occluder according to claim 3, characterized in that, A stepped portion (65) is provided on the inner wall of the piston chamber, which divides the piston chamber into a large-diameter section (66) close to the expansion cylinder and a small-diameter section (68) far from the expansion cylinder that can be closed by the piston. A through hole (69) connecting the first channel is provided on the inner wall of the small-diameter section on the upper side of the piston.

5. The expandable naked-eye occluder according to claim 4, characterized in that, An elastic element (70) is also provided at the lower end of the piston, and the piston is connected to the side wall of the piston cavity through the elastic element. The elastic element is configured to be in a natural, unforced state when the piston is in the first position.

6. The expandable naked-eye occluder according to claim 3 or 4, characterized in that, A third shear pin (72) is also provided on the piston, and the piston is connected to the piston cavity through the third shear pin. The third shear pin has a shearing force that is less than that of the second shear pin.

7. The expandable naked-eye occluder according to claim 3 or 4, characterized in that, The piston chamber has an extension (80) that extends into the annular cavity. A first boss (82) is provided on the inner wall of the upper end of the upper rubber sleeve seat, and a second boss (84) that can abut against the first boss is provided on the outer wall of the lower end of the extension.

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