A Cementing Annular Hydraulic Packing Tool, Production Casing and Its Packing Method

Abstract

The present invention relates to a cementing annulus hydraulic isolation tool, a production casing and a method for isolating the same. The cementing annulus hydraulic isolation tool includes a driving mechanism, a valve rod positioning ring, valve rods, a thrust ring cylinder and a rubber barrel assembly. The valve rod positioning ring can move axially under the drive of the driving mechanism. A plurality of valve rods are connected to the valve rod positioning ring, and the valve rods are parallel to the axis of the valve rod positioning ring. A plurality of valve rod cavities are formed on one end face of the thrust ring cylinder, and the plurality of valve rods are hermetically and slidably arranged in the plurality of valve rod cavities in a one-to-one correspondence; a first annular sealing portion is provided on the inner side wall of the thrust ring cylinder, and an annular sealing cavity is formed by surrounding between the first annular sealing portion, the outer side wall of the production casing and the thrust ring cylinder. The other end of the thrust ring cylinder is coaxially connected to the rubber barrel assembly; a plurality of first through holes are formed on the outer side wall of the thrust ring cylinder, and a plurality of second through holes communicating with the annular sealing cavity are formed on the inner side wall of the thrust ring cylinder. The plurality of first through holes and the plurality of second through holes are all communicated with the plurality of valve rod cavities in a one-to-one correspondence.

Description

Technical Field

[0001] The present invention relates to the field of oil drilling and completion engineering, and particularly relates to a cementing annulus hydraulic isolation tool, a production casing and a sealing method thereof. Background Art

[0002] With the development of the oil and gas industry, the production of oil and gas wells, especially natural gas wells, mostly faces downhole environments with high temperature, high pressure and high corrosive gas content. The phenomenon of abnormal annulus pressure is gradually increasing, which has become an important problem affecting the safe production of oil and gas wells. For many complex well conditions, it is difficult to completely solve the problems of annulus fluid loss and annulus pressure by only improving the cement slurry system and construction technology. Therefore, in order to seek more effective solutions, casing packers have begun to be applied to the treatment of cementing annulus fluid loss. The commonly used casing packers in China mostly adopt hydraulic expansion type external casing packers. For existing cementing hydraulic isolation tools, whether it is an expansion type packer or a compression type packer, the method of pressurizing inside the pipe is commonly used, and the setting force is applied by using the pressure difference between the inside and outside of the casing. Therefore, when setting, it is necessary to open holes on the casing to facilitate the passage of hydraulic fluid. However, the flow channels and drainage holes existing in the casing body will form weak points in the cementing seal, damage the integrity of the pipe string, and form certain potential safety hazards; at the same time, the internal retaining pin structure will cause certain damage to the displacement plug when opening, affecting the normal use of subsequent cementing tools; in addition, the conventional water- and oil-swelling packers have poor pressure-bearing capacity and slow swelling rate, which bring inconvenience to subsequent operation construction. Therefore, it is necessary to invent a cementing annulus hydraulic isolation tool to improve the performance of the packer and solve the problems of annulus fluid loss and annulus pressure under increasingly complex well conditions in China. Summary of the Invention

[0003] The present invention provides a cementing annulus hydraulic isolation tool, a production casing and a sealing method thereof to solve one or several of the technical problems existing in the prior art.

[0004] The technical solution of the present invention to solve the above technical problems is as follows: A cementing annulus hydraulic isolation tool includes a driving mechanism, a valve stem positioning ring, a valve stem, a thrust ring cylinder and a rubber barrel assembly. The valve stem positioning ring is annular and can move axially under the drive of the driving mechanism. Multiple valve stems are connected to the valve stem positioning ring. The valve stems extend along a direction parallel to the axis of the valve stem positioning ring. The thrust ring cylinder is coaxially arranged with the valve stem positioning ring. A plurality of valve stem cavities are opened on one end face of the thrust ring cylinder. Multiple valve stems are hermetically and slidably arranged in the plurality of valve stem cavities in a one-to-one correspondence.

[0005] On the inner side wall of the thrust ring cylinder, there is a first annular sealing portion for sealingly mating with the outer side wall of the production casing. An annular sealing cavity is formed by enclosing between the first annular sealing portion, the outer side wall of the production casing, and the inner side wall of the thrust ring cylinder. The other end of the thrust ring cylinder is coaxially connected to the rubber barrel assembly. A plurality of first through holes are formed on the outer side wall of the thrust ring cylinder, and a plurality of second through holes communicating with the annular sealing cavity are formed on the inner side wall of the thrust ring cylinder. The plurality of first through holes and the plurality of second through holes are respectively and correspondingly communicated with a plurality of valve rod cavities. Among them, the valve rod positioning ring can drive the plurality of valve rods to open or block the second through holes under the drive of the driving mechanism.

[0006] The beneficial effects of the present invention are as follows: The cementing annulus hydraulic packer of the present invention is mainly used for wellbores prone to annulus pressure during production operations. By expanding and sealing the rubber barrel of the packer, the pressure difference between the upper and lower parts is sealed off, thereby preventing the generation of annulus pressure. Aiming at the problem that the existing packer needs to open holes on the production casing for setting, which thus damages the integrity of the pipe string, the driving mechanism drives the valve rod to isolate and communicate the liquid column pressure with the annular sealing cavity, and the setting of the packer is achieved by relying on the pressure difference formed between the liquid column pressure and the annular sealing cavity, with excellent sealing performance, so as to solve the problems of annulus crossflow and annulus pressure in increasingly complex well conditions.

[0007] On the basis of the above technical solutions, the present invention can be further improved as follows.

[0008] Further, the plurality of second through holes are located at positions adjacent to the first annular sealing portion, and the plurality of second through holes are located between the first annular sealing portion and the valve rod positioning ring; the plurality of first through holes are arranged corresponding to the first annular sealing portion.

[0009] The beneficial effect of adopting the above further solution is that by arranging the first through holes and the second through holes in a staggered manner, the second through holes can be opened or blocked by the axial movement of the valve rod.

[0010] Further, one end of the valve rod is fixedly connected to the valve rod positioning ring, and two circles of first sealing rings are provided on the outer side wall of the other end of the valve rod; when the valve rod blocks the second through hole, the second through hole is located between the two circles of first sealing rings, and the other end of the valve rod is arranged at an interval from the first through hole.

[0011] The beneficial effect of adopting the above further solution is that the second through hole can be effectively sealed.

[0012] Further, the first annular sealing portion is a first annular protrusion integrally connected to the inner side wall of the thrust ring cylinder, and a second sealing ring is provided on the free end face of the first annular protrusion.

[0013] The beneficial effect of adopting the above further solution is that the provision of the first annular protrusion can achieve a sealed sliding connection with the thrust ring cylinder.

[0014] Furthermore, the valve stem positioning ring includes a positioning cylinder and a positioning flange, the positioning flange is integrally connected to one axial end of the positioning cylinder, one end of the valve stem is fixedly connected to the positioning flange; the other axial end of the positioning cylinder is connected to the main structure of the driving mechanism through an anti-slip spring.

[0015] The beneficial effect of adopting the above further solution is that the provision of the anti-slip spring is conducive to forming an annular drive cavity, which provides sufficient drive space for driving the valve stem positioning ring.

[0016] Furthermore, the other end of the thrust ring tube is connected to the rubber tube assembly through a backstop mechanism, and the backstop mechanism is annular and coaxially arranged with the thrust ring tube.

[0017] The beneficial effect of adopting the above further solution is that by providing a stop mechanism, it can cooperate with the sleeve body to prevent the rubber sleeve assembly from recovering its deformation.

[0018] Furthermore, it also includes a protective sleeve, an annular driving cavity is reserved between the driving mechanism and the valve stem positioning ring, the protective sleeve sealing sleeve is arranged on the outside of the valve stem positioning ring and the driving mechanism, and the annular driving cavity and one end of the thrust ring tube close to the valve stem positioning ring are covered, and the protective sleeve is fixed on the thrust ring tube.

[0019] The beneficial effect of adopting the above further solution is that the provision of the protective sleeve is conducive to sealing and protecting the annular drive cavity, preventing mud from entering the annular drive cavity and affecting the axial movement of the valve stem positioning ring.

[0020] Furthermore, the driving mechanism includes a power supply mechanism, a pressure wave receiving mechanism and an electromagnet. The pressure wave receiving mechanism is installed between the electromagnet and the power supply mechanism and is used to connect the electromagnet and the power supply mechanism after receiving the pressure wave; the electromagnet cooperates with the valve stem positioning ring and can magnetically attract the valve stem positioning ring for axial movement.

[0021] The beneficial effect of adopting the above further solution is that the valve stem positioning ring can be remotely controlled and driven.

[0022] A production casing includes the above-mentioned cementing annulus hydraulic packoff tool, and also includes a casing body. A second annular seal is provided on the outer side wall of the casing body. The second annular seal is located between the valve stem positioning ring and the first annular seal. The second annular seal is in sealed sliding fit with the inner side wall of the thrust ring cylinder. The second annular seal, the first annular seal, the outer side wall of the casing body, and the inner side wall of the thrust ring cylinder enclose to form the annular seal cavity. One end of the rubber barrel assembly facing away from the thrust ring cylinder is fixed on the outer side wall of the casing body.

[0023] The beneficial effect of the present invention is that the production casing of the present invention is used for a wellbore where an annular pressure phenomenon is likely to occur during production operations. The differential pressure between the upper and lower parts is sealed by the expansion of the rubber barrel of the packoff tool, thereby preventing the generation of the annular pressure phenomenon.

[0024] Furthermore, an annular step is also provided on the outer side wall of the casing body. The first annular seal can be adapted to abut and be limited by the annular step to form the annular seal cavity.

[0025] The thrust ring cylinder is also hermetically connected to the outer side wall of the casing body through a metal seal ring. The metal seal ring is located on the side of the first annular seal facing away from the valve stem positioning ring.

[0026] The beneficial effect of adopting the above further scheme is that the setting of the annular step is beneficial to the formation of the annular seal cavity.

[0027] A packoff method for the production casing includes the following steps:

[0028] Lower the production casing into the wellbore. Use the driving mechanism to drive the valve stem positioning ring to move axially, drive the valve stem to move axially. The valve stem opens the second through hole on the thrust ring cylinder, so that the first through hole, the valve stem cavity, the second through hole, and the annular seal cavity are communicated. Mud enters the annular seal cavity from the first through hole, the valve stem cavity, and the second through hole, and pushes the first annular seal to move axially, and then drives the thrust ring cylinder to move axially in a direction away from the valve stem positioning ring. The thrust ring cylinder squeezes the rubber barrel assembly, so that the rubber barrel assembly is squeezed against the inner side wall of the wellbore to achieve the packoff operation.

[0029] The beneficial effect of the present invention is that the packoff method of the present invention, according to the actual working conditions of the cementing construction, based on the structural design of automatically forming a setting differential pressure between the annular seal cavity and the annular liquid column, solves the defect that a conventional packer needs to open holes in the casing, protects the integrity of the production casing, and at the same time avoids the damage to the displacement rubber plug by the retaining pin structure in the existing packer. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a schematic cross-sectional structure diagram of the cementing annulus hydraulic packoff tool of the present invention in the casing body;

[0031] Figure 2 for Figure 1 The enlarged structural diagram of the middle A part;

[0032] Figure 3 It is a schematic diagram of the axial cross-sectional structure of the thrust ring cylinder of the present invention;

[0033] Figure 4 It is a structural schematic diagram of an end surface of a thrust ring cylinder of the present invention;

[0034] Figure 5 It is a schematic diagram of the main structure of the anti-retraction mechanism of the present invention;

[0035] Figure 6 It is a cross-sectional structural schematic diagram of the anti-retraction mechanism of the present invention;

[0036] Figure 7 for Figure 6 Schematic diagram of the enlarged structure of part B in the middle.

[0037] In the accompanying drawings, the components represented by the reference numerals are listed as follows:

[0038] 1. Power supply mechanism; 2. Pressure wave receiving mechanism; 3. Spacer; 4. Anti-slip spring; 5. Electromagnet; 6. Valve stem positioning ring; 7. Protective sleeve; 8. First screw; 9. Valve stem; 10. Third sealing ring; 11. First sealing ring; 12. Casing body; 13. Second sealing ring; 14. Thrust ring tube; 15. Fourth sealing ring; 16. Fifth sealing ring; 17. Metal sealing ring; 18. Pressure ring; 19. Retraction mechanism; 20. Rubber cylinder assembly; 21. Spacer ring; 22. Support ring; 23. Second screw; 24. Annular drive chamber; 25. Threaded hole; 26. Wellbore; 27. Annular step; 28. First annular protrusion; 29. ​​First through hole; 30. Valve stem chamber; 31. Second through hole; 32. Annular sealing chamber; 33. Second annular protrusion; 34. Inverted tooth. DETAILED DESCRIPTION

[0039] The principles and features of the present invention are described below in conjunction with the accompanying drawings. The examples given are only used to explain the present invention and are not used to limit the scope of the present invention.

[0040] like Figures 1 to 4As shown in the figure, a cementing annulus hydraulic packoff tool in this embodiment includes a driving mechanism, a valve rod positioning ring 6, a valve rod 9, a thrust ring cylinder 14, and a rubber barrel assembly 20. The valve rod positioning ring 6 is annular and can move axially under the drive of the driving mechanism. A plurality of valve rods 9 are connected to the valve rod positioning ring 6. The valve rods 9 are arranged extending in a direction parallel to the axis of the valve rod positioning ring 6. The thrust ring cylinder 14 is coaxially arranged with the valve rod positioning ring 6. A plurality of valve rod cavities are provided on one end face of the thrust ring cylinder 14, and a plurality of valve rods 9 are hermetically and slidably arranged in the plurality of valve rod cavities in a one-to-one correspondence;

[0041] A first annular sealing portion for sealingly cooperating with the outer wall of the production casing is provided on the inner side wall of the thrust ring cylinder 14. An annular sealing cavity is formed by enclosing between the outer wall of the production casing and the inner side wall of the thrust ring cylinder 14. The other end of the thrust ring cylinder 14 is coaxially connected to the rubber barrel assembly; A plurality of first through holes 29 are provided on the outer side wall of the thrust ring cylinder 14, and a plurality of second through holes 31 communicating with the annular sealing cavity are provided on the inner side wall of the thrust ring cylinder 14. The plurality of first through holes 29 and the plurality of second through holes 31 are all communicated with the plurality of valve rod cavities 30 in a one-to-one correspondence; Among them, the valve rod positioning ring 6 can drive the plurality of valve rods 9 to open or block the second through holes 31 under the drive of the driving mechanism.

[0042] Specifically, the number of the valve rod cavities can be set arbitrarily, for example, it can be two, three, four, five, etc.

[0043] Such as Figure 1 and Figure 2 As shown in the figure, a plurality of the second through holes 31 in this embodiment are located at positions adjacent to the first annular sealing portion, and the plurality of second through holes 31 are located between the first annular sealing portion and the valve rod positioning ring 6; The plurality of first through holes 29 are arranged corresponding to the first annular sealing portion. By arranging the first through holes and the second through holes in a staggered manner, the second through holes can be opened or blocked by the axial movement of the valve rod.

[0044] Such as Figure 1 and Figure 2 As shown in the figure, one end of the valve rod 9 in this embodiment is fixedly connected to the valve rod positioning ring 6, and two circles of first sealing rings 11 are provided on the outer side wall of the other end of the valve rod 9; When the valve rod 9 blocks the second through hole 31, the second through hole 31 is located between the two circles of first sealing rings 11, and the other end of the valve rod 9 is spaced from the first through hole 29. The second through hole can be effectively sealed.

[0045] Such as Figures 1 to 4As shown, the first annular sealing portion of this embodiment is a first annular protrusion 28 integrally connected to the inner sidewall of the thrust ring cylinder 14. A second sealing ring 13 is provided on the free end face of the first annular protrusion 28. The setting of the first annular protrusion can achieve a sealed sliding connection with the thrust ring cylinder.

[0046] As Figure 1 and Figure 2 shown, the valve stem positioning ring 6 of this embodiment includes a positioning cylinder and a positioning flange. The positioning flange is integrally connected to one end of the positioning cylinder in the axial direction. One end of the valve stem 9 is fixedly connected to the positioning flange; the other end of the positioning cylinder in the axial direction is connected to the main structure of the driving mechanism through an anti-backlash spring 4. The setting of the anti-backlash spring is beneficial to form an annular driving cavity and provide sufficient driving space for the driving of the valve stem positioning ring.

[0047] As Figures 5 to 7 shown, the other end of the thrust ring cylinder 14 of this embodiment is connected to the rubber cylinder assembly through a backstop mechanism 19. The backstop mechanism 19 is annular and coaxially arranged with the thrust ring cylinder 14. By setting the backstop mechanism, it can cooperate with the casing body to prevent the rubber cylinder assembly from recovering deformation.

[0048] Specifically, as Figures 5 to 7 shown, the backstop mechanism 19 has an unclosed circular ring structure. Multiple rows of reverse teeth 34 arranged along the axial direction of the backstop mechanism 19 are provided on the inner sidewall of the backstop mechanism 19. Anti-backlash teeth matching with the reverse teeth 34 can also be provided on the outer sidewall of the casing body 12. When the thrust ring cylinder 14 moves axially, every time it moves a certain distance, the reverse teeth 34 can be used to cooperate with the anti-backlash teeth to prevent the rubber cylinder assembly 20 from retreating.

[0049] Furthermore, as Figure 1 and Figure 2 shown, a pressure-bearing ring 18 is also provided between the backstop mechanism 19 and the thrust ring cylinder 14. The pressure-bearing ring 18 can be fixedly connected to the backstop mechanism 19 and the thrust ring cylinder 14 respectively, or can be in contact with the backstop mechanism 19 and the thrust ring cylinder 14 respectively.

[0050] As Figure 1 and Figure 2As shown in the figure, the cementing annulus hydraulic packoff tool of this embodiment further includes a protective sleeve 7. There is an annular drive cavity 24 reserved between the drive mechanism and the valve rod positioning ring 6. The protective sleeve 7 is sleeved on the outside of the valve rod positioning ring 6 and the drive mechanism in a sealed manner, and covers the annular drive cavity 24 and one end of the thrust ring cylinder 14 close to the valve rod positioning ring 6. The protective sleeve 7 is fixed on the thrust ring cylinder 14. The protective sleeve 7 can be fixed on the thrust ring cylinder 14 through the first screw 8. Specifically, radial threaded holes 25 can be provided on the outer side wall of the thrust ring cylinder 14, and then the thrust ring cylinder 14 and the protective sleeve 7 are fixedly connected by using the first screw 8. The setting of the protective sleeve is beneficial to block and protect the annular drive cavity, prevent mud from entering the annular drive cavity, and affect the axial movement of the valve rod positioning ring.

[0051] As Figure 1 and Figure 2 shown in the figure, the drive mechanism of this embodiment includes a power supply mechanism 1, a pressure wave receiving mechanism 2 and an electromagnet 5. The pressure wave receiving mechanism 2 is installed between the electromagnet 5 and the power supply mechanism and is used to make the electromagnet 5 conduct with the power supply mechanism after receiving the pressure wave; the electromagnet 5 cooperates with the valve rod positioning ring 6 and can magnetically attract the valve rod positioning ring 6 to move axially. It can realize the remote control drive of the valve rod positioning ring. Specifically, there is also a spacer 3 between the pressure wave receiving mechanism 2 and the electromagnet 5. The electromagnet 5 is an annular electromagnet and can be sleeved on the production casing. The power supply mechanism 1 can be an annular battery, and the pressure wave receiving mechanism 2 is also an annular structure. The pressure wave receiving mechanism 2 can cooperate with the pressure wave generating mechanism at the wellhead to receive the pressure wave with a changing frequency generated by the pressure wave generating mechanism. When the changing frequency of the pressure wave meets the preset requirements, the pressure wave receiving mechanism 2 can connect the annular battery with the electromagnet, make the electromagnet adsorb the valve rod positioning ring, and drive the valve rod to move axially. Among them, both the pressure wave receiving mechanism 2 and the pressure wave generating mechanism are realized by using existing structures.

[0052] Specifically, as Figure 1 shown in the figure, the rubber barrel assembly 20 of this embodiment includes a plurality of rubber barrels, and the number of rubber barrels can be set arbitrarily according to needs. There are spacer rings 21 and support rings 22 between adjacent rubber barrels, and spacer rings 21 and support rings 22 are also provided at the ends of the rubber barrels at the outermost ends. The support ring 22 can be fixedly connected to the pipe wall of the production casing through the second screw 23.

[0053] The cementing annulus hydraulic packer tool of this embodiment is connected to the casing string at the designed position, lowered into the wellbore. After the casing string is lowered to the designed position, the cementing operation is carried out according to the normal cementing operation process. It is mainly used for wellbores prone to annulus pressure during production operations. By expanding and sealing the rubber cylinder of the packer tool to seal the pressure difference between the upper and lower parts, the generation of annulus pressure is prevented. Aiming at the problem that the existing packer needs to open holes in the production casing for setting, thus damaging the integrity of the pipe string, the valve stem is driven by the driving mechanism to isolate and connect the liquid column pressure and the annular sealing cavity, and the setting of the packer tool is realized by relying on the pressure difference formed between the liquid column pressure and the annular sealing cavity. The sealing performance is excellent to solve the annulus crossflow and annulus pressure problems under increasingly complex well conditions.

[0054] As Figure 1 and Figure 2 shown, a production casing of this embodiment includes the above-mentioned cementing annulus hydraulic packer tool, and also includes a casing body 12. A second annular sealing portion is provided on the outer side wall of the casing body 12. The second annular sealing portion is located between the valve stem positioning ring 6 and the first annular sealing portion. The second annular sealing portion is in sealing sliding fit with the inner side wall of the thrust ring cylinder 14. The second annular sealing portion, the first annular sealing portion, the outer side wall of the casing body 12 and the inner side wall of the thrust ring cylinder 14 enclose to form the annular sealing cavity 32; one end of the rubber cylinder assembly away from the thrust ring cylinder is fixed on the outer side wall of the casing body.

[0055] Among them, the second annular sealing portion is a second annular protrusion 33. A third sealing ring 10 is provided at the free end of the second annular protrusion 33. The second annular protrusion 33 can be in sealing sliding fit with the inner side wall of the thrust ring cylinder 14 through the third sealing ring 10.

[0056] As Figure 1 and Figure 2 shown, an annular step 27 is further provided on the outer side wall of the casing body 12 of this embodiment. The first annular sealing portion can be adapted to abut and limit with the annular step 27 to form the annular sealing cavity 32; the thrust ring cylinder 14 is also hermetically connected to the outer side wall of the casing body 12 through a metal sealing ring 17. The metal sealing ring 17 is located on the side of the first annular sealing portion away from the valve stem positioning ring 6. The setting of the annular step is beneficial to the formation of the annular sealing cavity. The metal sealing ring 17 can be hermetically connected to the outer side wall of the casing body 12 and the inner side wall of the thrust ring cylinder 14 through a fourth sealing ring 15 and a fifth sealing ring 16 respectively.

[0057] The production casing of this embodiment is used for wellbores prone to annulus pressure during production operations. By expanding and sealing the rubber cylinder of the packer tool to seal the pressure difference between the upper and lower parts, the generation of annulus pressure is prevented.

[0058] This embodiment also provides a method for isolating a production casing, including the following steps:

[0059] Lower the production casing into the wellbore 26, use the driving mechanism to drive the valve stem positioning ring 6 to move axially, drive the valve stem 9 to move axially, the valve stem 9 opens the second through hole 31 on the thrust ring cylinder 14, so that the first through hole 29, the valve stem cavity, the second through hole 31 and the annular sealing cavity 32 are communicated, the mud enters the annular sealing cavity 32 from the first through hole 29, the valve stem cavity and the second through hole 31, and pushes the first annular sealing part to move axially, and then drives the thrust ring cylinder 14 to move axially in the direction away from the valve stem positioning ring 6, the thrust ring cylinder 14 squeezes the rubber barrel assembly 20, so that the rubber barrel assembly 20 is squeezed on the inner side wall of the wellbore 26 to realize the isolation operation.

[0060] The isolation method of this embodiment, according to the actual working conditions of the cementing construction, based on the structural design of automatically forming a setting differential pressure between the annular sealing cavity and the annulus liquid column, solves the defect that the conventional packer needs to open holes in the casing, protects the integrity of the production casing, and at the same time avoids the damage to the displacement plug by the retaining pin structure in the existing packer.

[0061] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention.

[0062] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one of such features. In the description of the present invention, "a plurality" means at least two, such as two, three, etc., unless otherwise specifically defined.

[0063] In the present invention, unless otherwise clearly defined or limited, terms such as "installed", "connected", "coupled", "fixed", etc. shall be construed in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the internal communication of two components or the interaction relationship between two components, unless otherwise clearly defined. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0064] In the present invention, unless otherwise clearly defined or limited, the first feature being "on" or "under" the second feature may be that the first and second features are in direct contact, or the first and second features are indirectly in contact through an intermediate medium. Moreover, the first feature being "above", "over" and "on top of" the second feature may be that the first feature is directly above or obliquely above the second feature, or merely indicates that the first feature has a higher horizontal height than the second feature. The first feature being "under", "beneath" and "underneath" the second feature may be that the first feature is directly below or obliquely below the second feature, or merely indicates that the first feature has a lower horizontal height than the second feature.

[0065] In the description of this specification, the description with reference to terms such as "one embodiment", "some embodiments", "example", "specific example", or "some examples", etc. means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in a suitable manner in any one or more embodiments or examples. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0066] Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those of ordinary skill in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present invention.

Claims

1. A cementing annulus hydraulic packoff tool, characterized in that, it includes a driving mechanism, a valve rod positioning ring, valve rods, a thrust ring cylinder and a rubber barrel assembly. The valve rod positioning ring is annular and can axially move under the drive of the driving mechanism. Multiple valve rods are connected to the valve rod positioning ring. The valve rods are arranged extending in a direction parallel to the axis of the valve rod positioning ring. The thrust ring cylinder is coaxially arranged with the valve rod positioning ring. Multiple valve rod cavities are formed on one end face of the thrust ring cylinder. Multiple valve rods are hermetically and slidably arranged in the multiple valve rod cavities one by one; a first annular sealing portion for sealingly cooperating with the outer wall of the production casing is provided on the inner side wall of the thrust ring cylinder. An annular sealing cavity is formed by enclosing between the first annular sealing portion, the outer wall of the production casing and the inner side wall of the thrust ring cylinder. The other end of the thrust ring cylinder is coaxially connected to the rubber barrel assembly. Multiple first through holes are formed on the outer side wall of the thrust ring cylinder. Multiple second through holes communicating with the annular sealing cavity are formed on the inner side wall of the thrust ring cylinder. The multiple first through holes and the multiple second through holes are all communicated with the multiple valve rod cavities one by one; wherein, the valve rod positioning ring can drive the multiple valve rods to open or block the second through holes under the drive of the driving mechanism; the multiple second through holes are located at positions adjacent to the first annular sealing portion, and the multiple second through holes are located between the first annular sealing portion and the valve rod positioning ring; the multiple first through holes are arranged corresponding to the first annular sealing portion; one end of the valve rod is fixedly connected to the valve rod positioning ring. Two circles of first sealing rings are provided on the outer side wall of the other end of the valve rod; when the valve rod blocks the second through hole, the second through hole is located between the two circles of first sealing rings, and the other end of the valve rod is arranged at an interval from the first through hole; the first annular sealing portion is a first annular protrusion integrally connected to the inner side wall of the thrust ring cylinder. A second sealing ring is provided on the free end face of the first annular protrusion; the valve rod positioning ring includes a positioning cylinder and a positioning flange. The positioning flange is integrally connected to one end of the positioning cylinder in the axial direction. One end of the valve rod is fixedly connected to the positioning flange; the other end of the positioning cylinder in the axial direction is connected to the main structure of the driving mechanism through an anti-displacement spring; the driving mechanism includes a power supply mechanism, a pressure wave receiving mechanism and an electromagnet. The pressure wave receiving mechanism is installed between the electromagnet and the power supply mechanism and is used to make the electromagnet and the power supply mechanism conduct after receiving the pressure wave; the electromagnet cooperates with the valve rod positioning ring and can magnetically attract the valve rod positioning ring to axially move.

2. The cementing annulus hydraulic packoff tool according to claim 1, characterized in that, the other end of the thrust ring cylinder is connected to the rubber barrel assembly through an anti-retreat mechanism. The anti-retreat mechanism is annular and coaxially arranged with the thrust ring cylinder.

3. The cementing annulus hydraulic packoff tool according to claim 1, characterized in that, It further includes a protective sleeve. An annular driving cavity is reserved between the driving mechanism and the valve stem positioning ring. The protective sleeve is hermetically sleeved on the outer sides of the valve stem positioning ring and the driving mechanism, and covers the annular driving cavity and one end of the thrust ring cylinder close to the valve stem positioning ring. The protective sleeve is fixed on the thrust ring cylinder.

4. A production casing, characterized in that it includes the cementing annulus hydraulic packoff tool according to any one of claims 1 to 3, and further includes a casing body. A second annular sealing portion is provided on the outer side wall of the casing body. The second annular sealing portion is located between the valve stem positioning ring and the first annular sealing portion. The second annular sealing portion is in sealed sliding fit with the inner side wall of the thrust ring cylinder. The second annular sealing portion, the first annular sealing portion, the outer side wall of the casing body, and the inner side wall of the thrust ring cylinder enclose to form the annular sealing cavity; One end of the rubber barrel assembly away from the thrust ring cylinder is fixed on the outer side wall of the casing body.

5. The production casing according to claim 4, characterized in that an annular step is further provided on the outer side wall of the casing body. The first annular sealing portion can be adapted to abut and be limited by the annular step to form the annular sealing cavity; the thrust ring cylinder is further hermetically connected to the outer side wall of the casing body through a metal sealing ring. The metal sealing ring is located on the side of the first annular sealing portion away from the valve stem positioning ring.

6. A method for packing off the production casing according to claim 4 or 5, characterized in that it includes the following steps: Lower the production casing into the wellbore. Use the driving mechanism to drive the valve stem positioning ring to move axially, drive the valve stem to move axially. The valve stem opens the second through hole on the thrust ring cylinder, so that the first through hole, the valve stem cavity, the second through hole, and the annular sealing cavity are communicated. Mud enters the annular sealing cavity from the first through hole, the valve stem cavity, and the second through hole, and pushes the first annular sealing portion to move axially, thereby driving the thrust ring cylinder to move axially in a direction away from the valve stem positioning ring. The thrust ring cylinder squeezes the rubber barrel assembly, so that the rubber barrel assembly is squeezed against the inner side wall of the wellbore to realize the packing off operation.

Images