Thickened oil thermal production well top water channeling and casing damage prevention and treatment system and treatment method

Abstract

The invention discloses a thickened oil thermal production well top water channeling and casing damage prevention and treatment system and treatment method. The system comprises a water layer plugging tool, a casing tool string and an oil pipe tool string. The water layer plugging tool is used for conducting naked eye pretreatment on a water layer in the well drilling stage so as to plug the water layer. The casing tool string is used for performing deformation prevention and treatment on a casing and reinforcing a well cementation cement sheath in a well completion stage; the oil pipe tool string is used for blocking the interlayer after the top water moves up and down in the production stage. The system can plug or protect a water layer, a cement sheath and the like at different stages, so that the problems of casing damage and top water channeling can be effectively prevented and treated, the production cycle of an oil well is prolonged, and normal production of an oil field is guaranteed.

Description

Technical Field

[0001] The present invention relates to the technical field of oil drilling and production engineering, and particularly relates to a system and a treatment method for preventing and controlling the upward water channeling at the top of a heavy oil thermal recovery well and casing damage. Background Art

[0002] In some existing oilfields, the heavy oil blocks are mainly developed by steam stimulation. At present, they have entered the middle and late stages of development. Due to the influence of multiple rounds of high-temperature steam stimulation, the casing expands and elongates, which may cause various forms of damage to the casing, such as: casing fracture, joint leakage, thread slippage, and upward movement of the wellhead casing. In the initial stage of the development of such heavy oil reservoirs, due to the lack of matching technical measures, the casing of the thermal recovery well is severely damaged after several rounds of steam injection. In some cases, the upward movement of the wellhead casing is as high as 2m, seriously affecting the normal production of the oil well. In addition, the high-temperature and high-pressure steam generates thermal expansion elastic energy in the reservoir rock skeleton, the cement sheath, and the production casing, and then generates a huge periodic alternating stress mutation, causing the cement sheath to loosen or crack, resulting in channeling outside the oil well pipe, causing upward water channeling at the top, and the oil well is forced to be flooded and shut down. This problem is particularly prominent in blocks with thin interlayers and poor separation, seriously affecting the development effect of the block and restricting the overall development benefit. Summary of the Invention

[0003] In order to effectively avoid the upward water channeling at the top of the heavy oil thermal recovery well and casing damage, extend the production cycle of the oil well, and ensure the normal production of the oilfield, the present invention proposes a system and a treatment method for preventing and controlling the upward water channeling at the top of a heavy oil thermal recovery well and casing damage.

[0004] In a first aspect, an embodiment of the present invention provides a system for preventing and controlling the upward water channeling at the top of a heavy oil thermal recovery well and casing damage, which may include: a water layer plugging tool, a casing tool string, and a tubing tool string;

[0005] Wherein, the water layer plugging tool is used for performing open-hole pretreatment on the water layer during the drilling stage to plug the water layer; the casing tool string is used for preventing casing deformation and strengthening the cement sheath during the completion stage; and the tubing tool string is used for plugging the interlayer after the upward water channeling at the top during the production stage.

[0006] Optionally, the water layer plugging tool may include: a first central tube, a power supply assembly, a first sealing assembly, and an adjustment assembly that are sequentially sleeved outside the central tube, a release cylinder and a commutation mechanism located inside the first central tube, and a protection tube assembly fixedly connected to the lower end of the release cylinder;

[0007] Both ends of the power supply assembly and the adjustment assembly limit the first sealing assembly, and the limiting cylinder of the adjustment assembly is fixed on the first central tube; the lower protection tube of the protection tube assembly is threadedly connected to the limiting cylinder; the limiting block of the commutation mechanism is fixed on the release cylinder;

[0008] The power supply assembly is used to act on the first sealing assembly to seal the first sealing assembly; the reversing mechanism is used to adjust the position of the sealing ball in the unsealing cylinder so that the plugging agent can seal the formation through the protective tube assembly; the unsealing cylinder is pressed to move downward to act on the reversing mechanism to drive the protective tube assembly and the adjusting assembly to move downward, so that the first sealing assembly is unsealed.

[0009] Optionally, the power supply assembly may include: a hydraulic cylinder, a first piston cylinder, a first wedge ring, a first locking ring, a first retaining ring and a first shear pin;

[0010] Among them, the hydraulic cylinder is sleeved on the outer side of the first center tube and is threadedly connected to the upper end of the first center tube; the first piston cylinder is sleeved between the first center tube and the hydraulic cylinder; the first wedge ring and the first locking ring are respectively located between the hydraulic cylinder and the first piston cylinder, the first locking ring abuts against the lower end of the first wedge ring and bites with the first piston cylinder to limit the first piston cylinder; the first retaining ring is sleeved on the outer side of the first piston cylinder, abuts against the first locking ring, and is threadedly connected to the hydraulic cylinder; the first shear pin passes through the hydraulic cylinder and the first retaining ring respectively and is connected to the first piston cylinder; the lower end of the first piston is adjacent to the first sealing assembly.

[0011] Optionally, the inner surface of the first locking ring is provided with engaging teeth to engage with the first piston.

[0012] Optionally, the power supply assembly may further include: the first piston ring located between the lower end of the first piston cylinder and the first sealing assembly;

[0013] The first piston ring is connected to the lower end of the first piston cylinder.

[0014] Optionally, the first sealing assembly may include: a first rubber sleeve sleeve, a first sealing rubber sleeve, and a first spacer ring; one of the first rubber sleeve sleeves is located between the first sealing rubber sleeve and the first piston ring of the power supply assembly, and one of the first rubber sleeve sleeves is located between the first sealing rubber sleeve and the first adjusting ring of the adjusting assembly; the first spacer ring is located between the two first sealing rubber sleeves;

[0015] The adjustment assembly may include: a first adjustment ring, a limiting cylinder and a second shear pin; the first adjustment ring abuts against the first rubber tube sheath; the limiting cylinder is fixed to the first center tube through the second shear pin; the first adjustment ring is threadedly connected to the limiting cylinder, so as to adjust the distance between the power supply assembly and the first sealing assembly by adjusting the position of the first adjustment ring;

[0016] and / or,

[0017] The protective tube assembly may include: a lower protective tube, a protective tube shoe and a third shear pin; the inner side of the lower protective tube is sleeved on the unsealing tube and fixed by the third shear pin; the protective tube shoe is threadedly connected to the lower end of the lower protective tube, and a plurality of flow holes are opened on the protective tube shoe.

[0018] Optionally, the adjustment assembly may further include: a limiting ring located between the limiting cylinder and the first center tube, the limiting ring being threadedly connected to the lower end of the first center tube and being used to limit the stroke of the limiting cylinder.

[0019] Optionally, the reversing mechanism may include: a reversing cylinder, a limiting block, a limiting pin and an elastic component;

[0020] The reversing cylinder is sleeved inside the unsealing cylinder, and a first reversing groove is opened on the surface of the reversing cylinder; the limit block is fixed on the unsealing cylinder, one end of the limit pin is fixed on the limit block, and the other end is located in the first reversing groove; the elastic component is sleeved on the unsealing cylinder, one end of the bottom is on the unsealing cylinder, and the other end is abutted against the limit block;

[0021] Under the action of the wellhead pressure and the elastic component, the limiting pin slides in the first reversing groove, so that the reversing cylinder opens or closes the flow hole on the unsealing cylinder.

[0022] Optionally, the reversing mechanism may further include: a bearing assembly sleeved on the outside of the reversing cylinder;

[0023] The bearing assembly may include: a bearing, an upper bearing retaining ring and a lower bearing retaining ring;

[0024] The elastic component may include: an elastic member, an upper retaining ring of the elastic member, and a lower retaining ring of the elastic member;

[0025] The limit block, the upper retaining ring of the elastic member, the upper retaining ring of the bearing, the bearing, the lower retaining ring of the bearing, the elastic member and the lower retaining ring of the elastic member are abutted in sequence, and the lower retaining ring of the elastic member is threadedly connected to the unsealing cylinder.

[0026] Optionally, the water layer plugging tool may further include: a first upper joint, which is sleeved on the outer side of the upper end of the first center pipe and threadedly connected to the first center pipe; the first upper joint is used to connect the water layer plugging tool to an external drill pipe.

[0027] Optionally, the casing tool string may include: casing, at least two thermal compensators, casing anchors, or at least one deformation buffer tool, at least one cement ring reinforcement tool, and at least one mechanical switch type casing sliding sleeve;

[0028] The thermal compensator, the deformation buffer tool, the cement ring reinforcement tool, the mechanical switch type casing sliding sleeve, the thermal compensator and the casing anchor are connected in sequence through the casing;

[0029] The buffer rubber tube of the deformation buffer tool is used to abut against the cementing cement ring to isolate the cementing cement ring from the casing;

[0030] The cement ring reinforcement tool is used to reinforce the cement ring of the cementing;

[0031] The mechanical switch type casing sliding sleeve is used to connect the inside and outside of the casing tool string.

[0032] Optionally, the deformation buffer tool may include: a second upper joint, a second center tube, a vulcanized rubber ring, a second rubber tube sheath and a buffer rubber tube;

[0033] Among them, the second upper joint is threadedly connected to the upper part of the second center tube for external casing; the outer side of the second center tube is sequentially sleeved with a vulcanized rubber ring, a second rubber tube sheath, a buffer rubber tube, a second rubber tube sheath and a vulcanized rubber ring; the vulcanized rubber ring and the second center tube are vulcanized.

[0034] Optionally, the cement ring reinforcement tool may include: a third upper joint, a third center pipe, a first lower joint, and a piston cylinder, a second piston ring, a second sealing assembly, a second adjusting ring, which are sequentially sleeved on the outside of the third center pipe, a second piston cylinder, a second wedge ring, a second locking ring, a second retaining ring, and a fourth shear pin located between the third center pipe and the piston cylinder;

[0035] The third upper joint, the third central pipe and the first lower joint are threadedly connected in sequence;

[0036] The piston cylinder and the third center tube are threadedly connected, and the chamber between the piston cylinder and the third center tube is connected through the flow hole on the third center tube; the second piston cylinder is located between the third center tube and the piston cylinder; the second wedge ring is inserted between the second piston cylinder and the piston cylinder to limit the filling of the second piston cylinder; the second locking ring abuts against the second wedge ring and bites with the second piston cylinder to limit the second piston cylinder; the second retaining ring is adjacent to the second locking ring and is threadedly connected to the piston cylinder to limit the second locking ring; the fourth shear pin passes through the piston cylinder and the second retaining ring and is connected to the second piston cylinder; the lower end of the second piston cylinder is connected to the second piston ring;

[0037] Under the pressure of fluid injected at the wellhead, the high-pressure fluid squeezes the second piston cylinder to shear off the fourth shear pin, and drives the second piston ring to squeeze the second sealing assembly to enable the second sealing rubber cylinder in the second sealing assembly to squeeze the cementing cement ring and thus reinforce the cementing cement ring.

[0038] Optionally, the second sealing assembly may include: a third rubber tube sheath, a second sealing rubber tube, a third rubber tube sheath, a second spacer ring, a third rubber tube sheath, a second sealing rubber tube, and a third rubber tube sheath, which are sequentially sleeved on the outside of the third central tube;

[0039] The upper third rubber sleeve sleeve abuts against the second piston ring, and the lower third rubber sleeve sleeve abuts against the second adjustment ring.

[0040] Optionally, the mechanical switch type casing sliding sleeve may include: a fourth upper joint, a sealing cylinder, a positioning cylinder and a second lower joint which are threadedly connected in sequence, and a switch cylinder located inside the sealing cylinder and the positioning cylinder, wherein the upper and lower ends of the switch cylinder are limited by the fourth upper joint and the second lower joint;

[0041] The sealing cylinder is provided with a plurality of first sealing holes, and the first sealing holes are used to be filled with anti-fouling fillers;

[0042] The inner side of the positioning cylinder is provided with an upper clamping groove and a lower clamping groove; the inner side of the switch cylinder is provided with a switch clamping groove, the lower part of the switch cylinder is a cage-like structure, and the outer side of the lower part of the switch cylinder is provided with a positioning protrusion;

[0043] The sleeve switch tool of the tubing tool string cooperates with the switch slot so that under the action of external force, the cage structure of the switch barrel contracts to push the positioning protrusion from the upper slot to the lower slot to open the first sealing hole.

[0044] Optionally, the tubing tool string may include: a tubing, a sleeve switch tool, a sealing nipple, an in-pipe packer and a sealing seat that are threadedly connected in sequence;

[0045] The sleeve switch tool is used to open the mechanical switch type sleeve in the sleeve tool string to inject anti-fouling filler;

[0046] The sealing nipple is provided with a second sealing hole matching the first sealing hole on the sealing cylinder of the mechanical switch type casing sliding sleeve;

[0047] The in-pipe packer is used to perform in-pipe sealing on the casing tool string;

[0048] When the in-pipe packer is set in the casing tool string, the plugging material injected from the oil pipe enters the barrier layer through the second sealing hole and the first sealing hole in sequence to achieve the blocking of the barrier layer.

[0049] Optionally, the sliding sleeve switch tool may include: a fifth upper joint, a fourth center tube, a first upper limit sleeve, a first righting seat, a first righting block, a first righting spring and a first lower limit sleeve;

[0050] The fifth upper joint is threadedly connected to the fourth center pipe, the upper portion of the fifth upper joint is connected to the oil pipe, and the lower portion of the fourth center pipe is connected to the sealing nipple;

[0051] The first straightening seat is sleeved on the outside of the fourth center tube, the first upper limit sleeve and the first lower limit sleeve are sleeved on the outside of the fourth center tube and the first straightening seat, and are threadedly connected with the first straightening seat, so as to limit the first straightening seat through the fifth upper joint and the sealing nipple;

[0052] The first straightening seat is provided with a first straightening groove for accommodating the first straightening block and the first straightening spring on the outer side, and the first straightening block is provided with a first spring groove for accommodating the first straightening spring on the inner side. The first straightening block presses the first straightening spring to be installed in the first straightening groove, and both ends of the first straightening block are limited by the first upper limit sleeve and the first lower limit sleeve.

[0053] The first straightening block is used to be embedded in the switch slot on the switch cylinder of the mechanical switch type sleeve sliding sleeve.

[0054] Optionally, the in-pipe packer may include: a sixth upper joint, a fifth central pipe, a third sealing assembly, a third adjusting ring, a limiting sleeve, a sixth central pipe, a slip assembly, a centralizing assembly and a reversing assembly;

[0055] The sixth upper joint is threadedly connected to the fifth center tube, the third sealing assembly, the third adjusting ring and the limiting sleeve are sleeved on the outside of the fifth center tube, the third adjusting ring is abutted against the lower end of the third sealing assembly; the limiting sleeve is threadedly connected to the third adjusting ring and the vertebral body of the slip assembly respectively; the lower end of the fifth center tube is nested in the vertebral body;

[0056] The slip assembly, the straightening assembly and the reversing assembly are sequentially sleeved on the outer side of the sixth central tube, a second reversing groove is provided on the outer side of the lower end of the sixth central tube, and the reversing sliding pin of the reversing assembly is located in the second reversing groove;

[0057] The slip assembly is used to support and seal the in-pipe packer, the straightening assembly is used to straighten the in-pipe packer, and the reversing assembly is used to unseal the in-pipe packer after it is sealed.

[0058] Optionally, the third sealing assembly may include: a third sealing rubber tube and a third spacer ring, wherein the third spacer ring separates adjacent third sealing rubber tubes;

[0059] The slip assembly comprises: a vertebral body, a slip, a slip seat and a slip spring; wherein the vertebral body is sleeved on the outside of the sixth central tube, the slip seat is threadedly connected to the upper end of the second righting seat of the righting assembly, one end of the slip is limited in the groove on the upper part of the slip seat, and the slip spring is respectively connected to the slip and the sixth central tube to limit the slip;

[0060] The righting assembly comprises: a second upper limit sleeve, a second righting seat, a second righting block, a second righting spring and a second lower limit sleeve; wherein, the second upper limit sleeve and the second lower limit sleeve are arranged on the outer sides of the second righting seat and the sixth center tube, and are threadedly connected with the second righting seat; the outer side of the second righting seat is provided with a second righting groove for accommodating the second righting block and the second righting spring, the inner side of the second righting block is provided with a second spring groove for accommodating the second righting spring, the second righting block squeezes the second righting spring to be installed in the second righting groove, and the two ends of the second righting block are limited by the second upper limit sleeve and the second lower limit sleeve;

[0061] and / or,

[0062] The reversing assembly is located between the sixth center tube and the second lower limit sleeve, and the reversing assembly includes: a reversing sliding pin and a reversing sliding ring; the reversing sliding ring is connected to the inner side of the second lower limit sleeve, and one end of the reversing sliding pin is connected to the reversing sliding ring.

[0063] In a second aspect, an embodiment of the present invention provides a method for preventing and controlling underwater channeling and casing damage at the top of a heavy oil thermal recovery well, comprising:

[0064] Use water layer plugging tools to pre-treat the water layer during the drilling stage to plug the water layer;

[0065] During the completion phase, deformation buffer tools and / or cement ring reinforcement tools in the casing tool string are used to prevent casing deformation and / or reinforce cement rings; and the casing tool string is connected to the inside and outside based on a mechanical switch-type casing sliding sleeve in the casing tool string;

[0066] During the production phase, the sleeve switch tool in the tubing tool string is used to open or close the mechanical switch type casing sleeve, and the tubing is plugged in the tubing based on the in-tubing packer in the tubing tool string, and the interlayer is plugged based on the tubing tool string and the casing tool string.

[0067] The beneficial effects of the above technical solution provided in the embodiments of the present invention include at least:

[0068] In the embodiment of the present invention, a system and method for preventing and controlling underwater channeling and casing damage in a heavy oil thermal recovery well are provided. On the one hand, a water layer plugging tool is used to perform open hole pretreatment on the water layer during the drilling stage to achieve effective plugging of the water layer; on the other hand, during the completion stage, casing prestressed pipe string design and optimization are used to avoid casing damage and reduce cement ring damage rate, and deformation buffer and cement ring reinforcement tools are used to enhance the isolation effect and reduce casing damage and cement ring damage; on the other hand, during the production stage, after underwater channeling occurs, the tubing tool string is used to perform interlayer plugging. This can effectively prevent and control casing damage and underwater channeling, extend the production cycle of the oil well, and ensure normal production of the oil field.

[0069] Other features and advantages of the present invention will be described in the following description, and partly become apparent from the description, or understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures particularly pointed out in the written description and the accompanying drawings.

[0070] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0071] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0072] Figure 1 A schematic diagram of water layer pretreatment provided in an embodiment of the present invention;

[0073] Figure 2 A structural diagram of a water layer plugging tool provided in an embodiment of the present invention;

[0074] Figure 3 for Figure 2 One of the partial enlarged pictures;

[0075] Figure 4 for Figure 2 The second partial enlarged picture;

[0076] Figure 5 A structural diagram of a reversing groove provided on the surface of a reversing cylinder provided in an embodiment of the present invention;

[0077] Figure 6A schematic diagram of the structure of a casing tool string for well completion for water top-up and casing damage prevention provided in an embodiment of the present invention;

[0078] Figure 7 A structural diagram of a deformation buffer tool provided in an embodiment of the present invention;

[0079] Figure 8 A structural diagram of a cement sheath reinforcement tool provided in an embodiment of the present invention;

[0080] Fig. 9 A structural diagram of a mechanical switch type casing sliding sleeve provided in an embodiment of the present invention;

[0081] Fig.10 A structural diagram of a tubing tool string provided in an embodiment of the present invention;

[0082] Fig.11 A structural diagram of a sliding sleeve switch tool provided in an embodiment of the present invention;

[0083] Fig.12 A structural diagram of an in-pipe packer provided in an embodiment of the present invention;

[0084] Fig.13 A structural diagram of a second commutation slot provided in an embodiment of the present invention;

[0085] 1-water layer plugging tool; 2-casing tool string; 3-tubing tool string;

[0086] 11-first central tube; 12-power supply assembly; 13-first sealing assembly; 14-adjusting assembly; 15-unsealing cylinder; 16-reversing mechanism; 17-protection tube assembly; 18-first upper joint; 19-first sealing ring;

[0087] 121-hydraulic cylinder; 122-first piston cylinder; 123-first wedge ring; 124-first locking ring; 125-first retaining ring; 126-first shear pin; 127-first piston ring; 131-first rubber cylinder sheath; 132-first sealing rubber cylinder; 133-first spacer ring; 141-limiting cylinder; 142-first adjusting ring; 143-second shear pin; 144-limiting ring; 161-reversing cylinder; 1 62-limiting block; 163-limiting nail; 164-elastic component; 165-bearing component; 1611-first reversing groove; 1641-elastic member; 1642-elastic member upper retaining ring; 1643-elastic member lower retaining ring; 1644-retaining ring connecting ring; 1651-bearing; 1652-bearing upper retaining ring; 1653-bearing lower retaining ring; 171-lower protective tube; 172-protective tube shoe; 173-third shear pin;

[0088] 21-casing; 22-thermal compensator; 23-casing anchor; 24-deformation buffer tool; 25-cement ring reinforcement tool; 26-mechanical switch type casing sliding sleeve; 27-cementing cement ring;

[0089] 241-second upper joint; 242-second center tube; 243-vulcanized rubber ring; 244-second rubber tube sheath; 245-buffer rubber tube; 2501-third upper joint; 2502-third center tube; 2503-first lower joint; 2504-piston cylinder; 2505-second piston ring; 2506-second sealing assembly; 2507-second adjusting ring; 2508-second piston cylinder; 2509-second wedge ring; 2510-second locking ring; 2 511-second retaining ring; 2512-fourth shear pin; 2513-third rubber tube sheath; 2514-second sealing rubber tube; 2515-second spacer ring; 2516-second sealing ring; 261-fourth upper joint; 262-sealing tube; 263-positioning tube; 264-second lower joint; 265-switch tube; 2621-first sealing hole; 2631-upper card slot; 2632-lower card slot; 2651-positioning protrusion; 2652-switch card slot;

[0090] 31-oil pipe; 32-sleeve switch tool; 33-sealing nipple; 34-in-pipe packer; 35-sealing seat;

[0091] 321-fifth upper joint; 322-fourth center tube; 323-first upper limit sleeve; 324-first righting seat; 325-first righting block; 326-first righting spring; 327-first lower limit sleeve; 3241-first righting groove; 3251-first spring groove; 331-second sealing hole;

[0092] 341-sixth upper joint; 342-fifth center tube; 343-third sealing assembly; 344-third adjusting ring; 345-limiting sleeve; 346-sixth center tube; 347-cava assembly; 348-rightening assembly; 349-reversing assembly; 3431-third sealing rubber cylinder; 3432-third spacer ring; 3461-second reversing groove; 3471-vertebral body; 3472-cava; 3473-cava seat; 3474-cava spring; 3481-second upper limiting sleeve; 3482-second righting seat; 3483-second righting block; 3484-second righting spring; 3485-second lower limiting sleeve; 3486-second righting groove; 3487-second spring groove; 3491-reversing slide pin; 3492-reversing slide ring. DETAILED DESCRIPTION

[0093] The exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art.

[0094] In the description of the present invention, it should be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside", "far", "near", "front", "back" and the like indicate positions or positional relationships based on the positions 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 element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0095] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0096] The purpose of the embodiments of the present invention is to provide a complete set of technical solutions for preventing and controlling top water leakage and casing damage in oil pumping thermal recovery wells, which involve the drilling stage, completion stage and production stage, and can effectively prevent and control the problems of casing damage and top water leakage, thereby extending the production cycle of the oil well and ensuring the normal production of the oil field.

[0097] In an embodiment of the present invention, a system for preventing and controlling underwater channeling and casing damage at the top of a heavy oil thermal recovery well is provided. The system may include: a water layer plugging tool 1, a casing tool string 2 and an oil pipe tool string 3; wherein the water layer plugging tool 1 is used to perform open hole pretreatment on the water layer in the drilling stage to plug the water layer; the casing tool string 2 is used to prevent deformation of the casing 21 and reinforce the cement ring of the cementing in the completion stage; and the oil pipe tool string 3 is used to perform interlayer plugging after underwater channeling at the top of the well in the production stage.

[0098] The above-mentioned heavy oil thermal recovery well top water channeling and casing damage prevention system provided in the embodiment of the present invention, on the one hand, uses the water layer plugging tool to perform open hole pretreatment on the water layer during the drilling stage to achieve effective plugging of the water layer; secondly, in the completion stage, the casing prestressed pipe string design and optimization are used to avoid casing damage and reduce the cement ring damage rate, and the deformation buffer and cement ring reinforcement tools are used to enhance the sealing effect and reduce casing damage and cement ring damage; thirdly, in the production stage, after the top water channeling occurs, the oil pipe tool string is used to perform interlayer plugging. Therefore, it can effectively prevent and control the problems of casing damage and top water channeling, extend the production cycle of the oil well, and ensure the normal production of the oil field.

[0099] In an alternative embodiment, referring to Figure 1 As shown, during the drilling stage, if the drilling reaches the water layer, it is necessary to effectively seal the upper part of the water layer, that is, first use the water layer sealing tool in the embodiment of the present invention to isolate the water layer and the upper rock layer, and then inject water machine plugging agent and high temperature resistant plugging agent through the drill pipe to seal the water layer to prevent the top water from flowing downward. Figure 2 As shown, the water layer plugging tool 1 may include: a first central tube 11, a power supply assembly 12, a first sealing assembly 13 and an adjusting assembly 14 which are respectively sleeved on the outer side of the central tube in sequence, an unsealing cylinder 15 and a reversing mechanism 16 located inside the first central tube 11, and a protective tube assembly 17 fixedly connected to the lower end of the unsealing cylinder 15; both ends of the power supply assembly 12 and the adjusting assembly 14 limit the first sealing assembly 13, and the limiting cylinder 141 of the adjusting assembly 14 is fixed on the first central tube 11; The lower protective tube 171 is threadedly connected to the limiting tube 141; the limiting block 162 of the reversing mechanism 16 is fixed on the unsealing tube 15; the power supply assembly 12 is used to act on the first sealing assembly 13, so that the first sealing assembly 13 is sealed; the reversing mechanism 16 is used to adjust the position of the sealing ball in the unsealing tube 15, so that the plugging agent can seal the formation through the protective tube assembly 17; the unsealing tube 15 is pressed to move downward, so as to act on the reversing mechanism 16 to drive the protective tube assembly 17 and the adjusting assembly 14 to move downward, so that the first sealing assembly 13 is unsealed.

[0100] The unsealing tube in this embodiment is inserted into the first central tube, and the two can be connected by the first sealing ring ( Figure 2 and Figure 319 in the figure). Both the center tube and the unsealing tube are in the shape of a tube column, which ensures that the fluid / liquid inside the tool can move downward. The upper end of the unsealing tube in this embodiment is in the shape of a trumpet, and since its inner diameter is smaller than that of the first center tube, it is convenient to receive the sealing ball. The side wall at the upper end of the unsealing tube is provided with a flow hole to ensure that it is connected to both sides of the power supply assembly through the flow hole. In the same way, the reversing tube of the reversing mechanism is inserted into the inside of the unsealing tube, and is sealed with the unsealing tube by a sealing ring. Its upper end is also in the shape of a trumpet, and is also used to receive the sealing ball. When setting the seal, a sealing ball is put into the first center tube, the diameter of the sealing ball is smaller than the inner diameter of the unsealing tube, but larger than the inner diameter of the reversing tube. The sealing ball blocks the upper part of the reversing tube, and the fluid enters the power supply assembly from the flow hole on the upper side wall of the unsealing tube, so that the first sealing assembly is expanded and sealed.

[0101] The water layer plugging tool in the embodiment of the present invention is used in the drilling stage, and can achieve the sealing of the open hole well through the cooperation of the power supply component and the first sealing component; the position and gap between the various components can be adjusted through the adjustment component to achieve the axial tight installation between the various components. The position of the reversing cylinder is adjusted through the reversing mechanism to achieve the plugging and unblocking.

[0102] In another alternative embodiment, referring to Figure 2 and Figure 3 As shown, the power supply assembly 12 may include: a hydraulic cylinder 121, a first piston cylinder 122, a first wedge ring 123, a first locking ring 124, a first retaining ring 125 and a first shear pin 126; wherein the hydraulic cylinder 121 is sleeved on the outside of the first center tube 11 and is threadedly connected to the upper end of the first center tube 11; the first piston cylinder 122 is sleeved between the first center tube 11 and the hydraulic cylinder 121; the first wedge ring 123 and the first locking ring 124 are respectively located between the hydraulic cylinder 121 and Between the first piston cylinder 122, the first locking ring 124 abuts against the lower end of the first wedge ring 123 and bites with the first piston cylinder 122 to limit the first piston cylinder 122; the first retaining ring 125 is sleeved on the outside of the first piston cylinder 122, abuts against the first locking ring 124, and is threadedly connected to the hydraulic cylinder 121; the first shear pin 126 passes through the hydraulic cylinder 121 and the first retaining ring 125 respectively and is connected to the first piston cylinder 122; the lower end of the first piston is adjacent to the first sealing assembly 13.

[0103] The first wedge ring in this embodiment is inserted between the hydraulic cylinder and the first piston cylinder to play a filling and limiting role, and the first locking ring limits the first wedge ring. In specific implementation, the first locking ring can be an open steel ring made of spring steel, and its inner surface is provided with engaging teeth to engage with the first piston, that is, the inner side thereof is processed with serrated locking teeth, which cooperate with the locking teeth on the inner side of the first piston cylinder, and only allow the first piston cylinder to move axially downward, and cannot recover naturally. The first retaining ring is threadedly connected to the hydraulic cylinder to ensure that the first locking ring will not move with the first piston cylinder, and play a limiting role. Furthermore, a mounting hole is provided at the lower end of the first retaining ring to facilitate the installation of the first shear pin.

[0104] It should be noted that the first shear pins in this embodiment may be multiple, and are axially arranged at the connection between the first retaining ring and the hydraulic cylinder, and partially extend to the first piston cylinder after penetrating the two, playing a limiting role. When the first piston cylinder is not subjected to force or is subjected to a small axial downward force, the entire tool remains in its original state; when the first piston cylinder is subjected to a downward thrust reaching a preset value, the first shear pins are cut off, and the first piston cylinder moves downward to push other components connected to or adjacent to the first piston cylinder (i.e., the connected first piston ring).

[0105] In an alternative embodiment, referring to Figure 2 and Figure 3 As shown, the power supply assembly 12 may further include: a first piston ring 127 located between the lower end of the first piston cylinder 122 and the first sealing assembly 13; the first piston ring 127 is connected to the lower end of the first piston cylinder 122. The first piston ring and the first piston cylinder in this embodiment may be threadedly connected, which plays a role in limiting and increasing the force-bearing area.

[0106] In an alternative embodiment, referring to Figure 2 and Figure 4 As shown, the first sealing assembly 13 may include: a first rubber cylinder sleeve 131, a first sealing rubber cylinder 132, and a first spacer ring 133; one first rubber cylinder sleeve 131 is located between the first sealing rubber cylinder 132 and the first piston ring 127 of the power supply assembly 12, and one first rubber cylinder sleeve 131 is located between the first sealing rubber cylinder 132 and the first adjustment ring 142 of the adjustment assembly 14; the first spacer ring 133 is located between the two first sealing rubber cylinders 132.

[0107] The first rubber sleeve sheath in the embodiment of the present invention can be made of copper or other softer metals to protect the first sealing rubber sleeve. The first sealing rubber sleeve can be made of rubber. According to the use temperature, sealing pressure and other factors, it can be made of nitrile rubber, hydrogenated nitrile rubber, fluororubber, etc., or graphite + nickel wire, etc. The first sealing rubber sleeve can be deformed within a certain range to play a sealing role. The first spacer ring is sleeved between the two groups of first sealing rubber sleeves to play a separation role.

[0108] In an alternative embodiment, referring to Figure 2 and Figure 4 As shown, the adjustment assembly 14 may include: a first adjustment ring 142, a limiting cylinder 141 and a second shear pin 143; the first adjustment ring 142 abuts against the first rubber tube sleeve 131; the limiting cylinder 141 is fixed to the first center tube 11 through the second shear pin 143; the first adjustment ring 142 is threadedly connected to the limiting cylinder 141, so as to adjust the distance between the power supply assembly 12 and the first sealing assembly 13 by adjusting the position of the first adjustment ring 142.

[0109] In the embodiment of the present invention, the above-mentioned limiting cylinder is fixed to the first central tube by the second shear pin in the initial state, and its position is fixed. The first adjustment ring is located between the limiting cylinder and the first rubber tube sheath below, and the first adjustment ring is threadedly connected to the limiting cylinder. In the specific implementation, the positions of the various components sleeved on the outer side of the first central tube are adjusted by adjusting the amount of screwing in and out of the two threads, thereby filling the gap and ensuring that the various components are tightly installed axially.

[0110] In an alternative embodiment, referring to Figure 2 and Figure 4 As shown, the adjustment assembly 14 may further include: a limiting ring 144 located between the limiting cylinder 141 and the first center tube 11, the limiting ring 144 is threadedly connected to the lower end of the first center tube 11, and is used to limit the stroke of the limiting cylinder 141. The limiting cylinder in this embodiment has a step at the upper end, and the limiting ring is threadedly connected to the lower end of the first center tube, and the stroke of the limiting cylinder is limited by the limiting ring to prevent the limiting cylinder from falling out.

[0111] In an alternative embodiment, referring to Figure 2 and Figure 4 As shown, the protective tube assembly 17 may include: a lower protective tube 171, a protective tube shoe 172 and a third shear pin 173; the inner side of the lower protective tube 171 is sleeved on the unsealing tube 15 and fixed by the third shear pin 173; the protective tube shoe 172 is threadedly connected to the lower end of the lower protective tube 171, and a plurality of flow holes are opened on the protective tube shoe 172.

[0112] In this embodiment, the outer side of the lower protective tube is connected to the limiting cylinder by a threaded connection, the inner side of the lower protective tube is sleeved on the unsealing cylinder, and is limited by a third shear pin, and the lower end of the lower protective tube is connected to the protective tube shoe by a threaded connection. A number of flow holes are designed on the protective tube shoe to ensure the circulation of liquid inside and outside the tool. The lower protective tube plays a protective and limiting role.

[0113] In an alternative embodiment, referring to Figure 2 and Figure 4 As shown, the reversing mechanism 16 may include: a reversing cylinder 161, a limit block 162, a limit pin 163 and an elastic component 164; the reversing cylinder 161 is sleeved inside the unsealing cylinder 15, and a first reversing groove 1611 is opened on the surface of the reversing cylinder 161; the limit block 162 is fixed on the unsealing cylinder 15, one end of the limit pin 163 is fixed on the limit block 162, and the other end is located in the first reversing groove 1611; the elastic component 164 is sleeved on the unsealing cylinder 15, one end of the bottom is in contact with the unsealing cylinder 15, and the other end is in contact with the limit block 162; under the action of the wellhead pressure and the elastic component 164, the limit pin 163 of the reversing cylinder 161 slides in the first reversing groove 1611, so that the reversing cylinder 161 opens or closes the flow hole on the unsealing cylinder 15.

[0114] In this embodiment, a limit block installation position is provided on the upper part of the unsealing cylinder to fix the limit block on the unsealing cylinder, and one end of the limit pin is fixed on the limit block, so that the unsealing cylinder, the limit block and the limit pin move together. Figure 5 As shown, it includes a long slot, a short slot and a reversing inclined surface. The end of the above-mentioned limiting pin away from the limiting block can be cylindrical to cooperate with the first reversing slot, and then the position between the reversing cylinder and the unsealing cylinder can be changed under the action of external force.

[0115] In an alternative embodiment, referring to Figure 2 and Figure 4 As shown, the reversing mechanism 16 also includes: a bearing 1651 assembly 165 sleeved on the outside of the reversing cylinder 161; the bearing assembly 165 may include: a bearing 1651, an upper retaining ring 1652 of the bearing and a lower retaining ring 1653 of the bearing; the elastic assembly 164 may include: an elastic member 1641, an upper retaining ring 1642 of the elastic member and a lower retaining ring 1643 of the elastic member; the limit block 162, the upper retaining ring 1642 of the elastic member, the upper retaining ring 1652 of the bearing, the bearing 1651, the lower retaining ring 1653 of the bearing, the elastic member 1641 and the lower retaining ring 1643 of the elastic member are abutted in sequence, and the lower retaining ring 1643 of the elastic member is threadedly connected to the unsealing cylinder 15.

[0116] It should be noted that the elastic member in this embodiment can be a disc spring or an ordinary coil spring. The upper retaining ring of the elastic member and the reversing cylinder can be connected by threads to limit the upper end of the elastic member; the bearing assembly is used to abut between the reversing cylinder and the unsealing cylinder to facilitate the rotation of the reversing cylinder relative to the unsealing cylinder in the circumferential direction during the sliding of the limiting pin in the first reversing groove. Figure 2 and Figure 4 As shown, if the lower retaining ring of the elastic member is not fixedly connected to the unsealing cylinder 15, this embodiment can be connected to the bottom of the unsealing cylinder 15 through the retaining ring connecting ring 1644 to limit the lower retaining ring 1643 of the elastic member.

[0117] Reference Figure 2 to Figure 5 As shown, the working process of the water layer plugging tool in this embodiment is as follows: in the initial state of the tool, under the action of the elastic member 1641, the limiting pin 163 is located in a groove of the C line, and the inside and outside of the tool are connected. When used on site, the plugging tool is connected to the lower end of the drill pipe, and the drill pipe is used to send it down to the water layer, and the plugging ball of the reversing cylinder 161 is put in, the central flow channel of the tool is blocked, and water is injected into the wellhead to pressurize. Under the action of the high-pressure fluid, the position of the limit pin 163 remains unchanged, and the reversing cylinder 161 moves downward, so that the limit pin enters the short groove and gradually reaches the B line. The high-pressure fluid reaches the hydraulic cylinder 121 through the flow hole on the unsealing cylinder and the first center tube, and acts on the first piston cylinder 122, pushing the first piston cylinder 122 axially downward. When the axial force reaches a certain value, the first shear pin 126 is cut off, and the first piston cylinder 122 drives the first piston ring 127 to move downward, acting on the first sealing rubber cylinder 132. The rubber cylinder is axially compressed, radially expanded, and expanded outward to fill the space between the tool and the wellbore, that is, the setting is realized and the sealing effect is played. Under the action of the first locking ring 124, the pressure is stopped at this time, and each component still maintains the state before the pressure is stopped, and the sealing is continued. After the sealing is completed, the pressure from the wellhead disappears, and the reversing cylinder 161 moves upward under the action of the elastic member 1641, and the limit pin returns to the C line under the action of the reversing inclined surface. At this time, the wellhead is injected with plugging and squeezing, and the reversing cylinder 161 moves downward again. The limit pin enters the long groove and reaches the A line. The reversing cylinder 161 moves downward with a large displacement, and the flow hole in the middle of the unsealing cylinder 15 is exposed. The plugging agent passes through the flow hole, through the gap between the limit blocks 162, the flow hole on the limit cylinder 141, and the flow hole on the protective shoe 172, and enters the water layer for sealing. After the plugging is completed, the wellhead is depressurized, the plugging ball of the unsealing tube 15 is put into the well, and water is injected again to pressurize the well. The whole unsealing tube 15 moves downward, the second shear pin 143 and the third shear pin 173 are sheared, and the limit block 162 drives the lower protective pipe 171 and the limit tube 141 to move downward, and the first sealing rubber tube 132 expands axially and contracts radially to achieve unsealing, and the pipe string is pulled out to complete the water layer pretreatment.

[0118] In an alternative embodiment, referring to Figure 2 and Figure 3 As shown, the water layer plugging tool 1 may further include: a first upper joint 18, which is sleeved on the outer side of the upper end of the first central pipe 11 and threadedly connected to the first central pipe 11; the first upper joint 18 is used to connect the water layer plugging tool 1 to a drill pipe.

[0119] In an optional embodiment, after completion, a casing tool string needs to be run into the open hole. To address the problem of casing fragility or loosening of cement ring to produce cracks, the present invention uses a casing tool string for completion that can prevent water flow and casing damage. Figure 6 As shown, the casing tool string 2 may include: casing 21, at least two thermal compensators 22, casing anchor 23, or at least one deformation buffer tool 24, at least one cement ring reinforcement tool 25, and at least one mechanical switch type casing sleeve 26; the thermal compensator 22, the deformation buffer tool 24, the cement ring reinforcement tool 25, the mechanical switch type casing sleeve 26, the thermal compensator 22 and the casing anchor 23 are connected in sequence through the casing 21; the buffer rubber tube 245 of the deformation buffer tool 24 is used to abut on the cementing cement ring to isolate the cementing cement ring 27 from the casing 21; the cement ring reinforcement tool 25 is used to reinforce the cementing cement ring 27; the mechanical switch type casing sleeve 26 is used to connect the inside and outside of the casing tool string 2.

[0120] The above-mentioned deformation buffer tool, cement ring reinforcement tool and mechanical switch type casing sleeve in this embodiment are arranged according to the specific downhole working conditions. There may be multiple, one, or no arrangement. During the use of the tubing string, it can be selected whether to use a certain part, or the position and number of the tools can be adjusted according to the wellbore structure and actual conditions, in order to achieve the best use effect. This embodiment does not make specific limitations on this.

[0121] The thermal recovery casing head in the embodiment of the present invention has the characteristics of retractable threaded sealing, which is not only suitable for prestressed construction, but also allows the oil layer casing to rise, thereby protecting the upper casing string and wellhead device of the oil well. The device is not affected by high temperature, has reliable sealing, and is installed at the uppermost end of the completion string.

[0122] The casing is a thermal recovery casing, that is, a special casing for thermal recovery wells. Since the material of ordinary API steel grade N80 and P110 casing is C-Mn steel with poor thermal stability, the casing on the water layer uses non-API series casing TP100H. Non-API series casing TP100H uses Cr-Mo low-alloy steel with good thermal stability as the casing material, which has good thermal stability. The casing in the oil layer uses thick-walled casing (TP120), which is used in the oil layer section of the super-heavy oil block with more gas injection rounds and severe sand production, which can increase the casing strength and further prevent casing damage.

[0123] Thermal compensators are effective tools for solving local casing damage. They are installed at the upper and lower interfaces of the interlayer, and are mainly used to compensate for the axial, lateral, and angular thermal deformation of the casing. They can effectively alleviate the thermal stress changes of the casing string in the local section, and reduce the thermal stress to the stress range that the casing can withstand, so as to reduce casing damage. The tool is simple to construct and does not affect prestressed completion.

[0124] Prestressed casing ground anchor is used for prestressed completion. Since the casing will stretch during the heating process, in order to avoid the casing from being damaged during the thermal recovery process, appropriate prestress is applied to the casing during the completion process to overcome part of the thermal stress, so that the thermal stress on the casing does not exceed the yield limit of the casing. This completion method is called prestressed completion, which is widely used in the completion process of thermal recovery wells and plays an important role in preventing the damage of the casing in the whole well and the rise of the wellhead. When the tool is used, it is installed at the lowest end of the casing string and directly connected to the casing. After reaching the bottom of the well, the pump is turned on for circulation. After a series of actions such as normal cementing, collision pressure, and pressure holding, the tool anchor claw opens and anchors to the well wall. Under the pressure holding state, the wellhead is pulled up to the designed tonnage or length, and the casing is solidified in a prestressed manner to complete the casing prestressing construction.

[0125] The cement ring is injected with high temperature resistant cement slurry. The steam injection temperature of heavy oil wells is 350℃, and ordinary oil well cement cannot withstand such high temperature. High temperature resistant cement slurry has the characteristics of high temperature resistance, slight expansion, good toughness and low cost, which basically meets the requirements of steam injection thermal recovery wells and can be widely used in thermal recovery well cementing construction.

[0126] In an alternative embodiment, referring to Figure 7 As shown, the deformation buffer tool 24 includes: a second upper joint 241, a second center tube 242, a vulcanized rubber ring 243, a second rubber tube sheath 244 and a buffer rubber tube 245; wherein, the second upper joint 241 is threadedly connected to the upper part of the second center tube 242 for externally connecting the sleeve 21; the outer side of the second center tube 242 is sequentially sleeved with the vulcanized rubber ring 243, the second rubber tube sheath 244, the buffer rubber tube 245, the second rubber tube sheath 244 and the vulcanized rubber ring 243; the vulcanized rubber ring 243 and the second center tube 242 are vulcanized and connected.

[0127] In the embodiment of the present invention, each component on the outer side of the second central tube is glued to the second central tube, and the vulcanized rubber ring is fixed to the second central tube by vulcanization. Among them, the core component buffer rubber tube should be made of high temperature resistant sealing material to ensure that it will not deteriorate and be damaged under high temperature conditions, and has good elasticity and toughness to buffer thermal expansion and deformation between the cement ring and the casing, and prevent damage to the cement ring and the casing.

[0128] In an alternative embodiment, referring to Figure 8As shown, the cement ring reinforcement tool 25 may include: a third upper joint 2501, a third center pipe 2502, a first lower joint 2503, and a piston cylinder 2504, a second piston ring 2505, a second sealing assembly 2506, a second adjusting ring 2507, which are sequentially sleeved on the outside of the third center pipe 2502, a second piston cylinder 2508, a second wedge ring 2509, a second locking ring 2510, a second retaining ring 2511, and a fourth shear pin 2512 located between the third center pipe 2502 and the piston cylinder 2504; wherein the third upper joint 2501, the third center pipe 2502 and the first lower joint 2503 are threadedly connected in sequence; the piston cylinder 2504 and the third center pipe 2502 are threadedly connected, and the chamber between the piston cylinder 2504 and the third center pipe 2502 is connected through the flow hole on the third center pipe 2502; the second piston cylinder 2508 is located between the third center pipe 2502 and the piston cylinder 2504; The second wedge ring 2509 is inserted between the second piston cylinder 2508 and the piston cylinder 2504 to limit the filling of the second piston cylinder 2508; the second locking ring 2510 is in contact with the second wedge ring 2509 and bites with the second piston cylinder 2508 to limit the position of the second piston cylinder 2508; the second retaining ring is adjacent to the second locking ring 2510 and is threadedly connected to the piston cylinder 2504 to limit the position of the second locking ring 2510; the fourth shear pin 2512 passes through the piston cylinder 2504 and the second retaining ring are connected to the second piston cylinder 2508; the lower end of the second piston cylinder 2508 is connected to the second piston ring 2505; under the pressure of the fluid injected at the wellhead, the high-pressure fluid squeezes the second piston cylinder 2508 to shear off the fourth shear pin 2512, and drives the second piston ring 2505 to squeeze the second sealing assembly 2506 to achieve the second sealing rubber cylinder 2514 in the second sealing assembly 2506 to squeeze the cementing cement ring and then reinforce the cementing cement ring.

[0129] The upper end of the third central tube in the embodiment of the present invention is connected to the third upper joint through a thread, and another set of threads is connected to the piston cylinder on the lower outer side, and a second sealing ring ( Figure 82516) seal. The piston cylinder and the inner cavity of the tool are connected through the flow hole on the third center tube. The second piston cylinder is inserted between the third center tube and the piston cylinder, and the two are sealed by a sealing ring. The second wedge ring is inserted between the piston cylinder and the piston cylinder to play a filling limit role. The second locking ring is a steel ring with a small opening made of spring steel. The inner side is processed with serrated locking teeth, which cooperate with the locking teeth on the outer side of the second piston cylinder, allowing only the second piston cylinder to move axially downward, and cannot recover naturally. The second retaining ring is connected to the piston cylinder by a threaded connection to ensure that the second locking ring will not move with the piston cylinder, playing a limiting role. The outer side of the upper end is processed with threads to connect with the piston cylinder, and the lower end is designed with a mounting hole to facilitate the installation of the second retaining ring. The fourth shear pin is installed in the piston cylinder and the second retaining ring connection part in a circumferentially uniform state, penetrating the two and part of the second piston cylinder, playing a limiting role. When the second piston cylinder is not subjected to force or only subjected to a small downward axial force, the various parts of the tool remain in their original state. When the downward axial force on the second piston cylinder reaches a certain value, the fourth shear pin is sheared off, and the second piston cylinder moves downward. The second piston ring and the second piston cylinder are connected by threads, which play a role in limiting and increasing the force-bearing area. The second adjustment ring and the first lower joint are connected by threads. The position of each sleeve component on the third center tube is adjusted by the amount of screwing in and out of the threads between the two, filling the gap and ensuring that each component is tightly installed axially. When the tool is in use, high-pressure fluid from inside the tool enters the piston cylinder and pushes the piston tube axially downward. When the axial force reaches a certain value, the shear pin is cut off, and the piston tube drives the piston ring to move downward, acting on the sealing rubber tube part. The rubber tube is axially compressed, radially expanded, and expanded outward, squeezing the cement ring, thereby playing a reinforcing role. Under the action of the locking ring, the pressure is stopped at this time, and each component still maintains the state before the pressure is stopped, and continues to be sealed.

[0130] In an alternative embodiment, referring to Figure 8As shown, the second sealing assembly 2506 may include: a third rubber sleeve sheath 2513, a second sealing rubber sleeve 2514, a third rubber sleeve sheath 2513, a second spacer ring 2515, a third rubber sleeve sheath 2513, a second sealing rubber sleeve 2514, and a third rubber sleeve sheath 2513, which are sequentially sleeved on the outside of the third central tube 2502; the upper third rubber sleeve sheath 2513 abuts against the second piston ring 2505, and the lower third rubber sleeve sheath 2513 abuts against the second adjustment ring 2507. The second sealing rubber sleeve, the third rubber sleeve sheath, and the second spacer ring are installed between the second piston ring and the second adjustment ring. The third rubber sleeve sheath is generally made of copper or other softer metals to protect the sealing rubber sleeve. The sealing rubber sleeve is generally made of rubber. According to factors such as the use temperature and the sealing pressure, it can be made of nitrile rubber, hydrogenated nitrile rubber, fluororubber, etc., or it can be made of materials such as graphite + nickel wire. The sealing rubber sleeve can be deformed within a certain range to play a sealing role. The spacer ring is sleeved between the two sets of sealing rubber tubes to play a separating role.

[0131] In an alternative embodiment, referring to Fig. 9 As shown, the mechanical switch type sleeve sliding sleeve 26 may include: a fourth upper joint 261, a sealing cylinder 262, a positioning cylinder 263 and a second lower joint 264 which are threadedly connected in sequence, and a switch cylinder 265 located inside the sealing cylinder 262 and the positioning cylinder 263, wherein the upper and lower ends of the switch cylinder 265 are limited by the fourth upper joint 261 and the second lower joint 264; a plurality of first sealing holes 2621 are opened on the sealing cylinder 262, and the first sealing holes 2621 are used to fill the anti-fouling filler; the inner side of the positioning cylinder 263 is opened An upper groove 2631 and a lower groove 2632 are provided; a switch groove 2652 is provided on the inner side of the switch cylinder 265, the lower part of the switch cylinder 265 is a cage structure, and a positioning protrusion 2651 is provided on the outer side of the lower part of the switch cylinder 265; the sliding sleeve switch tool 32 of the tubing tool string 3 cooperates with the switch groove, so that under the action of external force, the cage structure of the switch cylinder 265 contracts, so as to push the positioning protrusion 2651 from the upper groove 2631 to the lower groove 2632, so as to realize the opening of the first sealing hole 2621.

[0132] In the embodiment of the present invention, the upper joint, the sealing cylinder, the positioning cylinder and the lower joint are connected in sequence by threads to form a sliding sleeve body. The sealing is ensured by a sealing ring between the connected parts, and anti-loosening pins are drilled and installed. A plurality of sealing holes are opened on the upper part of the sealing cylinder, and anti-fouling fillers are filled in the sealing holes; the interior of the positioning cylinder is designed with two grooves, an upper groove and a lower groove. The switch cylinder is made of high-quality spring steel. This component is installed inside the main body and can move axially inside the main body. A dynamic seal is formed between the two through a sealing ring. A switch groove is arranged in the upper part of the switch cylinder, and the lower part is a cage-type structure, such as Fig. 9As shown in (AA), the cage structure can ensure that this part of the cylinder has both certain strength and good elasticity. The outer layer of the cage structure is designed with a positioning protrusion, which cooperates with the upper and lower grooves inside the positioning cylinder to fix the relative position of the switch cylinder in the main body. When the switch cylinder is in the initial position, the positioning protrusion is located in the upper groove, and the switch cylinder covers the inner side of the sealing hole; under the action of external force, the switch cylinder can move downward, the cage structure is elastically deformed by force, the protrusion shrinks inward, and the protrusion part expands outward when it descends to the position of the lower groove, and the protrusion enters the lower groove. The lower end face of the upper joint and the upper end face of the lower joint play a limiting role. The limiting strength of the two is much greater than the upper and lower grooves, so that the switch cylinder can only move in the axial space between the two. After the protrusion enters the lower groove, it cannot continue to move downward. At this time, the switch cylinder is completely below the sealing hole, realizing the connection between the inside and outside of the sliding sleeve. The anti-fouling filler can be fixed by vulcanization of rubber at room temperature. During cementing, the rubber can prevent cement from entering and making the switch barrel unable to move. After multiple rounds of high-temperature steam intake and discharge, the rubber is damaged but does not affect the opening of the sleeve and the internal and external connections.

[0133] In an alternative embodiment, referring to Fig.10 As shown, the tubing tool string 3 may include: a tubing 31, a sleeve switch tool 32, a sealing nipple 33, an in-tube packer 34 and a sealing seat 35 which are threadedly connected in sequence; the sleeve switch tool 32 is used to open the mechanical switch type casing sleeve 26 in the casing tool string 2 to inject anti-fouling filler; the sealing nipple 33 is provided with a second sealing hole 331 which matches the first sealing hole 2621 on the sealing tube 262 of the mechanical switch type casing sleeve 26; the in-tube packer 34 is used to set the casing tool string 2 in the pipe; when the in-tube packer 34 is set in the casing tool string 2, the sealing material injected by the tubing 31 enters the interlayer through the second sealing hole 331 and the first sealing hole 2621 in sequence to achieve the blocking of the interlayer. During the use of the tubing string, it can be selected whether to use a certain part according to the wellbore structure and actual conditions, or the tool position and quantity can be adjusted to achieve the best use effect.

[0134] In an alternative embodiment, referring to Fig.11As shown, the sliding sleeve switch tool 32 may include: a fifth upper joint 321, a fourth center tube 322, a first upper limit sleeve 323, a first straightening seat 324, a first straightening block 325, a first straightening spring 326 and a first lower limit sleeve 327; the fifth upper joint 321 and the fourth center tube 322 are threadedly connected, the upper part of the fifth upper joint 321 is connected to the oil pipe 31, and the lower part of the fourth center tube 322 is connected to the sealing short section 33; the first straightening seat 324 is sleeved on the outside of the fourth center tube 322, the first upper limit sleeve 323 and the first lower limit sleeve 327 are sleeved on the outside of the fourth center tube 322 and the first straightening seat 324, and are threadedly connected to the first straightening seat 324 , so as to limit the first straightening seat 324 through the fifth upper joint 321 and the sealing short section 33; the outer side of the first straightening seat 324 is provided with a first straightening groove 3241 for accommodating the first straightening block 325 and the first straightening spring 326, and the inner side of the first straightening block 325 is provided with a first spring groove 3251 for accommodating the first straightening spring 326, the first straightening block 325 squeezes the first straightening spring 326 to be installed in the first straightening groove 3241, and the two ends of the first straightening block 325 are limited by the first upper limit sleeve 323 and the first lower limit sleeve 327; the first straightening block 325 is used to be embedded in the switch card slot on the switch cylinder 265 of the mechanical switch type sleeve sliding sleeve 26.

[0135] In the embodiment of the present invention, the upper joint and the center tube are connected by threads to form the center pipe column of the tool, and the upper joint and the center tube are used to connect the upper and lower tools respectively. The straightening seat is sleeved on the outside of the center tube, and can move a short distance in the axial direction under the limiting action of the upper joint and the sealing short section. The sliding sleeve switch tool and the sealing short section are usually used as a whole with threaded connection; the straightening seat is designed with a straightening groove structure for installing the straightening spring and the straightening block. The upper and lower ends of the straightening seat are designed with connecting threads, which can be connected to the upper limit sleeve and the lower limit sleeve respectively, and limited by the two limit sleeves; the straightening block is designed with a cylindrical spring groove inside, which can be installed in conjunction with the straightening spring. The straightening spring has a large stiffness coefficient. Under its elastic action, when no external force is applied, the outer diameter of the straightening block is larger than the inner diameter of the casing of the drilling section. After the casing is lowered, the spring is in a compressed state, which can play a straightening role on the pipe column. When the switch tool is lowered into the well and passes through the switch slot of the mechanical switch-type casing sliding sleeve, the straightening spring is opened, the straightening block expands outward and embeds into the switch slot, the switch tool continues to descend, and the downward axial force drives the switch barrel to descend together, and the positioning protrusion moves downward from the upper slot into the lower slot. Due to the limiting effect of the lower joint, the sliding sleeve switch tool can continue to descend, but the switch barrel is positioned in the lower slot. At this time, the mechanical switch-type casing sliding sleeve is in an open state; conversely, the switch tool moves upward, driving the switch barrel to be positioned in the upper slot, thereby closing the sliding sleeve.

[0136] In an alternative embodiment, referring to Fig.12As shown, the in-pipe sealer 34 may include: a sixth upper joint 341, a fifth center pipe 342, a third sealing assembly 343, a third adjusting ring 344, a limiting sleeve 345, a sixth center pipe 346, a slip 3472 assembly 347, a straightening assembly 348 and a reversing assembly 349; wherein the sixth upper joint 341 and the fifth center pipe 342 are threadedly connected, the third sealing assembly 343, the third adjusting ring 344 and the limiting sleeve 345 are sleeved on the outer side of the fifth center pipe 342, and the third adjusting ring 344 abuts against the lower end of the third sealing assembly 343; the limiting sleeve 345 is respectively connected to the third adjusting ring 344 and the slip 3472 assembly 347, and the straightening assembly 348 and the reversing assembly 349. The vertebral body 3471 of the shoe 3472 assembly 347 is threadedly connected; the lower end of the fifth center tube 342 is nested in the vertebral body 3471; the cava assembly 347, the straightening assembly 348 and the reversing assembly 349 are sequentially sleeved on the outside of the sixth center tube 346, and a second reversing groove 3461 is opened on the outside of the lower end of the sixth center tube 346, and the reversing slide pin 3491 of the reversing assembly 349 is located in the second reversing groove; the cava assembly 347 is used to support and seal the in-pipe packer 34, the straightening assembly 348 is used to straighten the in-pipe packer 34, and the reversing assembly 349 is used to unseal the in-pipe packer 34 after sealing.

[0137] In an alternative embodiment, referring to Fig.12 As shown, the third sealing assembly 343 may include: a third sealing rubber tube 3431 and a third spacer ring 3432 , and the third spacer ring 3432 separates adjacent third sealing rubber tubes 3431 .

[0138] In a specific embodiment, referring to Fig.12 As shown, the cava assembly 347 may include: a vertebral body 3471, a cava 3472, a cava seat 3473 and a cava spring 3474; wherein, the vertebral body 3471 is sleeved on the outer side of the sixth center tube 346, the cava seat 3473 is threadedly connected to the upper end of the second straightening seat 3482 of the straightening assembly 348, one end of the cava 3472 is limited in the groove on the upper part of the cava seat 3773, and the cava spring 3473 is respectively connected to the cava 3472 and the sixth center tube 346 to limit the cava 3472.

[0139] In a specific embodiment, referring to Fig.12As shown, the straightening assembly 348 may include: a second upper limit sleeve 3481, a second straightening seat 3482, a second straightening block 3483, a second straightening spring 3484 and a second lower limit sleeve 3485; wherein, the second upper limit sleeve 3481 and the second lower limit sleeve 3485 are sleeved on the outside of the second straightening seat 3482 and the sixth center tube 346, and are threadedly connected to the second straightening seat 3482; a second straightening groove 3486 for accommodating the second straightening block 3483 and the second straightening spring 3484 is provided on the outside of the second straightening seat 3482, a second spring groove 3487 for accommodating the second straightening spring 3484 is provided on the inside of the second straightening block 3483, the second straightening block 3483 squeezes the second straightening spring 3484 to be installed in the second straightening groove 3486, and both ends of the second straightening block 3483 are limited by the second upper limit sleeve 3481 and the second lower limit sleeve 3485.

[0140] In a specific embodiment, referring to Fig.12 As shown, the reversing assembly 349 is located between the sixth center tube 346 and the second lower limit sleeve 3485, and the reversing assembly 349 may include: a reversing slide pin 3491 and a reversing slip ring 3492; the reversing slip ring 3492 is connected to the inner side of the second lower limit sleeve 3485, and one end of the reversing slide pin 3491 is connected to the reversing slip ring 3492.

[0141] In the embodiment of the present invention, combined with Fig.12 As shown, the upper joint is used to connect the upper tool; the upper part of the center tube is connected to the upper joint by threads, and the lower part is inserted into the vertebral body and limited by a limit sleeve. The center tube and the vertebral body are sealed by a sealing ring, and are fixed with several shear pins. The limit sleeve is connected to the vertebral body by threads, and positioning pins are installed to prevent it from falling off. The sealing rubber tube and the spacer ring are connected to the center tube and fixed by the upper joint and the adjusting ring. The adjusting ring is connected to the limit sleeve by threads and can move axially on the limit sleeve. After the position is adjusted to a suitable position, it is fixed with a drill. The lower part of the vertebral body is connected to the center tube by threads. A reversing track is designed on the center tube, and its structure is as shown in the figure. Fig.13As shown, the track groove is V-shaped and arranged in a circular cycle on the outer surface of the center tube. The structure mainly includes a reversing bevel, a long groove, and a short groove. The slip is installed in the upper groove of the slip seat, and the slip spring is installed on the slip to limit the state and position of the slip; the lower part of the slip seat is connected to the upper end of the straightening seat by a thread, and a straightening groove structure is designed on the straightening seat for installing the straightening block and the straightening spring. The lower end of the straightening seat is connected to the limit sleeve by a thread, and the straightening seat and the limit sleeve can limit the straightening block. A cylindrical spring groove is designed inside the straightening block, which can be installed in conjunction with the straightening spring. The straightening block and the straightening spring can play the role of a straightening tool with the same function as the straightening part in the sliding sleeve switch tool. The reversing slip ring is installed inside the limit sleeve, and the reversing sliding pin is installed inside the reversing slip ring. The reversing sliding pin can slide in the track groove on the center tube. When the tool enters the well, the reversing slide pin should be in the short groove position, and the pipe string is lifted up and lowered. Under the action of the reversing inclined surface, the sealing seat is located at the lowest end of the matching sealing pipe string, playing the role of a guide shoe. A through hole is opened below it and a conical surface is designed inside. When the sealing ball is put into the tool, the sealing ball falls on the conical surface, and the internal and external closure can be achieved under the action of internal pressure.

[0142] When the above-mentioned packer is in use, the matching sealing and injection pipe string is lowered into the well, and the packer and the sleeve switch tool pass through the switch slot successively. Both of them will generate certain resistance when passing through the slot, but compared with the two, the straightening block on the packer is longer, the chamfers at both ends are small, and the straightening force of the straightening spring is small, so only the sleeve switch tool can realize the opening and closing of the sleeve. After the sleeve switch tool is lowered into the well, the sleeve is opened to realize the connection between the inside and outside of the sleeve. Continue to move downward for a distance, lower the upper body of the pipe string to realize the sealing of the packer, and drop the sealing ball. The sealing ball falls on the sealing seat to realize the upper and lower closure. The sealing material is injected into the pipe string. The sealing material enters the interlayer from the oil pipe through the sealing hole and the sealing hole to realize the sealing of the interlayer. After the sealing is completed, the pipe string is lifted up to unseal. When the sleeve switch tool passes through the sleeve, the sleeve is closed, and the pipe string is lifted out of the wellhead to complete the sealing. The sealing pipe string of the mechanical switch type casing sleeve is also used in conjunction with the cement ring reinforcement tool to expand the sealing rubber tube to realize the cement ring reinforcement.

[0143] Based on the same inventive concept, an embodiment of the present invention further provides a method for preventing and controlling underwater channeling and casing damage at the top of a heavy oil thermal recovery well, which may include:

[0144] Use water layer plugging tools to pre-treat the water layer during the drilling stage to plug the water layer;

[0145] During the completion phase, deformation buffer tools and / or cement sheath reinforcement tools in the casing tool string are used to prevent casing deformation and / or reinforce cement sheaths; and, the casing tool string is connected inside and outside based on a mechanical switch-type casing sliding sleeve in the casing tool string;

[0146] During the production phase, the sleeve switching tool in the tubing tool string is used to open or close the mechanical switch type casing sleeve, and the in-pipe packer in the tubing tool string is used to perform in-pipe plugging, and the interlayer plugging is performed based on the tubing tool string and the casing tool string.

[0147] The above-mentioned system and method of the present invention are simple to implement and reliable in function. They can effectively prevent casing damage, protect casing strings and wellhead devices, and prevent top water from flowing downward. Water layer pretreatment can seal the water layer in advance to prevent downward flow. The thermal recovery casing head is not affected by high temperature, has reliable sealing, and has the characteristics of retractable threaded sealing. It is not only suitable for prestressed construction, but also allows the oil layer casing to rise, thereby protecting the upper casing string and wellhead device of the oil well. The thermal recovery casing has good thermal stability. It can be used in the oil layer section of the super-heavy oil block with more gas injection rounds and severe sand production to increase the casing strength and further prevent casing damage. The thermal compensator can effectively alleviate the thermal stress changes of the casing string in the local well section and reduce casing damage. The mechanical switch-type casing sliding sleeve cooperates with the matching isolation pipe string, and the casing can be connected inside and outside without perforating and drilling plugging operations. It is used to control top water flowing downward and realize interlayer plugging. The prestressed casing anchor is used for prestressed completion, which effectively prevents casing damage in the whole well and wellhead rise. The cement ring is injected with high temperature resistant cement slurry, which has the characteristics of high temperature resistance, slight expansion, good toughness and low cost, and basically meets the requirements of steam injection thermal recovery wells. The deformation buffer and reinforcement tools between the cement ring and the casing play the role of buffering deformation, reinforcing isolation, and preventing damage to the cement ring and casing and water leakage.

[0148] Obviously, various changes and modifications may be made to the present invention by those skilled in the art without departing from the spirit and scope of the present invention. The present disclosure is not limited to the precise structure described above and shown in the accompanying drawings, and various changes and modifications may be made without departing from the scope thereof. The scope of the present disclosure is limited only by the appended claims. Thus, if these changes and modifications of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these changes and modifications.

Claims

1. A system for preventing and controlling underwater channeling and casing damage at the top of a heavy oil thermal recovery well. It is characterized in that include: Water layer plugging tools, casing tool strings and tubing tool strings; Among them, the water layer plugging tool is used to perform open hole pretreatment of the water layer during the drilling stage to seal the water layer; the casing tool string is used to prevent casing deformation and reinforce the cement ring during the completion stage; the oil pipe tool string is used to perform interlayer sealing after top water channeling during the production stage.

2. The system according to claim 1, It is characterized in that The water layer plugging tool comprises: a first central tube, a power supply assembly, a first sealing assembly and an adjustment assembly respectively sleeved on the outer side of the central tube, an unsealing cylinder and a reversing mechanism located inside the first central tube, and a protective tube assembly fixedly connected to the lower end of the unsealing cylinder; The two ends of the power supply assembly and the adjustment assembly limit the first sealing assembly, the limiting cylinder of the adjustment assembly is fixed on the first central tube; the lower protective tube of the protective tube assembly is threadedly connected with the limiting cylinder; the limiting block of the reversing mechanism is fixed on the unsealing cylinder; The power supply assembly is used to act on the first sealing assembly to seal the first sealing assembly; the reversing mechanism is used to adjust the position of the sealing ball in the unsealing cylinder so that the plugging agent can seal the formation through the protective tube assembly; the unsealing cylinder is pressed to move downward to act on the reversing mechanism to drive the protective tube assembly and the adjusting assembly to move downward, so that the first sealing assembly is unsealed.

3. The system according to claim 2, It is characterized in that The power supply assembly comprises: a hydraulic cylinder, a first piston cylinder, a first wedge ring, a first locking ring, a first retaining ring and a first shear pin; Among them, the hydraulic cylinder is sleeved on the outer side of the first center tube and is threadedly connected to the upper end of the first center tube; the first piston cylinder is sleeved between the first center tube and the hydraulic cylinder; the first wedge ring and the first locking ring are respectively located between the hydraulic cylinder and the first piston cylinder, the first locking ring abuts against the lower end of the first wedge ring and bites with the first piston cylinder to limit the first piston cylinder; the first retaining ring is sleeved on the outer side of the first piston cylinder, abuts against the first locking ring, and is threadedly connected to the hydraulic cylinder; the first shear pin passes through the hydraulic cylinder and the first retaining ring respectively and is connected to the first piston cylinder; the lower end of the first piston is adjacent to the first sealing assembly.

4. The system according to claim 3, It is characterized in that The inner surface of the first locking ring is provided with engaging teeth for engaging with the first piston.

5. The system according to claim 3, It is characterized in that The power supply assembly further includes: the first piston ring located between the lower end of the first piston cylinder and the first sealing assembly; The first piston ring is connected to the lower end of the first piston cylinder.

6. The system according to claim 2, It is characterized in that The first sealing assembly comprises: a first rubber sleeve sleeve, a first sealing rubber sleeve, and a first spacer ring; one of the first rubber sleeve sleeves is located between the first sealing rubber sleeve and the first piston ring of the power supply assembly, and one of the first rubber sleeve sleeves is located between the first sealing rubber sleeve and the first adjusting ring of the adjusting assembly; the first spacer ring is located between the two first sealing rubber sleeves; The adjustment assembly comprises: a first adjustment ring, a limiting cylinder and a second shear pin; the first adjustment ring abuts against the first rubber tube sheath; the limiting cylinder is fixed to the first central tube through the second shear pin; the first adjustment ring is threadedly connected to the limiting cylinder, so as to adjust the distance between the power supply assembly and the first sealing assembly by adjusting the position of the first adjustment ring; and / or, The protective tube assembly includes: a lower protective tube, a protective tube shoe and a third shear pin; the inner side of the lower protective tube is sleeved on the unsealing tube and fixed by the third shear pin; the protective tube shoe is threadedly connected to the lower end of the lower protective tube, and a plurality of flow holes are opened on the protective tube shoe.

7. The system according to claim 6, It is characterized in that The adjustment assembly further includes: a limiting ring located between the limiting cylinder and the first center tube, the limiting ring being threadedly connected to the lower end of the first center tube and being used to limit the stroke of the limiting cylinder.

8. The system according to claim 2, It is characterized in that The reversing mechanism comprises: a reversing cylinder, a limiting block, a limiting pin and an elastic component; The reversing cylinder is sleeved inside the unsealing cylinder, and a first reversing groove is opened on the surface of the reversing cylinder; the limit block is fixed on the unsealing cylinder, one end of the limit pin is fixed on the limit block, and the other end is located in the first reversing groove; the elastic component is sleeved on the unsealing cylinder, one end of the bottom is on the unsealing cylinder, and the other end is abutted against the limit block; Under the action of the wellhead pressure and the elastic component, the limiting pin slides in the first reversing groove, so that the reversing cylinder opens or closes the flow hole on the unsealing cylinder.

9. The system according to claim 8, It is characterized in that The reversing mechanism further comprises: a bearing assembly sleeved on the outside of the reversing cylinder; The bearing assembly comprises: a bearing, an upper bearing retaining ring and a lower bearing retaining ring; The elastic component comprises: an elastic member, an upper retaining ring of the elastic member and a lower retaining ring of the elastic member; The limit block, the upper retaining ring of the elastic member, the upper retaining ring of the bearing, the bearing, the lower retaining ring of the bearing, the elastic member and the lower retaining ring of the elastic member are abutted in sequence, and the lower retaining ring of the elastic member is threadedly connected to the unsealing cylinder.

10. The system according to any one of claims 2 to 9, It is characterized in that The water layer plugging tool further includes: a first upper joint, which is sleeved on the outer side of the upper end of the first central pipe and threadedly connected to the first central pipe; the first upper joint is used to connect the water layer plugging tool to a drill pipe.

11. The system according to claim 1, It is characterized in that The casing tool string includes: casing, at least two thermal compensators, casing anchors, or at least one deformation buffer tool, at least one cement ring reinforcement tool, and at least one mechanical switch type casing sliding sleeve; The thermal compensator, the deformation buffer tool, the cement ring reinforcement tool, the mechanical switch type casing sliding sleeve, the thermal compensator and the casing anchor are connected in sequence through the casing; The buffer rubber tube of the deformation buffer tool is used to abut against the cementing cement ring to isolate the cementing cement ring from the casing; The cement ring reinforcement tool is used to reinforce the cement ring of the cementing; The mechanical switch type casing sliding sleeve is used to connect the inside and outside of the casing tool string.

12. The system according to claim 11, It is characterized in that The deformation buffer tool comprises: a second upper joint, a second center tube, a vulcanized rubber ring, a second rubber tube sheath and a buffer rubber tube; Among them, the second upper joint is threadedly connected to the upper part of the second center tube for external casing; the outer side of the second center tube is sequentially sleeved with a vulcanized rubber ring, a second rubber tube sheath, a buffer rubber tube, a second rubber tube sheath and a vulcanized rubber ring; the vulcanized rubber ring and the second center tube are vulcanized.

13. The system according to claim 11, It is characterized in that The cement ring reinforcement tool comprises: a third upper joint, a third center pipe, a first lower joint, and a piston cylinder, a second piston ring, a second sealing assembly, a second adjusting ring, which are sequentially sleeved on the outside of the third center pipe, a second piston cylinder, a second wedge ring, a second locking ring, a second retaining ring, and a fourth shear pin located between the third center pipe and the piston cylinder; The third upper joint, the third central pipe and the first lower joint are threadedly connected in sequence; The piston cylinder and the third center tube are threadedly connected, and the chamber between the piston cylinder and the third center tube is connected through the flow hole on the third center tube; the second piston cylinder is located between the third center tube and the piston cylinder; the second wedge ring is inserted between the second piston cylinder and the piston cylinder to limit the filling of the second piston cylinder; the second locking ring abuts against the second wedge ring and bites with the second piston cylinder to limit the second piston cylinder; the second retaining ring is adjacent to the second locking ring and is threadedly connected to the piston cylinder to limit the second locking ring; the fourth shear pin passes through the piston cylinder and the second retaining ring and is connected to the second piston cylinder; the lower end of the second piston cylinder is connected to the second piston ring; Under the pressure of fluid injected at the wellhead, the high-pressure fluid squeezes the second piston cylinder to shear off the fourth shear pin, and drives the second piston ring to squeeze the second sealing assembly to achieve the second sealing rubber cylinder in the second sealing assembly squeezing the cementing cement ring and thus reinforcing the cementing cement ring.

14. The system according to claim 13, It is characterized in that The second sealing assembly comprises: a third rubber sleeve sheath, a second sealing rubber sleeve, a third rubber sleeve sheath, a second spacer ring, a third rubber sleeve sheath, a second sealing rubber sleeve, and a third rubber sleeve sheath which are sequentially sleeved on the outside of the third central tube; The upper third rubber sleeve sleeve abuts against the second piston ring, and the lower third rubber sleeve sleeve abuts against the second adjustment ring.

15. The system according to claim 11, It is characterized in that The mechanical switch type sleeve sliding sleeve comprises: a fourth upper joint, a sealing cylinder, a positioning cylinder and a second lower joint which are threadedly connected in sequence, and a switch cylinder located inside the sealing cylinder and the positioning cylinder, wherein the upper and lower ends of the switch cylinder are limited by the fourth upper joint and the second lower joint; The sealing cylinder is provided with a plurality of first sealing holes, and the first sealing holes are used to be filled with anti-fouling fillers; The inner side of the positioning cylinder is provided with an upper clamping groove and a lower clamping groove; the inner side of the switch cylinder is provided with a switch clamping groove, the lower part of the switch cylinder is a cage-like structure, and the outer side of the lower part of the switch cylinder is provided with a positioning protrusion; The sleeve switch tool of the tubing tool string cooperates with the switch slot so that under the action of external force, the cage structure of the switch barrel contracts to push the positioning protrusion from the upper slot to the lower slot to open the first sealing hole.

16. The system according to claim 1, It is characterized in that The tubing tool string comprises: an oil pipe, a sleeve switch tool, a sealing nipple, an in-pipe packer and a sealing seat, which are threaded in sequence; The sleeve switch tool is used to open the mechanical switch type sleeve in the sleeve tool string to inject anti-fouling filler; The sealing nipple is provided with a second sealing hole matching the first sealing hole on the sealing cylinder of the mechanical switch type casing sliding sleeve; The in-pipe packer is used to perform in-pipe sealing on the casing tool string; When the in-pipe packer is set in the casing tool string, the plugging material injected from the oil pipe enters the barrier layer through the second sealing hole and the first sealing hole in sequence to achieve the blocking of the barrier layer.

17. The system according to claim 16, It is characterized in that The sliding sleeve switch tool comprises: a fifth upper joint, a fourth center tube, a first upper limit sleeve, a first righting seat, a first righting block, a first righting spring and a first lower limit sleeve; The fifth upper joint is threadedly connected to the fourth center pipe, the upper portion of the fifth upper joint is connected to the oil pipe, and the lower portion of the fourth center pipe is connected to the sealing nipple; The first straightening seat is sleeved on the outside of the fourth center tube, the first upper limit sleeve and the first lower limit sleeve are sleeved on the outside of the fourth center tube and the first straightening seat, and are threadedly connected with the first straightening seat, so as to limit the first straightening seat through the fifth upper joint and the sealing nipple; The first straightening seat is provided with a first straightening groove for accommodating the first straightening block and the first straightening spring on the outer side, and the first straightening block is provided with a first spring groove for accommodating the first straightening spring on the inner side. The first straightening block presses the first straightening spring to be installed in the first straightening groove, and both ends of the first straightening block are limited by the first upper limit sleeve and the first lower limit sleeve. The first straightening block is used to be embedded in the switch slot on the switch cylinder of the mechanical switch type sleeve sliding sleeve.

18. The system according to claim 16, It is characterized in that The in-pipe packer comprises: a sixth upper joint, a fifth center pipe, a third sealing assembly, a third adjusting ring, a limit sleeve, a sixth center pipe, a slip assembly, a straightening assembly and a reversing assembly; The sixth upper joint is threadedly connected to the fifth center tube, the third sealing assembly, the third adjusting ring and the limiting sleeve are sleeved on the outside of the fifth center tube, the third adjusting ring is abutted against the lower end of the third sealing assembly; the limiting sleeve is threadedly connected to the third adjusting ring and the vertebral body of the slip assembly respectively; the lower end of the fifth center tube is nested in the vertebral body; The slip assembly, the straightening assembly and the reversing assembly are sequentially sleeved on the outer side of the sixth central tube, a second reversing groove is provided on the outer side of the lower end of the sixth central tube, and the reversing sliding pin of the reversing assembly is located in the second reversing groove; The slip assembly is used to support and seal the in-pipe packer, the straightening assembly is used to straighten the in-pipe packer, and the reversing assembly is used to unseal the in-pipe packer after it is sealed.

19. The system according to claim 18, It is characterized in that The third sealing assembly comprises: a third sealing rubber tube and a third spacer ring, wherein the third spacer ring separates adjacent third sealing rubber tubes; The slip assembly comprises: a vertebral body, a slip, a slip seat and a slip spring; wherein the vertebral body is sleeved on the outside of the sixth central tube, the slip seat is threadedly connected to the upper end of the second righting seat of the righting assembly, one end of the slip is limited in the groove on the upper part of the slip seat, and the slip spring is respectively connected to the slip and the sixth central tube to limit the slip; The righting assembly comprises: a second upper limit sleeve, a second righting seat, a second righting block, a second righting spring and a second lower limit sleeve; wherein, the second upper limit sleeve and the second lower limit sleeve are arranged on the outer sides of the second righting seat and the sixth center tube, and are threadedly connected with the second righting seat; the outer side of the second righting seat is provided with a second righting groove for accommodating the second righting block and the second righting spring, the inner side of the second righting block is provided with a second spring groove for accommodating the second righting spring, the second righting block squeezes the second righting spring to be installed in the second righting groove, and the two ends of the second righting block are limited by the second upper limit sleeve and the second lower limit sleeve; and / or, The reversing assembly is located between the sixth center tube and the second lower limit sleeve, and the reversing assembly includes: a reversing sliding pin and a reversing sliding ring; the reversing sliding ring is connected to the inner side of the second lower limit sleeve, and one end of the reversing sliding pin is connected to the reversing sliding ring.

20. A method for preventing underwater channeling and casing damage in a heavy oil thermal recovery well. It is characterized in that include: Use water layer plugging tools to pre-treat the water layer during the drilling stage to plug the water layer; During the completion phase, deformation buffer tools and / or cement ring reinforcement tools in the casing tool string are used to prevent casing deformation and / or reinforce cement rings; and the casing tool string is connected to the inside and outside based on a mechanical switch-type casing sliding sleeve in the casing tool string; During the production phase, the sleeve switch tool in the tubing tool string is used to open or close the mechanical switch type casing sleeve, and the tubing is plugged in the tubing based on the in-tubing packer in the tubing tool string, and the interlayer is plugged based on the tubing tool string and the casing tool string.

Images