Packer for preventing setting deviation and assembly method thereof

Abstract

The invention relates to a packer for preventing setting deviation and an assembling method thereof. The packer is provided with an upper pipe connector, a central pipe and a slip assembly, the central pipe is arranged in the packer, the slip assembly is arranged in the middle area of the packer and arranged outside the central pipe, the upper portion of the slip assembly is connected to a limiting connecting cylinder through an upper cone, an unpacking sleeve is arranged above the limiting connecting cylinder, and the lower portion of the slip assembly is connected to the lower portion of the upper cone. The upper pipe joint is connected with the unpacking sleeve in a matched mode, the lower portion of the slip assembly is connected to the rubber sleeve assembly through the lower cone, the setting sleeve is arranged below the rubber sleeve assembly, and the lower pipe joint is arranged below the setting sleeve; the slip assembly comprises a slip, a plurality of slip petals are arranged at the two ends of the slip respectively, a plurality of slip grooves with opposite opening directions are formed in the slip petals at the two ends of the slip respectively, and setting deviation prevention columns are arranged in the slip grooves.

Description

Technical Field

[0001] The present application relates to a packer for preventing deviation of the setting seal and an assembly method thereof, and is applicable to the technical field of downhole plugging tools. Background Art

[0002] A packer is a downhole sealing tool used to isolate the upper formation, drilling fluid and test layer during the drill pipe test. When it is necessary to seal the annular space of the oil pipe, oil and gas well casing or open hole wall, connect the packer to the downhole tubing, and after it reaches the designed depth, use hydraulic drive and other means to expand the sealing components on the packer to seal the oil casing annulus. The stability of the seal and the continuity of the seal are necessary conditions for qualified isolation. However, the prerequisite for achieving the above necessary conditions is that the fullness of the cava is sufficient. The shortcomings of the existing technology are mainly manifested in the lack of a guide design for the cava, which leads to the deviation of the seal and insufficient anchoring force, which can easily cause the packer to move and unseal, resulting in failure of the isolation.

[0003] More specifically, the slips of conventional packers mainly change their diameters on the inclined surface in the direction of the upper and lower cone axes, so that the part of the slips that contacts the cone also changes its diameter as the axis moves, gradually expanding and sticking to the inner wall of the casing. During the entire expansion process, the slips are only subjected to the reverse force from the surface of the cone, that is, to ensure that the slips are fully and stably expanded, it is necessary to ensure that the reverse force borne by each petal is the same, and at the same time, the size state, external environment, and internal quality of the materials of the connecting parts of each petal of the slip are the same. The above conditions can only be achieved under theoretical conditions, so it is inevitable that the setting is not ideal. Summary of the invention

[0004] The purpose of this application is to design a sealer and an assembly method thereof that prevents the sealer from being dislocated, which fully considers the downhole operating conditions and solves the problem of premature sealing of the sealer before operation through structural optimization; it can also solve the common problem of uneven expansion of the slips during operation, resulting in loose sealing and incomplete sealing, thereby greatly improving the success rate and stability of the sealing and greatly reducing the time and economic costs of the operation.

[0005] The present application relates to a packer for preventing displacement of the sealing member, which comprises an upper pipe joint, a center pipe and a cava assembly, wherein the center pipe is arranged inside the packer, the cava assembly is arranged in the middle area of ​​the packer and outside the center pipe, the upper part of the cava assembly is connected to a limiting connecting cylinder via an upper cone, a release sleeve is arranged above the limiting connecting cylinder, the upper pipe joint is cooperatively connected with the release sleeve, the lower part of the cava assembly is connected to a rubber cylinder assembly via a lower cone, a sealing sleeve is arranged below the rubber cylinder assembly, and a lower pipe joint is arranged below the sealing sleeve; the cava assembly comprises a cava, a plurality of cava petals are respectively arranged at both ends of the cava, the cava petals at both ends of the cava are respectively provided with a plurality of cava grooves with opposite opening directions, and a column for preventing displacement of the sealing member is arranged in the cava groove.

[0006] In which, the lower end of the upper pipe joint is provided with a mounting groove, and an unsealing seat is provided in the mounting groove, and the unsealing seat is cooperatively connected with the center tube, and the unsealing sleeve is arranged on the outer side of the lower end of the upper pipe joint, and a fixing pin is provided between the unsealing sleeve and the upper pipe joint, and the unsealing sleeve and the unsealing seat are connected by an unsealing pin; a limiting cylinder is provided between the unsealing sleeve and the limiting connecting cylinder, and a part of the limiting cylinder is arranged on the outside of the center tube, and the other part of the limiting cylinder is exposed between the unsealing sleeve and the limiting connecting cylinder; a locking block and a limiting seat are also provided inside the limiting connecting cylinder, and the limiting seat and the center tube are connected by a locking block, and the limiting seat is connected to the end of the upper cone.

[0007] The slip assembly comprises a slip upper cover and a slip lower cover, the slip upper cover and the slip lower cover are respectively arranged on both sides of the slip, the slip upper cover and the slip lower cover are provided with guide grooves, and guide pins are arranged in the guide grooves; the anti-setting offset column is assembled on the upper cone and the lower cone, and the slip upper cover and the upper cone, as well as the slip lower cover and the lower cone are connected by setting pins; a setting piston is provided below the rubber cylinder assembly, and the setting piston is installed On the center tube, the lower end of the center tube is connected to a lower center tube, the setting sleeve is arranged on the outside of the setting piston and the lower center tube, and the end of the lower center tube is connected to the lower pipe joint; a part of the lower pipe joint is inserted into the setting sleeve, a locking ring hanger is provided on the outside of the lower center tube, and a locking ring seat is also provided between the lower center tube and the setting sleeve, and the locking ring seat and the locking ring hanger are locked by a locking ring to realize a fastening connection between the lower center tube and the setting sleeve.

[0008] Wherein, the expansion force F of the packer T Calculate according to the following empirical formula:

[0009] F T =MAX[FP1 , F P2 ]

[0010]

[0011] In the formula, F P1 is the radial breaking force of the slip connection, F P2 is the tangential fracture force of the slip connection, σ L1 is the tensile strength of the slip material, L K is the slip length, L L is the length of the left dividing slot, L R is the length of the right dividing slot, L Z D is the total length of the slips along the conical surface of the upper cone and the lower cone. KW is the maximum outer diameter of the slip, D KN is the maximum inner diameter of the slip, S is the number of slip petals, θ is the angle of each slip petal, γ is the cone angle of the slip body, and R1 is the radius of the slip petal.

[0012] The present application also relates to a method for assembling a packer for preventing setting deviation, comprising the following steps:

[0013] (1) Take the upper pipe joint and connect it to the unsealing seat, and connect the central pipe to the lower end of the unsealing seat;

[0014] (2) Install the unsealing sleeve, connect it to the upper pipe joint and fix it through a fixing pin, and connect the unsealing sleeve to the unsealing seat through the unsealing pin;

[0015] (3) A limiting tube is further installed on the outside of the central tube, and the limiting tube is connected to the end of the unsealing sleeve;

[0016] (4) Install the locking block, the limiting seat and the limiting connecting tube in sequence, wherein the locking block is installed between the limiting seat and the center tube, and the limiting seat is connected to the end of the upper cone;

[0017] (5) After the upper slip end cover is connected with the upper cone, it is installed on the center pipe;

[0018] (6) Connect the slip upper cover to the slip hanging end cover;

[0019] (7) Install the anti-setting offset column on the upper cone, then fix the slip cover and the upper cone with the setting pins, and finally install the guide pins;

[0020] (8) Install the slips so that the slip grooves of the slips correspond to the anti-setting offset columns;

[0021] (9) Install the slip lower cover, the setting pins on the slip lower cover and the lower cone in the same manner as in step 8;

[0022] (10) Install the transition ring, rubber cylinder and setting piston on the center tube in sequence;

[0023] (11) Connect the lock ring to the lock ring hook, then to the lock ring seat, and then install it on the center pipe;

[0024] (12) Connect the setting sleeve to the outside of the lower center pipe, and finally connect the lower pipe joint to the end of the setting sleeve and tighten it. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 is a schematic diagram of the packer of the present application.

[0026] Figure 2 is a cross-sectional view of the packer of the present application.

[0027] Figure 3 It is a schematic diagram of the left end portion of the packer of the present application.

[0028] Figure 4 It is a sectional view of the left end portion of the packer of the present application.

[0029] Figure 5 It is a schematic diagram of the middle part of the packer of the present application.

[0030] Figure 6 It is a cross-sectional view of the middle part of the packer of the present application.

[0031] Figure 7 It is a schematic diagram of the right end portion of the packer of the present application.

[0032] Figure 8 It is a sectional view of the right end portion of the packer of the present application.

[0033] Fig. 9 It is a cross-sectional view of the slip of the present application. DETAILED DESCRIPTION

[0034] In order to make the purpose, technical solutions and advantages of the present application clearer, the embodiments of the present application will be described in detail in conjunction with the accompanying drawings below. It should be noted that, in the absence of conflict, the embodiments in the present application and the features in the embodiments can be arbitrarily combined with each other. The words indicating the orientation in the present application are for the purpose of describing the accompanying drawings and do not constitute any limitation on the scope of protection. As shown in the accompanying drawings, the top of the present application refers to the left side of the drawings, and the bottom refers to the right side of the drawings. For downhole tools, the top refers to the side of the downhole tool close to the wellhead, and the bottom refers to the side of the downhole tool away from the wellhead.

[0035] The purpose of the present application is to provide a packer with improved stability and high success rate of setting. The difference between this packer and the existing packers lies in the upper cover of the slip, the lower cover of the slip and the slip. The design of this packer to prevent the setting deviation is to break the theoretical working environment, change the movement trend of the slip itself through external restrictions, and achieve a more ideal setting. Shown in the drawings of the present application is a single-cava multi-rubber compression packer that prevents the setting deviation, which is mainly used to separate production layer sections, prevent inter-layer cross-flow and interference, separate the well-killing fluid and the production fluid, and retain the function of the packer fluid.

[0036] like Figure 1 As shown, the packer of the present application includes upper pipe joint, fixing pin, sealing ring, unsealing seat, unsealing sleeve, unsealing pin, central pipe, limiting tube, locking block, limiting seat, limiting connecting tube, upper cone, slip upper cover, slip, slip lower cover, lower cone, transition ring, rubber tube, spacer ring, setting piston, lower central pipe, locking ring seat, locking ring, locking ring head, setting sleeve, lower pipe joint and other components. The design of the packer of the present application fully considers the requirements of well operation. After the setting is completed, the anchoring force is strong, the operation is stable, and the sealing effect is good.

[0037] According to the packer of the present application, there are provided a slip assembly and a center pipe, the center pipe is arranged inside the packer, and the slip assembly is arranged outside the center pipe in the middle area of ​​the packer. The upper part of the slip assembly is connected to the limit connection tube 11 through the upper cone 12, and the upper part of the limit connection tube 11 is provided with a release sleeve 5. The upper part of the release sleeve 5 is provided with an upper pipe joint 1, and the lower part of the slip assembly is connected to the rubber sleeve assembly through the lower cone 21. The rubber sleeve assembly is connected to the setting sleeve 28, and the setting sleeve 28 is provided with a setting piston 27, and the end of the setting sleeve 28 is connected to the lower pipe joint 33. The lower end of the center pipe 7 is provided with a lower center pipe 29, and the center pipe 7 and the lower center pipe 29 can be connected by threads, and the lower center pipe 29 is arranged in the setting sleeve 28.

[0038] like Figure 1-8As shown, a mounting groove is provided on the inner side of the lower end of the upper pipe joint 1, and the unsealing seat 4 is inserted into the mounting groove and connected to the lower end of the upper pipe joint 1, and the unsealing seat 4 is matched and connected with the center pipe 7 and fastened by screws. An unsealing sleeve 5 is threadedly connected to the outer side of the lower end of the upper pipe joint 1, and a fixing pin 2 is also provided between the unsealing sleeve 5 and the upper pipe joint 1, and the unsealing sleeve 5 and the unsealing seat 4 are connected by an unsealing pin 6. A limiting cylinder 8 can be provided between the unsealing sleeve 5 and the limiting connecting cylinder 11, and part of the limiting cylinder 8 is arranged outside the center pipe 7, and part of the limiting cylinder 8 is exposed between the unsealing sleeve 5 and the limiting connecting cylinder 11. A sealing ring 3 can be provided at the outer side of the upper pipe joint 1, the outer side of the unsealing seat 4, the outer side of the center pipe 7, the outer side of the limiting cylinder 8, etc., to seal the packer. A locking block 9 and a limiting seat 10 may also be provided inside the limiting connection tube 11 , wherein the limiting seat 10 and the central tube 7 are connected via the locking block 9 , and the limiting seat 10 is threadedly connected to the end of the upper cone 12 .

[0039] The slip assembly includes a slip 16, a slip upper cover 14 and a slip lower cover 19, wherein the slip upper cover 14 and the slip lower cover 19 are respectively arranged on the upper and lower sides of the slip 16. The slip upper cover 14 is threadedly connected to the slip hanging end cover 13, and the slip upper cover 14 and the upper cone 12 are connected by a setting pin 15. The slip upper cover 14 is provided with a guide groove, and a guide pin 18 is provided in the guide groove, and the guide groove can guide the guide pin 18 to move inside it. A plurality of slip flaps are respectively provided at both ends of the slip 16, and the slip flaps at both ends of the slip 16 are respectively provided with a plurality of slip grooves with opposite opening directions, that is, the left slip groove on the upper side of the slip 16 opens toward the direction of the upper cone 12, and the right slip groove on the lower side of the slip 16 opens toward the direction of the lower cone 21. An anti-setting offset column 17 is provided in the slip groove, and the anti-setting offset column 17 can be assembled on the upper cone 12 and the lower cone 21. The anti-seating displacement column 17 can be, for example, a guide pin, which is used to realize the sliding of the fixed position of the slip to achieve uniform opening, ensure that the sealing force is uniform, and provide a better working basis for the later downhole fracturing construction. Similarly, a guide groove is also provided on the slip lower cover 19, and a guide pin 18 is provided in the guide groove. The guide groove can guide the guide pin 18 to move inside it. The slip lower cover 19 and the lower cone 21 are connected by the sealing pin 20. The lower side of the lower cone 21 is connected to a transition ring 22, and the lower side of the transition ring 22 is connected to a rubber cylinder assembly in turn. The rubber cylinder assembly of the present application can include three rubber cylinders arranged in sequence, namely a first rubber cylinder 23, a second rubber cylinder 24 and a third rubber cylinder 26, and a spacer ring 25 can be provided between the three rubber cylinders.

[0040] A setting piston 27 is provided below the third rubber cylinder 26, which is the lowest rubber cylinder, and the setting piston 27 is installed on the center tube 7. The lower end of the setting piston 27 is connected to the lower center tube 29, and a setting sleeve 28 is provided on the outer side of the setting piston 27 and the lower center tube 29. A lower pipe joint 33 is connected to the end of the lower center tube 29, and a part of the lower pipe joint 33 is inserted into the setting sleeve 28. A locking ring hanger 31 is provided on the outer side of the lower center tube 29, and a locking ring seat 30 is further provided between the lower center tube 29 and the setting sleeve 28. The locking ring seat 30 and the locking ring hanger 31 are locked by a locking ring 32, thereby realizing a tight connection between the lower center tube 29 and the setting sleeve 28.

[0041] According to the present application, a packer for preventing setting deviation is assembled as follows:

[0042] (1) Take the upper pipe joint 1 and connect it to the unsealing seat 4, connect the central pipe 7 to the lower end of the unsealing seat 4, and tighten it with screws;

[0043] (2) Install the unsealing sleeve 5, so that it is connected to the upper pipe joint 1 through threads and fixed through the fixing pin 2, and the unsealing sleeve 5 is connected to the unsealing seat 4 through the unsealing pin 6;

[0044] (3) A limiting tube 8 is further installed on the outer side of the central tube 7, and the limiting tube 8 is threadedly connected to the end of the unsealing sleeve 5;

[0045] (4) Then install the locking block 9, the limiting seat 10 and the limiting connecting tube 11 in sequence;

[0046] (5) After the upper slip end cover 13 is matched with the upper cone 12, it is installed on the central tube 7;

[0047] (6) Connect the slip cover 14 to the slip end cover 13 by threading. If the sealing pin 15 is not installed first, the subsequent accessories cannot be installed.

[0048] (7) Install the anti-setting offset column 17 on the upper cone 12 to prevent setting. After completion, use the setting pin 15 to fix the slip cover 14 and the upper cone 12, and finally install the guide pin 18;

[0049] (8) Install the slips 16 so that the slip grooves of the slips 16 correspond to the anti-setting offset columns 17;

[0050] (9) Install the slip lower cover 19, the setting pin 20, and the lower cone 21 in the same manner as step 8;

[0051] (10) Then, the transition ring 22, the first rubber cylinder 23, the spacer ring 25, the second rubber cylinder 24, the spacer ring 25, the third rubber cylinder 26, and the setting piston 27 are sequentially installed on the central tube 7;

[0052] (11) Connect the lock ring 32 to the lock ring hanger 31, then connect it to the lock ring seat 30, and finally install it on the center pipe 29;

[0053] (12) Finally, install the lower center pipe 29 to the end of the center pipe 7, and then connect the sealing sleeve 28 to the outside of the lower center pipe 29. Finally, connect the lower pipe joint 33 to the end of the sealing sleeve 28 and fasten it with a pin.

[0054] When setting is required, the upper part of the packer is connected to the oil pipe, and hydraulic pressure is applied through the oil in the oil pipe. The hydraulic pressure acts on the setting piston 27 through the pressure guide hole of the center pipe. When the pressure reaches a certain level, the setting pin 20 located at the lower cone 21 and the lower cover 19 of the slip is sheared off, and the setting force is transmitted to the upper cover 14 of the slip through the slip 16, and the setting pin 15 located at the upper cone 12 is sheared off. The oil pressure continues to increase, and the slip petals of the slip 16 expand along the anti-setting offset column 17, and the first rubber cylinder 23, the second rubber cylinder 24, and the third rubber cylinder 26 also expand continuously, and finally close to the inner wall of the casing, the annular space of the oil casing is sealed, and the setting is completed.

[0055] When unsealing is required, the joint is lifted, and when the unsealing pin 6 is sheared off and fails, as the unsealing seat 4 and the unsealing sleeve 5 are pulled out, the upper cone 12 loses its unilateral fixation, and the contraction force generated when the rubber tube rebounds pushes the upper and lower cones to move. When the rubber tube rebounds, the sealing effect disappears immediately.

[0056] According to the packer of the present application, there is also a structure to prevent premature setting, which can effectively prevent the packer from setting when it is not required for work, such as manufacturing, transportation, handling, operation and installation. Once the packer is set at an unneeded time, it will cause the packer to be scrapped, which means that the operation has failed in the well, and it will generate higher operating costs. The above-mentioned structure to prevent premature setting includes a setting pin 15, and there is a structure design of a slip cover 14 and a slip cover 19 on both sides of the slip 16, with the slip 16 in the middle. When the middle component is accidentally subjected to force to trigger the setting action, the setting pin 15 connects the cone and the slip cover and cannot move without being sheared off; when the external accidental force triggers the setting action, it will not trigger the setting similar to the previous situation. The difference between the setting caused by the external accidental force is that even if the setting pin is accidentally sheared off, the slip cover 14, the slip cover 19 and the end faces of the slip 16 are all overlapped, that is, they will be pressed against each other when subjected to force and cannot move. In summary, the packer is designed to operate normally and will only be triggered to set when the oil pressure reaches a certain level.

[0057] The biggest difference between the slips of the packer of the present application and the conventional slip design is that an anti-seating offset column 17 is added. The anti-seating offset column 17 is located on the upper cone and the lower cone in the three-dimensional assembly relationship, between the slip grooves of each petal of the packer slip. The principle that the anti-seating offset column 17 can prevent the setting offset is the guiding effect during the movement of the cone. The guiding effect is that when the lower cone 21 moves, the anti-seating offset column 17 on it also moves relatively. Since the height of the anti-seating offset column 17 is higher than the inclined surface where the slip 16 contacts the cone, the anti-seating offset column 17 is always located between the petals of the slip 16 and cannot be dislodged or rotated. In the process of the cone pushing the slip 16 to move, due to the uneven force on each petal of the slip, problems that may occur include: the slip petals are not separated or rotated, and when they are attached to the inner wall of the casing, uneven slip petals of different sizes are presented, resulting in failure of setting. Due to the existence of the anti-seating deviation column 17, when the cava petals are not separated, the anti-seating deviation column 17 can impact the connection between the cava petals and shear the connection between the petals; when the cava petals rotate, since the anti-seating deviation column 17 is provided at the upper and lower ends of the cava 16, no matter whether the cava petals rotate clockwise or counterclockwise, they will always be blocked by the anti-seating deviation column 17 and cannot rotate.

[0058] When designing the packer of the present application, the expansion force of the slips is an important design parameter, which can be used to determine the size of the external load that prevents the packer from setting prematurely, and facilitates the protection of the packer during use. T It can be calculated according to the following empirical formula:

[0059] F T =MAX[F P1 ,F P2 ]

[0060]

[0061] In the formula, F P1 is the radial breaking force of the slip connection, F P2 is the tangential fracture force of the slip connection, σ L1 is the tensile strength of the slip material, L K is the total length of the slip, L L is the length of the left cava groove, L R is the length of the right slip groove, L Z D is the total length of the slips along the conical surface of the upper cone and the lower cone. KW is the maximum outer diameter of the slip, D KN is the maximum inner diameter of the slip, S is the number of slip petals, θ is the angle of each slip petal, γ is the cone angle of the slip body, and R1 is Fig. 9The taper angle described in the present application is the angle between the extended side of the slip and the longitudinal center axis of the bridge plug in the cross-sectional view.

[0062] Table 1 Example of bridge plug design

[0063]

[0064]

[0065] Although the implementation methods disclosed in this application are as above, the contents described are only implementation methods adopted for facilitating the understanding of this application, and are not intended to limit this application. Any technician in the technical field to which this application belongs can make any modifications and changes in the form and details of implementation without departing from the spirit and scope disclosed in this application, but the scope of patent protection of this application shall still be based on the scope defined in the attached claims.

Claims

1. A packer for preventing setting deviation, characterized in that: An upper pipe joint, a lower pipe joint, a center pipe and a slip assembly are provided, wherein the center pipe is arranged inside the packer, the slip assembly is arranged outside the center pipe, the upper part of the slip assembly is connected to a limit connection cylinder through an upper cone, an unsealing sleeve is provided above the limit connection cylinder, the upper pipe joint is cooperatively connected with the unsealing sleeve, the lower part of the slip assembly is connected to a rubber cylinder assembly through a lower cone, a setting sleeve is provided below the rubber cylinder assembly, and the lower pipe joint is provided below the setting sleeve; The slip assembly comprises a slip, and a plurality of slip petals are respectively provided at both ends of the slip, and the slip petals at both ends of the slip are respectively provided with a plurality of slip grooves with opposite opening directions, and an anti-seating deviation column is provided in the slip groove.

2. The packer according to claim 1, characterized in that: The lower end of the upper pipe joint is provided with a mounting groove, and an unsealing seat is provided in the mounting groove. The unsealing seat is cooperatively connected with the center pipe. The unsealing sleeve is arranged on the outer side of the lower end of the upper pipe joint. A fixing pin is provided between the unsealing sleeve and the upper pipe joint, and the unsealing sleeve and the unsealing seat are connected via the unsealing pin.

3. The packer according to claim 2, characterized in that: A limiting cylinder is provided between the unsealing sleeve and the limiting connecting cylinder, a part of the limiting cylinder is arranged outside the central tube, and another part of the limiting cylinder is exposed between the unsealing sleeve and the limiting connecting cylinder.

4. The packer according to claim 3, characterized in that: A locking block and a limiting seat are also provided inside the limiting connection cylinder. The limiting seat and the central tube are connected via the locking block, and the limiting seat is connected to the end of the upper cone.

5. The packer according to any one of claims 1 to 4, characterized in that: The slip assembly comprises a slip upper cover and a slip lower cover, wherein the slip upper cover and the slip lower cover are respectively arranged on both sides of the slip, and guide grooves are arranged on the slip upper cover and the slip lower cover, and guide pins are arranged in the guide grooves.

6. The packer according to claim 5, characterized in that: The anti-setting offset column is assembled on the upper cone and the lower cone, and the slip upper cover and the upper cone, as well as the slip lower cover and the lower cone are connected via setting pins.

7. The packer according to any one of claims 1 to 4 and 6, characterized in that: A sealing piston is provided below the rubber cylinder assembly, the sealing piston is installed on the center tube, the lower end of the center tube is connected to the lower center tube, the sealing sleeve is arranged on the outside of the sealing piston and the lower center tube, and the end of the lower center tube is connected to the lower tube joint.

8. The packer according to claim 7, characterized in that: A portion of the lower pipe joint is inserted into the setting sleeve, a locking ring hanger is provided on the outer side of the lower center pipe, and a locking ring seat is also provided between the lower center pipe and the setting sleeve. The locking ring seat and the locking ring hanger are locked by a locking ring to achieve a fastened connection between the lower center pipe and the setting sleeve.

9. The packer according to any one of claims 1 to 4, 6 and 8, characterized in that: The expansion force F of the packer T Calculate according to the following empirical formula: F T =MAX[F P1 ,F P2 ] In the formula, F P1 is the radial breaking force of the slip connection, F P2 is the tangential fracture force of the slip connection, σ L1 is the tensile strength of the slip material, L K is the slip length, L L is the length of the left dividing slot, L R is the length of the right dividing slot, L Z D is the total length of the slips along the conical surface of the upper cone and the lower cone. KW is the maximum outer diameter of the slip, D KN is the maximum inner diameter of the slip, S is the number of slip petals, θ is the angle of each slip petal, γ is the cone angle of the slip body, and R1 is the radius of the slip petal.

10. A method for assembling a packer for preventing setting deviation, comprising the following steps: (1) Take the upper pipe joint and connect it to the unsealing seat, and connect the central pipe to the lower end of the unsealing seat; (2) Install the unsealing sleeve, connect it to the upper pipe joint and fix it through a fixing pin, and connect the unsealing sleeve to the unsealing seat through the unsealing pin; (3) A limiting tube is further installed on the outside of the central tube, and the limiting tube is connected to the end of the unsealing sleeve; (4) Install the locking block, the limiting seat and the limiting connecting tube in sequence, wherein the locking block is installed between the limiting seat and the center tube, and the limiting seat is connected to the end of the upper cone; (5) After the upper slip end cover is connected with the upper cone, it is installed on the center pipe; (6) Connect the slip upper cover to the slip hanging end cover; (7) Install the anti-setting offset column on the upper cone, then fix the slip cover and the upper cone with the setting pins, and finally install the guide pins; (8) Install the slips so that the slip grooves of the slips correspond to the anti-setting offset columns; (9) Install the slip lower cover, the setting pins on the slip lower cover and the lower cone in the same manner as in step 8; (10) Install the transition ring, rubber cylinder and setting piston on the center tube in sequence; (11) Connect the lock ring to the lock ring hook, then to the lock ring seat, and then install it on the center pipe; (12) Connect the setting sleeve to the outside of the lower center pipe, and finally connect the lower pipe joint to the end of the setting sleeve and tighten it.

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