Controllable sitting hanging device for drilling liner hanger

Abstract

The invention relates to a downhole tool, in particular to a controllable seat hanging device for a drilling liner hanger, which comprises a seat hanging central pipe, a balance unit I and a movable sealing pipe, a balance unit sleeves the seat hanging central pipe, and a first ring cavity III and a second ring cavity IV are formed between the seat hanging central pipe and the balance unit; the movable sealing pipe is divided into an upper pipe section and a lower pipe section through a ball seat in the movable sealing pipe; when the ball is not thrown, the upper pipe section is communicated with the lower pipe section, the upper pipe section is communicated with the first annular cavity III, the lower pipe section is communicated with the second annular cavity IV, and the balance unit I is kept still under the action force in two opposite directions; after a ball is thrown, the upper pipe section and the lower pipe section are cut off, the acting force generated by the first annular cavity III on the balance unit I is larger than that generated by the second annular cavity IV on the balance unit I, and the balance unit I acts in the axial direction so that the slips can be opened to achieve sitting hanging. The hydraulic drilling liner hanger has the beneficial effect that in the process of descending into a well, the hydraulic drilling liner hanger cannot be hung in advance even if the well is blocked by impurities.

Description

Technical Field

[0001] The invention relates to the technical field of downhole tools in oil and gas development, in particular to a controllable sitting and hanging device for a tail pipe hanger. Background Art

[0002] In the process of oil and gas production, the liner hanger is a commonly used downhole tool, which is generally divided into mechanical, hydraulic, and mechanical-hydraulic double-acting types; among them, the hydraulic type is a relatively light-weight application method. The working principle of the hydraulic liner hanger is to start the liner hanger hydraulic cylinder by holding the pressure in the pipe, and the hydraulic cylinder pushes the suspension mechanism to achieve hanging.

[0003] Common hydraulic tail hanger such as Figure 10-12 As shown, a sleeve is arranged outside the center tube and connected to the sleeve by shear nails, and a certain annular cavity is formed between the sleeve and the casing; a movable tube is inserted in the center tube, and a ball seat is arranged somewhere on the casing under the tail tube hanger. If it is necessary to hang the liner hanger on the well wall (the inner wall of the barrel of the well wall): a. lower the liner hanger pipe string to the designed well depth with the drilling tool; b. drop a ball from the front eye, and let the ball fall on the ball seat under the action of gravity, so that the ball blocks the ball seat - that is, the front eye of the liner is blocked, so the movable tube begins to be pressurized, and the large pressure liquid formed by the pressure will enter the annular cavity between the sleeve and the casing through the small hole on the center tube, so the pressure liquid generates an axial force on the sleeve in the annular cavity, so that the sleeve moves axially; since a slip is provided at the end of the sleeve, and a hanging cone is provided outside the center tube, a conical groove is opened on the hanging cone, but when the slip is stuck in the conical groove, the slip continues to move axially with the sleeve, so the slip will be stretched (opened), so the slip is stuck on the upper casing, and the hanging is achieved.

[0004] With the advancement of drilling technology, during the liner cementing process of deep and ultra-deep wells, the hydraulic liner hanger often circulates drilling fluid midway before it reaches the designed well depth due to problems such as difficulty in lowering the liner and well control safety. Excessive pump start pressure during circulation or sudden blockage of the annulus during circulation will cause the pressure inside the pipe to be higher than the pressure outside the pipe, cutting off the shear pins for seating and causing the liner hanger to sit prematurely. Summary of the invention

[0005] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a controllable seating device for a liner hanger to solve the problem that the hydraulic liner hanger may be seated prematurely due to the pump circulating drilling fluid during the wellbore process. Through the corresponding structural design, the hydraulic liner hanger will not be seated prematurely even if the pressure inside the pipe is higher than the pressure outside the pipe during the wellbore process.

[0006] The object of the present invention is achieved through the following technical solutions: A controllable sitting and hanging device for a liner hanger, comprising a sitting and hanging center tube, a balancing unit I, and a movable sealing tube;

[0007] The center tube of the seat is provided with a balancing unit I on the outside and the two are fixed by shear nails A, and the end of the balancing unit I is provided with a slip; a seat cone is fixedly provided on the outer cylindrical surface of the center tube of the seat, and a tapered groove matching the slip is opened on the seat cone; the balancing unit I can move in the axial direction, and when the balancing unit I moves in the axial direction, the slip can be inserted into the tapered groove and opened;

[0008] The outer cylindrical surface of the center tube is provided with a first outer ring convexity and a second outer ring convexity, and the balancing unit I is a sleeve and the inner walls of both ends of the sleeve are provided with a first inner ring convexity and a second inner ring convexity respectively;

[0009] A first annular cavity III is formed between the outer cylindrical surface of the center tube, the inner wall of the sleeve, the first outer annular convexity, and the first inner annular convexity, and a first through hole is opened on the wall of the center tube corresponding to the first annular cavity III;

[0010] A second annular cavity IV is formed between the outer cylindrical surface of the center tube, the inner wall of the sleeve, the second outer annular convexity, and the second inner annular convexity; a second through hole is opened on the wall of the center tube corresponding to the second annular cavity IV;

[0011] A ball seat is arranged in the movable sealing tube. Along the direction of going down the well: the pipe section of the movable sealing tube located above the ball seat is called the upper pipe section, and the pipe section of the movable sealing tube located below the ball seat is called the lower pipe section;

[0012] The movable sealing tube is inserted into the center tube of the seat and forms a ring column interval between the two. The ball seat sleeve is provided with a plurality of leather sleeves, which divide the ring column interval into a plurality of annular cavity sections along the axial direction. A first hole A and a second hole B are opened on the wall of the movable sealing tube.

[0013] The inlet end of the first channel A is located at the inner wall of the upper pipe section, and the outlet end of the first channel A is located at the outer wall of a certain annular cavity section, so that the cavity of the upper pipe section-the first channel A-the corresponding annular cavity section-the first through hole-the first annular cavity III are connected;

[0014] The inlet end of the second channel B is located at the inner wall of the lower pipe section, and the outlet end of the second channel B is located at the outer wall of a certain annular cavity section, so that the tube cavity of the lower pipe section-the second channel B-the corresponding annular cavity section-the second through hole-the second annular cavity IV are connected.

[0015] As a preferred technical solution of the present application, the balancing unit I comprises a sitting cylinder sleeve and a balancing cylinder sleeve; along the downhole direction, the lower end of the sitting cylinder sleeve is threadedly connected with the balancing cylinder sleeve; the upper inner wall of the sitting cylinder sleeve has a first inner ring convex A, and the lower inner wall of the balancing cylinder sleeve has a second inner ring convex B. Along the downhole direction, a slip is provided at the upper end of the sitting cylinder sleeve.

[0016] As a preferred technical solution of the present application, the first inner ring bulge A, the second inner ring bulge B, the first outer ring bulge A, and the second outer ring bulge B are all provided with corresponding annular sealing rings.

[0017] As a preferred technical solution of the present application, there are two or more balancing units I arranged on the outer casing of the central tube of the suspension.

[0018] As the preferred technical solution of the present application, the central tube sleeve of the sitting and hanging is provided with two balancing units I. Along the downhole direction: the balancing units I located at the upper and lower positions are respectively referred to as the upper balancing unit and the lower balancing unit. The lower port of the movable sealing tube is close to the lower balancing unit. Three leather sleeves are provided on the movable sealing tube sleeve. Along the downhole direction, the three leather sleeves are respectively referred to as the first leather sleeve, the second leather sleeve, and the third leather sleeve. Along the downhole direction, the first leather sleeve is located below the ball seat and is also located between the first annular cavity III of the upper balancing unit and the second annular cavity IV of the upper balancing unit; along the downhole direction, the second leather sleeve is located between the second annular cavity IV of the upper balancing unit and the first annular cavity III of the lower balancing unit; along the downhole direction, the third leather sleeve is located between the first annular cavity III of the lower balancing unit and the fourth annular cavity IV of the lower balancing unit. When the ball is not dropped and the downhole pressure is blocked, the pressure liquid in the movable sealing tube: part of the pressure liquid flows into the first annular cavity III of the upper balancing unit through the corresponding first channel A-the corresponding first through hole-and flows into the second annular cavity IV of the upper balancing unit through the corresponding second channel B-the corresponding second through hole; part of the pressure liquid flows into the first annular cavity III of the lower balancing unit through the corresponding first channel A-the corresponding first through hole, and part of the fracturing flows into the second annular cavity IV of the lower balancing unit through the corresponding second channel B and / or the lower port of the movable sealing tube-the corresponding second through hole. After the ball is dropped, the pressure liquid in the movable sealing tube: part of the pressure liquid flows into the first annular cavity III of the upper balancing unit through the corresponding first channel A-the corresponding first through hole, and part of the pressure liquid flows into the first annular cavity III of the lower balancing unit through the corresponding first channel A-the corresponding first through hole; at this time, the second annular cavity IV of the upper balancing unit is connected with the liquid in the well, and the second annular cavity IV of the lower balancing unit is connected with the liquid in the well.

[0019] As a preferred technical solution of the present application, in the movable sealing tube, the upper end of the lower tube section has a stepped hole A that is larger at the top and smaller at the bottom. A collision ring is placed on the stepped hole A, and the upper end of the collision ring has multiple raised tips. The upper outer sleeve of the collision ring is provided with a support ring and the two are connected via shear nails B. The upper end of the support ring extends out of the upper end of the collision ring, and a ball seat is placed on the upper end of the support ring. The ball seat is a glass seat with a center hole. When the ball is thrown from the movable sealing tube, the ball falls on the ball seat, thereby blocking the center hole, and the balance unit I is moved axially by guiding the corresponding pressure liquid, thereby realizing the hanging of the tail hanger. When the tail hanger is hung, the pressure of the pressure liquid in the movable sealing tube is increased, so that the shear nails B are cut, so that the support ring moves downward relative to the collision ring, so that the ball seat hits the raised tip of the collision ring, and the ball seat is broken.

[0020] As the preferred technical solution of the present application, the upper end of the center tube of the seat is connected with a straightening inverted joint through threads, and the straightening inverted joint also has a stepped hole B that is larger at the top and smaller at the bottom, and the inner wall of the large diameter hole of the stepped hole B is provided with an internal thread. The upper end of the movable sealing tube is fixedly connected with an inverted sliding tube, and the outer cylindrical surface of the inverted sliding tube is in the shape of a stepped shaft that is smaller at the top and larger at the bottom. A threaded sleeve is sleeved on the cylindrical surface of the stepped shaft with a large diameter, and the two can slide and cooperate with each other along the axial direction through a spline-like structure, and the outer cylindrical surface of the threaded sleeve is provided with an external thread. When the movable sealing tube rotates, it can drive the threaded sleeve to rotate, so that the external thread of the threaded sleeve is connected to the internal thread of the straightening inverted joint, so that the movable sealing tube is installed on the center tube of the seat.

[0021] As a preferred technical solution of the present application, the central pipe for hanging is formed by connecting multiple pipe sections II through a straightening double female joint. The lower end of the movable sealing pipe is connected with a core sealing pipe section.

[0022] The present invention has the following advantages:

[0023] The new tail pipe hanger uses an independent double-cylinder controllable sitting and hanging device, which controls the movement of the sitting and hanging cylinder sleeve through the two cavities inside the sitting and hanging cylinder sleeve and the balance cylinder sleeve. Before throwing the ball and holding the pressure, the two cavities are connected through the inner pipe to make the pressure equal. No matter why the pressure in the pipe changes due to any factors, the upward force generated by the inner cavity of the sitting and hanging cylinder sleeve and the downward force generated by the inner cavity of the balance cylinder sleeve will achieve a balance between the two forces and no movement will occur. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a structural schematic diagram of the present invention;

[0025] Figure 2 It is a schematic diagram of the structure after sectioning of the present invention;

[0026] Figure 3 It is a schematic diagram of the structure of the present invention at the balancing unit I;

[0027] Figure 4 for Figure 3 A schematic diagram of the structure of a part of the pipe section;

[0028] Figure 5 It is a part of the pipe section of the movable sealing pipe;

[0029] Figure 6 for Figure 5 A schematic diagram of the structure of a part of the pipe section;

[0030] Figure 7 It is a structural schematic diagram of a part of the pipe section of the center pipe for hanging;

[0031] Figure 8 for Figure 7 A schematic diagram of the structure of a part of the pipe section;

[0032] Fig. 9 It is a schematic diagram of the structure between the upright undercut joint, the threaded sleeve and the undercut sliding pipe at the upper end of the present invention;

[0033] Fig.10 It is a schematic diagram of the sitting and hanging structure of a common tail hanger;

[0034] Fig.11 for Fig.10 A magnified view of the middle AA;

[0035] Fig.12 for Fig.10 Enlarged view of the middle BB;

[0036] In the figure: 1. Center tube for seating; 2. Cylinder sleeve for seating; 3. Balancing cylinder sleeve; 4. Slips; 5. Double female joint for centering; 7. Cylinder body for seating; 8. Threaded sleeve; 9. Inverted joint for centering; 10. Movable sealing tube; 11. Inverted sliding tube; 13. Seat core tube section; 14. Ball seat; 15. Support ring; 16. Strike ring; 18. Leather cover. DETAILED DESCRIPTION

[0037] The present invention is further described below in conjunction with the accompanying drawings, but the protection scope of the present invention is not limited to the following description.

[0038] It should be noted that the directions or positional relationships indicated by "left", "right", etc. are based on the directions or positional relationships shown in the accompanying drawings, or are the directions or positional relationships in which the inventive product is usually placed when in use, or are the directions or positional relationships commonly understood by those skilled in the art. Such terms are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on the present invention.

[0039] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features and technical solutions in the embodiments may be combined with each other.

[0040] like Figures 1 to 9 As shown, a controllable sitting and hanging device for a liner hanger comprises a sitting and hanging center tube 1, a balancing unit I, and a movable sealing tube 10;

[0041] A balancing unit I is provided on the outer sleeve of the center pipe 1 and the two are fixed by shear nails A, and a slip 4 is provided at the end of the balancing unit I; a hanging cone 7 is fixedly provided on the outer cylindrical surface of the center pipe 1, and when the whole device is placed vertically, the hanging cone 7 is located above the slip 4, and a tapered groove matched with the slip 4 is opened on the hanging cone 7; if the balancing unit I can move axially (i.e. upward), the slip 4 is pushed upward to allow the slip 4 to be inserted into the tapered groove and thus opened, and the slip 4 is stuck on the inner wall of the casing at the well wall after being stuck (which is a conventional principle).

[0042] The core of this solution lies in the design of the balancing unit I, which will be further described below.

[0043] See also Figure 4 , Figure 8 The outer cylindrical surface of the center tube 1 has a first outer ring convexity and a second outer ring convexity, and the balancing unit I is a sleeve and the inner walls of both ends of the sleeve have a first inner ring convexity and a second inner ring convexity respectively. The outer cylindrical surface of the center tube 1, the inner wall of the sleeve, the first outer ring convexity and the first inner ring convexity form a first ring cavity III, and the outer cylindrical surface of the center tube 1, the inner wall of the sleeve, the second outer ring convexity and the second inner ring convex form a second ring cavity IV;

[0044] See also Figure 4 , Figure 8 In addition, a first through hole is opened on the wall of the center tube 1 corresponding to the first annular cavity III, and a second through hole is opened on the wall of the center tube 1 corresponding to the second annular cavity IV;

[0045] See also Figure 6 A ball seat 14 is provided in the movable sealing tube 10. In the direction of going down the well, the pipe section of the movable sealing tube 10 located above the ball seat 14 is called the upper pipe section, and the pipe section of the movable sealing tube 10 located below the ball seat 14 is called the lower pipe section;

[0046] See also Figure 3 , Figure 4 The movable sealing tube 10 is inserted into the center tube 1 of the seat and forms a ring column interval between the two. A plurality of leather sleeves 18 are provided on the ball seat 14. The plurality of leather sleeves 18 divide the ring column interval into a plurality of annular cavity segments along the axial direction.

[0047] See also Figure 3 , Figure 4, a first channel A and a second channel B are opened on the tube wall of the movable sealing tube 10; the inlet end of the first channel A is located at the inner wall of the upper tube section, and the outlet end of the first channel A is located at the outer wall of a certain annular cavity section, so that the tube cavity of the upper tube section-the first channel A-the corresponding annular cavity section-the first through hole-the first annular cavity III are connected; in addition, the inlet end of the second channel B is located at the inner wall of the lower tube section, and the outlet end of the second channel B is located at the outer wall of a certain annular cavity section, so that the tube cavity of the lower tube section-the second channel B-the corresponding annular cavity section-the second through hole-the second annular cavity IV are connected;

[0048] In addition, in order to ensure the sealing performance, corresponding annular sealing rings are provided at the first inner ring convexity A, the second inner ring convexity B, the first outer ring convexity A, and the second outer ring convexity B.

[0049] It should be noted that during the entire process of lowering the tail tube hanger into the well, the tail tube hanger is placed in a casing that is intended to be fixed to the well wall. The hanging of the tail tube hanger is essentially to allow the cava 4 to engage with the wall of the casing at a certain position. In the process of lowering the tail tube hanger into the well, it is necessary to introduce pressure liquid into the movable sealing tube 10. After the pressure liquid is ejected from the lower end of the tail tube hanger, it is ejected outward through the annular cavity between the outer wall of the tail tube hanger (the hanging center tube 1) and the inner wall of the casing - thereby carrying out some impurities in the well (there will be impurities in the well itself - such as gravel, soil, etc.). However, there is a problem that if impurities block the lower end of the tail tube hanger, or impurities block the annular cavity between the outer wall of the tail tube hanger and the inner wall of the casing, and pressure liquid is continuously introduced into the movable sealing tube 10, it will cause pressure buildup in the well, which will cause the pressure of the movable sealing tube 10 to rise. In conventional design structures such as Fig.11 As shown, after the pressure is held, Fig.11 When the pressure in the middle tube increases, the pressure fluid pushes Fig.11 The outermost sleeve moves upward, and the upward movement of the sleeve will push the slips upward, so that the slips are opened by the force, and after the slips are opened, they are buckled with the inner wall of the sleeve to achieve early seating.

[0050] In this scheme, the structural design of the balance unit I is such that when the well is blocked due to impurities, for a certain balance unit I: a part of the pressure liquid flows into the first annular cavity III of the upper balance unit through the corresponding first channel A-the corresponding first through hole, thereby pushing the balance unit I upward; and a part of the pressure liquid flows into the second annular cavity IV of the upper balance unit through the corresponding second channel B-the corresponding second through hole, thereby pushing the balance unit downward. Since the pressure of the pressure liquid entering the first annular cavity III and the pressure liquid entering the second annular cavity IV are equal in magnitude and opposite in direction, when the pressure is blocked, the balance unit I will not move, and there will be no premature hanging.

[0051] The structure of the balance unit I is further explained below.

[0052] Specifically, see Figure 2 The balancing unit I includes a sitting cylinder sleeve 2 and a balancing cylinder sleeve 3; along the downhole direction, the lower end of the sitting cylinder sleeve 2 is threadedly connected with the balancing cylinder sleeve 3; the upper inner wall of the sitting cylinder sleeve 2 is provided with a first inner ring convex A, and the lower inner wall of the balancing cylinder sleeve 3 is provided with a second inner ring convex B. Along the downhole direction, a slip 4 is provided at the upper end of the sitting cylinder sleeve 2.

[0053] The specific structure of the installation of the balancing unit I on the central tube 1 is exemplified below.

[0054] It should be noted that there are two or more balancing units I arranged outside the central tube 1 .

[0055] For example, two balancing units I are disposed on the outer sleeve of the central pipe 1. Along the downhole direction, the balancing units I located at the upper and lower positions are respectively called the upper balancing unit and the lower balancing unit;

[0056] In addition, the lower end of the movable sealing tube 10 is close to the lower balancing unit;

[0057] Three leather sleeves 18 are provided on the movable sealing tube 10, and the three leather sleeves 18 are respectively called the first leather sleeve, the second leather sleeve, and the third leather sleeve along the downhole direction. Along the downhole direction, the first leather sleeve is located below the ball seat 14 and is also located between the first annular cavity III of the upper balancing unit and the second annular cavity IV of the upper balancing unit; along the downhole direction, the second leather sleeve is located between the second annular cavity IV of the upper balancing unit and the first annular cavity III of the lower balancing unit; along the downhole direction, the third leather sleeve is located between the first annular cavity III of the lower balancing unit and the fourth annular cavity IV of the lower balancing unit;

[0058] During operation: when the ball is not dropped and the downhole pressure is held, the pressure liquid in the movable sealing tube 10: a part of the pressure liquid flows into the first annular cavity III of the upper balancing unit through the corresponding first channel A-the corresponding first through hole-and flows into the second annular cavity IV of the upper balancing unit through the corresponding second channel B-the corresponding second through hole; a part of the pressure liquid flows into the first annular cavity III of the lower balancing unit through the corresponding first channel A-the corresponding first through hole-and flows into the second annular cavity IV of the lower balancing unit through the corresponding second channel B and / or the lower port of the movable sealing tube 10-the corresponding second through hole;

[0059] During operation, after the ball is dropped, the pressure liquid in the movable sealing tube 10: part of the pressure liquid flows into the first annular cavity III of the upper balancing unit through the corresponding first channel A-the corresponding first through hole-and part of the pressure liquid flows into the first annular cavity III of the lower balancing unit through the corresponding first channel A-the corresponding first through hole; at this time, the second annular cavity IV of the upper balancing unit is connected with the liquid in the well, and the second annular cavity IV of the lower balancing unit is connected with the liquid in the well.

[0060] The structure of the ball seat 14 will be further described below.

[0061] Specifically, see Figure 4 and Figure 6 In the movable sealing tube 10, the upper end of the lower tube section is provided with a stepped hole A which is larger at the upper end and smaller at the lower end. A collision ring 16 is placed on the stepped hole A, and the upper end of the collision ring 16 has a plurality of protruding tips; a support ring 15 is provided on the upper outer sleeve of the collision ring 16, and the two are connected via shear nails B, and the upper end of the support ring 15 extends out of the upper end of the collision ring 16, and a ball seat 14 is placed on the upper end of the support ring 15; and the ball seat 14 is a glass seat, and a center hole is opened on the ball seat 14, and the hole of the center hole is a ball arc shape adapted to the ball - so that the center hole can be well blocked when the ball contacts the center hole;

[0062] During operation, when a ball is dropped from the movable sealing tube 10, the ball falls on the ball seat 14, thereby blocking the center hole, and guiding the corresponding pressure fluid to realize the axial movement of the balance unit I, thereby realizing the sitting of the tail hanger. When the tail hanger is sat, the pressure of the pressure fluid in the movable sealing tube 10 is increased, so that the shear nail B is cut, and then the support ring 15 moves downward relative to the impact ring 16, so that the ball seat 14 hits the protruding tip of the impact ring 16, and the ball seat 14 breaks.

[0063] The structure of the center pipe 1 and the structure of the movable sealing pipe 10 will be further described below.

[0064] See also Figure 5 The center pipe 1 is formed by connecting multiple pipe sections II through the straightening double female joint 5. Of course, adjacent pipe sections II can also be connected through the hanging cone 7, which also has the same straightening protrusion as the straightening double female joint 5. The hanging cone 7 plays the role of the straightening double female joint 5; of course, the hanging cone 7 is provided with a conical groove for the arch slip 4 to open / stretch.

[0065] The movable sealing tube 10 comprises an upper tube section and a lower tube section, and a seat sealing core tube section 13 is threadedly connected to the lower end of the lower tube section.

[0066] Furthermore, the installation of the movable sealing tube 10 on the center tube 1 is described.

[0067] See Figure Figure 2and Fig. 9 The upper end of the center tube 1 is connected with a straightening reverse buckle joint 9 through threads. The straightening reverse buckle joint 9 also has a stepped hole B with a large upper part and a small lower part. The inner wall of the large diameter hole of the stepped hole B has an internal thread. The upper end of the movable sealing tube 10 is fixedly connected with a reverse buckle sliding tube 11. The outer cylindrical surface of the reverse buckle sliding tube 11 is a stepped shaft with a small upper part and a large lower part. A threaded sleeve 8 is sleeved on the cylindrical surface of the stepped shaft with a large diameter. The two can slide with each other along the axial direction through a spline-like structure. The outer cylindrical surface of the threaded sleeve 8 has an external thread.

[0068] During operation, when the movable sealing tube 10 rotates, the threaded sleeve 8 can be driven to rotate, so that the external thread of the threaded sleeve 8 is connected with the internal thread of the uprighting undercut joint 9, so that the movable sealing tube 10 is installed on the sitting center tube 1.

[0069] The above embodiments only express preferred implementation modes, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present invention. It should be pointed out that, for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention.

Claims

1. A controllable sitting and hanging device for a liner hanger, characterized in that: It comprises a center tube (1), a balancing unit I, and a movable sealing tube (10); The center tube (1) of the seat is provided with a balancing unit I on its outer sleeve and the two are fixed by shear nails A, and the end of the balancing unit I is provided with a slip (4); a seat cone (7) is fixedly provided on the outer cylindrical surface of the center tube (1), and a taper groove matching the slip (4) is provided on the seat cone (7); the balancing unit I can move in the axial direction, and when the balancing unit I moves in the axial direction, the slip (4) can be inserted into the taper groove and open; The outer cylindrical surface of the center tube (1) is provided with a first outer ring convexity and a second outer ring convexity, and the balancing unit I is a sleeve and the inner walls of both ends of the sleeve are provided with a first inner ring convexity and a second inner ring convexity respectively; A first annular cavity III is formed between the outer cylindrical surface of the center tube (1), the inner wall of the sleeve, the first outer annular convexity and the first inner annular convexity, and a first through hole is opened on the wall of the center tube (1) corresponding to the first annular cavity III; A second annular cavity IV is formed between the outer cylindrical surface of the center tube (1), the inner wall of the sleeve, the second outer annular convexity, and the second inner annular convexity; a second through hole is opened on the wall of the center tube (1) corresponding to the second annular cavity IV; A ball seat (14) is arranged inside the movable sealing tube (10). In the direction of going down the well, the pipe section of the movable sealing tube (10) located above the ball seat (14) is called an upper pipe section, and the pipe section of the movable sealing tube (10) located below the ball seat (14) is called a lower pipe section. The movable sealing tube (10) is inserted into the center tube (1) of the seat and forms a ring column spacing between the two. A plurality of leather sleeves (18) are sleeved on the ball seat (14). The plurality of leather sleeves (18) divide the ring column spacing into a plurality of annular cavity sections along the axial direction. A first hole A and a second hole B are opened on the wall of the movable sealing tube (10); The inlet end of the first channel A is located at the inner wall of the upper pipe section, and the outlet end of the first channel A is located at the outer wall of a certain annular cavity section, so that the cavity of the upper pipe section-the first channel A-the corresponding annular cavity section-the first through hole-the first annular cavity III are connected; The inlet end of the second channel B is located at the inner wall of the lower pipe section, and the outlet end of the second channel B is located at the outer wall of a certain annular cavity section, so that the tube cavity of the lower pipe section-the second channel B-the corresponding annular cavity section-the second through hole-the second annular cavity IV are connected.

2. The controllable sitting device for a liner hanger according to claim 1, characterized in that: The balancing unit I comprises a hanging cylinder sleeve (2) and a balancing cylinder sleeve (3); Along the downhole direction, the lower end of the sitting cylinder sleeve (2) is connected to a balancing cylinder sleeve (3) via threads; the upper inner wall of the sitting cylinder sleeve (2) is provided with a first inner ring protrusion A, and the lower inner wall of the balancing cylinder sleeve (3) is provided with a second inner ring protrusion B; Along the downhole direction, a slip (4) is arranged at the upper end of the sitting cylinder sleeve (2).

3. The controllable sitting device for a liner hanger according to claim 2, characterized in that: The first inner ring convexity A, the second inner ring convexity B, the first outer ring convexity A, and the second outer ring convexity B are all provided with corresponding annular sealing rings.

4. A controllable sitting device for a liner hanger according to any one of claims 1 to 3, characterized in that: The number of balancing units I arranged on the outer surface of the central sitting tube (1) is two or more.

5. The controllable sitting device for a liner hanger according to claim 4, characterized in that: The central tube (1) is provided with two balancing units I on its outer sleeve. Along the downhole direction, the balancing units I located at the upper and lower positions are respectively called the upper balancing unit and the lower balancing unit. The lower end of the movable sealing tube (10) is close to the lower balancing unit; Three leather covers (18) are provided on the movable sealing tube (10), and the three leather covers (18) are respectively called the first leather cover, the second leather cover, and the third leather cover along the downhole direction; Along the direction of going down the well, the first leather sleeve is located below the ball seat (14) and between the first annular cavity III of the upper balancing unit and the second annular cavity IV of the upper balancing unit; along the direction of going down the well, the second leather sleeve is located between the second annular cavity IV of the upper balancing unit and the first annular cavity III of the lower balancing unit; along the direction of going down the well, the third leather sleeve is located between the first annular cavity III of the lower balancing unit and the fourth annular cavity IV of the lower balancing unit; When the ball is not dropped and the downhole pressure is held, the pressure liquid in the movable sealing tube (10): part of the pressure liquid flows into the first annular cavity III of the upper balancing unit through the corresponding first channel A-the corresponding first through hole-and flows into the second annular cavity IV of the upper balancing unit through the corresponding second channel B-the corresponding second through hole; part of the pressure liquid flows into the first annular cavity III of the lower balancing unit through the corresponding first channel A-the corresponding first through hole-and flows into the second annular cavity IV of the lower balancing unit through the corresponding second channel B and / or the lower port of the movable sealing tube (10)-the corresponding second through hole; After the ball is dropped, the pressure liquid in the movable sealing tube (10): part of the pressure liquid flows into the first annular cavity III of the upper balancing unit through the corresponding first channel A-the corresponding first through hole-and part of the pressure liquid flows into the first annular cavity III of the lower balancing unit through the corresponding first channel A-the corresponding first through hole; at this time, the second annular cavity IV of the upper balancing unit is connected with the liquid in the well, and the second annular cavity IV of the lower balancing unit is connected with the liquid in the well.

6. The controllable sitting device for a liner hanger according to claim 5, characterized in that: In the movable sealing tube (10), the upper end of the lower tube section has a stepped hole A which is larger at the top and smaller at the bottom. A striker ring (16) is placed on the stepped hole A. The upper end of the striker ring (16) has a plurality of protruding tips. The upper outer sleeve of the impact ring (16) is provided with a support ring (15) and the two are connected via shear nails B. The upper end of the support ring (15) extends out of the upper end of the impact ring (16), and a ball seat (14) is placed on the upper end of the support ring (15); The ball seat (14) is a glass seat with a central hole; When a ball is dropped from the movable sealing tube (10), the ball falls on the ball seat (14), thereby blocking the central hole, and guiding the corresponding pressure fluid to realize the axial movement of the balance unit I, thereby realizing the sitting of the tail hanger; When the tail hanger is hung, the pressure of the pressure liquid in the movable sealing tube (10) is increased to cut the shear nail B, so that the support ring (15) moves downward relative to the impact ring (16), and the ball seat (14) hits the protruding tip of the impact ring (16), so that the ball seat (14) breaks.

7. The controllable sitting device for a liner hanger according to claim 6, characterized in that: The upper end of the center pipe (1) is threadedly connected to a centering undercut joint (9), which also has a stepped hole B that is larger at the top and smaller at the bottom, and an internal thread is formed on the inner wall of the large diameter hole of the stepped hole B; The upper end of the movable sealing tube (10) is fixedly connected to a reverse-locking sliding tube (11), the outer cylindrical surface of the reverse-locking sliding tube (11) is in the shape of a stepped shaft with a small top and a large bottom, a threaded sleeve (8) is sleeved on the cylindrical surface of the stepped shaft with a large diameter, and the two can slide with each other in the axial direction through a spline-like structure, and the outer cylindrical surface of the threaded sleeve (8) is provided with an external thread; When the movable sealing tube (10) rotates, it can drive the threaded sleeve (8) to rotate, so that the external thread of the threaded sleeve (8) is connected with the internal thread of the uprighting undercut joint (9), so that the movable sealing tube (10) is installed on the center tube (1).

8. The controllable sitting device for a liner hanger according to claim 1, characterized in that: The center pipe (1) is formed by connecting a plurality of pipe sections II by butting them together through a straightening double female joint (5); The lower end of the movable sealing tube (10) is connected to a core sealing tube section (13).

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