A drill string stabilizer with variable diameter

Abstract

A variable diameter drilling tool stabilizer, the present invention relates to drilling accessory tool technical field. The relationship between the hook and switch ring is: when the hook rises, the locking arm hooks the lower horizontal arm, when the hook continues to rise, the locking arm is ejected under the action of the upper corner and hangs on the upper side of the upper inclined arm of the switch ring, under the action of the compression spring, the locking arm slides downward along the upper inclined arm, at this time the elastic sheet bends, the locking arm slides downward beyond the switch ring, the elastic sheet returns to normal, and the hook returns to the initial position. The beneficial effects of the present invention are: by setting the variable diameter switch assembly on the piston, the pipe string pressure rise can expand the centralizer outward, complete the expansion, and lock the piston and the centralizer at the same time. By throwing the soluble ball again, the piston can be unlocked, the piston falls under the action of the compression spring, the centralizer retracts, and the diameter of the drilling tool stabilizer is reduced. This process can be repeated without frequent tripping and drilling, greatly reducing the drilling cost and improving the drilling efficiency.

Description

Technical Field

[0001] This invention relates to the field of drilling accessory tools technology, and more particularly to a drill string stabilizer with a variable diameter. Background Technology

[0002] During drilling, stabilizers are commonly used to control the wellbore trajectory and prevent well deviation. When traditional drilling tools are affected by formation conditions and drilling technology and cannot follow the predetermined drilling trajectory, the common method is to change the diameter of the downhole stabilizer to increase, stabilize, or decrease the deviation. However, in such cases, the diameter of most existing stabilizers is fixed, which requires frequent tripping and running, greatly increasing drilling costs, reducing drilling efficiency, and affecting drilling operations. Summary of the Invention

[0003] To address the aforementioned problems, the present invention provides a drill string stabilizer with a variable diameter.

[0004] The technical solution provided by this invention is: a drill string stabilizer for drilling with variable diameter, including an upper connector, a central tube connected to the lower part of the upper connector by a threaded seal, a lower connector connected to the lower part of the central tube by a threaded seal, an outer sleeve extending upward from the outer circle of the lower connector, a piston provided between the outer sleeve and the central tube, the piston and the outer sleeve and the central tube being fitted with a sealing ring through a gap, a liquid inlet hole being opened in the central tube below the sealing ring of the piston, and a conical ball seat hole being machined at the bottom of the central tube;

[0005] The upper outer circle of the piston is machined into a conical ring surface, with the larger end of the conical ring surface at the bottom. Three dovetail grooves are opened on the conical ring surface, and the three dovetail grooves are evenly arranged along the outer circle of the piston. Three straightening bars are installed on the conical ring surface of the piston. The inner side of the straightening bar is in conical fit with the conical ring surface. The inner side of the straightening bar extends into a dovetail bar, which slides in fit with the dovetail groove. The straightening bar is sandwiched between the outer sleeve and the upper connector in the axial direction.

[0006] The piston is equipped with three sets of variable diameter switch assemblies. The three sets of variable diameter switch assemblies are located in each dovetail groove. Each set of variable diameter switch assemblies includes two ear plates. The two ear plates are welded to the upper end of the piston. The two ear plates are rotatably connected to the hinge sleeve through a pin. An elastic sheet is fixedly connected to the upper part of the hinge sleeve. A hook is fixedly connected to the upper part of the elastic sheet. A switch ring is welded to the upper part of the hook on the central tube.

[0007] The pin is arranged tangentially along the outer circle of the piston. The hook consists of an upper locking arm, a middle pull arm, and a lower seat plate. The upper part of the locking arm has a rounded corner. The seat plate is connected to the elastic sheet by bolts. The gap between the locking arm and the seat plate is greater than the height of the switch ring. The bottom of the switch ring is a horizontal lower cross arm and the upper part is an upper inclined arm.

[0008] The variable diameter switch assembly also includes a lower positioning post, which is welded to the upper end of the piston. The upper connector has a support post welded to its lower end face. An upper positioning post is welded to the lower side of the support post. The diameter of the upper positioning post is smaller than that of the support post. A compression spring is fitted on the upper positioning post, and the other end of the compression spring is fitted on the lower positioning post.

[0009] The hook and center tube are made of carbon steel, while the switch ring and centering bar are made of stainless steel. The hook is magnetized.

[0010] The structural relationship between the hook and the switch ring is as follows: when the hook rises, the locking arm hooks the lower horizontal arm. When the hook continues to rise, the locking arm pops out under the action of the upper rounded corner and hangs on the upper side of the upper inclined arm of the switch ring. Under the action of the compression spring, the locking arm slides down along the upper inclined arm. At this time, the elastic plate bends, the locking arm slides down past the switch ring, the elastic plate returns to the center, and the hook returns to the initial position.

[0011] A nylon gasket is provided between the straightening bar and the upper connector.

[0012] The upper connector extends downwards with three guide bars, and the gap formed by the three guide bars is fitted with the gap of each straightening bar.

[0013] The straightening bar has a flow groove.

[0014] The beneficial effects of this invention are as follows: By setting a diameter-changing switch assembly on the piston, the invention increases the pressure in the tubing once a soluble ball is dropped, which expands the centralizing bar outward to complete the diameter expansion. At the same time, the piston and centralizing bar are locked. By dropping a soluble ball again, the piston can be unlocked. The piston falls under the action of the compression spring, and the centralizing bar retracts, completing the diameter reduction of the drill string stabilizer. This process can be repeated, eliminating the need for frequent tripping and running of the drill string, which greatly reduces drilling costs and improves drilling efficiency. Attached Figure Description

[0015] Appendix Figure 1 This is a schematic diagram of the structure of the present invention;

[0016] Appendix Figure 2 This is a partial three-dimensional view of the present invention;

[0017] Appendix Figure 3 It is attached Figure 1 CC cross-section;

[0018] Appendix Figure 4 It is attached Figure 1 Enlarged view of point B;

[0019] Appendix Figure 5 It is attached Figure 2 Enlarged view of point A;

[0020] Appendix Figure 6 This is a schematic diagram of the switching ring structure in this invention;

[0021] Appendix Figure 7 This is a schematic diagram of the hook structure in this invention;

[0022] Appendix Figure 8 It is attached Figure 3 A schematic diagram of the piston structure.

[0023] In the diagram, 1-upper connector, 101-guide bar, 2-lower connector, 201-outer sleeve, 3-centering bar, 4-center tube, 5-piston, 501-conical annular surface, 502-dovetail groove, 6-inlet hole, 7-ball seat hole, 8-flow groove, 9-dovetail bar, 10-reducing diameter switch assembly, 11-nylon gasket, 12-ear plate, 13-pin, 14-elastic sheet, 15-hook, 151-locking arm, 152-pull arm, 153-seat plate, 16-switch ring, 161-lower horizontal arm, 162-upper inclined arm, 17-lower positioning post, 18-compression spring, 19-upper positioning post, 20-support post, 21-hinge sleeve. Detailed Implementation

[0024] like Figures 1-7 As shown, a drill string stabilizer with a variable diameter includes an upper connector 1, a central tube 4 with a threaded seal connection at the lower part of the upper connector 1, a lower connector 2 with a threaded seal connection at the lower part of the central tube 4, an outer sleeve 201 extending upward from the outer circle of the lower connector 2, a piston 5 provided between the outer sleeve 201 and the central tube 4, the piston 5 being fitted with the outer sleeve 201 and the central tube 4 through a sealing ring clearance, the central tube 4 having a liquid inlet hole 6 below the sealing ring of the piston 5, and the bottom of the central tube 4 being machined into a conical ball seat hole 7;

[0025] The upper outer circle of piston 5 is machined into a conical annular surface 501, with the larger end of the conical annular surface 501 at the bottom. Three dovetail grooves 502 are opened on the conical annular surface 501 and are evenly arranged along the outer circle of piston 5. Three straightening bars 3 are installed on the conical annular surface 501 of piston 5. The inner side of the straightening bar 3 is in conical fit with the conical annular surface 501. A dovetail bar 9 extends from the inner side of the straightening bar 3 and slides in fit with the dovetail groove 502. The straightening bar 3 is sandwiched between the outer sleeve 201 and the upper connector 1 in the axial direction. The function of the above structure is that when a soluble ball is put into the ball seat hole 7, the pressure in the column increases and the hydraulic pressure enters the piston 5, driving the piston 5 to rise. The straightening bar 3 expands outward under the action of the dovetail groove 502 and the dovetail bar 9. Conversely, when the piston 5 descends, the straightening bar 3 retracts.

[0026] The piston 5 is provided with three sets of variable diameter switch assemblies 10. The three sets of variable diameter switch assemblies 10 are located at each dovetail groove 502. Each set of variable diameter switch assemblies 10 includes two ear plates 12. The two ear plates 12 are welded to the upper end of the piston 5. The two ear plates 12 are rotatably connected to the hinge sleeve 21 through the pin 13. The upper part of the hinge sleeve 21 is fixedly connected to the elastic plate 14. The upper part of the elastic plate 14 is fixedly connected to the hook 15. The central tube 4 has a switch ring 16 welded to the upper part of the hook 15.

[0027] The pin 13 is arranged tangentially along the outer circle of the piston 5. The hook 15 consists of an upper locking arm 151, a middle pull arm 152 and a lower seat plate 153. The upper part of the locking arm 151 is provided with rounded corners. The seat plate 153 is connected to the elastic sheet 14 by bolts. The gap between the locking arm 151 and the seat plate 153 is greater than the height of the switch ring 16. The bottom of the switch ring 16 is a horizontal lower horizontal arm 161 and the upper part is an upper inclined arm 162.

[0028] The variable diameter switch assembly 10 also includes a lower positioning post 17, which is welded to the upper end of the piston 5. The upper connector 1 has a support post 20 welded to its lower end face. An upper positioning post 19 is welded to the lower side of the support post 20. The diameter of the upper positioning post 19 is smaller than that of the support post 20. A compression spring 18 is fitted on the upper positioning post 19. The other end of the compression spring 18 is fitted on the lower positioning post 17.

[0029] Hook 15 and center tube 4 are made of carbon steel, switch ring 16 and straightening bar 3 are made of stainless steel. Hook 15 is magnetized so that there is a magnetic attraction between hook 15 and center tube 4, and hook 15 always moves toward center tube 4.

[0030] The structural relationship between hook 15 and switch ring 16 is as follows: when hook 15 rises, locking arm 151 hooks lower horizontal arm 161. When hook 15 continues to rise, locking arm 151 pops out under the action of the upper rounded corner and hangs on the upper side of upper inclined arm 162 of switch ring 16. Under the action of compression spring 18, locking arm 151 slides down along upper inclined arm 162. At this time, elastic plate 14 bends, locking arm 151 slides down past switch ring 16, elastic plate 14 returns to center, and hook 15 returns to the initial position.

[0031] When it is necessary to increase the outer diameter of the drill stabilizer, a soluble ball is inserted into the tubing. The soluble ball falls onto the ball seat hole 7 and seals it. The tubing is pressurized, and the hydraulic pressure pushes the piston 5 upward through the inlet hole 6. The centering bar 3 expands outward under the action of the dovetail groove 502 and the dovetail bar 9. The hook 15 rises, and the locking arm 151 is hung on the lower cross arm 161 to fix the piston 5 and the centering bar 3, thus completing the outer diameter expansion.

[0032] When it is necessary to retract the outer diameter of the drill string stabilizer, a soluble ball is inserted into the tubing again. The soluble ball lands on the ball seat hole 7 and seals it. The tubing is pressurized by a pulse, and the hydraulic pressure pushes the piston 5 upward again through the inlet hole 6. The hook 15 continues to rise, and the locking arm 151 pops out under the action of the upper rounded corner and hangs on the upper side of the upper inclined arm 162 of the switch ring 16. Under the action of the compression spring 18, the locking arm 151 slides down along the upper inclined arm 162. At this time, the elastic plate 14 bends, and the locking arm 151 slides past the switch ring 16. The elastic plate 14 returns to the center, the hook 15 returns to the initial position, the piston 5 falls back under the action of the compression spring 18, and the centering bar 3 retracts to the initial position, completing the retraction of the outer diameter of the drill string stabilizer.

[0033] This invention provides a diameter-changing switch assembly 10 on piston 5. When a soluble ball is dropped, the pressure inside the tubing increases, causing the centralizing bar 3 to expand outward, thus increasing the diameter. At the same time, piston 5 and centralizing bar 3 are locked. By dropping another soluble ball, piston 5 can be unlocked. Under the action of compression spring 18, piston 5 falls, and centralizing bar 3 retracts, thus reducing the diameter of the drill string stabilizer. This process can be repeated, eliminating the need for frequent tripping and tripping, which greatly reduces drilling costs and improves drilling efficiency.

[0034] A nylon gasket 11 is provided between the straightening bar 3 and the upper connector 1 to reduce the frictional resistance when the straightening bar 3 moves.

[0035] The upper connector 1 extends downwards with three guide bars 101. The gap formed by the three guide bars 101 is fitted with the clearance of each straightening bar 3. The guide bars 101 help resist the torque on the straightening bar 3 and improve its service life.

[0036] The straightening strip 3 has a flow groove 8 to reduce the flow resistance of the drilling mud.

Claims

1. A drill string stabilizer with a variable diameter, comprising an upper connector (1), characterized in that: The upper connector (1) is threaded and sealed to the lower part of the central tube (4), and the lower part of the central tube (4) is threaded and sealed to the lower connector (2). The outer circle of the lower connector (2) extends upward to form an outer sleeve (201). A piston (5) is provided between the outer sleeve (201) and the central tube (4). The piston (5) is fitted with the outer sleeve (201) and the central tube (4) through a sealing ring gap. The central tube (4) has an inlet hole (6) below the sealing ring of the piston (5). The bottom of the central tube (4) is machined into a conical ball seat hole (7). The upper outer circle of the piston (5) is machined into a conical ring surface (501), with the larger end of the conical ring surface (501) at the bottom. Three dovetail grooves (502) are opened on the conical ring surface (501). The three dovetail grooves (502) are evenly arranged along the outer circle of the piston (5). Three straightening bars (3) are installed on the conical ring surface (501) of the piston (5). The inner side of the straightening bar (3) is in conical fit with the conical ring surface (501). A dovetail bar (9) extends from the inner side of the straightening bar (3). The dovetail bar (9) is in sliding fit with the dovetail groove (502). The straightening bar (3) is sandwiched between the outer sleeve (201) and the upper connector (1) in the axial direction. The piston (5) is provided with three sets of variable diameter switch assemblies (10) on the upper part. The three sets of variable diameter switch assemblies (10) are located in each dovetail groove (502) part. Each set of variable diameter switch assembly (10) includes two ear plates (12). The two ear plates (12) are welded to the upper end of the piston (5). The two ear plates (12) are rotatably connected to the hinge sleeve (21) through the pin (13). The upper part of the hinge sleeve (21) is fixedly connected to the elastic plate (14). The upper part of the elastic plate (14) is fixedly connected to the hook (15). The central tube (4) has a switch ring (16) welded on the upper part of the hook (15). The pin (13) is arranged tangentially along the outer circle of the piston (5). The hook (15) consists of an upper locking arm (151), a middle pull arm (152) and a lower seat plate (153). The upper part of the locking arm (151) is provided with rounded corners. The seat plate (153) is connected to the elastic sheet (14) by bolts. The gap between the locking arm (151) and the seat plate (153) is greater than the height of the switch ring (16). The bottom of the switch ring (16) is a horizontal lower horizontal arm (161) and the upper part is an upper inclined arm (162). The variable diameter switch assembly (10) also includes a lower positioning post (17), which is welded to the upper end of the piston (5). The upper connector (1) has a support post (20) welded to its lower end face. An upper positioning post (19) is welded to the lower side of the support post (20). The diameter of the upper positioning post (19) is smaller than that of the support post (20). A compression spring (18) is fitted on the upper positioning post (19). The other end of the compression spring (18) is fitted on the lower positioning post (17). The hook (15) and center tube (4) are made of carbon steel, the switch ring (16) and the straightening bar (3) are made of stainless steel, and the hook (15) is magnetized. The structural relationship between the hook (15) and the switch ring (16) is as follows: when the hook (15) rises, the locking arm (151) hooks the lower horizontal arm (161). When the hook (15) continues to rise, the locking arm (151) pops out under the action of the upper rounded corner and hangs on the upper side of the upper inclined arm (162) of the switch ring (16). Under the action of the compression spring (18), the locking arm (151) slides down along the upper inclined arm (162). At this time, the elastic plate (14) bends, the locking arm (151) slides down past the switch ring (16), the elastic plate (14) returns to the center, and the hook (15) returns to the initial position.

2. The drill string stabilizer with variable diameter according to claim 1, characterized in that: A nylon gasket (11) is provided between the straightening strip (3) and the upper connector (1).

3. A drill string stabilizer with a variable diameter according to claim 1, characterized in that: The upper connector (1) extends downwards with three guide bars (101), and the gap formed by the three guide bars (101) is fitted with each straightening bar (3) with a clearance.

4. A drill string stabilizer with a variable diameter according to claim 1, characterized in that: The straightening bar (3) has an overflow groove (8).

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