Centralizer and centralizing method

Abstract

The present application provides a centralizer and a centralizing method, belonging to the field of petroleum mechanical equipment. The centralizer includes: a body, at least three centralizing slips, a gear and a driving device. At least three centralizing slips are arranged in the body, and one end of at least three centralizing slips is connected to the inner side of the body through a first shaft. The sides of at least three centralizing slips are engaged with the inner surface of the gear sleeved on the body, and the gear is engaged with the driving device. A first through hole is provided at the center of the body for the tubing to be centralized to pass through the first through hole and enter the body. The driving device is used to drive the other ends of at least three centralizing slips to converge towards the first through hole through the gear, so as to centralize the tubing. At least three centralizing slips of the centralizer can centralize the tubing, making the tubing concentric with the wellhead, thus avoiding the problem that the slips of the tubing chuck cannot fall due to the deviation of the tubing from the center of the wellhead and cannot hold the tubing. There is no need to manually centralize the tubing, which saves time and effort, and thus improves the construction efficiency of well workover.

Description

Technical Field

[0001] This application relates to the field of oil and gas mechanical equipment, and particularly relates to a centralizer and a centralizing method. Background Art

[0002] During the workover operation in an oilfield, pulling and running tubing is an essential workover process. However, manual pulling and running tubing is labor-intensive, inefficient, and dangerous. Therefore, mechanical pulling and running tubing has become the main development direction for current pulling and running tubing.

[0003] When mechanically pulling out tubing, generally, the top (coupling end) of the first tubing to be pulled out is lifted by a hook, and then the first tubing is lifted above the wellhead by the hook. Then, the upper part of the second tubing connected to the bottom of the first tubing is clamped by a tubing chuck located at the wellhead. After the first tubing is removed from the top of the second tubing (unclamped) by a hydraulic tong, a manipulator extends to push the first tubing away from the wellhead, thereby realizing the pulling out of the first tubing. When mechanically running tubing, generally, the top (coupling end) of the first tubing to be run is lifted by a hook, and then the first tubing is lifted above the second tubing fixed at the wellhead by the tubing chuck by the hook. When the bottom of the first tubing is aligned with the top of the second tubing clamped by the tubing chuck, the bottom of the first tubing is connected to the top of the second tubing (clamped) by a hydraulic tong, and then the first tubing is run into the well, thereby realizing the running of the first tubing.

[0004] When pulling out tubing, when encountering the situation of a skewed wellhead or the shaking of the derrick base suspending the hook, it will cause the upper part of the second tubing lifted by the hook to be inclined relative to the wellhead or deviate from the center of the wellhead, and further cause the jaws of the tubing chuck to fail to fall smoothly to clamp the upper part of the second tubing, so that the first tubing cannot be removed from the second tubing. When running tubing, when encountering the situation of a skewed wellhead or the shaking of the derrick base suspending the hook, it will cause the upper part of the first tubing lifted by the hook to be inclined relative to the wellhead or deviate from the center of the wellhead, and also cause the jaws of the tubing chuck to fail to fall smoothly to clamp the upper part of the first tubing run into the well. When the tubing chuck cannot fall smoothly to clamp the tubing that needs to be fixed during the process of pulling out or running tubing, the tubing needs to be manually centralized by the staff before the jaws of the tubing chuck can fall to clamp the tubing, which is time-consuming and laborious during pulling and running tubing, reduces the construction efficiency of pulling and running tubing, and thus reduces the construction efficiency of workover. Summary of the Invention

[0005] The embodiments of this application provide a centralizer and a centralizing method, which can improve the construction efficiency of workover. The technical solution is as follows:

[0006] On the one hand, a centralizer is provided, and the centralizer includes: a body, at least three centralizing jaws, a gear, and a driving device;

[0007] The at least three centralizing slips are arranged in the body, and one end of the at least three centralizing slips is connected to the inner side of the body through a first shaft;

[0008] The sides of the at least three centralizing slips are engaged with the inner surface of the gear sleeved on the body;

[0009] The gear is engaged with the driving device;

[0010] A first through hole is arranged at the center of the body for the tubing to be centralized to pass through the first through hole and enter the body;

[0011] The driving device is used to drive the other ends of the at least three centralizing slips to close towards the first through hole through the gear, so as to centralize the tubing.

[0012] In a possible implementation manner, the centralizer further includes a first fixing frame;

[0013] The first fixing frame is connected to the bottom of the body, and the driving device is arranged on the first fixing frame;

[0014] The first fixing frame is used to fix the driving device on the body.

[0015] In a possible implementation manner, each centralizing slip is provided with a first shaft;

[0016] At least three second through holes are arranged at at least three positions of the body, and the at least three positions are positions connected to the at least three centralizing slips;

[0017] The first shafts of the at least three centralizing slips respectively pass through one of the second through holes and are fixedly connected to the body, so that the at least three centralizing slips respectively rotate back and forth around the first shaft in the body simultaneously based on the at least three second through holes.

[0018] In a possible implementation manner, each centralizing slip is provided with a third through hole for the first shaft to pass through and be connected to the centralizing slip.

[0019] In a possible implementation manner, the centralizer further includes a plurality of first rollers and a plurality of second fixing frames;

[0020] One end of each of the plurality of second fixing frames is fixed on the upper surface of the body, and the other end of each of the plurality of second fixing frames is connected to one of the plurality of first rollers through a second shaft, wherein one second fixing frame is connected to one first roller;

[0021] The plurality of first rollers disposed on the upper surface of the gear are used to prevent the gear from tilting upward when rotating.

[0022] In a possible implementation manner, the centralizer further includes a plurality of second rollers and a plurality of third fixing brackets;

[0023] One end of the plurality of third fixing brackets is fixed to the lower side surface of the body, and the other end of the plurality of third fixing brackets is connected to the plurality of second rollers through a third shaft, wherein one third fixing bracket is connected to one second roller;

[0024] The plurality of second rollers disposed below the gear are used to support the gear and reduce the frictional force when the gear rotates.

[0025] In a possible implementation manner, the upper surface of the gear meshes with the driving device; or, the outer surface of the gear meshes with the driving device.

[0026] In a possible implementation manner, at least three openings are provided on the side surface of the body, and one end of the at least three centralizing slips passes through the at least three openings and meshes with the gear sleeved on the body.

[0027] In a possible implementation manner, a first flange is provided at the top of the body, and a second flange is provided at the bottom of the body. The first flange and the second flange are used to connect the blowout preventer and the tubing chuck required for matching the upper and lower tubing.

[0028] On the other hand, a centralizing method is provided, and the method includes:

[0029] When pulling out the tubing, install the centralizer described in any of the above implementation manners between the blowout preventer and the tubing chuck. The first tubing is a tubing to be pulled out, the bottom of the first tubing is connected to the top of the second tubing in the oil well, and the bottom of the second tubing is connected to other tubing in the oil well;

[0030] Control the hook to lift the first tubing, the second tubing and other tubing in the oil well, and make the top end of the second tubing pass through the first through hole of the body to reach the make-up height of the hydraulic tongs;

[0031] Remotely control the driving device to rotate in the first direction, and drive the other ends of the at least three centralizing slips to converge towards the first through hole through the gear to centralize the second tubing;

[0032] After the second tubing is centralized, remotely control the tubing chuck to fix the upper part of the second tubing;

[0033] After the upper part of the second tubing is fixed by the tubing chuck, remove the first tubing from the second tubing;

[0034] The remote control manipulator pushes the first tubing away from the wellhead, thus realizing the removal of the first tubing.

[0035] On the other hand, a tubing straightening method is provided, and the method includes:

[0036] When running the tubing, install the straightener described in any of the above implementation manners between the blowout preventer and the tubing chuck. Wherein, the first tubing is a tubing to be run in, the second tubing is a tubing fixed to the wellhead by the tubing chuck, and after the upper part of the second tubing is straightened by the straightener, the upper part of the second tubing is fixed by the tubing chuck;

[0037] Control the crown block to lift the first tubing, move the first tubing to the upper part of the second tubing and align it with the second tubing, and then connect the first tubing and the second tubing;

[0038] Remotely control the tubing chuck to release the upper part of the second tubing, remotely control the driving device to rotate in the second direction, and drive at least three straightening jaws to move the other ends away from the first through hole, that is, away from the second tubing;

[0039] Control the crown block to lower the first tubing, pass the first tubing through the first through hole of the body and enter the body; when the top of the first tubing reaches the make-up height of the hydraulic tongs, stop lowering;

[0040] Remotely control the driving device to rotate in the first direction, drive the other ends of the at least three straightening jaws to converge towards the first through hole by means of the gear, and straighten the first tubing;

[0041] After the first tubing is straightened, remotely control the tubing chuck to fix the upper part of the first tubing. Thus, the running-in of the first tubing is realized.

[0042] The beneficial effects of the technical solution provided by the embodiments of the present application at least include:

[0043] In the embodiment of the present application, since there are at least three centralizing slips provided inside the body, one end of each centralizing slip is connected to the side of the body through a first shaft, and the side teeth at the third through-hole end of each centralizing slip are connected to a driving device arranged outside the body through gears. In this way, the driving device can drive at least three centralizing slips to converge towards the center of the body around the first shaft connected thereto, and the tubing to be centralized is placed inside the body through the first through-hole at the center of the body. In this way, at least three centralizing slips can centralize the tubing, making the tubing concentric with the wellhead, thereby avoiding the problem that the slips of the tubing chuck cannot fall due to the deviation of the tubing from the center of the wellhead and cannot grip the tubing. There is no need to manually centralize the tubing, which saves time and effort, and thus improves the construction efficiency of workover wells. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following-described drawings are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0045] Figure 1 is a schematic structural diagram of a centralizing component of a centralizer provided by an embodiment of the present application;

[0046] Figure 2 is a schematic structural diagram of a centralizer provided by an embodiment of the present application;

[0047] Figure 3 is a schematic structural diagram of a centralizing slip of a centralizer provided by an embodiment of the present application;

[0048] Figure 4 is a schematic structural diagram of a gear of a centralizer provided by an embodiment of the present application;

[0049] Figure 5 is a schematic structural diagram of a body of a centralizer provided by an embodiment of the present application;

[0050] Figure 6 is a schematic top view structural diagram of a centralizer provided by an embodiment of the present application;

[0051] Figure 7 is a working flow chart of a centralizer for lifting tubing provided by an embodiment of the present application;

[0052] Figure 8 is a working flow chart of a centralizer for lowering tubing provided by an embodiment of the present application.

[0053] The reference numerals in the drawings are respectively represented as:

[0054] 1 - Body;

[0055] 101 - First through hole;

[0056] 102 - Second through hole;

[0057] 2 - Centralizer slip;

[0058] 201 - First shaft;

[0059] 202 - Third through hole;

[0060] 203 - First tooth;

[0061] 3 - Gear;

[0062] 301 - Fourth through hole;

[0063] 302 - Second tooth;

[0064] 303 - Fourth tooth;

[0065] 4 - Driving device;

[0066] 401 - Hydraulic motor;

[0067] 402 - Output shaft;

[0068] 403 - Third tooth;

[0069] 5 - First fixing bracket;

[0070] 6 - First roller;

[0071] 601 - Second shaft;

[0072] 7 - Second fixing bracket;

[0073] 8 - Second roller;

[0074] 801 - Third shaft;

[0075] 9 - Third fixing bracket;

[0076] 10 - First flange;

[0077] 11 - Second flange. Detailed implementation manners

[0078] To make the objectives, technical solutions and advantages of this application clearer, the following will further describe the implementation manners of this application in detail with reference to the accompanying drawings.

[0079] In the description, claims and drawings of this application, terms such as "first", "second", "third" and "fourth" are used to distinguish different objects, rather than to describe a specific order. In addition, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device that includes a series of steps or units is not limited to the listed steps or units, but optionally further includes steps or units not listed, or optionally further includes other steps or units inherent to these processes, methods, products or devices.

[0080] An embodiment of this application provides a centralizer. Refer to Figure 1 , the centralizer includes a body 1, at least three centralizing slips 2, a gear 3 and a driving device 4. At least three centralizing slips 2 are arranged in the body 1, and one end of at least three centralizing slips 2 is connected to the inner side of the body 1 through a first shaft 201. The sides of at least three centralizing slips 2 are meshed with the inner surface of the gear 3 sleeved on the body 1, and the gear 3 is meshed with the driving device 4. A first through hole 101 is provided at the center of the body 1 for the tubing to be centralized to pass through the first through hole 101 and enter the body 1. The driving device 4 is used to drive the other ends of at least three centralizing slips 2 to converge towards the first through hole 101 through the gear 3 to centralize the tubing.

[0081] In the embodiment of this application, since at least three centralizing slips 2 are arranged in the body 1, one end of each centralizing slip 2 is connected to the inner side of the body 1 through a first shaft 201, and the side of each centralizing slip 2 is connected to the driving device 4 arranged outside the body 1 through a gear 3. In this way, the driving device 4 can drive at least three centralizing slips 2 to converge towards the center of the body 1 around the first shaft 201 connected thereto through the gear 3. The tubing to be centralized enters the body 1 through the first through hole 101 at the center of the body 1. In this way, at least three centralizing slips 2 can centralize the tubing, making the tubing concentric with the wellhead, thus avoiding the problem that the slips of the tubing chuck cannot fall due to the deviation of the tubing from the center of the wellhead and cannot clamp the tubing. There is no need to manually centralize the tubing, which saves time and effort, and further improves the construction efficiency of well workover.

[0082] Refer to Figure 1 and Figure 2 , the body 1 is a hollow cylinder, at least three centralizing slips 2 are arranged inside the body 1, and the body 1 is connected to at least three centralizing slips 2 through a first shaft 201.

[0083] Among them, each centralizer slip 2 is provided with a first shaft 201, and at least three second through holes 102 are provided at at least three positions of the body 1. The at least three positions are the positions connected to at least three centralizer slips 2. The first shafts 201 of at least three centralizer slips 2 respectively pass through a second through hole 102 and are fixedly connected to the body 1, so that at least three centralizer slips 2 respectively rotate back and forth around the first shaft 201 in the body 1 based on at least three second through holes 102.

[0084] Among them, the diameter of the first shaft 201 matches the diameter of the second through hole 102, so that the first shaft 201 can pass through the second through hole 102. The length of the first shaft 201 matches the thickness of the body 1, so that the first shaft 201 can pass through the upper surface and the lower surface of the body 1 and does not extend to the outside of the body 1.

[0085] See Figure 3 , each centralizer slip 2 is provided with a third through hole 202, and the third through hole 202 is arranged at the end of the centralizer slip 2 that meshes with the gear, and is used for the first shaft 201 to pass through the third through hole 202 and be connected to the centralizer slip 2. The diameter of the first shaft 201 matches the diameter of the third through hole 202, so that the first shaft 201 can pass through the third through hole 202. When at least three centralizer slips 2 rotate, at least three centralizer slips 2 can rotate around at least three first shafts 201 connected to the body 1 in the body 1 around the first shaft 201.

[0086] Continue to see Figure 1 , at least three centralizer slips 2 are in the shape of petals and are evenly distributed inside the body 1.

[0087] Among them, the number of centralizer slips 2 is at least three, that is, the number of centralizer slips 2 can be three, four, five, etc.; when the number of centralizer slips 2 is three, the three centralizer slips 2 are evenly distributed inside the body 1 and are 120 degrees apart from each other. When the number of centralizer slips 2 is four, the four centralizer slips 2 are evenly distributed inside the body 1 and are 90 degrees apart from each other. When the number of centralizer slips 2 is five, the five centralizer slips 2 are evenly distributed inside the body 1 and are 72 degrees apart from each other.

[0088] Continue to see Figure 2 , a first through hole 101 is provided at the center of the body 1, and is used for the tubing to be centralized to pass through the first through hole 101 and enter the body 1.

[0089] Among them, the diameter of the first through hole 101 is not less than the through diameter of the blowout preventer, and can not only allow the tubing to be centralized to pass through, but also allow various downhole tools such as tubing hangers, packers, anchor devices, gas anchors, sand anchors, water distributors, etc. to pass through, so that these components can pass through the centralizer.

[0090] Continue to see Figure 1At least three straightening slips 2 are evenly distributed around the first through hole 101. When the oil pipe needs to be straightened, one end of at least three straightening slips 2 close to the first through hole 101 is retracted toward the first through hole 101. Through the cooperation of at least three straightening slips 2, the oil pipe to be straightened is clamped to straighten the oil pipe.

[0091] In another possible implementation, the body 1 is also used to allow drilling casing, drill pipe and other pipes to pass through, so that at least three straightening slips 2 straighten the drilling casing, drill pipe and other pipes.

[0092] Continue to see Figure 2 A gear 3 is sleeved on the outside of the body 1 , and the side surfaces of at least three straightening slips 2 in the body 1 are meshed with the inner surface of the gear 3 .

[0093] See also Figure 4 The gear 3 is shaped like a hollow circular cover, including a side surface, an upper surface and a lower surface. A fourth through hole 301 is provided at the center of the gear 3, and the inner diameter of the fourth through hole 301 is slightly larger than the outer diameter of the body 1, so that the body 1 can pass through the fourth through hole 301, and the gear 3 can be sleeved on the outside of the body 1.

[0094] The side surfaces of at least three righting slips 2 are provided with first teeth 203 , the inner surface of the gear 3 is provided with second teeth 302 matching the first teeth 203 , and the three righting slips 2 and the gear 3 are meshed through the first teeth 203 and the second teeth 302 .

[0095] See also Figure 5 At least three openings are provided on the side of the body 1, and one end of the first teeth 203 of at least three righting slips 2 passes through the at least three openings and meshes with the gear 3 sleeved on the body 1. The spatial dimensions of the three openings match the installation and rotation range of the at least three righting slips 2, so that the righting slips 2 can rotate back and forth.

[0096] In the embodiment of the present application, a gear 3 meshing with at least three righting slips 2 is provided. When the gear 3 rotates, it can drive the at least three righting slips 2 meshing with it to retract toward the first through hole 101 of the body 1 to right the oil pipe.

[0097] Continue to see Figure 2 , the gear 3 is meshed with the driving device 4, wherein the upper surface of the gear 3 is meshed with the driving device 4; or, the outer surface of the gear 3 is meshed with the driving device 4.

[0098] Among them, the driving device 4 includes a hydraulic motor 401 and an output shaft 402. The driving device 4 is a hydraulic driving device 4. The hydraulic motor 401 and the output shaft 402 are connected by a transmission shaft. One end of the transmission shaft is connected to the hydraulic motor 401, and the other end is connected to the output shaft 402. The transmission shaft is used to transmit the power of the hydraulic motor 401 to the output shaft 402.

[0099] Among them, the output shaft 402 is installed at one end of the driving device 4 that meshes with the gear 3, and the hydraulic motor 401 is installed at the other end of the driving device 4. The hydraulic motor 401 can be installed at the other end of the driving device 4 in a horizontal or vertical manner.

[0100] In a possible implementation manner, a circumferential third tooth 403 is provided on the output shaft 402, and a fourth tooth 303 matching the third tooth 403 is provided on the side surface of the gear 3. The driving device 4 and the gear 3 are meshed through the third tooth 403 and the fourth tooth 303.

[0101] In another possible implementation manner, a circumferential third tooth 403 is provided on the output shaft 402, and a fifth tooth matching the third tooth 403 is provided on the upper surface of the gear 3. The driving device 4 and the gear 3 are meshed through the third tooth 403 and the fifth tooth.

[0102] When the hydraulic motor 401 of the driving device 4 starts, after the hydraulic motor 401 transmits the power it generates to the output shaft 402, the output shaft 402 starts to rotate, and then drives the gear 3 meshing with the output shaft 402 to rotate in the opposite direction. The gear 3 drives at least three centralizing slips 2 to close towards the first through hole 101 of the body 1 to centralize the tubing.

[0103] In a possible implementation manner, the hydraulic motor 401 can also be replaced with other devices such as an explosion-proof motor to provide power.

[0104] Continue to refer to Figure 2 , the centralizer further includes a first fixing frame 5. The first fixing frame 5 is connected to the bottom of the body 1, and the driving device 4 is arranged on the first fixing frame 5. The first fixing frame 5 is used to fix the driving device 4 on the body 1.

[0105] In a possible implementation manner, the first fixing frame 5 and the body 1 are connected by welding. The first fixing frame 5 is welded to the bottom of the body 1, making the connection between the body 1 and the first fixing frame 5 more firm.

[0106] In another implementation manner, the first fixing frame 5 and the body 1 are connected by threading. The first fixing frame 5 is provided with a first internal thread hole, and the body 1 is provided with a second internal thread hole. Screws sequentially pass through the first internal thread hole and the second internal thread hole to realize the connection between the first fixing frame 5 and the body 1.

[0107] Among them, the upper end of the first fixing frame 5 is provided with a plurality of supporting plates, and the plurality of supporting plates are used to support the driving device 4 to realize the connection between the driving device 4 and the first fixing frame 5.

[0108] Continue to refer to Figure 2 , the aligner further includes a plurality of first rollers 6 and a plurality of second fixing frames 7. One end of the plurality of second fixing frames 7 is fixed on the upper surface of the body 1, and the other end of the plurality of second fixing frames 7 is connected to the plurality of first rollers 6 through a second shaft 601. Among them, one second fixing frame 7 is connected to one first roller 6, and the plurality of first rollers 6 arranged on the upper surface of the gear 3 are used to prevent the gear 3 from tilting upwards when rotating.

[0109] Among them, the number of the first rollers 6 matches the number of the second fixing frames 7. The number of the first rollers 6 can be set and changed as needed, and no specific limitation is made here; for example, if the number of the first rollers 6 is 4-6, then the number of the second fixing frames 7 is 4-6.

[0110] When the driving device 4 drives the gear 3 to rotate, since the driving device 4 only meshes with one end of the gear 3, the driving device 4 only applies pressure to one end of the gear 3. Then, during the rotation of the gear 3, the overall force on the gear 3 may be uneven, and the part of the gear 3 that is not meshed with the driving device 4 may tilt upwards due to no pressure being applied. In the embodiment of the present application, by providing a plurality of first rollers 6 and a plurality of second fixing frames 7, the plurality of first rollers 6 press on the upper surface of the gear 3, and during the rotation of the gear 3, the plurality of first rollers 6 rotate along with the gear 3, which can prevent the gear 3 from tilting upwards when rotating.

[0111] Refer to Figure 6 , the aligner further includes a plurality of second rollers 8 and a plurality of third fixing frames 9. One end of the plurality of third fixing frames 9 is fixed on the lower side surface of the body 1, and the other end of the plurality of third fixing frames 9 is connected to the plurality of second rollers 8 through a third shaft 801. Among them, one third fixing frame 9 is connected to one second roller 8, and the plurality of second rollers 8 arranged under the gear 3 are used to support the gear 3 to reduce the friction when the gear 3 rotates.

[0112] Among them, the number of the second rollers 8 matches the number of the third fixing frames 9. The number of the second rollers 8 can be set and changed as needed, and no specific limitation is made here; for example, if the number of the second rollers 8 is 4-8, then the number of the third fixing frames 9 is 4-8.

[0113] The gear 3 is sleeved outside the body 1. Since the inner diameter of the gear 3 is greater than the outer diameter of the body 1, the gear 3 and the body 1 are only meshed through the first teeth 203 of at least three centering slips 2, and the lower surface of the gear 3 has no support. In the embodiment of the present application, by arranging a plurality of second rollers 8 and a plurality of third fixing frames 9, on the one hand, the plurality of second rollers 8 are arranged on the lower surface of the gear 3 to support the gear 3 and prevent the gear 3 from shaking during rotation; on the other hand, the plurality of second rollers 8 are arranged on the lower surface of the gear 3, and during the rotation of the gear 3, along with the rotation of the gear 3, the resistance encountered by the gear 3 during rotation can be reduced.

[0114] Continue to refer to Figure 5 , a first flange 10 is provided at the top of the body 1, and a second flange 11 is provided at the bottom of the body 1. The first flange 10 and the second flange 11 are used to connect the blowout preventer and the tubing chuck that need to be matched for the lower tubing.

[0115] Among them, a plurality of first bolt holes are uniformly distributed on the first flange 10. A third flange is provided at the bottom of the tubing chuck, and a plurality of second bolt holes matching the plurality of first bolt holes are uniformly distributed on the third flange. A plurality of bolts pass through the plurality of first threaded holes and the plurality of second bolt holes to realize the connection between the first flange 10 and the third flange, and further realize the connection between the body 1 and the tubing chuck.

[0116] Among them, the number of the first bolt holes can be set and changed according to needs, and no specific limitation is made here; for example, if the number of the first bolt holes is 12, then the number of the second bolt holes is 12. The diameter of the first bolt holes can be set and changed according to needs, and no specific limitation is made here; for example, if the diameter of the first bolt holes is 32 mm, then the diameter of the second bolt holes is 32 mm.

[0117] Among them, a plurality of third bolt holes are uniformly distributed on the second flange 11. A fourth flange is provided at the top of the blowout preventer, and a plurality of fourth bolt holes matching the plurality of third bolt holes are uniformly distributed on the fourth flange. A plurality of bolts pass through the plurality of third threaded holes and the plurality of fourth bolt holes to realize the connection between the second flange 11 and the fourth flange, and further realize the connection between the body 1 and the blowout preventer.

[0118] Among them, the number of the third bolt holes can be set and changed according to needs, and no specific limitation is made here; for example, if the number of the third bolt holes is 12, then the number of the fourth bolt holes is 12. The diameter of the third bolt holes can be set and changed according to needs, and no specific limitation is made here; for example, if the diameter of the third bolt holes is 32 mm, then the diameter of the fourth bolt holes is 32 mm.

[0119] In another possible implementation, when a blowout preventer is not provided on the wellhead, the second flange 11 is used to connect to the wellhead that needs to be matched with the tubing running in and out. The top of the wellhead is provided with a fifth flange, and a plurality of fifth bolt holes matching a plurality of third bolt holes are evenly distributed on the fifth flange. A plurality of bolts pass through the plurality of third threaded holes and the plurality of fifth bolt holes to realize the connection between the second flange 11 and the fifth flange, and further realize the connection between the body 1 and the wellhead.

[0120] In the embodiment of the present application, since at least three centralizing slips 2 are provided in the body 1, one end of each centralizing slip 2 is connected to the side of the body 1 through a first shaft 201, and the side teeth at the third through-hole end of each centralizing slip 2 are connected to a driving device 4 provided outside the body 1 through a gear 3. In this way, the driving device 4 can drive at least three centralizing slips 2 to converge towards the center of the body 1 around the first shaft 201 connected to the body through the gear 3, and the tubing to be centralized is located inside the body 1 through the first through-hole 101 in the center of the body 1. In this way, at least three centralizing slips 2 can centralize the tubing, making the tubing concentric with the wellhead, thus avoiding the problem that the slips of the tubing chuck cannot fall due to the deviation of the tubing from the center of the wellhead and cannot grip the tubing. There is no need to manually centralize the tubing, which saves time and effort, and further improves the construction efficiency of workover.

[0121] The embodiment of the present application provides a centralizing method. Refer to Figure 7 , and the method includes:

[0122] Step 701: When pulling out the tubing, install the centralizer between the blowout preventer and the tubing chuck. The first tubing is a tubing to be pulled out, the bottom of the first tubing is connected to the top of the second tubing in the oil well, and the bottom of the second tubing is connected to other tubings in the oil well;

[0123] Among them, the centralizer is installed between the blowout preventer and the tubing chuck through the first flange 10 and the second flange 11. The connection between the centralizer and the tubing chuck is realized by connecting the first flange 10 to the third flange at the bottom of the tubing chuck, and the connection between the centralizer and the blowout preventer is realized by connecting the second flange 11 to the fourth flange at the top of the blowout preventer.

[0124] In another possible implementation, when a blowout preventer is not provided on the wellhead, install the centralizer between the wellhead and the tubing chuck.

[0125] Among them, the centralizer is installed between the blowout preventer and the tubing chuck through the first flange 10 and the second flange 11. The connection between the centralizer and the tubing chuck is realized by connecting the first flange 10 to the third flange at the bottom of the tubing chuck, and the connection between the centralizer and the wellhead is realized by connecting the second flange 11 to the fifth flange at the top of the wellhead.

[0126] Step 702: Control the crown block to lift the first tubing string, the second tubing string and other tubing strings in the oil well, and make the top end of the second tubing string pass through the first through hole 101 of the body 1 to reach the make-up height of the hydraulic tongs.

[0127] Among them, control the crown block to lift the top end of the first tubing string to be pulled out of the well, lift the first tubing string until the top (i.e., the coupling) of the second tubing string connected to the bottom of the first tubing string reaches the height where the hydraulic tongs for releasing the connection are located; at this time, the first tubing string is suspended above the second tubing string, and the second tubing string passes through the blowout preventer, the centralizer and the tubing spider from bottom to top in sequence, and the top end of the second tubing string passes through the tubing spider, and the upper part of the second tubing string is located in the tubing spider, the first through hole 101 of the body 1 and the blowout preventer in sequence.

[0128] Step 703: Remotely control the driving device 4 to rotate in the first direction, and drive the other ends of at least three centralizing slips 2 to close towards the first through hole 101 through the gear 3 to centralize the second tubing string.

[0129] Among them, the output shaft 402 of the remotely controlled driving device 4 rotates in the first direction. Since the output shaft 402 meshes with the gear 3, the gear 3 is driven to rotate in the opposite direction of the first direction. Since the gear 3 meshes with the other ends of at least three centralizing slips 2, the gear 3 drives at least three centralizing slips 2 to close towards the first through hole 101. Through the cooperation of the three centralizing slips 2, the second tubing string to be centralized is clamped to centralize the second tubing string.

[0130] Step 704: After the second tubing string is centralized, remotely control the tubing spider to fix the upper part of the second tubing string.

[0131] Among them, the upper part of the second tubing string is located in the tubing spider. The tubing spider is provided with slips for clamping the second tubing string, and the centralizer and the tubing spider are linked. After at least three centralizing slips 2 of the centralizer centralize the second tubing string, the tubing spider is automatically triggered to fix the upper part of the second tubing string.

[0132] Step 705: After the upper part of the second tubing string is fixed by the tubing spider, remove the first tubing string from the second tubing string.

[0133] After the upper part of the second tubing string is fixed by the tubing spider, use the hydraulic tongs to remove the bottom of the first tubing string from the top of the second tubing string (release the connection), that is, open the thread connection between the first tubing string and the second tubing string to separate the first tubing string from the second tubing string.

[0134] Step 706: Remotely control the manipulator to push the first tubing string away from the wellhead to complete the pulling out of the first tubing string.

[0135] Repeat steps 702 - 706 and proceed in sequence to pull out all the tubing strings in the well.

[0136] In the embodiment of the present application, the centralizer can drive at least three centralizing slips to converge towards the center of the centralizer, and the second tubing to be centralized is located at the center of the centralizer. Therefore, by driving at least three centralizing slips of the centralizer to converge towards the center of the centralizer, the second tubing can be easily centralized. After the second tubing is centralized, the upper part of the second tubing is fixed by the tubing chuck, and then the first tubing can be removed from the top of the second tubing to realize the retrieval of the first tubing. Thus, at least three centralizing slips 2 of the centralizer can centralize the second tubing, making the second tubing concentric with the wellhead, thereby avoiding the problem that the slips of the tubing chuck cannot fall due to the deviation of the second tubing from the wellhead center and cannot grip the second tubing. There is no need to manually centralize the tubing, which saves time and effort and improves the construction efficiency of workover operations.

[0137] The embodiment of the present application provides another centralizing method. Refer to Figure 8 , and this method includes:

[0138] Step 801: When running the tubing, install the centralizer between the blowout preventer and the tubing chuck. Here, the first tubing is a tubing to be run in, the second tubing is a tubing fixed to the wellhead by the tubing chuck, and after the upper part of the second tubing is centralized by the centralizer, the upper part of the second tubing is fixed by the tubing chuck.

[0139] Among them, the specific implementation manner of step 801 is the same as that of step 701 and will not be elaborated here.

[0140] Step 802: Control the traveling block to lift the first tubing. After moving the first tubing to the upper part of the second tubing and aligning it with the second tubing, connect the first tubing and the second tubing.

[0141] The collar end at the top of the first tubing to be run in is lifted by the traveling block, the first tubing is lifted above the wellhead, and after being centered with the second tubing at the wellhead, the first tubing is slightly lowered by the traveling block so that the threaded end at the bottom of the first tubing falls into the collar of the second tubing, and the upper joint is made by the hydraulic tongs to connect the bottom of the first tubing and the top of the second tubing together.

[0142] Step 803: Remotely control the tubing chuck to release the upper part of the second tubing, and remotely control the driving device 4 to rotate in the second direction, driving the other ends of at least three centralizing slips 2 away from the first through hole 101, that is, away from the second tubing.

[0143] Among them, the centralizer and the tubing chuck are under interlocking control. When the tubing chuck releases the second tubing, at least three centralizing slips 2 of the centralizer are automatically triggered to move away from the second tubing.

[0144] Among them, the output shaft 402 of the remote control driving device 4 rotates in the second direction, driving the gear 3 to rotate in the opposite direction of the second direction, and the gear 3 drives the other ends of at least three straightening cavas 2 away from the first through hole 101 to stay away from the second oil pipe, that is, the straightening cavas 2 return to the position in the main body 1 before the second oil pipe is straightened.

[0145] Step 804: Control the big hook to lower the first oil pipe, pass the first oil pipe through the first through hole 101 of the main body 1, and enter the main body 1. When the top end of the first oil pipe reaches the buckling height of the hydraulic clamp, stop lowering.

[0146] The big hook is controlled to lower the first oil pipe, so that the first oil pipe passes through the oil pipe chuck, the centralizer and the blowout preventer from top to bottom in sequence and enters the well, and the top of the first oil pipe is higher than the oil pipe chuck and is at the buckling height of the hydraulic clamp, and the upper part of the first oil pipe is located in the oil pipe chuck, the first through hole 101 of the body 1 and the blowout preventer in sequence.

[0147] Step 805: The remotely controlled driving device 4 rotates in the first direction, and drives the other ends of at least three straightening slips 2 to be retracted toward the first through hole 101 through the gear 3, so as to straighten the upper part of the first oil pipe.

[0148] Among them, the output shaft 402 of the remote control driving device 4 rotates in the first direction. Since the output shaft 402 is engaged with the gear 3, the gear 3 is driven to rotate in the opposite direction of the first direction. Since the gear 3 is engaged with the other end of at least three straightening cavas 2, the gear 3 drives at least three straightening cavas 2 to converge toward the first through hole 101. Through the cooperation of the three straightening cavas 2, the first oil pipe to be straightened is clamped, and the first oil pipe is straightened.

[0149] Step 806: After the first oil pipe is straightened, the oil pipe chuck is remotely controlled to fix the upper part of the first oil pipe. At this point, the first oil pipe is lowered.

[0150] Among them, the upper part of the first oil pipe is located in the oil pipe chuck, and a cava for clamping the first oil pipe is provided in the oil pipe chuck, and the centralizer and the oil pipe chuck are linked. After at least three straightening cava 2 of the centralizer straighten the first oil pipe, the oil pipe chuck is automatically triggered to fix the first oil pipe, thereby realizing the lowering of the first oil pipe.

[0151] Repeat steps 802-606 in sequence to lower all the oil pipes into the well.

[0152] In the embodiment of the present application, the centralizer can drive at least three straightening slips to converge or move away from the center of the centralizer, and the first oil pipe to be straightened is located at the center of the centralizer. Therefore, by driving at least three straightening slips to converge toward the center of the centralizer, the first oil pipe can be straightened easily. After the first oil pipe is straightened, the upper part of the first oil pipe is fixed by the oil pipe chuck, thereby realizing the lowering of the first oil pipe. It can be seen that at least three straightening slips 2 of the centralizer can straighten the first oil pipe so that the first oil pipe is concentric with the wellhead, thereby avoiding the problem that the second oil pipe deviates from the center of the wellhead and affects the slips of the oil pipe chuck to fall and cannot clamp the first oil pipe. There is no need to straighten the oil pipe manually, which saves time and effort, thereby improving the construction efficiency of well repair.

[0153] The above description is only an optional embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A centralizer, characterized in that, The centralizer comprises: a body (1), at least three centralizing slips (2), a gear (3), a driving device (4), a plurality of first rollers (6), a plurality of second fixing frames (7), a plurality of second rollers (8) and a plurality of third fixing frames (9); The at least three righting slips (2) are arranged in the body (1), and one end of the at least three righting slips (2) is connected to the inner side of the body (1) via a first shaft (201); The side surfaces of the at least three straightening slips (2) are meshed with the inner surface of the gear (3) sleeved on the body (1); The gear (3) is meshed with the driving device (4); A first through hole (101) is provided at the center of the body (1), for allowing the oil pipe to be straightened to pass through the first through hole (101) and enter the body (1); The top of the body (1) is provided with a first flange (10), and the bottom of the body (1) is provided with a second flange (11), wherein the first flange (10) and the second flange (11) are used to connect a blowout preventer and a tubing chuck that are required to match the tubing; The driving device (4) is used for driving the other ends of the at least three straightening slips (2) to be retracted toward the first through hole (101) via the gear (3) to straighten the oil pipe; One end of the plurality of second fixing frames (7) is fixed to the upper surface of the body (1), and the other end of the plurality of second fixing frames (7) is connected to the plurality of first rollers (6) via a second shaft (601), wherein one second fixing frame (7) is connected to one first roller (6); The plurality of first rollers (6) arranged on the upper surface of the gear (3) are used to prevent the gear (3) from tilting upward when rotating; One end of the plurality of third fixing frames (9) is fixed to the lower side surface of the body (1), and the other end of the plurality of third fixing frames (9) is connected to the plurality of second rollers (8) via a third shaft (801), wherein one third fixing frame (9) is connected to one second roller (8); The plurality of second rollers (8) arranged at the bottom of the gear (3) are used to support the gear (3) and reduce friction when the gear (3) rotates.

2. The centralizer according to claim 1, wherein, The centralizer further comprises a first fixing frame (5); The first fixing frame (5) is connected to the bottom of the body (1), and the driving device (4) is arranged on the first fixing frame (5); The first fixing frame (5) is used to fix the driving device (4) on the main body (1).

3. The centralizer according to claim 1, wherein, Each of the righting slips (2) is provided with a first shaft (201); At least three second through holes (102) are provided at at least three positions of the body (1), and the at least three positions are positions connected to the at least three righting slips (2); The first shafts (201) of the at least three centralizing slips (2) respectively pass through one of the second through holes (102) and are fixedly connected to the body (1), so that the at least three centralizing slips (2) respectively rotate back and forth around the first shafts (201) in the body (1) based on the at least three second through holes (102).

4. The centralizer according to claim 3, characterized in that, Each of the centralizing slips (2) is provided with a third through hole (202) for the first shaft (201) to pass through and be connected to the centralizing slip (2).

5. The centralizer according to claim 1, characterized in that, The upper surface of the gear (3) meshes with the driving device (4); alternatively, the outer surface of the gear (3) meshes with the driving device (4).

6. A righting method, characterized in that, The method includes: When pulling out the tubing, install the centralizer according to any one of claims 1-5 between the blowout preventer and the tubing chuck. The first tubing is a tubing to be pulled out, the bottom of the first tubing is connected to the top of the second tubing in the oil well, and the bottom of the second tubing is connected to other tubings below it in the oil well. Control the crown block to lift the first tubing, the second tubing and other tubings in the oil well, and make the top end of the second tubing pass through the first through hole (101) of the body (1) to reach the make-up height of the hydraulic tongs. Remotely control the driving device (4) to rotate in the first direction, and drive the other ends of the at least three centralizing slips (2) to converge towards the first through hole (101) through the gear (3) to centralize the second tubing. After the second tubing is centralized, remotely control the tubing chuck to fix the upper part of the second tubing. After the upper part of the second tubing is fixed by the tubing chuck, remove the first tubing from the second tubing. Remotely control the manipulator to push the first tubing away from the wellhead, thus realizing the pulling out of the first tubing.

7. A righting method, characterized in that, The method includes: When running in the tubing, install the centralizer according to any one of claims 1-5 between the blowout preventer and the tubing chuck. Among them, the first tubing is a tubing to be run in, the second tubing is a tubing fixed to the wellhead by the tubing chuck, and after the upper part of the second tubing is centralized by the centralizer, the upper part of the second tubing is fixed by the tubing chuck. Control the crown block to lift the first tubing, move the first tubing to the upper part of the second tubing and align it with the second tubing, and then connect the first tubing and the second tubing. Remotely control the tubing chuck to release the upper part of the second tubing, remotely control the driving device (4) to rotate in the second direction, and drive the other ends of the at least three centralizing slips (2) to move away from the first through hole (101), that is, away from the second tubing, through the gear (3). Control the crown block to lower the first tubing, make the first tubing pass through the first through hole (101) of the body (1) and enter the body (1); when the top end of the first tubing reaches the make-up height of the hydraulic tongs, stop lowering. Remotely control the driving device (4) to rotate in the first direction, and drive the other ends of the at least three centralizing slips (2) to close towards the first through hole (101) through the gear (3) to centralize the first oil pipe; After the first oil pipe is centralized, remotely control the pipe chuck to fix the upper part of the first oil pipe. Thus, the lowering of the first oil pipe is realized.

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