A wear-resistant backup core for deepwater drilling in the sea

Abstract

The application discloses an anti-wear repair core for deepwater drilling of the sea, and relates to the technical field of offshore oil drilling and production equipment. The anti-wear repair core for deepwater drilling of the sea comprises a repair core assembly, the repair core assembly comprises a repair core body, a plurality of axial locking units arranged on the inner circumferential wall of the repair core body in a spaced manner and a recovery ring arranged on the top of the inner circumferential wall of the repair core body, the axial locking unit comprises an axial locking pin which can be horizontally moved towards the center of the repair core body, and a plurality of wellhead anti-rotation units for locking the wellhead are arranged on the outer circumferential wall of the repair core body; a retracting and releasing assembly, the retracting and releasing assembly comprises a lowering tool which passes through the repair core body and is used for connecting a drilling tool at the bottom, the lowering tool is externally provided with locking leaves which are equal in number to the axial locking pins and are opposite to the axial locking pins in position, transversely arranged grooves matched with the axial locking pins are formed on the locking leaves, and the top of the locking leaves is provided with a matching surface matched with the bottom of the recovery ring.

Description

Technical Field

[0001] The invention relates to the technical field of marine oil drilling equipment, in particular to an anti-wear core packing for marine deep-water drilling. Background Art

[0002] As countries around the world gradually intensify their exploration of offshore oil and gas, the application of subsea wellhead systems, as key equipment for offshore oil and gas exploration and development, is becoming increasingly widespread. Anti-wear bushings are key components of subsea wellhead systems, primarily used to protect the inner sealing surfaces of the subsea wellhead and casing hanger from damage during the drilling process.

[0003] Under conventional drilling conditions, each drilling operation requires first using a lowering tool to place the anti-wear bushing in place, then retrieving the lowering tool, lowering the drilling tool again, and then pulling out of the hole. Finally, the anti-wear bushing recovery tool must be lowered again to recover the anti-wear bushing. This results in at least three drill string trips during the entire drilling process. As the operating water depth increases, the time required for offshore drilling trips increases significantly. For example, at a water depth of 1,500 meters, a single trip takes 8 to 12 hours. For deepwater drilling platforms, which often have daily costs of millions of yuan, this not only wastes a large amount of human and material resources, is extremely uneconomical, but also significantly delays the project progress. Summary of the Invention

[0004] The present application provides an anti-wear core packing for deep-water marine drilling, which can solve the technical problems in the prior art that, during the process of offshore oil drilling and production, the anti-wear core packing and drilling tools need to be lowered and recovered separately, and the drill pipe needs to be raised and lowered in the drill pipe multiple times, which not only wastes a large amount of human and material resources for the deep-water marine drilling platform, but also greatly delays the progress of the project.

[0005] In a first aspect, an embodiment of the present application provides an anti-wear bushing for deep-water marine drilling, comprising:

[0006] A bushing assembly comprising a bushing body, a plurality of axial locking units spaced apart on the inner circumferential wall of the bushing body, and a recovery ring disposed on the top of the inner circumferential wall of the bushing body, wherein the axial locking units include axial locking pins that can move horizontally toward the center of the bushing body, and the outer circumferential wall of the bushing body is further provided with a plurality of wellhead anti-rotation units for locking the wellhead;

[0007] a retractable assembly, the retractable assembly comprising a lowering tool passing through the bushing body and having a bottom for connecting to a drilling tool; the lowering tool being provided with locking leaves on its periphery, the same number as and opposite to the axial locking pins; through-type grooves matching the axial locking pins being transversely formed on the outer sides of the locking leaves; and a fitting surface matching the bottom of the recovery ring being provided on the top of the locking leaves;

[0008] The bushing body is provided with first receiving grooves, the number of which is equal to the number of the axial locking units and which transversely penetrate the circumferential wall of the bushing body, and each of the first receiving grooves is provided with a group of the axial locking units;

[0009] A second accommodating groove is provided below each of the first accommodating grooves. The second accommodating grooves extend transversely through the circumferential wall of the bushing body. An annular locking pin is provided in each of the second accommodating grooves. The annular locking pin extends out of the second accommodating groove in a direction close to the center of the bushing body.

[0010] An annular locking groove is provided on the locking leaf, and one end of the annular locking pin extending out of the second accommodating groove is located in the annular locking groove.

[0011] In one embodiment, a step portion is provided at one end of the first accommodating groove close to the center of the bushing body, and a first return spring is transversely provided on the step portion for driving the axial locking pin to retract into the first accommodating groove.

[0012] In one embodiment, a first baffle plate for pushing the axial locking pin out of the first accommodating groove is provided at one end of the first accommodating groove away from the step portion, and an outer annular surface of the first baffle plate is threadedly connected to an inner wall of the first accommodating groove.

[0013] In one embodiment, a plurality of third accommodating grooves are formed on the bushing body. The third accommodating grooves are symmetrically arranged along the radial direction of the bushing body, and a wellhead anti-rotation unit is provided in each of the third accommodating grooves.

[0014] In one embodiment, the wellhead anti-rotation unit includes an anti-rotation pin extending out of the third receiving groove in a direction away from the center of the bushing body, and a second return spring is transversely provided at one end of the anti-rotation pin close to the center of the bushing body.

[0015] In one embodiment, a second retaining ring is provided at one end of the third accommodating groove away from the second return spring, and a through hole having the same shape as the outer end of the anti-rotation pin for the outer end of the anti-rotation pin to pass through is opened in the middle of the second retaining ring.

[0016] In one embodiment, a first inclined surface is provided on the top of the locking leaf, and a second inclined surface matching the first inclined surface is provided on the bottom of the recovery ring.

[0017] The beneficial effects of the technical solutions provided in the embodiments of the present application include:

[0018] The anti-wear bushing for deep-water offshore drilling disclosed in the present application can be locked with a through-type groove provided on a locking leaf by an axial locking pin provided on the inner wall of the bushing body, thereby facilitating lowering work. The bottom of the lowering tool is used to connect the drilling tool. After the bushing body is lowered, the bushing body can be quickly separated from the lowering tool by rotating the lowering tool, so as to facilitate the continued lowering of the drilling tool and the drilling work. With this structural arrangement, the drilling tool and the bushing body can be lowered synchronously. At the same time, a recovery ring with an inclined bottom is provided at the top of the inner wall of the bushing body, and a fitting surface matching the recovery ring is provided at the top of the locking leaf. When the lowering tool is raised, the locking leaf can be engaged with the recovery ring, thereby facilitating the synchronous recovery of the drilling tool and the bushing body. This eliminates the need for multiple raising and lowering of the drill during the drilling process, thereby saving a lot of construction time and greatly reducing construction costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0020] Figure 1 A schematic diagram of an anti-wear core packing structure for deep-water marine drilling provided in an embodiment of the present application;

[0021] Figure 2 A schematic diagram of the structure of an axial locking unit in an anti-wear lining for deep-water marine drilling provided by an embodiment of the present application;

[0022] Figure 3 A schematic diagram of a wear-resistant core lowering tool and a locking blade structure for deep-water marine drilling provided in an embodiment of the present application;

[0023] Figure 4 A schematic structural diagram of a wellhead anti-rotation unit for an anti-wear patching core used in deep-water marine drilling provided in an embodiment of the present application;

[0024] Figure 5 A schematic diagram of the structure of a circumferential locking pin in an anti-wear bushing for deep-water marine drilling provided by an embodiment of the present application;

[0025] Figure 6 This is a schematic diagram of the structure of the first and second inclined surfaces in an anti-wear packing for deep-water marine drilling provided in an embodiment of the present application.

[0026] In the figure: 1. core bushing body; 2. axial locking unit; 201. axial locking pin; 3. recovery ring; 301. second inclined surface; 4. lowering tool; 5. locking leaf; 501. through groove; 502. circumferential locking groove; 503. first inclined surface; 6. first accommodating groove; 601. step portion; 602. first return spring; 603. first baffle; 604. baffle ring; 7. second accommodating groove; 701. circumferential locking pin; 8. third accommodating groove; 9. wellhead anti-rotation unit; 901. anti-rotation pin; 902. second return spring; 903. second baffle; 10. wellhead anti-fall unit. DETAILED DESCRIPTION

[0027] In order to enable those skilled in the art to better understand the present invention, the following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0028] The embodiment of the present application provides an anti-wear core packing for deep-water marine drilling, which can solve the technical problem in the prior art that, during the process of offshore oil drilling and production, the anti-wear core packing and drilling tools need to be lowered and recovered separately, and the drill pipe needs to be raised and lowered in the drill pipe multiple times, which not only wastes a large amount of human and material resources for the deep-water marine drilling platform, but also greatly delays the progress of the project.

[0029] The anti-wear core bushing in the present application includes a core bushing assembly and a retractable assembly. The core bushing assembly is mainly used to fit the inner wall of the inlet to protect the underwater wellhead. The retractable assembly is mainly used to simultaneously connect the core bushing assembly and the drilling tool, so that the core bushing assembly and the drilling tool can be simultaneously lowered and recovered. During the drilling operation, the number of times of drilling and running the drill bit is reduced, the project progress is greatly improved, and the construction cost is reduced.

[0030] Specifically, Figure 1 A schematic diagram of an anti-wear core packing structure for deep-water marine drilling provided in an embodiment of the present application, Figure 2 This is a schematic structural diagram of an axial locking unit 2 in an anti-wear packing for deep-water marine drilling provided in an embodiment of the present application, as shown in FIG. Figure 1 、 Figure 2 As shown, the bushing assembly includes a bushing body 1, a plurality of axial locking units 2 spaced apart on the outer circumferential wall of the bushing body 1, and a recovery ring 3 disposed on the top of the inner circumferential wall of the bushing body 1. The axial locking unit 2 includes an axial locking pin 201 that can move horizontally toward the center of the bushing body 1. The outer circumferential wall of the bushing body 1 is also provided with a plurality of wellhead anti-rotation units 9 for locking the wellhead.

[0031] The bushing body 1 is a cylindrical body that passes through from top to bottom and is made entirely of wear-resistant metal. Axial locking units 2 are provided on the inner circumferential wall of the bushing body 1, and there are multiple of them. When the axial locking pin 201 extends toward the center of the bushing body 1, it can be axially locked with the retractable assembly to prevent longitudinal separation between the retractable assembly and the bushing body 1. The recovery ring 3 is provided on the inner circumferential wall of the top of the bushing body 1. It is mainly used for engaging the bottom of the recovery ring 3 with the top of the retractable assembly when recovering the bushing body 1. When the retractable assembly is raised, it can drive the bushing body 1 to rise and separate from the inner wall of the wellbore.

[0032] Further, Figure 3 A schematic diagram of the structure of a wear-resistant core lowering tool 4 and a locking blade 5 for deep-water marine drilling provided in an embodiment of the present application is shown in FIG. Figure 3 As shown, the retraction and deployment assembly includes a lowering tool 4 that passes through the core bushing body 1 and is used to connect the drilling tool at the bottom. The outer periphery of the lowering tool 4 is provided with locking leaves 5 that are equal in number to the axial locking pins 201 and are positioned opposite to each other. The outer sides of the locking leaves 5 are laterally provided with through grooves 501 that match the axial locking pins 201. The tops of the locking leaves 5 are provided with a fitting surface that matches the bottom of the recovery ring 3.

[0033] During actual use, the top of the lowering tool 4 is connected to the drill pipe and rotates together with the drill pipe, and the bottom of the lowering tool 4 is connected to the drilling tool. The way in which the lowering tool 4 is connected to the drilling tool includes but is not limited to threaded connection, etc., and no specific restrictions are made here. The locking leaves 5 are mainly used to connect the core packing body 1. The locking leaves 5 are vertically arranged on the outer periphery of the lowering tool 4. They have a certain height and are fixed to the lowering tool 4 to form a whole. As an optional embodiment, in this application, the number of axial locking units 2 and locking leaves 5 are both three, the three groups of axial locking units 2 are equidistantly arranged, and the angles between any two adjacent locking leaves 5 in the three locking leaves 5 are equal.

[0034] When the bushing body 1 is lowered, the axial locking pin 201 extends toward the center of the bushing body 1 and the extended end of the axial locking pin 201 is located in the through groove 501. The through groove 501 is arranged horizontally, which can axially lock the locking leaf 5 and the bushing body 1 to prevent the bushing body 1 from falling off longitudinally during the lowering process. When the bushing body 1 is lowered into place, the drill pipe is rotated to drive the running tool 4 and the locking leaf 5 to rotate together, and the through groove 501 is circumferentially displaced, and the axial locking pin 201 is out of the through groove 501. At this time, the lock between the locking leaf 5 and the bushing body 1 is released, and the drill pipe drives the running tool 4 to continue to be lowered and drilling work is carried out. The wellhead anti-rotation unit 9 can circumferentially lock the bushing body 1 and the high-pressure wellhead head, which can prevent the bushing body 1 and the running tool 4 from rotating together when the running tool 4 rotates, causing unlocking failure.

[0035] After the drilling work is completed, when the bushing body 1 is recovered, the drill rod is directly lifted up, and the drill rod drives the lowering tool 4 and the drilling tool at the bottom of the lowering tool 4 to rise together. When the lowering tool 4 rises to a certain height, the top of the locking leaf 5 contacts the bottom of the recovery ring 3, and the two are locked and fixed with each other. The drill rod is continued to be lifted up to bring out the bushing body 1.

[0036] For further information, see Figure 2 The bushing body 1 is provided with first accommodating grooves 6 , which are equal in number to the axial locking units 2 and transversely penetrate the circumferential wall of the bushing body 1 , and each first accommodating groove 6 is provided with a group of axial locking units 2 .

[0037] In the absence of external force, the axial locking unit 2 is located within the first receiving groove 6. When the bushing body 1 needs to be locked with the lowering tool 4, one end of the axial locking pin 201 is pushed out of the first receiving groove 6 laterally toward the center of the bushing body 1. The drill rod is then rotated, driving the lowering tool 4 and the locking leaf 5 to lock the axial locking pin 201 with the through-type groove 501. In this application, the axial locking pin 201 is configured to automatically retract. When the bushing body 1 is lowered into place, the lock between the locking leaf 5 and the axial locking pin 201 is released, allowing the axial locking pin 201 to automatically retract into the first receiving groove 6.

[0038] Specifically, a step portion 601 is provided at one end of the first receiving groove 6 close to the center of the bushing body 1 , and a first return spring 602 is transversely provided on the step portion 601 for driving the axial locking pin 201 to retract into the first receiving groove 6 .

[0039] In this application, the longitudinal section of the axial locking pin 201 is T-shaped. Figure 2 Taking perspective as an example, the axial locking pin 201 includes a vertical end and a horizontal end. The vertical end is always displaced in the first accommodating groove 6, and the horizontal end extends out of the first accommodating groove 6 and contacts the through-type groove 501. One end of the first return spring 602 is fixedly arranged on the step surface of the step portion 601, and the other end is fixedly connected to the side of the vertical end facing the horizontal end. When the axial locking pin 201 is located in the first accommodating groove 6, the first return spring 602 is in a stretched state. When the axial locking pin 201 is locked with the through-type groove 501, the first return spring 602 is in an extruded state. When the lock between the axial locking pin 201 and the through-type groove 501 is released, the automatic return property of the first return spring 602 will drive the axial locking pin 201 to automatically retract into the first accommodating groove 6.

[0040] The setting of the step portion 601 is not only used to fix the first return spring 602 and serve as the reaction point of the return spring 602, but also can limit the extension path of the axial locking pin 201, preventing the axial locking pin 201 from extending too far and falling out of the first accommodating groove 6.

[0041] Furthermore, a first stopper 603 is provided at one end of the first receiving groove 6, away from the stepped portion 601, for pushing the axial locking pin 201 out of the first receiving groove 6. The outer annular surface of the first stopper 603 is threadedly connected to the inner wall of the first receiving groove 6. The first stopper 603 has a certain thickness, and its wheel surface is provided with external threads, while the corresponding position on the inner wall of the first receiving groove 6 is provided with internal threads. When the axial locking pin 201 needs to be extended from the first receiving groove 6, the first stopper 603 is rotated to push the axial locking pin 201 out of the first receiving groove 6 toward the center of the bushing body 1. After the axial locking pin 201 is locked with the through-groove 501, the first stopper 603 is rotated in the opposite direction to return to its original position, thereby reserving space for the automatic retraction of the axial locking pin 201. To facilitate the rotation of the first stopper 603, a groove is provided on the side of the first stopper 603 away from the axial locking pin 201, thereby facilitating connection with an external tightening tool.

[0042] As an optional embodiment, a retaining ring 604 is provided on the inner wall of the end of the first accommodating groove 6 away from the first baffle 603. The outer circumferential wall of the retaining ring 604 is connected to the inner circumferential wall of the first accommodating groove 6. When the first baffle 603 returns to its position, the moving distance of the first baffle 603 can be limited to prevent the first baffle 603 from falling out of the first accommodating groove 6.

[0043] Further, Figure 5 A schematic structural diagram of a circumferential locking pin 701 in an anti-wear packing for deep-water marine drilling is provided in an embodiment of the present application. Figure 1 、 Figure 3 、 Figure 5 As shown, a second accommodating groove 7 is provided below each first accommodating groove 6. The second accommodating groove 7 extends transversely through the circumferential wall of the bushing body 1. Each second accommodating groove 7 is provided with an annular locking pin 701, which extends out of the second accommodating groove 7 toward the center of the bushing body 1. The number and orientation of the second accommodating grooves 7 are identical to those of the first accommodating grooves 6, and the second accommodating grooves 7 are located directly below the first accommodating grooves 6. Therefore, the number of annular locking pins 701 is also equal to that of the axial locking units 2. In one embodiment of the present application, there are three annular locking pins 701. After the bushing body 1 and the lowering tool 4 are axially locked, the annular locking pin 701 is installed in the second accommodating groove 7, with one end of the annular locking pin 701 extending out of the second accommodating groove 7 toward the center of the bushing body 1.

[0044] In this application, the annular locking pin 701 is primarily used to circumferentially lock the bushing body 1 to the lowering tool 4, preventing abnormal rotation between the bushing body 1 and the lowering tool 4 during the lowering process, which could cause the bushing body 1 to fall off. Therefore, in this application, the locking leaf 5 is provided with an annular locking groove 502, and the end of the annular locking pin 701 extending from the second receiving groove 7 is located within the annular locking groove 502.

[0045] Due to the positioning of the annular locking pin 701 and the axial locking pin 201, when the axial locking pin 201 is located within the through-groove 501, each annular locking groove 502 will also be directly opposite the second receiving groove 7, and the end of the annular locking pin 701 extending from the second receiving groove 7 will directly enter the annular locking groove 502. At this point, the bushing body 1 and the running tool 4 are both locked in the annular and axial directions. The bushing body 1 is then lowered. After the bushing body 1 is lowered, the running tool 4 is rotated, disengaging the axial locking pin 201 from the through-groove 501. At this point, the rotation of the running tool 4 directly severs the annular locking pin 701, completely unlocking the bushing body 1 and the running tool 4. The running tool 4 continues to descend along with the drill pipe, driving the drilling tool downward.

[0046] Further, Figure 4 A schematic diagram of the structure of a wellhead anti-rotation unit in an anti-wear patching core for deep-water marine drilling is provided in an embodiment of the present application. Figure 1 、 Figure 4 As shown, a plurality of third accommodating grooves 8 are provided on the bushing body 1. The third accommodating grooves 8 are radially symmetrically arranged along the bushing body 1, and a wellhead anti-rotation unit 9 is provided in each third accommodating groove 8. The wellhead anti-rotation units 9 are distributed on the outer periphery of the bushing body 1 and are mainly used to abut against the inner wall of the high-pressure wellhead and lock circumferentially with the high-pressure wellhead to prevent the bushing body 1 from rotating together with the lowering tool 4 at the high-pressure wellhead.

[0047] Specifically, the wellhead anti-rotation unit 9 includes an anti-rotation pin 901 extending out of the third receiving groove 8 in a direction away from the center of the bushing body 1 , and a second return spring 902 is laterally provided at one end of the anti-rotation pin 901 close to the center of the bushing body 1 .

[0048] In the present application, in the absence of external force, the second return spring 902 is in a stretched state, and pushes the anti-rotation pin 901 out of the third accommodating groove 8 in a direction away from the center of the core packing body 1. In the present application, the end of the anti-rotation pin 901 extending out of the third accommodating groove 8 is pointed, and its outer periphery has a certain slope. When the slope surface is compressed, the anti-rotation pin 901 will retract into the third accommodating groove 8. When the core packing body 1 descends, the relative displacement between the core packing body 1 and the wellhead forces the anti-rotation pin 901 to retract a part into the third accommodating groove 8, and the second return spring 902 is in an extruded state. Therefore, the second return spring 902 will also have the rebound force to push the anti-rotation pin 901 out of the third accommodating groove 8. Based on this structure, the core packing body 1 and the high-pressure wellhead can be firmly locked in an annular direction.

[0049] Furthermore, multiple wellhead anti-drop units 10 extending from the outer periphery of the core bushing body 1 can be detachably provided. The wellhead anti-drop units 10 are used in conjunction with the wellhead anti-rotation units 9. The portion of the wellhead anti-drop unit 10 extending from the core bushing body 1 is used to abut against the inner wall of the high-pressure wellhead head and cooperate with the locking groove of the high-pressure wellhead head to achieve axial locking of the core bushing body 1 and the high-pressure wellhead head, preventing the core bushing body 1 from longitudinally displacing within the well. In this application, the wellhead anti-drop unit 10 is also a consumable component. When the core bushing body 1 is recovered, the rising of the core bushing body 1 will cause the wellhead anti-drop unit 10 to be disconnected. The specific form of the wellhead anti-drop unit 10 is not specifically limited in this application, and it only needs to be able to engage with the locking groove of the high-pressure wellhead head.

[0050] Furthermore, a second retaining ring 903 is provided at one end of the third receiving groove 8 away from the second return spring 902. A through hole is provided in the middle of the second retaining ring 903, which is consistent with the shape of the outer end of the anti-rotation pin 901 and is used for the outer end of the anti-rotation pin 901 to pass through. In one embodiment of the present application, the outer circumference of the second retaining ring 903 is provided with an external thread, and the relative position of the third receiving groove 8 is provided with an external thread to achieve a threaded connection between the second retaining ring 903 and the third receiving groove 8. The end of the anti-rotation pin 901 that extends out of the third receiving groove 8 is the outer end of the anti-rotation pin 901. The pointed shape causes the diameter of the anti-rotation pin 901 to increase from the outside to the inside. The through hole on the second retaining ring 903 only accommodates a portion of the outer end of the anti-rotation pin 901, which can prevent the anti-rotation pin 901 from slipping out of the third receiving groove 8.

[0051] Furthermore, based on the threaded connection between the second retaining ring 903 and the third accommodating groove 8, in the present application, in order to increase the friction between the second retaining ring 903 and the third accommodating groove 8 and prevent the second retaining ring 903 and the third accommodating groove 8 from rotating relative to each other, as an optional embodiment, an elastic retaining ring is also provided on the outer periphery of the second retaining ring 903. Specifically, the width of the external thread on the second retaining ring 903 is smaller than the width of the outer circumference of the second retaining ring 903, so as to reserve a partial blank area on the outer circumference of the second retaining ring 903 for setting the elastic retaining ring.

[0052] Furthermore, a first inclined surface 503 is provided on the top of the locking leaf 5, and a second inclined surface 301 matching the first inclined surface 503 is provided on the bottom of the recovery ring 3. Figure 6 A schematic structural diagram of the first inclined surface 503 and the second inclined surface 301 of an anti-wear filler core for deep-water marine drilling provided in an embodiment of the present application is shown in FIG. Figure 6 As shown, the first inclined surface 503 is a descending inclined surface from the inside to the outside. When the lowering tool 4 rises to a certain level, the first inclined surface 503 contacts and engages with the second inclined surface 301. The lowering tool 4 continues to rise, and the bushing body 1 is brought out of the high-pressure wellhead.

[0053] Furthermore, a sealing ring is provided on the outer periphery of the top of the core packing body 1 to prevent rock cuttings from entering the annular gap between the core packing body 1 and the high-pressure wellbore head during drilling.

[0054] The use process of the anti-wear core bushing in the present application is as follows: the tool 4 is lowered through the core bushing body 1, and then the drill pipe is connected and the drilling tool is lowered. First, the through groove 501 on the locking leaf 5 on the lowering tool 4 is locked with the axial locking pin 201, and then the annular locking pin 701 is installed into the annular locking groove 502 on the locking leaf 5. Then, the core bushing body 1 is lowered. After it is lowered into place, the anti-rotation unit is locked circumferentially with the high-pressure wellhead, and the anti-drop unit is locked axially with the high-pressure wellhead. Then, the drill pipe is rotated and lowered. The tool 4 rotates accordingly, the annular locking pin 701 is cut off, and the axial locking pin 201 is out of the through groove 501. At this point, the lock between the bushing body 1 and the lowering tool 4 is released, and the drill pipe drives the lowering tool 4 and the drilling tool to continue to descend, and the drilling work begins. After the drilling work is completed, the drill pipe drives the lowering tool 4 to rise until the first inclined surface 503 on the locking leaf 5 engages with the second inclined surface 301 of the recovery ring 3. The tool continues to rise, the wellhead anti-fall unit 10 is cut off, and the bushing body 1 is recovered.

[0055] The anti-wear core bushing in the present application is provided with an axial locking unit 2 that can cooperate with the locking leaf 5 inside the core bushing body 1, so that the core bushing body 1 can be stably connected to the lowering tool 4 during lowering. After the lowering is completed, the core bushing body 1 and the lowering tool 4 are unlocked by rotation to continue lowering the drilling tool. After the drilling is completed, the core bushing body 1 and the drilling tool are recovered by the engagement between the recovery ring 3 and the locking leaf 5. By providing the wellhead anti-rotation unit 9 and the wellhead anti-fall unit 10, the stable axial and circumferential locking of the core bushing body 1 and the high-pressure wellhead head can be ensured, and abnormal displacement between the core bushing body 1 and the high-pressure wellhead head can be prevented, thereby ensuring the lowering stability and safety. The anti-wear core bushing in the present application can achieve the synchronous retraction and release of the recovered core bushing body 1 and the drilling tool, without the need to repeatedly raise and lower the drill during the drilling process, saving a lot of construction time, and also greatly reducing the construction cost.

[0056] In the description of this application, it should be noted that the terms "upper" and "lower" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this application. Unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be internal communication between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to the specific circumstances.

[0057] It should be noted that, in this application, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprising a ..." does not exclude the presence of other identical elements in the process, method, article or device comprising the element.

[0058] The foregoing is merely a list of specific embodiments of the present application, intended to enable those skilled in the art to understand or implement the present application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application is not limited to the embodiments shown herein, but is intended to conform to the broadest scope consistent with the principles and novel features of the present application.

Claims

1. An anti-wear bushing for deep-water marine drilling, characterized in that: include, A core packing assembly, comprising a core packing body (1), a plurality of axial locking units (2) spaced apart on the inner circumferential wall of the core packing body (1), and a recovery ring (3) disposed on the top of the inner circumferential wall of the core packing body (1), wherein the axial locking unit (2) comprises an axial locking pin (201) that can move horizontally toward the center of the core packing body (1), and a plurality of wellhead anti-rotation units (9) for locking the wellhead are further disposed on the outer circumferential wall of the core packing body (1); A retractable assembly, comprising a lowering tool (4) passing through the bushing body (1) and having a bottom for connecting to a drilling tool, wherein the outer periphery of the lowering tool (4) is provided with locking leaves (5) equal in number to and opposite in position to the axial locking pin (201), the outer sides of the locking leaves (5) are laterally provided with through grooves (501) matching the axial locking pin (201), and the tops of the locking leaves (5) are provided with a fitting surface matching the bottom of the recovery ring (3); The bushing body (1) is provided with first accommodating grooves (6) having the same number as the axial locking units (2) and extending transversely through the circumferential wall of the bushing body (1), and each of the first accommodating grooves (6) is provided with a group of the axial locking units (2); A second accommodating groove (7) is provided below each of the first accommodating grooves (6), the second accommodating grooves (7) extending transversely through the circumferential wall of the bushing body (1), and an annular locking pin (701) is provided in each of the second accommodating grooves (7), the annular locking pin (701) extending out of the second accommodating groove (7) in a direction close to the center of the bushing body (1); An annular locking groove (502) is provided on the locking leaf (5), and one end of the annular locking pin (701) extending out of the second accommodating groove (7) is located in the annular locking groove (502).

2. The wear-resistant bushing for deep-water marine drilling according to claim 1, characterized in that: A step portion (601) is provided at one end of the first accommodating groove (6) close to the center of the bushing body (1), and a first return spring (602) is transversely provided on the step portion (601) for driving the axial locking pin (201) to retract into the first accommodating groove (6).

3. The wear-resistant bushing for deep-water marine drilling according to claim 2, characterized in that: An end of the first accommodating groove (6) away from the step portion (601) is provided with a first baffle (603) for pushing the axial locking pin (201) out of the first accommodating groove (6), and an outer annular surface of the first baffle (603) is threadedly connected to the inner wall of the first accommodating groove (6).

4. The anti-wear bushing for deep-water marine drilling according to claim 1, characterized in that: A plurality of third accommodating grooves (8) are provided on the core-bushing body (1), the third accommodating grooves (8) are radially symmetrically arranged along the core-bushing body (1), and a wellhead anti-rotation unit (9) is provided in each of the third accommodating grooves (8).

5. The anti-wear bushing for deep-water marine drilling according to claim 4, characterized in that: The wellhead anti-rotation unit (9) comprises an anti-rotation pin (901) extending out of the third accommodating groove (8) in a direction away from the center of the bushing body (1), and a second return spring (902) is transversely provided at one end of the anti-rotation pin (901) close to the center of the bushing body (1).

6. The anti-wear bushing for deep-water marine drilling according to claim 5, characterized in that: A second retaining ring (903) is provided at one end of the third accommodating groove (8) away from the second return spring (902), and a through hole having the same shape as the outer end of the anti-rotation pin (901) is provided in the middle of the second retaining ring (903) for the outer end of the anti-rotation pin (901) to pass through.

7. The anti-wear bushing for deep-water marine drilling according to claim 1, characterized in that: A first inclined surface (503) is provided on the top of the locking leaf (5), and a second inclined surface (301) matching the first inclined surface (503) is provided on the bottom of the recovery ring (3).

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