CN112324377B - Downhole operation tool and method for permanently abandoned well of deep sea drillless machine - Google Patents

Abstract

The application relates to the technical field of ocean engineering, in particular to a downhole operation tool and an operation method for permanently abandoning a well in a deep sea without a drilling machine, wherein the downhole operation tool comprises an injection assembly, a packing assembly, a spraying assembly, an anchoring assembly I, a rotary cutting assembly, an anchoring assembly II and a continuous oil pipe which are connected in sequence at first; the application solves the problems of more construction procedures, long operation time, high cost, complex operation, high operation cost and the like in the prior art, completes the perforation operation of the production oil pipe through the injection assembly, and opens the pore canal between the oil sleeve annulus and the inner cavity of the production oil pipe; the annular cutting operation of the wall of the production oil pipe is completed through the rotary cutting assembly; the positioning and the partition interval are reinforced through the outward expansion structure, the anchoring claw teeth also play a role in positioning and reinforcing, the underground operation tool for permanently abandoning the well of the deep sea drillless machine is used, the operation can be completed by three steps of cement squeezing operation, the operation time is greatly shortened, the operation time and the cost are reduced, the operation is flexible, and the operation cost is low.

Description

Downhole operation tool and method for permanently abandoned well of deep sea drillless machine

Technical Field

The application relates to the technical field of ocean engineering, in particular to a downhole operation tool and an operation method for permanently abandoning a well in a deep sea without a drilling machine.

Background

The marine well abandoning operation may be classified into a well abandoning operation by a well drilling ship and a well abandoning operation by a no-well drilling ship according to whether a well drilling ship or other mobile well drilling device is used in the well abandoning operation. Conventional ocean deepwater well abandoning operations often adopt a drilling ship for operation, wherein the used facilities are mainly the drilling ship, the ship is provided with corresponding drilling frames, winches and various auxiliary facilities, and underground facilities such as oil pipes, casings and the like can be taken out during the well abandoning operation. The well abandoning operation without the drilling ship is carried out by adopting a specially designed engineering ship and various special water and underwater equipment, compared with the well abandoning operation without the drilling ship, the oil pipe in the well does not need to be taken out, and the engineering ship does not have a large drilling frame, so that the size of the ship body is much smaller, and the operation cost is lower. Because no drilling ship is used for operation, no drilling ship with scarce resources is needed, and the economic benefit is obvious, the technology has been rapidly developed abroad in recent years, and has wide application in ocean deepwater well abandoning operation and various well repairing operations. At present, the application of the technology in China is still blank, and with the development of ocean oil and gas resources in China, the number of operations of various well abandoning, well repairing and yield increasing measures is continuously increased, and by adopting the technology, not only can the scarce deep water platform resources in China be saved, but also great economic benefits are achieved.

The conventional drilling-free ocean well abandoning operation uses steel wires as media to put into bridge plugs, perforation and cutting tools, different tools are connected to start the steel wire ropes once in each operation, the construction process is more, physical cutting is adopted for cutting the oil pipes, and the subsequent recovery and treatment are more troublesome; the steel wire rope is used as a medium, and a circulating channel is required to be established through an underwater control system, a christmas tree, a balancing weight system and the like. And each working procedure is completed, the next time of obtaining the underground tools is needed, at least seven tools are lowered in the whole well abandoning process, the working time is long, and the cost is high. The drillless well abandoning operation is more flexible to operate and lower in operation cost by taking the coiled tubing as a medium.

Disclosure of Invention

The application mainly aims to provide a downhole operation tool and an operation method for permanently abandoning a well in a deep sea without a drilling machine, so as to solve the problems of more construction procedures, long operation time, high cost, complex operation, high operation cost and the like in the prior art.

In order to achieve the above purpose, the present application adopts the following technical scheme:

the downhole operation tool for permanently abandoning a well in a deep sea without a drilling machine is arranged at the tail end of a continuous oil pipe and used, and comprises an injection assembly, a packing assembly, a spraying assembly, an anchoring assembly I, a rotary cutting assembly and an anchoring assembly II which are connected in sequence at first; the upper part of the injection assembly is connected with a continuous oil pipe, and injection channels which are communicated with each other are arranged in the injection assembly, the packing assembly, the injection assembly, the anchoring assembly I, the rotary cutting assembly and the anchoring assembly II; the continuous oil pipe is communicated with the injection channel;

the injection assembly comprises an injection nozzle body, an injection port is formed in one end of the injection nozzle body, and a ball seat I is arranged in the injection nozzle body;

the packing assembly comprises a packer body and an outward expansion structure connected to the packer body;

the injection assembly comprises an injection short circuit body, a communication hole is formed in the side wall of the injection short circuit body, a nozzle is arranged in the communication hole, a shearing pin I is arranged in an injection channel of the injection assembly, a sliding sleeve I is further arranged in the injection channel of the injection assembly, the sliding sleeve I is positioned above the shearing pin I, and the communication hole in the side wall of the injection short circuit body is plugged by the sliding sleeve I;

the anchoring assembly I and the anchoring assembly II both comprise an anchoring body, a communication hole is formed in the side wall of the anchoring body, an anchoring claw tooth is arranged in the communication hole, the claw tooth direction of the anchoring claw tooth is outwards, and a ball seat II is arranged in an injection channel of the anchoring assembly I;

the rotary cutting assembly comprises an upper joint, an outer cylinder, an inner cylinder, a lower joint and a cutting nozzle, wherein the upper joint is connected with the lower joint through the inner cylinder, two ends of the outer cylinder are respectively and rotatably connected to the upper joint and the lower joint, a cavity is arranged between the outer cylinder and the inner cylinder, communication holes are formed in the inner cylinder and the outer cylinder, the communication holes in the outer cylinder deviate by a certain angle, and the cutting nozzle is arranged in the communication holes in the outer cylinder; the injection channel of the rotary cutting assembly is internally provided with a shearing pin II, the sliding sleeve II is arranged in the injection channel of the rotary cutting assembly, the bottom of the sliding sleeve II is propped against the shearing pin II, and the sliding sleeve II seals the communication hole on the side wall of the inner barrel.

Further, bearings are arranged between the outer cylinder and the upper joint and between the outer cylinder and the lower joint.

Further, the injection port is horn-shaped.

Further, the diameter of the injection channel between the ball seat II and the ball seat I is smaller than that of the injection channel above the ball seat II.

Further, the internal diameter of ball seat II is less than the internal diameter of sliding sleeve II, and the internal diameter of ball seat I is less than the internal diameter of sliding sleeve I.

Further, the outward expansion structure is a rubber structure.

Further, injection assembly one end has the internal thread of connection, and coiled tubing one end has the external thread of connection, seals and separates subassembly, injection assembly, anchor subassembly I, rotatory cutting assembly and anchor subassembly II all one end has the internal thread of connection, and the other end has the external thread of connection, from the bottom up, injection assembly, seals and separates subassembly, injection assembly, anchor subassembly, rotatory cutting assembly, anchor subassembly II and coiled tubing threaded connection in proper order.

An operation method using the downhole operation tool comprises the following steps:

s1: the underground operation tool is lowered into the production oil pipe through the continuous oil pipe, high-pressure cement paste is pumped into the injection channel through the continuous oil pipe, the outward expansion structure is expanded under the action of pressure, and the anchoring claw teeth are in an anchoring state under the action of the internal pressure of the pipe;

s2: the cement paste is extruded into the stratum through the bottom injection opening under the high pressure; stopping the pump when the length of the extruded cement plug meets the requirement, lifting the working tool for waiting for solidification, injecting liquid into the ground for pressure test after waiting for solidification is finished, applying pressure through a continuous oil pipe injection head, detecting the top surface strength of the side, and sealing the cement plug of the first section after the strength is qualified;

s3: the position of a second section of cement plug is lifted on the working tool, a steel ball I is put into the working tool, pumping pressure is improved, a sliding sleeve I breaks through a shearing pin I under the action of internal pressure in an injection channel, the shearing pin I falls into the position of a ball seat I, and a communication hole on the side wall of the injection assembly is opened at the moment; pumping high-pressure sand blasting liquid into the injection channel, spraying the high-pressure sand blasting liquid from a nozzle to puncture the pipe wall of the production oil pipe, forming a punching hole on the pipe wall of the production oil pipe, wherein the outward expanding structure and the anchoring claw teeth are in a working state under the action of pressure in the process;

s4: pumping cement slurry pre-fluid into the injection channel, isolating the first section cement plug from the second section cement plug through the pre-fluid, injecting the second section cement plug, injecting the cement plug into the oil sleeve annulus between the production oil pipe and the sleeve from the punching hole besides the inner cavity of the production oil pipe, lifting the continuous oil pipe for waiting for solidification after the injection is finished, testing pressure and probing the top surface of the cement plug after the waiting for solidification is finished, and sealing the second section cement plug after the cement plug is qualified;

s5: lifting the working tool to the position of a third section of cement plug, putting a steel ball II into the working tool, improving pumping pressure to build pressure, breaking a shear pin II by a sliding sleeve II under the action of the internal pressure of an injection channel, falling into a ball seat II of an anchoring component I, opening a communication hole on the side wall of an inner cylinder, pumping high-pressure sand blasting liquid into the injection channel, spraying the high-pressure sand blasting liquid from a cutting nozzle, cutting a pipe column to be cut by means of jet impact force, and simultaneously, applying a reaction force of the jet impact force to an outer cylinder, wherein the outer cylinder is connected with the inner cylinder by a bearing, and the outer cylinder rotates relative to the inner cylinder to realize cutting of a production oil pipe; and after the cutting is completed, the cut upper production oil pipe is lifted out.

S6: pumping cement slurry pre-liquid into the injection channel, isolating the second section cement plug from the third section cement plug through the pre-liquid, injecting the third section cement plug inwards, filling the whole shaft cavity of the target well section by the cement plug at the moment, finishing extrusion injection after the length of the extrusion cement plug meets the requirement, waiting for solidification by an upward lifting operation tool, testing pressure and probing the top surface of the cement plug after the solidification is finished, and finishing sealing of the third section cement plug after the pressure test is qualified;

s7: finally, recovering the wellhead device to finish the whole well abandoning process.

The application has the following beneficial effects:

(1) The underground operation tool is provided with the injection assembly, the nozzle is plugged through the sliding sleeve I, the steel ball I drives the sliding sleeve I to fall, the opening of the nozzle is controlled, the wall of the oil pipe is broken through the nozzle, the cement plug is extruded into the annular space between the production oil pipe and the casing pipe from the position of the breakdown hole, the controllability is high, the cement plug can be injected at any proper height according to actual requirements, and the controllability is high;

(2) The downhole operation tool is provided with a rotary cutting assembly, a sliding sleeve II can be controlled through a steel ball II, an inner cylinder communication hole of the rotary cutting assembly is opened, the communication hole on an outer cylinder is inclined by a certain angle, high-pressure sand blasting liquid is pumped into an injection channel and is sprayed out from a nozzle, a pipe column to be cut is cut off by means of jet impact force, and meanwhile, the outer cylinder rotates relative to the inner cylinder by means of the reaction force of the jet impact force, so that cutting of a production oil pipe is realized, and an annular notch is formed on the pipe wall of the production oil pipe;

(3) The underground operation tool can be completed by three cement injection operations, the operation time is greatly shortened, the operation time and the cost are reduced, the operation is flexible, and the operation cost is low.

Drawings

FIG. 1 is a schematic diagram of the structure of the present application;

FIG. 2 is a schematic illustration of an injection assembly configuration;

FIG. 3 is a schematic illustration of a packing assembly configuration;

FIG. 4 is a schematic illustration of a spray assembly configuration;

FIG. 5 is a schematic view of a nozzle position;

FIG. 6 is a schematic view of an anchor assembly I;

FIG. 7 is a schematic view of a rotary cutting assembly;

FIG. 8 is a schematic diagram of a cutting nozzle distribution;

FIG. 9 is a schematic view of an anchor assembly II;

FIG. 10 is a schematic illustration of the initial position of the first and second sliding sleeves I and II;

FIG. 11 is a schematic diagram showing the positions of the sliding sleeve I and the sliding sleeve II and the extrusion state after the steel ball I is put into the device;

FIG. 12 is a schematic view of the positions of the sliding sleeve I and the sliding sleeve II and the extrusion state after the steel ball II is put into the device;

in the figure: 1. an injection assembly; 11. an injection nozzle body; 12. ball seat I; 13. an injection port; 2. a packing assembly; 21. a packer body; 22. an outward expansion structure; 3. a jetting assembly; 31. spraying a short circuit body; 32. a nozzle; 33. shearing a pin I; 4. an anchor assembly I; 41. an anchor body; 42. anchoring the pawl tooth; 43. ball seat II; 5. a rotary cutting assembly; 51. an upper joint; 52. an outer cylinder; 53. an inner cylinder; 54. a lower joint; 55. a cutting nozzle; 56. shearing a pin II; 6. an anchor assembly II; 7. a coiled tubing; 8. a sliding sleeve II; 9. a sliding sleeve I; 10. a steel ball I; 101. a steel ball II; 102. a production tubing; 103. a sleeve; 104. an oil casing annulus packer.

Detailed Description

The application is further described below with reference to the accompanying drawings.

As shown in fig. 1-9, the downhole tool for deep sea drilling machine-free permanent well abandonment according to the application comprises an injection assembly 1, a packing assembly 2, a jetting assembly 3, an anchoring assembly i 4, a rotary cutting assembly 5, an anchoring assembly ii 6 and a coiled tubing 7 which are connected in sequence at first; injection assembly 1, packer assembly 2, injection assembly 3, anchor assembly I4, rotary cutting assembly 5, anchor assembly II 6 and coiled tubing 7 are provided with mutually communicating injection passages.

As shown in fig. 2, the injection assembly 1 comprises an injection nozzle body, one end of the injection nozzle body is provided with an injection port 13, the injection port is in a horn shape, and the injection nozzle body is internally provided with a ball seat I12; the injection nozzle body is connected with the packing assembly through threads.

As shown in fig. 3, the packing assembly includes a packer body 21 and a flaring structure 22 attached to the packer body; the outward expansion structure is a rubber structure, and can be outwards expanded under the action of small water pressure, so that the sealing of a cavity between the working tool and the production oil pipe is realized.

As shown in fig. 4 and 5, the injection assembly comprises an injection short circuit body 31, a communication hole is formed in the side wall of the injection short circuit body, a nozzle 32 is detachably arranged in the communication hole, a shearing pin I33 is arranged in an injection channel of the injection assembly, a sliding sleeve I9 is also arranged in the injection channel of the injection assembly, the sliding sleeve I is positioned above the shearing pin I, and the communication hole in the side wall of the injection short circuit body is blocked by the sliding sleeve I; the injection assembly is connected with the packing assembly through threads, sand blasting liquid is pumped into the injection pipeline, high-speed jet flow sprayed by the nozzle is utilized to break through the wall of the production oil pipe, and a channel between the inner cavity of the production oil pipe and the annular space of the oil sleeve is opened, so that the hydraulic perforation process is completed.

As shown in fig. 6 and 9, the anchor assembly i 4 and the anchor assembly ii 6 each include an anchor body 41, a communication hole is formed on a side wall of the anchor body, an anchor pawl 42 is installed in the communication hole, the pawl of the anchor pawl faces outwards, and a ball seat ii 43 is provided in an injection channel of the anchor assembly i 4; after the pressure in the injection channel is raised, the anchor claw is opened and anchored on the inner wall of the production oil pipe, so that on one hand, the centering effect of the rotary cutting assembly is achieved, on the other hand, the torque uploading of the rotary cutting assembly can be prevented, the coiled tubing is damaged, and the positioning effect of the rotary cutting assembly can be achieved.

The diameter of the injection channel between the ball seat II and the ball seat I is smaller than the injection channel above the ball seat II, the inner diameter of the ball seat II is smaller than the inner diameter of the sliding sleeve II, the inner diameter of the ball seat I is smaller than the inner diameter of the sliding sleeve I, the diameter of the steel ball I is smaller than the diameter of the steel ball II, and the steel ball I can smoothly pass through the sliding sleeve II and the ball seat II when falling down, and directly drives the sliding sleeve I to fall down to the position of the ball seat I.

As shown in fig. 7 and 8, the rotary cutting assembly 5 comprises an upper joint 51, an outer cylinder 52, an inner cylinder 53, a lower joint 54 and a cutting nozzle 55, wherein the upper joint and the lower joint are connected through the inner cylinder, two ends of the outer cylinder are respectively and rotatably connected to the upper joint and the lower joint, and a bearing is arranged between the outer cylinder and the upper joint as well as between the outer cylinder and the lower joint, so that the rotary cutting assembly is convenient and smooth to rotate; a cavity is arranged between the outer cylinder and the inner cylinder, communicating holes are arranged on the inner cylinder and the outer cylinder, the communicating holes on the outer cylinder deviate by a certain angle, and a cutting nozzle is arranged in the communicating holes of the outer cylinder; the injection channel of the rotary cutting assembly is internally provided with a shearing pin II 56, the sliding sleeve II 8 is arranged in the injection channel of the rotary cutting assembly, the bottom of the sliding sleeve II is propped against the shearing pin II, and the sliding sleeve II seals the communication hole on the side wall of the inner barrel.

Injection assembly one end has the connection internal screw thread, coiled tubing one end has the connection external screw thread, seal and separate subassembly, spray the subassembly, anchor subassembly I, rotatory cutting assembly and anchor subassembly II all one end has the connection internal screw thread, the other end has the connection external screw thread, from the bottom up, injection assembly, seal and separate subassembly, spray the subassembly, anchor subassembly, rotatory cutting assembly, anchor subassembly II and coiled tubing threaded connection in proper order, of course, the connection constitution of above-mentioned each part also is not limited to threaded connection, any detachable connection form that can convenient operation can all.

A method of operation using the above-described downhole tool for deep sea drilling rig-less permanent well abandonment, as shown in fig. 10-12, comprising the steps of:

the downhole operation tool is lowered into the production oil pipe 102 through the continuous oil pipe, high-pressure cement paste is pumped into the injection channel through the continuous oil pipe, the expansion of the outward expansion structure is realized under the action of pressure, and the anchoring claw teeth are in an anchoring state under the action of the internal pressure of the pipe;

an oil sleeve annular packer is arranged between the production oil pipe and the casing in advance, and expands outwards under the action of internal pressure when the pressure in the injection channel is increased, so that the space between the production oil pipe and the casing is divided, and cement paste is conveniently injected into the stratum subsequently. The oil jacket annulus divider is a pre-installed component on the production tubing and is not the main inventive subject matter and therefore will not be further developed as will be explained herein.

The cement paste is extruded into the stratum through the bottom injection opening under the high pressure; stopping the pump when the length of the extruded cement plug meets the requirement, lifting the working tool for waiting for solidification, injecting liquid into the ground for pressure test after waiting for solidification is finished, applying pressure through a continuous oil pipe injection head, detecting the top surface strength of the side, and sealing the cement plug of the first section after the strength is qualified;

the position of a second section of cement plug is lifted on the working tool, a steel ball I is put into the working tool, pumping pressure is improved, a sliding sleeve I breaks through a shearing pin I under the action of internal pressure in an injection channel, the shearing pin I falls into the position of a ball seat I, and a communication hole on the side wall of the injection assembly is opened at the moment; pumping high-pressure sand blasting liquid into the injection channel, spraying the high-pressure sand blasting liquid from a nozzle to puncture the pipe wall of the production oil pipe, forming a punching hole on the pipe wall of the production oil pipe, wherein the outward expanding structure and the anchoring claw teeth are in a working state under the action of pressure in the process;

pumping cement slurry pre-fluid into the injection channel, isolating the first section cement plug from the second section cement plug through the pre-fluid, injecting the second section cement plug, injecting the cement plug into the oil sleeve annulus between the production oil pipe and the sleeve 103 from the punching hole besides the inner cavity of the production oil pipe, lifting the continuous oil pipe for waiting for solidification after the injection is finished, testing pressure and probing the top surface of the cement plug after the waiting for solidification is finished, and sealing the second section cement plug after the cement plug is qualified;

lifting the working tool to the position of a third section of cement plug, putting a steel ball II 101 into the working tool, improving pumping pressure to build pressure, breaking a shear pin II by a sliding sleeve II under the action of the internal pressure of an injection channel, falling into a ball seat II of an anchoring component I, opening a communication hole on the side wall of an inner cylinder, pumping high-pressure sand blasting liquid into the injection channel, spraying the high-pressure sand blasting liquid from a cutting nozzle, cutting a pipe column to be cut by means of jet impact force, and simultaneously, cutting the pipe column by the reaction force of the jet impact force, wherein the outer cylinder is in a certain torque, and the outer cylinder is in bearing connection with the inner cylinder, so that the outer cylinder rotates relative to the inner cylinder to realize cutting of a production oil pipe, and an annular notch is formed on the production oil pipe; and after the cutting is completed, the cut upper production oil pipe is lifted out.

Pumping cement slurry pre-liquid into the injection channel, isolating the second section cement plug from the third section cement plug through the pre-liquid, injecting the third section cement plug inwards, filling the whole shaft cavity of the target well section by the cement plug at the moment, finishing extrusion injection after the length of the extrusion cement plug meets the requirement, waiting for solidification by an upward lifting operation tool, testing pressure and probing the top surface of the cement plug after the solidification is finished, and finishing sealing of the third section cement plug after the pressure test is qualified;

finally, the well head device comprises a casing pipe head, a pipe mud line hanger, a recovery underwater christmas tree and the like, and the whole well abandoning process is completed.

The application discloses a downhole operation tool and a method for permanently abandoning a well in a deep sea without a drilling machine, which finish the perforation operation of a production oil pipe through a jet assembly and open a pore canal between a stratum and an injection channel; the annular cutting operation of the oil pipe wall is completed through the injection assembly; the positioning and dividing sections are reinforced through the outward expansion structure, the anchoring claw teeth also play a role in positioning and reinforcing, and the combined operation of perforation and cutting is sequentially completed in one pipe column; the sliding sleeve I and the sliding sleeve II are matched with the steel ball I and the steel ball II, so that the communication holes on the side wall of the inner cylinder and the communication holes on the side wall of the injection assembly can be orderly opened, and the breakdown and the cutting of the production oil pipe are facilitated; the whole well abandoning operation is completed by one pipe column descending through the coiled tubing, the auxiliary operation of a drilling derrick and a winch is not needed, the operation is flexible, and the operation cost is lower.

In the description of the present application, it should be noted that the directions or positional relationships indicated by the terms "front end", "rear end", "left and right", "up", "down", "horizontal", etc. are directions or positional relationships based on the drawings, are merely for convenience of describing the present application and simplifying the description, and do not indicate or imply that the apparatus or element to be referred to must have a specific direction, be constructed and operated in the specific direction, and thus should not be construed as limiting the present application.

In the description of the present application, it should also be noted that, unless explicitly specified and limited otherwise, the terms "disposed," "mounted," "connected," "in communication" and "connected" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meaning of the above terms in the present application can be understood by those of ordinary skill in the art according to the specific circumstances.

Of course, the foregoing is merely preferred embodiments of the present application and is not to be construed as limiting the scope of the embodiments of the present application. The present application is not limited to the above examples, and those skilled in the art will appreciate that the present application is capable of equally varying and improving within the spirit and scope of the present application.

Claims (6)

1. The downhole operation tool for permanently abandoning a well in a deep sea without a drilling machine is arranged at the tail end of a continuous oil pipe (7) and is characterized by comprising an injection assembly (1), a packing assembly (2), a jetting assembly (3), an anchoring assembly I (4), a rotary cutting assembly (5) and an anchoring assembly II (6) which are connected in sequence at first; the upper part of the injection assembly is connected with a continuous oil pipe (7), and injection channels which are communicated with each other are arranged in the injection assembly (1), the packing assembly (2), the injection assembly (3), the anchoring assembly I (4), the rotary cutting assembly (5) and the anchoring assembly II (6); the continuous oil pipe (7) is communicated with the injection channel;

the injection assembly (1) comprises an injection nozzle body (11), an injection opening (13) is formed in one end of the injection nozzle body (11), and a ball seat I (12) is arranged in the injection nozzle body (11);

the packing assembly (2) comprises a packer body (21) and an expanding structure (22) connected to the packer body;

the injection assembly (3) comprises an injection short circuit body (31), a communication hole is formed in the side wall of the injection short circuit body (31), a nozzle (32) is arranged in the communication hole, a shearing pin I (33) is arranged in an injection channel of the injection assembly (3), a sliding sleeve I (9) is further arranged in the injection channel of the injection assembly (3), the sliding sleeve I (9) is positioned above the shearing pin I (33), and the communication hole in the side wall of the injection short circuit body (31) is plugged by the sliding sleeve I (9);

the anchoring assembly I (4) and the anchoring assembly II (6) both comprise an anchoring body (41), a communication hole is formed in the side wall of the anchoring body (41), an anchoring claw tooth (42) is arranged in the communication hole, the claw tooth direction of the anchoring claw tooth (42) faces outwards, and a ball seat II (43) is arranged in an injection channel of the anchoring assembly I (4);

the rotary cutting assembly (5) comprises an upper joint (51), an outer cylinder (52), an inner cylinder (53), a lower joint (54) and a cutting nozzle (55), wherein the upper joint (51) and the lower joint (54) are connected through the inner cylinder (53), two ends of the outer cylinder (52) are respectively and rotatably connected to the upper joint (51) and the lower joint (54), a cavity is formed between the outer cylinder (52) and the inner cylinder (53), communication holes are formed in the inner cylinder (53) and the outer cylinder (52), the communication holes in the outer cylinder (52) are inclined at a certain angle, and the cutting nozzle (55) is arranged in the communication holes of the outer cylinder (52); the injection channel of the rotary cutting assembly (5) is internally provided with a shearing pin II (56), the sliding sleeve II (8) is arranged in the injection channel of the rotary cutting assembly (5), the bottom of the sliding sleeve II is propped against the shearing pin II, and the sliding sleeve II seals the communication hole on the side wall of the inner barrel (53);

bearings are arranged between the outer cylinder (52) and the upper joint (51) and between the outer cylinder (52) and the lower joint (54);

injection subassembly (1) one end has the connection internal screw thread, coiled tubing (7) one end has the connection external screw thread, seals and separates subassembly (2), injection subassembly (3), anchor subassembly I (4), rotatory cutting subassembly (5) and anchor subassembly II (6) all one end has the connection internal screw thread, and the other end has the connection external screw thread, from the bottom up, injection subassembly (1), seals and separates subassembly (2), injection subassembly (3), anchor subassembly I (4), rotatory cutting subassembly (5), anchor subassembly II (6) and coiled tubing (7) threaded connection in proper order.

2. A downhole tool for deep sea drilling less permanent well abandonment according to claim 1, wherein the injection port (13) is trumpet-shaped.

3. A downhole tool for deep sea drilling less permanent well abandonment according to claim 1, wherein the diameter of the injection channel between ball seat ii (43) and ball seat i (12) is smaller than the injection channel above ball seat ii (43).

4. The downhole tool for deep sea drilling-free permanent well abandonment according to claim 1, wherein the inner diameter of the ball seat ii (43) is smaller than the inner diameter of the sliding sleeve ii, and the inner diameter of the ball seat i (12) is smaller than the inner diameter of the sliding sleeve i (9).

5. A downhole tool for deep sea drilling machine free permanent well abandonment according to claim 1, wherein the flaring structure (22) is a rubber structure.

6. A method of operation using the downhole tool of any of claims 1-5, comprising the steps of:

s1: the underground operation tool is lowered into the production oil pipe (102) through the continuous oil pipe (7), high-pressure cement paste is pumped into the injection channel through the continuous oil pipe (7), the expansion of the outward expansion structure (22) is realized under the action of pressure, and the anchoring claw teeth (42) are in an anchoring state under the action of the pressure in the pipe;

s2: the cement paste is extruded into the stratum through the bottom injection opening (13) under the action of high pressure; stopping the pump when the length of the extruded cement plug meets the requirement, lifting the working tool for waiting for solidification, injecting liquid into the ground for pressure test after waiting for solidification is finished, applying pressure through an injection head of a continuous oil pipe (7), and sealing the cement plug of the first section after the strength of the top surface of the exploring side is qualified;

s3: the position of a second section of cement plug is lifted on the working tool, a steel ball I (10) is put into the working tool, pumping pressure is increased, a sliding sleeve I (9) breaks through a shearing pin I (33) under the action of the internal pressure of an injection channel, the shearing pin I falls into the position of a ball seat I (12), and at the moment, a communication hole on the side wall of an injection assembly (3) is opened; pumping high-pressure sand blasting liquid into the injection channel, spraying the high-pressure sand blasting liquid from the nozzle (32) to puncture the pipe wall of the production oil pipe (102), forming a punching hole on the pipe wall of the production oil pipe (102), and enabling the outward expanding structure (22) and the anchoring claw teeth (42) to be in a working state under the action of pressure in the process;

s4: pumping cement slurry pre-fluid into the injection channel, isolating the first section cement plug from the second section cement plug through the pre-fluid, injecting the second section cement plug, injecting the cement plug into the inner cavity of the production oil pipe (102), entering the oil sleeve annulus between the production oil pipe (102) and the sleeve (103) from the punching hole, lifting the continuous oil pipe (7) for waiting for solidification after the injection is completed, testing the pressure and probing the top surface of the cement plug after the waiting for solidification is completed, and sealing the second section cement plug after the cement plug is qualified;

s5: lifting the working tool to a third section of cement plug position, putting a steel ball II (101), improving pumping pressure, breaking a shear pin II by a sliding sleeve II under the action of the internal pressure of an injection channel, falling into a ball seat II (43) of an anchoring component I (4), opening a communication hole on the side wall of an inner cylinder (53), pumping high-pressure sand blasting liquid into the injection channel, ejecting the high-pressure sand blasting liquid from a cutting nozzle (55), cutting a pipe column to be cut by means of jet impact force, and forming a certain torque on an outer cylinder (52), wherein the outer cylinder (52) is connected with the inner cylinder (53) by virtue of a bearing, the outer cylinder (52) rotates relative to the inner cylinder (53) to realize cutting of a production oil pipe (102), forming an annular notch on the production oil pipe (102), and enabling an outward expanding structure (22) and an anchoring claw (42) to be in a working state under the action of the pressure in the process; after cutting is completed, the cut upper production oil pipe is lifted out;

s6: pumping cement slurry pre-liquid into the injection channel, isolating the second section cement plug from the third section cement plug through the pre-liquid, injecting the third section cement plug inwards, filling the whole shaft cavity of the target well section by the cement plug at the moment, finishing extrusion injection after the length of the extrusion cement plug meets the requirement, waiting for solidification by an upward lifting operation tool, testing pressure and probing the top surface of the cement plug after the solidification is finished, and finishing sealing of the third section cement plug after the pressure test is qualified;

s7: finally, recovering the wellhead device to finish the whole well abandoning process.