Integrated pipe column for upwards forging and milling casing pipe and using method

Abstract

The invention discloses an integrated pipe column for upwards forging and milling a casing pipe and a using method. The integrated pipe column comprises a tension compensator, a torque isolator, a first chip guide device, a safety connector, a left-handed mud motor, a casing pipe forging and milling device, a second chip guide device and a guide device which are sequentially connected from top to bottom. The use method comprises the following steps: (1) tripping in a tubular column to establish a circulating channel; (2) opening a milling cutter of the casing forging and milling device; (3) forging and milling operation; and (IV) unfreezing operation and the like. The casing forging and milling device achieves forging and milling operation on a casing from bottom to top, is provided with an independent circulating system, can guide metal chippings to the bottom of the well, improves the casing forging and milling efficiency, reduces the operation cost and reduces the maintenance cost of equipment.

Description

Technical Field

[0001] The invention belongs to the field of casing forging and milling or well abandonment operations, and in particular relates to an integrated pipe column for upward forging and milling of casing and a use method thereof. Background Art

[0002] Tapping the potential of old wells is one of the main ways to achieve the goal of reducing costs and increasing efficiency, that is, grinding and milling the casing to open windows and side drilling on the basis of the original wellbore to save wellhead and upper wellbore costs. In addition, many low-yield oil and gas wells also need to be abandoned, and the key to well abandonment is casing forging and milling. At present, domestic casing forging and milling technology all adopts conventional forging and milling technology from top to bottom, and this technology has problems such as insufficient cutting force of the milling cutter due to the accumulation of iron chips not returned in time, and damage to wellhead equipment by iron chips. Summary of the invention

[0003] The present invention is proposed to solve the problems in the prior art that during the forging and milling operation of casing from top to bottom, iron chips are not returned in time and accumulate, resulting in insufficient cutting force of the milling cutter, the iron chips returned to the ground have a high risk of damaging equipment such as blowout preventers, vibrating screens, and mud pumps, and it is difficult to apply drilling pressure in forward forging and milling, drill jumping is likely to occur, and high requirements are placed on equipment such as well repair machines. The purpose is to provide an integrated pipe column for upward forging and milling of casing and a method of use.

[0004] The present invention is achieved through the following technical solutions:

[0005] An integrated pipe string for upward forging and milling of casing comprises a tension compensator, a torque isolator, a No. I chip guide, a safety joint, a left-handed mud motor, a casing forging and milling device, a No. II chip guide and a guide which are sequentially connected from top to bottom.

[0006] In the above technical solution, the tension compensator includes a spline shaft, a center tube and a lower joint connected in sequence; the top end of the spline shaft is connected to the drill pipe; the outside of the spline shaft is sequentially sleeved with a mud retaining sleeve, a spline sleeve, an extension sleeve and a disc spring from top to bottom; the outside of the center tube is sleeved with a lower sleeve.

[0007] In the above technical scheme, a dust ring, a No. 1 BA ring and a guide belt are arranged in sequence between the inner wall of the end of the mud guard sleeve close to the drill pipe and the outer wall of the spline shaft; the end of the spline sleeve close to the drill pipe is sleeved on the outside of the mud guard sleeve, and the two are connected by threads, and a No. 1 compensator sealing ring is arranged between the inner wall of the spline sleeve and the outer wall of the mud guard sleeve; a No. 1 oil filling hole arranged radially is formed on the outer wall of the spline sleeve, and a No. 1 oil plug is arranged in the No. 1 oil filling hole; a semicircular retaining ring is arranged between the extension sleeve and the spline shaft, and the semicircular retaining ring is sleeved on the spline shaft; an outer cylinder is sleeved on the outside of the extension sleeve, one end of the outer cylinder is threadedly connected to the outer wall of the spline sleeve, and the other end is connected to the lower sleeve The outer wall of the cylinder is threadedly connected; a No. Ⅱ compensator sealing ring is arranged between the outer cylinder and the spline sleeve; the center tube is threadedly connected to the end of the spline shaft; the disc spring is placed between the end face of the extension sleeve and the end face of the center tube; the end of the lower sleeve is sleeved on the outside of the lower joint, and the two are threadedly connected; the outer wall of the lower sleeve forms a No. Ⅱ oil filling hole arranged in the radial direction, and a No. Ⅱ oil plug is arranged in the No. Ⅱ oil filling hole; a compensator piston is arranged between the lower sleeve and the center tube, the compensator piston is sleeved on the outside of the center tube, and No. Ⅱ BA rings are arranged on the inside and outside of the compensator piston; a locking nut is arranged between the lower joint and the center tube, and the locking nut is threadedly connected to the outer wall of the center tube.

[0008] In the above technical solution, the safety joint plays a role in releasing the jam; the safety joint includes a safety upper joint and a safety lower joint connected to each other, a safety ball seat is arranged inside the safety upper joint, and the safety ball seat and the safety upper joint are connected by a plurality of safety shear pins evenly distributed along the circumference; a safety steel ball is arranged on the upper joint side of the safety ball seat. A plurality of elastic claws are evenly distributed along the circumference at the lower end of the safety upper joint, and a spline structure is arranged between the safety upper joint and the safety lower joint.

[0009] In the above technical solution, the internal thread of the safety upper joint and the external thread of the safety lower joint are both left-handed.

[0010] In the above technical solution, both the rotor and the stator of the left-handed mud motor are left-handed.

[0011] In the above technical scheme, the chip guide No. I and the chip guide No. II have the same structure, only the lead length is different. The chip guide No. I and the chip guide No. II are both composed of a hollow cylinder and a plurality of guide belts evenly distributed along the cylinder. The guide belts are spirally coiled, and chip guide grooves are formed between the connected guide belts. The helix angle of the chip guide grooves is 23°.

[0012] A method for using an integrated pipe string for upward forging and milling of casing comprises the following steps:

[0013] (I) Lower the pipe string to establish a circulation channel

[0014] Use drill pipe to send the integrated pipe string to the predetermined forging and milling position, start the pump, circulate at a small displacement, and pass through the tension compensator, torque isolator, No. Ⅰ chip guide, safety joint, left-hand mud motor, casing forging and milling device, No. Ⅱ chip guide and guide in sequence, and return to the wellhead through the annulus;

[0015] (II) Open the milling cutter of the casing forging mill

[0016] After the circulation channel is established, gradually increase the displacement until the pump pressure reaches the preset value, maintain the displacement, lift the pipe column, observe the hanging weight, and confirm whether the milling cutter is open;

[0017] (III) Forging and milling operations

[0018] Keep the displacement and hanging weight unchanged. Under the action of throttling pressure difference, the torque isolator automatically opens and anchors on the inner wall of the casing, isolating the reverse torque and returning it to the top drive. The left-hand mud motor drives the casing forging and milling machine to rotate, and the milling cutter forges and mills the casing.

[0019] (IV) Card release operation

[0020] If the integrated pipe string is stuck and cannot be lifted during the forging and milling operation, a steel ball is put into the wellhead and pumped into the safety joint to pressurize it, and the safety joint is disconnected; the pipe string is lifted up to lift the upper pipe string of the safety joint out of the wellhead. The beneficial effects of the present invention are:

[0021] The present invention provides an integrated pipe column and a method for using it for upward forging and milling of casing, which realizes the forging and milling operation of casing from bottom to top, and has an independent circulation system, which can guide metal debris to the bottom of the well, solving the problem of insufficient cutting force of the milling cutter caused by the accumulation of iron chips in the conventional forging and milling operation from top to bottom, thereby improving the efficiency of casing forging and milling and reducing the operation cost. At the same time, the risk of damage to equipment such as blowout preventers, vibrating screens, and mud pumps by iron chips returning to the ground is reduced, and the maintenance cost of the equipment is reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic diagram of a half-section structure of the length of the integrated pipe column of the present invention;

[0023] Figure 2 It is a structural schematic diagram of the tension compensator of the present invention;

[0024] Figure 3 It is a structural schematic diagram of the torque isolator in the present invention;

[0025] Figure 4 is a diagram of the use state of the torque isolator in the present invention;

[0026] Figure 5 It is a schematic diagram of the structure of the support wheel of the torque isolator in the present invention;

[0027] Figure 6 It is a schematic diagram of the structure of the safety joint in the present invention;

[0028] Figure 7 It is a structural schematic diagram of the safety upper joint of the safety joint in the present invention;

[0029] Figure 8 It is a structural schematic diagram of the safety lower joint of the safety joint in the present invention;

[0030] Fig. 9 It is a structural schematic diagram of the casing forging and milling machine in the present invention;

[0031] Fig.10 It is a schematic structural diagram of the milling tool body of the casing forging and milling machine of the present invention;

[0032] Fig.11 It is a schematic diagram of the half-section structure of chip guide No. I and chip guide No. II in the present invention.

[0033] in:

[0034] 1. Tension compensator;

[0035] 11. Spline shaft; 12. Dust seal; 13. No. Ⅰ BA ring; 14. Guide belt;

[0036] 15. Mud retaining sleeve; 16. No. Ⅰ compensator sealing ring; 17. Spline sleeve; 18. Oil plug; 19. No. Ⅱ compensator sealing ring; 110. Outer cylinder; 111. Extension sleeve; 112. Semicircular retaining ring; 113. Disc spring; 114. Center tube; 115. Lower sleeve; 116. No. Ⅱ BA ring; 117. Compensator piston; 118. Lower joint; 119. Lock nut;

[0037] 2. Torque isolator;

[0038] 21. body; 22. isolator pressure block; 23. support wheel mounting block; 24. isolator pin; 25. support wheel; 26. piston; 261. sealing groove; 27. isolator spring; 28. fixing pin;

[0039] 3. Chip guide No. Ⅰ;

[0040] 4. Safety joint;

[0041] 41. Safety upper joint; 42. Safety ball seat; 43. Safety lower joint; 44. Safety shear pin; 45. Safety steel ball; 46. Elastic claw; 47. Safety slot; 48. Spline protrusion; 49. Spline groove;

[0042] 5. Left-handed mud motor;

[0043] 6. Casing forging and milling machine;

[0044] 61. Injection joint; 62. Upper nozzle; 63. Washer; 64. Forging and milling machine spring; 65. Milling tool body; 66. Upper piston mandrel; 67. Floating piston; 68. Lower piston mandrel; 69. Blade stop sleeve; 610. Milling blade; 611. Forging and milling machine pin; 612. Blade fixing block; 613. Forging and milling machine pressure block; 614. No. Ⅰ pin; 615. No. Ⅱ pin; 616. No. Ⅲ pin; 617. Lower nozzle; 618. Communication hole; 619. Spiral groove; 620. Knife groove;

[0045] 7. Chip guide No. Ⅱ;

[0046] 8. Introducer;

[0047] 9. Drill rod;

[0048] For ordinary technicians in this field, other relevant drawings can be obtained based on the above drawings without any creative work. DETAILED DESCRIPTION

[0049] In order to enable those skilled in the art to better understand the technical solution of the present invention, the technical solution of the present invention is further described below with reference to the accompanying drawings and through specific implementation methods.

[0050] like Figure 1 As shown, an integrated pipe string for upward forging and milling of casing comprises a tension compensator 1, a torque isolator 2, a No. I chip guide 3, a safety joint 4, a left-handed mud motor 5, a casing forging and milling device 6, a No. II chip guide 7 and a guide 8 which are sequentially connected from top to bottom;

[0051] The main function of the tension compensator 1 is to compensate for the loss of drilling pressure caused by the upward movement of the pipe string during forging and milling operations.

[0052] like Figure 2 As shown, the tension compensator 1 comprises a spline shaft 11, a center tube 114 and a lower joint 118 connected in sequence;

[0053] The top end of the spline shaft 11 is connected to the drill rod 9, and the buckle type is left-handed, which is used to prevent the casing from being disengaged during forging and milling operations;

[0054] The spline shaft 11 is sleeved with a mudguard sleeve 15, a spline sleeve 17, an extension sleeve 111 and a disc spring 113 in sequence from top to bottom.

[0055] The central tube 114 is sleeved with a lower sleeve 115, and the central tube 114 and the drill pipe end surfaces of the lower sleeve 115 are flush;

[0056] A dust ring 12, a No. 1 BA ring 13 and a guide belt 14 are arranged in sequence between the inner wall of the end of the mud retaining sleeve 15 close to the drill pipe 9 and the outer wall of the spline shaft 11; the dust ring 12 is used to prevent external pollutants from entering the tension compensator 1; the BA ring 13 and the guide belt 14 play a sealing role;

[0057] The end of the spline sleeve 17 close to the drill pipe 9 is sleeved on the outside of the mud guard sleeve 15, and the two are connected by threads. A No. I compensator sealing ring 16 is arranged between the inner wall of the spline sleeve 17 and the outer wall of the mud guard sleeve 15, and the No. I compensator sealing ring 16 plays a sealing role; the outer wall of the spline sleeve 17 forms a No. I oil filling hole arranged radially, and a No. I oil plug 18 is arranged in the No. I oil filling hole. The No. I oil filling hole communicates with the gap between the inner wall of the spline sleeve 17 and the outer wall of the spline shaft 11, which is used to inject hydraulic oil into the tension compensator 1 to increase the wear resistance of internal components;

[0058] A semicircular retaining ring 112 is arranged between the extension sleeve 111 and the spline shaft 11. The semicircular retaining ring 112 is sleeved on the spline shaft 11. The semicircular retaining ring 112 mainly limits the spline sleeve 17. The extension sleeve 111 limits the semicircular retaining ring 112 inside the extension sleeve 111 to prevent it from falling.

[0059] The outer sleeve 110 is sleeved on the outside of the extension sleeve 111, one end of the outer sleeve 110 is threadedly connected to the outer wall of the spline sleeve 17, and the other end is threadedly connected to the outer wall of the lower sleeve 115; a No. II compensator sealing ring 19 is arranged between the outer sleeve 110 and the spline sleeve 17, and the No. II compensator sealing ring 19 plays a sealing role;

[0060] The central tube 114 is threadedly connected to the end of the spline shaft 11;

[0061] The disc spring 113 is placed between the end surface of the extension sleeve 111 and the end surface of the center tube 114;

[0062] The end of the lower sleeve 115 is sleeved on the outside of the lower joint 118, and the two are threadedly connected;

[0063] The outer wall of the lower sleeve 115 is formed with a radially arranged No. II oil filling hole, and a No. II oil plug 120 is arranged in the No. II oil filling hole;

[0064] A compensator piston 117 is disposed between the lower sleeve 115 and the center tube 114. The compensator piston 117 is sleeved outside the center tube 114. No. II BA rings 116 are disposed inside and outside the compensator piston 117.

[0065] A locking nut 119 is provided between the lower joint 118 and the center tube 114. The locking nut 119 is threadedly connected to the outer wall of the center tube 114. The locking nut 119 serves to limit the compensator piston 117.

[0066] When the tension compensator 1 is working, the integrated milling pipe string is lifted up, the spline shaft 11 moves up with the pipe string, and the disc spring 113 is compressed to achieve the purpose of energy storage. During the forging and milling operation, the integrated milling pipe string moves up slowly, and the disc spring 113 is slowly released to compensate for the drilling pressure loss caused by the upward movement of the pipe string during the forging and milling operation.

[0067] The torque isolator 2 can isolate the reverse torque and return it to the wellhead, causing the drill pipe to buckle. At the same time, it can move up and down with the pipe string while isolating the reverse torque during the forging and milling operation. Figures 3 to 5 As shown, the torque isolation device includes a body 21, an isolator pressing block 22, a wheel cavity 23, an isolator pin 24, a support wheel 25, a piston 26, an isolator spring 27 and a fixing pin 28; an open groove is formed on the body 21, and the isolator pressing block 22 and the support wheel mounting block 23 are placed in the open groove. A wheel cavity is formed in the support wheel mounting block 23, and the support wheel 25 is installed in the wheel cavity through the isolator pin 24. After the support wheel 25 is installed, part of the wheel body protrudes from the wheel cavity; the support wheel 25 can rotate on the isolator pin 24, so as to isolate the reverse torque without affecting the axial displacement of the inverted milling pipe column; lug structures are provided at both ends of the support wheel mounting block 23, and two circular hole grooves are provided on the surface of the lug, and the isolator spring 27 is placed therein. Similarly, the isolator pressing block 22 is also provided with a lug structure, and two circular hole grooves corresponding to the lugs on the support wheel mounting block 23 are provided on the lower surface of the lug. The isolator pressing block 22 is pressed on the isolator spring 27, thereby pressing the support wheel mounting block 23 into the open groove on the main body 21, and the isolator pressing block 22 is fixed to the main body 21 by the fixing pin 28. At this time, the isolator spring 27 is in a compressed state, and under the action of the elastic force, the support wheel mounting block 23 is tightly attached to the bottom of the opening groove of the body 21, ensuring that the support wheel 25 will not be propped up during the lowering of the pipe string;

[0068] The bottom of the opening groove of the body 21 is provided with a piston cavity, which is located directly below the support wheel mounting block 23 and is connected to the central cavity of the body 21. The piston 26 is installed in the piston cavity and contacts the bottom of the support wheel mounting block 23. Its main function is to push the piston 26 upward through the throttling pressure difference generated by the central cavity, thereby pushing the support wheel mounting block 23 upward, and finally making the support wheel 25 bite into the inner wall of the casing;

[0069] The wheel surface of the support wheel 25 is conical, and the top is subjected to heat treatment processes such as carburizing, quenching, and tempering to increase the hardness of its outer surface, so as to facilitate biting into the inner wall of the casing. The piston 26 is provided with two sealing grooves 261, and sealing rings are provided in the sealing grooves 261 to play a sealing role;

[0070] During the inverted milling operation, a throttling pressure difference is generated inside the drill string, pushing the piston 26 upward, and then pushing the support wheel mounting block 23 upward, and the support wheel mounting block 23 drives the support wheel 25 to bite into the casing. At this time, the isolator spring 27 is in a further compressed state. When the drill string is displaced axially, since the support wheel 25 and the isolator pin 24 are matched with the sleeve, the support wheel 25 can bite into the casing without affecting the axial displacement of the entire drill string. When the operation is completed, the throttling pressure difference disappears, and under the action of the isolator spring 27, the support wheel mounting block 23 is pressed into the open groove of the body 21, and the piston 26 is pressed back to the initial position, and the torque isolator returns to its initial state.

[0071] The torque isolator 2 in the present invention adopts an integral design, which ensures the structural stability of the tool and meets the tensile and torsional requirements on site; the torque isolator 2 part has been patented, and the patent number is 202410189781.7.

[0072] like Figure 6 , 7 As shown in , 8, the safety joint 4 plays a role in releasing the card; the safety joint 4 includes a safety upper joint 41 and a safety lower joint 43 connected to each other, a safety ball seat 42 is arranged inside the safety upper joint 41, and the safety ball seat 42 is connected to the safety upper joint 41 through a plurality of safety shear pins 44 evenly distributed along the circumference; a safety steel ball 45 is arranged on the upper joint side of the safety ball seat 42;

[0073] A plurality of spline grooves 49 are evenly distributed along the circumference of the connection end of the safety upper joint 41 and the safety lower joint 43, and a plurality of spline protrusions 48 are evenly distributed along the circumference of the connection end of the safety lower joint 43 and the safety upper joint. The spline protrusions 48 are inserted into the spline grooves 49, and the two cooperate to form a spline structure;

[0074] The connection ends of the safety upper joint 41 and the safety lower joint 43 form a plurality of elastic claws 46 evenly distributed along the circumference, and the outer walls of the elastic claws 46 form protrusions;

[0075] The inner wall of the safety lower joint 43 forms a safety slot 47, which cooperates with the protrusion on the outer wall of the elastic claw 46 to connect the safety upper joint 41 with the safety lower joint 43; at the same time, the purpose of torque transmission is achieved through the mutual cooperation of the spline structure;

[0076] The lower end of the safety ball seat 42 supports the elastic claw 46 of the safety upper joint 41 to prevent the safety upper joint 41 from being disengaged from the safety lower joint 43;

[0077] After the safety steel ball 45 is put in, it is pressed, the safety shear pin 44 is cut off, and the safety ball seat 42 moves down, losing the supporting effect on the elastic claw 46 on the safety upper joint 41. Under the action of the pulling force, the safety upper joint 41 is separated from the safety lower joint 43. Thus, the integrated pipe string can be pulled out of the wellhead.

[0078] When the integrated pipe string encounters resistance during the forging and milling of the casing and cannot be lifted up or lowered, a safety steel ball 45 is put in to pressurize the safety joint 4 so that the safety joint 4 can be disconnected and the integrated pipe string can be pulled out.

[0079] The left-handed mud motor 5 provides power to drive tools such as the casing forging and milling machine 6 and the chip guide 3 to operate; the left-handed mud motor 5 consists of a rotor and a stator, and its structure is a conventional motor structure. During the forging and milling operation, the motor needs to rotate in a left direction, so the rotor and stator are designed to rotate in the left direction.

[0080] The casing forging and milling machine 6 realizes the upward forging and milling operation of the casing, and has a total of six sets of milling cutters, with hard alloy teeth welded on the surface. Through reasonable layout, iron filings are prevented from becoming wires.

[0081] like Fig. 9 , 10 As shown, the casing forging and milling machine comprises a housing, a piston telescopic mechanism and a blade wing unfolding mechanism; the piston telescopic mechanism is arranged in the housing;

[0082] The housing comprises a threaded injection joint 61 and a milling tool body 65, and a plurality of upper nozzles 62 are evenly distributed along the circumference of the injection joint 61;

[0083] The injection joint 61 is in the shape of a hollow sleeve, with one end connected to the milling tool body 65 forming an external connection thread, and the other end forming an internal connection thread; a plurality of obliquely arranged through holes are evenly distributed on the wall of the injection joint 61, and the through holes are connected to the central cavity of the injection joint 61, and two to four through holes are arranged and obliquely downward, and the angle α between the axis of the through hole and the axis of the injection joint 61 is 30° to 60°; the nozzle 62 is arranged in the through hole on the wall of the injection joint 61 through a thread, and its function is to spray high-speed fluid downward to flush out the iron filings returning upward in the annulus;

[0084] The milling tool body 65 is in the shape of a hollow stepped sleeve, with multiple knife grooves 620 and multiple spiral grooves 619 evenly distributed radially in the middle of the cylinder wall, and the spiral groove 619 is located at the end of the knife groove 620 away from the injection joint 61; the knife groove 620 is a T-shaped groove, and six are provided; the groove cross-section of the spiral groove 619 is fan-shaped, and the spiral lines are all right-handed, and the spiral groove is used to guide the iron chips milled from the casing to the wellbore annulus at the bottom of the tool;

[0085] The piston extension mechanism is arranged in the milling tool body 65, which includes an upper piston spindle 66 and a lower piston spindle 68 which are threadedly connected, and a floating piston 67 sleeved on the outer side of the lower piston spindle 68, a forging milling spring 64 is sleeved on the outer side of the upper piston spindle 66, and a lower nozzle 617 is arranged at the bottom end of the lower piston spindle 68;

[0086] The upper piston core shaft 66 is in the shape of a hollow sleeve, and its upper end extends into the milling tool body 65; the outer wall of one end of the upper piston core shaft 66 connected to the lower piston core shaft 68 forms a convex ring, which is the lower end limit of the forging and milling machine spring 64; the inner wall of the lower end of the injection joint 61 forms an annular groove, the bottom of the groove is the upper end limit of the forging and milling machine spring 64, and a gasket 63 is arranged between the forging and milling machine spring 64 and the bottom of the groove of the injection joint 61;

[0087] The lower piston core shaft 68 is a hollow cylinder with an open upper end, and a through hole is formed in the middle of the bottom surface thereof, and the lower nozzle 617 is arranged in the through hole through a thread; a truncated cone-shaped convex ring is formed at the lower end of the lower piston core shaft 68, and when the lower piston core shaft 68 moves, the convex ring pushes the grinding and milling blade 610 to realize the expansion of the grinding and milling blade 610;

[0088] The upper piston core shaft 66 and the lower piston core shaft 68 are fixed by a No. Ⅰ pin 614;

[0089] The floating piston 67 is annular, and sealing grooves are provided on the inner and outer walls, and sealing rings are provided in the sealing grooves, that is, sealing rings are provided between the inner wall of the floating piston 67 and the outer wall of the lower piston core shaft 68, and between the outer wall of the floating piston 67 and the inner wall of the milling tool body 65; the upper end surface of the floating piston 67 and the lower end surface of the upper piston core shaft 66 form a lower annular cavity, and the lower annular cavity is connected with the central cavity of the lower piston core shaft 68 through a connecting hole 618 provided on the lower piston core shaft 68. When pressure is generated in the flow channel, the liquid pressure enters the lower annular cavity through the connecting hole, acts on the lower end surface of the upper piston core shaft 66, and interacts with the elastic force of the forging milling machine spring 64 acting on the upper end surface of the upper piston core shaft 66. Under the action of the two forces, the upper piston core shaft 66 and the lower piston core shaft 68 will appear in different position states;

[0090] The forging and milling machine spring 64 is a compression spring. When there is no flow or a small flow in the tool center channel, the pressure of the lower cavity formed by the upper piston core shaft 66 and the floating piston 67 is small. The upper piston core shaft 66 and the lower piston core shaft 68 are located at the lowest end of the stroke. The convex ring of the lower piston core shaft 68 presses against the tail end of the handle of the grinding and milling blade 610. At this time, the grinding and milling blade 610 is in a retracted state; when the flow through the tool center channel increases, the pressure of the lower annular cavity formed by the upper piston core shaft 66 and the floating piston 67 increases. When the liquid pressure in the cavity is greater than the spring force, the upper piston core shaft 66 and the lower piston core shaft 68 will move upward with the forging and milling machine spring 64, pushing the wedge-shaped edge on the back of the grinding and milling blade 610 until the grinding and milling blade 610 is fully unfolded;

[0091] The blade wing deployment mechanism includes a blade stop sleeve 69 sleeved on the outside of the milling tool body 65 and a milling blade 610 arranged in a knife groove 620 of the milling tool body 65, the tail of the milling blade 610 is hinged to the milling tool body 65 through a forging pin 611, and a blade fixing block 612 is arranged between the tail of the milling blade 610 and the milling tool body 65, a forging pressing block 613 is arranged below the blade fixing block 612, and the forging pressing block 613 is fixed in the T-shaped knife groove 620 arranged in the middle of the milling tool body 65 through a No. III pin 616;

[0092] The blade stop sleeve 69 is in the shape of a sleeve, and its inner wall forms a thread, which is threadedly connected to the outer wall of the grinding and milling tool body 65, and the two are fixed by a No. II pin 615; after the blade stop sleeve 69 is connected to the grinding and milling tool body 65, the blade stop sleeve 69 will cover a part of the T-shaped knife groove 620 provided on the grinding and milling tool body 65 and a part of the grinding and milling blade 610 installed in the T-shaped knife groove 620, that is, the stop block provided at the front end of the cutting head of the grinding and milling blade 610. When the grinding and milling blade 610 is expanded to a certain extent, the stop block provided at the front end of the cutting head of the grinding and milling blade 610 will be blocked by the blade stop sleeve 69 to prevent the grinding and milling blade 610 from being over-expanded, thereby ensuring that the sleeve inverted grinding and milling tool maintains the best working condition.

[0093] After the tool is lowered to the working position, the flow rate is gradually increased. At this time, the pressure in the lower cavity formed by the upper piston mandrel and the floating piston increases. Under the action of the liquid in the cavity, the upper and lower piston mandrels will shrink the spring and move upward, pushing the milling blade to unfold. When the milling blade is fully unfolded, the drill string begins to rotate to cut and mill the casing. Part 6 of the casing forging and milling device in this application has been patented, with patent number 2024103986251.

[0094] The chip guide No. Ⅰ 3 and chip guide No. Ⅱ 7 can guide the iron chips produced by forging and milling to the bottom of the well;

[0095] like Fig.11 As shown, the chip guide No. 1 3 and the chip guide No. 2 7 have the same structure, only the lead length is different, and the chip guide No. 1 3 and the chip guide No. 2 7 are both composed of a hollow cylinder and a plurality of guide belts evenly distributed along the cylinder, and the guide belts are spirally wound to form chip guide grooves between the connected guide belts, and the helix angle of the chip guide grooves is 23°.

[0096] In this embodiment, the guide belts of chip guide No. Ⅰ 3 and chip guide No. Ⅱ 7 both adopt six-wire right-hand rotation.

[0097] Example 2

[0098] A method for using an integrated pipe string for reverse forging and milling of casing comprises the following steps:

[0099] (I) Lower the pipe string to establish a circulation channel

[0100] Use the drill pipe to send the integrated pipe string to the predetermined forging and milling position, start the pump, circulate at a small displacement, and pass through the tension compensator 1, torque isolator 2, No. Ⅰ chip guide 3, safety joint 4, left-hand mud motor 5, casing forging and milling device 6, No. Ⅱ chip guide 7 and guide 8 in sequence, and return to the wellhead through the annulus;

[0101] (II) Open the milling cutter of the casing forging mill

[0102] After the circulation channel is established, gradually increase the displacement until the pump pressure reaches the preset value, maintain the displacement, lift the pipe column, observe the hanging weight, and confirm whether the milling cutter is open;

[0103] (III) Forging and milling operations

[0104] Keeping the displacement and hanging weight unchanged, under the action of throttling pressure difference, the torque isolator 2 automatically opens and anchors on the inner wall of the casing, isolating the reverse torque and returning it to the top drive, and the left-handed mud motor 5 drives the casing forging and milling device 6 to rotate, and the milling cutter forges and mills the casing;

[0105] (IV) Card release operation

[0106] If the integrated pipe string is stuck and cannot be lifted during the forging and milling operation, a steel ball is put into the wellhead and pumped into the safety joint 4 to pressurize the safety joint, and the safety joint is disconnected; the pipe string is lifted up, and the pipe string above the safety joint 4 can be lifted out of the wellhead.

[0107] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying 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 limiting the present invention. In addition, the terms "first", "second", and the like are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, features defined as "first", "second", and the like may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0108] In the description of the present invention, it should be noted that, 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 it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood by specific circumstances.

[0109] The applicant declares that the above is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention are within the protection scope and disclosure scope of the present invention.

Claims

1. An integrated pipe string for upward forging and milling of casing, characterized in that: The invention comprises a tension compensator (1), a torque isolator (2), a No. I chip guide (3), a safety joint (4), a left-handed mud motor (5), a casing forging and milling device (6), a No. II chip guide (7) and a guide (8) which are connected in sequence from top to bottom.

2. The integrated pipe string for upward forging and milling of casing according to claim 1, characterized in that: The tension compensator (1) comprises a spline shaft (11), a center tube (114) and a lower joint (118) which are connected in sequence; the top end of the spline shaft (11) is connected to a drill pipe (9); the outside of the spline shaft (11) is sleeved with a mud retaining sleeve (15), a spline sleeve (17), an extension sleeve (111) and a disc spring (113) in sequence from top to bottom; and the outside of the center tube (114) is sleeved with a lower sleeve (115).

3. The integrated pipe string for upward forging and milling of casing according to claim 2, characterized in that: A dust ring (12), a No. 1 BA ring (13) and a guide belt (14) are arranged in sequence between the inner wall of the end of the mud guard sleeve (15) close to the drill rod (9) and the outer wall of the spline shaft (11); the end of the spline sleeve (17) close to the drill rod (9) is sleeved on the outside of the mud guard sleeve (15), and the two are connected by threads; a No. 1 compensator sealing ring (16) is arranged between the inner wall of the spline sleeve (17) and the outer wall of the mud guard sleeve (15); the outer wall of the spline sleeve (17) A radially arranged No. Ⅰ oil filling hole is formed on the wall, and a No. Ⅰ oil plug (18) is arranged in the No. Ⅰ oil filling hole; a semicircular retaining ring (112) is arranged between the extension sleeve (111) and the spline shaft (11), and the semicircular retaining ring (112) is sleeved on the spline shaft (11); an outer sleeve (110) is sleeved on the outside of the extension sleeve (111), and one end of the outer sleeve (110) is threadedly connected to the outer wall of the spline sleeve (17), and the other end is threadedly connected to the outer wall of the lower sleeve (115); the outer sleeve (110) A No. II compensator seal ring (19) is arranged between the extension sleeve (10) and the spline sleeve (17); the center tube (114) is threadedly connected to the end of the spline shaft (11); the disc spring (113) is placed between the end surface of the extension sleeve (111) and the end surface of the center tube (114); the end of the lower sleeve (115) is sleeved on the outside of the lower joint (118), and the two are threadedly connected; the outer wall of the lower sleeve (115) is formed with No. II oil filling holes arranged radially, and the No. II oil filling holes A No. II oil plug (120) is arranged inside; a compensator piston (117) is arranged between the lower sleeve (115) and the center tube (114), the compensator piston (117) is sleeved on the outside of the center tube (114), and No. II BA rings (116) are arranged on the inside and outside of the compensator piston (117); a locking nut (119) is arranged between the lower joint (118) and the center tube (114), and the locking nut (119) is threadedly connected to the outer wall of the center tube (114).

4. The integrated pipe string for upward forging and milling of casing according to claim 1, characterized in that: The safety joint (4) plays a role in releasing the jam; the safety joint (4) comprises a safety upper joint (41) and a safety lower joint (43) which are connected to each other; a safety ball seat (42) is arranged inside the safety upper joint (41), and the safety ball seat (42) is connected to the safety upper joint (41) through a plurality of safety shear pins (44) evenly distributed along the circumference; a safety steel ball (45) is arranged on the upper joint side of the safety ball seat (42).

5. The integrated pipe string for upward forging and milling of casing according to claim 4, characterized in that: A plurality of elastic claws (46) are evenly distributed along the circumference of the lower end of the safety upper joint (41), and a spline structure is arranged between the safety upper joint (41) and the safety lower joint (43).

6. The integrated pipe string for upward forging and milling of casing according to claim 1, characterized in that: The internal thread of the safety upper joint (41) and the external thread of the safety lower joint (43) are both left-handed.

7. The integrated pipe string for upward forging and milling of casing according to claim 1, characterized in that: The rotor and stator of the left-handed mud motor (5) are both left-handed.

8. The integrated pipe string for upward forging and milling of casing according to claim 1, characterized in that: The chip guide No. Ⅰ (3) and the chip guide No. Ⅱ (7) have the same structure, and only the lead length is different.

9. The integrated pipe string for upward forging and milling of casing according to claim 8, characterized in that: The chip guide No. Ⅰ (3) and the chip guide No. Ⅱ (7) are both composed of a hollow cylinder and a plurality of guide belts evenly distributed along the cylinder. The guide belts are spirally wound, and chip guide grooves are formed between the connected guide belts. The spiral rise angle of the chip guide grooves is 23°.

10. A method for using the integrated pipe string for upward forging and milling of casing according to claim 1, characterized in that: The following steps are involved: (I) Lower the pipe string to establish a circulation channel Use drill pipe to send the integrated pipe string to the predetermined forging and milling position, start the pump, circulate at a small displacement, and pass through the tension compensator, torque isolator, No. Ⅰ chip guide, safety joint, left-hand mud motor, casing forging and milling device, No. Ⅱ chip guide and guide in sequence, and return to the wellhead through the annulus; (II) Open the milling cutter of the casing forging mill After the circulation channel is established, gradually increase the displacement until the pump pressure reaches the preset value, maintain the displacement, lift the pipe column, observe the hanging weight, and confirm whether the milling cutter is open; (III) Forging and milling operations Keep the displacement and hanging weight unchanged. Under the action of throttling pressure difference, the torque isolator automatically opens and anchors on the inner wall of the casing, isolating the reverse torque and returning it to the top drive. The left-hand mud motor drives the casing forging and milling machine to rotate, and the milling cutter forges and mills the casing. (IV) Card release operation If the integrated pipe string is stuck and cannot be lifted during the forging and milling operation, a steel ball is put into the wellhead and pumped into the safety joint to pressurize it, and the safety joint is disconnected; the pipe string is lifted up and the pipe string above the safety joint is lifted out of the wellhead.

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