Mechanical hydraulic type continuous plugging drilling special tool and method

Abstract

The invention relates to a mechanical hydraulic type continuous leaking stoppage drilling special tool and method.The tool comprises an upper outer pipe, a lower outer pipe, a throttling induction rod, a piston sleeve and a drill bit, an upper limiting step and a lower limiting step are arranged on the inner wall of the lower portion of the upper outer pipe, and a plurality of cutter blocks capable of being opened outwards are arranged on the side wall of the lower portion of the lower outer pipe in the circumferential direction at intervals; a plurality of push blocks are arranged on the outer wall of the piston sleeve in the circumferential direction at intervals. The throttling sensing rod can move downwards to be inserted into the piston sleeve to reduce the equivalent diameter of the piston sleeve when the upper end of the lower outer pipe abuts against the upper limiting step, so that liquid injected into the piston sleeve is throttled and pushes the piston sleeve to move downwards to a preset position, and the cutter block is opened outwards. According to the tool and the method, an existing polished drill rod can be replaced for cement injection for leaking stoppage, a roller bit can also be replaced for cement plug drilling, continuous multiple cement leaking stoppage operation without pulling out of a hole is achieved, meanwhile, after plug drilling is completed, the normal drilling capacity is achieved, the number of times of pulling out of the hole is reduced, and the leaking stoppage operation period is greatly shortened.

Description

Technical Field

[0001] The invention relates to the field of oil drilling, and in particular to a mechanical hydraulic type continuous leak plugging drilling special tool and method. Background Art

[0002] During drilling operations, well leakage seriously restricts the drilling speed. Various complex situations are directly related to well leakage and cause huge economic losses. The treatment of well leakage is related to the exploration and development process, which has always been a special concern of the petroleum engineering community. Due to the complex causes of leakage and many restrictive factors, it has become a technical problem faced by drilling and completion projects. Cement plugging is the main plugging method when the well leakage is serious. Due to the complex downhole conditions, it cannot be guaranteed to be successful in one time, and multiple and repeated plugging may be required in the same leakage layer. In order to achieve the requirements of large-volume rapid cement slurry injection and avoid safety accidents caused by the tool being cemented at the bottom of the well, at present, conventional plugging is to plug the leak with cement through the bare drill pipe, then replace the roller drill bit to drill the cement plug, and then check whether the plugging is successful. If not, repeat the above operation procedures until the plugging is successful. After the plugging is successful, it is necessary to pull out the drill and replace the drill bit assembly to continue drilling. However, although this method of plugging leaks has a good plugging effect, it may require multiple and repeated plugging in the same leaking layer, and the drilling must be frequently tripped and lowered, which complicates the overall process. It not only increases the risk of downhole operations, but also seriously delays the drilling cycle, which is particularly evident in deep wells and ultra-deep wells.

[0003] Therefore, the inventor, relying on his many years of experience and practice in related industries, proposes a mechanical hydraulic continuous plugging drilling special tool and method to overcome the defects of the prior art. Summary of the invention

[0004] The purpose of the present invention is to provide a mechanical hydraulic type continuous plugging drilling special tool and method, which can replace the existing bare drill rod cement injection plugging, and replace the roller drill bit to drill cement plugs, to achieve continuous multiple cement plugging operations without drilling, and at the same time, it still has normal drilling ability after the drilling and plugging are completed, reducing the number of drilling and drilling, and greatly shortening the plugging operation cycle.

[0005] The above-mentioned purpose of the present invention can be achieved by adopting the following technical solutions:

[0006] The present invention provides a mechanical hydraulic type continuous leak plugging drilling special tool, comprising:

[0007] The upper outer tube is arranged vertically, and the inner wall of the lower part thereof is provided with an upper limit step and a lower limit step;

[0008] The upper end of the vertically arranged lower outer tube can move up and down inside the upper outer tube and between the upper limit step and the lower limit step, and can be suspended on the lower limit step under the action of gravity; a plurality of knife blocks that can be opened outwards are arranged at intervals in the circumferential direction of the inner side wall of the lower part;

[0009] A throttling sensing rod, the upper end of which is connected to the upper outer tube and the lower end of which can extend into the lower outer tube;

[0010] The piston sleeve is movable up and down and is arranged in the lower outer tube and is located below the throttling sensing rod. A plurality of push blocks are arranged at intervals in the circumferential direction on the outer wall of the piston sleeve.

[0011] a drill bit connected to the bottom end of the lower outer tube;

[0012] Among them, the throttling sensing rod can move downward and be inserted into the piston sleeve to reduce the equivalent diameter of the piston sleeve when the upper end of the lower outer tube abuts against the upper limit step, so as to cause throttling of the liquid injected into the piston sleeve and push the piston sleeve to move downward to a preset position, and the push block pushes the corresponding knife block outward, and the knife block opens outward; the piston sleeve can move upward and reset after the liquid stops being injected, and retract the knife block inward to the side wall of the lower outer tube.

[0013] In a preferred embodiment of the present invention, an upper stop is provided on the outer wall of the piston sleeve, a lower stop is provided on the inner wall of the lower outer tube, and a piston return spring is provided on the outer sleeve of the piston sleeve, with both ends of the piston return spring respectively abutting between the upper stop and the lower stop.

[0014] In a preferred embodiment of the present invention, a sliding groove is provided on the inner side of the blade block, and the sliding groove includes an inclined groove and a flat groove connected up and down, the bottom groove wall of the inclined groove is an inner inclined surface, and the groove wall of the flat groove is a plane; the lower outer wall of the push block is an outer inclined surface, and its upper outer wall is a vertical plane, the shape of the inclined groove matches the shape of the push block, and when the piston sleeve moves downward to a preset position, the push block can be inserted in the flat groove and the vertical plane is in contact with the groove wall of the flat groove.

[0015] In a preferred embodiment of the present invention, a plurality of mounting openings are circumferentially provided on the outer wall of the lower outer tube, and the upper end of each blade block is connected to the lower outer tube via a rotating shaft, and the axial direction of the rotating shaft is perpendicular to the axial direction of the lower outer tube; an inner bevel is provided on the inner wall of the lower outer tube and adjacent to the lower position of the mounting opening, and an outer bevel is provided on the lower end surface of the blade block, and the outer bevel can abut against the inner bevel after the blade block is opened outward.

[0016] In a preferred embodiment of the present invention, a locking push rod that can elastically move up and down and a locking push rod that can elastically move radially are provided in the side wall of the lower outer tube, the lower end of the locking push rod has an upper inclined surface, the locking push rod is located below the locking push rod and has a lower inclined surface that can cooperate with the upper inclined surface, and the upper inclined surface can abut against the lower inclined surface; a locking limit hole is provided on the outer wall of the piston sleeve, and when the upper end of the lower outer tube abuts against the upper limit step, the lower end surface of the upper outer tube can push the locking push rod to move downward, so that the locking push rod is inserted into the locking limit hole when the piston sleeve moves down to a preset position.

[0017] In a preferred embodiment of the present invention, an upper outer wall of the lower outer tube is provided with an upper limit portion and a lower limit portion, the lower end of the upper outer tube can move between the upper limit portion and the lower limit portion, the upper end of the locking push rod can extend upwardly out of the lower limit portion, and the lower end face of the upper outer tube moves downward and abuts against the lower limit portion to push the locking push rod to move downward; an axial mounting hole and a radial mounting hole are provided in the side wall of the lower outer tube, the upper end of the axial mounting hole penetrates the lower limit portion upward, the radial mounting hole is connected with the lower end of the axial mounting hole and radially penetrates the inner wall of the outer tube; a stepped hole with an increased aperture is formed at the first end of the axial mounting hole, a plug is installed in the end of the stepped hole, and the upper end of the locking push rod can move up and down through the plug The locking push rod has a first annular flange on its upper outer wall, and the first flange is located below the plug. A locking return spring is provided on the outer sleeve of the locking push rod, and two ends of the locking return spring respectively abut against the first flange and the bottom hole shoulder of the stepped hole; a mounting sleeve is provided in the radial mounting hole, and the locking push rod includes a push column and a locking pin arranged in the mounting sleeve, and a lower inclined surface is formed on the push column, and the lower end of the locking push rod can extend into the mounting sleeve and abut against the lower inclined surface; an annular second flange is provided on the upper outer wall of the push column, and a first spring is sandwiched between the second flange and the step in the mounting sleeve, and a second spring is provided between the push column and the locking pin, and the locking pin can extend radially inward and be inserted in the locking limit hole.

[0018] In a preferred embodiment of the present invention, a throttling head is connected to the lower end of the throttling sensing rod, the diameter of the throttling head is larger than the diameter of the throttling sensing rod, and the throttling head can be moved into the piston sleeve.

[0019] In a preferred embodiment of the present invention, a convex ring with a reduced inner diameter is protruded inwardly on the inner wall of the upper end of the piston sleeve; the throttle head can be located in the piston sleeve below the convex ring when the upper end of the lower outer tube abuts against the upper limit step, and can be located in the convex ring when the piston sleeve moves downward to a preset position.

[0020] In a preferred embodiment of the present invention, the upper end of the piston sleeve is connected to a connecting sleeve, and a limiting block is connected to the upper end of the connecting sleeve. A center hole and multiple flow holes are opened on the limiting block. The diameter of the throttling head is larger than the aperture of the center hole. The throttling sensing rod can move through the center hole, and the throttling head is located below the limiting block.

[0021] In a preferred embodiment of the present invention, a plurality of nozzle holes are provided in the lower end of the drill bit, the nozzle holes can communicate with the inner cavity of the piston sleeve and the outer wall of the lower end of the drill bit, and the equivalent diameter of the nozzle holes is greater than or equal to 30 mm.

[0022] In a preferred embodiment of the present invention, the upper outer tube includes an upper joint and an outer movable sleeve connected up and down, and the lower outer tube includes an inner movable sleeve, an outer cylinder and a lower joint connected in sequence from top to bottom, the lower end outer wall of the upper joint is threadedly connected to the upper end inner wall of the outer movable sleeve, the lower end surface of the upper joint constitutes an upper limit step, and the lower limit step is formed on the lower end inner wall of the outer movable sleeve; the upper end outer wall of the inner movable sleeve forms a limiting ring, and the limiting ring can rest on the upper limit step or on the lower limit step; the upper end of the throttling sensing rod is connected to the upper joint, and the lower part thereof is penetrated into the inner movable sleeve; the knife block is installed on the outer cylinder, the piston sleeve is arranged in the outer cylinder, and the bottom end of the lower joint is connected to the drill bit.

[0023] The present invention also provides a mechanical hydraulic continuous leak plugging drilling method, which comprises:

[0024] Connect the drill pipe and the above-mentioned mechanical hydraulic continuous leak plugging drilling tool to form a drilling tool assembly, and lower the mechanical hydraulic continuous leak plugging drilling tool to the leak plugging target layer;

[0025] Start grouting construction. After the cement slurry is injected, start the pump to inject drilling fluid to replace the cement slurry in the drill bit assembly. After the cement slurry replacement operation is completed, pull the drill to a safe position;

[0026] After the cement slurry is solidified, the mechanical hydraulic continuous plugging drilling tool is made to touch the bottom of the well and continue to be pressurized. Under the action of drilling pressure, the lower end of the throttling sensing rod enters the piston sleeve to reduce the equivalent diameter of the piston sleeve. The pump is turned on to the designed displacement. The hydraulic thrust generated between the piston sleeve and the lower end of the throttling sensing rod pushes the piston sleeve downward, and the push block pushes the cutter block outward to start the drilling and plugging construction.

[0027] After the plugging is completed, the drill is pulled out from the bottom of the well, drilling fluid is injected, the well is sealed and the pressure is held down to check whether the plugging is successful;

[0028] If the plugging is unsuccessful, repeat the grouting and drilling until the plugging is successful;

[0029] Carry out drilling operations.

[0030] As described above, the tool and method of the present invention, during the grouting process, the tool does not touch the bottom of the well, the lower outer tube is suspended at the lower end of the upper outer tube under the action of gravity, the throttling sensing rod does not enter the piston sleeve, and the interior of the tool has a larger equivalent diameter to ensure large-displacement grouting; during the plugging process, the tool touches the bottom of the well, and under the action of drilling pressure, the lower outer tube moves upward relative to the upper outer tube, the throttling sensing rod moves into the piston sleeve, a throttling effect is generated in the piston sleeve, and the throttling force is used to push the piston sleeve downward to push the knife block outward to open; the knife block is pushed out in the form of "mechanical + hydraulic", and the opening of the knife block is controlled by the displacement The displacement is controlled, and the cutter block will not be triggered by mistake below the critical displacement. When the cutter block needs to be extended, it only needs to increase the displacement above the critical displacement, so as to realize the switching between the grouting condition and the drilling condition. The operability is better, and the cutter block will not be opened prematurely by mistake during the construction process, and the construction is safer. It realizes multiple consecutive cement plugging and drilling plugging operations without starting the drill, which can greatly simplify the plugging-drilling plugging operation process. At the same time, after the cement drilling plugging is completed, it can continue to drill into the new formation with normal drilling ability, further reducing the number of drilling and pulling out, which not only greatly shortens the plugging operation cycle, but also improves the drilling operation efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The following drawings are only intended to illustrate and explain the present invention, and are not intended to limit the scope of the present invention.

[0032] in:

[0033] Figure 1 : A schematic diagram of the mechanical hydraulic continuous leak plugging drilling special tool provided by the present invention in a grouting condition.

[0034] Figure 2 : A schematic diagram of the mechanical hydraulic continuous leak plugging drilling tool provided by the present invention after the throttling head extends into the piston sleeve.

[0035] Figure 3 : A schematic diagram of the mechanical hydraulic continuous plugging drilling tool provided by the present invention in the drilling and plugging working condition.

[0036] Figure 4 : A schematic diagram of the upper joint provided by the present invention.

[0037] Figure 5 : A schematic diagram of the piston sleeve and the connecting sleeve provided by the present invention.

[0038] Figure 6 : A schematic diagram of a knife block provided by the present invention.

[0039] Figure 7 : An enlarged view of the locking mechanism provided by the present invention.

[0040] Figure 8: A schematic diagram of the cooperation between the mounting sleeve, the top column and the locking pin in the locking mechanism provided by the present invention.

[0041] Fig. 9 : A three-dimensional diagram of the cooperation between the mounting sleeve, the top column and the locking pin in the locking mechanism provided by the present invention.

[0042] Fig.10 : A schematic diagram of the mechanical hydraulic type continuous leak plugging drilling special tool provided by the present invention, in which the throttling head is against the limit block during the forced recovery process.

[0043] Fig.11 : Schematic diagram of the drill bit provided by the present invention Figure 1 .

[0044] Fig.12 : Schematic diagram of the drill bit provided by the present invention Figure 2 .

[0045] Description of Figure Numbers:

[0046] 1. Upper outer tube; 11. Upper joint; 111. Upper limit step; 112. Mounting block; 1121. Liquid hole; 113. Locking nut; 12. Outer movable sleeve; 121. Lower limit step; 122. Upper limit part;

[0047] 2. Lower outer tube; 21. Inner movable sleeve; 22. Outer tube; 221. Lower limit part; 222. Lower stop part; 223. Mounting port; 224. Knife holder; 2241. Rotating shaft; 225. Inner bevel; 226. Axial mounting hole; 23. Lower joint; 231. Stop ring;

[0048] 3. Throttle sensing rod; 31. Throttle head;

[0049] 4. Piston sleeve; 41. Push block; 411. Outer inclined surface; 412. Vertical plane; 42. Locking limit hole; 43. Convex ring; 44. Upper stopper; 45. Piston return spring;

[0050] 5. Connecting sleeve; 51. Limiting block; 511. Flow hole;

[0051] 6. Knife block; 61. Slide groove; 611. Inclined groove; 6111. Inner inclined surface; 612. Flat groove; 613. External inclined surface;

[0052] 7. Locking mechanism; 71. Locking push rod; 711. First flange; 712. Locking return spring; 72. Plug; 73. Mounting sleeve; 731. First stepped hole; 732. Second stepped hole; 733. Opening hole; 74. Top column; 741. Second flange; 75. First spring; 76. Second spring; 77. Locking pin; 78. Block;

[0053] 8. Drill bit; 81. Threaded pipe section; 82. Connecting pipe section; 83. End section; 831. Nozzle hole; 84. Blade; 85. Chip groove; 86. Front row of teeth; 87. Rear row of teeth;

[0054] 9. Bottom of the well. DETAILED DESCRIPTION

[0055] In order to have a clearer understanding of the technical features, purposes and effects of the present invention, specific embodiments of the present invention are now described with reference to the accompanying drawings.

[0056] like Figures 1 to 12 As shown, the present application provides a mechanical hydraulic type continuous plugging and drilling special tool, comprising:

[0057] The upper outer tube 1 is vertically arranged, and the inner wall of the lower part thereof is provided with an upper limit step 111 and a lower limit step 121;

[0058] The upper end of the vertically arranged lower outer tube 2 can move up and down inside the upper outer tube 1 and between the upper limit step 111 and the lower limit step 121, and can be suspended on the lower limit step 121 under the action of gravity; a plurality of knife blocks 6 that can be opened outwards are arranged at intervals in the circumferential direction of the inner side wall of the lower part;

[0059] The throttling sensing rod 3 has an upper end connected to the upper outer tube 1 and a lower end capable of extending into the lower outer tube 2;

[0060] The piston sleeve 4 is movable up and down and is disposed in the lower outer tube 2 and is located below the throttling sensing rod 3. A plurality of push blocks 41 are provided at intervals along the circumference of the outer wall of the piston sleeve 4.

[0061] a drill bit 8 connected to the bottom end of the lower outer tube 2;

[0062] Among them, the throttling sensing rod 3 can move downward and be inserted into the piston sleeve 4 to reduce the equivalent diameter of the piston sleeve 4 when the upper end of the lower outer tube 2 is against the upper limit step 111, so as to cause the liquid injected into the piston sleeve 4 to throttle and push the piston sleeve 4 to move downward to a preset position, and the push block 41 pushes the corresponding knife block 6 outward, and the knife block 6 opens outward; the piston sleeve 4 can move upward and reset after the liquid stops being injected, and the knife block 6 is retracted inward to the side wall of the lower outer tube 2.

[0063] The above-mentioned blade blocks 6 are all located in the side wall of the lower outer tube 2 in the initial state, and the number of push blocks 41 is the same as the number of blade blocks 6. For example, in this embodiment, the number of push blocks 41 and blade blocks 6 are three and are evenly spaced in the circumferential direction. The drill bit 8 has a nozzle hole 831, and the upper port of the upper outer tube 1 is connected with the inner cavity of the piston sleeve 4 and the nozzle hole 831 on the drill bit 8 to form a liquid flow channel for liquid (cement slurry or drilling fluid) to flow through.

[0064] The upper outer tube 1 and the lower outer tube 2 are mutually sleeved and can move relative to each other. The throttling sensing rod 3 and the piston sleeve 4 connected to the two parts can produce relative movement. When in use, the relative position of the throttling sensing rod 3 and the piston sleeve 4 can be controlled by coordinating simple drilling operations to produce an active throttling effect, thereby completing the switching between the grouting working condition and the drilling plug working condition. Specifically, before the tool contacts the bottom of the well 9, the tool always remains in the grouting working condition (such as Figure 1 The principle is that when the tool does not contact the bottom of the well 9, due to the deadweight of the tool, the lower outer tube 2 and the piston sleeve 4 and the cutter block 6 inside it will be suspended at the lower part of the upper outer tube 1. At this time, the upper end of the lower outer tube 2 is suspended on the lower limit step 121 of the upper outer tube 1, and a certain distance is maintained between the upper end of the piston sleeve 4 and the lower end of the throttling sensing rod 3, so as to ensure that the inner cavity of the tool has a larger diameter, so as to meet the demand of large displacement and rapid injection of cement slurry, and the cement slurry flows out after passing through the above-mentioned liquid circulation channel; at the same time, during the drilling or circulation process, since the liquid displacement is lower than the critical displacement of the piston sleeve 4 moving downward, the piston sleeve 4 will not move downward, which effectively avoids the situation that the throttling sensing rod 3 enters the piston sleeve 4 and triggers the expansion of the cutter block 6 due to the friction between the tool and the well wall.

[0065] When it is necessary to switch from the grouting condition to the drilling condition, the pump is turned on to inject drilling fluid to replace the cement slurry in the drill tool. After the cement slurry is replaced and the cement slurry is solidified, the tool is made to touch the bottom of the well 9 and continue to be pressurized. Under the action of the drilling pressure, the lower outer tube 2 moves upward relative to the upper outer tube 1 and "squeezes" into the upper outer tube 1, driving the piston sleeve 4 to move upward relative to the upper outer tube 1. The tail of the throttling sensing rod 3 will enter the piston sleeve 4 to reduce the equivalent diameter of the piston sleeve 4 (such as Figure 2 At this time, the pump is turned on to the designed displacement, and active throttling is generated between the piston sleeve 4 and the tail of the throttling sensing rod 3 to form a hydraulic thrust. The throttling force pushes the piston sleeve 4 downward to a preset position, and each push block 41 on the piston sleeve 4 pushes each knife block 6 to open outward, so that the outer diameter of each knife block 6 expands to a full-eye size to form a drilling plug working condition, such as Figure 3 As shown; drilling operations can be performed by driving the entire tool to rotate.

[0066] When the plugging is completed, stop the displacement (stop injecting liquid), lift the tool, and move the upper outer tube 1 upward relative to the lower outer tube 2 so that the upper end of the lower outer tube 2 abuts against the lower limit step 121 and returns to the initial state. The piston sleeve 4 will move up and reset, and the cutter block 6 will also be retracted. At the same time, the well sealing and pressure test is carried out. If the well leakage still exists, the plugging and plugging operations are carried out again until the pressure test meets the requirements. After the plugging is successful, push the cutter block 6 outward to open, and then you can continue drilling normally.

[0067] Therefore, the tool of the present application does not touch the bottom of the well 9 during the grouting process, and the lower outer tube 2 is suspended at the lower end of the upper outer tube 1 under the action of gravity, and the throttling sensing rod 3 does not enter the piston sleeve 4. The interior of the tool has a larger equivalent diameter to ensure large-displacement grouting; during the plug drilling process, the tool touches the bottom of the well 9, and under the action of the drilling pressure, the lower outer tube 2 moves upward relative to the upper outer tube 1, and the throttling sensing rod 3 moves into the piston sleeve 4, and a throttling effect is generated in the piston sleeve 4. The throttling force is used to push the piston sleeve 4 downward to push the knife block 6 to open outward; the knife block 6 is pushed out in the form of "mechanical + hydraulic". The opening is controlled by the displacement. The knife block 6 will not be triggered by mistake below the critical displacement. When the knife block 6 needs to be extended, it only needs to increase the displacement above the critical displacement, so as to realize the switching between the grouting condition and the drilling condition. The operability is better, and the knife block 6 will not be opened prematurely by mistake during the construction process, and the construction is safer. It realizes multiple consecutive cement plugging and drilling operations without drilling, which can greatly simplify the plugging-drilling operation process. At the same time, after the cement drilling and plugging are completed, it can continue to drill into the new formation, have normal drilling ability, further reduce the number of drilling and pulling out, not only greatly shorten the plugging operation cycle, but also improve the drilling operation efficiency.

[0068] In a specific implementation, a mounting block 112 having a center hole and a plurality of liquid holes 1121 is provided in the upper outer tube 1. The upper end of the throttling sensing rod 3 passes through the center hole and is fixed to the mounting block 112. For example, the throttling sensing rod 3 can be fixed to the mounting block 112 by using two locking nuts 113 on the upper and lower end surfaces of the mounting block 112. The liquid holes 1121 can allow liquid (cement slurry or drilling fluid) to flow through. The shape of the liquid holes 1121 can be as follows: Figure 4 The hole shown in the figure is a waist-shaped hole. The specific size and number of the flow holes 511 are determined according to needs to ensure that the tool has a sufficient equivalent diameter.

[0069] In actual applications, a large force is generally required to push the piston sleeve 4. In order to make the throttling force generated when the piston sleeve 4 is throttled larger, the lower end of the throttling sensing rod 3 is connected (for example, threaded) with a throttling head 31. The diameter of the throttling head 31 is larger than the diameter of the throttling sensing rod 3, and the throttling head 31 can move into the piston sleeve 4. In this embodiment, the diameter of the throttling head 31 is close to the inner diameter of the piston sleeve 4. When the lower outer tube 2 moves upward relative to the upper outer tube 1, the throttling head 31 enters the piston sleeve 4, so that the equivalent diameter of the piston sleeve 4 is sharply reduced to generate sufficient throttling force.

[0070] In order to facilitate the resetting of the piston sleeve 4, an upper stopper 44 is provided on the outer wall of the piston sleeve 4, a lower stopper 222 is provided on the inner wall of the lower outer tube 2, and a piston return spring 45 is provided on the outer sleeve of the piston sleeve 4, and the two ends of the piston return spring 45 are respectively pressed between the upper stopper 44 and the lower stopper 222.

[0071] In the grouting condition, during the drilling or circulation process, the displacement is lower than the critical displacement of the piston return spring 45 moving downward, and the thrust generated by the throttling cannot overcome the upward thrust of the piston sleeve 4, so the piston sleeve 4 will not move downward. When switching to the drilling and plugging condition, the throttling effect generated in the piston sleeve 4 pushes the piston sleeve 4 downward to compress the piston return spring 45, so as to use the push block 41 to push out the knife block 6. When the drilling and plugging is completed and the displacement is stopped and the tool is lifted, under the condition of no liquid pressure generated by throttling, the expansion force generated by the piston return spring 45 pushes the piston sleeve 4 upward to reset, and at the same time, the push block 41 of the piston sleeve 4 drives the knife block 6 back to its original position.

[0072] Further, see Figure 5 and Figure 6 A slide groove 61 is provided on the inner side of the blade block 6, and the slide groove 61 includes an inclined groove 611 and a flat groove 612 connected up and down. The bottom groove wall of the inclined groove 611 is an inner inclined surface 6111, and the groove wall of the flat groove 612 is a plane; the lower outer wall of the push block 41 is an outer inclined surface 411, and its upper outer wall is a vertical plane 412. The shape of the inclined groove 611 matches the shape of the push block 41. When the piston sleeve 4 moves downward to the preset position, the push block 41 can be inserted into the flat groove 612 and the vertical plane 412 fits with the groove wall of the flat groove 612.

[0073] The longitudinal section of the inclined groove 611 along the axial direction of the lower outer tube 2 is a right-angled trapezoid, and the longitudinal section of the push block 41 along the axial direction of the lower outer tube 2 is also a right-angled trapezoid. The shapes of the two are matched, and the hypotenuse of the right-angled trapezoid faces downward. In the initial state, the knife block 6 is located in the side wall of the lower outer tube 2, and the push block 41 is inserted in the inclined groove 611 of the knife block 6. The knife block 6 is provided with a slide groove 61, which cooperates with the push block 41 of the piston sleeve 4 to ensure that the knife block 6 slides along the push block 41, and at the same time ensures that the piston sleeve 4 will not rotate arbitrarily inside the tool; the slide groove 61 of the knife block 6 is in the shape of a slope-plane, with the slope as a guide and the plane as a limit, which ensures that the knife block 6 will not be compressed and retracted due to external force after opening, and the structure is more stable.

[0074] Reference Figure 2 and Figure 3 A plurality of mounting openings 223 are circumferentially provided on the outer wall of the lower outer tube 2, and the upper end of each blade block 6 is connected to the lower outer tube 2 via a rotating shaft 2241, and the axial direction of the rotating shaft 2241 is perpendicular to the axial direction of the lower outer tube 2; an inner bevel 225 is provided on the inner wall of the lower outer tube 2 and adjacent to the lower position of the mounting opening 223, and an outer bevel 613 is provided on the lower end surface of the blade block 6, and the outer bevel 613 can abut against the inner bevel 225 after the blade block 6 is opened outward.

[0075] Generally, a knife seat 224 is installed at the upper end of the installation opening 223. The knife seat 224 is connected to the lower outer tube 2 through a fastener, and the upper end of the knife block 6 is connected to the knife seat 224 through a rotating shaft 2241, which makes processing and installation more convenient. A U-shaped groove is provided on the lower end surface of the knife seat 224, so that the knife seat 224 is closely attached to the arc-shaped connecting block at the upper end of the knife block 6 (the arc-shaped connecting block is provided with a mounting hole for installing the rotating shaft 2241). When drilling plugs, the axial force of the knife block 6 can directly act on the knife seat 224, avoiding damage to the rotating shaft 2241 by force, and improving the service life of the knife block 6. The above-mentioned inner bevel 225 limits the position of the knife block 6 to open outward, ensuring that the knife block 6 will not continue to expand after opening to a specified size.

[0076] Furthermore, a locking mechanism 7 is provided inside the lower outer tube 2, and its function is to limit and lock the cutter block 6 when it is extended to a specified wellbore size under the drilling and plugging condition. The details are as follows:

[0077] A locking push rod 71 that can elastically move up and down and a locking push rod that can elastically move radially are provided in the side wall of the lower outer tube 2. The lower end of the locking push rod 71 has an upper inclined surface. The locking push rod is located below the locking push rod 71 and has a lower inclined surface that can cooperate with the upper inclined surface. The upper inclined surface can abut against the lower inclined surface; a locking limit hole 42 is provided on the outer wall of the piston sleeve 4. When the upper end of the lower outer tube 2 abuts against the upper limit step 111, the lower end surface of the upper outer tube 1 can push the locking push rod 71 to move downward, so that the locking push rod is inserted into the locking limit hole 42 when the piston sleeve 4 moves down to a preset position.

[0078] More specifically, the structure and installation of the locking push rod 71 and the locking push rod can be achieved as follows: Figure 1 as well as Figures 7 to 9 The upper outer wall of the lower outer tube 2 is provided with an upper limit portion 122 and a lower limit portion 221. The lower end of the upper outer tube 1 can move between the upper limit portion 122 and the lower limit portion 221. The upper end of the locking push rod 71 can extend upward from the lower limit portion 221. When the lower end surface of the upper outer tube 1 moves downward and abuts against the lower limit portion 221, the locking push rod 71 can be pushed to move downward. An axial mounting hole 226 and a radial mounting hole are opened in the side wall of the lower outer tube 2. The upper end of the axial mounting hole 226 penetrates the lower limit portion 221 upward, and the radial mounting hole is aligned with the axial mounting hole. The lower end of the mounting hole 226 is connected to and radially penetrates the inner wall of the outer tube; the first end of the axial mounting hole 226 is formed with a stepped hole with an increased aperture, and a plug 72 is installed in the end of the stepped hole. The upper end of the locking push rod 71 can move up and down through the plug 72, and the upper outer wall of the locking push rod 71 has an annular first flange 711, and the first flange 711 is located below the plug 72. The locking push rod 71 is outer-circuited with a locking return spring 712, and the two ends of the locking return spring 712 respectively press against the first flange 711 and the bottom hole shoulder of the stepped hole.

[0079] A mounting sleeve 73 is provided in the radial mounting hole, and the locking push rod includes a push column 74 and a locking pin 77 arranged in the mounting sleeve 73. A lower inclined surface is formed on the push column 74, and the lower end of the locking push rod 71 can extend into the mounting sleeve 73 and abut against the lower inclined surface; an annular second flange 741 is provided on the upper outer wall of the push column 74, and a first spring 75 is sandwiched between the second flange 741 and the step in the mounting sleeve 73, and a second spring 76 is provided between the push column 74 and the locking pin 77, and the locking pin 77 can extend radially inward and be inserted in the locking limit hole 42.

[0080] The center of the plug 72 has an opening 733 to facilitate the locking push rod 71 to pass through. The inner hole of the mounting sleeve 73 includes a first step hole 731 and a second step hole 732 that are connected to each other. The diameter of the second step hole 732 is larger than that of the first step hole 731, and the diameter of the first step hole 731 is larger than the diameter of the top column 74. The locking pin 77 and the second spring 76 are located in the first step hole 731, and the top column 74 is located in the second step hole 732 and its lower end extends into the first step hole 731. The two ends of the first spring 75 are respectively pressed against the second flange 741 and the shoulder of the second step hole 732 (i.e., the step in the mounting sleeve 73). The two ends of the second spring 76 are generally fixed between the top column 74 and the locking pin 77. In order to facilitate installation, the radial installation hole also radially penetrates the outer wall of the lower outer tube 2. After installing all the components, a block 78 is installed (threaded) in the radial installation hole near the outer wall of the lower outer tube 2 to isolate the external liquid. A limiting step is provided on the inner wall of the inner side of the radial installation hole, and the middle outer wall of the installation sleeve 73 has a corresponding step and abuts against the limiting step. The inner end face of the block 78 is pressed on the outer end face of the installation sleeve 73 to position the installation sleeve 73.

[0081] Of course, in order to play a better guiding role, the inner end portion of the first stepped hole 731 can also form a stepped hole with a reduced aperture, and the locking pin 77 is located in the stepped hole.

[0082] During use, when the lower end surface of the upper outer tube 1 moves downward and abuts against the lower limit portion 221, the lower end surface of the upper outer tube 1 pushes the locking push rod 71 to move downward, and pushes the top column 74 to move radially inward through the action of the upper and lower inclined surfaces, and pushes the locking pin 77 to move inward; due to the existence of the second spring 76, before the piston sleeve 4 moves down to the preset position, that is, before the locking limit hole 42 is in place, the end of the locking pin 77 will not push the piston sleeve 4. When the locking limit hole 42 moves to the position, the locking pin 77 is inserted into the locking limit hole 42 under the action of the second spring 76 to lock and limit the piston sleeve 4, prevent the sudden change of drilling fluid displacement from causing the cutter block 6 to retract and shrink, and finally prevent the cutter block 6 from retracting under low displacement, and reduce the influence of displacement on the retraction of the cutter block 6.

[0083] Furthermore, the entire tool is provided with a limiting mechanism and a locking mechanism 7, wherein the limiting mechanism includes a limiting mechanism formed between the slide groove 61 on the cutter block 6 and the push block 41, and a limiting mechanism formed by the inner inclined surface 225 on the lower outer tube 2, so as to ensure that the cutter block 6 will not be retracted due to external force, and to limit the opening position of the cutter block 6, so as to prevent the outer diameter of the cutter block 6 from being larger than the designed wellbore size when opened. The locking mechanism 7 is used to prevent the cutter block 6 from being retracted and causing the wellbore to shrink due to the movement of the piston sleeve 4 caused by stopping the pump or reducing the displacement after the cutter block 6 is opened in place, thereby ensuring smooth construction.

[0084] Further preferably, the inner wall of the upper end of the piston sleeve 4 is protruding inwardly with a convex ring 43 with a reduced inner diameter; the throttle head 31 can be located in the piston sleeve 4 below the convex ring 43 when the upper end of the lower outer tube 2 is against the upper limit step 111, and can be located in the convex ring 43 when the piston sleeve 4 moves downward to a preset position.

[0085] Reference Figure 5 The inner diameter of the convex ring 43 is d1, and the inner diameter of the piston sleeve 4 below the convex ring 43 is d2, d2 is greater than d1, the inner cavity of the piston sleeve 4 below the convex ring 43 constitutes a primary throttling inner cavity, and the inner cavity of the convex ring 43 constitutes a secondary throttling inner cavity; when the lower end surface of the upper outer tube 1 moves downward and abuts against the lower limit portion 221, the throttling head 31 is located in the piston sleeve 4 below the convex ring 43. At this time, the first gap between the throttling head 31 and the inner wall of the piston sleeve 4 below the convex ring 43 forms a primary throttling. When the piston sleeve 4 moves downward to a preset position under the throttling action, the throttling head 31 is located in the convex ring 43, and the second gap between the throttling head 31 and the inner wall of the convex ring 43 forms a secondary throttling. Since the second gap is smaller than the first gap, the pump pressure at the wellhead will change significantly, thereby accurately judging whether the knife block 6 has been opened to the full position.

[0086] In this way, the upper end of the piston sleeve 4 constitutes a cutter block opening monitoring structure. Through the two-stage variable-size throttle hole, it can judge whether the cutter block 6 is fully opened according to the change of the wellhead pump pressure, thereby realizing the monitoring of the opening position of the cutter block 6, which is simple and convenient.

[0087] In actual application, due to the complex working conditions underground, the piston return spring 45 may fail or the cutter block 6 may not be retracted. In order to force the cutter block 6 to be retracted in this case, a forced recovery mechanism is provided in this embodiment. When the piston return spring 45 fails or the cutter block 6 cannot be retracted, the tool is lifted and the throttle head 31 pulls the piston sleeve 4 upward to a specified position to avoid various situations where the tool cutter block 6 cannot be retracted. The structure of the forced recovery mechanism can be implemented as follows:

[0088] like Figure 3 and Fig.10The upper end of the piston sleeve 4 is connected to a connecting sleeve 5, and a limiting block 51 is connected to the upper end of the connecting sleeve 5. The limiting block 51 is provided with a center hole and a plurality of flow holes 511. The diameter of the throttle head 31 is larger than the aperture of the center hole. The throttling sensing rod 3 can move through the center hole, and the throttle head 31 is located below the limiting block 51.

[0089] The shape of the flow hole 511 on the limit block 51 can also be a waist hole, and the flow hole 511 can also play a certain throttling role, but its main function is to reset the piston sleeve 4 and the knife block 6. The connecting sleeve 5 can be integrally formed with the piston sleeve 4, or can be fixed after being processed separately. The limit block 51 is generally threadedly connected to the inner wall of the upper end of the connecting sleeve 5.

[0090] When the upper return spring fails or the knife block 6 cannot be retracted, lift the tool. When the throttle head 31 abuts against the limit block 51, the throttle head 31 will pull the piston sleeve 4 upward to the specified position to avoid various situations in which the tool knife block 6 cannot be retracted.

[0091] Furthermore, a plurality of nozzle holes 831 are provided in the lower end of the drill bit 8. The nozzle holes 831 can communicate with the inner cavity of the piston sleeve 4 and the outer wall of the lower end of the drill bit 8. The equivalent diameter of the nozzle holes 831 is greater than or equal to 30 mm.

[0092] The nozzle hole 831 adopts a large-sized (equivalent diameter ≥ 30 mm) water eye structure, which can ensure a sufficiently large equivalent diameter while ensuring the rock carrying capacity and facilitating the rapid injection of cement slurry.

[0093] Reference Fig.11 and Fig.12 The drill bit 8 comprises a threaded pipe section 81, a connecting pipe section 82 and a terminal section 83 which are sequentially connected from top to bottom. The terminal section 83 is round-headed. A plurality of blades 84 are circumferentially arranged at intervals on the terminal section 83. Each blade wing 84 extends from the upper end of the terminal section 83 to the center of its lower end. The threaded pipe section 81, the connecting pipe section 82, the terminal section and the blade wing 84 are integrally formed. The lower ends of the blades 84 are connected together at the center of the lower end of the terminal section 83 to increase the strength of the drill bit 8. A chip removal groove 85 is formed between two adjacent blade wings 84. A plurality of nozzle holes 831 are arranged in the terminal section 83. The nozzle holes 831 can communicate with the inner cavity of the connecting pipe section 82 and the corresponding chip removal groove 85. A front row of teeth 86 and a rear row of teeth 87 can be set on the blade wing 84, and the rear row of teeth 87 can be selected from plane teeth, non-plane teeth, conical teeth, carbide teeth, etc.; the number of blade wings 84 and water holes is matched, and can be set to five, six or seven, etc.; for example, in this embodiment, five blade wings 84 and three water holes are provided.

[0094] In order to facilitate processing and installation, the upper outer tube 1 includes an upper joint 11 and an outer movable sleeve 12 connected up and down, and the lower outer tube 2 includes an inner movable sleeve 21, an outer tube 22 and a lower joint 23 connected in sequence from top to bottom. The lower end outer wall of the upper joint 11 is threadedly connected to the upper end inner wall of the outer movable sleeve 12, and the lower end surface of the upper joint 11 constitutes an upper limit step 111, and the lower limit step 121 is formed on the lower end inner wall of the outer movable sleeve 12; the upper end outer wall of the inner movable sleeve 21 forms a limiting ring, which can be against the upper limit step 111 or against the lower limit step 121; the upper end of the throttling sensing rod 3 is connected to the upper joint 11, and the lower part thereof is penetrated in the inner movable sleeve 21; the knife block 6 is installed on the outer tube 22, the piston sleeve 4 is arranged in the outer tube 22, and the bottom end of the lower joint 23 is connected to the drill bit 8.

[0095] The components in the upper outer tube 1 and the lower outer tube 2 can be connected by threads, the lower end outer wall of the inner moving sleeve 21 is threadedly connected to the upper end inner wall of the outer tube 22, and the lower end inner wall of the outer tube 22 is threadedly connected to the upper end outer wall of the lower joint 23. The above-mentioned mounting block 112 is fixedly arranged in the upper joint 11, and the throttling sensing rod 3 is connected to the upper joint 11, and passes through the outer moving sleeve 12 and is suspended inside the tool; when the tool does not touch the bottom of the well 9, due to the deadweight of the tool, the inner moving sleeve 21 and the outer tube 22, the piston sleeve 4 and the knife block 6 are suspended below the outer moving sleeve 12; when the tool touches the bottom of the well 9 and continues to pressurize, the inner moving sleeve 21 moves upward and "squeezes" into the outer moving sleeve 12, so that the throttling head 31 enters the piston sleeve 4; and in the process of the outer moving sleeve 12 descending relative to the inner moving sleeve 21, it will push the locking push rod 71 to move, so as to achieve locking after the knife block 6 is opened.

[0096] The lower end surface of the limiting ring constitutes the upper limit portion 122 mentioned above, the upper end surface of the outer cylinder 22 constitutes the lower limit portion 221 mentioned above, the axial mounting hole 226 and the radial mounting hole are both provided in the side wall of the outer cylinder 22, the mounting port 223 is provided on the side wall of the outer cylinder 22, and the knife seat 224 is fixedly connected to the outer cylinder 22. A stop ring 231 is formed on the inner wall of the upper end of the lower joint 23. When the piston sleeve 4 moves downward to a preset position, the lower end of the piston sleeve 4 abuts against the stop ring 231 to limit the downward movement of the piston sleeve 4. Generally, the outer movable sleeve 12 and the inner movable sleeve 21 are both hexagonal sleeves (the cross section of the outer wall is a regular hexagon) for easy installation.

[0097] Furthermore, the present application also provides a drilling tool assembly, which includes the above-mentioned mechanical hydraulic type continuous plugging drilling tool, check valve, drill collar, weighted drill pipe and drill pipe respectively connected from bottom to top. The outer diameter of the drill bit 8 should be consistent with the drill pipe, and its size is smaller than the borehole size; each blade wing 84 will be provided with a back-scoring tooth, and the smaller outer diameter of the drill bit 8 can effectively avoid suction when the drilling fluid needs to be quickly withdrawn during cement slurry injection, and the back-scoring structure of the blade wing 84 is also conducive to the removal of the drill bit 8 when it is not withdrawn from the cementing well bottom 9 in time.

[0098] Furthermore, the present application also provides a mechanical hydraulic continuous plugging drilling method, which uses the above-mentioned tool to perform the operation. The specific construction method includes the following steps:

[0099] Step 1: calibrate the primary throttling and secondary throttling pressure differences of the cutter block opening monitoring mechanism at the wellhead; and test the opening and retracting functions of the cutter block 6 in the mechanical-hydraulic continuous plugging drilling tool.

[0100] Step 2: Assemble the drilling tools, and lower the mechanical hydraulic continuous plugging drilling tool to the plugging target layer, and pull it up several meters after probing the bottom.

[0101] Step 3: Start grouting construction. After the cement slurry is injected, switch to the drilling circulation pipeline, start the pump to inject drilling fluid to replace the cement slurry in the drill bit. After the cement slurry replacement operation is completed, pull the drill to a safe position.

[0102] Step 4: Turn on the pump to circulate the drilling fluid, flush and clean the mechanical hydraulic continuous plugging drilling tool for 5 minutes, and wait for solidification after completing the flushing operation.

[0103] Step 5: After the cement slurry is solidified, the mechanical hydraulic continuous plugging drilling tool is lowered to the cement slurry solidification surface again. When the drilling pressure rises to the designed value, the drilling is stopped. At this time, the tool contacts the bottom of the well 9 and still has drilling pressure. Under the action of drilling pressure, the inner movable sleeve 21 is "squeezed" into the outer movable sleeve 12, and the throttle head 31 enters the primary throttling cavity of the piston sleeve 4. When the pump is turned on and the displacement is increased to the working displacement, the first pump pressure is recorded. The hydraulic force generated by the primary throttling cavity pushes the piston sleeve 4 downward, and the corresponding three push blocks 41 on the piston open the cutter block 6. The piston sleeve 4 moves downward to the maximum stroke position, and the pump pressure increases significantly, indicating that the throttle head 31 enters the secondary throttling cavity of the piston sleeve 4, and the cutter block 6 has been fully opened to the designed wellbore size. At this time, the cutter block 6 is limited and locked. The drilling parameters are adjusted to the working drilling pressure and rotation speed, and drilling and plugging are started. The difference between the above-mentioned continuous plugging-drilling operation and the conventional plugging-drilling operation is that there is no need to replace the drilling bit 8 when drilling, so that overflow caused by suction and hollowing during the drilling process can be avoided.

[0104] Step 6: After the plugging is completed, the drill is pulled out of the bottom of the well 9, and drilling fluid is injected to seal the well and hold the pressure to check whether the plugging is successful. If the plugging is successful, the drilling parameters can be changed according to the drilled formation to continue drilling.

[0105] Step 7: If the plugging is unsuccessful, repeat the above steps 3 to 6 until the plugging is successful, so as to achieve multiple plugging and drilling operations without starting drilling and replacing drilling tools.

[0106] The whole tool and method realize continuous plugging-drilling-drilling operation without drilling. The tool is mainly composed of a drill bit 8 with a large diameter structure and a telescopic variable diameter unit with a variable diameter active throttling structure. The telescopic variable diameter unit includes the above-mentioned upper outer tube 1, lower outer tube 2, throttling sensing rod 3, throttling head 31, piston sleeve 4, knife block 6, locking mechanism 7, etc. The telescopic variable diameter unit has two extreme equivalent diameters. The maximum diameter can be used for large-volume cement slurry injection, and the minimum diameter forms throttling to push out the knife block 6 and cooperate with the drill bit 8 to complete the drilling and plugging operation. The tool can actively switch between the two extreme equivalent diameters in conjunction with simple on-site operations to realize free switching of plugging and drilling and plugging operations under grouting conditions and drilling and plugging conditions in oil drilling cement plugging operations, and realize continuous completion of multiple cement plugging operations without drilling in multiple leaking layers; at the same time, a locking mechanism 7 and a knife block opening monitoring structure are provided to ensure that the tool knife block 6 is fully opened to the designed wellbore size. Among them, the grouting condition can replace the bare drill rod to complete the cement injection plugging operation, and the drilling plugging condition can replace the roller drill bit drilling plugging operation and the PDC drill bit replacement drilling operation.

[0107] The drill bit 8 of the tool is used as a pilot drill bit, and its outer diameter is consistent with that of the drill pipe. It is different from conventional plug drill bits in the condition of cement slurry injection. It can effectively avoid the suction phenomenon when the drilling fluid is quickly withdrawn. At the same time, it is convenient to remove the drill bit 8 when it is not withdrawn from the cementing bottom 9 in time. In addition, the drill bit 8 can be customized and designed according to the mechanical properties of the new formation rock and meet the conditions of drilling plugs to perform new formation drilling operations; the telescopic variable diameter unit can form a larger equivalent diameter under grouting conditions to ensure the rapid injection of large displacement of cement slurry. Under the condition of drilling plugs, the tool adopts the "mechanical + hydraulic" form to push out the cutter block 6, and designs an active throttling structure with the throttling sensing rod 3 as the core. The hydraulic action generated by the active throttling is used to realize the telescopic diameter change of the cutter block 6, and the pilot hole size of the drill bit 8 is expanded to the specified full hole size for drilling plug operations. The tool can realize continuous switching between grouting and drilling by simple drilling operation of controlling drilling pressure and displacement, replacing conventional cement plugging and drilling operation to realize single-layer or even multi-layer plugging-drilling-drilling operation without drilling. The tool has a simple structure and is easy to implement. The matching plugging and drilling operation method effectively shortens the plugging and drilling operation cycle, which has great economic value.

[0108] The above are only exemplary embodiments of the present invention and are not intended to limit the scope of the present invention. Any equivalent changes and modifications made by any person skilled in the art without departing from the concept and principle of the present invention shall fall within the scope of protection of the present invention.

Claims

1. A mechanical hydraulic continuous plugging drilling tool, characterized in that: include: The upper outer tube is arranged vertically, and the inner wall of the lower part thereof is provided with an upper limit step and a lower limit step; A vertically arranged lower outer tube, the upper end of which can move up and down inside the upper outer tube and between the upper limit step and the lower limit step, and can be suspended on the lower limit step under the action of gravity; a plurality of knife blocks that can be opened outwards are arranged at intervals in the circumferential direction of the inner side wall of the lower part; A throttling sensing rod, the upper end of which is connected to the upper outer tube and the lower end of which can extend into the lower outer tube; A piston sleeve, which is movable up and down and is disposed in the lower outer tube and is located below the throttling sensing rod, and a plurality of push blocks are provided at intervals in the circumferential direction on the outer wall of the piston sleeve; a drill bit connected to the bottom end of the lower outer tube; Among them, the throttling sensing rod can move downward and be inserted into the piston sleeve to reduce the equivalent diameter of the piston sleeve when the upper end of the lower outer tube is against the upper limit step, so as to cause throttling of the liquid injected into the piston sleeve and push the piston sleeve to move downward to a preset position, and the push block pushes the corresponding knife block outward, and the knife block opens outward; the piston sleeve can move upward and reset after the liquid stops being injected, and retract the knife block inward into the side wall of the lower outer tube.

2. The mechanical hydraulic continuous leak plugging drilling tool as claimed in claim 1 is characterized in that: An upper stop is provided on the outer wall of the piston sleeve, a lower stop is provided on the inner wall of the lower outer tube, a piston return spring is provided on the outer sleeve of the piston sleeve, and two ends of the piston return spring respectively abut between the upper stop and the lower stop.

3. The mechanical hydraulic continuous leak plugging drilling tool as claimed in claim 1 is characterized in that: A slide groove is provided on the inner side of the blade block, and the slide groove includes an inclined groove and a flat groove connected up and down, the bottom groove wall of the inclined groove is an inner inclined surface, and the groove wall of the flat groove is a plane; The lower outer wall of the push block is an outer inclined surface, and the upper outer wall thereof is a vertical plane. The shape of the inclined groove matches the shape of the push block. When the piston sleeve moves downward to a preset position, the push block can be inserted into the flat groove and the vertical plane fits with the groove wall of the flat groove.

4. The mechanical hydraulic continuous leak plugging drilling tool as claimed in claim 1 is characterized in that: The outer wall of the lower outer tube is provided with a plurality of mounting openings in the circumferential direction, and the upper end of each of the blade blocks is connected to the lower outer tube via a rotating shaft, and the axial direction of the rotating shaft is perpendicular to the axial direction of the lower outer tube; An inner bevel is provided on the inner wall of the lower outer tube and adjacent to the lower position of the installation opening, and an outer bevel is provided on the lower end surface of the knife block. The outer bevel can abut against the inner bevel after the knife block is opened outward.

5. The mechanical hydraulic continuous leak plugging drilling tool as claimed in claim 1, characterized in that: A locking push rod that can elastically move up and down and a locking push rod that can elastically move radially are provided in the side wall of the lower outer tube, the lower end of the locking push rod has an upper inclined surface, the locking push rod is located below the locking push rod and has a lower inclined surface that can cooperate with the upper inclined surface, and the upper inclined surface can abut against the lower inclined surface; a locking limit hole is provided on the outer wall of the piston sleeve, and when the upper end of the lower outer tube abuts against the upper limit step, the lower end surface of the upper outer tube can push the locking push rod to move downward, so that the locking push rod is inserted into the locking limit hole when the piston sleeve moves down to a preset position.

6. The mechanical hydraulic continuous leak plugging drilling tool as claimed in claim 5, characterized in that: An upper outer wall of the lower outer tube is provided with an upper limit portion and a lower limit portion, the lower end of the upper outer tube can move between the upper limit portion and the lower limit portion, the upper end of the locking push rod can extend upward from the lower limit portion, and the lower end surface of the upper outer tube can push the locking push rod to move downward when it moves downward and abuts against the lower limit portion; an axial mounting hole and a radial mounting hole are provided in the side wall of the lower outer tube, the upper end of the axial mounting hole passes through the lower limit portion upward, and the radial mounting hole is aligned with the axial mounting hole The lower end of the mounting hole is connected to and radially penetrates the inner wall of the outer tube; the first end of the axial mounting hole is formed with a stepped hole with an increased aperture, a plug is installed in the end of the stepped hole, the upper end of the locking push rod can move up and down through the plug, the upper outer wall of the locking push rod has an annular first flange, the first flange is located below the plug, the locking push rod outer sleeve is provided with a locking return spring, and the two ends of the locking return spring are respectively pressed against the first flange and the bottom hole shoulder of the stepped hole; A mounting sleeve is provided in the radial mounting hole, and the locking push rod includes a push column and a locking pin provided in the mounting sleeve, the push column is formed with the lower inclined surface, and the lower end of the locking push rod can extend into the mounting sleeve and abut against the lower inclined surface; an annular second flange is provided on the upper outer wall of the push column, a first spring is clamped between the second flange and the step in the mounting sleeve, a second spring is provided between the push column and the locking pin, and the locking pin can extend radially inward and be inserted in the locking limit hole.

7. The mechanical hydraulic continuous leak plugging drilling tool as claimed in claim 1, characterized in that: The lower end of the throttling sensing rod is connected with a throttling head, the diameter of the throttling head is larger than the diameter of the throttling sensing rod, and the throttling head can be moved into the piston sleeve.

8. The mechanical hydraulic continuous leak plugging drilling tool as claimed in claim 7, characterized in that: The inner wall of the upper end of the piston sleeve is protruding inwardly with a convex ring with a reduced inner diameter; the throttle head can be located in the piston sleeve below the convex ring when the upper end of the lower outer tube is against the upper limit step, and can be located in the convex ring when the piston sleeve moves downward to a preset position.

9. The mechanical hydraulic continuous leak plugging drilling tool as claimed in claim 7, characterized in that: The upper end of the piston sleeve is connected to a connecting sleeve, and the upper end of the connecting sleeve is connected to a limiting block. The limiting block is provided with a center hole and a plurality of flow holes. The diameter of the throttling head is larger than the aperture of the center hole. The throttling sensing rod can move through the center hole, and the throttling head is located below the limiting block.

10. The mechanical hydraulic continuous leak plugging drilling tool according to claim 1, characterized in that: A plurality of nozzle holes are arranged in the lower end of the drill bit, and the nozzle holes can communicate with the inner cavity of the piston sleeve and the outer wall of the lower end of the drill bit, and the equivalent diameter of the nozzle holes is greater than or equal to 30 mm.

11. The mechanical hydraulic continuous leak plugging drilling tool according to claim 1, characterized in that: The upper outer tube comprises an upper joint and an outer movable sleeve connected up and down, and the lower outer tube comprises an inner movable sleeve, an outer tube and a lower joint connected in sequence from top to bottom, the lower end outer wall of the upper joint is threadedly connected with the upper end inner wall of the outer movable sleeve, the lower end surface of the upper joint constitutes the upper limit step, and the lower limit step is formed on the lower end inner wall of the outer movable sleeve; the upper end outer wall of the inner movable sleeve forms a limit ring, and the limit ring can abut against the upper limit step or the lower limit step; The upper end of the throttling sensing rod is connected to the upper joint, and the lower part thereof is inserted into the inner movable sleeve; the knife block is installed on the outer cylinder, the piston sleeve is arranged in the outer cylinder, and the bottom end of the lower joint is connected to the drill bit.

12. A mechanical hydraulic continuous plugging drilling method, characterized in that: The mechanical hydraulic continuous plugging drilling method comprises: Connecting a drill pipe and the mechanical hydraulic continuous leak plugging drilling tool as described in any one of claims 1 to 11 to form a drilling tool assembly, and lowering the mechanical hydraulic continuous leak plugging drilling tool to the leak plugging target layer; Start grouting construction. After the cement slurry is injected, start the pump to inject drilling fluid to replace the cement slurry in the drilling tool assembly. After the cement slurry replacement operation is completed, pull the drill to a safe position; After the cement slurry is solidified, the mechanical hydraulic continuous plugging drilling tool is made to touch the bottom of the well and continue to be pressurized. Under the action of drilling pressure, the lower end of the throttling sensing rod enters the piston sleeve to reduce the equivalent diameter of the piston sleeve, and the pump is turned on to the designed displacement. The hydraulic thrust generated between the piston sleeve and the lower end of the throttling sensing rod pushes the piston sleeve to move downward, and the push block pushes the knife block to open outward, and the drilling and plugging construction begins; After the plugging is completed, the drill is pulled out from the bottom of the well, drilling fluid is injected, the well is sealed and the pressure is held down to check whether the plugging is successful; If the plugging is unsuccessful, repeat the grouting and drilling until the plugging is successful; Carry out drilling operations.

Images