Micropore drilling tool

Abstract

The invention provides a micropore drilling tool which comprises a suspension packer, an oil drainage pipe, a perforation pup joint and a guide shoe, the suspension packer comprises a first sealing rubber sleeve and a slip mechanism, and the first sealing rubber sleeve and the slip mechanism can radially expand to seal an annular space and suspend and anchor respectively; the guide shoe is provided with a guide shoe channel communicated with the annular space, and the guide shoe can close the guide shoe channel under the action of ball throwing and pressure; the oil drainage pipe is provided with a communicating structure for communicating the annulus with the inner cavity of the pipe column; the perforation short section comprises a perforation hydraulic cylinder, a perforation piston, an injection pipe and a guide wedge block, the perforation hydraulic cylinder is communicated with an inner cavity of the tubular column, the injection pipe is connected to the perforation piston, and the perforation piston is installed in the perforation hydraulic cylinder and can drive the injection pipe to move under the hydraulic action in the perforation hydraulic cylinder; the injection pipe can extend out in the radial direction under the guiding effect of the guiding wedge block. And moreover, the injection pipe is communicated with the perforation hydraulic cylinder, so that the technical problems that a working pipe column needs to be tripped for multiple times in radial drilling and the construction period is relatively long are solved.

Description

Technical Field

[0001] The invention relates to the technical field of oil and gas field drilling and completion engineering, and in particular to a micro-hole drilling tool. Background Art

[0002] After the oil field enters the middle and late stages of development, the formation pressure in the old blocks gradually depletes, the oil reservoirs encountered become increasingly complex, and the pollution to the reservoirs during the drilling process becomes more and more serious. For low-grade oil reservoirs such as low permeability and thin layers, low-grade oil reservoirs cannot be economically and effectively exploited without taking measures to increase production. Therefore, this puts forward new and higher requirements for completion and production increase technologies.

[0003] The penetration distance of conventional perforation is generally 0.4m to 1m, which cannot effectively penetrate the contaminated zone. There is also a compaction effect, causing secondary damage. The permeability around the blasthole is reduced by 70% to 80%, seriously restricting the oil well production.

[0004] Acidizing (or acid fracturing) and fracturing are effective technical means for the transformation of low permeability oil and gas reservoirs, and have played an important role in increasing the production of single wells. However, there are the following problems: the fractures are affected by the ground stress and extend along the direction of the maximum principal stress. In heterogeneous reservoirs and reservoirs with faults, the fracture initiation position and direction are uncontrollable, which reduces the accuracy and effectiveness of reservoir transformation; when there are mud barriers / interlayers in the vertical direction of the reservoir, the fractures cannot effectively penetrate, resulting in a limited range of vertical reservoir transformation; stable fractures cannot be formed in coalbed methane, the communication capacity is limited, and the desorption range of coalbed methane is limited. Therefore, acidizing or fracturing is difficult to effectively increase production in fractured oil reservoirs, heterogeneous reservoirs, coalbed methane reservoirs, etc.

[0005] Radial drilling technology can drill multiple radial micro-horizontal holes in the same or different layers in the formation, so as to remove formation pollution, expand the drainage area (oil / gas wells) or the affected area (water injection / gas wells), connect the remaining oil and gas enrichment areas, and improve the well network. However, this technology requires the construction of each hole to be completed in sequence, and a single well needs to repeatedly trip the working string. The construction period is relatively long, which seriously restricts the development and promotion of the technology. Summary of the invention

[0006] The purpose of the present invention is to provide a micro-hole drilling tool to solve the technical problem that radial drilling requires multiple trips of the working pipe string and the construction period is relatively long.

[0007] The above-mentioned purpose of the present invention can be achieved by adopting the following technical solutions:

[0008] The present invention provides a micro-hole drilling tool, comprising: a hanging packer, an oil drain pipe, a perforating nipple and a guide shoe, wherein the hanging packer comprises a first sealing rubber tube and a slip mechanism, wherein the first sealing rubber tube and the slip mechanism can respectively expand radially under the action of ball throwing and pressure to seal the annulus and suspend the anchor; the guide shoe is provided with a guide shoe channel connected to the annulus, and the guide shoe can close the guide shoe channel under the action of ball throwing and pressure; the oil drain pipe is provided with a connecting structure for connecting the annulus with the inner cavity of the pipe string;

[0009] The perforating sub includes a perforating hydraulic cylinder, a perforating piston, an injection pipe and a guide wedge. The perforating hydraulic cylinder is communicated with the inner cavity of the pipe string. The injection pipe is connected to the perforating piston. The perforating piston is installed in the perforating hydraulic cylinder and can drive the injection pipe to move under the hydraulic action in the perforating hydraulic cylinder. The injection pipe can be radially extended under the guiding action of the guide wedge; and the injection pipe is communicated with the perforating hydraulic cylinder.

[0010] In a preferred embodiment, the micro-hole drilling tool includes an open hole packer, which includes a second sealing rubber cylinder, a second piston cylinder and a second piston cylinder. The second piston cylinder is connected to the inner cavity of the tubing string, and the second piston cylinder is installed in the second piston cylinder and can move under the hydraulic action in the second piston cylinder and drive the second sealing rubber cylinder to expand outward.

[0011] In a preferred embodiment, a piston ring for abutting against the second sealing rubber cylinder is disposed at the end of the second piston cylinder; a plurality of the second sealing rubber cylinders are distributed along the axial direction, and a second spacer ring is disposed between adjacent second sealing rubber cylinders.

[0012] In a preferred embodiment, the open hole packer includes a second adjustment ring, a second center tube, a second upper joint connected to the upper end of the second center tube, and a second lower joint connected to the lower end of the second center tube. The second sealing rubber tube, the second piston cylinder and the second piston tube are all arranged outside the second center tube, the piston tube is arranged axially, and the second adjustment ring is threadedly connected to the outside of the second lower joint and is located below the second sealing rubber tube.

[0013] In a preferred embodiment, the micro-hole drilling tool includes a naked hole straightener, which includes a straightening block, a third piston cylinder and a third piston tube. The third piston cylinder is connected to the inner cavity of the tubing string. The third piston tube is installed in the third piston cylinder and can move under the hydraulic action in the third piston cylinder and drive the straightening block to expand radially.

[0014] In a preferred embodiment, the open hole straightener includes a straightening cone, the conical surface of the straightening cone cooperates with the straightening block, the third piston cylinder can move axially and drive the straightening block radially through the straightening cone. In a preferred embodiment, the perforating short section includes a nozzle and a bursting piece, the nozzle is connected to the front end of the injection pipe, the bursting piece is fixed in front of the nozzle, and the nozzle can break through the bursting piece under the drive of the injection pipe.

[0015] In a preferred embodiment, the perforating sub includes a sealing block and a sealing ring, the sealing block is provided with an upper mounting cavity with an opening facing upward and a lower mounting cavity with an opening facing downward, the perforating hydraulic cylinder is at least partially arranged in the upper mounting cavity, the bursting disc and the sealing ring are both installed in the lower mounting cavity, the bursting disc is located below the sealing ring, and the injection pipe passes through the sealing ring and is sealed.

[0016] In a preferred embodiment, the perforating sub includes a first central tube, the perforating hydraulic cylinder and the guide wedge are both arranged outside the first central tube, the perforating hydraulic cylinder is arranged axially, and the guide wedge is provided with a wedge slope for guiding the injection pipe and the nozzle.

[0017] In a preferred embodiment, the perforating sub includes a first adjusting ring, a first upper joint connected to the upper end of the first center pipe, and a first lower joint connected to the lower end of the first center pipe, the first adjusting ring is sleeved on the outside of the first center pipe and screwed to the first lower joint, and the first adjusting ring is located below the guide wedge.

[0018] In a preferred embodiment, the perforating sub comprises a guide ring, the guide ring is provided with an axial groove, and the guide wedge is installed in the axial groove and fixedly connected by a positioning pin.

[0019] In a preferred embodiment, the oil drain pipe comprises a main body, and a drain hole is provided on the pipe wall of the main body;

[0020] The connecting structure includes a valve seat, a blocking ball and a first supporting spring. The valve seat is installed on the leakage hole. The first supporting spring can drive the blocking ball to abut against the valve seat to close the leakage hole through the pipe wall. Moreover, the blocking ball can overcome the elastic force of the first supporting spring and leave the valve seat to open the leakage hole under the hydraulic action in the annulus.

[0021] In a preferred embodiment, the oil drain pipe includes a third upper joint, a positioning joint, an oil drain nipple and a third lower joint connected in sequence, the oil drain nipple is provided with an external oil leakage groove, and the inner wall of the positioning joint is provided with a first limiting groove; the connecting structure includes a movable inner cylinder, the movable inner cylinder is arranged in the positioning joint, the outer wall of the movable inner cylinder is provided with a positioning protrusion, the inner wall of the movable inner cylinder is provided with a first internal step portion, the movable inner cylinder is provided with an internal oil leakage groove, the movable inner cylinder can move downward when the first internal step portion is subjected to a downward thrust, and move until the internal oil leakage groove is aligned with the external oil leakage groove, and at the same time the positioning protrusion is stuck in the first limiting groove.

[0022] In a preferred embodiment, the movable inner cylinder includes a locking retaining spring and an inner cylinder body distributed from top to bottom, the positioning protrusion is arranged on the locking retaining spring, and the first internal step portion and the internal oil leakage groove are both arranged on the inner cylinder body; the oil leakage pipe includes a first casing arranged on the inner side of the positioning joint, the first casing sleeve is fixedly connected to the third upper joint, and the locking retaining spring is arranged between the first casing and the positioning joint.

[0023] In a preferred embodiment, the inner wall of the inner cylinder body is provided with a lower limit groove located below the inner oil leakage groove, and the first internal step portion is formed at the lower boundary of the lower limit groove.

[0024] In a preferred embodiment, the inner wall of the inner cylinder body is provided with a middle limit groove located above the inner oil leakage groove, and the upper boundary of the middle limit groove forms a second inner step portion.

[0025] In a preferred embodiment, the micro-hole drilling tool includes a sleeve switch tool, which includes a sleeve center axis, a switch block and a second support spring. The switch block is installed on the sleeve center axis and can move radially. The second support spring is connected to the switch block to drive the switch block to have a tendency to move radially outward, and the switch block can be stuck in the lower limit groove.

[0026] In a preferred embodiment, the suspension packer includes a fifth upper joint, a locking shaft, a first hydraulic cylinder, a first piston cylinder and a ball seat, and the ball seat is connected to the inner side of the fifth upper joint through a first shear pin; the locking shaft is sleeved outside the fifth upper joint, and the first sealing rubber tube is sleeved outside the locking shaft; the first hydraulic cylinder and the first piston cylinder are sleeved outside the fifth upper joint and are located above the first sealing rubber tube; the fifth upper joint is provided with a first hydraulic through hole connecting the inner cavity of the pipe column with the first hydraulic cylinder; the ball seat blocks the first hydraulic through hole and can deviate from the first hydraulic through hole under the action of throwing a ball.

[0027] In a preferred embodiment, the slip mechanism includes a slip and a slip wedge ring sleeved outside the locking shaft, and the slip wedge ring is arranged below the first sealing rubber cylinder and cooperates with the slip through an inclined surface.

[0028] The characteristics and advantages of the present invention are:

[0029] After the micro-hole drilling tool is lowered into the predetermined position in the well, it is suspended and fixed on the upper casing through the tail pipe suspension packer and the annulus is sealed; the pumping pressure is increased, the pressure in the inner cavity of the pipe string exceeds the activation pressure of the perforating short section, and the injection pipe and the nozzle begin to extend outward and break the rock, forming micro-holes with high conductivity in the reservoir; after the construction is completed, the injection pipe remains in the micro-hole to support the well wall; the oil leakage pipe is opened to allow the formation fluid to flow from the outside of the pipe string into the pipe string, and then the oil and gas production operation is carried out. The micro-hole drilling tool can be provided with multiple oil leakage pipes or multiple perforating short sections as needed to selectively arrange multiple micro-channels in the reservoir. Through the micro-hole drilling tool, multiple micro-channels can be selectively arranged in the reservoir according to demand, and the penetration distance is long and there is no compaction effect, so as to achieve the purpose of increasing the contact area of ​​the reservoir, connecting the natural fractures of the reservoir, etc., thereby increasing the single well production and recovery rate, and shortening the construction period. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0031] Figure 1 An overall schematic diagram of the micro-hole drilling tool provided by the present invention;

[0032] Figure 2 A schematic diagram of the structure of the guide shoe in the micro-hole drilling tool provided by the present invention;

[0033] Figure 3 A schematic diagram of the structure of a perforating sub in a micro-hole drilling tool provided by the present invention;

[0034] Figure 4 A schematic structural diagram of an embodiment of an oil drain pipe in a micro-hole drilling tool provided by the present invention;

[0035] Figure 5 A schematic structural diagram of another embodiment of an oil drain pipe in a micro-hole drilling tool provided by the present invention;

[0036] Figure 6 A schematic diagram of the structure of a sleeve switch tool in a micro-hole drilling tool provided by the present invention;

[0037] Figure 7 A schematic diagram of the structure of an open hole packer in a micro-hole drilling tool provided by the present invention;

[0038] Figure 8 A schematic diagram of the structure of an open hole centralizer in a micro-hole drilling tool provided by the present invention;

[0039] Fig. 9 A schematic diagram of the structure of a suspension packer in a micro-hole drilling tool provided by the present invention;

[0040] Fig.10 A schematic structural diagram of the fifth upper joint in the micro-hole drilling tool provided by the present invention;

[0041] Fig. 10A for Fig.10 a bottom view of the fifth upper joint shown;

[0042] Fig.11 A schematic diagram of the structure of the slip seat in the micro-hole drilling tool provided by the present invention;

[0043] Fig.11A for Fig.11 Bottom view of the slip seat shown;

[0044] Fig.12 A schematic diagram of the drilling state of the micro-hole drilling tool provided by the present invention;

[0045] Fig.13 for Fig.12 Cross-section of

[0046] Fig.14 for Figure 3 A local enlarged view of point A in FIG.

[0047] Fig.15 for Figure 4 A local enlarged view of point B in FIG.

[0048] Fig.16 for Figure 5 A local enlarged view of point C in FIG.

[0049] Fig.17 for Figure 5 A local enlarged view of point D in FIG.

[0050] Description of Figure Numbers:

[0051] 1. Guide shoe; 2. Perforating nipple; 3. Oil drain pipe; 4. Open hole packer;

[0052] 5. casing; 51. inner cavity of tubular column;

[0053] 6. Tail pipe hanging packer;

[0054] 71. Radial channel; 72. Natural fracture; 73. Contaminated zone; 74. Main wellbore;

[0055] 11. Seventh upper joint; 12. Intermediate sleeve; 13. Seventh lower joint; 14. Guide shoe body; 141. Guide shoe channel;

[0056] 15. Guide shoe center axis; 16. Limit ring; 17. Sealing ring; 18. Shear pin;

[0057] 21. First upper joint; 22. Current sleeve; 23. First center tube;

[0058] 24. Perforating hydraulic cylinder; 25. Sealing ring; 26. Casing;

[0059] 27. Perforating piston; 28. Injection pipe;

[0060] 29. Sealing block; 291. Upper mounting cavity; 292. Lower mounting cavity;

[0061] 210, sealing ring;

[0062] 211. Nozzle; 212. Bursting disc; 213. Retaining ring;

[0063] 214, guide ring; 215, guide wedge; 220, wedge inclined surface;

[0064] 216, positioning pin;

[0065] 217, first adjustment ring; 218, first lower joint;

[0066] 31. Subject;

[0067] 32. Valve core; 33. First supporting spring; 34. Valve seat; 35. Sealing ring; 36. Blocking ball;

[0068] 37. The third upper joint; 38. The positioning joint; 381. The first limiting groove;

[0069] 39. Oil drain nipple; 391. External oil drain tank;

[0070] 310, third lower joint;

[0071] 311, first casing; 312, sealing ring;

[0072] 300, movable inner cylinder; 313, locking claw spring; 3131, positioning protrusion; 314, inner cylinder body; 3141, inner leakage oil groove; 3142, first inner step portion; 3143, lower limit groove; 3144, second inner step portion; 3145, middle limit groove;

[0073] 315, limit screw;

[0074] 316, fourth upper joint; 321, fourth lower joint;

[0075] 317, central axis of the sliding sleeve; 318, sealing ring; 319, switch block; 320, second supporting spring;

[0076] 41. second upper joint; 42. second central tube; 415. second lower joint;

[0077] 43. Second piston cylinder; 44. Sealing ring; 45. Second piston cylinder;

[0078] 46. ​​Wedge ring; 47. Locking ring; 48. Retaining ring;

[0079] 49. Shear screw;

[0080] 410, piston ring;

[0081] 411, second sealing rubber cylinder; 412, rubber cylinder shoulder guard; 413, spacer ring;

[0082] 414, second adjustment ring;

[0083] 416, sixth upper joint; 417, center tube;

[0084] 418, third piston cylinder; 419, sealing ring; 420, third piston cylinder;

[0085] 421, wedge ring; 422, locking ring; 423, retaining ring; 424, shear pin;

[0086] 425, righting cone; 426, righting block;

[0087] 427, third adjustment ring; 428, sixth lower joint;

[0088] 61. fifth upper joint; 60. first hydraulic through hole; 601. locking claw spring;

[0089] 62. A first hydraulic cylinder; 63. A first fixing screw;

[0090] 64. Sealing ring;

[0091] 65. ball seat; 66. first piston cylinder;

[0092] 67. First shear pin; 68. Second shear pin;

[0093] 69. Locking sleeve; 610. Locking ring; 611. Locking shaft;

[0094] 612, shoulder guard; 613, first sealing rubber tube; 614, spacer ring;

[0095] 615, slip wedge ring; 616, slip; 617, slip seat; 6171, slip seat limiting groove; 618, second fixing screw;

[0096] 619, support ring; 620, retaining ring; 621, third fixing screw. DETAILED DESCRIPTION

[0097] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0098] The present invention provides a micro-hole drilling tool, such as Figure 1-Figure 9 As shown, it includes: a hanging packer, an oil drain pipe, a perforating nipple and a guide shoe. The hanging packer includes a first sealing rubber tube and a slip mechanism. The first sealing rubber tube and the slip mechanism can expand radially under the action of ball throwing and pressure to seal the annulus and suspend the anchor respectively; the guide shoe is provided with a guide shoe channel 141 connected to the annulus, and the guide shoe can close the guide shoe channel 141 under the action of ball throwing and pressure; the oil drain pipe is provided with a connecting structure for connecting the annulus with the inner cavity 51 of the tubing string; the perforating nipple includes a perforating hydraulic cylinder, a perforating piston, an injection pipe and a guide wedge. The perforating hydraulic cylinder is connected to the inner cavity of the tubing string, the injection pipe is connected to the perforating piston, the perforating piston is installed in the perforating hydraulic cylinder, and can drive the injection pipe to move under the hydraulic action of the perforating hydraulic cylinder, and the injection pipe can be radially extended under the guiding action of the guide wedge; and the injection pipe is connected to the perforating hydraulic cylinder.

[0099] After the micro-hole drilling tool is lowered into the predetermined position in the well, it is suspended and fixed on the upper casing through the tail pipe suspension packer and the annulus is sealed; the pumping pressure is increased, the pressure in the inner cavity of the pipe string exceeds the activation pressure of the perforating short section, and the injection pipe and the nozzle begin to extend outward and break the rock, forming micro-holes with high conductivity in the reservoir; after the construction is completed, the injection pipe remains in the micro-hole to support the well wall; the oil leakage pipe is opened to allow the formation fluid to flow from the outside of the pipe string into the pipe string, and then the oil and gas production operation is carried out. The micro-hole drilling tool can be provided with multiple oil leakage pipes or multiple perforating short sections as needed to selectively arrange multiple micro-channels in the reservoir. Through the micro-hole drilling tool, multiple micro-channels can be selectively arranged in the reservoir according to demand, and the penetration distance is long and there is no compaction effect, so as to achieve the purpose of increasing the contact area of ​​the reservoir, connecting the natural fractures of the reservoir, etc., thereby increasing the single well production and recovery rate, and shortening the construction period.

[0100] In one embodiment, the micro-hole drilling tool includes an open hole packer, which includes a second sealing rubber cylinder, a second piston cylinder and a second piston cylinder, wherein the second piston cylinder is connected to the inner cavity of the tubing string, the second piston cylinder is installed in the second piston cylinder, and can move under the hydraulic pressure in the second piston cylinder and drive the second sealing rubber cylinder to expand outward. When the hydraulic pressure in the inner cavity of the tubing string reaches a set value, the second sealing rubber cylinder expands outward to seal the annulus.

[0101] Furthermore, a piston ring for abutting against the second sealing rubber cylinder is arranged at the end of the second piston cylinder; a plurality of second sealing rubber cylinders are distributed along the axial direction, and a second spacer ring is arranged between adjacent second sealing rubber cylinders.

[0102] In one embodiment, the open hole packer includes a second adjustment ring, a second center tube, a second upper joint connected to the upper end of the second center tube, and a second lower joint connected to the lower end of the second center tube. The second sealing rubber tube, the second piston cylinder, and the second piston tube are all arranged outside the second center tube. The piston tube is arranged axially. The second adjustment ring is threadedly connected to the outside of the second lower joint and is located below the second sealing rubber tube.

[0103] Specifically, the second upper joint 41, the second central tube 42, and the second lower joint 415 are sequentially connected by threads to form the main body of the tool.

[0104] The upper end of the second center tube 42 is connected to the second upper joint 41 through threads, wherein another set of threads on the outer side of the upper part is connected to the second piston cylinder 43 and sealed by a sealing ring 44. The second piston cylinder 43 and the inner cavity 51 of the pipe column are connected through the flow hole on the second center tube 42. The second piston cylinder 45 is inserted between the second center tube 42 and the second piston cylinder 43, and the two are sealed by a sealing ring; the wedge ring 46 is inserted between the second piston cylinder 43 and the second piston cylinder 45 to play a filling limit role.

[0105] The locking ring 47 is a steel ring made of spring steel with a small opening, and a sawtooth-shaped locking tooth is processed inside to cooperate with the locking tooth on the outside of the second piston cylinder 45, so as to only allow the second piston cylinder 45 to move axially downward, and cannot recover naturally.

[0106] The retaining ring 48 is connected to the second piston cylinder 43 through a threaded connection to ensure that the locking ring 47 will not move with the second piston cylinder 45, playing a limiting role. The outer side of the upper end is processed with threads to connect with the second piston cylinder 43, and the lower end is designed with an installation hole to facilitate the installation of the retaining ring 48.

[0107] The shear screws 49 are installed in a circumferentially uniformly distributed state at the connecting part of the second piston cylinder 43 and the retaining ring 48, penetrating the two and part of the second piston cylinder 45, and playing a limiting role. When the second piston cylinder 45 is not subjected to force or only subjected to a small downward axial force, all parts of the tool remain in their original state; when the downward axial force exerted on the second piston cylinder 45 reaches a certain value, the shear screws 49 are cut off, and the second piston cylinder 45 moves downward.

[0108] The piston ring 410 is connected to the second piston cylinder 45 by a threaded connection, which plays a role in limiting and increasing the force-bearing area. The second adjusting ring 414 is connected to the second lower joint 415 by a threaded connection, and the position of each sleeve component on the second central tube 42 is adjusted by the amount of screwing in and out of the thread between the two, filling the gap and ensuring that each component is tightly installed axially.

[0109] The second sealing rubber cylinder 411, the rubber cylinder shoulder 412, and the spacer ring 413 are installed between the piston ring 410 and the second adjustment ring 414. The spacer ring 413 is sleeved between the two sets of second sealing rubber cylinders 411 to play a role of separation. The rubber cylinder shoulder 412 is generally made of copper or other softer metals to protect the second sealing rubber cylinder 411. The second sealing rubber cylinder 411 is generally made of rubber. According to the use temperature, sealing pressure and other factors, it can be made of nitrile rubber, hydrogenated nitrile rubber, fluororubber, etc., or graphite + nickel wire, etc. The second sealing rubber cylinder 411 can be deformed within a certain range to play a sealing role.

[0110] When the tool is in use, the high-pressure fluid from the inside of the tool enters the second piston cylinder 43, and pushes the second piston tube 45 axially downward. When the axial force reaches a certain value, the shear screw 49 is cut off, and the second piston tube 45 drives the piston ring 410 to move downward, acting on the second sealing rubber tube 411. The second sealing rubber tube 411 is axially compressed, radially expanded, and expanded outward to fill the space between the tool and the wellbore, that is, it plays a sealing role. Under the action of the locking ring 47, the pressure is stopped at this time, and each component still maintains the state before the pressure is stopped, and the sealing continues.

[0111] In one embodiment, the micro-hole drilling tool includes a naked hole stabilizer, which includes a straightening block, a third piston cylinder and a third piston tube. The third piston cylinder is connected to the inner cavity of the pipe string. The third piston tube is installed in the third piston cylinder and can move under the hydraulic action in the third piston cylinder and drive the straightening block to expand radially for straightening and anchoring.

[0112] Furthermore, the open hole centralizer comprises a centralizing cone, the conical surface of the centralizing cone cooperates with the centralizing block, and the third piston cylinder can move axially and drive the centralizing block to expand radially through the centralizing cone.

[0113] The structure and working principle of the open hole straightener are roughly the same as those of the open hole packer. Specifically, the piston ring 410 of the open hole packer is replaced by the straightening cone 425 of the straightener, the second sealing rubber tube 411 is replaced by the straightening block 426, and a slot structure is added to the upper end of the third adjustment ring 427, which also adds the function of cooperating with the installation of the straightening block 426. The straightening block 426 is in a cross-petal shape as a whole, has good radial expansion and contraction functions, and is highly elastic. Its lower end is installed in cooperation with the slot at the upper end of the third adjustment ring 427, and its upper end is installed in cooperation with the straightening cone 425. Figure 8 As shown, the open hole centralizer includes a sixth upper joint 416 , a center pipe 417 , a sealing ring 419 , a wedge ring 421 , a retaining ring 423 and a sixth lower joint 428 .

[0114] When the tool is used, the high-pressure fluid from the inside of the tool enters the third piston cylinder 418, pushing the third piston cylinder 420 axially downward; when the axial force reaches a certain value, the shear pin 424 is sheared off, and the third piston cylinder 420 drives the straightening cone 425 to move downward, and the straightening cone 425 is wedged under the straightening block 426, forcing the straightening block 426 to expand radially and fill the space between the tool and the wellbore, that is, it plays a straightening and anchoring role to a certain extent. Under the action of the locking ring 422, the pressure is stopped at this time, and each component still maintains the state before the pressure is stopped, and continues to straighten and anchor. The tool is mainly used in conjunction with the open hole packer to assist in sealing.

[0115] In one embodiment, the perforating sub includes a nozzle and a bursting disc, the nozzle is connected to the front end of the injection pipe, the bursting disc is fixed in front of the nozzle, and the nozzle can break the bursting disc under the drive of the injection pipe. Further, the perforating sub includes a sealing block and a sealing ring, the sealing block is provided with an upper mounting cavity 291 with an opening facing upward and a lower mounting cavity 292 with an opening facing downward, the perforating hydraulic cylinder is at least partially provided in the upper mounting cavity, the bursting disc and the sealing ring are both installed in the lower mounting cavity, the bursting disc is located below the sealing ring, the injection pipe passes through the sealing ring and is sealed, and the sealing block and the sealing ring can play a role in positioning and guiding. Multiple sealing blocks can be arranged along the circumference, and multiple groups of perforating hydraulic cylinders, perforating pistons, and injection pipes are arranged accordingly.

[0116] The perforating sub includes a first central tube, a perforating hydraulic cylinder and a guide wedge are both arranged outside the first central tube, the perforating hydraulic cylinder is arranged axially, and the guide wedge is provided with a wedge inclined surface 220 for guiding the injection pipe and the nozzle. Figure 3 As shown, the perforating hydraulic cylinder and the injection pipe are both arranged in the axial direction, and are guided by the wedge inclined surface of the guide wedge to be turned to extend in the radial direction.

[0117] Furthermore, the perforating sub includes a first adjusting ring, a first upper joint connected to the upper end of the first center pipe and a first lower joint connected to the lower end of the first center pipe. The first adjusting ring is sleeved on the outside of the first center pipe and screwed to the first lower joint. The first adjusting ring is located below the guide wedge.

[0118] In one embodiment, the perforating sub comprises a guide ring, the guide ring is provided with an axial groove, the guide wedge is installed in the axial groove and is fixedly connected by a positioning pin.

[0119] Specifically, Figure 3 and Fig.14 As shown, the first upper joint 21, the first center tube 23, and the first lower joint 218 are connected by threads to form the tool body. The first upper joint 21 is connected to the flow sleeve 22 by threads, sealed by a sealing ring, and the flow hole on the first upper joint 21 maintains liquid communication.

[0120] The flow sleeve 22 and the first center tube 23 are sealed by a sealing ring. The end surface of the flow sleeve 22 is provided with a plurality of cylinder mounting holes, and the inner surface is threaded. One end of the perforating hydraulic cylinder 24 is mounted on the cylinder mounting hole of the flow sleeve 22 through the thread, and is sealed by a sealing ring 25. The other end is also connected to the sealing block 29 through the thread and is sealed by a sealing ring. Preferably, the flow sleeve 22 is provided with four cylinder mounting holes, and four perforating hydraulic cylinders 24 are installed accordingly.

[0121] A sealing ring is installed on the outside of the perforating piston 27, and the inside is connected to the upper end of the injection pipe 28 through a thread, and is inserted into the perforating hydraulic cylinder 24 together; the lower end of the injection pipe 28 passes through the sealing block 29 and the sealing ring 210 and is connected to the nozzle 211. Sealing rings are installed on both the inner and outer sides of the sealing ring 210, and are installed between the sealing block 29 and the injection pipe 28.

[0122] A bursting disc 212 is installed below the sealing ring 210. When the pressure on one side of the nozzle 211 reaches a certain value, the bursting disc can rupture. A retaining ring 213 is installed below the bursting disc to play a limiting role. The casing 26 is sleeved on the outside of the perforating hydraulic cylinder 24 to play a protective and limiting role.

[0123] The guide ring 214 is sleeved on the first center tube 23, and its upper end is inserted into the gap of the sealing block 29 in a petal shape to form a circumferential limit. An axial groove is processed on the outer side of the middle part of the guide ring 214, and a guide wedge block 215 is installed in the groove and fixedly connected with a positioning pin 216.

[0124] The first adjusting ring 217 is sleeved on the first central tube 23, the upper end is tightly attached to the guide ring 214, and the lower end is connected to the first lower joint 218 by threads. The axial position of the first adjusting ring 217 is adjusted by how much the threads are screwed in and out to ensure that the axial parts are tightly installed. After installation, the first lower joint 218 and the first adjusting ring 217, the first adjusting ring 217 and the guide ring 214, the first upper joint 21 and the flow sleeve 22, and the flow sleeve 22 and the sealing block 29 are fixedly connected by spot welding.

[0125] When the tool is in use, high-pressure liquid enters the flow sleeve 22 from the first upper joint 21, and flows through the perforating hydraulic cylinder 24, the perforating piston 27, the injection pipe 28, and the nozzle 211 in sequence, and uses the pressure drop generated by flowing through each component to push the perforating piston 27 forward; at the same time, the high-pressure liquid flows through the nozzle 211 to form a high-pressure jet. Under the action of the high-pressure jet and axial force, the nozzle 211 and the injection pipe 28 break through the bursting disc 212, and under the action of the guide wedge 215, the forward path of the jet is changed, and finally radial jet drilling is formed.

[0126] In order to achieve the purpose of effective rock breaking, acid can be used as the working fluid for carbonate rock and other formations, and the rock can be broken by the dual effects of hydraulic power and acid etching; for sandstone and other formations, a power unit (such as a turbine, etc.) can be set inside the tool, and the power unit can be driven by pumping fluid from the ground to drive the drilling pipe (jet pipe 28) and the front cutting drill bit (nozzle) to rotate and drill to break the rock. In addition, abrasives can be added to the drilling fluid to assist in improving the rock breaking efficiency.

[0127] In one embodiment, if Figure 4 As shown, the oil drain pipe includes a main body, and the pipe wall of the main body is provided with a leakage hole; the connecting structure includes a valve seat, a plugging ball and a first supporting spring, the valve seat is installed on the leakage hole, the first supporting spring can drive the plugging ball to abut against the valve seat to form a leakage hole on the pipe wall, and the plugging ball can overcome the elastic force of the first supporting spring and leave the valve seat to open the leakage hole under the hydraulic pressure in the annulus. When the pressure in the annulus is greater than the pressure in the inner cavity of the pipe column, the plugging ball is pressed inward to compress the first supporting spring 33, and the fluid in the annulus can enter the inner cavity of the pipe column through the gap between the valve seat 34 and the plugging ball 36.

[0128] Specifically, Figure 4 and Fig.15 As shown, a number of leakage holes are evenly distributed on the main body 31. The leakage holes are large on the outside and small on the inside. The valve core 32, the first supporting spring 33, the blocking ball 36, and finally the valve seat 34 are installed in the holes in sequence. The valve seat 34 is connected to the main body 31 through threads and sealed by a sealing ring 35.

[0129] When there is no external force, under the action of the first supporting spring 33, the valve core 32 is close to the limiting step on the main body 31, and the blocking ball 36 is close to the valve seat 34, playing a sealing role; when the external pressure of the tool is greater than the internal pressure, the blocking ball 36 is pressed inward to compress the first supporting spring 33, and the external fluid can enter the interior of the tool through the gap between the valve seat 34 and the blocking ball 36.

[0130] In another embodiment, Figure 5 As shown, the oil drain pipe includes a third upper joint, a positioning joint, an oil drain nipple and a third lower joint which are connected in sequence, the oil drain nipple is provided with an external oil leakage groove 391, and the inner wall of the positioning joint is provided with a first limiting groove 381; the connecting structure includes a movable inner cylinder 300, the movable inner cylinder 300 is arranged in the positioning joint, the outer wall of the movable inner cylinder is provided with a positioning protrusion 3131, the inner wall of the movable inner cylinder is provided with a first internal step portion 3142, the movable inner cylinder is provided with an internal oil leakage groove, the movable inner cylinder can move downward when the first internal step portion 3142 is subjected to a downward thrust, and move until the internal oil leakage groove 3141 is aligned with the external oil leakage groove 391, and at the same time the positioning protrusion 3131 is stuck in the first limiting groove 381.

[0131] The external tool can apply a downward thrust to the movable inner cylinder through the first internal step portion 3142, so that the movable inner cylinder moves until the inner leakage oil groove is aligned with the outer leakage oil groove, and locks the movable inner cylinder through the snap fit of the positioning protrusion 3131 and the first limiting groove 381, and the fluid in the annulus enters the inner cavity of the tubing string through the outer leakage oil groove 391 and the inner leakage oil groove 3141.

[0132] Furthermore, the movable inner cylinder includes a locking retaining spring and an inner cylinder body distributed from top to bottom, the positioning protrusion is arranged on the locking retaining spring, and the first internal step portion 3142 and the internal oil leakage groove are both arranged on the inner cylinder body; the oil leakage pipe includes a first protective sleeve arranged on the inner side of the positioning joint, the first protective sleeve is fixedly connected to the third upper joint, the locking retaining spring is arranged between the first protective sleeve and the positioning joint, and the first protective sleeve can make the locking retaining spring and the inner cylinder body move more smoothly.

[0133] like Figure 5 As shown, the inner wall of the inner cylinder body is provided with a lower limit groove 3143 located below the inner oil leakage groove, and the first inner step portion 3142 is formed at the lower boundary of the lower limit groove 3143.

[0134] Furthermore, the inner wall of the inner cylinder body is provided with a middle limit groove 3145 located above the inner oil leakage groove, and the upper boundary of the middle limit groove 3145 forms a second inner step portion 3144. An external tool can lift the movable inner cylinder through the second inner step portion to stagger the inner oil leakage groove with the outer oil leakage groove, thereby closing the oil leakage.

[0135] In one embodiment, the micro-hole drilling tool includes a sleeve switching tool, such as Figure 6 As shown, the sleeve switch tool includes a sleeve central axis, a switch block and a second supporting spring. The switch block is installed on the sleeve central axis and can move radially. The second supporting spring is connected to the switch block to drive the switch block to have a tendency to move radially outward. The switch block can be inserted into the lower limit groove 3143. The sleeve switch tool applies a downward thrust to the movable inner cylinder through the switch block and the first internal step portion.

[0136] Specifically, Figure 5 , Fig.16 and Fig.17 As shown, the third upper joint 37, the positioning joint 38, the oil drain nipple 39, and the third lower joint 310 are connected in sequence by threads, and the sealing ring 312 is used to ensure the sealing, so as to form the tool body. A plurality of external oil drain grooves are evenly distributed in the circumferential direction in the middle of the oil drain nipple 39. The inner side of the middle of the third upper joint 37 is connected to the first casing 311 by threads. The locking claw spring 313 and the inner tube body 314 are connected by threads, and the two are sleeved between the first casing 311 and the tool body.

[0137] The middle part of the locking claw spring 313 is hollowed out in a split-petal state, and a positioning protrusion is provided on the outer side of each rib plate. This part has good elasticity.

[0138] Two limit grooves are designed on the inner side of the upper and middle parts of the positioning joint 38, and screw holes are processed in the middle and lower parts to install the limit screws 315. The inner cylinder body 314 is designed with threads, upper limit grooves, middle limit grooves, inner leakage oil grooves, and lower limit grooves from top to bottom. The threads are used to connect the locking claw spring 313; the upper limit groove is designed on the outer side of the inner cylinder body 314, axially, and cooperates with the limit screws 315 to prevent the inner cylinder body 314 and the tool body from rotating relative to each other; the inner leakage oil groove and the outer leakage oil groove are basically the same in shape and size, and in the same direction; the middle limit groove and the lower limit groove are located on the inner side of the inner cylinder body 314, in an annular shape, and cooperate with the sliding sleeve switch tool to realize the sliding sleeve switch.

[0139] like Figure 6 As shown, the fourth upper joint 316, the central axis of the sleeve 317, and the fourth lower joint 321 are connected by threads and sealed by a sealing ring 318 to form a tool body. The fourth upper joint 316 and the fourth lower joint 321 are designed with limited steps, and the central axis of the sleeve 317 and the switch block 319 are designed with mounting grooves. The second support spring 320 is installed between the two mounting grooves to support the switch block 319. The switch block 319 is installed in the mounting groove on the central axis of the sleeve 317, and the upper and lower ends are limited by the limited steps on the upper and lower sides. Under the action of the upper and fourth lower joints 321, the central axis of the sleeve 317, and the second support spring 320, the switch block 319 can move radially within a certain range.

[0140] The switchable sleeve and the sleeve switch tool are used in combination. In the initial state, the positioning protrusion on the outer side of the rib plate of the locking claw spring 313 is located above the first limit groove of the positioning joint 38. At this time, the inner leakage oil groove on the inner tube body 314 and the outer leakage oil groove on the oil leakage short section 39 are in a misaligned state, and the inside and outside of the tool are isolated and not connected.

[0141] After the sleeve switch tool is lowered, the switch block 319 on the sleeve switch tool is in a compressed state. After the sleeve switch tool is lowered to the two limit grooves on the inner side of the sleeve inner tube body 314, the switch block 319 is repeatedly compressed and expanded under the action of the steps inside the limit grooves, and at the same time, a large axial thrust is given to the inner tube body 314, driving the locking claw spring 313 to move axially together. At this time, the positioning protrusion on the outer side of the rib plate of the locking claw spring 313 is compressed and contracted, and after moving to the first limit groove in the middle of the positioning joint 38, the positioning protrusion expands and is stuck in the first limit groove, and the inner and outer oil drain grooves are aligned to achieve internal and external communication.

[0142] The repeated compression-expansion of the switch block 319 is manifested as the suspended weight decreasing-increasing-decreasing-increasing on the ground weight indicator. Under the action of the external step of the switch block 319 and the internal step of the limiting groove of the inner tube body 314, when the suspended weight increases to the normal value for the second time, it indicates that the sliding sleeve is open.

[0143] When the sleeve needs to be closed, the sleeve switch tool is inverted and lowered into the pipe column. When the suspended weight rises and falls several times and returns to normal, it means that the sleeve switch tool has passed through the sleeve. At this time, the sleeve switch tool is lifted up, and it also has to go through several suspended weight rises and falls. When the suspended weight returns to normal, it means that the sleeve is closed. At this time, the small protrusion on the outside of the rib plate of the locking claw spring 313 returns to the limit groove on the upper part of the positioning joint 38, and the inner and outer leakage oil grooves are staggered, and the inside and outside are isolated.

[0144] Figure 4 The oil drain pipe shown has the following characteristics: it does not need to be opened specially. When the external pressure is greater than the internal pressure, the oil drain channel automatically opens and the external fluid enters the tool; when the external pressure is less than the internal pressure, the oil drain channel closes. The disadvantage is that it is difficult to manually control the channel switch.

[0145] Figure 5 The drain pipe shown has the following characteristics: It requires a special Figure 6 The sliding sleeve switch tool shown in the figure realizes the opening and closing of the oil drain channel. It is slightly complicated, but has strong controllability and the flow channel is smoother. You can choose to use it according to actual needs. Figure 5 Drain pipe as shown or Figure 4 Drain pipe shown.

[0146] In one embodiment, the hanging packer includes a fifth upper joint 61, a locking shaft, a first hydraulic cylinder 62, a first piston cylinder and a ball seat, and the ball seat is connected to the inner side of the fifth upper joint 61 through a first shear pin; the locking shaft is sleeved outside the fifth upper joint 61, and the first sealing rubber tube is sleeved outside the locking shaft; the first hydraulic cylinder and the first piston cylinder are sleeved outside the fifth upper joint 61 and are located above the first sealing rubber tube; the fifth upper joint 61 is provided with a first hydraulic through hole 60 connecting the inner cavity of the tubing string with the first hydraulic cylinder; the ball seat blocks the first hydraulic through hole 60 and can deviate from the first hydraulic through hole 60 under the action of throwing a ball.

[0147] The ball falls onto the ball seat, cutting off the first shear pin. After the ball seat moves, the first hydraulic through hole 60 opens. The high-pressure liquid in the inner cavity of the pipe column flows into the first hydraulic cylinder through the first hydraulic through hole 60, driving the first piston cylinder to move, thereby driving the first sealing rubber cylinder to expand.

[0148] Furthermore, the cava mechanism includes a cava and a cava wedge ring sleeved outside the locking shaft. The cava wedge ring is arranged below the first sealing rubber cylinder and cooperates with the cava through an inclined surface. When the first piston cylinder moves downward, the cava wedge ring is also pushed through the first sealing rubber cylinder and driven to move radially outward under the action of the inclined surface.

[0149] Specifically, Fig. 9 As shown, the upper end of the fifth upper joint 61 is designed with threads inside for connecting the upper tool, and the outer side is designed with threads and steps for connecting the first hydraulic cylinder 62. The two are connected by threads and sealed by a sealing ring 64. The first fixing screw 63 is used to prevent loosening, and the axial installation position is limited by a limiting step. The outer wall of the fifth upper joint 61 is designed with a first hydraulic through hole 60 to achieve internal and external communication.

[0150] The ball seat 65 is inserted into the inner side of the fifth upper joint 61, and a first shear pin 67 and a limit step are designed between the two to define the axial position, and a sealing ring is used to form a seal. The upper end of the ball seat 65 is in a trumpet shape for receiving a sealing ball, and a threaded mounting retaining ring 620 is designed on the outer side of the lower end, and a third fixing screw 621 is installed between the two to prevent loosening, and a support ring 619 is installed between the limit step above the thread on the outer side of the lower end of the ball seat 65 and the retaining ring 620. The ring is conical in shape, and cooperates with the locking claw spring 601 at the lower end of the fifth upper joint 61 to play a supporting role.

[0151] Fig.11 and Fig.11A FIG. 2 shows a structural diagram of an embodiment of a slip seat. Fig. 9 , Fig.10 and Fig. 10AAs shown, the locking claw spring 601 at the lower end of the fifth upper joint 61 is in a petal shape, with good radial expansion and compression performance. The inner side of the lower end of the locking claw spring 601 is in a trumpet shape, which cooperates with the support ring 619, and the outer side is in an outward convex shape, which cooperates with the slip seat limiting groove 6171 inside the slip seat 617, and is stuck in the slip seat limiting groove 6171. A limiting structure is formed between the support ring 619, the locking claw spring 601, and the slip seat limiting groove 6171. The first piston cylinder 66 is inserted between the first hydraulic cylinder 62 and the fifth upper joint 61, and is sealed between the two by a sealing ring. A second shear pin 68 is installed between the first hydraulic cylinder 62 for fixed limiting.

[0152] The locking shaft 611 is sleeved on the outer side of the lower middle part of the fifth upper joint 61, and its lower part is designed with threads to connect with the slip seat 617, and is locked by the second fixing screw 618; and the outer side of its upper end is designed with serrated locking teeth.

[0153] The locking sleeve 69, the locking ring 610, the shoulder 612, the first sealing rubber cylinder 613, the spacer ring 614, the slip wedge ring 615, and the slip 616 are all sleeved on the locking shaft 611. The upper part of the locking sleeve 69 is connected to the first piston cylinder 66 by threads, and the locking ring 610 is installed in the cavity between the locking sleeve 69 and the first piston cylinder 66. It has the same structure as the locking ring 47 of the open hole packer, and both are open rings. The inner side is designed with locking teeth, which cooperate with the locking teeth at the upper end of the locking shaft 611 to play a role in stopping retreat.

[0154] The shoulder guard 612, the first sealing rubber tube 613, the shoulder guard 612, the spacer ring 614, the shoulder guard 612, the first sealing rubber tube 613, the shoulder guard 612, the slip wedge ring 615 and the slip 616 are installed in sequence below the locking sleeve 69. The structure of the shoulder guard 612, the first sealing rubber tube 613 and the spacer ring 614 is roughly the same as that of the open hole packer.

[0155] The slip wedge ring 615 is annular, with 3-4 wedge grooves evenly distributed on the outside, and a limit step designed on the inside, which cooperates with the limit step on the locking shaft 611, so that the slip wedge ring 615 can only move downward, not upward. The slip teeth are designed on the outside of the slip 616, which have both wedge-shaped and dovetail-shaped assembly structures, and are installed in the slip seat 617 and the wedge groove.

[0156] When the tool is in use, a ball is thrown into the tool, and the sealing ball falls on the ball seat 65 to seal the middle passage. At this time, high-pressure fluid is injected to hold the pressure. When the pressure reaches a certain value, the first shear pin 67 is cut off; the ball seat 65 moves downward, exposing the first hydraulic through hole 60 on the outer wall of the fifth upper joint 61, and the high-pressure fluid enters the first hydraulic cylinder 62 through the first hydraulic through hole 60, pushing the first piston cylinder 66 to cut off the second shear pin 68 and move downward; pushing the first sealing rubber cylinder 613 to radially expand the sealing annulus; at the same time, the cava wedge ring 615 moves downward to make the cava 616 radially expand to achieve suspension anchoring; at the same time, the support ring 619 moves downward with the ball seat 65, and the locking claw spring at the lower end of the fifth upper joint 61 cannot support it. At this time, the pipe column is lifted, the locking claw spring contracts, and the fifth upper joint 61 carrying the first hydraulic cylinder 62, the ball seat 65, the sealing ball and other components can be lifted out of the wellbore, and other components remain underground to maintain the suspended sealing state.

[0157] like Figure 1 As shown, the micro-hole drilling tool includes a guide shoe 1, a perforating nipple 2, an oil drain pipe 3, an open hole packer 4, a casing 5 and a liner suspension packer 6.

[0158] In one embodiment, if Figure 2 As shown, the guide shoe includes a seventh upper joint 11, a seventh lower joint 13, a guide shoe central axis 15, and a guide shoe body 14. The seventh upper joint 11 and the seventh lower joint 13 are connected by threads, and communication holes are respectively designed on both sides of the connection section. The intermediate sleeve 12 is sleeved on the outside and sealed by an O-ring. The upper thread of the seventh upper joint 11 is used to connect the upper tool, and the lower part of the seventh lower joint 13 is connected to the guide shoe body 14 by threads. The bottom of the guide shoe body 14 is designed with a communication hole for realizing the communication of the medium inside and outside the tool.

[0159] The guide shoe center shaft 15 is in the shape of a solid piston, with a sealing mechanism designed on the upper part, a sealing ring assembly installed, and a limit ring is used to fix the limit. A connecting hole is designed in the middle of the guide shoe center shaft 15, and during initial installation, the connecting hole is aligned with the connecting hole on the seventh upper joint 11. The guide shoe center shaft 15 and the seventh upper joint 11 are fixed by a shear pin 18.

[0160] In the initial state, the connecting holes on the guide shoe center axis 15 and the seventh upper joint 11 are aligned, and the inner cavity of the tubular column - the connecting hole of the guide shoe center axis 15 - the connecting hole of the seventh upper joint 11 - the annulus between the seventh upper joint 11 and the intermediate sleeve 12 - the connecting hole of the seventh lower joint 13 - the guide shoe channel 141 of the guide shoe body 14 are connected in sequence, allowing entry and exit to be cut off.

[0161] When the ball is dropped above the tool, it falls into the conical sealing seat above the central axis 15 of the guide shoe, pressurizes it, and the shear pin 18 is cut off, the central axis 15 of the guide shoe moves downward, and the communication path is closed.

[0162] The guide shoe plays a guiding role in the entire process of lowering the micro-hole drilling tool string, and can establish circulation as needed; when the entire string is lowered to the predetermined well depth, the circulation can be blocked by throwing a ball or other means to establish a closed space inside the entire string.

[0163] When the micro-hole drilling tool provided by the present invention is used on site, the specific operation steps include:

[0164] 1. According to the wellbore trajectory and reservoir characteristics, comprehensively determine the location where construction and transformation are required to achieve accurate reservoir transformation and ensure the smooth progress of construction;

[0165] 2. The assembled drilling tool string is lowered into the predetermined position in the well through the drill pipe. The combination of the drilling tool string from bottom to top is: guide shoe + casing + open hole packer + casing + perforating nipple + casing + drain pipe + open hole packer + ... + tail pipe hanging packer. In the combination, the position and quantity of the open hole packer (including the open hole centralizer), perforating nipple, drain pipe and the length of the casing are determined by the optimization design of the wellbore structure, construction parameters, etc.;

[0166] The entire completion string is suspended and fixed on the upper casing through the tail pipe hanging packer and the annulus is sealed, and the drill pipe is pulled out after the packer is released;

[0167] 3. Connect the working pipe string, then drop the ball to pressurize it, close the internal and external connecting channels on the guide shoe, and make the entire pipe string a closed space;

[0168] Increase the pumping pressure to exceed the activation pressure of the open hole packer, so that it can be set and the reservoir can be separated into several sections;

[0169] 4. The pressure continues to increase and exceeds the activation pressure of the perforating sub. The jet pipe 28 and the nozzle 211 begin to extend outward and break the rock, forming a plurality of micropores with high conductivity in each section of the reservoir.

[0170] After the construction is completed, the injection pipe 28 remains in the micro-hole to support the well wall;

[0171] 5. Lower the sleeve switch tool, open the drain pipe, and allow formation fluid to flow from outside the tubing string into the tubing string, thereby carrying out oil and gas production operations.

[0172] 6. Connect the production string back to start production. The formation fluid enters the annulus between the drilling string and the main wellbore from the annulus between the micropores and the injection pipe 28, and enters the completion string through the oil drain pipe, and is then produced to the surface.

[0173] 7. After a period of production, when a certain section of the well is water-invaded and produces water prematurely, a sliding sleeve switch tool can be lowered to close the oil drain pipe of that section of the well to prevent further deterioration and cause the entire well to be flooded, affecting oil and gas production.

[0174] After the construction is completed, the perforating sub can form multiple micro-holes in the radial direction, and the length of a single hole can reach more than 10m, which can effectively penetrate the contaminated zone 73 formed during the drilling process around the main wellbore 74. Fig.12 and Fig.13 As shown, radial channels 71 are formed, and natural fractures 72 in the formation can be communicated at the same time, which greatly expands the oil leakage area of ​​the main wellbore, thereby achieving increased production.

[0175] In this micro-hole drilling tool, multiple perforating subs can be arranged axially; one perforating sub can be circumferentially arranged with multiple perforating hydraulic cylinders and corresponding perforating pistons, jet pipes and guide wedges, so that simultaneous multi-shot high-efficiency micro-hole drilling can be carried out. This micro-hole drilling tool can quickly, specifically and controllably transform the reservoir, and can selectively and quickly arrange up to hundreds of tiny channels in the reservoir at the same time according to the needs. It has a long penetration distance and no compaction effect, so as to achieve the purpose of removing near-well pollution, increasing the contact area of ​​the reservoir, achieving vertical connection, and communicating the natural fractures of the reservoir, thereby increasing the single well production and recovery rate. It has the advantages of controllable reservoir transformation position, direction, and range, simple operation, small amount of liquid, high safety, short operation cycle, and low cost. At the same time, it also has the functions of sand prevention and oil and gas channel closure, which can improve the production effect in sand-prone formations such as heavy oil and water-invaded wells.

[0176] The above are only several embodiments of the present invention. Those skilled in the art may make various changes or modifications to the embodiments of the present invention based on the contents disclosed in the application documents without departing from the spirit and scope of the present invention.

Claims

1. A micro-hole drilling tool, characterized in that: include: A suspension packer, a drain pipe, a perforating nipple and a guide shoe, wherein the suspension packer comprises a first sealing rubber tube and a slip mechanism, wherein the first sealing rubber tube and the slip mechanism can radially expand under the action of ball throwing and pressure to seal the annulus and suspend the anchor respectively; the guide shoe is provided with a guide shoe channel connected to the annulus, and the guide shoe can close the guide shoe channel under the action of ball throwing and pressure; the drain pipe is provided with a connecting structure for connecting the annulus with the inner cavity of the tubing string; The perforating sub includes a perforating hydraulic cylinder, a perforating piston, an injection pipe and a guide wedge. The perforating hydraulic cylinder is communicated with the inner cavity of the pipe string. The injection pipe is connected to the perforating piston. The perforating piston is installed in the perforating hydraulic cylinder and can drive the injection pipe to move under the hydraulic action in the perforating hydraulic cylinder. The injection pipe can be radially extended under the guiding action of the guide wedge; and the injection pipe is communicated with the perforating hydraulic cylinder.

2. The micro-hole drilling tool according to claim 1, characterized in that: The micro-hole drilling tool includes an open hole packer, which includes a second sealing rubber cylinder, a second piston cylinder and a second piston cylinder. The second piston cylinder is connected to the inner cavity of the pipe column. The second piston cylinder is installed in the second piston cylinder and can move under the hydraulic action in the second piston cylinder and drive the second sealing rubber cylinder to expand outward.

3. The micro-hole drilling tool according to claim 2, characterized in that: The end of the second piston cylinder is provided with a piston ring for abutting against the second sealing rubber cylinder; a plurality of the second sealing rubber cylinders are distributed along the axial direction, and a second spacer ring is provided between adjacent second sealing rubber cylinders.

4. The micro-hole drilling tool according to claim 2, characterized in that: The open hole packer includes a second adjustment ring, a second center tube, a second upper joint connected to the upper end of the second center tube, and a second lower joint connected to the lower end of the second center tube. The second sealing rubber tube, the second piston cylinder and the second piston tube are all arranged outside the second center tube. The piston tube is arranged axially. The second adjustment ring is threadedly connected to the outside of the second lower joint and is located below the second sealing rubber tube.

5. The micro-hole drilling tool according to claim 1, characterized in that: The micro-hole drilling tool includes an open hole centralizer, which includes a centralizing block, a third piston cylinder and a third piston barrel. The third piston cylinder is connected to the inner cavity of the pipe string. The third piston barrel is installed in the third piston cylinder and can move under the hydraulic action in the third piston cylinder and drive the centralizing block to expand radially.

6. The micro-hole drilling tool according to claim 5, characterized in that: The open hole centralizer comprises a centralizing cone, the conical surface of which cooperates with the centralizing block, and the third piston cylinder can move axially and drive the centralizing block to expand radially through the centralizing cone.

7. The micro-hole drilling tool according to claim 1, characterized in that: The perforating sub includes a nozzle and a bursting piece. The nozzle is connected to the front end of the injection pipe. The bursting piece is fixed in front of the nozzle. The nozzle can break through the bursting piece under the drive of the injection pipe.

8. The micro-hole drilling tool according to claim 7, characterized in that: The perforating nipple comprises a sealing block and a sealing ring. The sealing block is provided with an upper mounting cavity with an opening facing upward and a lower mounting cavity with an opening facing downward. The perforating hydraulic cylinder is at least partially arranged in the upper mounting cavity. The bursting disc and the sealing ring are both installed in the lower mounting cavity. The bursting disc is located below the sealing ring. The injection pipe passes through the sealing ring and is sealed.

9. The micro-hole drilling tool according to claim 7, characterized in that: The perforating sub includes a first central tube, the perforating hydraulic cylinder and the guide wedge are both arranged outside the first central tube, the perforating hydraulic cylinder is arranged axially, and the guide wedge is provided with a wedge slope for guiding the injection pipe and the nozzle.

10. The micro-hole drilling tool according to claim 9, characterized in that: The perforating sub includes a first adjusting ring, a first upper joint connected to the upper end of the first center pipe, and a first lower joint connected to the lower end of the first center pipe. The first adjusting ring is sleeved on the outside of the first center pipe and screwed to the first lower joint. The first adjusting ring is located below the guide wedge.

11. The micro-hole drilling tool according to claim 10, characterized in that: The perforating sub comprises a guide ring, the guide ring is provided with an axial groove, the guide wedge is installed in the axial groove and is fixedly connected by a positioning pin.

12. The micro-hole drilling tool according to claim 1, characterized in that: The oil drain pipe comprises a main body, and a drain hole is arranged on the pipe wall of the main body; The connecting structure includes a valve seat, a blocking ball and a first supporting spring. The valve seat is installed on the leakage hole. The first supporting spring can drive the blocking ball to abut against the valve seat to close the leakage hole through the pipe wall. Moreover, the blocking ball can overcome the elastic force of the first supporting spring and leave the valve seat to open the leakage hole under the hydraulic action in the annulus.

13. The micro-hole drilling tool according to claim 1, characterized in that: The oil drain pipe comprises a third upper joint, a positioning joint, an oil drain nipple and a third lower joint which are connected in sequence, the oil drain nipple is provided with an external oil drain groove, and the inner wall of the positioning joint is provided with a first limiting groove; The connecting structure includes a movable inner cylinder, which is arranged in the positioning joint, a positioning protrusion is arranged on the outer wall of the movable inner cylinder, a first internal step is arranged on the inner wall of the movable inner cylinder, and an internal leakage oil groove is arranged on the movable inner cylinder. The movable inner cylinder can move downward when the first internal step is subjected to a downward thrust, and move until the internal leakage oil groove is aligned with the external leakage oil groove, and at the same time, the positioning protrusion is stuck in the first limiting groove.

14. The micro-hole drilling tool according to claim 13, characterized in that: The movable inner cylinder comprises a locking circlip and an inner cylinder body which are distributed from top to bottom, the positioning protrusion is arranged on the locking circlip, and the first inner step portion and the inner oil leakage groove are both arranged on the inner cylinder body; The oil drain pipe comprises a first casing disposed inside the positioning joint, the first casing sleeve is fixedly connected to the third upper joint, and the locking clip is disposed between the first casing and the positioning joint.

15. The micro-hole drilling tool according to claim 13, characterized in that: The inner wall of the inner cylinder body is provided with a lower limiting groove located below the inner oil leakage groove, and the first inner step portion is formed at the lower boundary of the lower limiting groove.

16. The micro-hole drilling tool according to claim 15, characterized in that: The inner wall of the inner cylinder body is provided with a middle limiting groove located above the inner oil leakage groove, and the upper boundary of the middle limiting groove forms a second inner step portion.

17. The micro-hole drilling tool according to claim 15 or 16, characterized in that: The micro-hole drilling tool includes a sleeve switch tool, which includes a sleeve center axis, a switch block and a second support spring. The switch block is installed on the sleeve center axis and can move radially. The second support spring is connected to the switch block to drive the switch block to have a tendency to move radially outward, and the switch block can be stuck in the lower limit groove.

18. The micro-hole drilling tool according to claim 1, characterized in that: The suspension packer comprises a fifth upper joint, a locking shaft, a first hydraulic cylinder, a first piston cylinder and a ball seat, wherein the ball seat is connected to the inner side of the fifth upper joint through a first shear pin; The locking shaft sleeve is arranged outside the fifth upper joint, and the first sealing rubber sleeve is arranged outside the locking shaft; The first hydraulic cylinder and the first piston cylinder are sleeved outside the fifth upper joint and are located above the first sealing rubber cylinder; The fifth upper joint is provided with a first hydraulic through hole connecting the inner cavity of the pipe column and the first hydraulic cylinder; the ball seat blocks the first hydraulic through hole and can deviate from the first hydraulic through hole under the action of throwing a ball.

19. The micro-hole drilling tool according to claim 18, characterized in that: The slip mechanism includes a slip and a slip wedge ring sleeved outside the locking shaft. The slip wedge ring is arranged below the first sealing rubber cylinder and cooperates with the slip through an inclined surface.

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