Mechanical shock and water jet combined grooving stress unloading well drilling device and well drilling method

Abstract

The invention discloses a mechanical impact and water jet combined grooving stress unloading drilling device and method, and belongs to the technical field of petroleum drilling engineering. The mechanical impact and water jet combined grooving stress unloading drilling device comprises a pressurization mechanism, an impact mechanism and a drill bit; the impact mechanism comprises an upper connector, a protective cylinder and a lower connector, an impact hammer is matched with the middle of the upper connector, a transmission mandrel is matched with the middle of the lower connector, the drill bit comprises a matrix, a grooving outer cylinder is coaxially and fixedly arranged at the bottom end of the radial outer side of the matrix, PDC teeth are arranged on the matrix, and a plurality of impregnated diamonds are arranged on the grooving outer cylinder in the circumferential direction. When the drill bit reaches the well bottom, the impregnated diamonds make contact with the well bottom earlier than the PDC teeth; a conventional nozzle is arranged at the bottom end of the conventional runner; the high-pressure hose penetrates through the upper connector, the protective cylinder inner cavity, the transmission mandrel, the parent body and the grooving outer cylinder and then is provided with a high-pressure nozzle. According to the invention, shaft bottom rock stress unloading, mechanical impact and ultrahigh pressure water jet combined rock breaking can be realized through the annular cutting groove of the shaft bottom rock, so that the drilling rate is greatly improved.

Description

Technical Field

[0001] The invention belongs to the technical field of petroleum drilling engineering, and in particular relates to a mechanical impact and water jet combined grooving stress unloading drilling device and a drilling method. Background Art

[0002] In the process of oil and gas field development, drilling is a key link. As the depth of the well increases, the bedrock action area is subjected to the coupling effect of strong geostatic stress and hydrostatic pressure, which makes the rock more plastic and harder. The strengthening effect of the bottom rock caused by this stress increases the drilling cycle and drilling cost. In addition, the abrasiveness and natural heterogeneity of the rock matrix greatly reduce the drilling rate. Existing technologies usually increase rock breaking efficiency and improve drilling rate through single mechanical impact or ultra-high pressure jet, but the rock breaking efficiency of each of them is limited by physical conditions, and it is difficult to achieve the best rock breaking effect.

[0003] Therefore, how to reduce the compression effect of the bottom hole rock under the coupling effect of ground stress and hydrostatic column pressure, reduce the difficulty of rock crushing, and thus increase the mechanical drilling speed is the current research direction of drilling technology.

[0004] Based on this, the present application proposes a drilling device and a drilling method for stress unloading by combined mechanical impact and water jet grooving, which realizes annular grooving of the bottom hole rock to unload the bottom hole rock stress, and combined rock breaking by mechanical impact and ultra-high pressure water jet, thereby greatly improving the drilling rate. Summary of the invention

[0005] The purpose of the present invention is to overcome the above-mentioned deficiencies of the prior art and to provide a drilling device for mechanical impact and water jet combined grooving stress unloading.

[0006] To achieve the above object, the present invention adopts the following technical solution: A mechanical impact and water jet combined grooving stress unloading drilling device comprises a booster mechanism, an impact mechanism, and a drill bit which are sequentially connected from top to bottom along the axial direction; The boost mechanism is provided with a first normal pressure channel and a first boost channel, and the lower end of the first boost channel is connected to a high pressure hose; The impact mechanism comprises an upper joint, a casing, and a lower joint which are coaxially fixedly connected in sequence, the upper end of the upper joint is fixedly connected to the lower end of the booster mechanism, a second normal pressure flow channel which runs axially through is arranged on the upper joint, an impact hammer is axially slidably matched in the middle of the upper joint, a disc spring is arranged between the step end face of the outer wall of the impact hammer and the step end face of the inner wall of the upper joint, a transmission core shaft is axially sealed and slidably matched in the middle of the lower joint, and a second through hole which is used to connect the inner cavity of the casing and the inner cavity of the transmission core shaft is arranged at the upper end of the transmission core shaft; the bottom end of the impact hammer and the upper end of the transmission core shaft are located in the inner cavity of the casing to realize the transmission of the impact; The drill bit comprises a mother body coaxially fixedly connected with a driving mandrel, a grooved outer cylinder is coaxially fixedly arranged at the radially outer bottom end of the mother body, a PDC tooth is arranged on the mother body, and a plurality of impregnated diamonds are evenly arranged on the grooved outer cylinder along the circumferential direction; when the drill bit reaches the bottom of the well, the impregnated diamonds contact the bottom of the well before the PDC teeth; The mother body is provided with a conventional flow channel which passes through the bottom end and is in communication with the inner cavity of the transmission core shaft, and a conventional nozzle is provided at the bottom end of the conventional flow channel; The high-pressure hose is provided with a high-pressure nozzle after passing through the upper joint, the inner cavity of the casing, the driving core shaft, the mother body and the grooved outer cylinder.

[0007] Preferably, the boost mechanism comprises an outer cylinder, wherein the outer cylinder comprises a rotating transmission shaft, a conversion joint, a power conversion cylinder, a filter cylinder, a plunger, and a sleeve from top to bottom; The rotating transmission shaft is coaxially fixedly connected with the outer cylinder, the conversion joint is coaxially fixedly arranged with the lower end of the rotating transmission shaft, and the lower part of the conversion joint is connected with the power conversion cylinder through a matching structure, and the matching structure converts the rotational motion of the conversion joint into the axial reciprocating motion of the power conversion cylinder; The filter cartridge is fixedly arranged at the bottom end of the power conversion cartridge, the upper part of the plunger is fixedly arranged at the bottom end of the inner cavity of the filter cartridge, the sleeve is coaxially fixedly connected with the outer cylinder, and a plunger hole matching with the plunger is arranged in the middle of the sleeve; a liquid inlet check valve is arranged at the bottom end of the inner cavity of the plunger, a high-pressure sleeve is fixedly arranged at the bottom end of the plunger hole, and a liquid outlet check valve is arranged at the bottom end of the plunger hole; The inner cavities of the rotating transmission shaft, the conversion joint and the power conversion cylinder are connected, an annular cavity is formed between the filter cylinder and the outer cylinder, a sleeve flow channel penetrating along the axial direction is provided on the sleeve, a first flow hole is provided on the power conversion cylinder to connect its inner cavity with the annular cavity, a second flow hole is provided on the filter cylinder to connect its inner cavity with the annular cavity, and the inner cavities of the filter cylinder and the plunger are connected; The interconnected rotating transmission shaft inner cavity, conversion joint inner cavity, power conversion cylinder inner cavity, first flow hole, annular cavity, and sleeve flow channel form a first normal pressure flow channel; the second flow hole, filter cylinder inner cavity, plunger inner cavity, plunger hole, and high-pressure sleeve inner cavity form a first boost flow channel.

[0008] Preferably, the filter cartridge is a cylindrical structure with a sealed top end.

[0009] Preferably, the upper joint below the disc spring is provided with a first through hole for connecting the second normal pressure flow channel and the inner cavity of the upper joint, and a bypass flow channel passing from the inner cavity of the upper joint to the outside, and a bypass nozzle is provided in the bypass flow channel.

[0010] Preferably, a sealing cap is fixedly disposed on the top end of the inner cavity of the upper joint.

[0011] Preferably, a plurality of blades are evenly arranged along the circumferential direction at the bottom end of the matrix, and a plurality of PDC teeth are arranged on each blade.

[0012] Preferably, a plurality of gauge-keeping portions are evenly arranged on the grooved outer cylinder along the circumferential direction, and the gauge-keeping portions include an outer arc-shaped gauge-keeping portion extending axially along the radial outer wall surface of the grooved outer cylinder, an inner arc-shaped gauge-keeping portion extending axially along the radial inner wall surface of the grooved outer cylinder, and a connecting portion connecting the bottom ends of the outer arc-shaped gauge-keeping portion and the bottom ends of the inner arc-shaped gauge-keeping portion; A plurality of impregnated diamonds are evenly arranged on the outer sides of the outer arc-shaped diameter-keeping portion, the inner arc-shaped diameter-keeping portion and the connecting portion along the extending direction of the generatrix.

[0013] Preferably, the radial outer wall surfaces of all the outer arc-shaped diameter-keeping portions are located on the same cylindrical surface, and the radial inner wall surfaces of all the inner arc-shaped diameter-keeping portions are located on the same cylindrical surface.

[0014] Preferably, the radial cross section of the connecting portion is a semicircular ring structure.

[0015] The invention also provides a mechanical impact and water jet combined grooving stress unloading drilling method.

[0016] The mechanical impact and water jet combined grooving stress unloading drilling method is implemented based on the mechanical impact and water jet combined grooving stress unloading drilling device, and the drilling method includes the following steps: Step 1: When the drill bit reaches the bottom of the well, the diamond impregnated at the bottom of the grooved outer tube contacts the bottom of the well before the PDC teeth; Apply drilling pressure and torque, and under the joint action of the drilling fluid pressure in the casing, the bottom hole thrust on the drill bit, and the disc spring, the impact hammer performs a pulse impact on the drill bit, and the booster mechanism boosts the pressure of the drilling fluid, which is then ejected through the first booster flow channel, the high-pressure hose, and the high-pressure nozzle to form a high-pressure jet; Under the combined effects of drilling pressure, torque, pulse impact and high-pressure jet, the diamond-impregnated rock cuts an annular groove on the bottom face of the well to unload the bottom hole pressure. Step 2: The drill bit continues to drill, the depth of the annular groove continues to deepen, and the PDC teeth begin to contact the bottom hole rock inside the annular groove and break it; Step 3: Under the combined action of drilling pressure, torque, pulse impact and high-pressure jet, the diamond-impregnated cutting of the annular groove and the PDC teeth continuously crush the rock inside the annular groove, thereby achieving combined rock breaking; During the process: The drilling fluid is sprayed outward along the first normal pressure flow channel, the sleeve flow channel, the casing cavity, the second through hole, the transmission core shaft cavity, the conventional flow channel, and the conventional nozzle to transport the broken rock cuttings into the annulus.

[0017] The beneficial effects of the present invention are: The present invention realizes annular grooving on the bottom hole rock surface through the combined arrangement of a booster mechanism, an impact mechanism and a drill bit, thereby releasing the local stress of the bottom hole rock and reducing the difficulty of the bottom hole drill bit "eating into" the rock formation during drilling; at the same time, the mechanical impact produced by the impact mechanism can cause the drill bit to produce cracks on the bottom hole rock surface, thereby reducing the threshold pressure for the ultra-high pressure jet to cut into the rock; ultimately, the annular grooving of the bottom hole rock is achieved to unload the bottom hole rock stress, and the mechanical impact and ultra-high pressure water jet are combined to break the rock, thereby greatly improving the drilling rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The drawings in the specification, which constitute a part of the present application, are used to provide further understanding of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute improper limitations on the present application.

[0019] Figure 1 It is a structural schematic diagram of the mechanical impact and water jet combined grooving stress unloading drilling device of the present invention; Figure 2 It is a structural schematic diagram of the drill bit in the present invention; Figure 3 yes Figure 2 AA section view; Figure 4 It is a structural schematic diagram of the diameter-keeping portion in the present invention; in: 11. first normal pressure flow channel; 12. first boost flow channel; 13. high pressure hose; 131. high pressure nozzle; 14. outer cylinder; 15. rotating transmission shaft; 16. conversion joint; 17. power conversion cylinder; 171. first flow hole; 18. filter cylinder; 181. second flow hole; 19. plunger; 191. liquid inlet check valve; 192. high pressure sleeve; 193. liquid outlet check valve; 110. sleeve; 1101. sleeve flow channel; 21. upper joint; 211. second normal pressure flow channel; 212. first through hole; 213. bypass flow channel; 214. bypass nozzle; 215. sealing cap; 22. casing; 23. lower joint; 24. impact hammer; 241. sealing element; 25. disc spring; 26. transmission mandrel; 261. second through hole; 262. anvil cap cover plate; 31. Mother body; 311. Conventional flow channel; 312. Conventional nozzle; 32. Grooved outer cylinder; 33. PDC teeth; 34. Diamond impregnated; 35. Blade; 36. Gauge guard; 361. Outer arc-shaped gauge guard; 362. Inner arc-shaped gauge guard; 363. Connecting part. DETAILED DESCRIPTION

[0020] It should be noted that the following detailed descriptions are illustrative and are intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present application belongs.

[0021] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0022] In the present invention, the directions or positional relationships indicated by terms such as "upper", "lower", "bottom", "top", etc. are based on the directions or positional relationships shown in the accompanying drawings. They are relational words determined only for the convenience of describing the structural relationships of the various parts or elements of the present invention. They do not specifically refer to any part or element in the present invention and cannot be understood as limitations on the present invention.

[0023] In the present invention, terms such as "connected" and "connection" should be understood in a broad sense, indicating that the connection can be fixed, integral or detachable; it can be directly connected or indirectly connected through an intermediate medium. Relevant scientific research or technical personnel in this field can determine the specific meaning of the above terms in the present invention according to specific circumstances, and they should not be understood as limiting the present invention.

[0024] The present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0025] Embodiment 1: like Figure 1 As shown, the mechanical impact and water jet combined grooving stress unloading drilling device comprises a booster mechanism, an impact mechanism, and a drill bit which are sequentially connected from top to bottom along the axial direction; The boost mechanism is provided with a first normal pressure channel 11 and a first boost channel 12, and the lower end of the first boost channel 12 is connected to a high pressure hose 13; The impact mechanism comprises an upper joint 21, a casing 22, and a lower joint 23 which are coaxially fixedly connected in sequence. The upper end of the upper joint 21 is fixedly connected to the lower end of the booster mechanism. The upper joint 21 is provided with a second normal-pressure flow channel 211 which runs axially through. The second normal-pressure flow channel 211 is used to connect the first normal-pressure flow channel 11 and the casing 22 chamber. An impact hammer 24 is axially slidably fitted in the middle of the upper joint 21. A disc spring 25 is provided between the step end face of the outer wall of the impact hammer 24 and the step end face of the inner wall of the upper joint 21. The upper end of the disc spring 25 abuts against and is fixedly connected to the step end face of the inner wall of the upper joint 21, and the lower end of the disc spring 25 abuts against and is fixedly connected to the step surface of the outer wall of the impact hammer 24. A seal 241 is arranged between the outer wall of the impact hammer 24 above the disc spring 25 and the inner wall of the upper joint 21, and a transmission core shaft 26 is axially sealed and slidably matched in the middle of the lower joint 23, wherein the transmission core shaft 26 and the lower joint 23 are axially slidably matched and torque is transmitted through a spline, and a second through hole 261 for connecting the inner cavity of the casing 22 and the inner cavity of the transmission core shaft 26 is arranged at the upper end of the transmission core shaft 26; the bottom end of the impact hammer 24 and the upper end of the transmission core shaft 26 are located in the inner cavity of the casing 22 to realize the transmission of the impact; specifically, an anvil cap cover plate 262 is arranged at the upper end of the transmission core shaft 26 to prevent the transmission core shaft 26 from falling out of the lower joint 23 downward; The drill bit comprises a matrix 31 which is coaxially fixedly connected to the driving mandrel 26, a grooved outer cylinder 32 is coaxially fixedly arranged at the radially outer bottom end of the matrix 31, a PDC tooth 33 is arranged on the matrix 31, and a plurality of impregnated diamonds 34 are evenly arranged on the grooved outer cylinder 32 along the circumferential direction; when the drill bit reaches the bottom of the well, the impregnated diamonds 34 contact the bottom of the well before the PDC tooth 33; The mother body 31 is provided with a conventional flow channel 311 which passes through the bottom end and communicates with the inner cavity of the transmission core shaft 26, and a conventional nozzle 312 is provided at the bottom end of the conventional flow channel 311; The high-pressure hose 13 passes through the upper connector 21 , the inner cavity of the protective tube 22 , the transmission core shaft 26 , the mother body 31 , and the grooved outer tube 32 , and then is provided with a high-pressure nozzle 131 .

[0026] Preferably, the boost mechanism comprises an outer cylinder 14, wherein the outer cylinder 14 contains, from top to bottom, a rotating transmission shaft 15, a conversion joint 16, a power conversion cylinder 17, a filter cylinder 18, a plunger 19, and a sleeve 110; wherein the bottom end of the outer cylinder 14 is coaxially fixedly connected with the top end of the upper joint 21; The rotating transmission shaft 15 is coaxially fixedly connected with the outer cylinder 14, the conversion joint 16 is coaxially fixedly arranged with the lower end of the rotating transmission shaft 15, and the lower part of the conversion joint 16 is connected with the power conversion cylinder 17 through a matching structure, wherein the outer wall of the power conversion cylinder 17 is slidably matched with the inner wall of the outer cylinder 14, and the matching structure converts the rotational motion of the conversion joint 16 into the axial reciprocating motion of the power conversion cylinder 17; wherein the matching structure for converting the rotational motion of the conversion joint 16 into the axial reciprocating motion of the power conversion cylinder 17 is a prior art and will not be described in detail here, for example, a pin is provided on the power conversion cylinder 17, and a cylindrical cam groove matching with the pin is provided on the conversion joint 16 to realize the conversion between the rotational motion and the axial reciprocating motion; The filter cartridge 18 is fixedly arranged at the bottom end of the power conversion cartridge 17, the upper part of the plunger 19 is fixedly arranged at the bottom end of the inner cavity of the filter cartridge 18, the sleeve 110 is coaxially fixedly connected with the outer cylinder 14, and a plunger hole matching with the plunger 19 is arranged in the middle of the sleeve 110; a liquid inlet check valve 191 is arranged at the bottom end of the inner cavity of the plunger 19, a high-pressure sleeve 192 is fixedly arranged at the bottom end of the plunger hole, and a liquid outlet check valve 193 is arranged at the bottom end of the plunger hole; The inner cavities of the rotating transmission shaft 15, the conversion joint 16, and the power conversion cylinder 17 are connected, an annular cavity is formed between the filter cylinder 18 and the outer cylinder 14, the sleeve 110 is provided with a sleeve flow channel 1101 that penetrates along the axial direction, the power conversion cylinder 17 is provided with a first flow hole 171 that connects its inner cavity with the annular cavity, the filter cylinder 18 is provided with a second flow hole 181 that connects its inner cavity with the annular cavity, and the inner cavities of the filter cylinder 18 and the plunger 19 are connected; The interconnected inner cavities of the rotating transmission shaft 15, the conversion joint 16, the power conversion cylinder 17, the first flow hole 171, the annular cavity, and the sleeve flow channel 1101 form a first normal-pressure flow channel 11; the second flow hole 181, the inner cavities of the filter cylinder 18, the inner cavities of the plunger 19, the plunger hole, and the inner cavities of the high-pressure sleeve 192 form a first pressurized flow channel 12, and the upper end of the high-pressure hose 13 is connected to the bottom end of the high-pressure sleeve 192.

[0027] The principle of ultra-high pressure jet generation in this application: In the initial state, the liquid inlet check valve 191 and the liquid outlet check valve 193 are both closed, and the drilling fluid enters the inner cavity of the plunger 19 along the inner cavity of the rotating transmission shaft 15, the inner cavity of the conversion joint 16, the inner cavity of the power conversion cylinder 17, the first flow hole 171, the annular cavity, the second flow hole 181, and the inner cavity of the filter cylinder 18. When the plunger 19 follows the filter cylinder 18 and the power conversion cylinder 17 to move upward, the liquid inlet check valve 191 is opened, and the drilling fluid enters the plunger hole between the bottom end of the plunger 19 and the liquid outlet check valve 193; when the plunger 19 follows the filter cylinder 18 and the power conversion cylinder 17 to move downward, the liquid inlet check valve 191 is closed. When the drilling fluid pressure in the plunger hole between the bottom end of the plunger 19 and the liquid outlet check valve 193 reaches a certain value, the liquid outlet check valve 193 is opened, so that the pressurized drilling fluid is ejected along the high-pressure casing 192, the high-pressure hose 13, and the high-pressure nozzle 131 to form a jet; As the plunger 19 reciprocates axially, a pulsed ultra-high pressure jet is formed.

[0028] Preferably, the filter cartridge 18 is a cylindrical structure with a top end blocked.

[0029] Preferably, the upper joint 21 below the disc spring 25 is provided with a first through hole 212 for connecting the second normal pressure channel 211 and the inner cavity of the upper joint 21, and a bypass channel 213 passing through the inner cavity of the upper joint 21 to the outside, and a bypass nozzle 214 is provided in the bypass channel 213.

[0030] Preferably, a sealing cap 215 is fixedly disposed at the top end of the inner cavity of the upper joint 21 .

[0031] Preferably, Figure 2-Figure 4 As shown, a plurality of blade wings 35 are evenly arranged at the bottom end of the matrix 31 along the circumferential direction, and a plurality of PDC teeth 33 are arranged on each blade wing 35 .

[0032] Preferably, a plurality of gauge parts 36 are evenly arranged on the grooved outer cylinder 32 along the circumferential direction, and the gauge parts 36 include an outer arc-shaped gauge part 361 extending axially along the radial outer wall surface of the grooved outer cylinder 32, an inner arc-shaped gauge part 362 extending axially along the radial inner wall surface of the grooved outer cylinder 32, and a connecting part 363 connecting the bottom end of the outer arc-shaped gauge part 361 and the bottom end of the inner arc-shaped gauge part 362; A plurality of impregnated diamonds 34 are evenly arranged on the outer surfaces of the outer arc-shaped diameter-guaranteed portion 361 , the inner arc-shaped diameter-guaranteed portion 362 , and the connecting portion 363 along the extending direction of the generatrix.

[0033] Preferably, the radial outer wall surfaces of all the outer arc-shaped diameter-guaranteed portions 361 are located on the same cylindrical surface, and the radial inner wall surfaces of all the inner arc-shaped diameter-guaranteed portions 362 are located on the same cylindrical surface.

[0034] Preferably, the radial cross section of the connecting portion 363 is a semicircular ring structure.

[0035] Embodiment 2: The mechanical impact and water jet combined grooving stress unloading drilling method is implemented based on the mechanical impact and water jet combined grooving stress unloading drilling device, and the drilling method includes the following steps: Step 1, when the drill bit reaches the bottom of the well, the diamond impregnated 34 at the bottom of the grooved outer cylinder 32 contacts the bottom of the well before the PDC teeth 33; Apply drilling pressure and torque, under the joint action of the drilling fluid pressure in the casing 22, the bottom hole thrust on the drill bit, and the disc spring 25, the impact hammer 24 realizes the pulse impact on the drill bit, and the booster mechanism boosts the pressure of the drilling fluid and then sprays it through the first booster flow channel 12, the high-pressure hose 13, and the high-pressure nozzle 131 to form a high-pressure jet; Under the combined effects of drilling pressure, torque, pulse impact and high-pressure jet, the diamond-impregnated 34 cuts an annular groove on the end face of the bottom of the well to unload the bottom hole pressure; Step 2: The drill bit continues to drill, the depth of the annular groove continues to deepen, and the PDC teeth 33 begin to contact the bottom hole rock inside the annular groove and break it; Step 3, under the combined action of drilling pressure, torque, pulse impact and high-pressure jet, the impregnated diamond 34 cuts the annular groove and the PDC teeth 33 crush the rock inside the annular groove, thereby achieving combined rock breaking; During the process: The drilling fluid is sprayed outward along the first normal pressure flow channel 11, the sleeve flow channel 1101, the inner cavity of the casing 22, the second through hole 261, the inner cavity of the transmission core shaft 26, the conventional flow channel 311, and the conventional nozzle 312 to clean the diamond-impregnated 34 and the PDC teeth 33 and then transport the broken rock cuttings to the annulus.

[0036] The present invention realizes annular grooving on the bottom hole rock surface through the combined arrangement of a booster mechanism, an impact mechanism and a drill bit, thereby releasing the local stress of the bottom hole rock and reducing the difficulty of the bottom hole drill bit "eating into" the rock formation during drilling; at the same time, the mechanical impact produced by the impact mechanism can cause the drill bit to produce cracks on the bottom hole rock surface, thereby reducing the threshold pressure for the ultra-high pressure jet to cut into the rock; ultimately, the annular grooving of the bottom hole rock is achieved to unload the bottom hole rock stress, and the mechanical impact and ultra-high pressure water jet are combined to break the rock, thereby greatly improving the drilling rate.

[0037] Although the above describes the specific implementation mode of the present invention in conjunction with the accompanying drawings, it is not a limitation of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art on the basis of the technical solution of the present invention without creative work are still within the protection scope of the present invention.

Claims

1. Mechanical impact and water jet combined grooving stress unloading drilling device, characterized in that: It includes a booster mechanism, an impact mechanism, and a drill bit which are sequentially connected from top to bottom along the axial direction; The boost mechanism is provided with a first normal pressure channel and a first boost channel, and the lower end of the first boost channel is connected to a high pressure hose; The impact mechanism comprises an upper joint, a casing, and a lower joint which are coaxially fixedly connected in sequence, the upper end of the upper joint is fixedly connected to the lower end of the booster mechanism, a second normal pressure flow channel which runs axially through is arranged on the upper joint, an impact hammer is axially slidably matched in the middle of the upper joint, a disc spring is arranged between the step end face of the outer wall of the impact hammer and the step end face of the inner wall of the upper joint, a transmission core shaft is axially sealed and slidably matched in the middle of the lower joint, and a second through hole which is used to connect the inner cavity of the casing and the inner cavity of the transmission core shaft is arranged at the upper end of the transmission core shaft; the bottom end of the impact hammer and the upper end of the transmission core shaft are located in the inner cavity of the casing to realize the transmission of the impact; The drill bit comprises a mother body coaxially fixedly connected with a driving mandrel, a grooved outer cylinder is coaxially fixedly arranged at the radially outer bottom end of the mother body, a PDC tooth is arranged on the mother body, and a plurality of impregnated diamonds are evenly arranged on the grooved outer cylinder along the circumferential direction; when the drill bit reaches the bottom of the well, the impregnated diamonds contact the bottom of the well before the PDC teeth; The mother body is provided with a conventional flow channel which passes through the bottom end and is connected with the inner cavity of the transmission core shaft, and a conventional nozzle is provided at the bottom end of the conventional flow channel; The high-pressure hose is provided with a high-pressure nozzle after passing through the upper joint, the inner cavity of the casing, the driving core shaft, the mother body and the grooved outer cylinder.

2. The mechanical impact and water jet combined grooving stress unloading drilling device according to claim 1, characterized in that: The boost mechanism comprises an outer cylinder, wherein the outer cylinder comprises a rotating transmission shaft, a conversion joint, a power conversion cylinder, a filter cylinder, a plunger, and a sleeve from top to bottom; The rotating transmission shaft is coaxially fixedly connected with the outer cylinder, the conversion joint is coaxially fixedly arranged with the lower end of the rotating transmission shaft, and the lower part of the conversion joint is connected with the power conversion cylinder through a matching structure, and the matching structure converts the rotational motion of the conversion joint into the axial reciprocating motion of the power conversion cylinder; The filter cartridge is fixedly arranged at the bottom end of the power conversion cartridge, the upper part of the plunger is fixedly arranged at the bottom end of the inner cavity of the filter cartridge, the sleeve is coaxially fixedly connected with the outer cylinder, and a plunger hole matching with the plunger is arranged in the middle of the sleeve; a liquid inlet check valve is arranged at the bottom end of the inner cavity of the plunger, a high-pressure sleeve is fixedly arranged at the bottom end of the plunger hole, and a liquid outlet check valve is arranged at the bottom end of the plunger hole; The inner cavities of the rotating transmission shaft, the conversion joint and the power conversion cylinder are connected, an annular cavity is formed between the filter cylinder and the outer cylinder, a sleeve flow channel penetrating along the axial direction is provided on the sleeve, a first flow hole is provided on the power conversion cylinder to connect its inner cavity with the annular cavity, a second flow hole is provided on the filter cylinder to connect its inner cavity with the annular cavity, and the inner cavities of the filter cylinder and the plunger are connected; The interconnected rotating transmission shaft inner cavity, conversion joint inner cavity, power conversion cylinder inner cavity, first flow hole, annular cavity, and sleeve flow channel form a first normal pressure flow channel; the second flow hole, filter cylinder inner cavity, plunger inner cavity, plunger hole, and high-pressure sleeve inner cavity form a first boost flow channel.

3. The mechanical impact and water jet combined grooving stress unloading drilling device according to claim 2 is characterized in that: The filter cartridge is in a cylindrical structure with a top end blocked.

4. The mechanical impact and water jet combined grooving stress unloading drilling device according to claim 1, characterized in that: The upper joint below the disc spring is provided with a first through hole for connecting the second normal pressure flow channel and the inner cavity of the upper joint, and a bypass flow channel passing through the inner cavity of the upper joint to the outside, and a bypass nozzle is provided in the bypass flow channel.

5. The mechanical impact and water jet combined grooving stress unloading drilling device according to claim 1, characterized in that: A sealing cap is fixedly arranged on the top end of the inner cavity of the upper joint.

6. The mechanical impact and water jet combined grooving stress unloading drilling device according to claim 1, characterized in that: A plurality of blades are evenly arranged at the bottom end of the matrix along the circumferential direction, and a plurality of PDC teeth are arranged on each blade.

7. The mechanical impact and water jet combined grooving stress unloading drilling device according to claim 1, characterized in that: A plurality of gauge-keeping parts are evenly arranged on the grooved outer cylinder along the circumferential direction, and the gauge-keeping parts include an outer arc-shaped gauge-keeping part extending axially along the radial outer wall surface of the grooved outer cylinder, an inner arc-shaped gauge-keeping part extending axially along the radial inner wall surface of the grooved outer cylinder, and a connecting part connecting the bottom ends of the outer arc-shaped gauge-keeping part and the bottom ends of the inner arc-shaped gauge-keeping part; A plurality of impregnated diamonds are evenly arranged on the outer sides of the outer arc-shaped diameter-keeping portion, the inner arc-shaped diameter-keeping portion and the connecting portion along the extending direction of the generatrix.

8. The mechanical impact and water jet combined grooving stress unloading drilling device according to claim 7, characterized in that: The radial outer wall surfaces of all the outer arc-shaped diameter-keeping parts are located on the same cylindrical surface, and the radial inner wall surfaces of all the inner arc-shaped diameter-keeping parts are located on the same cylindrical surface.

9. The mechanical impact and water jet combined grooving stress unloading drilling device according to claim 8, characterized in that: The radial cross section of the connecting portion is a semicircular ring structure.

10. A mechanical impact and water jet combined grooving stress unloading drilling method, implemented based on the mechanical impact and water jet combined grooving stress unloading drilling device as claimed in any one of claims 2 to 9, characterized in that: The drilling method comprises the following steps: Step 1: When the drill bit reaches the bottom of the well, the diamond-impregnated bottom of the grooved outer tube contacts the bottom of the well before the PDC teeth; Apply drilling pressure and torque, and under the joint action of the drilling fluid pressure in the casing, the bottom hole thrust on the drill bit, and the disc spring, the impact hammer performs a pulse impact on the drill bit, and the booster mechanism boosts the pressure of the drilling fluid, which is then ejected through the first booster flow channel, the high-pressure hose, and the high-pressure nozzle to form a high-pressure jet; Under the combined effects of drilling pressure, torque, pulse impact and high-pressure jet, the diamond-impregnated rock cuts an annular groove on the bottom face of the well to unload the bottom hole pressure. Step 2: The drill bit continues to drill, the depth of the annular groove continues to deepen, and the PDC teeth begin to contact the bottom hole rock inside the annular groove and break it; Step 3: Under the combined action of drilling pressure, torque, pulse impact and high-pressure jet, the diamond-impregnated cutting of the annular groove and the PDC teeth continuously crush the rock inside the annular groove, thereby achieving combined rock breaking; During the process: The drilling fluid is sprayed outward along the first normal pressure flow channel, the sleeve flow channel, the casing cavity, the second through hole, the transmission core shaft cavity, the conventional flow channel, and the conventional nozzle to transport the broken rock cuttings into the annulus.

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