Mechanical impact annular cutting groove stress unloading well drilling speed increasing device and well drilling method

Abstract

The invention discloses a mechanical impact annular cutting groove stress unloading well drilling speed increasing device and a well drilling method, and belongs to the technical field of petroleum well drilling engineering.The mechanical impact annular cutting groove stress unloading well drilling speed increasing device comprises an impact tool and a drill bit; the impact tool comprises an outer cylinder, and a turbine shaft steel sleeve, a turbine shaft, a valve disc, a valve seat and an impactor are sequentially and coaxially arranged in the outer cylinder from top to bottom. A turbine is coaxially and fixedly arranged on the turbine shaft; the drill bit comprises a drill bit connector, a grooving unloading barrel matrix and an impact drill bit matrix, a plurality of annular grooving unloading stress teeth are arranged at the lower end of the grooving unloading barrel matrix, and impact crushing teeth are arranged at the lower end of the impact drill bit matrix. When the drill bit reaches the well bottom, the annular cutting groove unloading stress teeth make contact with the well bottom earlier than the impact crushing teeth. Continuous operation of annular grooving at the bottom of the well is achieved, meanwhile, through the structural arrangement of the impact tool above the drill bit, impact on an impactor is achieved through the pressure of drilling fluid, additional impact force is provided for the drill bit, and the destructive effect of the drill bit on rock is further improved.

Description

Technical Field

[0001] The invention belongs to the technical field of oil drilling engineering, and particularly relates to a mechanical impact annular grooving stress unloading drilling speed increasing device and a drilling method. Background Art

[0002] The compression effect of the static liquid column pressure and the in-situ stress on the deep bottom hole rock is enhanced, which increases the rock strength and plasticity, thereby reducing the mechanical drilling rate of the drill bit. At present, the mechanical drilling rate is mainly increased by improving the impact energy of downhole tools. However, the rock will cause damage to the drilling tools under high confining pressure conditions. At present, a method of using ultra-high pressure water jet to groove the bottom hole rock to unload the stress of the bottom hole rock, thereby reducing the rock strength and improving the drillability of the rock has been proposed. However, due to the heterogeneity of the rock and the pulsed characteristics of the ultra-high pressure water jet, the grooving of the bottom hole rock is discontinuous, which limits the efficient utilization of this method.

[0003] Based on this, considering from the perspective of the continuity of the bottom hole rock grooving, the present application proposes a mechanical impact annular grooving stress unloading drilling speed increasing device and a drilling method. The continuous operation of the bottom hole annular grooving is realized through the setting of the structure of the drill bit itself, solving the defect of discontinuous bottom hole grooving caused by the pulsed characteristics of the ultra-high pressure water jet. The setting of the impact tool above the drill bit provides an additional impact force for the drill bit, further increasing the damage effect of the drill bit on the rock. Summary of the Invention

[0004] The purpose of the invention is to overcome the above-mentioned deficiencies of the prior art and provide a mechanical impact annular grooving stress unloading drilling speed increasing device.

[0005] To achieve the above purpose, the invention adopts the following technical solutions:

[0006] A mechanical impact annular grooving stress unloading drilling speed increasing device includes an impact tool and a drill bit;

[0007] The impact tool includes an outer cylinder body. Inside the outer cylinder body, a turbine shaft steel sleeve, a turbine shaft, a valve disc, a valve seat, and an impactor are coaxially arranged from top to bottom in sequence. The radial outer side of the turbine shaft steel sleeve is fixedly connected to the inner side of the outer cylinder body. The upper end of the turbine shaft is rotationally matched with the turbine shaft steel sleeve. The lower end of the turbine shaft is fixedly connected to the valve disc. The radial outer side of the valve disc is rotationally matched with the inner side of the outer cylinder body. The radial outer side of the valve seat is fixedly connected to the inner side of the outer cylinder body and the radial inner side is rotationally matched with the valve disc. The impactor is axially slidably matched with the inner side of the outer cylinder body;

[0008] An upper annular space is formed between the turbine shaft and the outer cylinder body. Flow channel holes axially penetrating are provided on the turbine shaft steel sleeve, the valve disc, and the valve seat. A turbine is coaxially and fixedly arranged on the turbine shaft;

[0009] A fluid buffer zone is formed in the inner cavity of the outer cylinder between the valve seat and the impactor, and a through impact drilling fluid flow path is provided in the middle of the impactor.

[0010] The drill bit includes a drill bit sub, a grooving unloading cylinder body, and an impact drill bit body. The drill bit sub is coaxially and fixedly connected to the lower end of the impactor. The upper end of the impact drill bit body is coaxially and fixedly connected to the radial inner side of the lower end of the drill bit sub. The grooving unloading cylinder body is located outside the impact drill bit body and its upper end is connected to the lower end of the drill bit sub.

[0011] A plurality of annular grooving unloading stress teeth are uniformly arranged along the circumferential direction at the lower end of the grooving unloading cylinder body, and impact breaking teeth are arranged at the lower end of the impact drill bit body. When the drill bit reaches the bottom of the well, the annular grooving unloading stress teeth contact the bottom of the well prior to the impact breaking teeth.

[0012] Preferably, a through first drilling fluid flow path is provided in the drill bit sub, and a second drilling fluid flow path communicating with the first drilling fluid flow path is provided in the impact drill bit body.

[0013] A nozzle flow path extending to the bottom end is provided in the impact drill bit body. The upper end of the nozzle flow path communicates with the second drilling fluid flow path, and a nozzle is provided at the lower end of the nozzle flow path.

[0014] Preferably, an annular groove is formed on the radial outer side surface of the impactor, and an upper spring is arranged in the annular groove. The upper end of the upper spring is fixed on the upper end surface of the annular groove, and the lower end of the upper spring is fixed on the inner stepped end surface of the outer cylinder.

[0015] Preferably, the upper end of the grooving unloading cylinder body is in axial sliding fit with the radial outer side of the lower end of the drill bit sub.

[0016] An annular space is formed between the radial inner side surface of the grooving unloading cylinder body and the radial outer side surface of the impact drill bit body.

[0017] An annular step is coaxially and fixedly arranged on the radial inner side surface of the grooving unloading cylinder body, and an axial sliding fit is carried out between the radial inner side of the annular step and the radial outer side surface of the impact drill bit body.

[0018] A lower spring is arranged in the annular space between the bottom end surface of the drill bit sub and the top end surface of the annular step.

[0019] Preferably, a plurality of tooth brackets are uniformly arranged along the circumferential direction at the lower end of the grooving unloading cylinder body, and an annular grooving unloading stress tooth is arranged on each tooth bracket.

[0020] Preferably, all the annular grooving unloading stress teeth are arranged on the same side in the circumferential direction of the corresponding tooth brackets.

[0021] Preferably, one end of the central axis of the annular grooving stress unloading tooth, which is far away from the tooth support where it is located, inclines downward.

[0022] Preferably, a centralizer is arranged in the upper annular space above the turbine, and an axially penetrating centralizer flow through hole is arranged on the centralizer.

[0023] The present invention also discloses a mechanical impact annular grooving stress unloading drilling method.

[0024] A mechanical impact annular grooving stress unloading drilling method is implemented based on a mechanical impact annular grooving stress unloading drilling speed-up device. The drilling method includes the following steps:

[0025] Step 1: When the drill bit reaches the bottom of the well, the annular grooving stress unloading tooth contacts the bottom of the well prior to the impact crushing tooth. Under the action of the drilling pressure, the lower spring is compressed to transmit the drilling pressure to the annular grooving stress unloading tooth;

[0026] Under the combined action of the drilling pressure and torque, the annular grooving stress unloading tooth cuts a circular groove on the bottom end face of the drilling well bottom to unload the bottom hole pressure;

[0027] Step 2: The drill bit continues to drill, the depth of the circular groove continuously deepens, and the impact crushing tooth begins to contact the bottom hole rock inside the circular groove and break it;

[0028] Step 3: Under the action of the drilling pressure and torque, the cutting of the circular groove by the annular grooving stress unloading tooth and the breaking of the rock inside the circular groove by the impact crushing tooth continue, realizing combined rock breaking;

[0029] During this process:

[0030] The drilling fluid enters the upper annular space through the flow channel holes on the turbine shaft sleeve, flows through the turbine, and the turbine drives the turbine shaft and the valve disc to rotate. When the flow channel hole on the valve disc rotates to be not communicated with the flow channel hole on the valve seat, the drilling fluid in the upper annular space is pressurized; when the flow channel hole on the valve disc rotates to be communicated with the flow channel hole on the valve seat, the pressurized drilling fluid flows from the upper annular space to the fluid buffer area to impact the impactor, forming an impact force;

[0031] The impact force acts on the drill bit, and jointly with the drilling pressure and torque, accelerates the destruction of the rock;

[0032] The drilling fluid entering the fluid buffer area is sprayed outwards through the impact drilling fluid flow channel, the first drilling fluid flow channel, the second drilling fluid flow channel, the nozzle flow channel, and the nozzle, washes the impact crushing tooth and the annular grooving stress unloading tooth, and then carries the broken rock chips through the gap of the tooth support to the annulus.

[0033] The beneficial effects of the present invention are:

[0034] (1) The present invention realizes continuous operation of bottom-hole annular grooving through the setting of the structure of the drill bit itself. At the same time, through the setting of the structure of the impact tool above the drill bit, the impact on the impactor is realized by using the drilling fluid pressure, that is, without using an additional power mechanism, an additional impact force is provided for the drill bit, further increasing the destructive effect of the drill bit on the rock.

[0035] (2) In the present invention, the upper spring converts the impact of the drilling fluid on the impactor into a soft impact, playing a role in protecting the impact crushing teeth; the lower spring converts the impact of the impact tool above the drill bit into a soft impact, playing a role in protecting the annular grooving unloading stress teeth.

[0036] (3) In the present invention, a number of annular grooving unloading stress teeth are uniformly arranged along the circumferential direction at the lower end of the grooving unloading cylinder body. In this arrangement, when some of the annular grooving unloading stress teeth are damaged, the annular grooving can still be cut by other annular grooving unloading stress teeth, without affecting the use. Description of the Drawings

[0037] The specification drawings forming a part of this application are used to provide a further understanding of this application. The schematic embodiments of this application and their descriptions are used to explain this application and do not constitute an improper limitation of this application.

[0038] Figure 1 is a schematic structural diagram of the mechanical impact annular grooving stress unloading drilling speed increasing device of the present invention;

[0039] Figure 2 is Figure 1 a partial enlarged view of A in

[0040] Figure 3 is a schematic cooperation diagram of the drill bit joint and the grooving unloading cylinder body in the present invention;

[0041] Wherein:

[0042] 11 - Turbine shaft steel sleeve, 12 - Turbine shaft, 13 - Valve disc, 14 - Valve seat, 15 - Impactor, 151 - Impact drilling fluid flow channel, 152 - Upper spring, 16 - Upper annular space, 17 - Turbine, 18 - Fluid buffer zone, 19 - Centralizer, 110 - Drill string outer cylinder, 111 - Spring outer cylinder, 112 - Upper joint;

[0043] 21 - Drill bit joint, 22 - Lower spring, 23 - Grooving unloading cylinder body, 231 - Annular step, 24 - First drilling fluid flow channel, 25 - Second drilling fluid flow channel, 26 - Nozzle, 27 - Annular grooving unloading stress teeth, 28 - Impact crushing teeth, 29 - Tooth support, 210 - Impact drill bit body, 2101 - Nozzle flow channel. Detailed Embodiments

[0044] It should be noted that the following detailed description is illustrative and is intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the technical field to which this application belongs.

[0045] 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 forms are also intended to include the plural forms. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they specify the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0046] In the present invention, terms such as "upper", "lower", "bottom", "top", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. They are only relational terms determined for the convenience of describing the structural relationship of each component or element of the present invention and do not specifically refer to any component or element in the present invention and should not be construed as a limitation to the present invention.

[0047] In the present invention, terms such as "connected" and "coupled" should be understood in a broad sense and may mean a fixed connection, an integral connection, or a detachable connection; it may be directly connected or indirectly connected through an intermediate medium. For those skilled in the relevant scientific research or technology in this field, the specific meanings of the above terms in the present invention can be determined according to specific circumstances and should not be construed as a limitation to the present invention.

[0048] The present invention will be further described below with reference to the drawings and embodiments.

[0049] Example 1:

[0050] As Figure 1 shown, a mechanical impact ring grooving stress unloading drilling speed-up device includes an impact tool and a drill bit;

[0051] The impact tool includes an outer cylinder body. Inside the outer cylinder body, a turbine shaft steel sleeve 11, a turbine shaft 12, a valve disc 13, a valve seat 14, and an impactor 15 are coaxially arranged in sequence from top to bottom. The radially outer side of the turbine shaft steel sleeve 11 is fixedly connected to the inner side of the outer cylinder body. The upper end of the turbine shaft 12 is rotationally matched with the turbine shaft steel sleeve 11. The lower end of the turbine shaft 12 is fixedly connected to the valve disc 13. The radially outer side of the valve disc 13 is rotationally matched with the inner side of the outer cylinder body. The radially outer side of the valve seat 14 is fixedly connected to the inner side of the outer cylinder body and the radially inner side is rotationally matched with the valve disc 13. The impactor 15 is axially slidably matched with the inner side of the outer cylinder body. Specifically, in this application, the outer cylinder body includes a drill string outer cylinder 110 and a spring outer cylinder 111 that are coaxially fixed. Among them, the turbine shaft steel sleeve 11, the turbine shaft 12, the valve disc 13, and the valve seat 14 are located inside the drill string outer cylinder 110, and the impactor 15 is located inside the spring outer cylinder 111. The lower end of the impactor 15 extends out of the spring outer cylinder 111 and is connected to the drill bit joint 21, and the upper end of the drill string outer cylinder 110 is coaxially connected to the upper joint 112.

[0052] An upper annular space 16 is formed between the turbine shaft 12 and the outer cylinder body. The turbine shaft steel sleeve 11, the valve disc 13, and the valve seat 14 are all provided with axially penetrating flow channel holes, and a turbine 17 is coaxially and fixedly arranged on the turbine shaft 12.

[0053] A fluid buffer zone 18 is formed in the inner cavity of the outer cylinder body between the valve seat 14 and the impactor 15. A through impact drilling fluid flow channel 151 is provided in the middle of the impactor 15.

[0054] The drill bit includes a drill bit joint 21, a grooving unloading cylinder body 23, and an impact drill bit body 210. The drill bit joint 21 is coaxially and fixedly connected to the lower end of the impactor 15. The upper end of the impact drill bit body 210 is coaxially and fixedly connected to the radially inner side of the lower end of the drill bit joint 21. The grooving unloading cylinder body 23 is located outside the impact drill bit body 210 and the upper end is connected to the lower end of the drill bit joint 21. Among them, the upper end of the impact drill bit body 210 is threadedly connected to the radially inner side of the lower end of the drill bit joint 21 for transmitting the drilling pressure and torque.

[0055] A plurality of annular grooving unloading stress teeth 27 are uniformly arranged along the circumferential direction at the lower end of the grooving unloading cylinder body 23 to realize annular grooving of the rock. An impact crushing tooth 28 is provided at the lower end of the impact drill bit body 210 to realize the crushing of the rock inside the annular groove. When the drill bit reaches the bottom of the well, the annular grooving unloading stress teeth 27 contact the bottom of the well prior to the impact crushing teeth 28. In this application, the annular grooving unloading stress teeth 27 are PDC teeth.

[0056] Preferably, a through first drilling fluid flow channel 24 is provided in the drill bit sub 21, and a second drilling fluid flow channel 25 communicating with the first drilling fluid flow channel 24 is provided in the percussion bit matrix 210;

[0057] A nozzle flow channel 2101 extending to the bottom end is provided in the percussion bit matrix 210. The upper end of the nozzle flow channel 2101 communicates with the second drilling fluid flow channel 25, and a nozzle 26 is provided at the lower end of the nozzle flow channel 2101.

[0058] Preferably, an annular groove is formed on the radial outer surface of the impactor 15. An upper spring 152 is arranged in the annular groove. The upper end of the upper spring 152 is fixed on the upper end surface of the annular groove, and the lower end of the upper spring 152 is fixed on the inner stepped end surface of the outer cylinder.

[0059] The upper spring 152 converts the impact of the drilling fluid on the impactor 15 into a soft impact, that is, it plays a buffering role, so as to protect the impact crushing teeth 28.

[0060] Preferably, the upper end of the grooving unloading cylinder matrix 23 is in axial sliding fit with the radial outer side of the lower end of the drill bit sub 21; specifically, as Figure 3 shown, a spline groove matching with the spline on the radial outer surface of the lower end of the drill bit sub 21 is provided on the radial inner surface of the upper end of the grooving unloading cylinder matrix 23 for transmitting the torque of the drill string and realizing axial sliding fit;

[0061] An annular space is formed between the radial inner surface of the grooving unloading cylinder matrix 23 and the radial outer surface of the percussion bit matrix 210;

[0062] An annular step 231 is coaxially and fixedly arranged on the radial inner surface of the grooving unloading cylinder matrix 23. Axial sliding fit is carried out between the radial inner side of the annular step 231 and the radial outer surface of the percussion bit matrix 210;

[0063] A lower spring 22 is arranged in the annular space between the bottom end surface of the drill bit sub 21 and the top end surface of the annular step 231. The upper end of the lower spring 22 abuts and is fixedly connected with the bottom end surface of the drill bit sub 21, and the lower end of the lower spring 22 abuts and is fixedly connected with the top end surface of the annular step 231; the lower spring 22 converts the impact of the upper impact tool of the drill bit into a soft impact, that is, it plays a buffering role, so as to protect the annular grooving unloading stress teeth 27.

[0064] Preferably, a plurality of tooth brackets 29 are uniformly arranged along the circumferential direction at the lower end of the grooving unloading cylinder matrix 23, and an annular grooving unloading stress tooth 27 is arranged on each tooth bracket 29.

[0065] Preferably, all the annular grooved stress-relieving teeth 27 are arranged on the same side in the circumferential direction of the corresponding tooth support 29. For example, in the top view of Figure 2 looking at it, all the annular grooved stress-relieving teeth 27 are arranged on the front side in the clockwise circumferential direction of the corresponding tooth support 29.

[0066] Preferably, the end of the central axis of the annular grooved stress-relieving tooth 27 away from the tooth support 29 where it is located inclines downward, so that it has a better cutting effect on the rock.

[0067] Preferably, a centralizer 19 is arranged in the upper annular space 16 above the turbine 17, and an axially penetrating centralizer flow-through through-hole is arranged on the centralizer 19.

[0068] Embodiment 2:

[0069] A mechanical impact annular grooving stress-relieving drilling method is implemented based on the mechanical impact annular grooving stress-relieving drilling speed-up device in Embodiment 1. The drilling method includes the following steps:

[0070] Step 1: When the drill bit reaches the bottom of the well, the annular grooved stress-relieving tooth 27 contacts the bottom of the well prior to the impact crushing tooth 28. Under the action of the drilling pressure, the lower spring 22 is compressed to transmit the drilling pressure to the annular grooved stress-relieving tooth 27;

[0071] Under the combined action of the drilling pressure and torque, the annular grooved stress-relieving tooth 27 cuts a circular groove on the bottom end face of the drilling well bottom to relieve the bottom pressure;

[0072] Step 2: The drill bit continues to drill, the depth of the circular groove continuously deepens, and the impact crushing tooth 28 starts to contact the bottom rock inside the circular groove and break it;

[0073] Step 3: Under the action of the drilling pressure and torque, the cutting of the circular groove by the annular grooved stress-relieving tooth 27 and the breaking of the rock inside the circular groove by the impact crushing tooth 28 continue, realizing combined rock breaking;

[0074] During this process:

[0075] The drilling fluid enters the upper annular space 16 along the flow channel holes on the turbine shaft steel sleeve 11, flows through the turbine 17. The turbine 17 drives the turbine shaft 12 and the valve disc 13 to rotate. When the flow channel holes on the valve disc 13 rotate to be not communicated with the flow channel holes on the valve seat 14, the drilling fluid in the upper annular space 16 is pressurized; when the flow channel holes on the valve disc 13 rotate to be communicated with the flow channel holes on the valve seat 14, the pressurized drilling fluid flows from the upper annular space 16 to the fluid buffer zone 18 to impact the impactor 15, forming an impact force;

[0076] The impact force acts on the drill bit, and together with the drilling pressure and torque, it accelerates the destruction of the rock;

[0077] The drilling fluid entering the fluid buffer 18 is ejected outward through the impact drilling fluid flow channel 151, the first drilling fluid flow channel 24, the second drilling fluid flow channel 25, the nozzle flow channel 2101, and the nozzle 26. After cleaning the impact crushing teeth 28 and the annular grooving stress unloading teeth 27, the carried crushed rock cuttings are transported to the annulus through the gaps of the tooth support 29.

[0078] Through the setting of the structure of the drill bit itself, the present invention realizes the continuous operation of the bottom hole annular grooving. At the same time, due to the setting of the structure of the impact tool above the drill bit, the impact on the impactor is realized by using the drilling fluid pressure, that is, an additional impact force is provided for the drill bit without using an additional power mechanism, further increasing the destruction effect of the drill bit on the rock.

[0079] Although the specific implementation manners of the present invention are described above in conjunction with the drawings, they are not limitations on the present invention. Those skilled in the art should understand that various modifications or deformations that can be made without creative efforts on the basis of the technical solutions of the present invention are still within the protection scope of the present invention.

Claims

1. A mechanical impact annular grooving stress unloading drilling speed-up device, comprising an impact tool and a drill bit; characterized in that: The impact tool comprises an outer cylinder, in which a turbine shaft steel sleeve, a turbine shaft, a valve disc, a valve seat, and an impactor are coaxially arranged in sequence from top to bottom; the radial outer side surface of the turbine shaft steel sleeve is fixedly connected to the inner side surface of the outer cylinder, the upper end of the turbine shaft is rotationally matched with the turbine shaft steel sleeve, the lower end of the turbine shaft is fixedly connected to the valve disc, the radial outer side surface of the valve disc is rotationally matched with the inner side surface of the outer cylinder, the radial outer side surface of the valve seat is fixedly connected to the inner side surface of the outer cylinder, the radial inner side surface is rotationally matched with the valve disc, and the impactor is axially slidably matched with the inner side surface of the outer cylinder; An upper annular space is formed between the turbine shaft and the outer cylinder, and the turbine shaft steel sleeve, valve disc, and valve seat are all provided with flow channel holes that penetrate in the axial direction, and a turbine is coaxially fixedly arranged on the turbine shaft; The inner cavity of the outer cylinder between the valve seat and the impactor forms a fluid buffer zone, and a through impact drilling fluid flow channel is provided in the middle of the impactor; The drill bit comprises a drill bit joint, a groove unloading cylinder body, and an impact drill bit body. The drill bit joint is coaxially fixedly connected to the lower end of the impactor. The upper end of the impact drill bit body is coaxially fixedly connected to the radial inner side of the lower end of the drill bit joint. The groove unloading cylinder body is located outside the impact drill bit body and the upper end is connected to the lower end of the drill bit joint. The lower end of the groove unloading cylinder body is evenly provided with a plurality of annular groove unloading stress teeth along the circumferential direction, and the lower end of the impact drill bit body is provided with impact crushing teeth; when the drill bit reaches the bottom of the well, the annular groove unloading stress teeth contact the bottom of the well before the impact crushing teeth.

2. The mechanical impact annular groove stress unloading drilling speed-up device according to claim 1, characterized in that: A first drilling fluid flow channel is provided in the drill bit joint, and a second drilling fluid flow channel connected to the first drilling fluid flow channel is provided in the impact drill bit body; A nozzle flow channel extending to the bottom end is arranged in the impact drill bit body, the upper end of the nozzle flow channel is connected to the second drilling fluid flow channel, and a nozzle is arranged at the lower end of the nozzle flow channel.

3. The mechanical impact annular groove stress unloading drilling speed-up device according to claim 2, characterized in that: An annular groove is formed on the radial outer side of the impactor, an upper spring is arranged in the annular groove, the upper end of the upper spring is fixed on the upper end surface of the annular groove, and the lower end of the upper spring is fixed on the inner step end surface of the outer cylinder.

4. The mechanical impact annular groove stress unloading drilling speed-up device according to claim 2, characterized in that: The upper end of the groove unloading cylinder body is axially slidably matched with the radial outer side of the lower end of the drill bit joint; An annular space is formed between the radial inner side surface of the groove unloading cylinder body and the radial outer side surface of the impact drill bit body; An annular step is coaxially fixedly arranged on the radial inner side of the groove unloading cylinder body, and the radial inner side of the annular step is axially slidably matched with the radial outer side of the impact drill bit body; A lower spring is arranged in the annular space between the bottom end surface of the drill bit joint and the top end surface of the annular step.

5. The mechanical impact annular groove stress unloading drilling speed-up device according to claim 2, characterized in that: A plurality of tooth brackets are evenly arranged along the circumferential direction at the lower end of the groove unloading cylinder body, and each tooth bracket is provided with an annular groove unloading stress tooth.

6. The mechanical impact annular groove stress unloading drilling speed-up device according to claim 5, characterized in that: All the annular groove stress-unloading teeth are arranged on the same side of the circumferential direction of the corresponding tooth bracket.

7. The mechanical impact annular groove stress unloading drilling speed-up device according to claim 2, characterized in that: The center axis of the annular groove stress unloading tooth is inclined downward away from one end of the tooth support where it is located.

8. The mechanical impact annular groove stress unloading drilling speed-up device according to claim 2, characterized in that: A centralizer is arranged in the upper annular space on the upper part of the turbine, and a centralizer flow through hole penetrating along the axial direction is arranged on the centralizer.

9. A mechanical impact annular groove stress unloading drilling method, implemented based on the mechanical impact annular groove stress unloading drilling speed-up device according to any one of claims 2 to 8, characterized in that: The drilling method comprises the following steps: Step 1: When the drill bit reaches the bottom of the well, the annular groove stress unloading tooth contacts the bottom of the well before the impact crushing tooth, and the lower spring is compressed under the action of the drilling pressure to transmit the drilling pressure to the annular groove stress unloading tooth; Under the combined effect of drilling pressure and torque, the annular groove unloading stress tooth cuts an annular groove on the end face of the drilling bottom 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 impact crushing teeth begin to contact the bottom rock inside the annular groove and crush it; Step 3: Under the action of drilling pressure and torque, the annular groove unloading stress teeth continuously cut the annular groove and the impact crushing teeth continuously crush the rock inside the annular groove, thereby achieving combined rock breaking; During the process: The drilling fluid enters the upper annular space along the flow channel hole on the turbine shaft steel sleeve and flows through the turbine. The turbine drives the turbine shaft and the valve disc to rotate. When the flow channel hole on the valve disc rotates to be disconnected from the flow channel hole on the valve seat, the drilling fluid in the upper annular space is pressurized. When the flow channel hole on the valve disc rotates to be connected with the flow channel hole on the valve seat, the pressurized drilling fluid flows from the upper annular space to the fluid buffer zone to impact the impactor, forming an impact force. The impact force acts on the drill bit, and combined with the drilling pressure and torque, accelerates the destruction of the rock; The drilling fluid entering the fluid buffer zone is sprayed outward through the impact drilling fluid flow channel, the first drilling fluid flow channel, the second drilling fluid flow channel, the nozzle flow channel, and the nozzle, and cleans the impact crushing teeth and the annular groove unloading stress teeth, and then carries the crushed rock cuttings to the annulus through the gap of the tooth bracket.

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