Downhole electric drilling tool for gas drilling and method of use thereof

Abstract

The application provides a downhole electric drilling tool for gas drilling and an application method thereof, wherein the downhole electric drilling tool comprises a drill string joint, a power unit, a transmission unit and a drill bit, the drill string joint is fixedly connected to the upper end of the power unit, and the drill string joint is used for connecting the electric drilling tool with an upper drill string; the transmission unit and the drill bit are sequentially connected to the lower end of the power unit, the power unit comprises a power supply assembly and a motor, the power supply assembly is connected with the motor, and the power supply assembly can provide power for the motor; the transmission unit comprises a speed reducer, the speed reducer is connected between the motor and the drill bit, and is used for transmitting the power output by the motor to the drill bit to drive the drill bit to drill. The application adopts a mode that high-density storage batteries directly supply power to the electric drilling tool, and then a planetary reducer is used to obtain the torque required for sliding drilling of gas drilling, and the driving mode of a gas screw is abandoned, and the operation capacity and reliability are greatly improved.

Description

Technical Field

[0001] This invention relates to the field of oil and gas drilling (exploration) equipment technology, and more specifically, to a downhole electric drilling tool for gas drilling and its application method. Background Technology

[0002] Gas drilling technology offers advantages such as faster drilling speed, improved leakage control, and reservoir protection, and has been widely applied in oil and gas blocks in Sichuan, Chongqing, Xinjiang, and Qinghai. In recent years, with the increasing emphasis on unconventional tight gas development, gas drilling (nitrogen) technology has been used for drilling into target formations, demonstrating significant effectiveness in four aspects: solving the problems of low-pressure and tight reservoir protection, maximizing the original reservoir productivity, reducing the environmental problems caused by large-scale acid fracturing operations, and significantly reducing stimulation costs.

[0003] However, current nitrogen drilling of target formations is mainly carried out using a "dedicated drilling" approach, primarily employing "blind drilling" techniques in deviated / horizontal well sections. This lack of wellbore trajectory control makes it impossible to guarantee reservoir encounter rates or achieve the reservoir exposure area required by the construction unit, thus significantly limiting the promotion and development of nitrogen drilling technology for target formations. The main reasons for this are as follows:

[0004] ① There is a lack of screws usable under pure gas conditions. Currently, there are no successful application cases of screws under pure gas circulating media conditions, both domestically and internationally. Only a few successful application cases of screws under foam circulating media conditions are known. Practical application experience shows that due to the high compressibility of gas, it is not suitable for driving screws to directionally break rocks.

[0005] ② Monitoring while drilling (WWP) methods under pure gas conditions are immature. Currently, the main media used for WWP information transmission under gas drilling conditions, both domestically and internationally, are electromagnetic waves and microwaves, with transmission methods including one-time transmission and relay transmission. From practical experience, due to factors such as the power consumption of conventional battery power, both methods suffer from signal instability and limited transmission depth. Summary of the Invention

[0006] The purpose of this invention is to address at least one of the aforementioned shortcomings of the prior art. For example, one objective of this invention is to provide a downhole electric drilling tool for gas drilling and its application method, to solve the technical problems in the prior art such as the inapplicability of the drive screw under pure gas conditions and unstable signal transmission.

[0007] To achieve the above objectives, the present invention provides a downhole electric drilling tool for gas drilling. The downhole electric drilling tool may include a drill string connector, a power unit, a transmission unit, and a drill bit. The drill string connector is fixedly connected to the upper end of the power unit and is used to connect the electric drilling tool to the upper drill string. The transmission unit and the drill bit are sequentially connected to the lower end of the power unit. The power unit includes a power supply component and a motor, which are connected to the motor and provide power to the motor. The transmission unit includes a reducer connected between the motor and the drill bit, which is used to transmit the power output by the motor to the drill bit, driving the drill bit to drill.

[0008] Alternatively, the power assembly may include a battery casing, a central tube, and a battery pack. The central tube passes through the battery casing, and an annular space is formed between the outer wall of the central tube and the inner wall of the battery casing. The battery pack is disposed in the annular space. The battery pack includes at least one battery segment. The outer wall of the battery has several grooves along the axial direction, and the inner wall of the battery casing has several inwardly protruding fixing supports along the axial direction. The grooves and fixing supports correspond one-to-one and cooperate with each other to circumferentially fix the battery in the battery casing.

[0009] Optionally, the power assembly may further include a first intermediate connector, and the battery pack includes a first battery and a second battery. The first intermediate connector is disposed between the first battery and the second battery, and the first intermediate connector connects the first battery and the second battery end to end to form the battery pack. A main channel is opened at the center of the first intermediate connector, and the main channel communicates with the inner cavity of the central tube. At least one first line channel is also opened on the first intermediate connector, and the first battery and the second battery can be connected in series through a connecting wire passing through the first line channel.

[0010] Alternatively, a second intermediate connector may be installed between the power supply component and the motor. The second intermediate connector has at least one second line channel, and the power supply component and the motor can be connected in series through a connecting wire passing through the second line channel.

[0011] Alternatively, the inner cavity of the drill string joint, the inner cavity at the center of the power unit, the inner cavity of the transmission unit, and the inner cavity of the drill bit can be interconnected to form a fluid channel so that compressed gas can pass through it.

[0012] Alternatively, a throttle valve can be installed in the inner cavity of the motor according to downhole conditions, and the compressed gas can be throttled and depressurized through the throttle valve to cool the motor.

[0013] Alternatively, the motor may be an oil-filled submersible motor, and the reducer may be a planetary gear reducer.

[0014] Alternatively, the drill string connector and the battery casing can be connected by threads, the drill string connector and the central tube can be connected by threads, the battery casing and the first intermediate connector can be connected by threads, and the central tube and the first intermediate connector can be connected by threads; set screws are installed at both ends of the inner wall of the battery casing; seals are installed between the drill string connector and the battery casing, between the drill string connector and the central tube, between the battery casing and the first intermediate connector, and between the central tube and the first intermediate connector to seal the various connections.

[0015] Alternatively, the transmission unit may further include a drill bit connecting shaft mounted between the reducer and the drill bit for transmitting torque from the reducer to the drill bit.

[0016] Another aspect of the present invention provides a method for applying a downhole electric drilling tool for gas drilling in drilling operations. The method uses the downhole electric drilling tool for gas drilling as described above. The method includes connecting the drill string connector to the upper drill pipe, lowering the drill pipe along the wellhead to lower the downhole electric drilling tool to a designated position downhole, controlling the start of the motor, transmitting power to the drill bit through the reducer to drive the drill bit to perform drilling operations, and inputting compressed gas into the drill bit through the inner cavity of the drill string connector, the inner cavity of the power unit, and the inner cavity of the transmission unit, thereby carrying away the rock cuttings generated by the drill bit from the bottom of the well.

[0017] Compared with the prior art, the beneficial effects of the present invention include at least one of the following:

[0018] 1. This invention uses a high-density battery to directly power the electric drilling tool, and then obtains the torque required for gas drilling sliding drilling through a planetary reducer. This eliminates the need for a gas screw drive, and significantly improves the working capacity and reliability.

[0019] 2. Compared with traditional electric drilling tools, it does not require customized special drilling tools with complex structures and high costs for surface power supply, nor does it require customized downhole generators. It can be implemented with conventional drilling tools, thus saving costs to the maximum extent.

[0020] 3. The batteries are installed in segments. If a battery is damaged, simply remove the segment containing the damaged battery for repair. The remaining batteries can still be charged and reused.

[0021] 4. The battery is installed in segments. Based on the predicted working time of a single drilling motor, the number of battery segments is adjusted to adjust the stored power.

[0022] 5. Due to the use of high-density batteries, the EMWD (Electromagnetic Wave Measurement While Drilling) instrument can be powered simultaneously, thereby increasing the existing electromagnetic wave transmission power by hundreds of times and significantly improving the operating depth of gas drilling directional and horizontal wells. Attached Figure Description

[0023] The above and other objects and / or features of the present invention will become clearer from the following description taken in conjunction with the accompanying drawings, in which:

[0024] Figure 1 A cross-sectional view of the overall structure of a downhole electric drilling tool for gas drilling, an exemplary embodiment of the present invention, is shown.

[0025] Figure 2 A cross-sectional view of the drill string joint of a downhole electric drilling tool for gas drilling, according to an exemplary embodiment of the present invention, is shown.

[0026] Figure 3 A cross-sectional view of the first intermediate joint of a downhole electric drilling tool for gas drilling, an exemplary embodiment of the present invention, is shown.

[0027] Figure 4 A cross-sectional view of the second intermediate joint of a downhole electric drilling tool for gas drilling, an exemplary embodiment of the present invention, is shown.

[0028] Figure 5 A cross-sectional view of the battery casing of a downhole electric drilling tool for gas drilling, an exemplary embodiment of the present invention, is shown.

[0029] Figure 6 A cross-sectional view of the reducer of a downhole electric drilling tool for gas drilling, an exemplary embodiment of the present invention, is shown.

[0030] Explanation of reference numerals in the attached figures:

[0031] 1. Drill string connector; 11. Central flow channel; 2. Power unit; 21. Power supply assembly; 211. Battery casing; 2111. Set screw; 212. Central tube; 213. Battery pack; 2131. First battery; 2132. Second battery; 214. First intermediate connector; 2141. Main flow channel; 2142. First circuit channel; 215. Second intermediate connector; 2151. Second circuit channel; 22. Motor; 3. Transmission unit; 31. Reducer; 311. Seal; 32. Drill bit connecting shaft; 4. Drill bit. Detailed Implementation

[0032] In the following sections, the downhole electric drilling tool for gas drilling and its application method of the present invention will be described in detail with reference to exemplary embodiments.

[0033] In the description of this application, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0034] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0035] In the description of this application, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0036] In gas drilling technologies, the primary approach is "dedicated drilling" of the target formation, mainly using "blind drilling" techniques in deviated / horizontal well sections. This lack of wellbore trajectory control makes it difficult to guarantee reservoir encounter rates and achieve the required reservoir exposure area, significantly limiting the promotion and development of nitrogen drilling technology for target formations. The main problems include: a lack of screws usable under pure gas conditions. Currently, there are no successful application cases of screws under pure gas circulation media conditions, only a few successful cases under foam circulation media conditions. Practical application experience shows that due to the high compressibility of gas, it is not suitable for driving screws for directional rock breaking; and monitoring while drilling (WWD) methods under pure gas conditions are immature. Currently, the main media used for WWD information transmission under gas drilling conditions are electromagnetic waves and microwaves, with transmission methods including one-time transmission and relay transmission. From usage experience, due to factors such as the power of conventional battery power supply, both suffer from signal instability and limited transmission depth.

[0037] Based on this, the present invention provides a downhole electric drilling tool for gas drilling and its application method. The downhole electric drilling tool includes a drill string connector, a power unit, a transmission unit, and a drill bit. The drill string connector is fixedly connected to the upper end of the power unit and is used to connect the electric drilling tool to the upper drill string. The transmission unit and the drill bit are sequentially connected to the lower end of the power unit. The power unit includes a power supply component and a motor, which are connected to each other and provide power to the motor. The transmission unit includes a reducer connected between the motor and the drill bit, used to transmit the power output from the motor to the drill bit, driving the drill bit to drill.

[0038] This invention employs a high-density battery to directly power the electric drilling tool, and then uses a planetary reducer to obtain the torque required for gas drilling sliding drilling. This eliminates the need for a gas screw drive, significantly improving operational capability and reliability. Compared to traditional electric drilling tools, it eliminates the need for customized, complex, and expensive special drilling tools for surface power supply, as well as customized downhole generators. It can be implemented with conventional drilling tools, maximizing cost savings. The battery is installed in segments; if a battery is damaged, only the damaged segment needs to be removed for repair, while the remaining batteries can still be recharged and reused. The segmented battery installation allows for adjusting the number of battery segments based on the predicted single-trip drilling motor operating time, thereby adjusting the stored power. Due to the use of high-density batteries, it can simultaneously power the EMWD (Electromagnetic Wave Measurement While Drilling) instrument, increasing the existing electromagnetic wave transmission power by hundreds of times, thus significantly improving the operating depth of gas drilling directional and horizontal wells.

[0039] Exemplary Example 1

[0040] This exemplary embodiment provides a downhole electric drilling tool for gas drilling.

[0041] Figure 1 An overall structural cross-sectional view of a downhole electric drilling tool for gas drilling, an exemplary embodiment of the present invention, is shown. Figure 2 A cross-sectional view of the drill string joint of a downhole electric drilling tool for gas drilling, according to an exemplary embodiment of the present invention, is shown. Figure 3 A cross-sectional view of the first intermediate joint of a downhole electric drilling tool for gas drilling, an exemplary embodiment of the present invention, is shown. Figure 4 A cross-sectional view of the second intermediate joint of a downhole electric drilling tool for gas drilling, an exemplary embodiment of the present invention, is shown. Figure 5 A cross-sectional view of the battery casing of a downhole electric drilling tool for gas drilling, according to an exemplary embodiment of the present invention, is shown. Figure 6 A cross-sectional view of the reducer of a downhole electric drilling tool for gas drilling, an exemplary embodiment of the present invention, is shown.

[0042] like Figures 1 to 6As shown in the exemplary embodiment, the downhole electric drilling tool for gas drilling may include a drill string connector 1, a power unit 2, a transmission unit 3, and a drill bit 4 connected sequentially from top to bottom. The drill string connector 1 may be fixedly connected to the upper end of the power unit 2. The drill string connector 1 can be used to connect the downhole electric drilling tool to the upper drill string. Specifically, the drill string connector 1 and the power unit 2 may be threadedly connected. The transmission unit 3 and the drill bit 4 may be sequentially connected to the lower end of the power unit 2. The power unit 2 may include a power supply component 21 and a motor 22. The power supply component 21 and the motor 22 may be connected by a connecting line. The power supply component 21 can provide power to the motor 22. The transmission unit 3 may include a reducer 31. The reducer 31 may be connected between the motor 22 and the drill bit 4. It can be used to transmit the power output by the motor 22 to the drill bit 4, reduce the rotational speed and increase the torque, and drive the drill bit 4 to drill.

[0043] In this embodiment, the power assembly 21 may include a battery casing 211, a central tube 212, and a battery pack 213. The central tube 212 may be inserted into the battery casing 211, and an annular space may be formed between the outer wall of the central tube 212 and the inner wall of the battery casing 211. The battery pack 213 also has a hollow structure and can be installed in the annular space between the central tube 212 and the battery casing 211. The battery pack 213 may include at least one battery segment. Multiple grooves may be formed axially on the outer wall of the battery, and the multiple grooves may be distributed circumferentially on the outer wall of the battery. Multiple inwardly protruding fixing supports may be provided axially on the inner wall of the battery casing 211, and the multiple fixing supports may also be distributed circumferentially on the inner wall of the battery casing 211. Each groove corresponds to a fixing support and cooperates with it, which can circumferentially fix the battery in the battery casing 211 and prevent the battery from rotating in the battery casing.

[0044] Optionally, the power assembly 21 may further include a first intermediate connector 214, and the battery pack 213 may include a first battery 2131 and a second battery 2132. The first intermediate connector 214 is installed between the first battery 2131 and the second battery 2132, and the first battery 2131 and the second battery 2132 can be connected end to end to form the battery pack 213. The first intermediate connector 214 can be threadedly connected to the battery casings 211 at its upper and lower ends. A main channel 2141 and two first line channels 2142 are provided at the center of the first intermediate connector 214, wherein the main channel 2141 can be connected to... The inner cavities of the central tubes 212 connected to the upper and lower ends of the first intermediate connector 214 are connected, allowing the compressed gas introduced into the central tubes 212 to flow downward through the first intermediate connector 214; the connecting wire between the first battery 2131 and the second battery 2132 can pass through the two first line channels 2142, thereby realizing the series connection between the first battery 2131 and the second battery 2132; when the battery power is depleted and needs to be replaced, the drill string connector 1 and the power assembly 21 can be disassembled, and the first battery 2131 and the second battery 2132 can be removed from the battery casing 211 for replacement.

[0045] In this embodiment, the power supply assembly 21 may further include a second intermediate connector 215, and the second intermediate connector 215 may also have two second line channels 2151. The connecting wire between the power supply assembly 21 and the motor 22 can pass through the second line channels 2151, thereby connecting the power supply assembly 21 and the motor 22 in series, so that the motor 22 can operate under the drive of the power supply assembly 21. Specifically, the structure of the second intermediate connector 215 may be the same as or different from the structure of the first intermediate connector 214, as long as they can realize the connection function between the upper and lower components. The present invention does not make specific limitations in this regard.

[0046] Optionally, the drill string connector 1, power unit 2, transmission unit 3, and drill bit 4 can all have hollow inner cavities in their centers, such as the central flow channel 11 of the drill string connector 1, the central pipe 212 of the power unit 2 and the main flow channel 2141 of the intermediate connector, the central hole of the motor 22 and the reducer 31, and the central hole of the drill bit 4. The inner cavities of the above components can be interconnected to form a fluid channel, so that compressed gas can be input from the drill string connector 1, pass through the fluid channel, and finally be output from the drill bit 4 to the bottom of the well. This can achieve the goal of bringing out the rock cuttings generated during the drilling process of the drill bit 4 from the bottom of the well, forming a compressed gas circulation loop.

[0047] Optionally, a throttle valve (not shown in the figure) can be installed in the intermediate flow channel of motor 22 according to downhole conditions. By utilizing the heat absorption characteristics of compressed gas through throttling and depressurization, the motor can be cooled during operation, thus solving the heat generation problem.

[0048] Alternatively, the reducer 31 can be a planetary gear reducer. The upper part of the reducer 31 has two semi-circular metal locking devices in which the power output shaft of the motor 22 can be installed and locked by bolts on the side. The lower part of the reducer can be formed into a hollow convex truncated cone. The outer surface of the truncated cone can be threaded for connection with the component below.

[0049] Alternatively, the motor 22 may be an oil-filled submersible motor, and the upper part of the motor 22 may be formed into an annular groove with a central protrusion, and the protrusion may be formed into a stepped surface.

[0050] In this embodiment, the transmission unit 3 may further include a drill bit connecting shaft 32, which can be installed between the reducer 31 and the drill bit 4, and can be used to transmit torque from the reducer to the drill bit.

[0051] In this embodiment, the drill string connector 1, battery casing 211, central tube 212, first intermediate connector 214, second intermediate connector 215, motor 22, reducer 31, drill bit connecting shaft 32, and drill bit 4 can all be connected by threads. Set screws 2111 are installed on the inner walls of both ends of the battery casing 211. Seals can be installed at the connection points between the above-mentioned components. For example, seals 311 are installed at each connection point in the reducer 31. Specifically, the seals can be rubber sealing rings, which can seal the connection points between the components to prevent external impurities from entering the drill bit and internal compressed gas from leaking out.

[0052] The working process of the downhole electric drilling tool for gas drilling described in this exemplary embodiment is described in detail below:

[0053] First, the entire electric drill is assembled. The first battery 2131 and the second battery 2132 are connected in series with a connecting wire. Electricity reaches the motor 22 through the first line channel 2142 of the first intermediate connector 214, driving the output shaft of the motor 22 to rotate. The output shaft of the motor 22 drives the reducer 31 through the connector on the upper part of the reducer 31. The output shaft of the reducer 31 drives the drill bit connecting shaft 32 to rotate, thereby driving the drill bit 4 to rotate. Compressed gas originates from a gas compressor on the ground, passes through the drill string, and reaches the electric drill. It then sequentially passes through the central flow channel 11 of the drill string connector 1, the central pipe 212, the main flow channel 2141 of the first intermediate connector 214, the intermediate flow channel of the motor rotor of the motor 22, the intermediate flow channel of the reducer 31, and the intermediate flow channel of the drill bit connecting shaft 32, finally reaching the drill bit 4. While the drill bit 4 cuts the rock, the compressed gas carries the rock cuttings generated during drilling away from the bottom of the well.

[0054] Because the battery section of the electric drill uses a segmented design (i.e., the first battery 2131 and the second battery 2132), if the battery pack 213 is damaged, it needs to be repaired or replaced. Simply remove the damaged battery and replace it with a new one, and the entire electric drill will still function normally.

[0055] Exemplary Example 2

[0056] This exemplary embodiment provides a method for applying a downhole electric drilling tool for gas drilling in drilling operations.

[0057] The application method can be implemented by using the downhole electric drilling tool for gas drilling as described in Exemplary Example 1.

[0058] The application method may include:

[0059] First, assemble the entire electric drilling tool. Connect the first and second batteries in series with connecting wires. Connect the drill string connector to the upper drill pipe. Lower the drill pipe along the wellhead to lower the downhole electric drilling tool to the designated position in the well. Control the start motor. Electricity reaches the motor through the first line channel of the first intermediate connector, driving the motor's output shaft to rotate. The motor's output shaft drives the reducer through the connector on the upper part of the reducer. The reducer's output shaft drives the drill bit connecting shaft to rotate, thereby driving the drill bit to perform drilling operations. Compressed gas originates from a gas compressor on the surface, passes through the drill string, and reaches the electric drilling tool. It then sequentially passes through the central flow channel of the drill string connector, the central pipe, the main flow channel of the first intermediate connector, the intermediate flow channel of the motor rotor, the intermediate flow channel of the reducer, and the intermediate flow channel of the drill bit connecting shaft, finally reaching the drill bit. While the drill bit cuts the rock, the compressed gas carries the rock cuttings generated during drilling away from the bottom of the well.

[0060] This invention employs a high-density battery to directly power the electric drilling tool, and then uses a planetary reducer to obtain the torque required for gas drilling sliding drilling. This eliminates the need for a gas screw drive, significantly improving operational capability and reliability. Compared to traditional electric drilling tools, it eliminates the need for customized, complex, and expensive special drilling tools for surface power supply, as well as customized downhole generators. It can be implemented with conventional drilling tools, maximizing cost savings. The battery is installed in segments; if a battery is damaged, only the damaged segment needs to be removed for repair, while the remaining batteries can still be recharged and reused. The segmented battery installation allows for adjusting the number of battery segments based on the predicted single-trip drilling motor operating time, thereby adjusting the stored power. Due to the use of high-density batteries, it can simultaneously power the EMWD (Electromagnetic Wave Measurement While Drilling) instrument, increasing the existing electromagnetic wave transmission power by hundreds of times, thus significantly improving the operating depth of gas drilling directional and horizontal wells.

[0061] Although the present invention has been described above in conjunction with exemplary embodiments and accompanying drawings, those skilled in the art should understand that various modifications can be made to the above embodiments without departing from the spirit and scope of the claims.

Claims

1. A downhole electric drilling tool for gas drilling, characterized in that, The downhole electric drilling tool includes a drill string connector, a power unit, a transmission unit, and a drill bit, wherein, The drill string connector is fixedly connected to the upper end of the power unit, and is used to connect the electric drill to the upper drill string; The transmission unit and the drill bit are connected in sequence to the lower end of the power unit. The power unit includes a power supply component and a motor. The power supply component is connected to the motor and can provide power to the motor. The transmission unit includes a reducer, which is connected between the motor and the drill bit to transmit the power output by the motor to the drill bit, thereby driving the drill bit to drill. The power assembly includes a battery casing, a central tube, and a battery pack. The central tube passes through the battery casing, and an annular space is formed between the outer wall of the central tube and the inner wall of the battery casing. The battery pack is disposed in the annular space. The battery pack includes at least one battery segment. The outer wall of the battery has several grooves along the axial direction, and the inner wall of the battery casing has several inwardly protruding fixing supports along the axial direction. The grooves and fixing supports correspond one-to-one and cooperate with each other to fix the battery circumferentially in the battery casing. The power assembly further includes a first intermediate connector. The battery pack includes a first battery and a second battery. The first intermediate connector is disposed between the first battery and the second battery. The first intermediate connector connects the first battery and the second battery end to end to form the battery pack. A main channel is opened at the center of the first intermediate connector. The main channel is connected to the inner cavity of the central tube. At least one first line channel is also opened on the first intermediate connector. The first battery and the second battery can be connected in series through a connecting wire passing through the first line channel.

2. The downhole electric drilling tool for gas drilling according to claim 1, characterized in that, A second intermediate connector is installed between the power supply component and the motor. The second intermediate connector has at least one second line channel, and the power supply component and the motor can be connected in series through a connecting wire passing through the second line channel.

3. The downhole electric drilling tool for gas drilling according to claim 1, characterized in that, The inner cavity of the drill string joint, the inner cavity at the center of the power unit, the inner cavity of the transmission unit, and the inner cavity of the drill bit are interconnected to form a fluid channel, so that compressed gas can pass through it.

4. The downhole electric drilling tool for gas drilling according to claim 1, characterized in that, A throttle valve can be installed inside the motor according to downhole conditions. Compressed gas can be throttled and depressurized through the throttle valve to cool the motor.

5. The downhole electric drilling tool for gas drilling according to claim 1, characterized in that, The motor is an oil-filled submersible motor, and the reducer is a planetary gear reducer.

6. The downhole electric drilling tool for gas drilling according to claim 1, characterized in that, The drill string connector is threadedly connected to the battery casing, the drill string connector is threadedly connected to the central tube, the battery casing is threadedly connected to the first intermediate connector, and the central tube is threadedly connected to the first intermediate connector. Set screws are installed at both ends of the inner wall of the battery casing. Sealing elements are installed between the drill string connector and the battery casing, between the drill string connector and the central tube, between the battery casing and the first intermediate connector, and between the central tube and the first intermediate connector to seal each connection point.

7. The downhole electric drilling tool for gas drilling according to claim 1, characterized in that, The transmission unit also includes a drill bit connecting shaft, which is installed between the reducer and the drill bit to transmit torque from the reducer to the drill bit.

8. A method for applying a downhole electric drilling tool for gas drilling in drilling operations, characterized in that, The application method employs a downhole electric drilling tool for gas drilling as described in any one of claims 1 to 7. The application method includes connecting the drill string joint to the upper drill pipe, lowering the drill pipe along the wellhead to lower the downhole electric drilling tool to a designated position downhole, controlling the start of the motor, transmitting power to the drill bit through the reducer to drive the drill bit to perform drilling operations, and inputting compressed gas into the drill bit through the inner cavity of the drill string joint, the inner cavity of the power unit, and the inner cavity of the transmission unit to carry away the rock cuttings generated by the drill bit from the bottom of the well.

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