Deflection device for ultra-short radius well sidetracking

Abstract

A deflection device for ultra-short radius well sidetracking. The device comprises a flexible drill pipe, wherein a central flow channel is provided inside the flexible drill pipe; a drill bit (1) is connected to the lower end of the flexible drill pipe; a mud flow-through hole (2) in communication with the central flow channel is provided at an end of the drill bit (1); a sealed chamber is fixed in the central flow channel close to the drill bit; a well deflection data acquisition unit and a pressure pulse generation unit are provided in the sealed chamber; the well deflection data acquisition unit is configured to acquire well deflection data in a deflection process, so as to obtain a control pulse on the basis of the well deflection data; and the pressure pulse generation unit is configured to adjust, on the basis of the control pulse, the flow rate of mud passing through the mud flow-through hole, so as to generate a corresponding mud pressure pulse, such that the ground receives the mud pressure pulse and then decodes same to obtain deflection information.

Description

Ultra-short radius side drilling deflection device

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to the Chinese patent application filed with the China Patent Office on November 16, 2023, with application number 202311531656.1 and titled “Ultra-short radius side drilling inclination device”, the entire contents of which are incorporated by reference into this application. Technical Field

[0003] The present disclosure belongs to the technical field of ultra-short radius drilling, and in particular relates to an ultra-short radius sidetracking and deflecting device. Background Art

[0004] By side-drilling horizontal wells in old wells, the remaining oil-rich areas can be directly exploited, and unused reservoirs can also be exploited. This has the advantages of low cost, high production efficiency, and can effectively improve the recovery rate.

[0005] However, while sidetracking utilizes the existing wellbore to drill the target area, it also causes damage to the casing. Existing methods often use coiled tubing to sidetrack horizontal wells. This creates a deflection section that can be tens or even hundreds of meters long, resulting in poor turning capabilities, extensive casing damage, and difficulty in repair. To overcome these drawbacks, the ultra-short radius drilling method has been proposed.

[0006] The sidetracking operation process includes window opening, window repair, deflection and horizontal drilling. Among the above processes, the deflection process is closely related to the wellbore trajectory. On the basis of window opening and window repair, it is necessary to transition the wellbore trajectory from a nearly vertical state to a horizontal state. Therefore, real-time understanding and control of the deflection situation is an urgently needed technology. Summary of the Invention

[0007] In order to solve all or part of the above problems, the present disclosure aims to provide an ultra-short radius side drilling inclination device, which can understand the inclination situation in real time through the setting of a well inclination data acquisition unit and a pressure pulse generating unit.

[0008] According to one aspect of the present disclosure, an ultra-short radius sidetracking device is provided, comprising a flexible drill pipe composed of a plurality of flexible pup joints, a central flow channel being provided inside the flexible drill pipe, a drill bit being connected to the lower end of the flexible drill pipe, and a mud flow hole being provided at the end of the drill bit and communicating with the central flow channel;

[0009] A sealed cavity is fixed in the central flow channel near the drill bit, and a well inclination data acquisition unit and a pressure pulse generating unit are provided in the sealed cavity. The well inclination data acquisition unit is used to acquire the well inclination data during the inclination process so as to obtain a control pulse based on the well inclination data. The pressure pulse generating unit is used to adjust the mud flow through the mud flow hole based on the control pulse to generate a corresponding mud pressure pulse so that the ground can receive the mud pressure pulse and decode the inclination information.

[0010] Furthermore, the well deviation data acquisition unit is a three-axis acceleration sensor assembly arranged in the sealed cavity, and the three-axis acceleration sensor assembly is composed of three acceleration sensors.

[0011] Furthermore, the pressure pulse generating unit includes a battery pack, a drive motor and a control circuit arranged in a sealed cavity. The battery pack is used to power the control circuit, and the control circuit is used to control the drive motor. The lower end of the motor shaft of the drive motor extends out of the sealed cavity and is fixedly connected to the gear disc. A throttle cylinder is fixedly connected to the drill bit, and a plurality of mud holes are opened on the bottom of the throttle cylinder. The gear disc is located in the throttle cylinder and contacts with the bottom of the throttle cylinder. The rotation of the drive motor can drive the gear disc to cover the mud hole, or drive the gear disc not to cover the mud hole.

[0012] Furthermore, several mud holes are evenly distributed on the throttle cylinder, the gear disc includes an annular block and a blocking block fixed on the outer circumference of the annular block, the blocking block can block the mud holes, the annular block is fixed on the motor shaft of the drive motor, the number of blocking blocks is equal to the number of mud holes, and the blocking blocks are evenly arranged.

[0013] Furthermore, an arc-shaped groove is provided on the gear disc, and a limit pin is fixedly connected to the bottom of the throttle cylinder. The limit pin is located in the arc-shaped groove. The limit pin is used to limit the extreme rotation angle of the gear disc from one extreme position to another extreme position, and when the gear disc rotates to one of the extreme positions, the blocking area of ​​the mud hole by the gear disc is the largest, and when the gear disc rotates to the other extreme position, the gear disc does not block the mud hole.

[0014] Furthermore, the maximum rotation angle of the toothed disc is 45 degrees, and the maximum blocking area of ​​the mud hole by the toothed disc is 20% of the maximum flow area of ​​the mud hole; a reduction unit is provided in the sealing cavity, the drive motor is connected to the reduction unit, and the output shaft of the reduction unit is connected to the toothed disc through a connecting pin; the number of mud flow holes is equal to the number of mud holes, and each mud hole is opposite to a mud flow hole.

[0015] Furthermore, the control circuit includes a first transistor, a second transistor, a first relay, and a second relay, wherein the first transistor is turned on to energize the coil of the first relay, and the second transistor is turned on to energize the coil of the second relay;

[0016] The first relay has two contacts: a first relay contact 1 and a first relay contact 2; the second relay has two contacts: a second relay contact 1 and a second relay contact 2;

[0017] The C fixed end of the first relay contact is connected to the B movable end of the second relay contact and the A movable end of the second relay contact. The A movable end of the first relay contact is connected to the positive electrode of the battery pack, and the B movable end of the first relay contact is suspended.

[0018] The C fixed end of the first relay contact 2 is connected to the A movable end of the second relay contact 1 and the B movable end of the second relay contact 2, the A movable end of the first relay contact 2 is connected to the negative electrode of the battery pack, and the B movable end of the first relay contact 2 is suspended;

[0019] The C fixed end of the second relay contact 1 is connected to the + pin of the drive motor, and the C fixed end of the second relay contact 2 is connected to the - pin of the drive motor;

[0020] The coil of the first relay is energized to connect the C fixed end of the first relay contact 1 with the A movable end of the first relay contact 1, and to connect the C fixed end of the first relay contact 2 with the A movable end of the first relay contact 2;

[0021] The coil of the second relay is energized to connect the C fixed end of the second relay contact 1 with the A movable end of the second relay contact 1, and to connect the C fixed end of the second relay contact 2 with the A movable end of the second relay contact 2.

[0022] Furthermore, each flexible short section includes a ball head, the upper end of each ball head is connected to an outer shell through a torque pin, the uppermost outer shell is fixedly connected to the upper joint, the lower end of the lowermost ball head is fixedly connected to the lower joint, the lower joint is fixedly connected to the drill bit, and the lower end of each of the remaining ball heads is fixedly connected to a connecting sleeve, each connecting sleeve is fixedly connected to the outer shell below it, and a gap is provided between each torque pin and the ball head, between the lowermost outer shell and the lower joint, and between each of the remaining outer shells and the connecting sleeves below it to allow the flexible drill rod to bend.

[0023] Furthermore, the sealing cavity is arranged in the space formed by the lowermost ball head, the lower joint and the drill bit.

[0024] Furthermore, the sealed cavity includes a measurement and control shell, which is fixed in the central flow channel near the drill bit, and the upper end of the measurement and control shell is sealed and connected with a connecting structure; the connecting structure is a connecting nut, and a sealing ring is provided between the connecting nut and the measurement and control shell, and a wrench hole is provided on the side of the connecting nut away from the measurement and control shell.

[0025] Furthermore, the outer sleeve of the measurement and control shell is provided with an upper centralizing plate and a lower centralizing plate, both of which are provided with through holes for mud to pass through; the lower centralizing plate is limited between the lower joint and the drill bit, and the lower centralizing plate is fixedly connected to the measurement and control shell.

[0026] Furthermore, the drill bit is provided with axial cutting teeth and lateral cutting teeth. The axial cutting teeth are evenly distributed at the lower end of the drill bit, and the lateral cutting teeth are used to generate side cutting force.

[0027] As can be seen from the above technical solutions, the ultra-short radius sidetracking device provided by the present disclosure has the following beneficial effects:

[0028] The ultra-short radius side drilling inclination device disclosed herein achieves the purpose of obtaining inclination data in real time by arranging a well inclination data acquisition unit and a pressure pulse generation unit in a limited space, making it easier to understand and grasp the inclination situation in real time.

[0029] Summary of the Figures

[0030] Figure 1 is a schematic diagram of the relationship between the flexible nipple and the curved pipe;

[0031] FIG2 is a cross-sectional view of an ultra-short radius sidetracking and deflecting device according to an embodiment of the present disclosure;

[0032] Figure 3 is a schematic diagram of the toothed disc when it does not block the mud hole;

[0033] Figure 4 is a schematic diagram of the toothed disc shielding the mud hole;

[0034] FIG5 is a schematic diagram of a control circuit according to an embodiment of the present disclosure (the drive motor is not rotating at this time);

[0035] FIG6 is a schematic diagram of a control circuit according to an embodiment of the present disclosure (the drive motor rotates in one direction at this time);

[0036] FIG7 is a schematic diagram of a control circuit according to an embodiment of the present disclosure (the drive motor rotates in the other direction at this time);

[0037] The accompanying drawings are marked as follows: drill bit 1, mud flow hole 2, lateral cutting teeth 3, throttle cylinder 4, mud hole 5, toothed disc 6, lower straightening plate 7, battery pack 8, measurement and control shell 9, reduction unit 10, stop pin 11, drive motor 12, three-axis acceleration sensor assembly 13, control circuit 14, connecting nut 15, sealing ring 16, wrench hole 17, axial cutting teeth 18, connecting sleeve 19, ball head 20, lower joint 21, upper straightening plate 22, upper joint 23, outer sleeve 24, spring retaining ring 25, torque pin 26, sealing ring 27, connecting pin 28, limit pin 29, arc groove 30.

[0038] Preferred embodiments of the present disclosure

[0039] In order to better understand the purpose, structure and function of the present invention, an ultra-short radius side drilling and deflection device of the present invention is further described in detail below with reference to the accompanying drawings.

[0040] The ultra-short radius of the embodiment disclosed herein refers to a deflection curvature radius of 1.25m-3.6m. In the prior art, there are very few side drilling tools with this curvature radius, and no pressure pulse generator related thereto has been reported. Drilling tools suitable for this curvature radius require the use of special flexible drill pipes. For example, the curvature radius R1 of the curved pipe in the deflection section is 1.25m, the inner diameter d1 of the curved pipe is 152.5mm, and the maximum diameter of the flexible short section is 144mm. As shown in FIG1 , the midpoint gap Δ between the curved pipe and the single section of flexible drill pipe can be obtained: Δ=d1-d2=152.5mm-144mm=8.5mm,

[0041] Based on this, the maximum length L1 of the flexible short section that can pass through the curved pipe can be obtained:

[0042] Substituting these values ​​into the calculation, we find that L1 equals 300 mm. This means that the maximum length of a flexible sub capable of navigating a curved pipe with a curvature radius R1 of 1.25 m and an inner diameter d1 of 152.5 mm is 300 mm. However, within this 300 mm length, it is difficult to arrange the pulse generator and inclination measurement components, making it impossible to obtain real-time inclination information during the inclination process.

[0043] In order to overcome the shortcomings of the prior art that the pulse generator and the well inclination measuring component cannot be arranged within a shorter limit length range, the embodiment of the present disclosure proposes an ultra-short radius side drilling well inclination device, as shown in Figure 2, the inclination device includes a flexible drill pipe composed of a number of flexible short sections, a central flow channel is arranged inside the flexible drill pipe, the lower end of the flexible drill pipe is connected to the drill bit 1, and the end of the drill bit 1 is provided with a mud flow hole 2 connected to the central flow channel; a sealed cavity is fixed in the central flow channel near the drill bit 1, and a well inclination data acquisition unit and a pressure pulse generating unit are provided in the sealed cavity, wherein the well inclination data acquisition unit is used to acquire the well inclination data during the inclination process so as to obtain a control pulse based on the well inclination data, and the pressure pulse generating unit is used to adjust the mud flow through the mud flow hole 2 based on the control pulse to generate a corresponding mud pressure pulse, so that the ground can receive the mud pressure pulse and decode the inclination information.

[0044] Specifically, the embodiment of the present disclosure utilizes the inflexible space at the lower end of the inclination device near the drill bit 1, and sets a well inclination data acquisition unit and a pressure pulse generation unit in this space to obtain real-time inclination data during the inclination process.

[0045] Among them, the well inclination data acquisition unit is used to obtain the well inclination data during the inclination process, so as to obtain the control pulse according to the well inclination data. The pressure pulse generating unit is used to adjust the mud flow through the mud flow hole 2 according to the control pulse to generate the corresponding mud pressure pulse. After the ground receives the mud pressure pulse, the inclination information can be decoded, thereby achieving the purpose of measuring inclination at the drill bit 1 and timely guiding the front trajectory during the inclination process.

[0046] Through the configuration of the embodiment of the present disclosure, the purpose of obtaining the deflection data in real time is achieved, which facilitates real-time understanding and control of the deflection situation.

[0047] In a specific embodiment, the well deviation data acquisition unit is a three-axis acceleration sensor assembly 13 disposed in a sealed cavity. The three-axis acceleration sensor assembly 13 is composed of three acceleration sensors.

[0048] In view of the characteristics of ultra-short radius inclination, the embodiment of the present disclosure omits components such as the flux gate and adopts a three-axis acceleration sensor assembly 13 to measure well inclination, thereby reducing the volume and achieving the purpose of measuring well inclination at the drill bit 1, thereby timely guiding the front trajectory during the inclination process based on the measured well inclination.

[0049] Specifically, the acceleration sensor of this embodiment is a microgravity accelerometer, which can reflect tiny changes in gravity and has a resolution of μg. For example, the HQA-T 185S acceleration sensor is used. Since the sidetracking direction is determined before drilling and positioned by the sidetracking tool, it is only necessary to measure the well inclination to understand the inclination situation. The well inclination angle DEV can be obtained by the gravity acceleration gx, gy, and gz in the X, Y, and Z directions of the three-axis accelerometer, that is,

[0050] Again, the signal output by the acceleration sensor can be an analog signal or a digital signal. For analog signals, they are processed by the pulse generating circuit after digital-to-analog conversion to generate a related pulse signal. For digital signals, the pulse generating circuit directly generates a related pulse signal, which is the control pulse.

[0051] Specifically, the method for deriving control pulses from acceleration sensor signals involves converting the acceleration measured by the sensor in the X, Y, and Z directions into binary codes. For example, the decimal number "185" is converted to binary code "10111001." To achieve measurement accuracy and resolution expressed in μg, the measured data is amplified several times beforehand and still represented in binary form. For example, 185.4321 multiplied by 10,000 becomes 1854321, corresponding to the binary code "111000100101101110001." The accelerations in the X, Y, and Z directions are processed in the same manner, sequentially generating an 8-bit binary code. A "1" in the binary code indicates a pressure pulse, and a "0" indicates no pulse. Each bit is generated at a specific time interval, for example, 0.1 seconds. For a binary code of 1001, the first 0.1 second generates a pressure pulse, the second and third 0.1 seconds do not, and the fourth 0.1 second generates a pressure pulse. Thus, the purpose of obtaining control pulses based on well deviation data is achieved.

[0052] In a specific embodiment, the pressure pulse generating unit includes a battery pack 8, a drive motor 12 and a control circuit 14 arranged in a sealed cavity. The battery pack 8 is used to power the control circuit 14, and the control circuit 14 is used to control the drive motor 12. The lower end of the motor shaft of the drive motor 12 extends out of the sealed cavity and is fixedly connected to the gear disc 6. A throttle cylinder 4 is fixedly connected to the drill bit 1, and a plurality of mud holes 5 are opened on the bottom of the throttle cylinder 4. The gear disc 6 is located in the throttle cylinder 4 and contacts the bottom of the throttle cylinder 4. The rotation of the drive motor 12 can drive the gear disc 6 to block the mud hole 5, or drive the gear disc 6 not to block the mud hole 5.

[0053] In this embodiment, the pressure pulse generating unit includes a battery pack 8, a drive motor 12, and a control circuit 14. The battery pack 8 is used to power the control circuit 14 or other electrical devices, and the control circuit 14 is used to control the drive motor 12 according to the control pulses. The lower end of the motor shaft of the drive motor 12 extends outside the sealed cavity, and the gear disc 6 is disposed below the sealed cavity. After the motor shaft of the drive motor 12 extends out of the sealed cavity, it is fixedly connected to the gear disc 6, thereby controlling the gear disc 6 through the drive motor 12.

[0054] Specifically, a mounting hole is provided at one end of the drill bit 1 near the flexible drill rod, and a throttle barrel 4 is disposed within the mounting hole. The throttle barrel 4 and the drill bit 1 are connected by a stop pin 11, thereby preventing the throttle barrel 4 from rotating. A plurality of mud holes 5 are provided on the bottom wall of the throttle barrel 4. A gear disc 6 is located within the throttle barrel 4 and contacts the bottom wall of the throttle barrel 4. As the drive motor 12 rotates, the gear disc 6 rotates accordingly. When the gear disc 6 rotates, the throttle barrel 4 does not rotate, thereby achieving the purpose of the gear disc 6 covering the mud holes 5 or not covering the mud holes 5. When the gear disc 6 covers the mud holes 5, the pressure of the mud flowing through the mud holes 5 increases, generating a corresponding mud pressure pulse. When the gear disc 6 does not cover the mud holes 5, the pressure of the mud flowing through the mud holes 5 remains unchanged, and therefore no mud pressure pulse is generated.

[0055] The disclosed embodiment utilizes a micro-drive motor 12-driven toothed disc 6 to directly regulate the mud flow through the mud flow holes 2 of the drill bit 1, making it suitable for generating mud pulses in ultra-short radius sidetracking. The coordination of the drive motor 12, toothed disc 6, and throttle barrel 4 enables the generation or elimination of mud pressure pulses.

[0056] In specific implementation, the blocked area should be smaller than the maximum flow area of ​​the mud hole 5, that is, the toothed disc 6 blocks part of the flow area of ​​the mud hole 5, so as to ensure the safety of the drilling process, for example, the toothed disc 6 blocks at most 20% of the flow area of ​​the mud hole.

[0057] Secondly, a reduction unit 10 can also be disposed within the sealed cavity. The input shaft of the reduction unit 10 is connected to the motor shaft of the drive motor 12, and the output shaft of the reduction unit 10 is connected to the gear wheel 6 via a connecting pin 28. Thus, the reduction unit 10 reduces the speed of the drive motor 12 and increases the torque. That is, the battery pack 8, the triaxial acceleration sensor assembly 13, the control circuit 14, the drive motor 12, and the reduction unit 10 are disposed within the sealed cavity in order from left to right.

[0058] Finally, in order to allow the pressurized mud passing through the mud holes 5 to flow directly out of the mud flow holes 2 on the drill bit 1, the number of mud flow holes 2 should be equal to the number of mud holes 5, and each mud hole 5 should face a mud flow hole 2.

[0059] In a specific embodiment, as shown in Figures 3-4, several mud holes 5 are evenly distributed on the throttle cylinder 4, and the gear disk 6 includes an annular block and a blocking block fixed on the outer circumference of the annular block. The blocking block can block the mud hole 5. The annular block is fixed on the motor shaft of the drive motor 12. The number of blocking blocks is equal to the number of mud holes, and the blocking blocks are evenly arranged.

[0060] Specifically, as shown in Figures 3 and 4, a plurality of mud holes 5 are evenly distributed on the throttle cylinder 4. In a specific implementation, for example, the number of mud holes 5 is four. The gear disc 6 includes an annular block and a blocking block. The annular block is fixedly connected to the motor shaft of the drive motor 12, and the blocking block is fixed to the outer circumference of the annular block. The blocking block and the annular block can be an integrally formed structure or a fixed structure fixedly connected together.

[0061] Again, the number of shielding blocks is equal to the number of mud holes 5, and the shielding blocks are evenly arranged. For example, as shown in FIG3-4 , the number of shielding blocks is 4, and they are evenly distributed on the outer circumference of the annular block.

[0062] In a specific embodiment, as shown in Figures 3-4, an arc-shaped groove 30 is provided on the toothed disc 6, and a limit pin 29 is fixedly connected to the bottom of the throttle cylinder 4. The limit pin 29 is located in the arc-shaped groove 30. The limit pin 29 is used to limit the extreme rotation angle of the toothed disc 6 from one extreme position to another extreme position, and when the toothed disc 6 rotates to one of the extreme positions, the blocking area of ​​the mud hole 5 by the toothed disc 6 is the largest. When the toothed disc 6 rotates to the other extreme position, the toothed disc 6 does not block the mud hole 5.

[0063] This embodiment limits the rotation angle of the toothed disc 6 through the cooperation of the arcuate groove 30 and the limit pin 29. Specifically, the arcuate groove 30 is provided on the toothed disc 6, and the limit pin 29 is fixedly connected to the bottom of the throttle barrel 4, with the limit pin 29 extending into the arcuate groove 30. Alternatively, the arcuate groove 30 can be provided on the bottom of the throttle barrel 4, and the limit pin 29 can be fixedly connected to the toothed disc 6, with the limit pin 29 similarly extending into the arcuate groove 30.

[0064] In this embodiment, when the toothed disc 6 is in one of its extreme positions, the area blocked by the toothed disc 6 blocking the mud hole 5 is maximized, the pressure of the mud passing through is maximized, and a mud pressure pulse is generated. When the toothed disc 6 rotates to the other extreme position, the toothed disc 6 no longer blocks the mud hole 5, thereby facilitating adjustment of the toothed disc 6. Specifically, when it is desired to generate a mud pressure pulse, the drive motor 12 controls the toothed disc 6 to rotate to the extreme position blocking the mud hole 5. When it is not desired to generate a mud pressure pulse, the drive motor 12 controls the toothed disc 6 to rotate to the extreme position not blocking the mud hole 5.

[0065] Specifically, when the toothed disc 6 is in the extreme position shown in FIG3 , the toothed disc 6 does not block the mud hole 5. When the toothed disc 6 rotates from the extreme position shown in FIG3 to the extreme position shown in FIG4 , the toothed disc 6 begins to block the mud hole 5, and the blocking area of ​​the mud hole 5 by the toothed disc 6 gradually increases until the designed maximum blocking area is reached. When the maximum blocking area is reached, the toothed disc 6 rotates to the extreme position shown in FIG4 . In a specific implementation, for example, the extreme rotation angle of the toothed disc 6 is 45 degrees, and the maximum blocking area of ​​the mud hole 5 by the toothed disc 6 is 20% of the maximum flow area of ​​the mud hole 5.

[0066] In a specific embodiment, as shown in Figures 5, 6, and 7, the control circuit 14 includes a first transistor T1, a second transistor T2, a first relay KA1, and a second relay KA2, wherein the first transistor T1 is turned on to energize the coil of the first relay KA1, and the second transistor T2 is turned on to energize the coil of the second relay KA2.

[0067] The first relay KA1 has two contacts: the first relay contact KA1-1 and the first relay contact KA1-2; the second relay KA2 has two contacts: the second relay contact KA2-1 and the second relay contact KA2-2; the C fixed end of the first relay contact KA1-1 is connected to the B active end of the second relay contact KA2-1 and the A active end of the second relay contact KA2-2, the A active end of the first relay contact KA1-1 is connected to the positive electrode of the battery pack, and the first relay contact The B active end of KA1-1 is suspended; the C fixed end of the first relay contact KA1-2 is connected to the A active end of the second relay contact KA2-1 and the B active end of the second relay contact KA2-2, the A active end of the first relay contact KA1-2 is connected to the negative pole of the battery pack, and the B active end of the first relay contact KA1-2 is suspended; the C fixed end of the second relay contact KA2-1 is connected to the + pin of the drive motor, and the C fixed end of the second relay contact KA2-2 is connected to the - pin of the drive motor.

[0068] The coil of the first relay KA1 is energized to connect the C fixed end of the first relay contact KA1-1 with the A movable end of the first relay contact KA1-1, and to connect the C fixed end of the first relay contact KA1-2 with the A movable end of the first relay contact KA1-2; the coil of the second relay KA2 is energized to connect the C fixed end of the second relay contact KA2-1 with the A movable end of the second relay contact KA2-1, and to connect the C fixed end of the second relay contact KA2-2 with the A movable end of the second relay contact KA2-2.

[0069] The control circuit 14 of this embodiment realizes the forward rotation of the drive motor 12 , the reverse rotation of the drive motor 12 , and the stopping of the drive motor 12 .

[0070] Specifically, referring to Figure 5, after the gear disc 6 moves to the extreme position, the drive motor 12 stops rotating: the first transistor T1 and the second transistor T2 are both non-conductive, and at this time, the C fixed end of the first relay contact KA1-1 is connected to the floating end (that is, the B active end) of the first relay contact KA1-1, and the C fixed end of the first relay contact KA1-2 is connected to the floating end (that is, the B active end) of the first relay contact KA1-2, so the positive and negative poles of the battery pack are not connected to the circuit, and the electric energy cannot be transmitted to the + and - pins of the drive motor 12, so the drive motor 12 stops rotating and the gear disc 6 does not rotate; thereby, it can prevent the drive motor 12 from continuing to rotate and consuming the energy of the battery pack after the gear disc 6 rotates to the extreme position.

[0071] Referring to Figure 6, after the transistor T1 is turned on under the action of the control circuit, the current on the collector c of the transistor T1 flows through the coil of the first relay KA1, and the coil works to connect the C fixed end of the first relay contact KA1-1 with the A active end of the first relay contact KA1-1, and to connect the C fixed end of the first relay contact KA1-2 with the A active end of the first relay contact KA1-2. At this time, the positive and negative poles of the battery pack are both connected to the circuit, and the positive pole of the battery pack is connected to the + pin of the drive motor 12 after passing through the circuit, and the negative pole of the battery pack is connected to the - pin of the drive motor 12 after passing through the circuit, thereby realizing the forward rotation of the drive motor 12, driving the gear wheel 6 to rotate in one direction.

[0072] Referring to FIG7 , after both transistors T1 and T2 are turned on by the control circuit, the current on the collector electrode c of transistor T1 flows through the coil of the first relay KA1, and the coil operates to connect the C fixed terminal of the first relay contact KA1-1 to the A movable terminal of the first relay contact KA1-1, and to connect the C fixed terminal of the first relay contact KA1-2 to the A movable terminal of the first relay contact KA1-2; the current on the collector electrode c of transistor T2 flows through the coil of the second relay KA2, and the coil operates. The C fixed end of the second relay contact KA2-1 is connected to the A movable end of the second relay contact KA2-1, and the C fixed end of the second relay contact KA2-2 is connected to the A movable end of the second relay contact KA2-2; at this time, the positive and negative poles of the battery pack are both connected to the circuit, and the positive pole of the battery pack is connected to the - pin of the drive motor 12 after passing through the circuit, and the negative pole of the battery pack is connected to the + pin of the drive motor 12 after passing through the circuit, thereby realizing the reversal of the drive motor 12 and driving the gear wheel 6 to rotate in another direction.

[0073] In a specific embodiment, each flexible short section includes a ball head 20, the upper end of each ball head 20 is connected to an outer shell 24 through a torque pin 26, the uppermost outer shell 24 is fixedly connected to the upper joint 23, the lower end of the lowermost ball head 20 is fixedly connected to the lower joint 21, the lower joint 21 is fixedly connected to the drill bit 1, and the lower end of each of the remaining ball heads 20 is fixedly connected to a connecting sleeve 19, and each connecting sleeve 19 is fixedly connected to the outer shell 24 below it. A gap is provided between each torque pin 26 and the ball head 20, between the lowermost outer shell 24 and the lower joint 21, and between each of the remaining outer shells 24 and the connecting sleeve 19 below it to allow the flexible drill rod to bend.

[0074] In this embodiment, each flexible sub includes a ball head 20, the upper end of each ball head 20 is connected to the outer casing 24 via a torque pin 26, and the torque pin 26 is clamped on the outer casing 24 via a spring collar 25; except for the bottom ball head 20, the lower end of each of the other ball heads 20 is fixedly connected to a connecting sleeve 19; each connecting sleeve 19 is fixedly connected to the outer casing 24 below it; the top outer casing 24 is fixedly connected to the upper joint 23, and the bottom ball head 20 is fixedly connected to the lower joint 21, thereby achieving the purpose of connecting the flexible drill pipe to the drill bit 1 through the lower joint 21 and achieving the purpose of connecting the flexible drill pipe to other pipe strings through the upper joint 23. The fixed connection of this embodiment can be achieved by a threaded connection in specific implementation.

[0075] Secondly, to enable the flexible drill rod to bend, in this embodiment, gaps are provided between each torque pin 26 and the ball head 20, between the lowest outer shell 24 and the lower joint 21, and between each of the remaining outer shells 24 and the connecting sleeve 19 below them to allow the flexible drill rod to bend. Taking the first ball head 20 as an example, the gap between the torque pin 26 and the ball head 20 allows the upper joint 23 and the outer shell 24 on the ball head 20 to bend relative to the ball head 20. The gap between the outer shell 24 and the connecting sleeve 19 provides clearance for the outer shell 24 to bend, making the outer shell 24 and the upper joint 23 bendable. Similarly, the gap between the lowest outer shell 24 and the lower joint 21 also provides clearance for the lowest outer shell 24 to bend.

[0076] Finally, a sealing ring 27 is provided between each connecting sleeve 19 and the ball head 20 below it, and between the uppermost ball head 20 and the upper joint 23 .

[0077] In a specific embodiment, the sealed cavity is disposed in a space formed by the lowermost ball head 20 , the lower joint 21 and the drill bit 1 .

[0078] Specifically, the lowest ball head 20 is fixedly connected to the lower joint 21, and the lower joint 21 is fixedly connected to the drill bit. Therefore, the space between the lowest ball head 20, the lower joint 21 and the drill bit 1 is a space that cannot be bent, and the sealed cavity in this embodiment is arranged in this space.

[0079] In a specific embodiment, the sealed cavity includes a measurement and control shell 9, which is fixed in the central flow channel near the drill bit 1, and the upper end of the measurement and control shell 9 is sealed and connected with a connecting structure; the connecting structure is a connecting nut 15, and a sealing ring 16 is provided between the connecting nut 15 and the measurement and control shell 9, and a wrench hole 17 is provided on the side of the connecting nut 15 away from the measurement and control shell 9.

[0080] In this embodiment, the sealed cavity specifically includes a measurement and control shell 9 and a connecting nut 15. The setting of the measurement and control shell 9 can facilitate the setting of a three-axis acceleration sensor assembly 13 in the measurement and control shell 9, and then use the three-axis acceleration sensor assembly 13 to obtain well inclination data during the inclination process; it can facilitate the setting of a battery pack 8, a drive motor 12, a measurement and control circuit and a deceleration unit 10 in the measurement and control shell 9; the setting of the connection structure is used to prevent mud from entering the measurement and control shell 9.

[0081] Secondly, in a specific implementation, the connection structure is a connecting nut 15 , a sealing ring 16 is provided between the connecting nut 15 and the measurement and control housing 9 , and a wrench hole 17 is provided on the side of the connecting nut 15 away from the measurement and control housing 9 .

[0082] In a specific embodiment, the outer sleeve of the measurement and control shell 9 is provided with an upper centralizing plate 22 and a lower centralizing plate 7, and both the upper centralizing plate 22 and the lower centralizing plate 7 are provided with through holes for mud to pass through; the lower centralizing plate 7 is limited between the lower joint 21 and the drill bit 1, and the lower centralizing plate 7 is fixedly connected to the measurement and control shell 9.

[0083] Specifically, the lower centralizing plate 7 is fixedly connected to the wall of the throttle cylinder 4 by screws, the throttle cylinder 4 is fixed to the drill bit 1 by a stop pin 11, the throttle cylinder 4 is fixedly connected to the lower centralizing plate 7, and the lower centralizing plate 7 is limited between the lower joint 21 and the throttle cylinder 4; the lower centralizing plate 7 is sleeved on the measurement and control shell 9, thereby achieving the purpose of centralizing the measurement and control shell 9 and preventing the measurement and control shell 9 from swinging; the lower centralizing plate 7 is fixedly connected to the measurement and control shell 9, thereby realizing axial limitation of the measurement and control shell 9; in addition, in order to enable mud to pass through the lower centralizing plate 7 into the throttle cylinder 4, the lower centralizing plate 7 of this embodiment is provided with a through hole for mud circulation.

[0084] Secondly, the upper centralizing plate 22 is arranged between the lower joint 21 and the lowest ball head 20, and the axial direction of the upper centralizing plate 22 is limited by the lowest ball head 20 and the lower joint 21; secondly, in order to enable the mud to pass through the upper centralizing plate 22 into the throttling tube 4, the upper centralizing plate 22 of this embodiment is also provided with a through hole for the mud to flow.

[0085] In a specific embodiment, the drill bit 1 is provided with axial cutting teeth 18 and lateral cutting teeth 3. The axial cutting teeth 18 are evenly distributed at the lower end of the drill bit 1, and the lateral cutting teeth 3 are used to generate side cutting force.

[0086] Specifically, the drill bit 1 of this embodiment is an inclined drill bit provided with axial cutting teeth 18 and lateral cutting teeth 3. The characteristics of the inclined drill bit of this embodiment are large lateral cutting force, small axial force, less and more evenly distributed total number of cutting teeth than a horizontal drilling drill bit, slow footage speed of the inclined section, and symmetrical distribution of mud flow holes 2 and cutting teeth at the end of the drill bit.

[0087] It should be noted that, unless otherwise specified, the technical or scientific terms used in this application should have the common meanings understood by those skilled in the art to which this disclosure belongs.

[0088] In addition, the terms "one", "two", etc. are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. In the description of this disclosure, the meaning of "multiple" is more than two, unless otherwise clearly and specifically limited.

[0089] In this application, unless otherwise expressly specified or limited, terms such as "mounted," "connected," "connect," and "fixed" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal connections between two components or interactions between two components. Those skilled in the art will understand the specific meanings of these terms in this disclosure based on specific circumstances.

[0090] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present disclosure, rather than to limit them. Although the present disclosure has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some or all of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present disclosure, and they should all be included in the scope of the claims and specification of the present disclosure. In particular, as long as there is no structural conflict, the various technical features mentioned in the various embodiments can be combined in any way. The present disclosure is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

Claims

1. An ultra-short radius side drilling deflection device, characterized in that: It comprises a flexible drill rod composed of a plurality of flexible short sections, wherein a central flow channel is arranged inside the flexible drill rod, a drill bit is connected to the lower end of the flexible drill rod, and a mud flow hole communicating with the central flow channel is arranged at the end of the drill bit; A sealed cavity is fixed in the central flow channel near the drill bit, and a well inclination data acquisition unit and a pressure pulse generating unit are provided in the sealed cavity, wherein the well inclination data acquisition unit is used to acquire the well inclination data during the well inclination process so as to obtain a control pulse according to the well inclination data, and the pressure pulse generating unit is used to adjust the mud flow through the mud flow hole according to the control pulse to generate a corresponding mud pressure pulse, so that the ground can receive the mud pressure pulse and decode the inclination information.

2. The ultra-short radius side drilling and deflection device according to claim 1, characterized in that: The well deviation data acquisition unit is a three-axis acceleration sensor assembly arranged in the sealed cavity, and the three-axis acceleration sensor assembly is composed of three acceleration sensors.

3. The ultra-short radius side drilling and deflection device according to claim 1, characterized in that: The pressure pulse generating unit includes a battery pack, a drive motor and a control circuit arranged in the sealed cavity, the battery pack is used to power the control circuit, and the control circuit is used to control the drive motor. The lower end of the motor shaft of the drive motor extends out of the sealed cavity and is fixedly connected to the toothed disc. A throttle cylinder is fixedly connected to the drill bit, and a plurality of mud holes are opened on the bottom of the throttle cylinder. The toothed disc is located in the throttle cylinder and contacts with the bottom of the throttle cylinder. The rotation of the drive motor can drive the toothed disc to cover the mud holes, or drive the toothed disc not to cover the mud holes.

4. The ultra-short radius side drilling and deflection device according to claim 3, characterized in that: Several mud holes are evenly distributed on the throttle cylinder, the gear disk includes an annular block and a blocking block fixed on the outer circumference of the annular block, the blocking block can block the mud holes, the annular block is fixed on the motor shaft of the drive motor, the number of the blocking blocks is equal to the number of the mud holes, and the blocking blocks are evenly arranged.

5. The ultra-short radius side drilling and deflection device according to claim 3, characterized in that: An arc groove is provided on the toothed disc, and a limit pin is fixedly connected to the bottom of the throttling cylinder. The limit pin is located in the arc groove. The limit pin is used to limit the extreme rotation angle of the toothed disc from one extreme position to another extreme position, and when the toothed disc rotates to one of the extreme positions, the blocking area of ​​the mud hole by the toothed disc is the largest, and when the toothed disc rotates to the other extreme position, the toothed disc does not block the mud hole.

6. The ultra-short radius side drilling deflection device according to claim 5, characterized in that: The maximum rotation angle of the toothed disc is 45 degrees, and the maximum blocking area of ​​the mud hole by the toothed disc is 20% of the maximum flow area of ​​the mud hole; a reduction unit is arranged in the sealing cavity, the drive motor is connected to the reduction unit, and the output shaft of the reduction unit is connected to the toothed disc through a connecting pin; the number of the mud flow holes is equal to the number of the mud holes, and each of the mud holes is opposite to one of the mud flow holes.

7. The ultra-short radius side drilling and deflection device according to claim 3, characterized in that: The control circuit comprises a first triode, a second triode, a first relay and a second relay, wherein the first triode is turned on so that the coil of the first relay is energized, and the second triode is turned on so that the coil of the second relay is energized; The first relay has two contacts: a first relay contact 1 and a first relay contact 2; the second relay has two contacts: a second relay contact 1 and a second relay contact 2; The C fixed end of the first relay contact 1 is connected to the B active end of the second relay contact 1 and the A active end of the second relay contact 2, the A active end of the first relay contact 1 is connected to the positive electrode of the battery pack, and the B active end of the first relay contact 1 is suspended; The C fixed end of the first relay contact 2 is connected to the A active end of the second relay contact 1 and the B active end of the second relay contact 2, the A active end of the first relay contact 2 is connected to the negative electrode of the battery pack, and the B active end of the first relay contact 2 is suspended; The C fixed end of the second relay contact 1 is connected to the + pin of the drive motor, and the C fixed end of the second relay contact 2 is connected to the - pin of the drive motor; The coil of the first relay is energized to connect the C fixed end of the first relay contact 1 with the A movable end of the first relay contact 1, and to connect the C fixed end of the first relay contact 2 with the A movable end of the first relay contact 2; The coil of the second relay is energized to connect the C fixed end of the second relay contact one with the A movable end of the second relay contact one, and to connect the C fixed end of the second relay contact two with the A movable end of the second relay contact two.

8. The ultra-short radius side drilling and deflection device according to claim 1, characterized in that: Each of the flexible short sections includes a ball head, and the upper end of each of the ball heads is connected to an outer casing via a torque pin. The uppermost outer casing is fixedly connected to an upper joint, and the lower end of the lowest ball head is fixedly connected to a lower joint, and the lower joint is fixedly connected to the drill bit. The lower end of each of the remaining ball heads is fixedly connected to a connecting sleeve, and each connecting sleeve is fixedly connected to the outer casing below it. A gap that allows the flexible drill rod to bend is provided between each torque pin and the ball head, between the lowest outer casing and the lower joint, and between each of the remaining outer casings and the connecting sleeves below them.

9. The ultra-short radius side drilling and deflection device according to claim 8, characterized in that: The sealing cavity is arranged in a space formed by the lowest ball head, the lower joint and the drill bit.

10. The ultra-short radius side drilling deflection device according to claim 8, characterized in that: The sealed cavity includes a measurement and control shell, which is fixed in the central flow channel near the drill bit, and the upper end of the measurement and control shell is sealed and connected with a connecting structure; the connecting structure is a connecting nut, a sealing ring is arranged between the connecting nut and the measurement and control shell, and a wrench hole is arranged on the side of the connecting nut away from the measurement and control shell.

11. The ultra-short radius side drilling and deflection device according to claim 10, characterized in that: The outer sleeve of the measurement and control shell is provided with an upper centralizing plate and a lower centralizing plate, and the upper centralizing plate and the lower centralizing plate are both provided with through holes for mud to pass through; the lower centralizing plate is limited between the lower joint and the drill bit, and the lower centralizing plate is fixedly connected to the measurement and control shell.

12. The ultra-short radius side drilling and deflection device according to claim 1, characterized in that: The drill bit is provided with axial cutting teeth and lateral cutting teeth, the axial cutting teeth are evenly distributed at the lower end of the drill bit, and the lateral cutting teeth are used to generate side cutting force.

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