A rotary steerable drilling mechanism

Abstract

The application provides a rotary steering drilling mechanism, which comprises a drill bit, a drill collar with a mud channel, multiple groups of push assembly for adjusting the drilling direction of the drill bit, a on-off valve assembly for leading mud in the mud channel into a designated push assembly, and a detection control assembly for adjusting the communication position of the on-off valve assembly and the push assembly, wherein the drill collar is connected with the drill bit; multiple groups of the push assembly are arranged along the circumference of the drill bit; the on-off valve assembly is located in the drill collar and connected with the drill bit; and the detection control assembly is fixedly installed in the drill collar. The application has the advantages of simple structure, convenient operation, high directional drilling accuracy and the like.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of oil and gas drilling, in particular to a rotary steerable drilling mechanism. BACKGROUND

[0002] The rotary steerable drilling technology has been widely applied in the field of oil drilling, especially in the development and exploration process of shale oil and shale gas, which improves the wellbore quality and drilling speed, reduces the drilling cost, reduces the drilling accidents, and meets the drilling needs of high-difficulty wells such as horizontal wells, multi-lateral wells, and large displacement wells. During drilling, the rotary steerable drilling mechanism can continuously, automatically, and real-time adjust the inclination and azimuth according to the needs of the well trajectory, and realize high-precision trajectory control.

[0003] However, the existing rotary steerable drilling mechanism usually adopts a push-type rotary steering mode with a non-rotating sleeve. When encountering soft formation, the push wing rib of the existing structure is easy to sink into the formation, which not only reduces the build-up rate, but also increases the risk of downhole pipe sticking. The push wing rib is installed on the non-rotating sleeve, and due to the limitation of mechanical structure space, the push wing rib is about 0.5 meters away from the drill bit, and the build-up rate is limited. At the same time, the existing rotary steerable drilling mechanism uses independent hydraulic modules to drive each push wing rib to extend and retract, which has a complex structure and high manufacturing and maintenance costs. SUMMARY

[0004] The technical problem to be solved by the present application is to overcome the shortcomings of the prior art and provide a rotary steerable drilling mechanism with simple structure, convenient operation, and high directional drilling precision.

[0005] To solve the above technical problems, the technical solution provided by the present application is as follows:

[0006] A rotary steerable drilling mechanism, comprising a drill bit, a drill collar with a mud passage, a plurality of push assembly groups for adjusting the drilling direction of the drill bit, a on-off valve assembly for introducing mud from the mud passage into the designated push assembly group, and a detection control assembly for adjusting the communication position of the on-off valve assembly and the push assembly.

[0007] As a further improvement of the above technical solution:

[0008] The on-off valve assembly comprises a rotating shaft, a rotating disc rotating with the rotating shaft, and a fixed disc rotating with the drill bit, the rotating disc and the fixed disc being sleeved on the rotating shaft; the rotating disc is provided with a rotating disc slurry passage hole, and the fixed disc is provided with a fixed disc slurry passage hole corresponding to the number of the push assembly; the rotating shaft drives the rotating disc slurry passage hole to rotate to the communication position of the designated push assembly; when the fixed disc slurry passage hole rotates to communicate with the rotating disc slurry passage hole, the mud in the mud channel enters the designated push assembly.

[0009] The on-off valve assembly further comprises a limiting disc and a compression ring, the rotating disc is arranged between the fixed disc and the limiting disc, and is axially limited by the compression ring arranged on one side of the limiting disc; the limiting disc rotates with the drill bit, and the limiting disc is provided with a plurality of limiting disc slurry passage holes corresponding to the fixed disc slurry passage holes.

[0010] Further comprising a connecting seat fixedly connected with the drill bit, the connecting seat comprises a disc body mounting portion and a mud flow portion, wherein the rotating disc, the fixed disc and the limiting disc are all mounted in the disc body mounting portion; the mud flow portion is provided with a plurality of shunt holes corresponding to the number of the push assembly, the drill bit is provided with a plurality of axial slurry passage holes extending to the bottom end of each push assembly, and the two ends of each shunt hole are respectively communicated with the corresponding fixed disc slurry passage hole and the axial slurry passage hole.

[0011] The push assembly comprises a piston component, the piston component comprises a piston sleeve, a piston and a piston nozzle sleeved in sequence from the outside to the inside, wherein the piston nozzle is provided with a large-diameter inlet section, a tapered transition section and a small-diameter outlet section arranged in sequence from the center to the periphery of the drill bit, so as to generate a pressure difference when the mud enters the push assembly; the piston moves along the axial direction of the piston sleeve under the action of the pressure difference, and an axial limiting portion is arranged between the piston sleeve and the piston to prevent the piston from falling out.

[0012] The push assembly further comprises a piston cover plate, the piston cover plate is fixedly installed on the drill bit and compresses the piston sleeve; the piston cover plate is provided with a through hole for the piston to pass through.

[0013] The detection control assembly comprises an attitude sensor unit, a control circuit, a driving motor and a data uploading unit, wherein the control circuit receives the formation detection value of the attitude sensor unit and transmits it to the ground through the data uploading unit; the control circuit controls the rotation of the driving motor according to the ground instruction transmitted from the ground; the driving motor is connected with the on-off valve assembly to adjust the communication position of the on-off valve assembly and the push assembly.

[0014] The detection control assembly further comprises a mud-driven generator, the mud flow rate of the mud channel is controlled by ground command to adjust the rotating speed of the rotor of the generator, and the control circuit decodes the ground command according to the rotating speed of the rotor of the generator to control the rotating speed and direction of the driving motor.

[0015] The attitude sensor unit comprises an accelerometer, a magnetic position meter, a rotating speed gyroscope, a temperature sensor and a sensor acquisition circuit, wherein the accelerometer detects the inclination and tool face of the drilling mechanism, the magnetic position meter detects the azimuth of the drilling mechanism, the rotating speed gyroscope detects the rotating speed of the drilling mechanism, the temperature sensor detects the temperature of the rotating speed gyroscope to compensate the rotating speed error of the rotating speed gyroscope, and the sensor acquisition circuit acquires each detection data and sends to the control circuit.

[0016] The detection control assembly further comprises a mounting skeleton and two support seats arranged at two ends of the mounting skeleton, the mounting skeleton is fixedly installed on the middle part of the drill collar through the support seats, the support seat is provided with a support seat mud passing hole for the mud to pass through, the attitude sensor unit, the control circuit, the driving motor and the data uploading unit are arranged in the mounting skeleton, the rotor of the generator is arranged outside the mounting skeleton, and the stator of the generator is arranged in the mounting skeleton.

[0017] Compared with the prior art, the present application has the following advantages:

[0018] The present application directly provides the extension power source of the pushing assembly by the mud, avoids the problems of complex structure and high cost of setting an independent hydraulic system, and sets the on-off valve assembly to introduce the mud in the mud channel into the specified pushing assembly, sets the detection control assembly to adjust the communication position of the on-off valve assembly and the pushing assembly, that is, the present application controls the mud to flow into the lower part of the specified pushing assembly through the combined setting of the on-off valve assembly and the detection control assembly, so that the pushing assembly pushes the well wall at a given azimuth, effectively realizes the deflection of the drill bit along the fixed direction, achieves the purpose of directional drilling, is convenient to operate, has high safety and reliability, and the on-off valve assembly and the detection control assembly are installed in the drill collar, so that the structure is compact and the occupied space is small.

[0019] The pushing assembly of the present application is arranged at intervals along the circumference of the drill bit, that is, the pushing assembly is arranged on the drill bit, which avoids the problem that the pushing assembly arranged on the drill collar cannot accurately control the trajectory, makes the drilling trajectory control more accurate, and improves the theoretical build-up rate of the drilling mechanism. BRIEF DESCRIPTION OF DRAWINGS

[0020] The present application will be described in more detail below based on the embodiments and with reference to the accompanying drawings. Among them:

[0021] Figure 1is a perspective view of the rotary steering drilling mechanism of the present application.

[0022] Figure 2 is a sectional view of the rotary steering drilling mechanism of the present application.

[0023] Figure 3 is a sectional view of the push assembly of the present application.

[0024] Figure 4 is an exploded view of the on-off valve assembly of the present application.

[0025] Figure 5 is a sectional view of the connecting seat of the present application.

[0026] The various reference signs in the drawings represent:

[0027] 1, drill bit; 11, axial through-passage hole; 2, drill collar; 21, mud passage; 3, push assembly; 31, piston sleeve; 32, piston; 33, piston nozzle; 331, large-diameter inlet section; 332, tapered transition section; 333, small-diameter outlet section; 34, axial limiting portion; 341, piston limiting step; 342, piston sleeve limiting step; 35, piston cover plate; 4, on-off valve assembly; 41, rotating shaft; 42, rotating disc; 421, rotating disc through-passage hole; 43, fixed disc; 431, fixed disc through-passage hole; 44, limiting disc; 441, limiting disc through-passage hole; 45, compression ring; 5, detection and control assembly; 51, attitude sensor unit; 52, control circuit; 53, drive motor; 54, data uploading unit; 55, generator; 551, rotor; 552, stator; 55, mounting framework; 56, support seat; 561, support seat through-passage hole; 6, connecting seat; 61, disc body mounting portion; 62, mud flow-through portion; 621, shunt hole; 7, limiting member; 71, polygonal through-hole; 72, polygonal clamping portion. DETAILED DESCRIPTION

[0028] The present application will be further described in conjunction with the accompanying drawings and specific examples, but the protection scope of the present application is not limited by the same.

[0029] As Figure 1 and Figure 2As shown, the rotary steering drilling mechanism of the embodiment comprises a drill bit 1, a drill collar 2, an on-off valve assembly 4, a detection control assembly 5 and multiple sets of pushing assembly 3. The drill collar 2 is internally provided with a mud channel 21; the drill collar 2 is connected with the drill bit 1 to rotate with the drill bit 1; the multiple sets of pushing assembly 3 are arranged along the circumference of the drill bit 1 to adjust the drilling direction of the drill bit 1; the on-off valve assembly 4 is located in the drill collar 2 and connected with the drill bit 1 to introduce the mud in the mud channel 21 into the specified pushing assembly 3; the detection control assembly 5 is fixedly installed in the drill collar 2 to adjust the communication position of the on-off valve assembly 4 and the pushing assembly 3. The structure is compact and occupies small space.

[0030] The present application directly provides the telescopic power source of the pushing assembly 3 by mud, avoids the problem of complex structure and high cost of setting independent hydraulic system; at the same time, the on-off valve assembly 4 can introduce the mud in the mud channel 21 into the specified pushing assembly 3, and the detection control assembly 5 can adjust the communication position of the on-off valve assembly 4 and the pushing assembly 3, that is, the present application can control the mud to flow into the lower part of the specified pushing assembly 3 by the combined setting of the on-off valve assembly 4 and the detection control assembly 5, which makes the pushing assembly 3 push the well wall at a given direction of the stratum, effectively realizes the deflection of the drill bit 1 along the fixed direction, and achieves the purpose of directional drilling, which is convenient to operate and has high safety and reliability.

[0031] At the same time, the pushing assembly 3 is arranged along the circumference of the drill bit 1, that is, the pushing assembly 3 is arranged on the drill bit 1, which avoids the problem that the pushing assembly 3 cannot be accurately controlled when it is arranged on the drill collar 2, makes the drilling trajectory control more accurate, and improves the theoretical build-up rate of the drilling mechanism.

[0032] As shown, Figure 4 The on-off valve assembly 4 comprises a rotating shaft 41, a rotating disc 42 and a fixed disc 43. The rotating disc 42 and the fixed disc 43 are sleeved on the rotating shaft 41, the rotating disc 42 rotates with the rotating shaft 41, and the fixed disc 43 rotates with the drill bit 1; at the same time, the rotating disc 42 is provided with a rotating disc mud passing hole 421, the fixed disc 43 is provided with multiple fixed disc mud passing holes 431, the number of the fixed disc mud passing holes 431 is the same as that of the pushing assembly 3, and the fixed disc mud passing holes 431 are in one-to-one correspondence with the pushing assembly 3. The structure is compact and occupies small space, which can be arranged in the limited space of the drill collar 2 to realize the mud on-off function.

[0033] During directional drilling, the rotating shaft 41 drives the rotating disc mud passing hole 421 to rotate to the communication position of the specified pushing assembly 3; when the drill bit 1 drives the fixed disc mud passing hole 431 to rotate to communicate with the rotating disc mud passing hole 421, the mud in the mud channel 21 enters the specified pushing assembly 3 through the rotating disc mud passing hole 421 and the fixed disc mud passing hole 431, which realizes the effective pushing of the specified pushing assembly 3 and achieves the purpose of directional drilling, which is convenient to operate and has high efficiency.

[0034] Further, the on-off valve assembly 4 further comprises a limiting disc 44 and a pressing ring 45. The rotating disc 42 is arranged between the fixing disc 43 and the limiting disc 44, and gaps are left between the two ends of the rotating disc 42 and the fixing disc 43 and the limiting disc 44. The rotating disc 42 is axially limited by the pressing ring 45 arranged on one side of the limiting disc 44, which can avoid the problem of mutual interference of the disc bodies when rotating while limiting the axial displacement of the rotating disc 42.

[0035] Meanwhile, the limiting disc 44 and the fixing disc 43 rotate with the drill bit 1. The limiting disc 44 is provided with a plurality of limiting disc slurry passing holes 441, and the number of the limiting disc slurry passing holes 441 is the same as that of the fixing disc slurry passing holes 431. Meanwhile, one end of the limiting disc slurry passing hole 441 is arranged in one-to-one correspondence with the fixing disc slurry passing hole 431, and the other end of the limiting disc slurry passing hole 441 communicates with the mud channel 21. When the rotating disc slurry passing hole 421 communicates with the limiting disc slurry passing hole 441, the mud in the mud channel 21 flows into the fixing disc slurry passing hole 431 from the limiting disc slurry passing hole 441, so as to achieve the purpose of mud flow.

[0036] Further, a limiting component 7 is arranged between the rotating shaft 41 and the rotating disc 42. The limiting component 7 comprises a polygonal through hole 71 and a polygonal clamping part 72. The polygonal through hole 71 is arranged on the rotating disc 42, and the polygonal clamping part 72 is arranged on the rotating shaft 41. The polygonal through hole 71 and the polygonal clamping part 72 are clamped and matched with each other, so as to make the rotating disc 42 rotate with the rotating shaft 41.

[0037] As Figure 2 and Figure 5 described, the rotary steerable drilling mechanism further comprises a connecting seat 6. The connecting seat 6 is fixedly connected with the drill bit 1 and rotates with the drill bit 1. The connecting seat 6 comprises a disc body mounting part 61 and a mud flow part 62. The disc body mounting part 61 is provided with a cylindrical mounting groove, and the rotating disc 42, the fixing disc 43 and the limiting disc 44 are all mounted in the cylindrical mounting groove. The fixing disc 43 and the limiting disc 44 are both screwed in the cylindrical mounting groove, so as to rotate with the drill bit 1.

[0038] Meanwhile, the mud flow part 62 is provided with a plurality of shunt holes 621, and the drill bit 1 is provided with a plurality of axial slurry passing holes 11. The number of the shunt holes 621 and the number of the axial slurry passing holes 11 are both the same as the number of the pushing assembly 3. The two ends of the shunt hole 621 respectively communicate with the corresponding fixing disc slurry passing hole 431 and the axial slurry passing hole 11, and the other end of the axial slurry passing hole 11 extends to the bottom end of each pushing assembly 3. When the on-off valve assembly 4 is opened, the mud in the mud channel 21 enters the shunt hole 621 and the axial slurry passing hole 11 through the on-off valve assembly 4, so as to push out the pushing assembly 3.

[0039] In the embodiment, the three groups of push assembly 3 are uniformly distributed along the circumference of the drill bit 1. Meanwhile, the axial through-passage hole 11, the distribution hole 621, the through-passage hole 431 of the fixed disc, and the through-passage hole 441 of the limiting disc are all provided with three, and when the through-passage hole 421 of the rotating disc is communicated with one of the through-passage holes 431 of the fixed disc, the mud passage 21 and the push assembly 3 form a through-passage flow channel for the mud. In other embodiments, the number of the push assembly 3 can be adjusted according to actual conditions, such as four groups, five groups, etc., and at this time, the number of the axial through-passage hole 11, the distribution hole 621, the through-passage hole 431 of the fixed disc, and the limiting disc 44 are adjusted accordingly.

[0040] As shown in Figure 2 and Figure 3 The push assembly 3 includes a piston component. The piston component includes a piston sleeve 31, a piston 32, and a piston nozzle 33. The piston sleeve 31, the piston 32, and the piston nozzle 33 are sequentially arranged from the outside to the inside, the piston 32 can move along the axial direction of the piston sleeve 31, and the piston nozzle 33 is fixedly installed in the piston 32. The piston nozzle 33 is provided with a large-diameter inlet section 331, a tapered transition section 332, and a small-diameter outlet section 333, which are sequentially arranged from the center of the drill bit 1 to the outer periphery, and the large-diameter inlet section 331 is communicated with the corresponding axial through-passage hole 11. The arrangement of the mud injection hole of the piston nozzle 33 of the present application causes a pressure difference when the mud enters the push assembly 3, so that the piston 32 moves along the axial direction of the piston sleeve 31 under the action of the pressure difference, so as to push against the well wall and realize directional drilling function.

[0041] Meanwhile, an axial limiting portion 34 is arranged between the piston sleeve 31 and the piston 32 to prevent the piston 32 from being pulled out during movement. Further, the axial limiting portion 34 includes a piston limiting step 341 arranged on the piston 32 and a piston sleeve limiting step 342 arranged on the piston sleeve 31, and when the piston 32 moves along the axial direction of the piston sleeve 31 to a certain position, the piston limiting step 341 and the piston sleeve limiting step 342 are limited to prevent the piston 32 from being pulled out, thereby improving the safety and reliability of directional drilling.

[0042] In the embodiment, the piston component of each push assembly 3 is provided with two groups, and the two groups of piston components are arranged along the axial direction of the drill bit 1 to ensure sufficient pushing force and improve the effect of directional drilling. In other embodiments, the number of the piston component of each push assembly 3 can be adjusted according to actual conditions, such as three groups, four groups, etc.

[0043] In the embodiment, the piston nozzle 33 is an erosion-resistant nozzle, which effectively reduces the erosion of the piston 32 by mud. The piston nozzle 33 can be replaced to realize the replacement and maintenance of the piston component, which improves the service life of the piston component and reduces the maintenance cost. Meanwhile, the piston nozzle 33 is screwed in the piston 32, which facilitates the replacement.

[0044] Further, the pushing assembly 3 further comprises a piston cover plate 35. The piston cover plate 35 is fixedly installed on the drill bit 1 by fasteners, and the piston cover plate 35 presses the piston sleeve 31 to prevent the piston sleeve 31 from falling off. The piston cover plate 35 is provided with a through hole for the piston 32 to pass through and push against the well wall.

[0045] As shown in Figure 2 The detection and control assembly 5 comprises a posture sensor unit 51, a control circuit 52, a driving motor 53 and a data uploading unit 54. The control circuit 52 receives the formation detection value of the posture sensor unit 51 and transmits it to the ground through the data uploading unit 54. Then, the control circuit 52 compares the formation detection value with the design value to calculate an adjustment value and sends a ground instruction according to the adjustment value. The control circuit 52 controls the driving motor 53 to rotate according to the ground instruction transmitted from the ground. The driving motor 53 is drivingly connected with the rotating shaft 41 of the on-off valve assembly 4 to control the rotating shaft 41 to rotate to the rotating disc mud hole 421 corresponding to the specified pushing assembly 3, which realizes the precise adjustment of the drilling steering function.

[0046] Further, the detection and control assembly 5 further comprises a generator 55, which comprises a rotor 551 and a stator 552. The mud circulation drives the rotor 551 to rotate, and at this time, the generator 55 generates electricity, which, after rectification, can provide power for the control circuit 52, the posture sensor unit 51, the data uploading unit 54 and the driving motor 53. Meanwhile, the ground instruction controls the speed of the generator 55 through the mud flow. The control circuit 52 has a detection component for detecting the speed of the generator 55. The control circuit 52 decodes the ground instruction by detecting the change of the speed of the generator 55 and controls the steering and speed of the driving motor 53 according to the decoding, so as to realize the rapid and precise adjustment of the pushing direction.

[0047] In the embodiment, the attitude sensor unit 51 comprises an accelerometer, a magnetic position meter, a rotational speed gyroscope, a temperature sensor and a sensor acquisition circuit. The accelerometer detects the inclination and tool face of the drilling mechanism; the magnetic position meter detects the azimuth of the drilling mechanism; the rotational speed gyroscope detects the rotational speed of the drilling mechanism; the temperature sensor detects the temperature of the rotational speed gyroscope, so as to increase or decrease the corresponding temperature drift rotational speed difference according to the test temperature, to compensate for the rotational speed error of the rotational speed gyroscope caused by temperature, and to ensure the accuracy of the detection result. At the same time, the sensor acquisition circuit collects each detection data and sends it to the control circuit 52, the control circuit 52 sends each detection data received to the data uploading unit 54, and the data uploading unit 54 transmits it to the pulser above the drill collar 2 in a wireless manner, and then transmits it to the ground through the pulser. The setting of each sensor detector of the attitude sensor unit 51 ensures the detection accuracy of each formation detection value, and improves the accurate control of the subsequent directional drilling function.

[0048] As shown in Figure 1 and Figure 2 , the detection control assembly 5 further comprises a mounting skeleton 55 and two support seats 56. The two support seats 56 are respectively arranged at the two ends of the mounting skeleton 55, and the mounting skeleton 55 is fixedly installed on the middle part of the drill collar 2 through the support seats 56, so as to rotate synchronously with the drill collar 2; at the same time, the support seat 56 is provided with a support seat slurry passing hole 561 for effective passing of the mud. The attitude sensor unit 51, the control circuit 52, the driving motor 53 and the data uploading unit 54 are all arranged in the mounting skeleton 55, the rotor 551 of the generator 55 is sleeved outside the mounting skeleton 55, and the stator 552 of the generator 55 is arranged in the mounting skeleton 55, so that the layout is compact and the occupied space is small.

[0049] In directional drilling, the control circuit 52 controls the driving motor 53 to rotate according to the ground instruction, at this time, the rotating disc through-hole 421 of the rotating disc 42 rotates to a given orientation relative to the stratum to correspond to the designated push assembly 3, then the control circuit 52 controls the driving motor 53 to fix the rotating disc through-hole 421 at the given orientation. At this time, the fixed disc 43, the limiting disc 44 and the connecting seat 6 rotate with the drill bit 1 relative to the stratum, when one of the fixed disc through-holes 431 on the fixed disc 43 rotates to the position of the rotating disc through-hole 421, a limiting disc through-hole 441, the rotating disc through-hole 421, the fixed disc through-hole 431 and one of the shunt holes 621 are communicated, the mud in the mud channel 21 passes through the above-mentioned holes and enters the bottom end of a group of push assemblies 3; the mud flows out of the piston nozzle 33, because the inlet diameter of the piston nozzle 33 is larger than the outlet diameter, and the mud pressure in the piston nozzle 33 is higher than the annular pressure outside the drill bit 1, therefore, the high liquid pressure pushes the piston 32 out. When the fixed disc 43 continues to rotate, the fixed disc through-hole 431 is disengaged from the rotating disc through-hole 421, and the corresponding push assembly 3 no longer has mud flowing in, the liquid pressure in the piston 32 is equal to the annular pressure outside the drill bit 1, at this time, the piston 32 is retracted under the action of the external force. When the other fixed disc through-hole 431 of the fixed disc 43 is communicated with the rotating disc through-hole 421, the corresponding piston 32 is pushed out; then, with the continuous rotation of the fixed disc 43, the corresponding piston 32 is retracted.

[0050] If the ground instruction is not received, the rotating disc 42 remains stationary relative to the stratum, and the drill bit 1 rotates relative to the stratum to drive the fixed disc 43 and the limiting disc 44 to rotate, at this time, the piston 32 of the same push assembly 3 is repeatedly pushed out to realize directional drilling in a certain direction. When the ground instruction is received, the rotating disc through-hole 421 of the rotating disc 42 rotates to a given orientation relative to the stratum to correspond to the designated push assembly 3, and realizes drilling direction change, so that the drill bit 1 accurately and quickly reaches the target stratum.

[0051] Although the present application has been described with reference to the preferred embodiments, various modifications can be made to the application and equivalents thereof without departing from the scope of the application. In particular, the technical features mentioned in each embodiment can be combined in any manner as long as there is no structural conflict. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A rotary steerable drilling mechanism, characterized in that, The application relates to a drilling device, which comprises a drill bit, a drill collar with a mud channel, multiple groups of push assembly for adjusting the drilling direction of the drill bit, a switch valve assembly for leading mud in the mud channel into a specified push assembly, and a detection control assembly for adjusting the communication position of the switch valve assembly and the push assembly, wherein the drill collar is connected with the drill bit; multiple groups of the push assembly are arranged along the circumference of the drill bit; the switch valve assembly is arranged in the drill collar and connected with the drill bit; the detection control assembly is fixedly arranged in the drill collar; the switch valve assembly comprises a rotating shaft, a rotating disc rotating with the rotating shaft, and a fixed disc rotating with the drill bit; the rotating disc and the fixed disc are sleeved on the rotating shaft; the rotating disc is provided with a rotating disc mud passing hole; the fixed disc is provided with fixed disc mud passing holes which are equal in number to the push assemblies; the rotating shaft drives the rotating disc mud passing hole to rotate to the communication position of a specified push assembly; when the fixed disc mud passing hole rotates to the communication position of the rotating disc mud passing hole, mud in the mud channel enters the specified push assembly; the switch valve assembly further comprises a limiting disc and a compression ring; the rotating disc is arranged between the fixed disc and the limiting disc and is axially limited by the compression ring arranged on one side of the limiting disc; the limiting disc rotates with the drill bit; the limiting disc is provided with limiting disc mud passing holes which are equal in number to the fixed disc mud passing holes; the device further comprises a connecting seat fixedly connected with the drill bit; the connecting seat comprises a disc body mounting part and a mud passing part; the rotating disc, the fixed disc and the limiting disc are arranged in the disc body mounting part; the mud passing part is provided with a plurality of shunt holes which are equal in number to the push assemblies; the drill bit is provided with axial mud passing holes which extend to the bottom ends of the push assemblies; the two ends of each shunt hole are respectively connected with the corresponding fixed disc mud passing hole and the axial mud passing hole, The push assembly comprises a piston component, the piston component comprises a piston sleeve, a piston and a piston nozzle which are sequentially sleeved from outside to inside; the piston nozzle is provided with a large-diameter inlet section, a tapered transition section and a small-diameter outlet section which are sequentially arranged from the center of the drill bit to the periphery, so that a pressure difference is generated when mud enters the push assembly; the piston moves along the axial direction of the piston sleeve under the action of the pressure difference, so as to abut against the well wall.

2. The rotary steerabiie drilling mechanism of claim 1, wherein, An axial limiting part is arranged between the piston sleeve and the piston to prevent the piston from falling out.

3. The rotary steerabiie drilling mechanism of claim 2, wherein, The push assembly further comprises a piston cover plate which is fixedly arranged on the drill bit and compresses the piston sleeve; the piston cover plate is provided with a through hole through which the piston passes.

4. The rotary steerabiie drilling mechanism of claim 1, wherein, The detection control assembly comprises an attitude sensor unit, a control circuit, a driving motor and a data uploading unit; the control circuit receives the formation detection value of the attitude sensor unit and transmits the value to the ground through the data uploading unit; the control circuit controls the rotation of the driving motor according to the ground instruction transmitted from the ground; the driving motor is connected with the switch valve assembly to adjust the communication position of the switch valve assembly and the push assembly.

5. The rotary steerable drilling assembly of claim 4, wherein, The detection control assembly further comprises a mud-driven generator, the mud flow rate of the mud channel is controlled by ground command to adjust the rotating speed of the rotor of the generator; the control circuit decodes the ground command according to the rotating speed of the rotor of the generator to control the rotating speed and direction of the driving motor.

6. The rotary steerable drilling assembly of claim 4, wherein, The attitude sensor unit comprises an accelerometer, a magnetic position meter, a rotating speed gyroscope, a temperature sensor and a sensor acquisition circuit, wherein the accelerometer detects the inclination and tool face of the drilling mechanism, the magnetic position meter detects the azimuth of the drilling mechanism, the rotating speed gyroscope detects the rotating speed of the drilling mechanism, the temperature sensor detects the temperature of the rotating speed gyroscope to compensate the rotating speed error of the rotating speed gyroscope, and the sensor acquisition circuit acquires each detection data and sends to the control circuit.

7. The rotary steerable drilling assembly of claim 5, wherein, The detection control assembly further comprises a mounting skeleton and two support seats arranged at two ends of the mounting skeleton, the mounting skeleton is fixedly installed on the middle part of the drill collar through the support seats, the support seats are provided with support seat mud passing holes for mud passing, the attitude sensor unit, the control circuit, the driving motor and the data uploading unit are arranged in the mounting skeleton, the rotor of the generator is arranged outside the mounting skeleton, and the stator of the generator is arranged in the mounting skeleton.

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