CN115247535A

CN115247535A - Rotary guide drilling tool

Info

Publication number: CN115247535A
Application number: CN202110448977.XA
Authority: CN
Inventors: 徐梓辰; 万晓跃
Original assignee: Individual
Current assignee: Individual
Priority date: 2021-04-25
Filing date: 2021-04-25
Publication date: 2022-10-28
Also published as: WO2022228397A1

Abstract

The invention provides a rotary steering drilling tool, which comprises a drill bit, a steering knuckle, a flexible drill column, a propelling mechanism and an electric drive actuator, wherein the steering knuckle comprises a bearing body, the drill bit is connected to the lower part of the bearing body, and the bearing body is connected with a steering mechanism; the flexible drill string comprises a torque transmission serial and a pressure-bearing hose, and the lower end of the torque transmission serial is connected with the upper end of the bearing body; the propelling mechanism is connected to the bearing body and communicated with the flexible drill column, and can drive the drill bit to drill or pull the flexible drill column to advance; the electric drive actuator is electrically connected with the guide mechanism and can control the action of the guide mechanism. The rotary steering drilling tool can realize short-radius directional drilling, and the propelling mechanism can well assist the flexible drill column to advance or push the drill bit to drill, so that short-radius steering drilling with certain well hole extension length is realized.

Description

Rotary guide drilling tool

Technical Field

The invention relates to the technical field of drilling and oil and gas exploitation, in particular to a rotary steering drilling tool.

Background

Exploration and development of underground material resources and space resources requires extensive application of drilling techniques. The existing steering drilling technology mainly comprises a downhole motor steering drilling technology and a rotary steering drilling technology. The maximum build-up rate of the technology can not exceed 15 degrees/30 meters generally, and the short-radius pilot drilling of the drilling controllable track cannot be realized or the pilot drilling can be continued at the bottom end of the existing short-radius well section. In the prior art, a plurality of radial or short-radius drilling technologies which cannot effectively control the well track exist, and the technologies have poor effects on developing and utilizing underground resources.

Disclosure of Invention

The object of the present invention is to provide a rotary steerable drilling tool that enables a certain wellbore extension length.

To achieve the above object, the present invention provides a rotary steerable drilling tool, comprising:

a drill bit;

the guide joint comprises a bearing body, the drill bit is connected to the lower part of the bearing body, and a guide mechanism is connected to the bearing body;

the flexible drill string comprises a torque transmission serial and a pressure-bearing hose, wherein the torque transmission serial is arranged inside the pressure-bearing hose in a penetrating manner, or the pressure-bearing hose is arranged inside the torque transmission serial in a penetrating manner, and the lower end of the torque transmission serial is connected with the upper end of the bearing body;

the propelling mechanism is connected to the bearing body and communicated with the flexible drill string, and can drive the drill bit to drill or pull the flexible drill string to advance;

and the electric drive actuator is electrically connected with the guide mechanism and can control the action of the guide mechanism.

The tool as described above, wherein the propulsion mechanism comprises at least two anti-jet nozzles spaced circumferentially around the carrier body, the inlets of the anti-jet nozzles communicating with the through flow passage in the interior of the flexible drill string.

The rotary steerable drilling tool as described above, wherein the propulsion mechanism comprises a drainage nozzle and a closure structure, the closure structure having a throat, the drainage nozzle being disposed in a lower portion of the throat, the throat communicating with a through flow passage in the interior of the flexible drill string through the drainage nozzle.

The rotary steering drilling tool comprises a bearing body, wherein the torque transmission string comprises a plurality of torque transmission short sections which are sequentially connected from top to bottom, two adjacent torque transmission short sections are rotatably connected through a variable-angle force transmission structure, and the torque transmission short section positioned at the lowest position is connected with the bearing body.

The rotary steerable drilling tool as described above, wherein the deflection limit between any of the torque transmitting subs is 2 ° or greater.

The rotary steerable drilling tool of the above, wherein the torque transfer sub has a length less than or equal to 5 times the diameter of the load-bearing body.

The rotary steerable drilling tool as described above, wherein the torque transfer sub has a length of 30% to 300% of the diameter of the load-bearing body.

The rotary steering drilling tool comprises a universal joint and a sleeve sleeved outside the universal joint, wherein a gap is formed between the sleeve and the universal joint to form a deflection space, and the universal joint can deflect 0.5-15 degrees relative to the axis of the sleeve in the deflection space.

The rotary steerable drilling tool as described above, wherein the variable angle force transfer structure comprises a ball seat and a ball head, one of the ball head and the ball seat is provided with a torque transfer groove, and the other of the ball head and the ball seat is provided with a torque transfer pin, the torque transfer pin being rotatably received in the torque transfer groove.

The rotary steerable drilling tool as described above, wherein the pressurized hose is a composite tube, a rubber tube, or a slotted tube filled with a sealing material in a slot.

The rotary steerable drilling tool as described above, wherein a gage structure comprising scraper blades or centralizers is attached to the exterior of the carrier body.

The rotary steering drilling tool comprises a bearing body, wherein the bearing body is provided with a plurality of accommodating cavities, the accommodating cavities are arranged on the bearing body at intervals along the circumferential direction of the bearing body, a driving piston capable of extending and retracting along the radial direction of the bearing body is arranged in each accommodating cavity, the driving piston can abut against a well wall, and the extension and retraction of the driving piston can drive the bearing body to deflect in a preset direction.

The rotary steering drilling tool as described above, wherein the electric actuator includes a motor and a rotary valve, the rotary valve includes a rotary valve disc and a rotary valve seat, the rotary valve seat is fixedly connected to the bearing body, the rotary valve seat is provided with a plurality of communication holes corresponding to the receiving cavities one by one, the rotary valve disc is electrically connected to the motor, and the motor can drive the rotary valve disc to rotate relative to the rotary valve seat.

The rotary steerable drilling tool as described above, wherein, when reverse circulation drilling is used, the propulsion mechanism is a packer ring having an outer diameter of 90% to 110% of the outer diameter of the drill bit, the packer ring being capable of engaging with the inner wall surface of the borehole or maintaining a predetermined clearance.

The rotary steerable drilling tool as described above, wherein the rotary steerable drilling tool further comprises a control sub, the control sub is connected between the guide joint and the flexible drill string, or the control sub is connected to any position in the flexible drill string, or the control sub is connected to the upper end of the flexible drill string, a control circuit is arranged in the control sub, and the control circuit is electrically connected to the electric drive actuator through a jumper line.

The tool as recited above, wherein the tool further comprises a downhole power source connected to the upper end of the flexible drill string, the downhole power source being electrically connected to the control circuit.

Compared with the prior art, the invention has the following advantages:

the rotary steering drilling tool is mainly used for short plate radius steering drilling with the diameter range of 0.0254 mm-0.127 m and the turning radius of less than 10 m. The flexible drill stem is pulled by the propelling mechanism to realize bit feeding, the pressure-bearing hose bears the pulling force and plays a role in sealing, the torque transmission string only needs to realize the simple function of torque transmission, the complexity of the torque transmission string is greatly simplified, the diameter size of the flexible drill stem is greatly reduced, and bit feeding, bit pulling and torque transmission can be realized within a smaller diameter range. The guide mechanism is arranged, so that the guide mechanism can drive the drill bit to deflect in a preset direction under the rotating condition to change the track of the well hole, and the short-radius directional drilling is realized; through setting up advancing mechanism, can assist fine supplementary flexible drilling string to advance or promote the drill bit and creep into to realize having the minor diameter short radius steering drilling of certain well bore extension length. The invention adopts a composite material pipe, a rubber pipe or a slotted pipe filled with sealing materials in a slotted hole as a pressure-bearing hose, controls the weight of the flexible drill string to the maximum extent, and enables the flexible drill string to be smoothly pulled by a propelling mechanism.

Drawings

The drawings are only for purposes of illustrating and explaining the present invention and are not to be construed as limiting the scope of the present invention. Wherein:

FIG. 1 is a schematic representation of the construction of a rotary steerable drilling tool of the present invention;

FIG. 2 is an enlarged view of part A of FIG. 1;

FIG. 3 is another schematic representation of the configuration of a rotary steerable drilling tool of the present invention;

FIG. 4 is an enlarged view of the portion B of FIG. 3;

FIG. 5 is a schematic view of the structure of the enclosure;

FIG. 6 is a first schematic configuration of a flexible drill string;

FIG. 7 is a schematic view of a second configuration of a flexible drill string;

FIG. 8 is a third schematic representation of a flexible drill string;

FIG. 9 is a schematic representation of yet another configuration of a rotary steerable drilling tool of the present invention.

The reference numbers indicate:

1. a drill bit; 11. a front blade; 12. a pre-nozzle;

2. a guide section; 21. a load-bearing body; 211. a guide mechanism; 2111. an accommodating cavity; 2112. a drive piston; 212. a gauge protection structure; 22. a packing ring;

3. a flexible drill string; 31. a torque transfer string; 311. a torque transfer nipple; 312. an angle-variable force transmission structure; 3123. a ball head; 3124. a ball seat; 3125. a torque transfer slot; 3126. a torque transfer pin; 3127. a seal member; 32. a pressure-bearing hose; 33. a through flow channel;

4. a propulsion mechanism; 41. a reverse nozzle; 42. a drainage nozzle; 43. a closed structure; 431. a throat;

5. an electrically driven actuator; 51. an electric motor; 52. rotating the valve; 521. a rotary valve disc; 522. a rotary valve seat;

6. driving the drill string;

7. a whipstock;

8. an anchoring device;

9. controlling the short section; 91. a control circuit; 92. connecting a line in a bridging way;

10. a downhole power source;

z, main wellbore;

F. and branching the well bore.

Detailed Description

In order to clearly understand the technical solution, the purpose and the effect of the present invention, a detailed description of the present invention will be described with reference to the accompanying drawings. The front and the back do not represent specific directions in the invention, and only express the relative position relation of the extremely-short radius rotary guiding tool; the expression "rear" is synonymous with "upper", and the expression "front" is synonymous with "lower"; "very short radius" refers to a radius of less than 10 meters, but the specific turning radius is not limited in the present invention; in the description of the present invention, "a plurality" means two or more unless otherwise specified.

As shown in fig. 1, 2, 3 and 4, the present invention provides a rotary steerable drilling tool comprising a drill bit 1, a guide joint 2, a flexible drill string 3, a propulsion mechanism 4 and an electrically driven actuator 5, wherein:

the drill bit 1 can comprise a front blade 11 with cutting capability and a front nozzle 12 with jet rock breaking capability, in the drilling process, drilling power mainly comes from drilling pressure and torque transmitted to the front blade 11 by a flexible drill string 3, secondary power is jet rock breaking of high-pressure water jet through the front nozzle 12, the front nozzle 12 can carry rocks in time to avoid repeated breaking and cool the front blade 11 in time, or the drilling power mainly comes from jet rock breaking of the high-pressure water jet through the front nozzle 12, the secondary power is drilling pressure and torque transmitted to the front blade 11 by the flexible drill string 3, the front blade 11 can play a role in further leveling a well wall, specifically, when an angle set by the front nozzle 12 is small, the size of a new well bore formed by jet is relatively small, otherwise, when the angle set by the front nozzle 12 is large, the size of the new well bore formed by jet is relatively large, because the well bore track formed by water jet is not leveled, the working stability of a well bore guide execution mechanism formed by simple water jet rock breaking is not favorable for controlling the stable guide and stable guide of the front blade 11, the front blade is favorable for realizing the fine jet rock breaking of the main blade 11, the well bore hole is suitable for realizing the condition that the main blade 11 and the well bore hole is a fine jet rock breaking structure, the main blade 11, and the main blade 11 is favorable for realizing the fine jet rock breaking technology of the fine drill hole is small well bore hole is suitable for realizing the fine jet drill hole leveling the well bore hole.

The guide joint 2 comprises a bearing body 21, the drill bit 1 is connected to the lower part of the bearing body 21, a guide mechanism 211 is connected to the bearing body 21, and the guide mechanism 211 can drive the drill bit 1 and the guide joint 2 to deflect in a preset direction, so that the track of a well hole is changed, and a short build-up rate is realized;

the flexible drill string 3 comprises a torque transmission string 31 and a pressure-bearing hose 32, the torque transmission string 31 is arranged inside the pressure-bearing hose 32 in a penetrating manner, or the pressure-bearing hose 32 is arranged inside the torque transmission string 31 in a penetrating manner, the lower end of the torque transmission string 31 is connected with the upper end of the bearing body 21, the torque transmission string 31 is used for transmitting the torque and a small part of drilling pressure required by drilling, and the inside of the flexible drill string 3 is communicated with the inside of the bearing body 21 to form a flow channel;

the propelling mechanism 4 is connected to the bearing body 21 and communicated with the flexible drill string 3, the propelling mechanism 4 can drive the drill bit 1 to drill or pull the flexible drill string 3 to advance, the turning radius is extremely short, the flexibility of the drill string needs to be improved to the maximum extent to adapt to the extremely small turning radius, and the capacity of transmitting bit pressure of the flexible drill string 3 is reduced along with the continuous increase of the flexibility of the flexible drill string 3, so that the propelling mechanism 4 can well assist the flexible drill string 3 to advance;

the electric drive actuator 5 is electrically connected with the guide mechanism 211, and the electric drive actuator 5 can control the action of the guide mechanism 211, so that the operation of driving the guide mechanism 211 to realize rotary guide is simple and convenient.

According to the rotary steering drilling tool, the guide mechanism 211 is arranged, so that the guide mechanism 211 can drive the drill bit 1 to deflect in a preset direction under the rotating condition to change a well track, and therefore a short build-up rate is achieved; through setting up advancing mechanism 4, can assist fine supplementary flexible drilling string 3 to advance or promote drill bit 1 and bore to realize having the short radius steering drilling of certain well bore extension length.

In an embodiment of the present invention, as shown in fig. 1 and 2, the propelling mechanism 4 includes at least two counter nozzles 41 arranged at intervals along the circumferential direction of the bearing body 21, inlets of the counter nozzles 41 are communicated with the through flow channel 33 inside the flexible drill string 3, high-pressure water flow can enter the counter nozzles through the flow channel, the counter nozzles 41 provide all or part of axial force for pushing rock breaking and/or pulling the flexible drill string 3 to advance, the axial force is along the axial direction of the guide joint 2, the counter nozzles 41 realize forward drilling power provided by reverse jetting by using a drilling circulation medium conveyed by the flexible drill string 3, further, the counter nozzles 41 are matched with the drill bit 1, since the forward resistance applied to the drill bit 1 during drilling is opposite to the axial dragging force provided by the counter nozzles 41, when the drill bit 1 is mainly powered by the front blade 11, hydraulic energy is only used as an auxiliary, and the hydraulic energy of the counter nozzles 41 mainly plays a role of cleaning a borehole; when the drill bit 1 uses the jet flow nozzle as the main power, the hydraulic energy should play a role of crushing the bottom layer, the main function of the counter-nozzle 41 is to overcome the advancing resistance and provide enough axial dragging force for the extended drilling, and preferably, 3 to 8 counter-nozzles 41 are arranged along the circumferential direction of the bearing body 21.

In another embodiment of the present invention, as shown in fig. 3, 4 and 5, the propulsion mechanism 4 includes a drainage nozzle 42 and a closed structure 43, the closed structure 43 is sleeved outside the bearing body 21, the closed structure 43 has a throat 431, the drainage nozzle 42 is connected to a lower end of the throat 431, an inlet of the throat 431 is communicated with the flexible drill string 3 through the drainage nozzle 42, that is, the throat 431 is communicated with the through flow channel 33 through the drainage nozzle 42, the drainage nozzle 42 can spray high-pressure fluid toward an extending direction of the throat 431, the fluid sprayed by the drainage nozzle 42 drives the fluid below the closed structure 43 to flow to the upper side of the closed structure 43, so that a pressure difference is generated above and below the closed structure 43, and the pressure difference can push the drill bit 1 to advance.

In an embodiment of the present invention, as shown in fig. 1, fig. 3, fig. 6 and fig. 7, the torque transfer string 31 includes a plurality of torque transfer nipples 311 connected in sequence from top to bottom, two adjacent torque transfer nipples 311 are rotatably connected by the variable angle force transfer structure 312, that is, the torque transfer string 31 is a hinge structure, the torque transfer nipple 311 located at the lowermost position is connected with the bearing body 21, since the propelling device can propel the structure of the drill bit 1 to break rock, and the pressure-bearing hose 32 can bear axial force, the torque transfer nipples 311 can transfer torque for driving the drill bit 1 to rotate.

Further, the length of the torque transmission short section 311 is less than or equal to 5 times of the diameter of the bearing body 21, and the deflection limit between any torque transmission short sections 311 is more than 2 degrees, so that the torque transmission short sections 311 are fully ensured to have enough flexibility in a serial mode.

Further, the length of the torque transmission nipple 311 is 30% -300% of the diameter of the bearing body 21.

Further, the variable-angle force transmission structure 312 comprises a universal joint and a sleeve sleeved outside the universal joint, a gap is formed between the sleeve and the universal joint to form a deflection space, the universal joint can deflect 0.5-15 degrees in the deflection space relative to the axis of the sleeve, the deflection angle of the universal joint is limited by the sleeve, the variable-angle force transmission structure 312 can be prevented from being excessively bent in the transmission process of the bit pressure torque, the transmission of the bit pressure torque is prevented, and therefore the bit pressure torque can be smoothly transmitted.

Or, the variable angle force transmission structure 312 comprises a ball seat 3124 and a ball head 3123, one of the ball head 3123 and the ball seat 3124 is provided with a torque transmission groove 3125, the other of the ball head 3123 and the ball seat 3124 is provided with a torque transmission pin 3126, the torque transmission pin 3126 is rotatably accommodated in the torque transmission groove 3125 to realize torque transmission, a sealing member 3127 is arranged between the torque transmission pin 3126 and the torque transmission groove 3125, and the sealing member 3127 can prevent the drilling fluid in the annular space from channeling with the drilling fluid inside the flexible drill string 3.

In one embodiment of the invention, as shown in fig. 6 and 7, the pressure-bearing hose 32 is a composite pipe, a rubber pipe or a slotted pipe, wherein when the torque transmission string 31 is a slotted pipe, the slots of the slotted pipe are filled with a sealing material.

Further, as shown in fig. 8, when reverse circulation drilling is adopted, the propulsion mechanism 4 is a packing ring 22, the outer diameter of the packing ring is 90% -110% of the outer diameter of the drill bit 1, the packing ring 22 can be attached to the inner wall surface of the borehole or a preset (smaller) gap is kept, and a drilling circulation medium passes through the packing ring 22 after passing through the rotary steering drilling tool and the borehole wall annulus, and further returns through the through flow passage 33 in the flexible drill string 3.

It should be noted that the excluder ring 22 comprises a rubber ring to realize the close contact between the excluder ring and the well wall; during reverse circulation drilling, as the excluder ring 22 occupies the annular space between the rotary steerable drilling tool and the borehole wall, the drilling circulation medium flowing through the excluder ring 22 creates a large resistance that creates a large differential restriction pressure between the upper and lower ends of the excluder ring 22 that drives the drill bit 1 forward. In this embodiment, the packing ring 22 is sleeved outside the bearing body 21, and as a more preferable option, a centering bearing is disposed between the packing ring 22 and the bearing body 21, so that the packing ring may not rotate along with the rotary steering drilling tool, and is used for reducing the wear of the packing ring 22.

In an embodiment of the present invention, as shown in fig. 2 and 4, a gauge structure 212 is connected to the exterior of the bearing body 21, the gauge structure 212 includes a scraper blade or a centralizer, the scraper blade has an external dimension substantially equal to that of the front blade 11, and in a small-sized borehole, the flexible drill string 3 can be ensured to smoothly pass through a short-extremely short radius borehole, and the deep drilling of an extended well section is completed; the centralizer can be used as an effective fulcrum in the rotary guiding process, and the guiding stability and shape can be ensured.

In an embodiment of the present invention, as shown in fig. 2 and fig. 4, the guiding mechanism 211 includes at least three receiving cavities 2111 disposed on the bearing body 21 at intervals along a circumferential direction of the bearing body 21, preferably, the receiving cavities 2111 are disposed at equal intervals, the receiving cavity 2111 is provided with a driving piston 2112 capable of extending and retracting along a radial direction of the bearing body 21, the driving piston 2112 can abut against a borehole wall, specifically, the driving piston 2112 can directly abut against the borehole wall, or indirectly abut against the borehole wall through a pushing member, the extension and retraction of the driving piston 2112 can drive the bearing body 21 to deflect according to a predetermined direction, specifically, by adjusting an extension and retraction amount of each driving piston 2112, a thrust applied to the borehole wall by each driving piston 2112 can be adjusted, the borehole wall will act a reaction force on the bearing body 21 through the driving piston 2112, so that the bearing body 21 drives the drill bit 1 to deflect a certain angle relative to the borehole wall, thereby changing a track of the borehole.

Further, the electrically driven actuator 5 includes a motor 51 and a rotary valve 52, the rotary valve 52 includes a rotary valve disc 521 and a rotary valve seat 522, the rotary valve seat 522 is fixedly connected to the bearing body 21, the rotary valve seat 522 is provided with a plurality of communication holes corresponding to the accommodation cavities 2111 one to one, the rotary valve disc 521 is electrically connected to the motor 51, and the motor 51 can drive the rotary valve disc 521 to rotate relative to the rotary valve seat 522, so that the through holes on the rotary valve seat 522 periodically supply high-pressure drilling fluid to the corresponding accommodation cavities 2111, so as to periodically generate thrust by the driving piston 2112.

In an embodiment of the present invention, as shown in fig. 9, when a lateral branch well is drilled in the interior of a wellbore, the rotary steerable drilling tool further includes a driving drill string 6, the driving drill string 6 drives the rotary steerable drilling tool to implement rotary drilling, the rotary steerable drilling tool is supported by a whipstock 7 and is steered from a main wellbore into the branch wellbore, an anchoring device 8 is disposed below the whipstock 7, the anchoring device 8 can be connected with the inner wall surface of the wellbore to prevent the whipstock 7 from slipping off, the driving drill string 6 is connected with the upper end of a flexible drill string 3, the driving drill string 6 can transmit drilling power to a drill bit 1 through the flexible drill string 3, and the specific structure of the driving drill string 6 is the prior art, and will not be described herein again.

In an embodiment of the present invention, as shown in fig. 1 and 3, the rotary steerable drilling tool further comprises a control sub 9, the control sub 9 is connected between the steering sub 2 and the flexible drill string 3, or the control sub 9 is connected at any position in the flexible drill string 3, or the control sub 9 is connected at the upper end of the flexible drill string 3, since the flexible drill string 3 is advanced by the propelling device, the diameter of the rotary steerable drilling tool should be less than 0.1016m, and therefore, the control sub 9 is inconvenient to enter the branch well bore F along with the rotary steerable drilling tool, and the present invention has the advantage that the control sub 9 does not need to enter the branch well bore F during the construction process, so that the flexibility of the control sub 9 does not need to be considered; a control circuit 91 is arranged in the control pup joint 9, and the control circuit 91 is electrically connected with the electric drive actuator 5 through a jumper line 92 so as to control the drive guide mechanism 211 of the electric drive actuator 5 to realize the rotary guide function.

Furthermore, the rotary steerable drilling tool further comprises a downhole power supply 10, the downhole power supply 10 is connected to the upper end of the flexible drill string 3, the downhole power supply 10 is electrically connected to the control circuit 91, the downhole power supply 10 can be driven by a downhole turbine to generate power, or driven by a downhole screw to generate power, or directly supplied with power by a downhole battery, and the manner of generating power needs to occupy a large amount of space, so that the downhole power supply 10 is arranged above the flexible drill string 3, and the downhole power supply 10 does not enter the branch well bore F during construction, so that the flexibility of the downhole power supply 10 does not need to be considered, and power can be well supplied to the flexible drill string 3 and/or the electrically-driven actuator 5 in the bearing body 21.

It should be noted that, the method for realizing the lateral drilling of the extremely short radius branch well from any position of the main well bore Z is the prior art, and in the prior art, the process of the extremely short radius lateral drilling can guide the well bore track of the extremely short radius well section to a certain extent by depending on the orientation of the whipstock 7 and the included angle between the guiding inclined plane of the whipstock 7 and the Z axis of the main well bore. However, after completing the sidetrack drilling of the very short radius branch, in order to achieve the purpose of maximally contacting the formation, it is necessary to continue to complete the extended well section of the very short radius branch, and the extended displacement and the borehole trajectory precision of the extended well section directly determine the economic benefit of the very short radius branch (including the very short radius well section and the extended well section). Accordingly, the primary purpose of the present invention is to address the problem of wellbore trajectory control for extended runs of very short radius offset intervals, but is not representative of what is described herein for extended runs of very short radius offset intervals only.

In summary, the rotary steerable drilling tool of the present invention, by providing the steering mechanism, the steering mechanism can drive the drill bit to deflect in a predetermined direction under the rotation condition, so as to change the track of the borehole, thereby realizing the short radius directional drilling; by arranging the propelling mechanism, the flexible drill column can be well assisted to advance or push the drill bit to drill, so that small-diameter short-radius guide drilling with certain well hole extension length is realized.

The above description is only an exemplary embodiment of the present invention, and is not intended to limit the scope of the present invention. Any equivalent changes and modifications that can be made by one skilled in the art without departing from the spirit and principles of the invention should fall within the protection scope of the invention. It should be noted that the components of the present invention are not limited to the above-mentioned whole application, and various technical features described in the present specification can be selected to be used alone or in combination according to actual needs, so that the present invention naturally covers other combinations and specific applications related to the invention.

Claims

1. A rotary steerable well tool, wherein the rotary steerable well tool comprises:

a drill bit;

2. The rotary steerable drilling tool of claim 1,

the propulsion mechanism comprises at least two reverse nozzles arranged at intervals along the circumferential direction of the bearing body, and inlets of the reverse nozzles are communicated with a through flow passage in the flexible drill string.

3. The rotary steerable drilling tool of claim 1,

the propulsion mechanism comprises a drainage nozzle and a closed structure, the closed structure is provided with a throat, the drainage nozzle is arranged on the lower portion of the throat, and the throat is communicated with a through flow channel in the flexible drill string through the drainage nozzle.

4. The rotary steerable drilling tool of claim 1,

the torque transmission tandem includes a plurality of torque transmission nipple joints that from top to bottom connect gradually, adjacent two can the pivoted connection through variable angle biography power structure between the torque transmission nipple joint, is located the below the torque transmission nipple joint with it meets to bear the body.

5. The rotary steerable drilling tool of claim 4,

the deflection limit between any two torque transmission short joints is more than 2 degrees.

6. The rotary steerable drilling tool of claim 4,

the length of the torque transmission nipple is less than or equal to 5 times of the diameter of the bearing body.

7. The rotary steerable drilling tool of claim 4,

the length of the torque transmission short section is 30% -300% of the diameter of the bearing body.

8. The rotary steerable drilling tool of claim 4,

the variable-angle force transmission structure comprises a universal joint and a sleeve sleeved outside the universal joint, a gap is formed between the sleeve and the universal joint to form a deflection space, and the universal joint can deflect 0.5-15 degrees in the deflection space relative to the axis of the sleeve.

9. The rotary steerable drilling tool of claim 4,

the variable-angle force transmission structure comprises a ball seat and a ball head, wherein one of the ball head and the ball seat is provided with a torque transmission groove, the other of the ball head and the ball seat is provided with a torque transmission pin, and the torque transmission pin can be rotatably accommodated in the torque transmission groove.

10. The rotary steerable drilling tool of claim 1,

the pressure-bearing hose is a composite material pipe, a rubber pipe or a slit pipe filled with sealing materials.

11. The rotary steerable drilling tool of claim 1,

the external connection who bears the weight of the body has the gauge structure, the gauge structure includes scraping wing of a knife or centralizer.

12. The rotary steerable drilling tool of claim 1,

the guiding mechanism comprises at least three edges, the circumferential interval of the bearing body is arranged in the containing cavity on the bearing body, the containing cavity is internally provided with a driving piston which can stretch along the radial direction of the bearing body, the driving piston can be abutted against the well wall, and the stretching of the driving piston can drive the bearing body to deflect according to a preset direction.

13. The rotary steerable drilling tool of claim 12,

the electric drive actuator comprises a motor and a rotary valve, the rotary valve comprises a rotary valve disc and a rotary valve seat, the rotary valve seat is fixedly connected with the bearing body, the rotary valve seat is provided with a plurality of communication holes which are in one-to-one correspondence with the accommodating cavities respectively, the rotary valve disc is electrically connected with the motor, and the motor can drive the rotary valve disc to rotate relative to the rotary valve seat.

14. The rotary steerable drilling tool of claim 1,

when reverse circulation drilling is adopted, the propelling mechanism is an isolation ring, the outer diameter of the isolation ring is 90% -110% of the outer diameter of the drill bit, and the isolation ring can be attached to the inner wall surface of a well hole or keep a preset gap.

15. The rotary steerable drilling tool of any of claims 1-14,

the rotary steering drilling tool further comprises a control short section, the control short section is connected between the guide section and the flexible drill string, or the control short section is connected to any position in the flexible drill string, or the control short section is connected to the upper end of the flexible drill string, a control circuit is arranged in the control short section, and the control circuit is electrically connected with the electric drive actuator through a jumper circuit.

16. The rotary steerable drilling tool of claim 15,

the rotary steerable drilling tool also includes a downhole power source connected to the upper end of the flexible drill string, the downhole power source being electrically connected to the control circuit.