Downhole string rotation control switch

Abstract

The invention provides an underground tubular column rotation control switch which comprises an upper connector, and the upper end of the upper connector is connected with an upper drill rod. The lower end of the main shaft is connected with the lower drill rod; wherein the upper joint is connected with the main shaft in a sleeving manner, and a rotary switch assembly is arranged between the upper joint and the main shaft; when the pressure in the pipe of the upper joint is smaller than or equal to a certain value, the rotary switch assembly is in a first state and is connected with the upper joint and the main shaft, so that the upper joint can drive the main shaft to rotate; and when the pressure in the upper joint pipe is greater than a certain value, the rotary switch assembly is in a second state, so that the upper joint is separated from the main shaft.

Description

TECHNICAL FIELD

[0001] The present application relates to a downhole pipe string rotation control switch suitable for long horizontal section horizontal wells and ocean extended reach wells commonly used in unconventional oil and gas field development. BACKGROUND

[0002] In order to solve the shortcomings of screw drill sliding drilling, various technologies have been developed at home and abroad: using advanced rotary steering tools, since the drill string can be rotated during steering, rotary steering overcomes the shortcomings of sliding steering technology, the drilling pressure is transmitted smoothly, the mechanical drilling speed is high, and the wellbore quality is good.

[0003] Under the premise of maintaining the ability of well trajectory control, through the research of large bending angle screw composite drilling technology, the proportion of sliding drilling rig is reduced, and the drilling speed is improved; the configuration tools and measures of variable diameter stabilizer and other screw steering tools are researched and applied, and the performance of conventional steering tools is improved as much as possible;

[0004] The top drive rotary oscillation drill tool technology is also a technology being researched and applied, and its technical principle is: by changing the top drive program, when sliding drilling, the top drive first rotates in a certain number of turns, and then reverses in the same number of turns, and the above process is continuously repeated, so that the drill string of a certain length is subjected to continuous forward and reverse oscillation, which can reduce the friction between the drill string and the well wall, and the number of forward and reverse turns is limited within a certain range.

[0005] The Chinese patent document "a downhole pipe string rotation control switch" (ZL201620363357.0) proposes a switch tool controlled by drilling fluid, the main problem is that the transmission structure is very complex, the torque that can be borne by the bolt structure is small, and the axial thrust that can be borne by the thrust bearing is small.

[0006] The Chinese patent document "upward rotation and downward sliding drilling friction reduction and torque reduction tool" (CN201220454297) proposes a tool for reducing resistance, which uses an upward lifting and downward placing control method, and there is a problem of difficult control in the actual drilling process due to severe axial vibration; and the design of the transmission part is not involved, and the short section that can bear the drilling pressure level axial force will be quickly worn out, so the practicality is poor. SUMMARY

[0007] In view of the above technical problems existing in the prior art, the present application proposes a downhole pipe string rotation control switch which can rotate the drill string during sliding drilling to smoothly transmit the drilling pressure and effectively control the tool face.

[0008] In addition, the downhole pipe string rotation control switch is used in cooperation with the screw drill, and the drill string can rotate in the positive direction during the sliding drilling of the screw drill, solving the problems of sliding drilling pressure and low mechanical drilling speed.

[0009] The application provides a downhole pipe string rotation control switch, comprising:

[0010] an upper joint, an upper end of the upper joint being connected with an upper drill pipe; and

[0011] a main shaft, a lower end of the main shaft being connected with a lower drill pipe;

[0012] wherein, the upper joint and the main shaft are connected in a sleeve manner, and a rotation switch assembly is arranged between the upper joint and the main shaft;

[0013] when the internal pipe pressure of the upper joint is less than or equal to a certain value, the rotation switch assembly is in a first state, which connects the upper joint and the main shaft, so that the upper joint can drive the main shaft to rotate;

[0014] when the internal pipe pressure of the upper joint is greater than a certain value, the rotation switch assembly is in a second state, which separates the upper joint and the main shaft.

[0015] Further improvement of the application is that a stepped groove is arranged on the inner wall of the upper joint, and the rotation switch assembly is arranged in the stepped groove.

[0016] Further improvement of the application is that a locking nut is arranged at the upper end of the main shaft, and an external spline is arranged on the side wall of the locking nut.

[0017] an internal spline is arranged on the rotation switch assembly and matched with the external spline; the internal spline is configured to be connected with or separated from the external spline under the action of the internal pipe pressure.

[0018] Further improvement of the application is that a thrust bearing group is further arranged between the upper joint and the main shaft.

[0019] Further improvement of the application is that the number of the stepped grooves is at least two, and the grooves are arranged on the circumference of the inner wall of the upper joint.

[0020] The stepped groove comprises a first groove body close to the central axis of the upper joint and a second groove body away from the central axis of the upper joint, the width of the first groove body is greater than that of the second groove body, and a stepped structure is formed between the first groove body and the second groove body.

[0021] Further improvement of the application is that a through hole is further arranged in the second groove body and communicated with the outside of the upper joint.

[0022] Further improvement of the application is that the rotation switch assembly comprises a control block, the internal end of the control block is provided with the internal spline, and the external end of the control block is provided with a sliding rod.

[0023] The control block is slidably arranged in the first groove, and the sliding rod is slidably arranged in the through hole.

[0024] The further improvement of the present application is that the rotary switch assembly further comprises a spring arranged in the second groove.

[0025] In the first state, the spring pushes the control block to tightly contact the locking nut; when the pressure in the pipe increases to a certain value, the pressure in the pipe pushes the control block to compress the spring, so as to separate from the locking nut and be in the second state.

[0026] The further improvement of the present application is that the inner part of the upper joint is further provided with an inner step, the thrust bearing set is arranged in an annular groove below the inner step, and an adjusting washer is arranged in the annular groove to adjust the position of the thrust bearing set.

[0027] The further improvement of the present application is that the lower end of the lower joint is connected with a lower nut through a taper buckle.

[0028] The further improvement of the present application is that the main shaft is provided with a main shaft step.

[0029] The inner ring of the upper end of the thrust bearing set is defined by the locking nut, and the outer ring is defined by the inner step and the adjusting washer.

[0030] The inner ring of the lower end of the thrust bearing set is defined by the main shaft step, and the outer ring is defined by the lower nut.

[0031] Compared with the prior art, the present application has the following advantages:

[0032] The downhole pipe string rotary control switch can rotate the drill string to smoothly transmit the drilling pressure during sliding drilling, and can effectively control the tool on the tool face. In addition, the downhole pipe string rotary control switch is used in cooperation with the screw drill, and the drill string can be rotated in the positive direction during sliding drilling of the screw drill, thereby solving the problems of sliding drilling pressure bearing and low mechanical drilling speed.

[0033] According to the downhole pipe string rotary control switch, when the switch is opened, the rotary table or the top drive can only drive the drill pipe above the switch to rotate, and the drill pipe below the switch, the non-magnetic drill collar and the screw drill remain in a non-rotating state under the action of friction. In this way, the rotation of the drill string above the switch can be maintained under the premise of maintaining the well trajectory control ability. Generally, the drill string above the switch accounts for more than 80% of the total length of the drill string, so the axial drilling pressure transmission resistance can be greatly reduced, and the mechanical drilling speed can be improved by 2-3 times. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings, in which:

[0035] Figure 1 FIG2 is a schematic structural diagram of a downhole tubular string rotation control switch according to an embodiment of the present invention;

[0036] Figure 2 FIG2 is a schematic structural diagram of a rotary switch assembly according to an embodiment of the present invention, showing the structure in a first state;

[0037] Figure 3 FIG2 is a schematic structural diagram of a rotary switch assembly according to an embodiment of the present invention, showing the structure in a second state;

[0038] The drawings are not drawn to scale.

[0039] The meanings of the reference numerals in the accompanying drawings are as follows:

[0040] 1. Upper joint, 2. Spindle, 3. Rotary switch assembly, 4. Thrust bearing group, 11. Stepped groove, 12. Inner step, 13. Taper buckle, 14. Lower nut, 15. Adjusting washer, 16. First slot body, 17. Second slot body, 18. Through hole, 21. Locking nut, 22. Spindle step, 23. External spline, 31. Control stop, 32. Internal spline, 33. Sliding rod, 34. Spring. DETAILED DESCRIPTION

[0041] To make the technical solutions and advantages of the present invention more clearly understood, exemplary embodiments of the present invention are further described in detail below with reference to the accompanying drawings. It should be understood that the described embodiments are only a portion of the embodiments of the present invention, and are not exhaustive. Furthermore, the embodiments and features of the embodiments of the present invention may be combined with each other unless there is a conflict.

[0042] In order to solve the shortcomings of sliding drilling of screw drilling tools, various technologies have been developed at home and abroad: using advanced rotary steering tools, since the drill string can be rotated during guidance, rotary steering overcomes the shortcomings of sliding steering technology, with smooth bit pressure transmission, high mechanical drilling speed and good wellbore quality.

[0043] While maintaining the ability to control the wellbore trajectory, the research on large-angle screw composite drilling technology can reduce the proportion of sliding drilling rigs and increase drilling speed. The research and application of screw guide drilling tools such as variable diameter stabilizers and other configuration tools and measures can maximize the performance of conventional guide drilling tools.

[0044] The top drive rotation oscillation drill tool technology is also a technology being researched and applied at present, and its technical principle is: by changing the top drive program, when sliding drilling, the top drive first rotates forward for a certain number of turns, and then reverses for the same number of turns, and the above process is continuously repeated, so that the drill string of a certain length is subjected to continuous forward and reverse oscillation, which can reduce the friction between the drill string and the well wall, and the forward and reverse number of turns is limited within a certain range.

[0045] To solve the above problems, the application provides a downhole pipe string rotation control switch, which can rotate the drill string to smoothly transfer the drilling pressure during sliding drilling and effectively control the tool face of the tool.

[0046] In the embodiment shown in FIG. Figure 1 The downhole pipe string rotation control switch comprises:

[0047] An upper joint 1, the upper end of the upper joint 1 being connected with an upper drill pipe; in the embodiment, the upper joint 1 is a cylindrical or tubular structure.

[0048] A main shaft 2, the lower end of the main shaft 2 being connected with a lower drill pipe, the lower drill pipe being connected with a non-magnetic drill collar, a screw drill and a drill bit; in the embodiment, the main shaft 2 is a tubular structure.

[0049] The upper joint 1 and the main shaft 2 are connected in a sleeved manner, and a rotation switch assembly 3 is arranged between the upper joint 1 and the main shaft 2; when the pipe internal pressure of the upper joint 1 is less than or equal to a certain value, the rotation switch assembly 3 is in a first state, which connects the upper joint 1 and the main shaft 2, so that the upper joint 1 can drive the main shaft 2 to rotate; when the pipe internal pressure of the upper joint 1 is greater than a certain value, the rotation switch assembly 3 is in a second state, which separates the upper joint 1 from the main shaft 2.

[0050] When the downhole pipe string rotation control switch according to the embodiment is used, the downhole pipe string rotation control switch is placed at a certain position above the screw drill, and the length between the downhole pipe string rotation control switch and the screw drill needs to be determined according to the specifications of the screw drill and the drill string, and the principle of determination is that the friction torque generated between the drill string string below the downhole pipe string rotation control switch (including the screw drill) and the well wall is not less than the counter torque of the screw drill. The specific drill string structure is in turn a drill pipe, the downhole pipe string rotation control switch, a drill pipe, a non-magnetic drill collar, a screw drill and a drill bit from top to bottom, and based on the specifications of common screw drills and drill pipes, the length of the drill string below the switch is generally 200-400 m.

[0051] After the downhole pipe string rotation control switch is added in the drill string, the switch is opened or closed according to the drilling needs, and when the switch is closed, the overall drill string structure is integrated, and rotates or does not rotate simultaneously from top to bottom. When the switch is opened, the rotary table or top drive can only drive the drill pipe above the switch to rotate, and the drill pipe below the switch, the non-magnetic drill collar and the screw drill tool remain in a non-rotating state under the action of friction. In this way, the rotation of the drill string above the switch can be maintained while maintaining the ability to control the wellbore trajectory, and in general, the drill string above the switch accounts for more than 80% of the total length of the drill string, so the axial drilling pressure transmission resistance can be greatly reduced, and the rate of penetration can be improved by 2-3 times.

[0052] In one embodiment, a stepped groove 11 is arranged on the inner wall of the upper joint 1, and the rotation switch assembly 3 is arranged in the stepped groove 11.

[0053] In one embodiment, a locking nut 21 is arranged at the upper end of the main shaft 2, an outer spline 23 is arranged on the side wall of the locking nut 21, and an inner spline 32 that matches the outer spline 23 is arranged on the rotation switch assembly 3; the inner spline 32 is configured to be connected or separated from the outer spline 23 under the action of the pressure in the pipe.

[0054] In the downhole pipe string rotation control switch according to the embodiment, the position of the inner spline 32 is affected by the pressure in the pipe, when the pressure in the pipe of the upper joint 1 is less than or equal to a certain value, the rotation switch assembly 3 is in a first state, the pressure in the pipe is not enough to move the inner spline 32 of the rotation switch assembly 3, at this time, the inner spline 32 of the rotation switch assembly 3 is engaged with the outer spline 23 of the locking nut 21, and the rotation of the upper joint 1 can be transmitted to the outer spline 23 and the locking nut 21 through the rotation switch assembly 3 and the inner spline 32, so that the torque of the upper drill pipe is transmitted to the lower drill pipe to drive the lower drill tool to rotate.

[0055] When the pressure in the pipe of the upper joint 1 is greater than a certain value, the rotation switch assembly 3 is in a second state, the pressure in the pipe increases and pushes the inner spline 32 of the rotation switch assembly 3 to move, at this time, the inner spline 32 of the rotation switch assembly 3 is separated from the outer spline 23 of the locking nut 21, and the rotation of the upper joint 1 will not drive the main shaft 2 to rotate, so that the torque of the upper drill pipe cannot be transmitted to the lower drill pipe.

[0056] In one embodiment, a thrust bearing set 4 is further arranged between the upper joint 1 and the main shaft 2, the function of the thrust bearing is to connect the upper joint 1 and the main shaft 2, so that the upper joint 1 and the main shaft 2 are connected together and can also rotate relative to each other, and since the bearing set is adopted, an axial thrust of up to 100 tons can be borne, which is used to transmit the drilling pressure during drilling.

[0057] In one embodiment, the number of the stepped grooves 11 is at least two, which are arranged on the inner wall of the upper joint 1 in the circumferential direction.

[0058] In Figure 1 In the illustrated embodiment, the number of the stepped grooves is two, which are arranged oppositely inside the upper joint 1. The number of the stepped grooves 11 can also be three, four or more.

[0059] The stepped grooves 11 are internally provided with a stepped structure, which includes two groove bodies, wherein the groove body close to the central axis of the upper joint 1 is a first groove body 16, and the groove body away from the central axis of the upper joint 1 is a second groove body 17. The width of the first groove body 16 is greater than the width of the second groove body 17 (if the groove body is a circular groove, the width here is the diameter), and a stepped structure is formed between the first groove body 16 and the second groove body 17 due to the different widths of the two groove bodies.

[0060] In one embodiment, the second groove body 17 is further provided with a through hole 18, which communicates the inside and outside of the upper joint 1.

[0061] In one embodiment, the rotary switch assembly 3 includes a control block 31, which is a block structure. The inner end of the control block 31 is provided with the inner spline 32, and the outer end is provided with a sliding rod 33, wherein the inner end is the end close to the central axis of the upper joint 1, and the outer end is the end away from the central axis of the upper joint 1.

[0062] The control block 31 is slidingly arranged in the first groove body 16, and the sliding rod 33 is slidingly arranged in the through hole 18.

[0063] In the downhole string rotation control switch according to the embodiment, the thickness of the control block 31 is less than the thickness of the first groove body 16, so that the control block 31 can slide in the first groove body 16. The inner end of the control block 31 is provided with the inner spline 32, which can cooperate with the outer spline 23 of the locking nut 21.

[0064] When the rotary switch assembly 3 is in the first state, the control block 31 is in the first position, and at this time, the inner spline 32 of the control block 31 cooperates with the outer spline 23 of the locking nut 21.

[0065] When the rotary switch assembly 3 is in the second state, the control block 31 is in the second position, and at this time, the inner spline 32 of the control block 31 is separated from the outer spline 23 of the locking nut 21.

[0066] In one embodiment, the rotary switch assembly 3 further includes a spring 34, which is arranged in the second groove body 17.

[0067] In the first state, the spring 34 pushes the control block 31 to adhere to the locking nut 21; when the pressure in the pipe increases to a certain value, the pressure in the pipe pushes the control block 31 to compress the spring 34, so as to separate from the locking nut 21 and be in the second state.

[0068] In the downhole pipe string rotation control switch according to the embodiment, the spring 34 provides an inward pushing force for the control block 31, so that the control block 31 can be in the first position and the inner spline 32 is matched with the outer spline 23. When the pressure in the pipe of the upper joint 1 is less than or equal to a certain value, the rotation switch assembly 3 is in the first state; when the pressure in the pipe of the upper joint 1 is greater than a certain value, the rotation switch assembly 3 is in the second state; wherein the pressure value in the pipe is related to the elastic force of the spring 34, and the opening pressure can be determined by replacing or selecting the elastic force of the spring 34.

[0069] In an embodiment, the inside of the upper joint 1 is further provided with an inner step 12, which is arranged below the stepped groove 11. There is a circular groove at the inside of the upper joint 1, and the upper end of the circular groove forms the inner step 12.

[0070] The thrust bearing set 4 is arranged in the circular groove below the inner step 12, and the circular groove is further provided with an adjusting washer 15 for adjusting the position of the thrust bearing set 4.

[0071] According to the size and position of the thrust bearing set 4, the adjusting washer 15 can be adjusted and matched by increasing or decreasing the number of adjusting washers 15.

[0072] In an embodiment, the lower end of the lower joint is connected with a lower nut 14 through a taper buckle 13.

[0073] In an embodiment, the main shaft 2 is provided with a main shaft step 22;

[0074] The inner ring of the upper end of the thrust bearing set 4 is defined by the locking nut 21, and the outer ring is defined by the inner step 12 and the adjusting washer 15;

[0075] The inner ring of the lower end of the thrust bearing set 4 is defined by the main shaft step 22, and the outer ring is defined by the lower nut 14.

[0076] The inner side of the thrust bearing is defined on the main shaft 2, and the outer side is defined on the upper joint 1.

[0077] The specific embodiments will be described below.

[0078] Embodiment 1

[0079] A downhole pipe string rotation control switch, comprising:

[0080] An upper joint 1, an upper end of the upper joint 1 is connected with an upper drill pipe; in the embodiment, the upper joint 1 is a cylindrical or tubular structure.

[0081] A main shaft 2, a lower end of the main shaft 2 is connected with a lower drill pipe, the lower drill pipe is connected with a non-magnetic drill collar, a screw drill and a drill bit. In the embodiment, the main shaft 2 is a tubular structure.

[0082] The upper joint 1 and the main shaft 2 are connected in a sleeved manner, and a rotation switch assembly 3 is arranged between the upper joint 1 and the main shaft 2; when the pressure in the pipe of the upper joint 1 is less than or equal to a certain value, the rotation switch assembly 3 is in a first state, which connects the upper joint 1 and the main shaft 2, so that the upper joint 1 can drive the main shaft 2 to rotate; when the pressure in the pipe of the upper joint 1 is greater than a certain value, the rotation switch assembly 3 is in a second state, which separates the upper joint 1 from the main shaft 2.

[0083] A stepped groove 11 is arranged on the inner wall of the upper joint 1, and the rotation switch assembly 3 is arranged in the stepped groove 11.

[0084] An upper end of the main shaft 2 is provided with a locking nut 21, an outer spline 23 is arranged on the side wall of the locking nut 21, and an inner spline 32 is arranged on the rotation switch assembly 3 and matched with the outer spline 23; the inner spline 32 is configured to be connected or separated from the outer spline 23 under the action of the pressure in the pipe.

[0085] The position of the inner spline 32 is affected by the pressure in the pipe; when the pressure in the pipe of the upper joint 1 is less than or equal to a certain value, the rotation switch assembly 3 is in the first state, and the pressure in the pipe is not enough to drive the inner spline 32 of the rotation switch assembly 3 to move, at this time, the inner spline 32 of the rotation switch assembly 3 is engaged with the outer spline 23 of the locking nut 21, the rotation of the upper joint 1 can be transmitted to the outer spline 23 and the locking nut 21 through the rotation switch assembly 3 and the inner spline 32, so that the torque of the upper drill pipe is transmitted to the lower drill pipe to drive the lower drill tool to rotate.

[0086] When the pressure in the pipe of the upper joint 1 is greater than a certain value, the rotation switch assembly 3 is in the second state, and the pressure in the pipe increases to drive the inner spline 32 of the rotation switch assembly 3 to move, at this time, the inner spline 32 of the rotation switch assembly 3 is separated from the outer spline 23 of the locking nut 21, the rotation of the upper joint 1 cannot drive the main shaft 2 to rotate, so that the torque of the upper drill pipe cannot be transmitted to the lower drill pipe.

[0087] The upper joint 1 and the main shaft 2 are also provided with a thrust bearing group 4, which connects the upper joint 1 and the main shaft 2, so that the upper joint 1 and the main shaft 2 are connected together and can also rotate relative to each other. Since the bearing group is adopted, an axial thrust of up to 100 tons can be borne for transmitting the drilling pressure during drilling.

[0088] The number of the stepped grooves 11 is at least two, which are arranged on the inner wall of the upper joint 1 in a circumferential direction.

[0089] The stepped grooves are two, which are oppositely arranged in the interior of the upper joint 1.

[0090] The stepped grooves 11 are internally provided with a stepped structure, which includes two groove bodies, wherein the groove body close to the central axis of the upper joint 1 is a first groove body 16, and the groove body away from the central axis of the upper joint 1 is a second groove body 17. The width of the first groove body 16 is greater than the width of the second groove body 17 (if the groove body is a circular groove, the width here is the diameter), and a stepped structure is formed between the first groove body 16 and the second groove body 17 due to the different widths of the two groove bodies.

[0091] The second groove body 17 is also provided with a through hole 18, which communicates the interior and the exterior of the upper joint 1.

[0092] The rotary switch assembly 3 includes a control block 31, which is a block structure. The inner end of the control block 31 is provided with the inner spline 32, and the outer end is provided with a sliding rod 33. The inner end is close to the central axis of the upper joint 1, and the outer end is away from the central axis of the upper joint 1.

[0093] The control block 31 is slidably arranged in the first groove body 16, and the sliding rod 33 is slidably arranged in the through hole 18.

[0094] The thickness of the control block 31 is less than the thickness of the first groove body 16, so that the control block 31 can slide in the first groove body 16. The inner end of the control block 31 is provided with the inner spline 32, which can cooperate with the outer spline 23 of the locking nut 21.

[0095] When the rotary switch assembly 3 is in the first state, the control block 31 is in the first position, and at this time, the inner spline 32 of the control block 31 cooperates with the outer spline 23 of the locking nut 21.

[0096] When the rotary switch assembly 3 is in the second state, the control block 31 is in the second position, and at this time, the inner spline 32 of the control block 31 is separated from the outer spline 23 of the locking nut 21.

[0097] The rotating switch assembly 3 further comprises a spring 34, which is arranged in the second groove 17;

[0098] In the first state, the spring 34 pushes the control block 31 to adhere to the locking nut 21; when the pressure in the pipe increases to a certain value, the pressure in the pipe pushes the control block 31 to compress the spring 34, so as to separate from the locking nut 21 and be in the second state.

[0099] The spring 34 provides an inward pushing force for the control block 31, so that it can be in the first position and the inner spline 32 is matched with the outer spline 23. When the pressure in the pipe of the upper joint 1 is less than or equal to a certain value, the rotating switch assembly 3 is in the first state; when the pressure in the pipe of the upper joint 1 is greater than a certain value, the rotating switch assembly 3 is in the second state; wherein the pressure value in the pipe is related to the spring force of the spring 34, and the opening pressure can be determined by replacing or selecting the spring force of the spring 34.

[0100] The inner part of the upper joint 1 is further provided with an inner step 12, which is arranged below the stepped groove 11. The inner part of the upper joint 1 starts with a circular groove, and the upper end of the circular groove forms the inner step 12.

[0101] The thrust bearing set 4 is arranged in the circular groove below the inner step 12, and the circular groove is further provided with an adjusting washer 15 for adjusting the position of the thrust bearing set 4.

[0102] According to the size and position of the thrust bearing set 4, the number of adjusting washers 15 can be increased or decreased to adjust and match.

[0103] The lower end of the lower joint is connected with a lower nut 14 through a taper buckle 13.

[0104] The main shaft 2 is provided with a main shaft step 22;

[0105] The inner ring of the upper end of the thrust bearing set 4 is defined by the locking nut 21, and the outer ring is defined by the inner step 12 and the adjusting washer 15;

[0106] The inner ring of the lower end of the thrust bearing set 4 is defined by the main shaft step 22, and the outer ring is defined by the lower nut 14.

[0107] The inner side of the thrust bearing is defined on the main shaft 2, and the outer side is defined on the upper joint 1.

[0108] In use of the downhole pipe string rotation control switch according to the embodiment, first, the length of the drill string below the downhole pipe string rotation control switch is calculated according to the drill string specification, the friction coefficient between the drill string and the well wall, and the screw drill anti-torque. The downhole pipe string rotation control switch is placed in the drill string, and the drill string is lowered to the bottom of the well. According to the drilling needs, if composite drilling is needed, i.e. the screw drill also needs to rotate, the switch is closed by reducing the drilling fluid discharge. The rotary table or top drive is started to drive the drill string to rotate, and the drill pipe, non-magnetic drill collar and screw drill rotate together to achieve the purpose of composite drilling.

[0109] If sliding drilling is needed, i.e. the screw drill does not rotate, the switch is opened by increasing the drilling fluid discharge. The rotary table or top drive is started to drive the drill string above the switch to rotate, and the drill pipe, non-magnetic drill collar and screw drill below the switch are affected by the screw drill anti-torque and friction torque. Since the friction torque is greater than the screw drill anti-torque, the pipe string below the switch is in a non-rotating state, and the screw drill tool face remains stable, which can achieve the goal of well trajectory control. Since the drill string above the switch can rotate, the rotation overcomes most of the axial friction, and the drilling pressure can be smoothly transmitted, and the rate of penetration is greatly improved.

[0110] After a period of drilling, the well trajectory design goal has been reached, and stable inclination drilling is needed, then the switch can be closed by reducing the drilling fluid discharge to switch to the composite drilling state.

[0111] It should be understood that the embodiments disclosed in the present application are not limited to the specific structure, processing steps or materials disclosed herein, but should extend to equivalent alternatives of these features understood by those skilled in the relevant art. It should also be understood that the terms used herein are for the purpose of describing specific embodiments only and are not meant to be limiting.

[0112] In the description of the present application, unless otherwise specified, the meaning of "a plurality of" is two or more; the orientations or positional relationships indicated by the terms "upper", "lower", "left", "right", "inner", "outer", "front end", "rear end", "head", "tail" and the like are based on the orientations or positional relationships shown in the drawings, and are only for the purpose of facilitating the description of the present application and simplifying the description, and are not intended to indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application. In addition, the terms "first", "second", "third" and the like are only for the purpose of description and cannot be understood as indicating or implying relative importance.

[0113] In the description of the present application, it is necessary to point out that, unless otherwise explicitly specified and limited, the terms "connected", "connected" should be understood broadly, for example, can be fixedly connected, can also be detachably connected, or integrally connected; can be mechanically connected, can also be electrically connected; can be directly connected, can also be indirectly connected through an intermediate medium. For those of ordinary skill in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0114] Certain terms are used throughout the present application to refer to particular system components. As one skilled in the art will appreciate, the same component can be referred to by different names and can be used according to different protocols, but as would be accepted by those skilled in the art, the different names and protocols do not affect the nature of the component. The phrase "one embodiment" or "an embodiment" appearing in the specification means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the application. Therefore, the appearance of the phrase "one embodiment" or "an embodiment" throughout the specification does not necessarily refer to the same embodiment.

[0115] The embodiments of the present application are given for the purpose of illustration and description, and are not intended to be exhaustive or to limit the application to the disclosed form. Many modifications and variations will be apparent to those of ordinary skill in the art. The embodiments are chosen and described in order to best explain the principles of the application and its practical application, and to enable others skilled in the art to understand the application for various embodiments with various modifications as are suited to the particular use contemplated.

[0116] Although the preferred embodiments of the present application have been described, those skilled in the art can make further changes and modifications to the embodiments once they know the basic inventive concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and / or modifications falling within the scope of the present application, and the changes and / or modifications made to the embodiments according to the present application should be covered within the scope of protection of the present application.

Claims

1. A downhole string rotation control switch, characterized by, The utility model relates to a drilling tool upper joint and main shaft connection structure, which comprises: an upper joint (1) having an upper end connected to an upper drill rod; and a main shaft (2) having a lower end connected to a lower drill rod; wherein the upper joint (1) and the main shaft (2) are connected in a sleeved manner, and a rotary switch assembly (3) is arranged between the upper joint (1) and the main shaft (2); when the pressure in the pipe of the upper joint (1) is less than or equal to a certain value, the rotary switch assembly (3) is in a first state, which connects the upper joint (1) and the main shaft (2), so that the upper joint (1) can drive the main shaft (2) to rotate; when the pressure in the pipe of the upper joint (1) is greater than a certain value, the rotary switch assembly (3) is in a second state, which separates the upper joint (1) from the main shaft (2).

2. The downhole string rotational control switch of claim 1, wherein, A stepped groove (11) is arranged on the inner wall of the upper joint (1), and the rotary switch assembly (3) is arranged in the stepped groove (11).

3. A downhole string rotation control switch according to claim 2, characterised in that, An upper end of the main shaft (2) is provided with a locking nut (21), and an outer spline (23) is arranged on the side wall of the locking nut (21); an inner spline (32) is arranged on the rotary switch assembly (3) and matched with the outer spline (23); the inner spline (32) is configured to be connected or separated from the outer spline (23) under the action of the pressure in the pipe.

4. The downhole string rotational control switch of claim 3, wherein, A thrust bearing group (4) is further arranged between the upper joint (1) and the main shaft (2).

5. The downhole string rotational control switch of claim 4, wherein, The number of the stepped grooves (11) is at least two, and they are arranged on the circumference of the inner wall of the upper joint (1); the stepped grooves (11) comprise a first groove body (16) close to the central axis of the upper joint (1) and a second groove body (17) away from the central axis of the upper joint (1); the width of the first groove body (16) is greater than that of the second groove body (17), and a stepped structure is formed between the first groove body (16) and the second groove body (17).

6. The downhole string rotational control switch of claim 5, wherein, A through hole (18) communicating with the outside of the upper joint (1) is further arranged in the second groove body (17).

7. A downhole string rotation control switch according to claim 6, characterised in that, The rotary switch assembly (3) comprises a control block (31), the inner end of the control block (31) is provided with the inner spline (32), and the outer end is provided with a sliding rod (33); wherein the control block (31) is slidingly arranged in the first groove body (16), and the sliding rod (33) is slidingly arranged in the through hole (18).

8. The downhole string rotational control switch of claim 7, wherein, The rotary switch assembly (3) further comprises a spring (34) arranged in the second groove body (17); in the first state, the spring (34) pushes the control block (31) to tightly contact the locking nut (21); when the pressure in the pipe increases to a certain value, the control block (31) is pushed by the pressure in the pipe to compress the spring (34), so as to be separated from the locking nut (21) and be in the second state.

9. A downhole string rotation control switch according to claim 8, characterised in that, The upper joint (1) is internally provided with an inner step (12), the thrust bearing set (4) is arranged in a ring groove below the inner step (12), and an adjusting washer (15) is arranged in the ring groove to adjust the position of the thrust bearing set (4).

10. The downhole string rotational control switch of claim 9, wherein, The lower end of the lower joint is connected with a lower nut (14) through a taper buckle (13).

11. The downhole string rotational control switch of claim 10, wherein, The main shaft (2) is provided with a main shaft step (22); The inner ring of the upper end of the thrust bearing set (4) is defined by a locking nut (21), and the outer ring is defined by the inner step (12) and the adjusting washer (15); The inner ring of the lower end of the thrust bearing set (4) is defined by the main shaft step (22), and the outer ring is defined by the lower nut (14).

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