Rotary sliding directional tool

Abstract

The application provides a rotary sliding orientation tool, which comprises an orientation housing, a core shaft, a measuring system installed on the orientation housing and located close to a drill bit, and a rotation control system of the orientation housing, wherein the upper end of the core shaft is connected with a drill rod, the lower end of the core shaft is connected with the drill bit, the drill rod drives the drill bit to rotate and drill by the core shaft, and near-bit measurement is conducted by the measuring system, in a first state, the drilling pressure is greater than a predetermined value, the core shaft is bent to approach the inner wall of the orientation housing and generate a friction force by the rotation control system of the orientation housing, and the orientation housing can be rotated by the friction force, so that composite drilling is conducted or the tool face is adjusted, and in a second state, the drilling pressure is less than the predetermined value, the orientation housing is separated from the core shaft by the rotation control system of the orientation housing, and the tool face is kept unchanged under the action of the friction force of the well wall, so that the orientation housing can conduct directional drilling when the drill string rotates.

Description

Technical Field

[0001] This invention belongs to the field of oil and gas extraction technology, and specifically relates to a rotary sliding directional tool. Background Technology

[0002] In existing technologies, directional and horizontal wells primarily utilize screw drill strings for wellbore trajectory control. Current screw-guided wells use a curved outer casing connected to the drill string, with the mandrel driven by hydraulic energy. During directional drilling with screw drill strings, the entire drill string must maintain the stability of the screw drill string tool face, resulting in significant axial friction between the drill string and the wellbore. This is particularly problematic for long horizontal sections and extended reach wells, where the high axial friction leads to poor pressure on the drill string (PBT) transmission and low rate of drilling (RWD). To address the low RWD associated with sliding directional drilling using screw drill strings, various technologies have been developed both domestically and internationally. The main approach is to rotate the drill string to reduce friction and increase RWD.

[0003] Currently, the most advanced technology is the rotary steerable tool. Rotary steerable tools can rotate the drill string while effectively controlling the wellbore trajectory, overcoming the shortcomings of sliding steerable technology. This results in smooth pressure on the drill bit, high mechanical drilling speed, and good wellbore quality. However, because rotary steerable tools are electromechanical-hydraulic integrated devices, their use and maintenance costs are high, hindering the reduction of drilling costs.

[0004] Chinese patent document CN108343380A discloses a directional rotary drilling tool and method for near-horizontal drilling in coal mines. After the pump is shut off, the spline enters the keyway, engaging the mandrel with the curved housing, allowing for tool face adjustment. After the pump is turned on, the spline disengages from the keyway, and the curved housing remains stationary due to friction with the well wall. The drill pipe drives the mandrel and drill bit to rotate, thus achieving rotary orientation. The main drawback is that only directional drilling can be performed during drilling; combined drilling with the curved housing rotation is not possible. Furthermore, the measuring probe is connected to the mandrel system, making it impossible to measure the tool face of the curved housing downhole. In actual drilling, both stationary directional drilling and combined drilling with curved housing rotation are necessary. These two processes must be alternated, and the ratio of the two drilling states must be adjusted according to the actual wellbore trajectory to achieve accurate wellbore trajectory control.

[0005] Chinese patent document ZL201620363357.0 discloses a downhole tubing rotation control switch, which is placed approximately 300m above the screw drill string. The switch can be activated by drilling fluid, allowing the drill string to rotate. The friction of this approximately 300m section of the drill string overcomes the counter-torque of the screw drill string, thus achieving the goal of rotating the drill string during directional drilling. The main drawback is that the friction generated by the drill string's gravity is highly susceptible to changes in motion, potentially leading to instability of the screw drill string and preventing rotation of the approximately 300m section of the drill string. This reduces the rotation ratio of the drill string and negatively impacts the friction reduction and speed-up effects.

[0006] Chinese patent document CN201220454297 discloses a drilling friction and torque reduction tool with an upward and downward rotation mechanism. However, this tool uses an upward and downward control method, which results in severe axial vibration during actual drilling, making it difficult to control. Furthermore, it does not involve the design of the transmission part, and the short section, which is subjected to an axial force of about 100KN, will wear out quickly, thus making it impractical. Summary of the Invention

[0007] To address the technical problems described above, this invention aims to provide a rotary sliding orientation tool. This tool connects to the drill pipe via a mandrel, allowing the top drive to directly drive the drill bit through the drill pipe and mandrel. Furthermore, the curved outer casing controls the rotational attitude through drilling pressure, significantly improving both wellbore trajectory control and mechanical drilling rate. In addition, this rotary sliding orientation tool enables near-bit testing via a measurement system.

[0008] To address this, the present invention provides a rotary sliding directional tool, comprising: a directional housing; a mandrel concentrically arranged within the directional housing, the upper end of the mandrel being connected to a drill rod and the lower end to a drill bit; a measuring system mounted on the directional housing, positioned near the drill bit; and a directional housing rotation control system, including a universal joint; wherein the drill rod drives the drill bit to rotate and drill via the mandrel, and near-drill bit measurements are performed via the measuring system. In a first state, the drilling pressure is adjusted to be greater than a predetermined value by the directional housing rotation control system, causing the mandrel to bend and approach the inner wall of the directional housing, generating friction. This friction enables the directional housing to rotate, thereby performing compound drilling or rotating to adjust the tool face. In a second state, the drilling pressure is adjusted to be less than a predetermined value by the directional housing rotation control system, causing the directional housing to disengage from the mandrel and maintain the tool face unchanged under the action of well wall friction, thereby enabling the directional housing to perform directional drilling while the drill string rotates.

[0009] In one embodiment, the mandrel includes a hollow rod, a water outlet connector, a non-magnetic solid rod, and a water inlet connector connected sequentially from top to bottom. The universal joint connects the non-magnetic solid rod and the water inlet connector, and the universal joint is connected to the non-magnetic solid rod through a universal joint.

[0010] In one embodiment, a friction material layer is provided on the outer surface of the universal joint, and the spindle can approach the inner wall of the directional housing through the universal joint and generate friction through the friction material layer.

[0011] In one embodiment, a lower connector is fixedly connected to the lower end of the water inlet connector. The lower connector is used to connect a drill bit, and a thrust bearing assembly is provided between the lower connector and the directional housing.

[0012] In one embodiment, the water outlet connector is provided with a first flow passage hole, the water inlet connector is provided with a second flow passage hole, the internal flow channel of the hollow rod, the first flow passage hole, the radial annulus between the directional shell and the mandrel, the second flow passage hole, and the internal flow channel of the lower connector are sequentially connected to form a flow passage, through which drilling fluid can flow to the drill bit.

[0013] In one embodiment, the orientation housing includes a measurement system housing and a thrust bearing housing connected to the lower end of the measurement system housing.

[0014] In one embodiment, the measuring system housing is configured to include a curved section of housing located at one end near the drill bit.

[0015] In one embodiment, a pad is provided on the outer surface of the thrust bearing housing, and the curved housing and the pad can work together to orient the directional housing.

[0016] In one embodiment, the axial distance between the pad and the lower connector is in the range of 1-1.5m.

[0017] In one embodiment, an instrument compartment is provided on the housing of the measurement system. The measurement system includes a battery, a directional sensor, a gamma sensor, and a wireless transmission coil installed in the instrument compartment. The instrument compartment is sealed by a sealing cover. The directional sensor and the gamma sensor are capable of measuring formation measurement parameters and transmitting data using the wireless transmission coil.

[0018] In one embodiment, a carbide outer sleeve is fixedly connected to the lower inner wall of the thrust bearing housing, and a carbide inner sleeve is fixedly connected to the outer wall of the lower connector. The carbide inner sleeve is located inside the carbide outer sleeve and a gap is formed between the two, thereby forming a radial bearing.

[0019] In one embodiment, the upper end of the mandrel is connected to the drill rod via an upper connector, and a sealing cylinder is fixedly connected to the upper end of the measuring system housing, forming a rotational seal between the sealing cylinder and the upper connector.

[0020] In one embodiment, a cooling and lubrication system is also included.

[0021] Compared with the prior art, the advantages of this application are:

[0022] The rotary sliding directional tool of the present invention connects to the drill pipe via a mandrel, enabling the top drive to directly drive the drill bit through the drill pipe and mandrel. The curved outer casing controls its rotational attitude via drill pressure, significantly improving the rate of drilling while enhancing wellbore trajectory control. When the wellbore trajectory deviates from the design, the rotary sliding directional tool can achieve directional drilling while the drill string rotates, greatly reducing friction and increasing the rate of drilling. Furthermore, the drill pressure control method is simple and reliable, and can replace currently expensive rotary directional tools, significantly reducing costs. In addition, this rotary sliding directional tool can perform near-bit testing via a measurement system to measure formation parameters, effectively ensuring the accuracy of the measured parameters and greatly facilitating drilling operations. Attached Figure Description

[0023] The present invention will now be described with reference to the accompanying drawings.

[0024] Figure 1 The structure of the rotary sliding orientation tool according to the present invention is shown.

[0025] In this application, all drawings are schematic and are used only to illustrate the principles of the invention, and are not drawn to scale. Detailed Implementation

[0026] The invention will now be described with reference to the accompanying drawings.

[0027] In this application, it should be noted that the end of the rotary sliding directional tool according to the invention that is lowered into the wellbore near the wellhead is defined as the upper end or a similar term, while the end that is farther from the wellhead is defined as the lower end or a similar term. It should also be noted that the directional terms or limiting words such as "upper" and "lower" used in this application are all specific to the referenced appendix. Figure 1 In other words, they are not used to define the absolute position of the components involved, but can vary depending on the specific circumstances.

[0028] Figure 1 The structure of the rotary sliding orientation tool 100 according to the present invention is shown. For example... Figure 1As shown, the rotary sliding orientation tool 100 includes an orientation housing 1, a mandrel 2 concentrically arranged inside the orientation housing 1, a measuring system mounted on the orientation housing 1, and an orientation housing rotation control system. The upper end of the mandrel 2 is connected to a drill rod (not shown), and the lower end is connected to a drill bit. The drill rod is connected to a top drive, which drives the drill rod, allowing the drill rod to directly drive the drill bit through the mandrel 2. The measuring system is positioned near the drill bit, enabling near-drill bit testing. The orientation housing rotation control system includes a universal joint 4, through which the mandrel 2 can bend under drilling pressure. The orientation housing 1 can control its rotational attitude by controlling the drilling pressure, and can be in a stationary or rotating state under the control of the housing rotation control system.

[0029] When compound drilling is required, the drilling pressure is adjusted to a value greater than a predetermined value by the directional housing rotation control system. This causes the mandrel 2 to bend and approach the inner wall of the directional housing 1, generating friction. This friction drives the directional housing 1 to rotate, activating the top drive and causing the drill string, mandrel 2, drill bit, and directional housing 1 to rotate synchronously, thus performing compound drilling. Alternatively, the tool face can be slowly rotated to adjust. At this time, the rotary sliding directional tool 100 is in the first state.

[0030] When directional drilling is required, the drilling pressure is adjusted to a predetermined value by the directional housing rotation control system, causing the directional housing 1 to disengage from the mandrel 2. Under the action of well wall friction, the directional housing 1 maintains a fixed tool face, thereby enabling directional drilling. At this time, the rotary sliding directional tool 100 is in the second state.

[0031] According to the present invention, such as Figure 1 As shown, the mandrel 2 includes a hollow rod 21, a water outlet connector 22, a non-magnetic solid rod 23, and a water inlet connector 24, connected sequentially from top to bottom. The hollow rod 21, water outlet connector 22, non-magnetic solid rod 23, and water inlet connector 24 are all connected by threaded connections. The non-magnetic solid rod 23 is made of non-magnetic material, while the hollow rod 21, water outlet connector 22, and water inlet connector 24 are made of 4330V high-strength alloy steel.

[0032] The upper end of the mandrel 2 is connected to the drill pipe via an upper connector 9. The upper end of the upper connector 9 is a drill pipe thread with the same outer diameter as the drill bit connector, used to connect the upper drill pipe. The lower end of the upper connector 9 is constructed as a trapezoidal thread, used to connect the hollow rod 21 in the mandrel 2. The upper connector 9 is connected to the top drive via the drill pipe. Thus, the drill pipe can be driven by the top drive, allowing the drill pipe to directly drive the drill bit to drill through the mandrel 2.

[0033] The universal joint 4 connects the non-magnetic solid rod 23 and the water inlet connector 24. The universal joint 4 is connected to the lower end of the non-magnetic solid rod 23 through the universal joint 41. The upper end of the universal joint 41 is fixedly connected to the lower end of the non-magnetic solid rod 23, and the lower end of the universal joint 41 is connected to the water inlet connector 24 in a universal manner. The universal joint 41 allows the spindle 2 to be connected at a certain angle, thereby enabling the spindle 2 to adapt to the external curved housing structure (see below).

[0034] According to the present invention, a friction material layer (not shown) is provided on the outer surface of the universal joint 41, and the friction material layer is formed of a material with a high coefficient of friction. The mandrel 2 can approach the inner wall surface of the directional housing 1 through the universal joint 41 and generate friction through the friction material layer. Thus, the mandrel 2 drives the directional housing 1 to rotate through friction and enter the composite drilling.

[0035] like Figure 1 As shown, a lower connector 5 is fixedly connected to the lower end of the water inlet connector 24 of the mandrel 2. The lower connector 5 is used to connect the drill bit. Thus, the drill bit is connected to the lower end of the mandrel 2 via the lower connector 5. In one embodiment, the lower connector 5 is configured to include a cylindrical body, and the lower end of the cylindrical body is configured as a tapered connecting buckle for connecting with the drill bit. A tubular connecting portion is formed at the upper end of the cylindrical body. The tubular connecting portion is inserted into the directional housing 1 and extends upward to connect with the water inlet connector 24 of the mandrel 2. The outer diameter of the tubular connecting portion is smaller than the outer diameter of the cylindrical body, thereby forming an upward-facing step on the outer surface of the outer connector 5.

[0036] According to the present invention, the water outlet connector 22 is constructed into a cylindrical structure, and both ends of the water outlet connector 22 are respectively constructed into trapezoidal buckles for connecting the hollow rod 21 and the non-magnetic solid rod 23. The side wall of the water outlet connector 22 is provided with a first flow-through hole 221 penetrating the side wall, and the first flow-through hole 221 is located near the axial center of the water outlet connector 22. Multiple first flow-through holes 221 are provided and evenly distributed in the circumferential direction, for example, 4-6 holes can be provided. The diameter of the orifice of the first flow-through hole 221 is set to 1 / 4 of the outer diameter of the water outlet connector 22.

[0037] The inlet connector 24 and outlet connector 22 have similar structures. The inlet connector 24 is also constructed as a cylindrical structure, with trapezoidal buckles at both ends for connecting the universal joint 4 and the lower connector 5, respectively. The side wall of the inlet connector 24 has a second flow-through hole 241 penetrating the side wall, located near the axial center of the inlet connector 24. Multiple second flow-through holes 241 are provided, evenly distributed circumferentially, for example, 4-6 holes can be provided. The diameter of the second flow-through hole 241 is set to 1 / 4 of the outer diameter of the inlet connector 24.

[0038] The directional housing 1 is fitted onto the outside of the mandrel 2, forming a radial annulus between the directional housing 1 and the mandrel 2. The internal flow channel of the hollow rod 21, the first flow hole 221 of the water outlet connector 22, the radial annulus between the directional housing 1 and the mandrel 2, the second flow hole 241 of the water inlet connector 24, and the internal flow channel of the lower connector 5 are sequentially connected to form a flow passage. Drilling fluid enters the internal flow channel of the hollow rod 21 from the upper connector 9, then flows through the flow passage, and finally flows through the drill bit.

[0039] like Figure 1 As shown, a thrust bearing assembly 2' is provided between the lower connector 5 and the directional housing 1. The thrust bearing assembly 2 includes 6-10 sets of thrust bearings. The directional housing 1 is fixed to the outer ring of the thrust bearing assembly, and the mandrel 2 is fixed to the inner ring of the thrust bearing assembly, thereby fixing the directional housing 1 to the mandrel 2 and enabling the mandrel 2 to rotate relative to the directional housing 1 during directional drilling, while the rotational resistance is relatively small and easy to control.

[0040] According to the present invention, the directional housing 1 includes a measurement system housing 11 and a thrust bearing housing 12 connected to the lower end of the measurement system housing 11. The mandrel 2 is correspondingly located within the measurement system housing 11, and the thrust bearing assembly 2' is correspondingly located within the thrust bearing housing 12. The outer diameter of the directional housing 1 is 40-50 mm smaller than the wellbore diameter. In one embodiment, the measurement system housing 11 and the thrust bearing housing 12 can be connected by a tapered fastener.

[0041] In one embodiment, a carbide outer sleeve 7 is fixedly connected to the lower inner wall of the thrust bearing housing 12. Preferably, the carbide outer sleeve 7 is fixedly connected to the lower inner wall of the thrust bearing housing 12 via threads. Simultaneously, a carbide inner sleeve 8 is fixedly connected to the outer wall of the tubular connecting portion of the lower connector 5. The carbide inner sleeve 8 is located inside the carbide outer sleeve 7, and a gap is formed between the carbide inner sleeve 8 and the carbide outer sleeve 7. Preferably, the gap is 0.3 mm, thereby forming a radial bearing structure with excellent wear resistance between the carbide inner sleeve 8 and the carbide outer sleeve 7.

[0042] In this embodiment, an inner limiting step with its end face facing upward is provided on the inner wall of the thrust bearing housing 12, and an outer limiting step with its end face facing upward is provided on the outer wall of the tubular connecting portion of the lower connector 5. The upper end face of the outer ring of the thrust bearing assembly in the thrust bearing assembly 2' abuts against the inner limiting step, and the lower end face abuts against the upper end face of the carbide outer sleeve 7. At the same time, the upper end face of the inner ring of the thrust bearing assembly in the thrust bearing assembly 2' abuts against the outer limiting step, and the lower end face abuts against the upper end face of the carbide inner sleeve 8. Thus, axial limiting is formed for the thrust bearing assembly 2'.

[0043] According to the present invention, the measuring system housing 11 is configured to include a curved housing section located at one end near the drill bit. A universal joint 4 and a universal connector 41 correspond to the location of the curved housing. The universal joint 41 allows the mandrel 2 to be connected at a certain angle, thereby enabling the mandrel 2 to adapt to the external curved housing structure. Thus, the mandrel 2 can generate a certain bending angle under drilling pressure, achieving adjustment and control of the rotational attitude of the rotary sliding orientation tool 100 through drilling pressure. The curved housing guides the drill bit's direction, thereby achieving orientation.

[0044] like Figure 1 As shown, an arc-shaped pad 6 is machined on the lower outer circumference of the thrust bearing assembly housing 12. The pad 6 forms a fulcrum, allowing the curved housing and the pad 6 to work together to orient the oriented housing 1. The axial distance between the pad 6 and the end face of the outer step of the lower connector 5 is 1-1.5m. When the pad 6 is at the lower end, it is equivalent to pushing the drill bit upward, thus creating a directional drilling capability; conversely, when it is at the lower end, the drill bit drills downward, thus creating a deflection capability.

[0045] In one embodiment, the outer surface of the pad 6 is arc-shaped and is fitted with several pieces of hard alloy, which significantly improves wear resistance.

[0046] An instrument compartment 30 is provided on the housing 11 of the measurement system. The measurement system includes a battery, a directional sensor, a gamma sensor, and a wireless transmission coil (not shown) installed in the instrument compartment 30. The instrument compartment 30 is sealed by a sealing cover. The directional sensor and the gamma sensor can measure formation measurement parameters and transmit the data using the wireless transmission coil. The directional sensor is used to measure three parameters in real time: well inclination angle, azimuth angle, and tool face angle. The gamma sensor is used to measure the gamma value of the formation. After measurement, both sensors transmit the data using the wireless transmission coil. The battery powers the directional sensor, the gamma sensor, and the coil.

[0047] In one embodiment, the measurement system housing 11 is made of a non-magnetic material. Four slots are machined on the outer peripheral surface of the housing 11 to house the battery, orientation sensor, gamma sensor, and wireless transmitting coil, respectively. Four sealing covers are installed on the four slots. A 5mm wide gap is left in the middle of the cover corresponding to the wireless transmitting coil slot, which is filled with plastic to facilitate the coil's electromagnetic wave emission. The inner diameter of the measurement system housing 11 is 10mm larger than the outer diameter of the non-magnetic solid rod 23 to form a radial annulus between the housing 11 and the mandrel 2, thus creating a flow channel for drilling fluid.

[0048] like Figure 1 As shown, a sealing cylinder 10 is fixedly connected to the upper end of the measuring system housing 11, and a rotational seal is formed between the sealing cylinder 10 and the upper connector 9.

[0049] According to the present invention, the rotary sliding orientation tool 100 further includes a cooling and lubrication system. The cooling and lubrication system is divided into upper and lower parts. After the drilling fluid flows out from the first flow hole 221 of the water outlet connector 22, about 5% of the drilling fluid passes between the thrust bearing assembly and the cemented carbide inner sleeve 8 and the cemented carbide outer sleeve 7, thereby cooling and lubricating the thrust bearing assembly, the cemented carbide inner sleeve 8 and the cemented carbide outer sleeve 7, and then drains into the outer annulus.

[0050] The working process of the rotary sliding orientation tool 100 according to the present invention is briefly described below.

[0051] In actual operation, firstly, based on the requirements of the drilling process, a feasible range of drilling pressure is determined, and the intermediate value is taken as the critical value (i.e., the predetermined value). Then, the lower end of the rotary sliding directional tool 100 is connected to the drill bit via the lower connector 5, and the upper end is connected to the upper drill pipe via the upper connector 9. The upper drill pipe includes a non-magnetic pressure-bearing drill pipe and drill rods. The upper drill pipe is connected to the top drive. The top drive directly drives the drill bit to drill through the drill rods and mandrel 2.

[0052] Once the drilling pressure is adjusted to above the critical value, start the top drive and adjust it to the normal rotation speed. If the wellbore trajectory meets the design requirements and no orientation is needed, continue drilling according to the above parameters.

[0053] After drilling a certain distance, if the wellbore trajectory deviates from the design and directional drilling is required, the tool face, i.e., the bend angle of the curved housing and the circumferential position of the pad, is first determined according to the requirements of the wellbore trajectory. Then, the tool face is adjusted at a low rotational speed. Once the tool face is in place, the drilling pressure is reduced to below the critical value through the directional housing rotation control system, causing the universal joint 41 to disengage from the directional housing 1 and the mandrel 2 to disengage from the directional housing 1. Due to the friction between the pad 6 of the directional housing 1 and the well wall, the directional housing 1 remains stationary. Finally, the top drive speed is restarted to normal, and the top drive drives the drill string, mandrel 2, and drill bit to rotate and drill. Meanwhile, the directional housing 1 maintains its tool face unchanged under the action of the well wall friction, thus achieving the purpose of drill string rotation and directional housing sliding for directional drilling. This significantly reduces friction and increases the mechanical drilling rate. At this time, the rotary sliding directional tool 100 is in the directional drilling state, i.e., in the first state.

[0054] After drilling for a period of time, the wellbore trajectory design target has been achieved. The drilling pressure is then adjusted again to a combined drilling state. Specifically, the drilling pressure is adjusted to a higher value than a predetermined value through the directional housing rotation control system. This causes the mandrel 2 to bend and approach the inner wall of the directional housing 1. The universal joint 41 then contacts the inner wall of the directional housing 1 through the friction material layer, generating friction. This friction drives the directional housing 1 to rotate, thus forming a single unit between the directional housing 1 and the mandrel 2. The top drive is then activated, and the drill string, mandrel 2, drill bit, and directional housing 1 rotate synchronously, thus performing combined drilling. Alternatively, the tool face can be slowly rotated for adjustment. At this point, the rotary sliding directional tool 100 returns to the second state.

[0055] During drilling operations, the rotary sliding directional tool 100 switches between a first state and a second state as needed to ensure that the wellbore trajectory meets the design requirements, thereby completing the drilling operation.

[0056] The rotary sliding directional tool 100 of the present invention is connected to the drill pipe via a mandrel 2, enabling the top drive to directly drive the drill bit through the drill pipe and mandrel 2. The curved outer casing controls its rotational attitude via drilling pressure, significantly improving the rate of drilling while enhancing wellbore trajectory control. When the wellbore trajectory deviates from the design, the rotary sliding directional tool 100 can achieve directional drilling while the drill string rotates, greatly reducing friction and increasing the rate of drilling. Furthermore, the drilling pressure control method is simple and reliable, and can replace currently expensive rotary directional tools, significantly reducing costs. In addition, the rotary sliding directional tool 100 can also perform near-bit testing via a measurement system to measure formation parameters, effectively ensuring the accuracy of the measured parameters and greatly facilitating drilling operations.

[0057] In the description of this invention, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0058] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0059] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0060] Finally, it should be noted that the above description is merely a preferred embodiment of the present invention and does not constitute any limitation on the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A rotary sliding directional drilling tool, comprising: a directional housing (1); a core shaft (2) concentrically arranged in the directional housing, the core shaft having an upper end connected to a drill pipe and a lower end connected to a drill bit, the core shaft being capable of producing a bending angle under the action of a weight on bit; a measuring system mounted on the directional housing and arranged near the drill bit; and a directional housing rotation control system comprising a universal shaft (4); wherein the core shaft comprises, from top to bottom, a hollow rod (21), a water outlet joint (22), a non-magnetic solid rod (23), and a water inlet joint (24), the universal shaft being connected between the non-magnetic solid rod and the water inlet joint, the universal shaft being connected to the non-magnetic solid rod through a universal joint (41), wherein the drill pipe drives the drill bit to rotate and drill by the core shaft, and near-bit measurement is performed by the measuring system, in a first state, the weight on bit is adjusted to be greater than a predetermined value by the directional housing rotation control system, the core shaft is caused to bend and approach the inner wall of the directional housing to generate a friction force, and the directional housing is further caused to rotate by the friction force, so as to perform composite drilling or adjust the tool face, in a second state, the weight on bit is adjusted to be less than the predetermined value by the directional housing rotation control system, the directional housing is separated from the core shaft, and the tool face is kept unchanged under the action of the friction of the well wall, so that the directional housing is capable of directional drilling when the drill string rotates.

2. The rotational sliding directional tool of claim 1, wherein, A layer of friction material is arranged on the outer surface of the universal joint, and the core shaft is capable of approaching the inner wall of the directional housing through the universal joint and generating a friction force through the layer of friction material.

3. A rotational sliding directional tool according to claim 1 or 2, characterized in that, A lower joint (5) is fixedly connected to the lower end of the water inlet joint, the lower joint being used for connecting the drill bit, and a thrust bearing assembly (2') is arranged between the lower joint and the directional housing.

4. The rotational sliding directional tool of claim 3, wherein, The water outlet joint is provided with a first flow hole (221), and the water inlet joint is provided with a second flow hole (241), an internal flow passage of the hollow rod, the first flow hole, a radial annulus between the directional housing and the core shaft, the second flow hole, and an internal flow passage of the lower joint are sequentially communicated to form a flow passage, and drilling fluid is capable of flowing to the drill bit through the flow passage.

5. The rotational sliding directional tool of claim 3, wherein, The directional housing comprises a measuring system housing (11) and a thrust bearing housing (12) connected to the lower end of the measuring system housing.

6. The rotational sliding directional tool of claim 5, wherein, The measuring system housing is configured to comprise a section of a bent housing, the bent housing being located at one end close to the drill bit.

7. The rotational sliding directional tool of claim 6, wherein, A pad (6) is arranged on the outer surface of the thrust bearing housing, and the bent housing and the pad are capable of jointly acting to orient the directional housing.

8. The rotational sliding directional tool of claim 7, wherein, The axial spacing between the pad and the lower joint is within a range of 1-1.5 m.

9. The rotational sliding directional tool of claim 5, wherein, An instrument bin (30) is arranged on the measuring system housing, the measuring system comprising a battery, a directional sensor, a gamma sensor, and a wireless transmitting coil mounted in the instrument bin, the instrument bin being sealed by a sealing cover plate, the directional sensor and the gamma sensor are capable of measuring formation parameters, and the wireless transmitting coil is used to transmit data.

10. The rotational sliding directional tool of claim 5, wherein, The lower end inner wall of the thrust bearing shell is fixedly connected with a hard alloy outer sleeve (7), the outer wall of the lower joint is fixedly connected with a hard alloy inner sleeve (8), the hard alloy inner sleeve is located at the inner side of the hard alloy outer sleeve and a gap is formed between the two, thereby forming a radial bearing.

11. The rotational sliding directional tool of claim 5, wherein, The upper end of the core shaft is connected with a drill pipe through an upper joint (9), a sealing cylinder (10) is fixedly connected at the upper end of the measuring system shell, and the sealing cylinder and the upper joint form a rotating seal.

12. The rotational sliding directional tool of claims 1 or 2, wherein, A cooling and lubricating system is further included.

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