Resistance and torque reduction tool with self-stabilizing disc valve type hydraulic pulse nipple

Abstract

The application discloses a drag-reducing and torque-reducing tool with a self-stabilizing disc valve type hydraulic pulse nipple, which comprises a vibration nipple, a first shell structure connected with a core shaft, a first central hole arranged through the core shaft, and the core shaft connected with an upper drill string; a pulse nipple, which comprises a second shell structure, a stabilizing shaft arranged in the second shell structure, and the second shell structure capable of rotating in a circumferential direction relative to the stabilizing shaft, eccentric weight sleeves and self-stabilizing disc valves arranged on the stabilizing shaft in an interval mode, and a flow ring gap arranged between the eccentric weight sleeves and the second shell structure; a rotating valve fixedly arranged in the second shell structure; a first flow passage arranged on the self-stabilizing disc valve, and a second flow passage arranged on the rotating valve, wherein the second flow passage intermittently communicates with the first flow passage to generate a pressure pulse, and the core shaft generates axial vibration under the action of the pressure pulse. The self-stabilizing disc valve structure generates the pressure pulse by utilizing the self-stabilization of the eccentric weight, and the vibration nipple is matched to form impact vibration on the drill string, so that the drag and torque in the drilling process are reduced.

Description

Technical Field

[0001] This invention relates to the field of drilling and completion technology, and in particular to a drag-reducing and torque-reducing tool equipped with a self-stabilizing disc valve type hydraulic pulse sub. Background Technology

[0002] Due to the needs of unconventional development, offshore development, onshore oil and gas production, and environmental protection, the number of complex well structures, such as extended reach wells, highly deviated wells, and long horizontal wells, is constantly increasing. Especially in the development of unconventional shale oil and gas, the inherent defects of low porosity, low permeability, and low abundance make development extremely difficult, and long horizontal well technology is a key technology for its economical development. However, with the continuous lengthening of horizontal well sections and the increasing demand for complex well structures, the pressure exerted by the wellbore on the drill string leads to difficulties in drill pressure transmission, resulting in prominent issues of high friction and high torque, directly affecting the extension capacity of the horizontal section. Simultaneously, high friction and torque lead to frequent complex accidents such as stuck drill string breakage and entrapment of the swivel guide, increasing non-productive work time and drilling costs, seriously affecting the efficiency of oil and gas exploration and development. Therefore, research on friction reduction and drag reduction technologies and supporting tools for long horizontal well sections is of great significance.

[0003] Hydraulic oscillators, based on the theory of vibration-induced friction reduction, convert some of the drilling fluid energy into hydraulic energy, inducing vibration of the drill string near the tool. This reduces friction between the drill string and the wellbore, thus achieving friction reduction and drag reduction. Commonly used hydraulic oscillators include screw-type and turbine-type structures. These utilize a screw or turbine to drive a pulse disc valve, generating pressure pulses. These pressure pulses act on the piston surface of the oscillating section, compressing or releasing the internal disc spring assembly to achieve reciprocating vibration. Screw-type hydraulic oscillators use a screw as the power source for the disc valve, but the use of stator rubber inside the screw results in weak high-temperature resistance. Turbine-type hydraulic oscillators, due to their high turbine speed, produce excessively high pulse frequencies, leading to similarly high compression and recovery frequencies of the disc springs in the oscillating section. This results in poor oscillation performance, limited vibration transmission distance, and ineffective vibration drag reduction. Meanwhile, both screw-type and turbine-type hydraulic oscillators use screws or turbines as power to drive the disc valve rotation, resulting in significant pressure loss. In the drilling process of long horizontal wells, the high pump pressure caused by pressure loss limits the use of the tools.

[0004] Therefore, in response to the problems of insufficient temperature resistance, excessively high oscillation frequency, and excessive pressure loss of the aforementioned hydraulic oscillation tools, the inventor, based on years of experience and practice in related industries, proposes a drag-reducing and torque-reducing tool with a self-stabilizing disc valve type hydraulic pulse sub, to overcome the defects of the prior art, improve the friction-reducing and drag-reducing effect of long horizontal wells and complex structure wells, and help to speed up and improve drilling efficiency. Summary of the Invention

[0005] The purpose of this invention is to provide a drag-reducing and torque-reducing tool equipped with a self-stabilizing disc valve type hydraulic pulse sub. Utilizing the self-stabilization of the eccentric counterweight, the self-stabilizing disc valve structure generates pressure pulses, which, in conjunction with the vibrating sub, create impact vibrations on the drill string, thereby reducing frictional torque during drilling. This tool requires no power drive mechanism, significantly reducing tool pressure loss.

[0006] The objective of this invention is achieved by providing a drag-reducing and torque-reducing tool equipped with a self-stabilizing disc valve type hydraulic pulse sub, comprising:

[0007] The vibration sub includes a first outer shell structure, in which a spindle capable of axial movement is fixedly connected circumferentially, a first central hole is provided through the spindle, and the top end of the spindle is connected to an upper drill string;

[0008] The pulse sub includes a second outer shell structure connected to the first outer shell structure, with the bottom end of the second outer shell structure connected to the lower drill string; an axially fixed stabilizing shaft is provided inside the second outer shell structure, and the second outer shell structure can rotate circumferentially relative to the stabilizing shaft; an eccentric counterweight sleeve and a self-stabilizing disc valve are spaced apart on the stabilizing shaft, and a flow annular gap that can communicate with the first central hole is provided between the eccentric counterweight sleeve and the second outer shell structure; a rotary valve is fixedly provided below the self-stabilizing disc valve inside the second outer shell structure; a first flow channel that can communicate with the flow annular gap is axially provided on the self-stabilizing disc valve, and a second flow channel that can communicate with the rotary valve is axially provided. The second flow channel intermittently connects to the first flow channel to generate pressure pulses in the drilling fluid, and the mandrel generates axial vibration under the action of the pressure pulses.

[0009] In a preferred embodiment of the present invention, the eccentric counterweight sleeve includes a cylindrical body, a weight-reducing groove axially extending through one side of the cylindrical body, and an arcuate semi-groove at the center of the cylindrical body that can be fitted onto the outside of the stabilizing shaft; a first inner groove is provided at the top end of the cylindrical body, and a first step is provided on the outer wall of the stabilizing shaft, the first inner groove being fitted onto the first step; the bottom end of the stabilizing shaft is axially fixed by a fixing nut fitted onto the stabilizing shaft.

[0010] In a preferred embodiment of the present invention, the outer wall of the self-stabilizing disc valve is provided with an outer conical surface facing downward.

[0011] In a preferred embodiment of the present invention, a support base is fixedly disposed inside the second outer shell structure, and a second central hole is axially provided at the center of the support base, and the top end of the stabilizing shaft is hinged to the second central hole; a third through-flow channel is also provided on the support base, and the third through-flow channel can connect the first central hole and the through-flow annular gap.

[0012] In a preferred embodiment of the present invention, the top end of the stabilizing shaft is hinged to the second central hole via an upper bearing; the inner wall of the second central hole is provided with a second step portion, the outer wall of the stabilizing shaft is provided with a third step portion, the top end of the second central hole is fixedly connected to a bearing cap, the top end of the stabilizing shaft is connected to an upper bearing fixing nut, and the bearing cap, the upper bearing fixing nut, the second step portion, and the third step portion axially fix the upper bearing.

[0013] In a preferred embodiment of the present invention, a third central hole is axially provided at the center of the rotary valve, and the bottom end of the stabilizing shaft is hinged to the third central hole via a lower bearing; a fourth step is provided on the inner wall of the third central hole, and a fifth step is provided on the outer wall of the stabilizing shaft; a bearing end cap is fixedly connected to the bottom end of the third central hole, and a lower bearing fixing nut is connected to the bottom end of the stabilizing shaft; the bearing end cap, the lower bearing fixing nut, and the third flow channel are arranged in a fan shape in a preferred embodiment of the present invention.

[0014] In a preferred embodiment of the present invention, the first housing structure includes a splined housing and a disc spring housing connected in sequence. A piston is disposed inside the disc spring housing at the bottom end of the mandrel. The piston can drive the mandrel to generate axial vibration under the action of a pressure pulse from below. A disc spring is disposed between the mandrel and the disc spring housing. The mandrel and the splined housing are connected by a spline.

[0015] In a preferred embodiment of the present invention, the inner wall of the spline shell is provided with an annular groove, the bottom end face of the annular groove forms a sixth step, the outer wall of the mandrel is provided with a seventh step, and the seventh step can abut against the sixth step to limit the downward movement of the mandrel.

[0016] The bottom end face of the spline housing is located inside the disc spring housing, forming an eighth step. A retaining ring is provided on the spindle inside the disc spring housing. The retaining ring can axially abut against the eighth step to limit the upward movement of the spindle.

[0017] In a preferred embodiment of the present invention, the bottom end of the disc spring housing is connected to the second housing structure through an intermediate connector, and a fourth center hole is provided at the center of the intermediate connector, which can connect the first center hole and the third flow channel.

[0018] As described above, the drag reduction and torque reduction tool of the present invention, equipped with a self-stabilizing disc valve type hydraulic pulse sub, has the following beneficial effects:

[0019] This invention utilizes the self-stability of eccentric counterweights. The stabilizing shaft and self-stabilizing disc valve achieve a stable state during drill string rotation using the eccentric counterweight sleeve. This, in conjunction with the rotation of the drill string, drives the rotary valve to rotate. The second flow channel and the first flow channel are constantly switching between connected opening and staggered closing, generating pressure pulses. These pressure pulses act on the vibrating sub, causing the mandrel to vibrate axially. The axial vibration then propagates to the drill string system connected to the upper and lower ends of the tool, thereby reducing the friction coefficient between the drill string and the well wall, achieving torque reduction and drag reduction, and solving the high friction torque problem that exists in the drilling of long horizontal wells and complex structure wells in the development of unconventional shale oil and gas.

[0020] The invention is simple in principle and structure, highly reliable, and has no power short sections such as screws and turbines. Compared with conventional hydraulic oscillators, it can significantly reduce pressure loss. Moreover, it is an all-metal structure with stronger temperature resistance and has a wide range of application prospects. Attached Figure Description

[0021] The accompanying drawings are intended only to illustrate and explain the present invention and do not limit the scope of the invention.

[0022] in:

[0023] Figure 1 : A cross-sectional view of the drag reduction and torque reduction tool of the present invention, which is equipped with a self-stabilizing disc valve type hydraulic pulse sub. Figure 1 .

[0024] Figure 2 : A cross-sectional view of the drag reduction and torque reduction tool of the present invention, which is equipped with a self-stabilizing disc valve type hydraulic pulse sub. Figure 2 .

[0025] Figure 3 :for Figure 1 Sectional view of AA.

[0026] Figure 4 :for Figure 1 BB section view.

[0027] Figure 5 :for Figure 2 CC section view.

[0028] Figure 6 :for Figure 2 DD section view.

[0029] Figure 7 :for Figure 2 EE section view.

[0030] In the picture:

[0031] 1. Vibration subsection;

[0032] 11. Mandrel; 110. First center hole; 111. Seventh step; 12. Spline housing; 121. Annular groove; 13. Disc spring housing; 14. Piston; 15. Disc spring; 16. Retaining ring;

[0033] 2. Pulse short section;

[0034] 21. Second outer shell structure; 210. Flow annular gap;

[0035] 22. Stabilizing shaft; 221. First step section; 222. Upper bearing; 223. Third step section; 224. Bearing cap; 225. Upper bearing retaining nut; 226. Lower bearing; 227. Fifth step section; 228. Bearing end cap; 229. Lower bearing retaining nut;

[0036] 23. Eccentric counterweight sleeve; 230. Cylindrical body; 231. Weight reduction groove; 232. Circular arc semi-groove; 233. First inner groove;

[0037] 24. Self-stabilizing disc valve; 240. First flow passage; 241. Outer conical surface;

[0038] 25. Rotary valve; 250. Second flow passage; 251. Third center hole; 252. Fourth step;

[0039] 26. Secure the nuts;

[0040] 27. Support base; 270. Third flow channel; 271. Second center hole; 272. Second step;

[0041] 3. Intermediate joint; 30. Fourth center hole. Detailed Implementation

[0042] To provide a clearer understanding of the technical features, objectives, and effects of the present invention, specific embodiments of the present invention will now be described with reference to the accompanying drawings.

[0043] The specific embodiments of the present invention described herein are for illustrative purposes only and should not be construed as limiting the invention in any way. Under the teachings of this invention, those skilled in the art can conceive of any possible modifications based on the invention, all of which should be considered within the scope of the invention. It should be noted that when an element is referred to as being "set on" another element, it can be directly on the other element or there may be an intervening element. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or there may be an intervening element. The terms "mounted," "connected," and "linked" should be interpreted broadly; for example, they can refer to mechanical or electrical connections, or internal communication between two elements, and can be direct or indirect connections through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms according to the specific circumstances. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible embodiments.

[0044] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0045] like Figures 1 to 7 As shown, the present invention provides a drag reduction and torque reduction tool equipped with a self-stabilizing disc valve type hydraulic pulse sub, the upper and lower ends of which are connected to the drill string system (existing technology);

[0046] The present invention includes a vibration section 1 and a pulse section 2 connected in sequence. The pulse section 2 generates a pressure pulse, which propagates upward to the vibration section 1. The vibration section 1 generates axial vibration under the action of the pressure pulse.

[0047] The vibration sub section 1 includes a first outer shell structure, in which a spindle 11 capable of axial movement is fixedly connected circumferentially, and a through first central hole 110 is provided inside the spindle 11; the top end of the spindle 11 is fixedly connected to an upper drill string (prior art).

[0048] The pulse sub 2 includes a hollow second outer shell structure 21. The top end of the second outer shell structure 21 can be fixedly connected to the first outer shell structure (either directly or through a connector). The bottom end of the second outer shell structure 21 is connected to the lower drill string (existing technology). The upper drill string drives the mandrel 11, the first outer shell structure, the second outer shell structure 21 and the lower drill string to rotate.

[0049] The second outer shell structure 21 is provided with an axially fixed stabilizing shaft 22. The second outer shell structure 21 can rotate circumferentially relative to the stabilizing shaft 22. An eccentric counterweight sleeve 23 and a self-stabilizing disc valve 24 are provided at intervals on the stabilizing shaft 22. The stabilizing shaft 22 and the self-stabilizing disc valve 24 achieve a stable state during the rotation of the drill string by means of the eccentric counterweight sleeve 23.

[0050] An annular gap 210 that can communicate with the first central hole 110 is provided between the eccentric counterweight sleeve 23 and the second outer shell structure 21; a rotary valve 25 is fixedly installed inside the second outer shell structure 21 below the self-stabilizing disc valve 24, and the bottom end of the stabilizing shaft 22 is hinged to the rotary valve 25; the rotary valve 25 is fixedly connected to the second outer shell structure 21, so it can rotate synchronously with the drill string and generate relative circumferential motion relative to the stabilizing shaft 22, the eccentric counterweight sleeve 23 and the self-stabilizing disc valve 24;

[0051] like Figure 7 As shown, a first flow channel 240 that can communicate with the flow annular gap 210 is provided through the self-stabilizing disc valve 24, and a second flow channel 250 is provided through the rotary valve 25. The second flow channel 250 is intermittently connected to the first flow channel 240 (because the rotary valve 25 rotates circumferentially relative to the self-stabilizing disc valve 24, the second flow channel 250 and the first flow channel 240 are constantly switching between connected opening and staggered closing) so that the drilling fluid generates pressure pulses. The mandrel 11 generates axial vibration under the action of the pressure pulses, and then the axial vibration is propagated to the drill string system connected to the upper and lower ends (top and bottom ends) of the tool.

[0052] This invention utilizes the self-stability of an eccentric counterweight. The stabilizing shaft 22 and the self-stabilizing disc valve 24 achieve a stable state during drill string rotation using the eccentric counterweight sleeve 23. This, in conjunction with the rotation of the drill string, drives the rotary valve 25 to rotate. The second flow channel 250 and the first flow channel 240 continuously switch between open and staggered closure, generating pressure pulses. These pressure pulses act on the vibrating sub 1, causing the mandrel 11 to vibrate axially. This axial vibration then propagates to the drill string system connected to the upper and lower ends of the tool, thereby reducing the friction coefficient between the drill string and the wellbore, achieving torque reduction and drag mitigation. This solves the high friction torque problem existing in drilling long horizontal wells and complex structure wells during unconventional shale oil and gas development. The invention is simple in principle and structure, highly reliable, and the tool has no screw, turbine, or other power subs. Compared with conventional hydraulic oscillators, it can significantly reduce pressure loss. Furthermore, its all-metal structure provides stronger temperature resistance, making it a promising tool for widespread application.

[0053] Furthermore, such as Figure 1 , Figure 2 , Figure 6As shown, the eccentric counterweight sleeve 23 includes a cylindrical body 230, with a weight-reducing groove 231 extending axially through one side inside the cylindrical body 230, and an arc-shaped semi-groove 232 at the center of the cylindrical body 230 that can be fitted onto the outside of the stabilizing shaft; a first inner groove 233 is provided inward at the top of the cylindrical body 230, and a first step portion 221 is provided on the outer wall of the stabilizing shaft 22, with the first inner groove 233 abutting against the first step portion 221; the bottom end of the stabilizing shaft 22 is axially abutted and fixed by a fixing nut 26 (threaded to the stabilizing shaft 22) fitted onto the stabilizing shaft.

[0054] Furthermore, such as Figure 1 , Figure 2 As shown, the top of the outer wall of the self-stabilizing disc valve 24 has an outer conical surface 241 facing downwards, which is beneficial to the flow of drilling fluid.

[0055] Furthermore, such as Figure 1 , Figure 2 As shown, a support seat 27 is fixedly installed inside the second outer shell structure 21. The upper part of the inner wall of the second outer shell structure 21 is threaded, and the support seat 27 can be screwed to the upper part of the second outer shell structure 21 for fixation. A second central hole 271 is axially provided at the center of the support seat 27, and the top end of the stabilizing shaft 22 is hinged in the second central hole 271. A third flow channel 270 (multiple channels are provided at intervals along the circumference) is also provided on the support seat 27. The third flow channel 270 can connect the first central hole 110 and the flow annular gap 210.

[0056] Furthermore, such as Figure 1 , Figure 2 As shown, the top end of the stabilizing shaft 22 is hinged to the second central hole 271 via the upper bearing 222; the inner wall of the second central hole 271 is provided with a second step portion 272 (step surface, located at the axial center position), and the outer wall of the stabilizing shaft 22 is provided with a third step portion 223. The top end of the second central hole 271 is fixedly connected (threaded connection) to a bearing cap 224, which presses the upper bearing 222; the top end of the stabilizing shaft 22 is connected to an upper bearing fixing nut 225, and the bearing cap 224, the upper bearing fixing nut 225, the second step portion 272, and the third step portion 223 axially fix the upper bearing 222.

[0057] Furthermore, such as Figure 1 , Figure 2As shown, a third central hole 251 is axially provided at the center of the rotary valve 25. The bottom end of the stabilizing shaft 22 is hinged to the third central hole 251 through a lower bearing 226. A fourth step 252 is provided on the inner wall of the third central hole 251, and a fifth step 227 is provided on the outer wall of the stabilizing shaft 22. A bearing end cap 228 is fixedly connected to the bottom end of the third central hole 251, and a lower bearing fixing nut 229 is connected to the bottom end of the stabilizing shaft 22. The bearing end cap 228, the lower bearing fixing nut 229, the fourth step 252, and the fifth step 227 axially fix the lower bearing 226.

[0058] The support 27 and the rotary valve 25 are fixed inside the second housing structure 21 to achieve axial fixation of the stabilizing shaft 22.

[0059] Furthermore, such as Figure 3 , Figure 4 As shown, the cross-sections of the first flow channel 240, the second flow channel 250, and the third flow channel 270 are arranged in a fan shape. The pulse sub-section 2 generates pressure pulses by opening and closing the fan-shaped first flow channel 240 and second flow channel 250.

[0060] Furthermore, such as Figure 1 , Figure 2 , Figure 5 As shown, the first housing structure includes a spline housing 12 and a disc spring housing 13 connected in sequence. A piston 14 is provided inside the disc spring housing 13 at the bottom end of the spindle 11. The piston 14 can push the spindle 11 to generate axial vibration under the action of the pressure pulse below. A disc spring 15 is provided between the spindle 11 and the disc spring housing 13. The spindle 11 and the spline housing 12 are connected by a spline.

[0061] The spindle 11 and the splined housing 12 are connected by a spline, which can ensure that the spindle 11 can move axially relative to the splined housing 12 while transmitting torque.

[0062] A piston 14 is installed at the bottom of the mandrel 11. A pressure pulse acts on the oscillating short piston 14. Under the action of the pressure pulse, the piston 14 drives the mandrel 11 to generate axial vibration. The axial vibration then propagates to the drill string system connected to the upper and lower ends of the tool, thereby reducing the friction coefficient between the drill string and the well wall and achieving torque reduction and drag reduction.

[0063] Furthermore, such as Figure 1 , Figure 2 As shown, the inner wall of the spline housing 12 is provided with an annular groove 121, the bottom end face of the annular groove forms a sixth step, and the outer wall of the spindle 11 is provided with a seventh step 111. The seventh step 111 can abut against the sixth step to limit the downward movement of the spindle 11.

[0064] The bottom end face of the spline housing 12 is located inside the disc spring housing 13, forming the eighth step. A retaining ring 16 is provided on the spindle 11 at a position inside the disc spring housing 13. The retaining ring 16 can axially abut against the eighth step to limit the upward movement of the spindle 11.

[0065] The spindle 11 has a stepped surface machined in the middle, which cooperates with the stepped surface inside the disc spring housing 13 to realize the compression and release of the disc spring 15.

[0066] Furthermore, such as Figure 1 , Figure 2 As shown, the bottom end of the disc spring housing 13 is connected to the second housing structure 21 through the intermediate connector 3. A fourth center hole 30 is provided at the center of the intermediate connector 3. The fourth center hole 30 can connect the first center hole 110 and the third flow channel 270.

[0067] The intermediate joint 3 is connected by threads to the disc spring housing 13 of the upper vibration short section and the second housing structure 21 (pulse short-circuit housing) of the lower section.

[0068] The specific process by which the drag-reducing and torque-reducing tool of the present invention, equipped with a self-stabilizing disc valve type hydraulic pulse sub, achieves drag-reducing and torque-reducing in drilling is as follows:

[0069] First, the connection position of the tool in the drill string system is determined through friction torque analysis and vibration drag reduction calculation. Then, the tool is connected to the drill string and lowered into the well.

[0070] Then, the drilling fluid is circulated and the rotary table or top drive (existing technology) is turned on to drive the drill string to rotate.

[0071] During the rotation of the drill string, since the rotary valve 25 is fixedly connected to the second housing structure 21, the rotary valve 25 will rotate with the drill string. At this time, the fan-shaped flow channels (first flow channel 240 and second flow channel 250) of the self-stabilizing disc valve 24 and the rotary valve 25 will be constantly switching between opening and closing, thereby forming a pressure pulse. The pressure pulse propagates upward to the vibrating sub, and the vibrating sub generates axial vibration under the action of the pressure pulse (the pressure pulse acts on the piston 14 of the vibrating sub, and the piston 14 drives the mandrel 11 to generate axial vibration under the action of the pressure pulse), which in turn drives the tool connecting drill string to generate axial vibration.

[0072] According to the vibration friction reduction theory, when the drill string vibrates, the friction coefficient between the drill string and the well wall decreases. Therefore, by adopting this invention, the driving torque and friction of the drill string system during drilling will be significantly reduced.

[0073] As described above, the drag reduction and torque reduction tool of the present invention, equipped with a self-stabilizing disc valve type hydraulic pulse sub, has the following beneficial effects:

[0074] This invention utilizes the self-stability of eccentric counterweights. The stabilizing shaft and self-stabilizing disc valve achieve a stable state during drill string rotation using the eccentric counterweight sleeve. This, in conjunction with the rotation of the drill string, drives the rotary valve to rotate. The second flow channel and the first flow channel are constantly switching between connected opening and staggered closing, generating pressure pulses. These pressure pulses act on the vibrating sub, causing the mandrel to vibrate axially. The axial vibration then propagates to the drill string system connected to the upper and lower ends of the tool, thereby reducing the friction coefficient between the drill string and the well wall, achieving torque reduction and drag reduction, and solving the high friction torque problem that exists in the drilling of long horizontal wells and complex structure wells in the development of unconventional shale oil and gas.

[0075] The invention is simple in principle and structure, highly reliable, and has no power short sections such as screws and turbines. Compared with conventional hydraulic oscillators, it can significantly reduce pressure loss. Moreover, it is an all-metal structure with stronger temperature resistance and has a wide range of application prospects.

[0076] The above description is merely an illustrative embodiment of the present invention and is not intended to limit the scope of the invention. Any equivalent changes and modifications made by those skilled in the art without departing from the concept and principles of the present invention should fall within the scope of protection of the present invention.

Claims

1. A drag-reducing and torque-reducing tool equipped with a self-stabilizing disc valve type hydraulic pulse sub, characterized in that, include, The vibration sub includes a first outer shell structure, in which a spindle capable of axial movement is fixedly connected circumferentially, a first central hole is provided through the spindle, and the top end of the spindle is connected to an upper drill string; The pulse sub includes a second outer shell structure connected to the first outer shell structure, with the bottom end of the second outer shell structure connected to the lower drill string; an axially fixed stabilizing shaft is provided inside the second outer shell structure, and the second outer shell structure can rotate circumferentially relative to the stabilizing shaft; an eccentric counterweight sleeve and a self-stabilizing disc valve are spaced apart on the stabilizing shaft, and a flow annular gap that can communicate with the first central hole is provided between the eccentric counterweight sleeve and the second outer shell structure; a rotary valve is fixedly provided inside the second outer shell structure below the self-stabilizing disc valve; a first flow channel that can communicate with the flow annular gap is axially provided on the self-stabilizing disc valve, and a second flow channel that can axially communicate with the rotary valve; the second flow channel intermittently communicates with the first flow channel to generate pressure pulses in the drilling fluid, and the mandrel generates axial vibration under the action of the pressure pulses; The eccentric counterweight sleeve includes a cylindrical body with an axially penetrating weight-reducing groove on one side. A semi-circular arc groove, capable of fitting onto the outside of the stabilizing shaft, is located at the center of the cylindrical body. A first inner groove is provided at the top of the cylindrical body, and a first step is provided on the outer wall of the stabilizing shaft. The first inner groove abuts against the first step. The bottom end of the stabilizing shaft is axially fixed by a fixing nut fitted onto the stabilizing shaft. A third central hole is axially provided at the center of the rotary valve. The bottom end of the stabilizing shaft is hinged to the third central hole through a lower bearing. A fourth step is provided on the inner wall of the third central hole, and a fifth step is provided on the outer wall of the stabilizing shaft. A bearing end cap is fixedly connected to the bottom end of the third central hole, and a lower bearing fixing nut is connected to the bottom end of the stabilizing shaft. The bearing end cap, the lower bearing fixing nut, the fourth step, and the fifth step axially fix the lower bearing.

2. The drag-reducing and torque-reducing tool with a self-stabilizing disc valve type hydraulic pulse sub as described in claim 1, characterized in that, The outer wall of the self-stabilizing disc valve has a downward-facing outer cone surface at its top.

3. The drag-reducing and torque-reducing tool with a self-stabilizing disc valve type hydraulic pulse sub as described in claim 1, characterized in that, A support base is fixedly installed inside the second outer shell structure. A second central hole is axially provided at the center of the support base, and the top end of the stabilizing shaft is hinged to the second central hole. A third flow channel is also provided on the support base, which can connect the first central hole and the flow annular gap.

4. The drag-reducing and torque-reducing tool with a self-stabilizing disc valve type hydraulic pulse sub as described in claim 3, characterized in that, The top end of the stabilizing shaft is hinged to the second central hole via an upper bearing; the inner wall of the second central hole is provided with a second step, and the outer wall of the stabilizing shaft is provided with a third step; a bearing cap is fixedly connected to the top end of the second central hole, and an upper bearing fixing nut is connected to the top end of the stabilizing shaft; the bearing cap, the upper bearing fixing nut, the second step, and the third step axially fix the upper bearing.

5. The drag-reducing and torque-reducing tool with a self-stabilizing disc valve type hydraulic pulse sub as described in claim 3, characterized in that, The cross-sections of the first flow channel, the second flow channel, and the third flow channel are arranged in a fan shape.

6. The drag-reducing and torque-reducing tool with a self-stabilizing disc valve type hydraulic pulse sub as described in claim 3, characterized in that, The first housing structure includes a splined housing and a disc spring housing connected in sequence. A piston is provided inside the disc spring housing at the bottom end of the mandrel. The piston can push the mandrel to generate axial vibration under the action of the pressure pulse below. A disc spring is provided between the mandrel and the disc spring housing. The mandrel and the splined housing are connected by a spline.

7. The drag-reducing and torque-reducing tool with a self-stabilizing disc valve type hydraulic pulse sub as described in claim 6, characterized in that, The inner wall of the spline housing is provided with an annular groove, the bottom end face of the annular groove forms a sixth step, the outer wall of the mandrel is provided with a seventh step, and the seventh step can abut against the sixth step to limit the downward movement of the mandrel; The bottom end face of the spline housing is located inside the disc spring housing, forming an eighth step. A retaining ring is provided on the spindle inside the disc spring housing. The retaining ring can axially abut against the eighth step to limit the upward movement of the spindle.

8. The drag reduction and torque reduction tool with a self-stabilizing disc valve type hydraulic pulse sub as described in claim 6, characterized in that, The bottom end of the disc spring housing is connected to the second housing structure via an intermediate connector. A fourth center hole is provided at the center of the intermediate connector, and the fourth center hole can connect the first center hole and the third flow channel.

Images