State-adaptive turbine pulse generator

Abstract

The present invention provides a state-adaptive turbine pulse generator, comprising: a pulse generating device, which includes a turbine housing, a turbine shaft, a turbine mechanism sleeved on the turbine shaft, and a valve disc mechanism arranged at the lower end of the turbine shaft, wherein the turbine mechanism drives the turbine shaft to rotate under the action of drilling fluid, and causes the turbine shaft to drive the valve disc mechanism so that the flow area of ​​the valve disc mechanism changes periodically to generate pressure pulses; an automatic control mechanism for controlling the working state of the pulse generating device, which includes an outer cylinder; a first slider and a second slider axially spaced from each other and arranged in the outer cylinder, the first slider and the second slider being able to move axially along the outer cylinder; and a slider driving mechanism, wherein a stop block is provided on the inner wall of the upper end of the turbine shaft, and a brake block is provided at the lower end of the second slider, and the slider driving mechanism is configured to enable the first slider and the second slider to be axially relatively close to or away from each other, so that the brake block is engaged with or disengaged from the stop block, thereby controlling the working state of the control pulse generating device.

Description

Technical Field

[0001] The invention belongs to the technical field of drilling, and in particular relates to a state-adaptive turbine pulse generator. Background Art

[0002] In the drilling of extended-reach and horizontal wells, due to the large well inclination angle, most of the drill string's own weight presses against the wellbore wall in the highly inclination section. Therefore, the friction between the string and the wellbore is large, resulting in drag pressure, increased torque, and discontinuous or limited drilling pressure transmitted to the drill bit. Relying solely on the weight of the drill string in the vertical well section is difficult to advance, the tool face is difficult to control, the length of the horizontal section drilled is limited, and the mechanical penetration rate is low. Introducing a pressure pulse generating tool and a matching axial vibration generating tool into the downhole string, by periodically changing the fluid flow area to generate pressure pulses, these pressure pulses act on the matching axial vibration generating tool, driving the drill string to generate axial creep, reducing the friction coefficient between the string and the wellbore wall during sliding drilling, reducing the friction resistance of the string, eliminating the drill string support pressure phenomenon, improving the drilling pressure transmission effect, and increasing the efficiency of directional drilling.

[0003] Chinese patent document CN105089501A discloses a hydraulic oscillator, CN106639944A discloses a turbine-type downhole hydraulic oscillator, CN106761413A discloses a hydraulic oscillator, and Chinese patent document CN206280029U discloses a hydraulic oscillator. These hydraulic oscillators all include a pulse system that uses a short turbine to drive a valve group to generate hydraulic pulses. During the directional drilling process, the pulse system of the turbine-type hydraulic oscillator mentioned above is always in operation. However, under complex drilling conditions, the drill string rotates and there is no pressure support on the drill string. In this case, although the operation of the hydraulic oscillator has little effect on the drilling operation, the operation of the hydraulic oscillator will aggravate the erosion of the valve group. Therefore, keeping the hydraulic oscillator in operation at all times will shorten the life of the pulse system and seriously affect the friction reduction and pressure prevention effect of the tool in the later stage of use. Summary of the Invention

[0004] To address the aforementioned technical issues, the present invention proposes a state-adaptive turbine pulse generator. This generator automatically brakes or rotates the turbine shaft by switching between rotating and non-rotating drillstring states, enabling automated control of the turbine hydraulic oscillator pulse generator's operating state. Specifically, the pulse generator stops operating under complex drilling conditions and starts operating under sliding drilling conditions. This significantly extends the life of the valve block and significantly improves the tool's drag reduction and anti-pressure performance during later stages of directional well construction.

[0005] To this end, according to the present invention, a state-adaptive turbine pulse generator is provided, comprising: a pulse generating device, which comprises a turbine housing, a turbine shaft concentrically arranged inside the turbine housing and provided with a central flow channel, a turbine mechanism sleeved on the turbine shaft, and a valve disc mechanism arranged at the lower end of the turbine shaft, the valve disc mechanism comprising a movable valve disc and a static valve disc, the movable valve disc being fixedly connected to the turbine shaft, the turbine mechanism being capable of driving the turbine shaft to rotate under the action of drilling fluid, and causing the turbine shaft to drive the movable valve disc to rotate, thereby causing the flow area of ​​the valve disc mechanism to change periodically to generate pressure pulses; an automatic control mechanism for controlling the working state of the pulse generating device, the automatic control mechanism comprising: an outer cylinder fixedly connected to the upper end of the turbine housing; and two axially spaced valve discs arranged on the outer cylinder. The first slider and the second slider are both arranged to be fixed to the outer cylinder in the circumferential direction and can move axially along the outer cylinder; and a slider driving mechanism is arranged axially between the first slider and the second slider, wherein the inner wall of the upper end of the turbine shaft is provided with a stop block, and the lower end of the second slider is provided with a brake block axially outward to the axial inner side of the stop block, and the slider driving mechanism is configured to make the first slider and the second slider axially relatively close to each other during composite drilling of the drill rod, so that the brake block and the stop block are staggered to brake the turbine shaft, and make the first slider and the second slider axially relatively far away from each other during sliding drilling of the drill rod, so that the brake block and the stop block are disengaged, so that the turbine shaft rotates under the action of the turbine mechanism to generate a pressure pulse.

[0006] In one embodiment, the slider driving mechanism includes two symmetrically arranged leaf springs and two corresponding centrifugal blocks. The centrifugal blocks are fixedly arranged on the radial outside of the corresponding leaf springs. The two ends of the leaf springs are respectively fixedly connected to the first slider and the second slider. The slider driving mechanism can make the centrifugal blocks generate centrifugal force during composite drilling of the drill rod, and make the leaf springs bend and deform and expand radially, so that the first slider and the second slider are axially relatively close, so that the brake block and the stop block are misaligned.

[0007] In one embodiment, the first slider and the second slider are both circumferentially fixedly connected to the outer cylinder via a spline structure.

[0008] In one embodiment, a limiting step with an upward end face is provided on the inner wall surface of the inner cylinder where the second sliding block is installed, so as to form an axial limit for the second sliding block during assembly.

[0009] In one embodiment, the turbine mechanism includes a stator fixedly connected to the turbine housing and a rotor fixedly connected to the turbine shaft. The rotor can rotate relative to the stator under the action of drilling fluid, thereby driving the turbine shaft to rotate.

[0010] In one embodiment, the static valve disc is provided with a first eccentric hole, and the movable valve disc is provided with a second eccentric hole, and the overlapping portion thereof changes periodically, so that the flow area formed by the valve disc mechanism through the first eccentric hole and the second eccentric hole changes periodically.

[0011] In one embodiment, the apertures and eccentricities of the first eccentric hole and the second eccentric hole are set to be the same.

[0012] In one embodiment, a lower joint is provided at the lower end of the turbine housing, and an upper end of the lower joint faces the static valve disc to form an axial limit.

[0013] In one embodiment, the first slider and the second slider are both provided with axially extending water holes for allowing drilling fluid to flow.

[0014] In one embodiment, a through hole is provided on the side wall of the turbine shaft at the lower end of the vortex mechanism for connecting the central flow channel of the turbine shaft with the radial annulus formed between the turbine shaft and the turbine housing.

[0015] Compared with the existing technology, the advantages of this application are: in extended reach and horizontal well drilling, the state-adaptive turbine pulse generator provided by the present invention, together with the vibration generating tool connected to it, is added to the directional motor drill assembly, causing the drill assembly to produce periodic mild vibration, which in turn causes the drill assembly to generate axial creep, converting static friction into dynamic friction. This significantly reduces the friction between the sliding drilling well wall and the drill pipe, improves the transmission of bit pressure, and greatly increases the mechanical penetration rate and the extension capacity of extended reach and horizontal wells, thus solving the problem of difficult tool face control. The operating state of the turbine pulse generator is automatically controlled by the rotation state of the drill string. During composite drilling, the turbine pulse generator stops operating; during sliding drilling, the turbine pulse generator starts operating and generates high-frequency pulses. This significantly increases the lifespan of the hydraulic oscillator and its drag reduction effect, making directional drilling operations safer and more efficient. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The present invention will be described below with reference to the accompanying drawings.

[0017] Figure 1 The structure of a state-adaptive turbo pulse generator according to the present invention is shown.

[0018] Figure 2 Shows Figure 1The state of the automatic control mechanism in the adaptive turbine pulse generator during drill rod composite drilling is shown.

[0019] In this application, all drawings are schematic drawings, which are only used to illustrate the principles of the present invention and are not drawn to scale. DETAILED DESCRIPTION

[0020] The present invention will be described in detail below with reference to the accompanying drawings. This detailed description should not be considered as limiting the present invention, but should be understood as a more detailed description of certain aspects, features and embodiments of the present invention.

[0021] It will be apparent to those skilled in the art that various modifications and variations may be made to the specific embodiments described herein without departing from the scope or spirit of the invention. Other embodiments will be apparent to those skilled in the art from the description of the invention. The present description and examples are intended to be illustrative only.

[0022] like Figure 1 The figure shows the overall structure of a state-adaptive turbine pulse generator 100 according to the present invention. In the embodiment shown in this figure, the adaptive turbine pulse generator 100 comprises an automatic control mechanism 1 and a pulse generator 2. The outer cylinder 11 of the automatic control mechanism 1 is fixedly connected to the turbine housing 21 of the pulse generator 2. To facilitate installation and removal, this embodiment preferably employs a threaded connection to securely connect the outer cylinder 11 and the turbine housing 21.

[0023] A first slider 12, a slider drive structure 13, and a second slider 14 are disposed within the outer cylinder 11. The slider drive structure 13 is disposed between the first and second sliders 12, 14 and is fixedly connected to them, respectively. In one embodiment, the first and second sliders 12, 14 are circumferentially fixedly connected to the outer cylinder 11 via a spline structure, preventing relative rotation between them. The first and second sliders 12, 14 are able to move axially along the outer cylinder 11 under the control of the slider drive structure 13.

[0024] According to the present invention, the slider driving structure 13 includes: a leaf spring 131 and a centrifugal block 132. The two ends of the leaf spring 131 are respectively fixedly connected to the first slider 12 and the second slider 14, and the centrifugal block 132 is fixed on the outside of the leaf spring 131, and is used to use centrifugal force to make the leaf spring 131 bend and deform and expand radially, so that the first slider 12 and the second slider 14 are axially relatively close. In one embodiment, the slider driving structure 13 includes two leaf springs 131 and two corresponding centrifugal blocks 132, and the two leaf springs 131 are symmetrically arranged. Two leaf springs 131 and two corresponding centrifugal blocks 132 are each provided to ensure that the outer cylinder 11 rotates smoothly. In addition, the two leaf springs 131 must be in a symmetrical arrangement to ensure that the outer cylinder 11 rotates smoothly. The centrifugal block 132 is arranged at the center position of the leaf spring 131 to ensure that the leaf spring 131 begins to deform from the center position under the action of centrifugal force, thereby improving the stability of rotation.

[0025] In a specific embodiment of the present invention, an internal spline is provided in the outer cylinder 11 at a position corresponding to the installation of the first slider 12. The internal spline is used to limit the rotation of the first slider 12 relative to the outer cylinder 11, limiting the first slider 12 to axial movement only inside the outer cylinder 11.

[0026] An internal spline is provided within the outer cylinder 11 at the location corresponding to the second slider 14. This spline is used to limit the rotation of the second slider 14 relative to the outer cylinder 11, restricting the second slider 14 to axial movement within the outer cylinder 11. Furthermore, a limiting step 15 with an upwardly facing end face is provided on the inner wall of the outer cylinder 11 corresponding to the second slider 14 to axially limit the second slider 14 during assembly.

[0027] In a specific embodiment of the present invention, water holes are provided on both the first slider 12 and the second slider 14 , and the water holes are used for the flow of drilling fluid.

[0028] A turbine shaft 22 is concentrically disposed within the turbine housing 21. A turbine mechanism is provided on the turbine shaft 22 for driving the rotation of the turbine shaft 22. The turbine mechanism includes a stator 23 and a rotor 24. The stator 23 is fixedly connected to the turbine housing 21, and the rotor 24 is fixedly connected to the turbine shaft 22. The stator 23 and rotor 24 cooperate to rotate the rotor 24 under the driving force of the drilling fluid, thereby driving the rotation of the turbine shaft 22. To improve the driving efficiency of the drilling fluid, a multi-stage stator 23 and rotor 24 are provided on the turbine shaft 21. Together, the multi-stage stator 23 and rotor 24 drive the rotation of the turbine shaft 22 under the action of the drilling fluid. In this embodiment, to facilitate the flow of the drilling fluid, the turbine shaft 22 has a hollow structure with an axially extending central flow channel at its center for the circulation of the drilling fluid.

[0029] In addition, the second slider 14 is used to brake the turbine shaft 22, and the lower end of the second slider 14 is provided with a brake block 141 extending axially outward. The inner wall of the upper end of the turbine shaft 22 is provided with a block 221. The brake block 141 extends to the axial inner side of the block 121. The brake block 141 can move axially under the action of the slider drive structure 13, thereby approaching the block 121 and interlocking with the block 121 to brake the turbine shaft 22. Specifically, when the drill rod is compositely drilled, the centrifugal block 132 of the slider drive structure 13 generates centrifugal force and causes the leaf spring 131 to bend and deform and expand radially, thereby bringing the first slider 12 and the second slider 14 axially closer to each other, so that the brake block 141 is interlocked with the block. Figure 2 The diagram shows the brake block 141 and the stopper 221 engaged. At this point, the turbine shaft 22 is stationary relative to the outer cylinder 11 and the turbine housing 21, and the pulse generator 2 is in a non-operating state, meaning the drill rod is in a sliding drilling state. When the drill rod is sliding drilling, the drill rod does not rotate, the slider drive structure 13 does not rotate, the centrifugal block 132 generates no centrifugal force, and the leaf spring 131 returns to its original state, pushing the second slider axially downward until it disengages from the stopper 16. At this point, the turbine shaft 22 rotates under the action of the turbine mechanism, thereby driving the movable valve disc 25 (see below) of the valve disc mechanism, thereby generating a pressure pulse.

[0030] The end of the turbine shaft 22 is fixedly connected to a valve disc mechanism, consisting of a movable valve disc 25 and a stationary valve disc 26. The movable valve disc sits on the upper end surface of the stationary valve disc 26, and the movable valve disc 25 is threadedly connected to the turbine shaft 22 for easy installation and removal. To ensure smooth operation and minimize accidents, the threads are tightened in the same direction as the turbine shaft 22's rotation. This prevents the threads from loosening as the turbine shaft 22 rotates.

[0031] The movable valve disc 25 and the static valve disc 26 are each machined with a first eccentric hole and a second eccentric hole of the same diameter and eccentricity. The movable valve disc 25 and the static valve disc 26 are positioned adjacent to each other, with the first and second eccentric holes facing each other. When the movable valve disc 25 rotates relative to the static valve disc 26, the overlapping area of ​​the two valve holes changes periodically, thereby changing the flow area of ​​the drilling fluid and generating high-frequency pressure pulses. In addition, a lower connector 27 is provided at the end of the turbine housing 21 to fix the axial position of the static valve disc 26. The lower connector 27 is threadedly connected to the turbine housing 21. The lower connector 27 is used to connect other downhole drilling tools.

[0032] In this embodiment, drilling fluid flows through the water holes of the first and second sliders 12 and 14, with a portion flowing into the central flow channel of the turbine shaft 22. The remaining portion flows through the stator 23 and rotor 24, thereby driving the stator 23 and rotor 24 to rotate relative to each other. Several circumferentially distributed through-holes are provided on the sidewall of the turbine shaft 22, located below the vortex mechanism, to connect the central flow channel of the turbine shaft 22 with the radial annulus formed between the turbine shaft 22 and the turbine housing 21. The drilling fluid flowing between the stator 23 and rotor 24 drives the rotor 24 to rotate, ultimately flowing through the radial annulus and through-holes into the central flow channel of the turbine shaft 22. The drilling fluid entering the central flow channel then passes through the flow channel formed by the first eccentric hole of the movable valve disc 25 and the second eccentric hole of the static valve disc 26. By varying the diameter of the central flow channel of the turbine shaft 22, the flow rate of drilling fluid entering between the stator 23 and rotor 24 can be varied, thereby varying the rotational speed of the turbine shaft 22. The change in rotational speed also changes the frequency of the interleaving of the eccentric holes on the moving valve disc 25 and the static valve disc 26, which in turn changes the frequency of the pressure pulses of the drilling fluid passing through the eccentric holes, that is, changes the frequency of the pressure pulses of the pulse generator to adapt to the requirements of different working conditions on site.

[0033] During actual operation, when the drill string is drilling, it rotates, causing the outer cylinder 11 to rotate the centrifugal weight 132. The resulting centrifugal force bends and deforms the leaf spring 131, causing it to expand radially. This deformation of the leaf spring 131 drives the first and second sliders 12 and 14 toward each other. When the second slider 14 reaches a certain position, the brake block 141 on the second slider 14 engages with the stopper 221 on the inner wall of the upper end of the turbine shaft 22, stopping the turbine shaft 22 from rotating. This in turn stops the movable valve disc 25 mounted on the turbine shaft 22, preventing relative rotation between the movable and stationary valve discs 26. The pulse generator no longer generates pressure pulses, eliminating erosion caused by water hammer pressure on the valve block and improving the erosion life of the valve block. When the drill string stops rotating, the outer cylinder 11 stops the centrifugal weight 132, dissipating the centrifugal force. The spring force of the leaf spring 131 pushes the first and second sliders 12 and 14 axially apart. The brake block 141 on the second slider 14 is disengaged from the stopper 221 in the turbine shaft water eyelet, and the turbine shaft 22 continues to rotate under the action of the drilling fluid, thereby driving the valve disc 25 to rotate. At this time, the pulse generator will work normally and generate pressure pulses.

[0034] The state-adaptive turbine pulse generator 100 according to the present invention can be used in the drilling of extended reach wells and horizontal wells. The state-adaptive turbine pulse generator 100 is added to the directional motor drill assembly together with the vibration generating tool connected to it, so that the drill assembly generates periodic mild vibration. This causes the drill assembly to generate axial creep, converting static friction into dynamic friction, reducing friction between the sliding drilling well wall and the drill pipe, improving the transmission of drilling pressure, increasing the mechanical drilling speed and the extension capacity of extended reach wells and horizontal wells, and solving the problem of difficult tool face control. The state-adaptive turbine pulse generator 100 can automatically control the working state of the turbine pulse generator 2 through the automatic control mechanism 1 according to the actual working conditions on site. When the drill pipe is composite drilling, the turbine pulse generator 2 is controlled to stop working; when the drill pipe is sliding drilling, the turbine pulse generator 2 is controlled to start working and generate high-frequency pulses, greatly improving the life of the hydraulic oscillator and the drag reduction effect, making directional drilling construction safer and more efficient.

[0035] Finally, it should be noted that the above description is merely a preferred embodiment of the present invention and does not constitute any limitation to the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments or to replace some of the technical features therein with equivalents. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included in the scope of protection of the present invention.

Claims

1. A state-adaptive turbine pulse generator, comprising: A pulse generating device (2), comprising a turbine housing (21), a turbine shaft (22) concentrically arranged inside the turbine housing and provided with a central flow channel, a turbine mechanism sleeved on the turbine shaft, and a valve disc mechanism arranged at the lower end of the turbine shaft, the valve disc mechanism comprising a movable valve disc (25) and a static valve disc (26), the movable valve disc being fixedly connected to the turbine shaft, the turbine mechanism being capable of driving the turbine shaft to rotate under the action of drilling fluid, and causing the turbine shaft to drive the movable valve disc to rotate, thereby causing the flow area of ​​the valve disc mechanism to change periodically to generate pressure pulses; An automatic control mechanism (1) for controlling the working state of the pulse generating device, the automatic control mechanism comprising: An outer cylinder (11) fixedly connected to the upper end of the turbine housing; A first slider (12) and a second slider (14) are axially spaced apart from each other and are disposed in the outer cylinder, wherein the first slider and the second slider are both circumferentially fixed to the outer cylinder and are movable axially along the outer cylinder; and A slider driving mechanism (13) is arranged axially between the first slider and the second slider, the slider driving mechanism comprising two symmetrically arranged leaf springs (131) and corresponding two centrifugal blocks (132), the centrifugal blocks being fixedly arranged on the radially outer sides of the corresponding leaf springs, the two ends of the leaf spring being fixedly connected to the first slider and the second slider respectively, wherein the inner wall of the upper end of the turbine shaft is provided with a stop block, and the lower end of the second slider is provided with a brake block (141) extending axially outward to the axial inner side of the stop block, the slider driving mechanism is configured to make the first slider and the second slider axially close to each other during composite drilling of the drill rod, so that the brake block and the stop block are mismatched to brake the turbine shaft, and to make the first slider and the second slider axially move away from each other during sliding drilling of the drill rod, so that the brake block and the stop block are disengaged, thereby causing the turbine shaft to rotate under the action of the turbine mechanism to generate a pressure pulse.

2. The state-adaptive turbine pulse generator according to claim 1, characterized in that: The first slider and the second slider are both circumferentially fixedly connected to the outer cylinder via a spline structure.

3. The state-adaptive turbine pulse generator according to claim 1, characterized in that: A limiting step (15) with an upward end face is provided on the inner wall surface of the outer cylinder where the second sliding block is installed, for forming an axial limit for the second sliding block during assembly.

4. The state-adaptive turbine pulse generator according to claim 1, characterized in that: The turbine mechanism comprises a stator (23) fixedly connected to the turbine housing and a rotor (24) fixedly connected to the turbine shaft. The rotor can rotate relative to the stator under the action of drilling fluid, thereby driving the turbine shaft to rotate.

5. The state-adaptive turbine pulse generator according to claim 1, characterized in that: The static valve disc is provided with a first eccentric hole, and the movable valve disc is provided with a second eccentric hole. The overlapping portion thereof changes periodically, so that the flow area formed by the valve disc mechanism through the first eccentric hole and the second eccentric hole changes periodically.

6. The state-adaptive turbine pulse generator according to claim 5, characterized in that: The hole diameters and eccentric distances of the first eccentric hole and the second eccentric hole are set to be the same.

7. The state-adaptive turbine pulse generator according to claim 1, characterized in that: A lower joint (27) is provided at the lower end of the turbine housing (21), and the upper end of the lower joint faces the static valve disc to form an axial limit.

8. The state-adaptive turbine pulse generator according to claim 1, characterized in that: The first slider (12) and the second slider (14) are both provided with axially extending water holes for allowing drilling fluid to circulate.

9. The state-adaptive turbine pulse generator according to claim 1, characterized in that: A through hole is provided on the side wall of the turbine shaft at the lower end of the turbine mechanism for connecting the central flow channel of the turbine shaft with the radial annulus formed between the turbine shaft and the turbine housing.

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