A pulse vortex cementing agitator and its application method

Abstract

This invention relates to the field of oil and gas exploration and development technology, and particularly to a pulse vortex cementing agitator and its usage method. The pulse vortex cementing agitator includes a housing, a guide shoe cap rotatably connected to the bottom of the housing, an installation plate inside the housing, a piston cylinder with an upper opening forming an annulus with the housing, an inclined vortex hole communicating with the annulus on the top of the installation plate, and an upper side hole communicating with the annulus on the upper side wall of the piston cylinder. A rotating shaft rotatably passes through the piston cylinder and the installation plate at its bottom, and a hydraulically driven upper rotating disk at the top of the rotating shaft. The upper rotating disk has a first inclined hole communicating with the piston cylinder and a second inclined hole communicating with the annulus. The rotating shaft is connected to the piston via a cam mechanism. When the rotating shaft rotates, the piston rises and falls vertically along the piston cylinder, sealing or unsealing the upper side hole. This invention, by combining pulse agitation and vortex flow, significantly improves the uniformity of cementing fluid distribution and cementing quality. The eccentric guide shoe cap rotatably connects to the housing, improving the efficiency of cementing string installation.

Description

Technical Field

[0001] This invention relates to the field of oil and gas exploration and development technology, and in particular to a pulse vortex cementing agitator and its application method. Background Technology

[0002] In oil drilling, cementing fluid needs to be injected into the annular space between the wellbore and the casing for cementing. Cementing is a crucial operation in the drilling process, and its quality significantly affects the safety of subsequent oil production. Patent application CN201720621600.9 discloses a cementing vibration device, which includes a pipe joint, a mandrel, an upper orifice plate, a lower orifice plate, an impeller, an eccentric cam, and a guide shoe. The mandrel is located inside the pipe joint, and an upper annular platform is provided on the upper inner wall of the pipe joint. An upper orifice plate is fitted onto the inner side of the upper part of the pipe joint, with the outer upper end of the upper orifice plate abutting against the lower end of the upper annular platform. An upper central hole is provided in the middle of the upper orifice plate, and the upper end of the mandrel passes through and is located above the upper central hole. An upper limit stop is provided between the upper central hole and the mandrel, allowing the mandrel to rotate freely relative to the upper orifice plate while restricting the downward movement of the upper orifice plate. The above-mentioned technical solution uses the rotation of an impeller to rotate a mandrel, which in turn drives an eccentric cam. Due to the uneven mass distribution of the eccentric cam, its rotation generates high-frequency, low-amplitude vibrations, ensuring uniform distribution of cement slurry and preventing sedimentation, thus achieving good cementing quality. However, this technical solution has the following problems: First, the vibration device only uses the vibration generated by the rotation of the eccentric cam to uniformly distribute the cement slurry (i.e., cementing fluid), resulting in limited vibration effect. The cement slurry is still prone to sedimentation, limiting its improvement in cementing quality. Second, the guide shoe and pipe joint are bolted together, forming a fixed connection. During the well run-in process, the guide shoe cannot rotate to avoid sand bridges or obstacles, affecting construction efficiency.

[0003] In summary, there is an urgent need to provide a cementing vibration device that can significantly improve the uniformity of cementing fluid distribution and cementing quality, while also increasing the efficiency of cementing string installation. Summary of the Invention

[0004] To solve at least one of the above-mentioned technical problems, the present invention provides a pulse vortex cementing agitator, comprising a housing, a guide shoe cap rotatably connected to the bottom of the housing, an installation plate inside the housing, a piston cylinder with an upper opening at the top of the installation plate forming an annulus with the housing, an inclined vortex hole communicating with the annulus on the installation plate, an upper side hole communicating with the annulus on the upper side wall of the piston cylinder, a rotating shaft rotatably penetrating the piston cylinder and the installation plate at the bottom, and an upper rotating disk hydraulically driven to rotate at the top of the rotating shaft, the upper rotating disk having a first inclined hole communicating with the piston cylinder and a second inclined hole communicating with the annulus, the rotating shaft being connected to the piston via a cam mechanism, and the piston vertically rising and falling along the piston cylinder when the rotating shaft rotates, sealing or unsealing the upper side hole.

[0005] Preferably, the housing includes a threaded upper shell and a lower shell, the inner walls of the upper shell and the lower shell are joined to form an annular groove, and the side wall of the mounting plate is provided with an annular flange that can be inserted into the annular groove; the shoe cap includes a connecting part that is rotatably connected to the housing and an eccentric ball head whose center of gravity is off-axis, the side wall of the eccentric ball head is provided with a plurality of downwardly inclined side spray holes at equal intervals, and the bottom of the eccentric ball head is provided with a bottom spray hole.

[0006] Preferably, the outer wall of the upper turntable rotates and abuts against the housing, and the bottom of the upper turntable rotates and abuts against the top of the piston cylinder. Multiple first and second oblique holes are provided at equal intervals around the circumference of the rotating shaft. Both the first and second oblique holes are inclined along the circumference of the upper turntable, and the flow rate of the first oblique hole is greater than that of the second oblique hole.

[0007] Preferably, the piston cylinder has a lower side hole on its side wall, and multiple upper and lower side holes are provided at equal intervals along the circumference of the piston cylinder. When the piston rises and falls, the upper and lower side holes are alternately blocked. The upper end face of the mounting plate has a centering groove for mounting the piston cylinder.

[0008] Preferably, the cam mechanism includes an elliptical groove on the outer wall of the rotating shaft that is inclined downwards and a slider on the inner wall of the piston that slides in cooperation with the groove; the piston includes a body that can slide against the inner wall of the piston cylinder, a guide groove is vertically provided on the outer wall of the body, a guide block is provided on the inner wall of the piston cylinder that slides in cooperation with the guide groove, a core groove is provided at the center of the top of the body, two semi-circular cores are provided in the core groove, a hemispherical slider is provided on the inner wall of one core, and the core is connected to the body by screws.

[0009] Preferably, the top of the core is provided with an outwardly extending semi-circular insertion ring. The upper surface of one free end of the insertion ring is provided with a slot, and the upper surface of the other free end is provided with an insertion block corresponding to the slot. The slot and the insertion block are provided with corresponding insertion holes. The insertion rings, slots and insertion blocks on the two cores can be inserted into a ring shape. The top of the body is provided with an insertion groove for accommodating the insertion ring. The insertion groove is provided with a threaded groove corresponding to the insertion hole. The screw passes through the insertion hole and is screwed into the threaded groove.

[0010] Preferably, the mounting plate has a circular central groove at its center, and the central turntable is mounted in the central groove via a turntable bearing. The outer wall of the central turntable has a first annular groove, and the mounting plate has a connecting hole that connects the annular cavity and the first annular groove. The inner wall of the central turntable has a second annular groove, and the inner circumference of the central turntable has multiple flow channels that connect the first and second annular grooves at equal intervals. The flow channels are offset from the radial line of the central turntable. The rotating shaft has a cavity inside, and the upper side wall of the cavity has an upper through hole that communicates with the second annular groove, and the lower side wall of the cavity has a lower through hole.

[0011] Preferably, the rotating shaft is provided with a turbine, the turbine including a central ring connected to the rotating shaft and hollow blades equidistantly arranged around the circumference of the central ring, the inner sidewall of the central ring is provided with a third annular groove connecting the cavity of the hollow blades and the lower through hole, and the bottom of the hollow blades is provided with a liquid outlet hole.

[0012] Preferably, the bottom of the rotating shaft is connected to the lower turntable, the outer wall of the lower turntable is connected to the inner wall of the shoe cap, and the lower turntable is provided with a third oblique hole and a fourth oblique hole in a radially outward manner to drive the lower turntable to rotate. The third oblique hole and the fourth oblique hole are provided in multiples at equal intervals along the circumference of the rotating shaft. The third oblique hole and the fourth oblique hole are both tapered and gradually expand downward and can deflect the jet towards the side wall of the shoe cap. The flow rate of the third oblique hole is greater than that of the fourth oblique hole.

[0013] This invention provides a method for using a pulse vortex cementing agitator, comprising the following steps:

[0014] Step S1: Connect the top of the casing to the cementing string, and then lower it to the target position in the wellbore;

[0015] Step S2: Inject cementing fluid into the shell. When the cementing fluid flows through the upper rotary table, it drives the upper rotary table and the shaft connected to the upper rotary table to rotate. Part of the cementing fluid flows into the piston cylinder from the first inclined hole, and then flows into the annulus from the upper side hole of the piston cylinder. Another part of the cementing fluid flows into the annulus from the second inclined hole. The cementing fluid in the annulus flows out from the swirling hole set at an inclination on the mounting plate, forming an in-tube swirling flow.

[0016] Step S3: When the shaft rotates, the piston is driven to rise and fall through the cam mechanism. When the piston rises, the cementing fluid flowing into the annulus from the upper hole decreases until it reaches zero. The cementing fluid in the annulus passes through the mounting plate at a low flow rate. When the piston falls, the upper hole is unsealed, and the cementing fluid flowing into the annulus from the upper hole increases. The cementing fluid in the annulus passes through the mounting plate at a high flow rate. The piston continues to rise and fall. The flow rate of the cementing fluid passing through the mounting plate produces periodic high and low changes, forming pulse oscillation. The swirling oscillation and counter-flow in the tube can increase the density and uniformity of the cementing fluid distribution.

[0017] Step S4: The cementing fluid inside the casing enters the guide shoe cap and is eventually ejected from the guide shoe cap in a rotating motion, forming an external vortex. The external vortex can more effectively carry the bottom mud cake and the loose mud cake on the well wall to the wellhead, improving the wellbore purification state and thus improving the cementing quality.

[0018] Compared with the prior art, the present invention has the following beneficial technical effects:

[0019] 1. This invention features a piston cylinder on an mounting plate that forms an annulus with the housing, and an upper rotary table on top of a rotating shaft that rotates under hydraulic drive. When cementing fluid flows through the upper rotary table, it drives the upper rotary table and the rotating shaft connected to it to rotate. The rotating shaft drives the piston to rise and fall via a cam mechanism, sealing or unsealing the upper hole of the piston cylinder. This causes the flow velocity of the cementing fluid to alternately change when it flows through the inclined swirling holes on the mounting plate, creating a pulse oscillation effect and forming swirling turbulence inside the pipe. This allows the cementing fluid to be densely and uniformly distributed, improving cementing quality. Furthermore, when the cementing fluid is horizontally injected into the annulus from the upper hole of the piston cylinder, it can be flushed and mixed with the cementing fluid injected from top to bottom through the second inclined hole, improving the uniformity of the cementing fluid and further enhancing cementing quality.

[0020] 2. The shell and the guide shoe cap are rotatably connected. The cementing fluid passing through the mounting plate can be sprayed out from the guide shoe cap, forming an external vortex, which further improves the cementing quality.

[0021] 3. When the upper and lower shells of the housing are joined together, an annular groove can be formed. The annular flange of the mounting plate can be inserted into the annular groove to fix the mounting plate, which is convenient for installation and maintenance.

[0022] 4. The guide shoe cap has an eccentric ball head with its center of gravity off-axis, which enables the guide shoe cap to rotate eccentrically when it encounters obstacles or sand bridges, and freely rotate to change direction to avoid obstacles, thereby improving the efficiency of casing insertion into the well. The eccentric ball head has several downward-sloping side injection holes equidistantly arranged on the circumference of its sidewall, which can further improve the swirling intensity outside the casing, thereby improving the cementing quality.

[0023] 5. The upper rotary table is disc-shaped, and its outer side wall rotates to abut against the shell. The cementing fluid can only pass through the upper rotary table 7 through the first inclined hole and the second inclined hole. When the cementing fluid flows through the first inclined hole and the second inclined hole, it can drive the upper rotary table to rotate. The flow rate of the first inclined hole is greater than that of the second inclined hole, which can enhance the pulse oscillation effect of the cementing fluid. At the same time, it can improve the flushing and mixing effect of the horizontally flowing cementing fluid and the cementing fluid flowing from top to bottom.

[0024] 6. A lower side hole is provided below the piston cylinder side wall. When the piston rises and falls, the upper side hole and the lower side hole are alternately blocked, which can produce a synergistic effect and further enhance the pulse oscillation effect of the cementing fluid and the flushing and mixing effect of the cementing fluid.

[0025] 7. The piston features a detachable, split structure for easy installation and maintenance. Two insert rings are positioned above the two piston cores, which can be joined to form a circle, sealing the annular gap between the core and the core groove. This prevents cementing fluid from entering the annular gap, improving the piston's service life and lifting stability. The insert rings also feature mating slots and blocks, which, on the one hand, seal the gap between the two cores, further improving the piston's service life and lifting stability; on the other hand, two screws are used to connect the two cores to each other and to the main body, reducing the number of screws used and improving connection stability.

[0026] 8. A central groove is provided at the center of the mounting plate, and a central turntable is installed in the central groove. The central turntable has a flow channel that is offset from the radial line of the central turntable. When the cementing fluid flows through the flow channel and passes through the central turntable, it can drive the shaft to rotate. The central turntable and the upper turntable work together to drive the shaft to rotate, which can further increase the shaft speed and enhance the swirling intensity of the cementing fluid.

[0027] 9. A turbine is installed below the mounting plate. The turbine has hollow blades that are connected to the central turntable. A portion of the cementing fluid impacts the turbine from the outside from the top down through the swirl holes of the mounting plate, while another portion of the cementing fluid flows out of the turbine from the inside out through the hollow blades. The two portions of cementing fluid work together to drive the turbine and the shaft connected to the turbine to rotate faster.

[0028] 10. A lower rotary table is installed below the turbine, which is connected to the guide shoe cap. When the shaft rotates, the lower rotary table and the guide shoe cap can rotate synchronously with the shaft, so that the cementing fluid can be sprayed out in a swirling motion to form a large vortex outside the pipe. The third and fourth inclined holes of the lower rotary table are both tapered and gradually expand downwards, so that the cementing fluid generates a small vortex when it flows out from the third and fourth inclined holes, improving the uniformity of the cementing fluid. At the same time, the third and fourth inclined holes can deflect the jet towards the side wall of the guide shoe cap, impact the guide shoe cap and form a vortex inside the pipe. The swirling motion inside the pipe and the swirling motion outside the pipe work together to further improve the cementing effect.

[0029] In summary, this invention significantly improves the uniformity of cementing fluid distribution and cementing quality by combining pulse oscillation and swirling flow. The eccentric guide shoe cap is rotatably connected to the shell, which can improve the efficiency of cementing string installation. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the structure of the present invention;

[0031] Figure 2 This is a schematic diagram of the installation disk.

[0032] Figure 3 This is a schematic diagram of the piston cylinder structure;

[0033] Figure 4 This is a schematic diagram of the upper turntable structure;

[0034] Figure 5 An exploded view of the piston;

[0035] Figure 6 A schematic diagram of the structure of the central turntable;

[0036] Figure 7 A schematic diagram of the flow channel structure for the central turntable;

[0037] Figure 8 This is a schematic diagram of the turbine structure;

[0038] Figure 9 This is a schematic diagram of the lower turntable.

[0039] Figure 10 This is a schematic diagram of the internal structure of the present invention without the shell and the shoe.

[0040] Explanation of reference numerals in the attached figures:

[0041] 1. Shell; 101. Upper shell; 102. Lower shell; 103. Annular groove; 2. Shoe cap; 201. Connecting part; 202. Eccentric ball head; 203. Side injection hole; 204. Bottom injection hole; 3. Mounting plate; 301. Swirl hole; 302. Annular flange; 303. Centering groove; 304. Central groove; 305. Connecting hole; 4. Piston cylinder; 401. Upper side hole; 402. Lower side hole; 403. Guide block; 5. Annular cavity; 6. Rotating shaft; 601. Slide groove; 602. Cavity; 603. Upper through hole; 604. Lower through hole; 7. Upper turntable; 701. First oblique hole; 702. Second oblique hole; 8. Piston; 801. Body; 802. Guide groove; 803. Core groove; 804. Core; 805. Slider; 806. Screw; 807. Insert ring; 808. Slot; 809. Insert block; 8010. Insertion hole; 8011. Insertion groove; 8012. Threaded groove; 9. Central turntable; 901. First annular groove; 902. Second annular groove; 903. Flow channel; 10. Turntable bearing; 11. Turbine; 1101. Central ring; 1102. Hollow blade; 1103. Third annular groove; 1104. Liquid outlet hole; 12. Lower turntable; 1201. Third oblique hole; 1202. Fourth oblique hole. Detailed Implementation

[0042] The specific embodiments of the present invention are described below with reference to the accompanying drawings and examples:

[0043] It should be noted that the structures, proportions, sizes, etc. shown in the accompanying drawings are only for the purpose of assisting those skilled in the art in understanding and reading the content disclosed in the specification, and are not intended to limit the conditions under which the present invention can be implemented. Any modifications to the structure, changes in the proportions, or adjustments to the size, without affecting the effects and objectives that the present invention can produce, should fall within the scope of the technical content disclosed in the present invention.

[0044] Furthermore, the terms such as "upper," "lower," "left," "right," "middle," and "one" used in this specification are merely for clarity of description and are not intended to limit the scope of the invention. Any changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered within the scope of the invention.

[0045] Example 1

[0046] Combined with appendix Figures 1 to 10 This embodiment provides a pulse vortex cementing agitator, including a housing 1. A guide shoe cap 2 is rotatably connected to the bottom of the housing 1. An installation plate 3 is provided inside the housing 1. The top of the installation plate 3 is provided with a piston cylinder 4 with an upper opening and forming an annulus 5 with the housing 1. The installation plate 3 is provided with an inclined vortex hole 301 communicating with the annulus 5. The side wall of the piston cylinder 4 is provided with an upper side hole 401 communicating with the annulus 5. The bottom of the rotating shaft 6 rotatably passes through the piston cylinder 4 and the installation plate 3. The top of the rotating shaft 6 is provided with a hydraulically driven upper turntable 7. The upper turntable 7 is provided with a first inclined hole 701 communicating with the piston cylinder 4 and a second inclined hole 702 communicating with the annulus 5. The rotating shaft 6 is connected to a piston 8 through a cam mechanism. When the rotating shaft 6 rotates, the piston 8 rises and falls vertically along the piston cylinder 4 to block or unblock the upper side hole 401.

[0047] In the above technical solution, the mounting plate 3 can be fixed in the housing 1 in any suitable manner, including but not limited to screwing and welding. The inclined swirl hole 301 on the mounting plate 3 can cause the cementing fluid flowing through the mounting plate 3 to generate swirl, thereby improving the cementing quality. The swirl hole 301 can be inclined in any suitable manner. When relying solely on the swirl hole 301 to generate swirl, it is preferable to make the swirl hole 301 inclined along the circumference of the mounting plate 3. In this embodiment, the swirl hole 301 is inclined from the outside of the mounting plate 3 towards the center in order to fully impact the turbine 11 below the mounting plate 3 (described in detail later); piston cylinder 4 The upper rotary table 7 can be fixed to the mounting plate 3 in any suitable manner, including but not limited to screwing or welding; the rotating shaft 6 can be rotatably mounted inside the housing 1 in any suitable manner, including but not limited to connecting the rotating shaft 6 to the piston cylinder 4 or to the mounting plate 3 via bearings; the upper rotary table 7 can adopt any suitable structure capable of rotating under hydraulic drive, such as providing turbine blades and / or deflection holes on the disc body; the guide shoe cap 2 can be rotatably connected to the housing 1 in any suitable manner, including but not limited to using bearings; in use, cementing fluid is injected into the housing 1, and the cementing fluid drives the upper rotary table 7 as it flows through it. The rotating upper turntable 7 and the rotating shaft 6 connected to the upper turntable 7 rotate. The rotating shaft 6 drives the piston 8 to rise and fall through the cam mechanism, sealing or unsealing the upper side hole 401 of the piston cylinder 4. When the piston 8 seals the upper side hole 401, the cementing fluid can only be injected into the annulus 5 from top to bottom in the form of a swirling flow through the second inclined hole 702, and then passes through the mounting plate 3 through the swirling hole 301. When the piston 8 unseales the upper side hole 401, the cementing fluid that entered the piston cylinder 4 from the first inclined hole 701 passes through the upper side hole 401 and is injected horizontally into the annulus 5. The flow rate of the cementing fluid through the mounting plate 3 through the swirling hole 301 increases as the piston 8 seals or unseales the upper side hole 401. Unsealing the upper side hole 401 allows the cementing fluid to flow through the mounting plate 3 at alternating speeds, generating a pulse oscillation effect and creating an internal swirling flow. This ensures a dense and uniform distribution of the cementing fluid, improving cementing quality. Furthermore, when the cementing fluid is horizontally injected into the annulus 5 from the upper side hole 401 of the piston cylinder 4, it can be flushed and mixed with the cementing fluid that is rotary injected from the second inclined hole 702 from top to bottom, improving the uniformity of the mixing of solids and liquids in the cementing fluid and further enhancing cementing quality. The guide shoe cap 2 is rotatably connected to the shell 1, so the cementing fluid passing through the mounting plate 3 can be rotary ejected from the guide shoe cap 2, forming an external swirling flow.

[0048] The pulse vortex cementing agitator in this embodiment achieves simultaneous vortex generation inside and outside the pipe. The vortex agitation inside the pipe and the counter-flushing can increase the density and uniform distribution of the cementing fluid, while the vortex outside the pipe can more effectively carry the bottom mud cake and the loose mud cake on the well wall to the wellhead, improve the wellbore purification state, and thus improve the cementing quality.

[0049] In one specific technical solution, the housing 1 includes an upper shell 101 and a lower shell 102 connected by threads. The inner walls of the upper shell 101 and the lower shell 102 are joined to form an annular groove 103. The side wall of the mounting plate 3 is provided with an annular flange 302 that can be inserted into the annular groove 103. The shoe cap 2 includes a connecting part 201 that is rotatably connected to the housing 1 and an eccentric ball head 202 whose center of gravity is off the axis. The side wall of the eccentric ball head 202 is provided with a plurality of downwardly inclined side spray holes 203 at equal intervals. The bottom of the eccentric ball head 202 is provided with a bottom spray hole 204.

[0050] In the above technical solution, when the upper shell 101 and lower shell 102 of the housing 1 are joined, an annular groove 103 can be formed. The annular flange 302 of the mounting plate 3 can be inserted into the annular groove 103 to fix the mounting plate 3, which is convenient for installation and maintenance. When the annular groove 103 is provided, a groove with an opening at the top can be provided on the inner side wall of the lower shell 102, or as in this embodiment. Figure 1 As shown, a groove with an open bottom is provided on the inner wall of the upper shell 101. In this embodiment, the annular flange 302 of the mounting plate 3 is first inserted into the groove on the inner wall of the upper shell 101, and the upper end face of the annular flange 302 abuts against the highest point of the groove of the upper shell 101. Then, the lower shell 102 is screwed to the upper shell 101, and the lower end face of the annular flange 302 abuts against the inner wall of the lower shell 102. Preferably, a limiting groove is provided on the annular flange 302, and a limiting block that is inserted and matched with the limiting groove is provided in the annular groove 103 to prevent the mounting plate 3 from circumferentially sliding and further improve the connection stability. The bottom of the shell 1 is rotatably connected to an eccentric guide shoe cap 2. The eccentrically rotating guide shoe cap 2 can rotate freely to change direction to avoid obstacles and improve the casing insertion efficiency. In addition, the eccentric ball head 202 has several downwardly inclined side injection holes 203 equidistantly arranged on the circumference of its side wall, which can further improve the external swirling intensity and thus improve the cementing quality.

[0051] In one specific technical solution, the outer wall of the upper turntable 7 rotates and abuts against the housing 1, and the bottom of the upper turntable 7 rotates and abuts against the top of the piston cylinder 4. Multiple first inclined holes 701 and second inclined holes 702 are provided at equal intervals around the circumference of the rotating shaft 6. The first inclined holes 701 and second inclined holes 702 are both inclined along the circumference of the upper turntable 7. The flow rate of the first inclined hole 701 is greater than that of the second inclined hole 702.

[0052] In the above technical solution, the upper rotary table 7 is disc-shaped, and its outer side wall rotates to abut against the housing 1. The cementing fluid can only pass through the upper rotary table 7 through the first inclined hole 701 and the second inclined hole 702. The first inclined hole 701 and the second inclined hole 702 are both inclined along the circumference of the upper rotary table 7. When the cementing fluid flows through the first inclined hole 701 and the second inclined hole 702, it can drive the upper rotary table 7 to rotate. The flow rate of the first inclined hole 701 is greater than that of the second inclined hole 702, which can enhance the pulse oscillation effect of the cementing fluid. At the same time, it can improve the flushing and mixing effect of the horizontally flowing cementing fluid and the cementing fluid flowing from top to bottom.

[0053] In one specific technical solution, a lower side hole 402 is provided below the side wall of the piston cylinder 4, and multiple upper side holes 401 and lower side holes 402 are provided at equal intervals along the circumference of the piston cylinder 4. When the piston 8 rises and falls, it alternately blocks the upper side hole 401 and the lower side hole 402. The upper end face of the mounting plate 3 is provided with a centering groove 303 for mounting the piston cylinder 4.

[0054] In the above technical solution, a lower side hole 402 is provided below the side wall of the piston cylinder 4. When the piston 8 rises and falls, it alternately blocks the upper side hole 401 and the lower side hole 402, which can produce a synergistic effect and further enhance the pulse oscillation effect and the flushing and mixing effect of the cementing fluid. During the process of the piston 8 rising to block the upper side hole 401 and unblocking the lower side hole 402, the flow velocity of the cementing fluid through the mounting plate 3 gradually decreases, the distance between the piston 8 and the bottom of the piston cylinder 4 increases, generating negative pressure, and some of the cementing fluid in the annulus 5 enters the bottom of the piston cylinder 4 from the lower side hole 402, further reducing the flow velocity of the cementing fluid through the mounting plate 3. Low; during the process of piston 8 descending to unseal the upper side hole 401 and seal the lower side hole 402, the flow velocity of cementing fluid through the mounting plate 3 gradually increases. At the same time, piston 8 presses down to allow cementing fluid at the bottom of piston cylinder 4 to be horizontally injected into the annulus 5 through the lower side hole 402, further increasing the flow velocity of cementing fluid through the mounting plate 3 and further improving the flushing and mixing effect of horizontally flowing cementing fluid and downward-flowing cementing fluid. Thus, under the synergistic effect of upper side hole 401, lower side hole 402 and piston 8, the pulse oscillation effect of cementing fluid and the flushing and mixing effect of cementing fluid are further improved.

[0055] In one specific technical solution, the cam mechanism includes an elliptical groove 601 located on the outer wall of the rotating shaft 6 and inclined downwards, and a slider 805 located on the inner wall of the piston 8 and slidingly engaged with the groove 601; the piston 8 includes a body 801 that can slide against the inner wall of the piston cylinder 4, a guide groove 802 vertically provided on the outer wall of the body 801, a guide block 403 slidably engaged with the guide groove 802 on the inner wall of the piston cylinder 4, a core groove 803 at the top center of the body 801, two semi-circular cores 804 provided in the core groove 803, a hemispherical slider 805 provided on the inner wall of one core 804, and the core 804 and the body 801 connected by screws 806.

[0056] In the above technical solution, the downwardly inclined elliptical slide 601 refers to the slide 601 rotating once from the outer wall of the rotating shaft 6 downward and then upward. Through the sliding cooperation between the downwardly inclined elliptical slide 601 and the slider 805, the rotating shaft 6 can drive the piston 8 to rise and fall when rotating, thus achieving the cam drive function while maintaining a compact overall structure. The piston 8 is a detachable split structure, which is convenient for installation.

[0057] In one specific technical solution, the top of the core 804 is provided with an outwardly extending semi-circular insertion ring 807. The upper surface of one free end of the insertion ring 807 is provided with a slot 808, and the upper surface of the other free end is provided with an insertion block 809 corresponding to the slot 808. The slot 808 and the insertion block 809 are respectively provided with insertion holes 8010. The insertion ring 807, slot 808 and insertion block 809 on the two cores 804 can be inserted into a ring shape. The top of the body 801 is provided with an insertion groove 8011 to accommodate the insertion ring 807. The insertion groove 8011 is provided with a threaded groove 8012 corresponding to the insertion hole 8010. The screw 806 passes through the insertion hole 8010 and is screwed into the threaded groove 8012.

[0058] In the above technical solution, the two plug rings 807 can be spliced ​​into a circle to seal the annular gap between the core 804 and the core groove 803, preventing cementing fluid from entering the annular gap between the core 804 and the core groove 803, thereby improving the service life and lifting stability of the piston 8. The plug rings 807 are provided with mutually cooperating slots 808 and plug blocks 809, which can seal the gap between the two cores 804 on the one hand, improving the service life and lifting stability of the piston 8 on the other hand, and can achieve the connection between the two cores 804 and between the two cores 804 and the body 801 through two screws 806, reducing the number of screws 806 used and improving the connection stability.

[0059] In one specific technical solution, the mounting plate 3 has a circular central groove 304 at its center, and the central turntable 9 is mounted in the central groove 304 via a turntable bearing 10. The outer side wall of the central turntable 9 has a first annular groove 901, and the mounting plate 3 has a connecting hole 305 connecting the annular cavity 5 and the first annular groove 901. The inner side wall of the central turntable 9 has a second annular groove 902, and the inner circumference of the central turntable 9 has a plurality of flow channels 903 equidistantly arranged to connect the first annular groove 901 and the second annular groove 902. The flow channels 903 are offset from the radial line of the central turntable 9. The rotating shaft 6 has a cavity 602 inside, and the upper side wall of the cavity 602 has an upper through hole 603 communicating with the second annular groove 902. The lower side wall of the cavity 602 has a lower through hole 604.

[0060] In the above technical solution, the central turntable 9 can work together with the upper turntable 7 to drive the rotating shaft 6 to rotate, thereby increasing the rotation speed of the rotating shaft 6 and enhancing the swirling intensity of the cementing fluid. It should be noted that in this invention, the rotation of the rotating shaft 6 is driven in the same direction, and the same applies below. During use, some cementing fluid enters the connecting hole 305 of the mounting plate 3 from the annulus 5, flows through the first annular groove 901, the flow channel 903 and the second annular groove 902 of the central turntable 9 and enters the cavity 602 of the rotating shaft 6. Finally, it flows out from the lower through hole 604 of the rotating shaft 6. When the cementing fluid flows in the flow channel 903, it will drive the central turntable 9 and the rotating shaft 6 connected to the central turntable 9 to rotate. When the cementing fluid is ejected from the lower through hole 604, it can rotate and impact the inner wall of the housing 1.

[0061] In one specific technical solution, the rotating shaft 6 is provided with a turbine 11. The turbine 11 includes a central ring 1101 connected to the rotating shaft 6 and hollow blades 1102 equidistantly arranged around the circumference of the central ring 1101. The inner sidewall of the central ring 1101 is provided with a third annular groove 1103 that connects the cavity of the hollow blades 1102 and the lower through hole 604. The bottom of the hollow blades 1102 is provided with a liquid outlet hole 1104.

[0062] In the above technical solution, the turbine 11 can further enhance the rotational speed of the shaft 6 and improve the cementing effect; the hollow blade 1102 of the turbine 11 has a hollow structure, that is, its internal cavity is basically consistent with the external shape of the hollow blade 1102. When the cementing fluid flows in the cavity, it can drive the turbine 11 to rotate from the inside; in use, the cementing fluid flows from top to bottom through the vortex hole 301 through the turbine 11, and at the same time, it can also flow from the inside to the outside through the lower through hole 604 through the turbine 11. The two cementing fluids work together to drive the turbine 11 and the shaft connected to the turbine 11 to rotate faster.

[0063] In one specific technical solution, the bottom of the rotating shaft 6 is connected to the lower turntable 12, and the outer side wall of the lower turntable 12 is connected to the inner side wall of the shoe cap 2. The lower turntable 12 is provided with a third oblique hole 1201 and a fourth oblique hole 1202 in a radially outward manner to drive the lower turntable 12 to rotate. The third oblique hole 1201 and the fourth oblique hole 1202 are provided in multiples at equal intervals along the circumference of the rotating shaft 6. The third oblique hole 1201 and the fourth oblique hole 1202 are both tapered and gradually expand downward and can deflect the jet towards the side wall of the shoe cap 2. The flow rate of the third oblique hole 1201 is greater than that of the fourth oblique hole 1202.

[0064] In the above technical solution, the lower rotary table 12 is connected to the guide shoe cap 2. When the rotating shaft 6 rotates, the lower rotary table 12 and the guide shoe cap 2 can rotate synchronously with the rotating shaft 6, so that the cementing fluid can be sprayed out in a rotating manner to form a large vortex outside the pipe. It should be noted that when the lower rotary table 12 is connected to the guide shoe cap 2, the guide shoe cap 2 and the shell 1 do not need to be provided with a bearing. They can directly rotate and abut against each other. It is preferred to use a stepped groove to rotate and connect. The third inclined hole 1201 and the fourth inclined hole 1202 of the lower rotary table 12 are both tapered and gradually expand downwards. When the cementing fluid flows out from the third inclined hole 1201 and the fourth inclined hole 1202, a small vortex is generated, which further improves the uniformity of the cementing fluid. At the same time, the third inclined hole 1201 and the fourth inclined hole 1202 can deflect the jet towards the side wall of the guide shoe cap 2, impact the guide shoe cap 2 and form a vortex inside the pipe. The vortex inside the pipe and the vortex outside the pipe work together to further improve the cementing effect.

[0065] The working principle and process of this embodiment are as follows: In the initial state, the piston 8 in the piston cylinder 4 unseals the upper side hole 401 and seals the lower side hole 402, injecting cementing fluid into the housing 1. When the cementing fluid flows through the upper rotary table 7, it drives the upper rotary table 7 and the rotating shaft 6 connected to the upper rotary table 7 to rotate. A portion of the cementing fluid flows into the piston cylinder 4 from the first inclined hole 701, and then into the annulus 5 from the upper side hole 401. Another portion of the cementing fluid rotates into the annulus 5 from the second inclined hole 702. When the rotating shaft 6 rotates, it drives the piston 8 to rise and fall through the cam mechanism. When the piston 8 rises, it seals the upper side hole 401. The cementing fluid flowing into the annulus 5 from the upper side hole 401 decreases until it reaches zero. Simultaneously, the lower side hole 402 is unsealed, drawing some cementing fluid from the annulus 5 into the bottom of the piston cylinder 4. The cementing fluid in the annulus 5 flows through the mounting plate 3 at a low velocity. When the piston 8 descends, the upper side hole 401 is unsealed, increasing the cementing fluid flowing into the annulus 5. At the same time, the lower side hole 402 is sealed, injecting cementing fluid from the bottom of the piston cylinder 4 into the annulus 5. The cementing fluid in the annulus 5 flows through the mounting plate 3 at a high velocity. Therefore, as the piston 8 rises and falls, the flow velocity of the cementing fluid passing through the mounting plate 3 undergoes periodic high and low changes, forming... The cementing fluid passing through the mounting plate 3 is divided into two paths. One path passes through the swirl hole 301 of the mounting plate 3 and impacts the turbine 11 from top to bottom, driving the turbine 11 and the shaft 6 connected to the turbine 11 to rotate. The other path enters the flow channel 903 of the central rotary table 9 through the connecting hole 305 of the mounting plate 3, pushing the central rotary table 9 and the shaft 6 connected to the central rotary table 9 to rotate. The cementing fluid flowing out of the central rotary table 9 enters the cavity 602 of the shaft 6, and then enters the hollow blade 1102 of the turbine 11 from the cavity 602 and exits from the hollow blade 1102. The cementing fluid flows out from the bottom, driving the turbine 11 and the shaft connected to the turbine 11 to rotate from the inside. The two cementing fluids drive the turbine 11 from the outside and the inside respectively, further enhancing the rotation of the shaft 6. After passing through the turbine 11, the cementing fluid continues to flow downward. When it flows through the third inclined hole 1201 and the fourth inclined hole 1202 of the lower rotary table 12, it drives the lower rotary table 12, the shaft 6 connected to the lower rotary table 12, and the guide shoe cap 2 to rotate. A swirling flow is generated in the guide shoe cap 2. At the same time, it is rotated and ejected from the side injection hole 203 and the bottom injection hole 204 of the guide shoe cap 2, forming an external swirling flow, which greatly improves the cementing quality.

[0066] Example 2

[0067] Combined with appendix Figures 1 to 10 This embodiment provides a method for using a pulsed vortex cementing agitator, including the following steps:

[0068] Step S1: Connect the top of the casing 1 to the cementing string, and then lower it to the target position in the wellbore;

[0069] Step S2: Inject cementing fluid into the shell 1. When the cementing fluid flows through the upper rotary table 7, it drives the upper rotary table 7 and the rotating shaft 6 connected to the upper rotary table 7 to rotate. Part of the cementing fluid flows into the piston cylinder 4 from the first inclined hole 701, and then flows into the annulus 5 from the upper side hole 401 of the piston cylinder 4. Another part of the cementing fluid flows into the annulus 5 from the second inclined hole 702. The cementing fluid in the annulus 5 flows out from the swirling hole 301 inclined on the mounting plate 3, forming an in-pipe swirling flow.

[0070] In step S3, when the shaft 6 rotates, the piston 8 is driven to rise and fall through the cam mechanism. When the piston 8 rises, the cementing fluid flowing into the annulus 5 from the upper side hole 401 decreases until it reaches zero. The cementing fluid in the annulus 5 passes through the mounting plate 3 at a low flow rate. When the piston 8 falls, the upper side hole 401 is unsealed, and the cementing fluid flowing into the annulus 5 from the upper side hole 401 increases. The cementing fluid in the annulus 5 passes through the mounting plate 3 at a high flow rate. The piston 8 continues to rise and fall, and the flow rate of the cementing fluid passing through the mounting plate 3 produces periodic high and low changes, forming pulse oscillation. The swirling oscillation and counter-current in the tube can increase the density and uniformity of the cementing fluid distribution.

[0071] In step S4, the cementing fluid in the shell 1 enters the guide shoe cap 2 and is finally sprayed out from the guide shoe cap 2 in a rotating manner, forming an external vortex. The external vortex can more effectively carry the bottom mud cake and the loose mud cake on the well wall to the wellhead, improve the wellbore purification state, and thus improve the cementing quality.

[0072] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. A pulse vortex cementing agitator, comprising a housing (1), characterized in that, The bottom of the housing (1) is rotatably connected to the shoe cap (2). The housing (1) is provided with an installation plate (3). The top of the installation plate (3) is provided with a piston cylinder (4) with an upper opening and forming an annular space (5) with the housing (1). The installation plate (3) is provided with an inclined swirling hole (301) communicating with the annular space (5). The upper side hole (401) communicating with the annular space (5) is provided on the side wall of the piston cylinder (4). The bottom of the rotating shaft (6) rotates through the piston cylinder (4) and the installation plate (3). The top of the rotating shaft (6) is provided with a hydraulically driven rotating upper turntable (7). The upper turntable (7) is provided with a first inclined hole (701) communicating with the piston cylinder (4) and a second inclined hole (702) communicating with the annular space (5). The rotating shaft (6) is connected to the piston (8) through a cam mechanism. When the rotating shaft (6) rotates, the piston (8) rises and falls vertically along the piston cylinder (4) to block or unblock the upper side hole (401). The shoe cap (2) includes a connecting part (201) that is rotatably connected to the shell (1) and an eccentric ball head (202) whose center of gravity is off the axis. The eccentric ball head (202) has a plurality of downwardly inclined side spray holes (203) equidistantly arranged on the circumference of its side wall, and a bottom spray hole (204) is provided at the bottom of the eccentric ball head (202). The outer wall of the upper turntable (7) rotates and abuts against the housing (1), and the bottom of the upper turntable (7) rotates and abuts against the top of the piston cylinder (4). The first inclined hole (701) and the second inclined hole (702) are both provided at equal intervals around the circumference of the rotating shaft (6). The first inclined hole (701) and the second inclined hole (702) are both inclined along the circumference of the upper turntable (7). The flow rate of the first inclined hole (701) is greater than that of the second inclined hole (702). The cam mechanism includes an elliptical groove (601) on the outer wall of the rotating shaft (6) and inclined downwards, and a slider (805) on the inner wall of the piston (8) and slidingly engaged with the groove (601); the piston (8) includes a body (801) that can slide against the inner wall of the piston cylinder (4), a guide groove (802) is vertically provided on the outer wall of the body (801), a guide block (403) is provided on the inner wall of the piston cylinder (4) and slidingly engaged with the guide groove (802), a core groove (803) is provided at the top center of the body (801), two semi-circular cores (804) are provided in the core groove (803), a hemispherical slider (805) is provided on the inner wall of one core (804), and the core (804) is connected to the body (801) by screws (806).

2. The pulse vortex cementing agitator according to claim 1, characterized in that, The housing (1) includes a threaded upper shell (101) and a lower shell (102), the inner walls of the upper shell (101) and the lower shell (102) are joined to form an annular groove (103), and the side wall of the mounting plate (3) is provided with an annular flange (302) that can be inserted into the annular groove (103).

3. The pulse vortex cementing agitator according to claim 2, characterized in that, The piston cylinder (4) has a lower side hole (402) below the side wall. The upper side hole (401) and the lower side hole (402) are provided at equal intervals along the circumference of the piston cylinder (4). When the piston (8) rises and falls, it alternately blocks the upper side hole (401) and the lower side hole (402). The upper end face of the mounting plate (3) is provided with a centering groove (303) for mounting the piston cylinder (4).

4. The pulse vortex cementing agitator according to claim 3, characterized in that, The core (804) has an outwardly extending semi-circular insertion ring (807) at its top. The upper surface of one free end of the insertion ring (807) has a slot (808), and the upper surface of the other free end has a plug (809) corresponding to the slot (808). The slot (808) and the plug (809) have corresponding insertion holes (8010). The insertion ring (807), slot (808) and plug (809) on the two cores (804) can be inserted into a ring shape. The top of the body (801) has an insertion groove (8011) for accommodating the insertion ring (807). The insertion groove (8011) has a threaded groove (8012) corresponding to the insertion hole (8010). The screw (806) passes through the insertion hole (8010) and is screwed into the threaded groove (8012).

5. A pulsed vortex cementing agitator according to claim 4, characterized in that, The mounting plate (3) has a circular central groove (304) at its center. The central turntable (9) is mounted in the central groove (304) via a turntable bearing (10). The outer wall of the central turntable (9) has a first annular groove (901). The mounting plate (3) has a connecting hole (305) connecting the annular cavity (5) and the first annular groove (901). The inner wall of the central turntable (9) has a second annular groove (902). The inner circumference of the central turntable (9) has multiple flow channels (903) that connect the first annular groove (901) and the second annular groove (902) at equal intervals. The flow channels (903) are offset from the radial line of the central turntable (9). The rotating shaft (6) has a cavity (602) inside. The upper side wall of the cavity (602) has an upper through hole (603) that communicates with the second annular groove (902). The lower side wall of the cavity (602) has a lower through hole (604).

6. The pulse vortex cementing agitator according to claim 5, characterized in that, The rotating shaft (6) is provided with a turbine (11), which includes a central ring (1101) connected to the rotating shaft (6) and hollow blades (1102) equidistantly arranged around the circumference of the central ring (1101). The inner wall of the central ring (1101) is provided with a third annular groove (1103) that connects the cavity of the hollow blade (1102) and the lower through hole (604). The bottom of the hollow blade (1102) is provided with a liquid outlet hole (1104).

7. A pulsed vortex cementing agitator according to claim 6, characterized in that, The bottom of the rotating shaft (6) is connected to the lower turntable (12), and the outer side wall of the lower turntable (12) is connected to the inner side wall of the shoe cap (2). The lower turntable (12) is provided with a third inclined hole (1201) and a fourth inclined hole (1202) in a radial outward direction, which are hydraulically driven to rotate the lower turntable (12). The third inclined hole (1201) and the fourth inclined hole (1202) are provided in multiples at equal intervals along the circumference of the rotating shaft (6). The third inclined hole (1201) and the fourth inclined hole (1202) are both tapered and gradually expand downward and can be inclined to the side wall of the shoe cap (2) for jetting. The flow rate of the third inclined hole (1201) is greater than that of the fourth inclined hole (1202).

8. A method of using a pulsed vortex cementing agitator, characterized in that, Using the pulse vortex cementing agitator according to claim 1 includes the following steps: Step S1: Connect the top of the shell (1) to the cementing string, and then lower it to the target position in the wellbore; Step S2: Inject cementing fluid into the shell (1). When the cementing fluid flows through the upper rotary table (7), it drives the upper rotary table (7) and the rotating shaft (6) connected to the upper rotary table (7) to rotate. Part of the cementing fluid flows into the piston cylinder (4) from the first inclined hole (701) and then flows into the annulus (5) from the upper side hole (401) of the piston cylinder (4). Another part of the cementing fluid flows into the annulus (5) from the second inclined hole (702). The cementing fluid in the annulus (5) flows out from the swirling hole (301) set at an inclination on the mounting plate (3) to form an in-pipe swirling flow. Step S3: When the shaft (6) rotates, the piston (8) is driven to rise and fall through the cam mechanism. When the piston (8) rises, the cementing fluid flowing into the annulus (5) from the upper side hole (401) decreases until it is zero. The cementing fluid in the annulus (5) passes through the mounting plate (3) at a low flow rate. When the piston (8) falls, the upper side hole (401) is unsealed, and the cementing fluid flowing into the annulus (5) from the upper side hole (401) increases. The cementing fluid in the annulus (5) passes through the mounting plate (3) at a high flow rate. The piston (8) continues to rise and fall. The flow rate of the cementing fluid passing through the mounting plate (3) produces periodic high and low changes, forming pulse oscillation. The swirling oscillation and counter-current in the pipe can increase the density and uniformity of the cementing fluid distribution. Step S4: The cementing fluid in the shell (1) enters the guide shoe cap (2) and is finally sprayed out from the guide shoe cap (2) in a rotating manner, forming an external vortex. The external vortex can more effectively carry the bottom mud cake and the loose mud cake on the well wall to the wellhead, improve the wellbore purification state, and thus improve the cementing quality.

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