A drilling while flushing tool and a drilling while flushing method

Abstract

The application provides a drilling flushing tool and a drilling flushing method. The drilling flushing tool comprises an outer shell, an upper sliding sleeve, a lower sliding sleeve, a first locking mechanism, a second locking mechanism, a first pressure holding ball and a second pressure holding ball. A bypass hole is formed in the middle of the outer shell. A first sliding groove and a second sliding groove are formed in the inner part of the outer shell. The upper sliding sleeve is slidingly installed in the first sliding groove. The lower sliding sleeve is slidingly installed in the second sliding groove. Water eye mechanisms are formed in the upper sliding sleeve and the lower sliding sleeve. The bypass hole is connected with the second sliding groove. The upper sliding sleeve is connected with the outer shell through the first locking mechanism. The lower sliding sleeve is connected with the outer shell through the second locking mechanism. The first pressure holding ball is rollingly installed in the upper sliding sleeve. The second pressure holding ball is rollingly installed in the lower sliding sleeve.

Description

Technical Field

[0001] This invention relates to the field of drilling flushing technology, and more particularly to a flushing tool and a flushing method while drilling. Background Technology

[0002] During drilling, after cementing the production casing, a cement plug is drilled to the designed well depth. A wellbore cleaning string is simultaneously connected when the plug string is run. In the transition from drilling to completion, wellbore cleaning and fluid displacement have a significant impact on completion quality, production efficiency, and well profitability. Wellbore impurities can damage the formation and cause blockages, leading to numerous completion failures and costly remediation efforts. Running wellbore cleaning operations simultaneously reduces the number of operations and saves drilling time, facilitating a smooth transition from drilling to completion.

[0003] Currently, existing drilling duct flushing tools cannot freely switch between the water jet and the annulus flow channel, increasing the time required for wellbore cleaning and leading to a decrease in overall drilling efficiency. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a drilling flushing tool and a drilling flushing method to address the shortcomings of the prior art.

[0005] The technical solution of the present invention to solve the above-mentioned technical problems is as follows: A drilling flushing tool includes: an outer shell, an upper sliding sleeve, a lower sliding sleeve, a first locking mechanism, a second locking mechanism, a first pressure ball, and a second pressure ball. A bypass hole is provided in the middle of the outer shell, and a first sliding groove and a second sliding groove are provided inside the outer shell. The upper sliding sleeve is slidably installed in the first sliding groove, and the lower sliding sleeve is slidably installed in the second sliding groove. Water eye mechanisms are provided on both the upper sliding sleeve and the lower sliding sleeve. The bypass hole is connected to the second sliding groove. The upper sliding sleeve is connected to the outer shell through the first locking mechanism, and the lower sliding sleeve is connected to the outer shell through the second locking mechanism. The first pressure ball is rolled in the upper sliding sleeve, and the second pressure ball is rolled in the lower sliding sleeve.

[0006] The beneficial effects of adopting the technical solution of this invention are as follows: By inserting the second pressure-reducing ball, the sliding sleeve is pressurized. Under the action of water pressure, the sliding sleeve is released from the restraint of the second locking mechanism, allowing the sliding sleeve to slide, thereby opening the bypass hole and water eye mechanism, thus opening the circulation channel and increasing the annular return speed; then, the first pressure-reducing ball is inserted to pressurize the upper sliding sleeve. Under the action of water pressure, the upper sliding sleeve is released from the restraint of the first locking mechanism, allowing the upper sliding sleeve to slide, thereby closing the circulation channel. This can change the liquid flow path inside the outer shell, and after the flow channel switches to the annulus, the drilling fluid can efficiently flush the well wall, realizing the switching between the water eye and the annulus flow channel, shortening the cleaning time, improving the flushing effect and working efficiency.

[0007] Furthermore, a first cavity is formed in the middle of the first slide groove, and a second cavity is formed in the middle of the second slide groove. The water eye mechanism includes: a first water eye for connecting to the first cavity, a second water eye for connecting to the second cavity, and a third water eye for connecting to the second cavity. The first water eye is located on the top side wall of the upper slide sleeve, the second water eye is located on the bottom side wall of the upper slide sleeve, and the third water eye is located on the top side wall of the lower slide sleeve.

[0008] The beneficial effects of adopting the above-mentioned further technical solution are: the setting of the cavity and water eye facilitates the formation of a circulation channel, facilitates the connection between the water eye mechanism on the upper sliding sleeve and the water eye mechanism on the lower sliding sleeve, thereby changing the liquid flow path inside the outer shell, realizing the switching between water eye and annular flow channel, shortening the cleaning time, improving the rinsing effect and work efficiency.

[0009] Furthermore, both the first locking mechanism and the second locking mechanism are shear pins. The outer shell has an outer pin hole for installing the shear pin, and the upper sliding sleeve and the lower sliding sleeve both have an inner pin hole for installing the shear pin. The two ends of the shear pin are installed one-to-one in the outer pin hole and the inner pin hole.

[0010] The beneficial effects of adopting the above-mentioned further technical solution are as follows: the setting of the shear pin facilitates the locking of the relative position of the sliding sleeve and the outer shell, facilitates the installation and maintenance of the locking mechanism, reduces costs, and simplifies the structure. By inserting the second pressure-locking ball, the sliding sleeve is pressurized, and under the action of water pressure, the sliding sleeve is freed from the restraint of the shear pin, allowing the sliding sleeve to slide, thereby opening the bypass hole and water eye mechanism, thus opening the circulation channel; then, the first pressure-locking ball is inserted to pressurize the upper sliding sleeve, and under the action of water pressure, the upper sliding sleeve is freed from the restraint of the shear pin, allowing the upper sliding sleeve to slide, thereby closing the circulation channel. This can change the liquid flow path inside the outer shell, and after the flow channel switches to the annulus, the drilling fluid can efficiently flush the well wall, realize the switching between the water eye and the annulus flow channel, shorten the cleaning time, and improve the flushing effect and work efficiency.

[0011] Furthermore, the first pressure ball abuts against the middle of the upper sliding sleeve, the second pressure ball abuts against the bottom of the lower sliding sleeve, the lower sliding sleeve abuts against the bottom of the outer shell, and the top of the outer shell is a stepped cavity.

[0012] The beneficial effects of adopting the above-mentioned further technical solution are as follows: The upper and lower sliding sleeves with different inner diameters facilitate the engagement of the pressure-locking ball at different positions under water pressure, thereby altering the liquid flow path inside the outer shell. After switching the flow channel to the annulus, the drilling fluid can efficiently flush the well wall, achieving the switching between the waterhole and annulus flow channels, shortening cleaning time, and improving flushing effect and work efficiency. The stepped design of the outer shell's inner diameter further enhances the liquid's squeezing pressure, achieving more efficient flushing.

[0013] Furthermore, the upper sliding sleeve is located above the lower sliding sleeve, and the first sliding groove is connected to the second sliding groove.

[0014] The beneficial effects of adopting the above-mentioned further technical solutions are: it facilitates the installation and maintenance of the sliding sleeve, facilitates liquid flow, changes the liquid flow path inside the outer shell, and after the flow channel is switched to the annulus, it enables the drilling fluid to efficiently flush the well wall, realizes the switching between the water eye and the annulus flow channel, shortens the cleaning time, and improves the flushing effect and work efficiency.

[0015] Furthermore, the outer shell, the upper sliding sleeve, and the lower sliding sleeve are all tubular structures, and the outer diameters of the upper sliding sleeve and the lower sliding sleeve are the same.

[0016] The beneficial effects of adopting the above-mentioned further technical solutions are: it facilitates the installation and maintenance of the sliding sleeve, facilitates liquid flow, changes the liquid flow path inside the outer shell, and after the flow channel is switched to the annulus, it enables the drilling fluid to efficiently flush the well wall, realizes the switching between the water eye and the annulus flow channel, shortens the cleaning time, and improves the flushing effect and work efficiency.

[0017] Furthermore, the upper sliding sleeve is located on the rolling trajectory of the second pressure ball, and the bypass hole is located on the sliding trajectory of the lower sliding sleeve.

[0018] The beneficial effects of adopting the above-mentioned further technical solution are as follows: The upper sliding sleeve is located on the rolling trajectory of the second pressure-retaining ball, which facilitates the removal and placement of the second pressure-retaining ball from the top of the outer casing, improving switching efficiency and user experience. The bypass hole is located on the sliding trajectory of the lower sliding sleeve, which facilitates the lower sliding sleeve to block and open the bypass hole, thereby changing the liquid flow path inside the outer casing. After the flow channel switches to the annulus, the drilling fluid can efficiently flush the well wall, realizing the switching between the water eye and the annulus flow channel, shortening the cleaning time, and improving the flushing effect and work efficiency.

[0019] Furthermore, both the upper sliding sleeve and the lower sliding sleeve are integrally formed structures, and sealing sleeves are respectively installed on the outer side walls of the upper sliding sleeve and the lower sliding sleeve, with the free end of the sealing sleeve abutting against the outer shell.

[0020] The beneficial effects of adopting the above-mentioned further technical solutions are: the setting of the sealing sleeve improves the sealing effect between the upper and lower sliding sleeves and the inner wall of the outer shell, and the upper and lower sliding sleeves, which are made by one-piece molding process, have no joints in the middle, have high tensile and torsional strength, and improve the durability of the drilling flushing tool.

[0021] Furthermore, anti-slip grooves for installing the sealing sleeve are respectively provided on the outer side walls of the upper sliding sleeve and the lower sliding sleeve. The sealing sleeve is installed in the anti-slip groove, and the sealing sleeve is made of fluororubber.

[0022] The beneficial effects of adopting the above-mentioned further technical solutions are: the anti-slip groove prevents the sealing sleeve from shaking, facilitates the installation and maintenance of the sealing sleeve, reduces costs, improves the sealing effect between the upper and lower sliding sleeves and the inner wall of the outer casing, and improves the stability and reliability of the drilling flushing tool.

[0023] Furthermore, the present invention also provides a drilling flushing method, based on a drilling flushing tool described in any one of the above claims, the drilling flushing method comprising:

[0024] In the first state, the liquid flows from the top of the outer shell through the upper and lower sliding sleeves and is discharged at the bottom of the outer shell.

[0025] In the second state, the second pressure ball is placed on the top of the outer shell. Under the action of water flow, the second pressure ball abuts against the bottom of the sliding sleeve and seals the bottom of the sliding sleeve. The sliding sleeve disengages from the second locking mechanism and slides down. The bypass hole is connected to the water eye mechanism on the sliding sleeve.

[0026] In the third state, the first pressure ball is placed on the top of the outer shell. Under the action of water flow, the first pressure ball abuts against the middle of the upper sliding sleeve and blocks the bottom of the upper sliding sleeve. The upper sliding sleeve disengages from the first locking mechanism, slides down, and abuts against the top of the lower sliding sleeve. The lower sliding sleeve blocks the bypass hole.

[0027] The beneficial effects of adopting the technical solution of this invention are as follows: By inserting the second pressure-reducing ball, the sliding sleeve is pressurized. Under the action of water pressure, the sliding sleeve is released from the restraint of the second locking mechanism, allowing the sliding sleeve to slide, thereby opening the bypass hole and water eye mechanism, thus opening the circulation channel and increasing the annular return speed; then, the first pressure-reducing ball is inserted to pressurize the upper sliding sleeve. Under the action of water pressure, the upper sliding sleeve is released from the restraint of the first locking mechanism, allowing the upper sliding sleeve to slide, thereby closing the circulation channel. This can change the liquid flow path inside the outer shell, and after the flow channel switches to the annulus, the drilling fluid can efficiently flush the well wall, realizing the switching between the water eye and the annulus flow channel, shortening the cleaning time, improving the flushing effect and working efficiency.

[0028] The advantages of additional aspects of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0029] Figure 1 This is one of the structural schematic diagrams of the rinsing tool provided in an embodiment of the present invention.

[0030] Figure 2 This is a second schematic diagram of the rinsing tool provided in an embodiment of the present invention.

[0031] Figure 3 The third schematic diagram of the rinsing tool provided in the embodiment of the present invention.

[0032] Figure 4 The fourth schematic diagram of the rinsing tool provided in the embodiment of the present invention.

[0033] Figure 5 The fifth schematic diagram of the rinsing tool provided in the embodiment of the present invention.

[0034] Figure 6 This is the sixth schematic diagram of the rinsing tool provided in the embodiment of the present invention.

[0035] Figure 7 This is a schematic flowchart illustrating the rinsing method provided in an embodiment of the present invention.

[0036] Explanation of reference numerals in the attached drawings: 1. Outer shell; 2. Bypass hole; 3. First slide groove; 31. First cavity; 4. Second slide groove; 41. Second cavity; 5. Outer nail hole; 51. First locking mechanism; 52. Inner nail hole; 53. Second locking mechanism; 6. Flushing assembly; 61. Upper sliding sleeve; 611. First water eye; 612. Second water eye; 62. Lower sliding sleeve; 621. Third water eye; 63. First pressure ball; 64. Second pressure ball; 65. Sealing sleeve; 66. Water eye mechanism. Detailed Implementation

[0037] The principles and features of the present invention are described below with reference to the accompanying drawings. The examples given are only for explaining the present invention and are not intended to limit the scope of the present invention.

[0038] like Figures 1 to 6 As shown, this embodiment of the invention provides a drilling flushing tool, including: a housing 1, an upper sliding sleeve 61, a lower sliding sleeve 62, a first locking mechanism 51, a second locking mechanism 53, a first pressure ball 63, and a second pressure ball 64. A bypass hole 2 is provided in the middle of the housing 1. A first sliding groove 3 and a second sliding groove 4 are provided inside the housing 1. The upper sliding sleeve 61 is slidably installed in the first sliding groove 3, and the lower sliding sleeve 62 is slidably installed in the second sliding groove 4. Water eye mechanisms 66 are provided on both the upper sliding sleeve 61 and the lower sliding sleeve 62. The bypass hole 2 is connected to the second sliding groove 4. The upper sliding sleeve 61 is connected to the housing 1 via the first locking mechanism 51, and the lower sliding sleeve 62 is connected to the housing 1 via the second locking mechanism 53. The first pressure ball 63 is rotatably installed in the upper sliding sleeve 61, and the second pressure ball 64 is rotatably installed in the lower sliding sleeve 62.

[0039] The beneficial effects of adopting the technical solution of this invention are as follows: By inserting the second pressure-reducing ball, the sliding sleeve is pressurized. Under the action of water pressure, the sliding sleeve is released from the restraint of the second locking mechanism, allowing the sliding sleeve to slide, thereby opening the bypass hole and water eye mechanism, thus opening the circulation channel and increasing the annular return speed; then, the first pressure-reducing ball is inserted to pressurize the upper sliding sleeve. Under the action of water pressure, the upper sliding sleeve is released from the restraint of the first locking mechanism, allowing the upper sliding sleeve to slide, thereby closing the circulation channel. This can change the liquid flow path inside the outer shell, and after the flow channel switches to the annulus, the drilling fluid can efficiently flush the well wall, realizing the switching between the water eye and the annulus flow channel, shortening the cleaning time, improving the flushing effect and working efficiency.

[0040] The number of bypass holes 2 can be multiple, and multiple bypass holes 2 are arranged around the peripheral sidewall of the outer casing.

[0041] This invention provides a drilling flushing tool, relating to the field of drilling, belonging to the category of downhole valves and wellbore cleaning tools. It is primarily used, but not limited to, for cleaning the wellbore during drilling, switching flow channels between the water inlet and annulus in the downhole tool string, and distributing flow. This drilling flushing tool was designed to address the shortcomings of existing technologies that make it difficult to freely switch between the water inlet and annulus flow channels. The drilling flushing tool includes an outer shell with a bypass hole in the middle of its side wall, which communicates with the inner cavity of the outer shell. The upper and lower sides of the inner wall of the outer shell are respectively provided with a first groove and a second groove. A first cavity is formed in the middle of the inner wall of the first groove. By inserting a second pressure ball, pressure is applied to the lower sliding sleeve, ultimately breaking the shear pin and causing the lower sliding sleeve to slide, thereby opening the bypass hole and the water inlet (water inlet mechanism), thus opening the circulation channel. Then, the first pressure ball is inserted to apply pressure to the upper sliding sleeve, ultimately breaking the shear pin (locking mechanism), causing the upper sliding sleeve to slide, thus closing the circulation channel. It can change the liquid flow path inside the shell and, after the flow channel is switched to the annulus, enable the drilling fluid to efficiently flush the well wall, thereby improving the flushing effect of the drilling flushing tool.

[0042] like Figures 1 to 6 As shown, the first slide groove 3 has a first cavity 31 in the middle, and the second slide groove 4 has a second cavity 41 in the middle. The water eye mechanism 66 includes: a first water eye 611 for connecting to the first cavity 31, a second water eye 612 for connecting to the second cavity 41, and a third water eye 621 for connecting to the second cavity 41. The first water eye 611 is located on the top side wall of the upper slide sleeve 61, the second water eye 612 is located on the bottom side wall of the upper slide sleeve 61, and the third water eye 621 is located on the top side wall of the lower slide sleeve 62.

[0043] The beneficial effects of adopting the above-mentioned further technical solution are: the setting of the cavity and water eye facilitates the formation of a circulation channel, facilitates the connection between the water eye mechanism on the upper sliding sleeve and the water eye mechanism on the lower sliding sleeve, thereby changing the liquid flow path inside the outer shell, realizing the switching between water eye and annular flow channel, shortening the cleaning time, improving the rinsing effect and work efficiency.

[0044] The water eye mechanism is connected to the internal cavity of the chute.

[0045] like Figures 1 to 6 As shown, the first locking mechanism 51 and the second locking mechanism 53 are both scissor pins. The outer shell 1 is provided with an outer pin hole 5 for installing scissor pins, and the upper sliding sleeve 61 and the lower sliding sleeve 62 are both provided with inner pin holes 52 for installing scissor pins. The two ends of the scissor pin are installed one-to-one in the outer pin hole 5 and the inner pin hole 52.

[0046] The beneficial effects of adopting the above-mentioned further technical solution are as follows: the setting of the shear pin facilitates the locking of the relative position of the sliding sleeve and the outer shell, facilitates the installation and maintenance of the locking mechanism, reduces costs, and simplifies the structure. By inserting the second pressure-locking ball, the sliding sleeve is pressurized, and under the action of water pressure, the sliding sleeve is freed from the restraint of the shear pin, allowing the sliding sleeve to slide, thereby opening the bypass hole and water eye mechanism, thus opening the circulation channel; then, the first pressure-locking ball is inserted to pressurize the upper sliding sleeve, and under the action of water pressure, the upper sliding sleeve is freed from the restraint of the shear pin, allowing the upper sliding sleeve to slide, thereby closing the circulation channel. This can change the liquid flow path inside the outer shell, and after the flow channel switches to the annulus, the drilling fluid can efficiently flush the well wall, realize the switching between the water eye and the annulus flow channel, shorten the cleaning time, and improve the flushing effect and work efficiency.

[0047] like Figures 1 to 6 As shown, further, the first pressure ball 63 abuts against the middle of the upper sliding sleeve 61, the second pressure ball 64 abuts against the bottom of the lower sliding sleeve 62, the lower sliding sleeve 62 abuts against the bottom of the outer shell 1, and the top of the outer shell 1 is a stepped cavity.

[0048] The beneficial effects of adopting the above-mentioned further technical solution are as follows: The upper and lower sliding sleeves with different inner diameters facilitate the engagement of the pressure-locking ball at different positions under water pressure, thereby altering the liquid flow path inside the outer shell. After switching the flow channel to the annulus, the drilling fluid can efficiently flush the well wall, achieving the switching between the waterhole and annulus flow channels, shortening cleaning time, and improving flushing effect and work efficiency. The stepped design of the outer shell's inner diameter further enhances the liquid's squeezing pressure, achieving more efficient flushing.

[0049] like Figures 1 to 6 As shown, the upper sliding sleeve 61 is located above the lower sliding sleeve 62, and the first sliding groove 3 is connected to the second sliding groove 4.

[0050] The beneficial effects of adopting the above-mentioned further technical solutions are: it facilitates the installation and maintenance of the sliding sleeve, facilitates liquid flow, changes the liquid flow path inside the outer shell, and after the flow channel is switched to the annulus, it enables the drilling fluid to efficiently flush the well wall, realizes the switching between the water eye and the annulus flow channel, shortens the cleaning time, and improves the flushing effect and work efficiency.

[0051] like Figures 1 to 6 As shown, further, the outer shell 1, the upper sliding sleeve 61 and the lower sliding sleeve 62 are all tubular structures, and the outer diameters of the upper sliding sleeve 61 and the lower sliding sleeve 62 are the same.

[0052] The beneficial effects of adopting the above-mentioned further technical solutions are: it facilitates the installation and maintenance of the sliding sleeve, facilitates liquid flow, changes the liquid flow path inside the outer shell, and after the flow channel is switched to the annulus, it enables the drilling fluid to efficiently flush the well wall, realizes the switching between the water eye and the annulus flow channel, shortens the cleaning time, and improves the flushing effect and work efficiency.

[0053] like Figures 1 to 6 As shown, the upper sliding sleeve 62 is located on the rolling trajectory of the second pressure ball 64, and the bypass hole 2 is located on the sliding trajectory of the lower sliding sleeve 62.

[0054] The beneficial effects of adopting the above-mentioned further technical solution are as follows: The upper sliding sleeve is located on the rolling trajectory of the second pressure-retaining ball, which facilitates the removal and placement of the second pressure-retaining ball from the top of the outer casing, improving switching efficiency and user experience. The bypass hole is located on the sliding trajectory of the lower sliding sleeve, which facilitates the lower sliding sleeve to block and open the bypass hole, thereby changing the liquid flow path inside the outer casing. After the flow channel switches to the annulus, the drilling fluid can efficiently flush the well wall, realizing the switching between the water eye and the annulus flow channel, shortening the cleaning time, and improving the flushing effect and work efficiency.

[0055] like Figures 1 to 6 As shown, the upper sliding sleeve 61 and the lower sliding sleeve 62 are both integrally formed structures. Sealing sleeves 65 are respectively installed on the outer side walls of the upper sliding sleeve 61 and the lower sliding sleeve 62, and the free end of the sealing sleeve 65 abuts against the outer shell 1.

[0056] The beneficial effects of adopting the above-mentioned further technical solutions are: the setting of the sealing sleeve improves the sealing effect between the upper and lower sliding sleeves and the inner wall of the outer shell, and the upper and lower sliding sleeves, which are made by one-piece molding process, have no joints in the middle, have high tensile and torsional strength, and improve the durability of the drilling flushing tool.

[0057] like Figures 1 to 6 As shown, further, the outer side walls of the upper sliding sleeve 61 and the lower sliding sleeve 62 are respectively provided with anti-slip grooves for installing the sealing sleeve 65. The sealing sleeve 65 is installed in the anti-slip grooves, and the sealing sleeve 65 is made of fluororubber.

[0058] The beneficial effects of adopting the above-mentioned further technical solutions are: the anti-slip groove prevents the sealing sleeve from shaking, facilitates the installation and maintenance of the sealing sleeve, reduces costs, improves the sealing effect between the upper and lower sliding sleeves and the inner wall of the outer casing, and improves the stability and reliability of the drilling flushing tool.

[0059] The drilling flushing tool is a large-diameter circulating flushing tool for drilling, including: a housing 1, a bypass hole 2 in the middle of the side wall of the housing 1, and the bypass hole 2 is connected to the inner cavity of the housing 1; a first groove 3 and a second groove 4 are respectively provided on the upper and lower sides of the inner wall of the housing 1; a first cavity 31 is provided in the middle of the inner wall of the first groove 3; a second cavity 41 is provided in the middle of the inner wall of the second groove 4; and an outer nail hole 5 is provided in the annular shape on the side wall of the housing 1 at the first groove 3 and the second groove 4, with a shear nail 51 threaded inside the outer nail hole 5.

[0060] The flushing assembly 6 is slidably connected to the inner walls of the first chute 3 and the second chute 4. The flushing assembly 6 is used to complete the large-diameter circulating flushing.

[0061] Reference Figures 2 to 6 The flushing assembly 6 includes an upper sliding sleeve 61 and a lower sliding sleeve 62. The upper sliding sleeve 61 is slidably connected to the inner wall of the first sliding groove 3, and the lower sliding sleeve 62 is slidably connected to the inner wall of the second sliding groove 4. The side wall of the lower sliding sleeve 62 is fitted with the bypass hole 2. Both the upper sliding sleeve 61 and the lower sliding sleeve 62 have inner nail holes 52 on their side walls. The inner nail holes 52 are aligned with the outer nail holes 5, and the inner nail holes 52 are threadedly connected to the shear nails 51. The outer diameters of the upper sliding sleeve 61 and the lower sliding sleeve 62 are the same.

[0062] Reference Figure 5 and Figure 6 The upper sliding sleeve 61 has a first water eye 611 and a second water eye 612 at both ends, and the lower sliding sleeve 62 has a third water eye 621 on the upper part of its side wall. The first water eye 611 can be connected to the first cavity 31, and the second water eye 612 and the third water eye 621 can be connected to the second cavity 41. The inner diameter of the upper sliding sleeve 61 is larger than the inner diameter of the lower sliding sleeve 62. The inner diameter of the upper sliding sleeve 61 is larger at both ends than in the middle, and the upper diameter of the lower sliding sleeve 62 is larger than the lower diameter.

[0063] Reference Figure 6 The upper sliding sleeve 61 is slidably connected to a first pressure ball 63, and the outer diameter of the first pressure ball 63 is larger than the inner diameter of the middle part of the upper sliding sleeve 61. The lower sliding sleeve 62 is slidably connected to a second pressure ball 64, and the outer diameter of the second pressure ball 64 is larger than the inner diameter of the lower end of the lower sliding sleeve 62. The outer diameter of the first pressure ball 63 is larger than the outer diameter of the second pressure ball 64.

[0064] The upper sliding sleeve 61 and the lower sliding sleeve 62 are provided with multiple anti-slip grooves on their side walls, and a sealing sleeve 65 is fixedly connected in each of the multiple anti-slip grooves. The sealing sleeve 65 is made of fluororubber, and the upper sliding sleeve 61 and the lower sliding sleeve 62 are both made by an integral molding process.

[0065] The above structure improves the sealing effect between the upper sliding sleeve 61 and the lower sliding sleeve 62 and the inner wall of the outer shell 1. The upper sliding sleeve 61 and the lower sliding sleeve 62, which are made by one-piece molding process, have no joints in the middle and have high tensile and torsional strength, thereby improving the durability of the drilling flushing tool.

[0066] The upper inner diameter of the outer shell 1 is stepped, and the upper inner diameter of the outer shell 1 is larger than the lower inner diameter, while the lower inner diameter of the outer shell 1 is smaller than the outer diameter of the sliding sleeve 62.

[0067] With the above structure, the upper sliding sleeve 61 and the lower sliding sleeve 62 can be effectively fixed to the outer shell 1, thereby enabling the circulating flushing operation to proceed smoothly and improving the practicality of the drilling flushing tool. Furthermore, the stepped inner diameter of the outer shell 1 can further increase the pressure of the liquid, thereby achieving more efficient flushing.

[0068] First, by inserting the second pressure-pressurizing ball, the sliding sleeve is pressurized, eventually breaking the shear pin (locking mechanism) and causing the sliding sleeve to slide. This opens the bypass hole and water eye (water eye mechanism), thereby opening the circulation channel and enabling jet flushing of the inner wall of the outer casing's outer pipe, while also increasing the annular return velocity. Then, the first pressure-pressurizing ball is inserted, pressurizing the upper sliding sleeve and eventually breaking the shear pin, causing the upper sliding sleeve to slide and closing the circulation channel. In summary, this changes the fluid flow path inside the outer casing, and after the flow channel switches to the annulus, the drilling fluid can efficiently flush the well wall, thereby improving the flushing effect of the drilling flushing tool.

[0069] like Figure 7 As shown, in addition, the present invention also provides a drilling flushing method, based on a drilling flushing tool described in any one of the above claims, the drilling flushing method comprising:

[0070] S1. In the first state, the liquid flows from the top of the outer shell through the upper and lower sliding sleeves and is discharged at the bottom of the outer shell.

[0071] S2, in the second state, the second pressure ball is placed on the top of the outer shell. Under the action of water flow, the second pressure ball abuts against the bottom of the sliding sleeve and seals the bottom of the sliding sleeve. The sliding sleeve disengages from the second locking mechanism and slides down. The bypass hole is connected to the water eye mechanism on the sliding sleeve.

[0072] S3, in the third state, the first pressure ball is placed on the top of the outer shell. Under the action of water flow, the first pressure ball abuts against the middle of the upper sliding sleeve and blocks the bottom of the upper sliding sleeve. The upper sliding sleeve disengages from the first locking mechanism, slides down and abuts against the top of the lower sliding sleeve, and the lower sliding sleeve blocks the bypass hole.

[0073] The beneficial effects of adopting the technical solution of this invention are as follows: By inserting the second pressure-reducing ball, the sliding sleeve is pressurized. Under the action of water pressure, the sliding sleeve is released from the restraint of the second locking mechanism, allowing the sliding sleeve to slide, thereby opening the bypass hole and water eye mechanism, thus opening the circulation channel and increasing the annular return speed; then, the first pressure-reducing ball is inserted to pressurize the upper sliding sleeve. Under the action of water pressure, the upper sliding sleeve is released from the restraint of the first locking mechanism, allowing the upper sliding sleeve to slide, thereby closing the circulation channel. This can change the liquid flow path inside the outer shell, and after the flow channel switches to the annulus, the drilling fluid can efficiently flush the well wall, realizing the switching between the water eye and the annulus flow channel, shortening the cleaning time, improving the flushing effect and working efficiency.

[0074] In the normal state (first state), the liquid inside the outer casing 1 flows through the upper sliding sleeve 61 and the lower sliding sleeve 62 and is then discharged.

[0075] When rinsing is required (second state), the second pressure-holding ball 64 is first placed inside the outer shell 1. With the flow of water, the second pressure-holding ball 64 will enter the lower sleeve 62. Since the outer diameter of the second pressure-holding ball 64 is larger than the inner diameter of the lower end of the lower sleeve 62, the second pressure-holding ball 64 will block the lower sleeve 62. Under the effect of continuous liquid flow, the water will gather energy at the upper end of the lower sleeve 62 to achieve pressure holding. Finally, when the accumulated sliding force of pressure holding is greater than the breaking force of the shear pin (second locking mechanism), the shear pin (second locking mechanism) fixed on the side wall of the lower sleeve 62 will be sheared, thereby causing the lower sleeve 62 to move towards the lower end of the outer shell 1. This will cause the lower sleeve 62 to disengage from the bypass hole 2, thereby connecting the inner cavity of the outer shell 1 with the bypass hole 2. The third water eye 621 will then connect with the second cavity 41, thus completing the switching of the flow channel. At this time, the flow direction of the liquid inside the outer shell 1 is two-way. One part flows from the inside of the outer shell 1 through the bypass hole 2 and moves towards the inlet end of the outer shell 1. The other part flows from the inside of the outer shell 1 through the upper sliding sleeve 61, enters the second cavity 41, and then enters the lower sliding sleeve 62 through the third water hole 621, and finally exits the outer shell 1, thereby triggering the circulating flushing mode of the drilling flushing tool, thereby improving the flushing efficiency of the drilling flushing tool.

[0076] In the third state, based on the second state, the first pressure-locking ball 63 is placed inside the outer shell 1. With the flow of water, the first pressure-locking ball 63 will engage with the upper end of the upper sliding sleeve 61. Because the outer diameter of the first pressure-locking ball 63 is larger than the inner diameter of the middle part of the upper sliding sleeve 61, it will seal the inner cavity of the upper sliding sleeve 61. At this time, under the effect of continuous liquid flow, pressure will be accumulated in the upper part of the upper sliding sleeve 61. When the accumulated sliding force exceeds the breaking force of the shear pin (first locking mechanism), it will shear the shear pin (first locking mechanism) fixed to the side wall of the upper sliding sleeve 61, thereby causing the upper sliding sleeve 61 to slide downwards to the lower sliding sleeve 62. The liquid moves in the direction of the upper sliding sleeve 61 and eventually fits tightly with the lower sliding sleeve 62. The lower sliding sleeve 62 will block the bypass hole 2. At this time, the first water eye 611 will be connected to the first cavity 31, and the second water eye 612 will be connected to the second cavity 41. At this time, the third water eye 621 is also connected to the second cavity 41. Thus, the liquid inside the outer shell 1 first enters the first cavity 31, then enters the upper sliding sleeve 61 through the first water eye 611, then flows through the upper sliding sleeve 61 into the second cavity 41 through the second water eye 612, and then enters the lower sliding sleeve 62 through the third water eye 621, and is then discharged from the outer shell 1.

[0077] In summary, by designing the structure to switch between different water channels and annular flow channels, and by deploying the first pressure-blocking ball 63 and the second pressure-blocking ball 64 respectively, the liquid flow path inside the outer casing 1 is changed. After the flow channel is switched to the annulus, the drilling fluid can efficiently flush the well wall, thereby improving the flushing effect of the drilling flushing tool.

[0078] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A drilling flushing tool, characterized in that, include: The device comprises an outer shell, an upper sliding sleeve, a lower sliding sleeve, a first locking mechanism, a second locking mechanism, a first pressure ball, and a second pressure ball. A bypass hole is provided in the middle of the outer shell. A first sliding groove and a second sliding groove are provided inside the outer shell. The upper sliding sleeve is slidably installed in the first sliding groove, and the lower sliding sleeve is slidably installed in the second sliding groove. Water eye mechanisms are provided on both the upper and lower sliding sleeves. The bypass hole is connected to the second sliding groove. The upper sliding sleeve is connected to the outer shell via the first locking mechanism, and the lower sliding sleeve is connected to the outer shell via the second locking mechanism. The first pressure ball is rotatably installed in the upper sliding sleeve, and the second pressure ball is rotatably installed in the lower sliding sleeve. The first slide groove has a first cavity in the middle, and the second slide groove has a second cavity in the middle. The water eye mechanism includes: a first water eye for connecting to the first cavity, a second water eye for connecting to the second cavity, and a third water eye for connecting to the second cavity. The first water eye is located on the top side wall of the upper slide sleeve, the second water eye is located on the bottom side wall of the upper slide sleeve, and the third water eye is located on the top side wall of the lower slide sleeve.

2. The drilling flushing tool according to claim 1, characterized in that, Both the first locking mechanism and the second locking mechanism are shear pins. The outer shell has an outer pin hole for installing the shear pin, and the upper sliding sleeve and the lower sliding sleeve both have an inner pin hole for installing the shear pin. The two ends of the shear pin are installed in the outer pin hole and the inner pin hole respectively.

3. The drilling flushing tool according to claim 1, characterized in that, The first pressure ball abuts against the middle of the upper sliding sleeve, the second pressure ball abuts against the bottom of the lower sliding sleeve, the lower sliding sleeve abuts against the bottom of the outer shell, and the top of the outer shell is a stepped cavity.

4. The drilling flushing tool according to claim 1, characterized in that, The upper sliding sleeve is located above the lower sliding sleeve, and the first sliding groove is connected to the second sliding groove.

5. A drilling flushing tool according to claim 1, characterized in that, The outer shell, the upper sliding sleeve, and the lower sliding sleeve are all tubular structures, and the outer diameters of the upper sliding sleeve and the lower sliding sleeve are the same.

6. A drilling flushing tool according to claim 1, characterized in that, The upper sliding sleeve is located on the rolling trajectory of the second pressure ball, and the bypass hole is located on the sliding trajectory of the lower sliding sleeve.

7. A drilling flushing tool according to claim 1, characterized in that, Both the upper sliding sleeve and the lower sliding sleeve are integrally formed structures. Sealing sleeves are respectively installed on the outer side walls of the upper sliding sleeve and the lower sliding sleeve, and the free end of the sealing sleeve abuts against the outer shell.

8. A drilling flushing tool according to claim 7, characterized in that, The outer walls of the upper sliding sleeve and the lower sliding sleeve are respectively provided with anti-slip grooves for installing the sealing sleeve. The sealing sleeve is installed in the anti-slip groove. The sealing sleeve is made of fluororubber.

9. A method for flushing while drilling, characterized in that, Based on any one of claims 1 to 8, a drilling flushing method includes: In the first state, the liquid flows from the top of the outer shell through the upper and lower sliding sleeves and is discharged at the bottom of the outer shell. In the second state, the second pressure ball is placed on the top of the outer shell. Under the action of water flow, the second pressure ball abuts against the bottom of the sliding sleeve and seals the bottom of the sliding sleeve. The sliding sleeve disengages from the second locking mechanism and slides down. The bypass hole is connected to the water eye mechanism on the sliding sleeve. In the third state, the first pressure ball is placed on the top of the outer shell. Under the action of water flow, the first pressure ball abuts against the middle of the upper sliding sleeve and blocks the bottom of the upper sliding sleeve. The upper sliding sleeve disengages from the first locking mechanism, slides down, and abuts against the top of the lower sliding sleeve. The lower sliding sleeve blocks the bypass hole.

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