A high-efficiency sand flushing and cleaning tool for oil and gas wells

Abstract

This invention discloses a high-efficiency sand-flushing and cleaning tool for oil and gas wells, relating to the field of downhole operation technology. It includes a sand-flushing sub, with a water-guiding cavity inside. Several cutting components are arranged on the outer wall of the sub for scraping impurities from the well wall. A first flow-guiding component is located at the bottom of the sub for guiding the liquid ejected from the inclined water outlet. A second flow-guiding component is located outside the first flow-guiding component for exporting the liquid guided by the first flow-guiding component. A third flow-guiding component is located at the bottom of the sub for vertically exporting a portion of the liquid inside the water-guiding cavity. This invention maximizes hydraulic utilization by distributing the high-pressure fluid flow through the tool in three stages. It solves the problems of potential stuck drill bits during well setup and the limited sand-flushing range of the sand-flushing sub, leading to incomplete sand flushing.

Description

Technical Field

[0001] This invention relates to the field of downhole operation technology, specifically to a high-efficiency sand flushing and cleaning tool for oil and gas wells. Background Technology

[0002] The high-efficiency sand flushing tool is the core component for sand flushing operations in the dual-channel drill pipe sand flushing process. It is connected to the dual-channel drill pipe at the upper end. The core function is to flush sand through the lower jet nozzle and suck sand through the middle jet nozzle, realizing the "sand flushing-carrying" operation. The mixed sand liquid is returned to the wellhead through the inner tube of the dual-channel drill pipe.

[0003] Traditional sand-washing tools are mostly straight-cylinder, flat-bottomed and without guides. Such structures are prone to problems such as sand hitting the casing, sand bridging, and scraping the inner wall of the casing during the process of being lowered into the well. They have poor passability in horizontal wells, highly deviated wells, narrow-diameter wells and curved sections, and there is a risk of encountering obstruction and stuck drill.

[0004] Meanwhile, the sandblasting sub relies on the bottom sand-blasting nozzle to achieve direct sand blasting and circumferential sand blasting through small circumferential holes. The sand blasting coverage is limited, and the outer wall of the sub is a smooth cylindrical surface without scraping blades, tilting grooves, or wall scraping structures. It cannot effectively clean the sand accumulation on the outside, especially the sand adhering to the well wall, the sand bed at the bottom of the casing, and the sand settled at the bottom edge of the horizontal section. This may result in incomplete sand cleaning operations. Summary of the Invention

[0005] This invention overcomes the shortcomings of the prior art and proposes a high-efficiency sand flushing and cleaning tool for oil and gas wells to solve the problems of stuck drill bit when the cleaning tool is run into the well and the limited sand flushing range of the sand-spraying sub, which leads to incomplete sand flushing.

[0006] This invention is achieved through the following technical solution: A high-efficiency sand flushing tool for oil and gas wells includes a sand flushing sub. The sub has a water guiding cavity inside and several inclined water outlets on its sidewalls, each connected to the water guiding cavity. Several cutting components are arranged in a ring array on the outer wall of the sub, used to scrape away impurities from the well wall. A first flow guiding component is located at the bottom of the sub, guiding the liquid ejected from the inclined water outlets. A second flow guiding component is located outside the first flow guiding component, discharging the liquid guided by the first flow guiding component. A third flow guiding component is located at the bottom of the sub, vertically discharging a portion of the liquid inside the water guiding cavity.

[0007] Furthermore, the cutting assembly includes a cutting strip, which is fixedly connected to the outer wall of the sandblasting section. The side wall of the cutting strip is provided with a number of spiral cutting grooves, which are vertically and equidistantly distributed on the side wall of the cutting strip.

[0008] Furthermore, the first flow guiding component includes a plurality of first vanes, which are disposed outside the sand flushing section and arranged in a ring array. The jet direction of the inclined water outlet is directed toward the inner side of the first vanes, so that the high-speed jet ejected from the inclined water outlet pushes the first vanes away.

[0009] Furthermore, the first flow guiding component also includes several first elastic materials, which are fixedly connected between each pair of adjacent first vanes. The outer walls of the several first vanes are fixedly connected with connecting pads, and the connecting pads are tightly fitted to the second flow guiding component.

[0010] Furthermore, the first flow guiding component also includes several inclined surfaces, which are respectively disposed on the inner side of the bottom end of the first vane, and several water inlet grooves are formed on the outer wall of each inclined surface.

[0011] Furthermore, the first flow guiding assembly also includes several first flexible hinges, one end of which is fixedly connected to the top of the first wing, and the other end of each first flexible hinge is fixedly connected to the outer wall of the sand-flushing section.

[0012] Furthermore, the second flow guiding assembly includes a plurality of second vanes, which are respectively disposed outside the first vane, and each second vane is attached to the end of the connecting pad.

[0013] Furthermore, the second flow guiding assembly also includes several second elastic materials, which are fixedly connected between each pair of adjacent second winglets. Several ribs are fixedly connected to the inner side of each second winglet, and inclined flow guiding holes are symmetrically opened in the middle of each second winglet. The intersection of the orientations of two inclined flow guiding holes falls on the corresponding cutting strip.

[0014] Furthermore, the second flow guiding assembly also includes several second flexible hinges, one end of which is fixedly connected to the top of the second vane, and the other end of each second flexible hinge is fixedly connected to the outer wall of the sand flushing section. A wedge-shaped water guide platform is provided at the upper end of the several second flexible hinges, and the wedge-shaped water guide platform is fixedly connected to the outer wall of the sand flushing section.

[0015] Furthermore, the third flow guiding component includes a conical water guide head, which is fixedly connected to the bottom end of the sand flushing section. The outer wall of the conical water guide head is provided with a threaded water guide groove, and the inner wall of the bottom end of the conical water guide head is provided with a vertical water outlet hole, which is connected to the water guiding cavity.

[0016] The beneficial effects of this invention compared to the prior art are as follows: 1. This invention utilizes the coordinated design of an inclined water outlet, a first flow guiding component, a second flow guiding component, and a third flow guiding component to distribute the high-pressure liquid flow through the tool in three stages. The first stage of energy drives the dual-stage vanes to adaptively open, forming a large-diameter flow guiding funnel that directly impacts the outer sand layer. The second stage of energy uses the water inlet groove and ribs on the inner side of the vanes to disturb the liquid flow, maintaining a high-intensity turbulent state and significantly improving sand carrying and return efficiency. The third stage of energy is diverted through the inclined flow guiding hole and the threaded water guiding groove to directionally clean the cutting component and form a rotating jet to assist in sand breaking. There is no energy loss throughout the process, and the hydraulic utilization rate is maximized.

[0017] 2. This invention uses a high-pressure jet to propel the first and second blades outward in sequence, forming a two-stage flow-guiding flare that can cover the entire circumference of the casing annulus. This effectively solves the problems of limited sand flushing range, low-side sand accumulation in horizontal sections, and inadequate cleaning of sand adhering to the well wall in traditional straight-tube tools. At the same time, the blades are connected by flexible hinges and elastic materials, which can adaptively contract and expand with the well diameter. This significantly reduces the probability of top sand, sand bridges, and casing scraping when the blades are lowered into the wellbore, and significantly improves the passability in horizontal wells, highly deviated wells, reduced-diameter wells, and curved well sections, reducing the risk of stuck pipe.

[0018] 3. This invention uses a cutting bar with a spiral cutting groove on the outer wall of the sand-washing short section to scrape away stubborn impurities and accumulated sand from the well wall as the tool descends. The spiral groove can accommodate and guide sand particles, preventing sand accumulation from clogging the operation. The inclined guide hole on the second wing can accurately spray high-pressure liquid flow onto the cutting bar and spiral groove to flush away the attached sand particles in real time, keeping the cutting structure unobstructed and efficient. This fundamentally solves the defects of traditional tools that lack a wall-scraping structure, are not thoroughly cleaned, and are prone to sand accumulation and clogging.

[0019] 4. This invention uses a bottom conical water guide head combined with a threaded water guide groove to convert part of the liquid flow into a spiral rotating jet, which breaks up hard sand beds and dense sand deposits by shearing. Combined with the direct sand flushing through the vertical water outlet, it forms a composite sand flushing mode of rotational shearing combined with vertical direct flushing. At the same time, the wedge-shaped water guide platform mechanically limits the blades to prevent excessive opening. With the help of elastic materials and flexible hinges, automatic reset is achieved. The tool structure is stable and reliable, and can operate continuously for a long time, which greatly improves the overall efficiency and success rate of downhole sand flushing and cleaning. At the same time, the inclined guide hole cleans the surface of the cutting strip, reduces the probability of sand accumulation, and improves the cutting ability of the cutting strip. Attached Figure Description

[0020] Figure 1 A frontal three-dimensional structural diagram of a high-efficiency sand-washing tool for oil and gas wells; Figure 2 A frontal cross-sectional three-dimensional structural diagram of a high-efficiency sand-washing tool for oil and gas wells; Figure 3 A schematic diagram of the three-dimensional structure of the sand-washing short section from an upward view; Figure 4 A three-dimensional structural diagram of the first and second flow guiding components; Figure 5 This is a three-dimensional cross-sectional structural diagram of the first flow guiding component. Figure 6 This is a three-dimensional cross-sectional structural diagram of the second flow guiding component. Figure 7 for Figure 2 Enlarged 3D structural diagram at point A; Figure 8 for Figure 3 Enlarged 3D structural diagram at point B.

[0021] Figure label: 1. Sand-washing short section; 2. Water guiding cavity; 3. Cutting assembly; 301. Cutting strip; 302. Spiral cutting groove; 4. First flow guiding assembly; 401. First vane; 402. First elastic material; 403. Inclined surface; 404. Water inlet groove; 405. First flexible hinge; 406. Connecting pad; 5. Second flow guiding assembly; 501. Second vane; 502. Second elastic material; 503. Rib; 504. Inclined flow guiding hole; 505. Second flexible hinge; 506. Wedge-shaped water guiding platform; 6. Third flow guiding assembly; 601. Conical water guiding head; 602. Threaded water guiding groove; 603. Vertical water outlet hole; 7. Inclined water outlet hole. Detailed Implementation

[0022] To make the technical problems to be solved, the technical solutions, and the beneficial effects of this invention clearer, the invention will be further described in detail with reference to the embodiments and accompanying drawings. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention. The technical solutions of this invention are described in detail below with reference to the embodiments and accompanying drawings, but the scope of protection is not limited thereto.

[0023] Please see Figures 1 to 8This embodiment proposes a high-efficiency sand flushing tool for oil and gas wells, including a sand flushing section 1. The sand flushing section 1 has a water guiding cavity 2 inside. Several inclined water outlet holes 7 are formed on the side wall of the sand flushing section 1, each of which is connected to the water guiding cavity 2. Several cutting components 3 are arranged in a ring array on the outer wall of the sand flushing section 1. The cutting components 3 are used to scrape away impurities from the well wall. A first flow guiding component 4 is provided at the bottom of the sand flushing section 1. The first flow guiding component 4 is used to guide the liquid ejected from the inclined water outlet holes 7. A second flow guiding component 5 is provided outside the first flow guiding component 4. The second flow guiding component 5 is used to further guide the liquid guided by the first flow guiding component 4. The bottom end of the sand flushing section 1 is provided with a third flow guide component 6, which is used to vertically discharge part of the liquid inside the water guiding cavity 2. The cutting component 3 includes a cutting strip 301, which is fixedly connected to the outer wall of the sand flushing section 1. The side wall of the cutting strip 301 is provided with several spiral cutting grooves 302. The spiral cutting grooves 302 are arc-shaped inclined grooves similar to a spiral structure. During cutting, this structure facilitates the entry of sand and gravel into the spiral cutting grooves 302, which facilitates the containment and guidance of the cut sand and gravel, provides a certain space for the escape of sand and gravel, and avoids the accumulation of sand and gravel affecting subsequent operations. Several spiral cutting grooves 302 are vertically and equidistantly distributed on the side wall of the cutting strip 301.

[0024] like Figures 4 to 6 As shown, the first flow guiding assembly 4 includes a plurality of first vanes 401, which are disposed on the outside of the sand-washing section 1 and arranged in a ring array. The upper half of the inner side of the first vane 401 is inclined and nearly perpendicular to the spray direction of the inclined water outlet 7, so that the high-speed jet sprayed from the inclined water outlet 7 can push the first vanes 401 away. The first flow guiding assembly 4 also includes a plurality of first elastic materials 402, which are fixedly connected to each of every two adjacent first vanes 401. The first elastic material 402 is a flexible elastic material with a near-trapezoidal curved surface. During the opening process of the first wing 401, the first elastic material 402 can be stretched to adapt to the opening state of the first wing 401. A connecting soft pad 406 is fixedly connected to the outer wall of several first wing 401s. The connecting soft pad 406 has a floating structure and is closely attached to the second wing 501 of the second flow guide assembly 5, so that the thrust can be pushed to the second wing 501 when the first wing 401 opens.

[0025] The first flow guiding assembly 4 also includes several inclined surfaces 403, which are respectively disposed on the inner side of the bottom end of the first vane 401. Each inclined surface 403 has several water-guiding grooves 404 on its outer wall. The inclined surfaces 403 are used to guide the high-pressure liquid, while the water-guiding grooves 404 divert and guide the high-pressure liquid. The first flow guiding assembly 4 also includes several first flexible hinges 405, one end of which is fixedly connected to the top end of the first vane 401, and the other end of each first flexible hinge 405 is fixedly connected to the outer wall of the sand-flushing section 1. The first flexible hinges 405 have good elasticity, facilitating shape adjustment according to the expansion state and also facilitating the repositioning of the first vane 401.

[0026] like Figures 4 to 8 As shown, the second flow guiding assembly 5 includes a plurality of second vanes 501, which are respectively disposed outside the first vane 401. Each second vane 501 is attached to the end of the connecting pad 406. The second flow guiding assembly 5 also includes a plurality of second elastic materials 502, which are respectively fixedly connected between every two adjacent second vanes 501. The second elastic materials 502 are flexible elastic materials and have a near-trapezoidal curved surface, which facilitates the stretching of the second elastic materials 502 during the opening of the second vane 501 to adapt to the opening state of the second vane 501. The inner surface of each second vane 501... Several ribs 503 are fixedly connected to each side. The ribs 503 protrude from the surface of the second wing 501 and serve as reinforcing ribs of the second wing 501, enhancing the bending stiffness and impact resistance of the second wing 501. At the same time, they actively disturb the liquid close to the surface of the second wing 501, forcing the liquid to become turbulent and improving the sand carrying efficiency. Each second wing 501 has symmetrically opened inclined guide holes 504 in the middle. The inclined guide holes 504 have a pairwise symmetrical structure, and the intersection of the orientation of two inclined guide holes 504 falls on the corresponding cutting strip 301, which facilitates the inclined guide holes 504 to guide the high-pressure water flow to both sides of the cutting strip 301, thereby facilitating the cleaning of the cutting strip 301.

[0027] The second flow guiding assembly 5 also includes several second flexible hinges 505. The second flexible hinges 505 have good elasticity, which makes it easy to adjust their shape according to the expansion state, and also makes it easy to push the second vane 501 to reset. One end of each of the several second flexible hinges 505 is fixedly connected to the top of the second vane 501, and the other end of each second flexible hinge 505 is fixedly connected to the outer wall of the sand flushing section 1. The upper end of the several second flexible hinges 505 is provided with a wedge-shaped water guide platform 506. The wedge-shaped water guide platform 506 is used to mechanically limit the second vane 501. When the second vane 501 is unfolded to the maximum working angle, the wedge-shaped water guide platform 506 contacts its surface, thereby preventing the second vane 501 from being over-opened. The wedge-shaped water guide platform 506 is fixedly connected to the outer wall of the sand flushing section 1.

[0028] like Figures 3 to 8 As shown, the third flow guiding component 6 includes a conical water guide head 601, which is fixedly connected to the bottom end of the sand flushing section 1. The outer wall of the conical water guide head 601 is provided with a threaded water guide groove 602, and the inner wall of the bottom end of the conical water guide head 601 is provided with a vertical water outlet hole 603, which is connected to the water guiding cavity 2.

[0029] The working principle of the technical solution provided by this invention is as follows: During operation, after the sand-flushing section 1 is inserted into the well, the cutting bar 301 moves along the direction of the sand-flushing section 1. The cutting bar 301 drives the spiral cutting groove 302 to scrape the inner wall of the well. When the sand-flushing section 1 reaches the target position, high-pressure liquid enters the water guiding chamber 2. Part of the high-pressure liquid is guided into the interior through the water guiding chamber 2, and then the high-pressure liquid is discharged to the inner side of the first vane 401 through the inclined water outlet 7. At this time, the normal component of the high-pressure jet pushes the enclosed structure composed of several first vanes 401 to expand outward, forming a first-stage guide bell mouth. At the same time, the axial component of the high-pressure jet acts... The thrust is directly impacted and broken by the outer sand layer, and then transmitted to the connecting pad 406 through the first vane 401. The connecting pad 406 further pushes the enclosed structure composed of several second vanes 501 to expand outward, thereby forming a secondary flow guide bell mouth. At the same time, the high-pressure liquid is guided to the inner side of the second vane 501 through the water inlet 404. Then, the ribs 503 cause the laminar boundary layer on the inner surface of the second vane 501 to form high-pressure turbulence. Then, the high-pressure turbulence is discharged through the second vane 501 and flushed to wash the sand and gravel in the well. At the same time, some of the high-pressure liquid is sprayed out through the vertical water outlet 603 for vertical flushing.

[0030] Furthermore, when the inclined water outlet 7 discharges high-pressure liquid, part of the high-pressure liquid flows towards the sand flushing section 1 under the diversion effect of the first vane 401. The flow direction of this part of the liquid is forcibly changed by the threaded water guide groove 602 on the surface of the conical water guide head 601, so that this part of the high-pressure liquid obtains tangential force when flowing along the threaded water guide groove 602. Then, the high-pressure liquid is transformed into a spiral-forward rotating jet through the tangential force, and the spiral rotating jet shears and breaks the sand layer.

[0031] Furthermore, when the high-pressure liquid flows through the inner side of the second vane 501, it passes through the inclined guide hole 504 in the middle of the second vane 501, and then the liquid is discharged obliquely upward through the inclined guide hole 504. Under the guidance of the inclined guide hole 504, the liquid is sprayed onto the cutting bar 301, thereby cleaning the cutting bar 301 and the spiral cutting groove 302 with high-pressure liquid. After cleaning, the high-pressure liquid flows to the outer side of the second vane 501 under the guidance of the wedge-shaped water guide platform 506, and the high-pressure liquid is discharged through the second vane 501.

[0032] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A high-efficiency sand-washing tool for oil and gas wells, characterized in that, The system includes a sand flushing section (1), which has a water guiding cavity (2) inside. The side wall of the sand flushing section (1) has several inclined water outlet holes (7), each of which is connected to the water guiding cavity (2). The outer wall of the sand flushing section (1) is provided with several cutting components (3), which are arranged in a ring array. The cutting components (3) are used to scrape off impurities from the well wall. The bottom end of the sand flushing section (1) is provided with a first flow guiding component (4), which is used to guide the liquid ejected from the inclined water outlet holes (7). The outside of the first flow guiding component (4) is provided with a second flow guiding component (5), which is used to discharge the liquid guided by the first flow guiding component (4). The bottom end of the sand flushing section (1) is provided with a third flow guiding component (6), which is used to vertically discharge some of the liquid inside the water guiding cavity (2).

2. The high-efficiency sand-washing tool for oil and gas wells according to claim 1, characterized in that, The cutting assembly (3) includes a cutting strip (301), which is fixedly connected to the outer wall of the sand-filling short section (1). The side wall of the cutting strip (301) is provided with a number of spiral cutting grooves (302), which are vertically and equidistantly distributed on the side wall of the cutting strip (301).

3. The high-efficiency sand flushing and cleaning tool for oil and gas wells according to claim 2, characterized in that, The first flow guiding component (4) includes a plurality of first blades (401), which are disposed outside the sand flushing section (1) and arranged in a ring array. The jet direction of the inclined water outlet (7) is directed toward the inside of the first blades (401), so that the high-speed jet ejected by the inclined water outlet (7) pushes the first blades (401) away.

4. The high-efficiency sand flushing and cleaning tool for oil and gas wells according to claim 3, characterized in that, The first flow guiding component (4) also includes several first elastic materials (402), which are fixedly connected between each pair of adjacent first blades (401). The outer walls of the several first blades (401) are fixedly connected with connecting pads (406), and the connecting pads (406) are tightly attached to the second flow guiding component (5).

5. The high-efficiency sand-washing tool for oil and gas wells according to claim 4, characterized in that, The first flow guiding component (4) also includes several inclined surfaces (403), which are respectively arranged on the inner side of the bottom end of the first wing (401), and several water inlet grooves (404) are opened on the outer wall of each inclined surface (403).

6. The high-efficiency sand-washing tool for oil and gas wells according to claim 5, characterized in that, The first flow guide assembly (4) also includes several first flexible hinges (405), one end of which is fixedly connected to the top of the first wing (401), and the other end of each first flexible hinge (405) is fixedly connected to the outer wall of the sand-filling short section (1).

7. The high-efficiency sand flushing and cleaning tool for oil and gas wells according to claim 4, characterized in that, The second flow guide assembly (5) includes a plurality of second winglets (501), which are respectively disposed outside the first winglet (401), and each second winglet (501) is attached to the end of the connecting pad (406).

8. The high-efficiency sand flushing and cleaning tool for oil and gas wells according to claim 7, characterized in that, The second flow guiding component (5) also includes a number of second elastic materials (502), which are fixedly connected between each pair of adjacent second blades (501). Each second blade (501) has a number of ribs (503) fixedly connected to its inner side. Each second blade (501) has symmetrically opened inclined flow guiding holes (504) in the middle, and the intersection of the two inclined flow guiding holes (504) falls on the corresponding cutting strip (301).

9. The high-efficiency sand flushing and cleaning tool for oil and gas wells according to claim 7, characterized in that, The second flow guiding assembly (5) also includes several second flexible hinges (505), one end of which is fixedly connected to the top of the second wing (501), and the other end of each second flexible hinge (505) is fixedly connected to the outer wall of the sand flushing section (1). A wedge-shaped water guide platform (506) is provided at the upper end of the several second flexible hinges (505), and the wedge-shaped water guide platform (506) is fixedly connected to the outer wall of the sand flushing section (1).

10. The high-efficiency sand flushing and cleaning tool for oil and gas wells according to claim 1, characterized in that, The third flow guiding component (6) includes a conical water guide head (601), which is fixedly connected to the bottom end of the sand flushing section (1). The outer wall of the conical water guide head (601) is provided with a threaded water guide groove (602), and the inner wall of the bottom end of the conical water guide head (601) is provided with a vertical water outlet hole (603), which is connected to the water guiding cavity (2).

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