Sand washing device

Abstract

The present application provides a sand washing device, which relates to the technical field of oil extraction. Among them, the sand washing device includes: a first connecting pipe for connecting a coiled tubing; a second connecting pipe fixedly opposite to the lower end of the first connecting pipe; a lower pressing body, the upper end of which is rotatably connected to the lower end of the second connecting pipe, and the inner cavity of which is sequentially communicated with the inner cavities of the first connecting pipe and the second connecting pipe to form an upward flowing channel from top to bottom; a sand washing head fixedly opposite to the lower end of the lower pressing body and having a sand washing hole channel communicated with the flowing channel; wherein, the sand washing hole channel is configured as a channel with a spiral streamline shape from top to bottom. The technical solution of the present application can solve the technical problems of poor sand washing effect and long reciprocating operation time existing in the current sand washing head.

Description

Technical Field

[0001] This application relates to the technical field of oil extraction, and particularly to a sand washing device. Background Art

[0002] At present, the hydraulic sand fracturing process is more and more widely used in the stimulation operations of horizontal wells. During the construction process, sand plugging problems often occur. Sand plugging can cause the fracturing fluid and proppant to be unable to enter the formation, affecting the fracturing construction effect and causing serious waste of materials. At the same time, the high pressure formed will damage the surface equipment and pipelines, disrupt the normal construction process, damage the formation seepage condition, cause the failure of the fracturing construction, and is more likely to cause safety accidents.

[0003] After sand plugging occurs, it is generally necessary to immediately carry out sand removal and plugging removal operations. The conventional process is to use a coiled tubing to lower a sand washing head to the sand plugging position for sand washing operations. However, the current sand washing heads have problems such as small flow rate and single sand washing direction, resulting in poor sand washing effect, long reciprocating operation time, and inability to meet the on-site use requirements. Summary of the Invention

[0004] The purpose of the embodiments of this application is to provide a sand washing device to solve the technical problems of poor sand washing effect and long reciprocating operation time existing in the current sand washing heads.

[0005] To solve the above technical problems, the embodiments of this application provide the following technical solutions:

[0006] This application provides a sand washing device, which includes: a first connecting pipe for connecting a coiled tubing;

[0007] A second connecting pipe, which is relatively fixed to the lower end of the first connecting pipe;

[0008] A lower pressing body, the upper end of which is rotatably connected to the lower end of the second connecting pipe, and the inner cavity of which is sequentially communicated with the inner cavities of the first connecting pipe and the second connecting pipe to form an upward flow channel from top to bottom;

[0009] A sand washing head, which is relatively fixed to the lower end of the lower pressing body and has a sand washing hole channel communicated with the flow channel;

[0010] Wherein, the sand washing hole channel is configured as a conical spiral line channel from top to bottom, and the winding diameter of the sand washing hole channel gradually increases from top to bottom.

[0011] In some alternative embodiments of this application, the number of the sand washing hole channels is 3, and they are spirally arranged with the same pitch and diameter and coaxial with the sand washing head.

[0012] In some alternative embodiments of this application, the taper angle of the sand washing hole channel is 2.5°.

[0013] In some modified embodiments of the present application, the interior of the second connecting pipe has an inner annular platform;

[0014] The upper end of the pressing body has an outer annular platform, which is adapted to the inner cavity of the second connecting pipe and overlaps on the upper side of the inner annular platform.

[0015] In some modified embodiments of the present application, it further includes: a bearing body disposed between the outer annular platform of the pressing body and the inner annular platform of the second connecting pipe.

[0016] In some modified embodiments of the present application, a first bearing cage and a second bearing cage, the first bearing cage is installed between the inner annular platform and the bearing body, and the second bearing cage is installed between the outer annular platform and the bearing body.

[0017] In some modified embodiments of the present application, sealing grooves are respectively provided on the inner wall of the lower end of the first connecting pipe, the outer wall of the outer annular platform, and the middle outer wall of the pressing body for accommodating sealing rings.

[0018] In some modified embodiments of the present application, the upper end surface of the outer annular platform of the pressing body has a plurality of tooling holes.

[0019] In some modified embodiments of the present application, the upper end of the sand washing head has a connecting groove, and the connecting groove is respectively communicated with the inflow channel and the sand washing hole channel;

[0020] The groove wall of the connecting groove has internal threads for threadedly connecting with the external threads on the outer wall of the lower end of the pressing body;

[0021] The side part of the connecting groove has threaded holes for connecting set screws to lock the sand washing head and the pressing body.

[0022] In some modified embodiments of the present application, it further includes: a copper sleeve, the lower end surface of the second connecting pipe has an outer annular groove, and the copper sleeve is accommodated in the outer annular groove;

[0023] When the sand washing head is locked with the pressing body, the upper end surface of the sand washing head contacts the copper sleeve.

[0024] Compared with the prior art, the sand washing device provided by the present application mainly consists of a first connecting pipe, a second connecting pipe, a pressing body, and a sand washing head, which are connected in sequence from top to bottom. The inner cavities of the first connecting pipe, the second connecting pipe, and the pressing body are sequentially communicated to form an inflow channel for sand washing liquid to flow from top to bottom. By arranging three sand washing orifices on the sand washing head that communicate with the inflow channel and are in a conical spiral shape from top to bottom, the sand washing liquid can be directly used to drive and accelerate the stable rotation of the sand washing head, and can generate an oblique jet flow to directly, comprehensively, and without dead angles wash the accumulated sand, which can improve the sand washing effect, avoid reciprocating washing, save operation time, reduce construction risks, and improve operation efficiency. By arranging a bearing body, the frictional resistance generated when the sand washing head and the pressing body rotate together can be greatly reduced, the situation of pipe string entanglement and self-locking causing blockage can be avoided, and it is beneficial to the high-speed rotation of the sand washing head. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] By referring to the following detailed description with reference to the accompanying drawings, the above and other objects, features, and advantages of the exemplary embodiments of the present application will become readily understood. In the drawings, several embodiments of the present application are shown in an exemplary rather than restrictive manner, and the same or corresponding reference numerals represent the same or corresponding parts, where:

[0026] Figure 1 Schematically shows a half-sectional structural view of the sand washing device provided by an embodiment of the present invention;

[0027] Figure 2 Schematically shows a top view structural view of the first connecting pipe of the sand washing device provided by an embodiment of the present invention;

[0028] Figure 3 For Figure 2 The cross-sectional structural view of the A-A section in;

[0029] Figure 4 Schematically shows a top view structural view of the pressing body of the sand washing device provided by an embodiment of the present invention;

[0030] Figure 5 For Figure 4 The cross-sectional structural view of the A-A section in;

[0031] Figure 6 Schematically shows a main body structural view of the sand washing head of the sand washing device provided by an embodiment of the present invention;

[0032] Figure 7 Schematically shows a perspective structural view of the sand washing head of the sand washing device provided by an embodiment of the present invention;

[0033] Figure 8 Schematically shows a front view structural view of the sand washing head of the sand washing device provided by an embodiment of the present invention;

[0034] Figure 9 is Figure 8 Schematic cross-sectional structure diagram of the A-A cross-section in

[0035] Figure 10 is Figure 8 Schematic cross-sectional structure diagram of the B-B cross-section in

[0036] Figure 11 is Figure 8 Schematic cross-sectional structure diagram of the C-C cross-section in

[0037] Figure 12 is Figure 8 Schematic cross-sectional structure diagram of the D-D cross-section in

[0038] Figure 13 Schematically shows a top view structural diagram of the copper sleeve of the sand washing device provided by an embodiment of the present invention;

[0039] Figure 14 is Figure 13 Schematic cross-sectional structure diagram of the A-A cross-section in

[0040] Explanation of reference numerals in the drawings:

[0041] The first connecting pipe 1, the second connecting pipe 2, the inner ring platform 201, the outer ring groove 202, the pressing body 3, the outer ring platform 301, the tooling hole 302, the sand washing head 4, the sand washing hole passage 401, the connecting groove 402, the threaded hole 403, the bearing body 5, the first bearing cage 6, the second bearing cage 7, the copper sleeve 8, the sealing ring 9, the sealing groove 10. Detailed implementation manners

[0042] Hereinafter, the exemplary embodiments of the present disclosure will be described in more detail with reference to the drawings. Although the exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided so that the present disclosure can be more thoroughly understood and the scope of the present disclosure can be fully conveyed to those skilled in the art.

[0043] It should be noted that, unless otherwise specified, the technical terms or scientific terms used in this application should have the ordinary meanings understood by those skilled in the art to which this application belongs.

[0044] Embodiment 1

[0045] Refer to the attached Figure 1 - attached Figure 14, Embodiment 1 of the present invention provides a sand washing device, which includes: a first connecting pipe 1 for connecting a coiled tubing; a second connecting pipe 2 fixedly opposite to the lower end of the first connecting pipe 1; a pressing body 3, the upper end of which is rotatably connected to the lower end of the second connecting pipe 2, and the inner cavity of which is sequentially communicated with the inner cavities of the first connecting pipe 1 and the second connecting pipe 2 to form a downward flowing inlet channel; a sand washing head 4 fixedly opposite to the lower end of the pressing body 3 and having a sand washing hole 401 communicated with the inlet channel; wherein, the sand washing hole 401 is configured as a downward conical spiral channel, and the winding diameter of the sand washing hole 401 gradually increases from top to bottom.

[0046] Specifically, the sand washing device proposed in this embodiment mainly includes: a first connecting pipe 1, a second connecting pipe 2, a pressing body 3 and a sand washing head 4 connected in sequence from top to bottom; among them, the first connecting pipe 1 can be processed with 42CrMo alloy steel material, and the first connecting pipe 1 and the second connecting pipe 2 can be connected by threaded connection. Refer to the appendix Figure 3 , the internal thread at the upper end of the first connecting pipe 1 can adopt the design of AMMT quick connection buckle, which is convenient for quick connection with the coiled tubing and can also be self-sealed. The lower end of the first connecting pipe 1 can adopt the structural design of ordinary internal thread plus sealing ring. A sealing groove 10 is provided inside the first connecting pipe 1 and above the ordinary internal thread for accommodating the sealing ring 9, for connecting with the external thread at the upper end of the second connecting pipe 2, and the installation is anti-loosened with thread locking glue. The pressing body 3 is rotatably connected to the lower end of the second connecting pipe 2, and the inner cavities of the first connecting pipe 1, the second connecting pipe 2 and the pressing body 3 are sequentially communicated to form a downward flowing inlet channel for the sand washing liquid; the pressing body 3 can be processed with 42CrMo alloy steel material; the sand washing head 4 and the pressing body 3 are fixedly connected by a detachable connection method, for example: a threaded connection method can be adopted, but it is not limited to this. The specific connection method is not specifically defined here and will be described in detail below. The sand washing head 4 has a sand washing hole 401 communicated with the inlet channel, and the sand washing liquid can be ejected from the lower end outlet of the sand washing hole 401. The number of sand washing holes 401 can be set to multiple, for example: it can be but not limited to arranging 3 sand washing holes 401 to improve the discharge capacity and the efficiency of the flushing operation. In order to further improve the sand washing effect, in the technical solution adopted in this embodiment, refer to the appendix Figure 7, the sand washing channel 401 is configured as a spiral channel from top to bottom, and the spiral-shaped channel has a tapered outward expansion. Its winding diameter gradually increases from top to bottom. The sand washing liquid can be used to directly drive and accelerate the rotation of the sand washing head 4, and the sand washing liquid ejected from the lower end outlet will be ejected obliquely, which can directly wash the accumulated sand to achieve the effect of all-round and dead-angle-free washing. Taking the configuration of 3 sand washing channels 401 as an example, the sand washing head 4 can be initially formed by casting 3 tapered spiral streamline-shaped sand washing channels 401 using the cast steel ZG340-640 material. Specifically, the spiral streamline parameters of the sand washing channel 401 can be configured as follows: the pitch is 75 mm, the tapered outward expansion angle is 2.5°, and the diameter of the channel is 3 mm. Of course, the specific parameters of the sand washing channel 401 are not limited to the above configuration method. In order to reduce the friction of the tool when lowering it into the well, refer to Appendix Figure 6 , the lower end surface of the sand washing head 4 can be configured as a spherical surface. After the machining of the sand washing head 4 is completed, in order to increase the wear resistance of the lower end of the sand washing head 4, the spherical surface can be subjected to high-frequency quenching treatment or surface chromium plating of 150-200 μm to increase the surface hardness to HRC45-50.

[0047] During the sand washing operation, the tool is connected to the outer thread at the bottom end of the coiled tubing string through the internal thread provided at the upper end of the first connecting pipe 1, and then is lowered to the sand plug position by using a coiled tubing vehicle group (during the lowering process, sand washing can be carried out while lowering). High-pressure sand washing liquid is pumped into the coiled tubing. The sand washing liquid will successively pass through the inlet flow channel and the designed sand washing channel 401. When the sand washing liquid passes through the tapered spiral-shaped sand washing channel 401, it can push and accelerate the rotation of the sand washing head 4. At the same time, the sand washing liquid can be ejected obliquely at the outlet end of the sand washing channel 401 to perform all-round washing on the accumulated sand. The sand-carrying liquid will be discharged back to the wellhead through the annular space between the coiled tubing and the production tubing, and finally the plugging removal operation is completed.

[0048] According to the above, an embodiment of the present invention provides a sand washing device, which mainly consists of a first connecting pipe 1, a second connecting pipe 2, a pressing body 3, and a sand washing head 4 connected in sequence from top to bottom. The inner cavities of the first connecting pipe 1, the second connecting pipe 2, and the pressing body 3 are sequentially connected to form an inlet flow channel for the sand washing liquid to flow from top to bottom. By providing a sand washing channel 401 on the sand washing head 4 that communicates with the inlet flow channel and is tapered spiral-shaped from top to bottom, the sand washing liquid can be used to directly drive and accelerate the rotation of the sand washing head 4, and can generate an oblique jet flow to directly wash the accumulated sand in an all-round and dead-angle-free manner, which can improve the sand washing effect, avoid reciprocating washing, save operation time, reduce construction risks, and improve operation efficiency.

[0049] Furthermore, refer to Appendix Figure 7 - Appendix Figure 12, in a specific implementation, the number of the sand washing channels 401 is three, and they are arranged in a spiral manner coaxially with the sand washing head 4 with the same pitch and diameter.

[0050] Specifically, in order to improve the sand washing efficiency, in the technical solution adopted by the present invention, three sand washing channels 401 can be provided, which can perform sand washing operations for large displacement models, improve the sand carrying capacity of the sand washing liquid, contribute to the backflow of large particle substances, and enhance the plugging removal effect. At the same time, in order to improve the rotation stability of the sand washing head 4, the three sand washing channels 401 are evenly distributed, and the pitch and winding diameter of each sand washing channel 401 are equal, and the axis of its spiral coincides with the central axis of the sand washing head 4. For details, please refer to the attached Figure 7 , so that the rotation of the sand washing head 4 is more stable.

[0051] Furthermore, referring to the attached Figure 1 and the attached Figure 5 , in a specific implementation, the interior of the second connecting pipe 2 has an inner ring platform 201; the upper end of the pressing body 3 has an outer ring platform 301, the outer ring platform 301 is adapted to the inner cavity of the second connecting pipe 2, and is lapped on the upper side of the inner ring platform 201.

[0052] Furthermore, referring to the attached Figure 1 , in a specific implementation, the sand washing device provided in this embodiment further includes: a bearing body 5, which is arranged between the outer ring platform 301 of the pressing body 3 and the inner ring platform 201 of the second connecting pipe 2.

[0053] Specifically, in this embodiment, an inner ring platform 201 is configured inside the lower end of the second connecting pipe 2, and correspondingly, an outer ring platform 301 is configured outside the upper end of the pressing body 3, and the outer ring platform 301 is adapted to the inner cavity of the main body part of the second connecting pipe 2. During installation, the pressing body 3 is installed from top to bottom into the inner cavity of the second connecting pipe 2, so that the outer ring platform 301 of the pressing body 3 is located on the upper side of the inner ring platform 201 of the second connecting pipe 2. In order to reduce the friction when the sand washing head 4 and the pressing body 3 rotate together, in the technical solution adopted by the present invention, a bearing body 5 can be installed between the outer ring platform 301 of the pressing body 3 and the inner ring platform 201 of the second connecting pipe 2. The bearing body 5 can include a plurality of bearing monomers. By setting the bearing body 5, the frictional resistance generated when the sand washing head 4 and the pressing body 3 rotate together can be greatly reduced, the situation of pipe string winding and self-locking causing blockage can be avoided, and it is beneficial to the high-speed rotation of the sand washing head 4. Furthermore, referring to the attached Figure 1 and the attached Figure 5, by respectively arranging sealing grooves 10 on the outer wall of the outer ring table 301 and the middle outer wall of the pressing body 3, and arranging sealing rings 9 in the sealing grooves 10, the self-sealing of the bearing body 5 can be realized, and the service life of the bearing body 5 can be improved. The above-mentioned sealing ring 9 can specifically adopt an O-ring 9; when processing the pressing body 3, the groove surfaces of the two sealing grooves 10 of the pressing body 3 need to be surface chrome-plated with a thickness of 150-200μm.

[0054] Further, referring to the attached Figure 1 , in a specific implementation, there are a first bearing cage 6 and a second bearing cage 7. The first bearing cage 6 is installed between the inner ring table 201 and the bearing body 5, and the second bearing cage 7 is installed between the outer ring table 301 and the bearing body 5.

[0055] Specifically, in the technical solution adopted by the present invention, the first bearing cage 6 and the second bearing cage 7 are respectively installed on the upper and lower end faces of the bearing body 5. Both the first bearing cage 6 and the second bearing cage 7 can be processed with GCr15 material, and the hardness requirement after material heat treatment is HRC40-45.

[0056] Further, referring to the attached Figure 4 and the attached Figure 5 , in a specific implementation, the upper end face of the outer ring table 301 of the pressing body 3 has a plurality of tooling holes 302.

[0057] Specifically, since the pressing body 3 can rotate relative to the second connecting pipe 2, when the sand washing head 4 is connected to the pressing body 3, to avoid the rotation of the pressing body 3, in the technical solution adopted by the present invention, the upper end face of the outer ring table 301 of the pressing body 3 can have a plurality of tooling holes 302. Specifically, 4 tooling holes 302 can be set. When installing the sand washing head 4, a tool is inserted into the plurality of tooling holes 302 of the pressing body 3 to make it fixed, so as to realize the reliable installation of the sand washing head 4 and the pressing body 3; the specific shape and quantity of the tooling holes 302 are not specifically limited here.

[0058] Further, referring to the attached Figure 7 and the attached Figure 9 , in a specific implementation, the upper end of the sand washing head 4 has a connecting groove 402, and the connecting groove 402 is respectively communicated with the inflow channel and the sand washing hole channel 401; the groove wall of the connecting groove 402 has internal threads for thread connection with the external threads on the lower end outer wall of the pressing body 3; the side of the connecting groove 402 has a threaded hole 403 for connecting a set screw to lock the sand washing head 4 and the pressing body 3.

[0059] Specifically, in order to achieve the relative fixed connection between the sand washing head 4 and the lower pressing body 3, in the technical solution adopted by the present invention, the upper end of the sand washing head 4 has a connection groove 402, which can communicate with the inflow channel and the sand washing hole 401, and an internal thread is machined in the connection groove 402, which can be threadedly connected with the external thread on the outer wall of the lower end of the lower pressing body 3; since the sand washing head 4 and the lower pressing body 3 need to rotate at a high speed during the sand washing operation, in order to further lock the lower pressing body 3 and the sand washing head 4, a threaded hole 403 can be provided on the side of the connection groove 402, and a set screw can be respectively connected to achieve the reliable locking and fixing of the sand washing head 4 and the lower pressing body 3; to ensure the reliability of the connection between the lower pressing body 3 and the sand washing head 4, refer to the attached Figure 7 , the number of the threaded holes 403 can be set to two, and the two threaded holes 403 are symmetrically arranged with respect to the sand washing head 4; it should be noted that the threads in the connection groove 402 and the threaded holes 403 are not shown in the attached Figure 7 .

[0060] Furthermore, refer to the attached Figure 1 , the attached Figure 13 and the attached Figure 14 , in the specific implementation, the sand washing device proposed in this embodiment further includes: a copper sleeve 8, the lower end surface of the second connecting pipe 2 has an outer ring groove 202, and the copper sleeve 8 is accommodated in the outer ring groove 202; when the sand washing head 4 is locked with the lower pressing body 3, the upper end surface of the sand washing head 4 contacts the copper sleeve 8.

[0061] Specifically, in order to reduce the friction between the sand washing head 4 and the second connecting pipe 2, in the technical solution adopted by the present invention, an outer ring groove 202 is provided on the lower end surface of the second connecting pipe 2, and the copper sleeve 8 is installed in the outer ring groove 202. When installing the sand washing head 4 and threadedly connecting the sand washing head 4 with the lower pressing body 3, the upper end surface of the sand washing head 4 contacts the lower end surface of the copper sleeve 8. After adjusting the preload of the bearing, the sand washing head 4 and the lower pressing body 3 are locked and fixed by set screws. When the sand washing head 4 rotates during the stamping operation, the copper sleeve 8 can effectively reduce the friction between the sand washing head 4 and the second connecting pipe 2; the copper sleeve 8 can be processed from copper material, and its inner diameter tolerance can adopt an interference fit of M7, and the surface finish requirements for both end surfaces of the copper sleeve 8 can be set to 0.8μm.

[0062] When assembling the sand washing device provided in this embodiment, first, the copper sleeve 8 is installed into the lower outer ring groove 202 of the second connecting pipe 2 by means of hot assembly; and the second connecting pipe 2 is erected on the assembly platform. Then, the second bearing cage 7 is installed into the upper part of the inner ring table 201 of the second connecting pipe 2. After applying No. 2 lithium-based grease on the bearing body 5, the bearing body 5 is glued to the upper end face of the second bearing cage 7. The first bearing cage 6 is installed into the second connecting pipe 2, so that the lower end face of the first bearing cage 6 is in close contact with the bearing body 5; two sealing rings 9 are respectively installed into the sealing grooves 10 on the outer ring table 301 of the lower pressing body 3 and the sealing grooves 10 in the middle of the lower pressing body 3. Then, the outer ring table 301 of the lower pressing body 3 with the installed sealing rings 9 is inserted into the upper end hole of the second connecting pipe 2 upward, so that the outer ring table 301 of the lower pressing body 3 is in close contact with the upper end face of the first bearing cage 6; a tooling is inserted into a plurality of tooling holes 302 on the upper end face of the outer ring table 301 of the lower pressing body 3 to make it fixed, and the upper internal thread of the sand washing head 4 is threadedly connected with the lower external thread of the lower pressing body 3, so that the upper end face of the sand washing head 4 is in contact with the lower end face of the copper sleeve 8. After adjusting the pre-tightening force of the bearing body 5, a set screw is installed into the threaded hole 403 of the sand washing head 4 to lock and fix the sand washing head 4 and the lower pressing body 3; the sealing ring 9 is installed into the sealing groove 10 at the lower end of the first connecting pipe 1, and thread fastening glue is evenly applied on the lower internal thread of the first connecting pipe 1. The upper external thread of the assembled second connecting pipe 2 is connected with the lower internal thread of the first connecting pipe 1 and tightened according to the specified torque. Thus, the assembly of the sand washing device is completed.

[0063] It should be noted that in the description of this specification, the orientation or positional relationship indicated by terms such as "upper" and "lower" is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, so it cannot be understood as a limitation to the present invention; terms such as "connection", "installation", and "fixation" should all be understood in a broad sense. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected or indirectly connected through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0064] In the description of this specification, the descriptions of terms such as "one embodiment", "some embodiments", "specific embodiments", etc. mean that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0065] As described above, it is only the specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention can easily think of changes or substitutions, which should all be covered by the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope of the claims.

Claims

1. A sand flushing device, characterized in that, Comprising: A first connecting pipe for connecting a coiled tubing; A second connecting pipe fixedly opposed to the lower end of the first connecting pipe; A lower pressing body, the upper end of which is rotatably connected to the lower end of the second connecting pipe, and the inner cavity of which is sequentially communicated with the inner cavities of the first connecting pipe and the second connecting pipe to form a downward inflow channel; A sand washing head fixedly opposed to the lower end of the lower pressing body and having a plurality of sand washing channels communicated with the inflow channel; Wherein, the sand washing channels are configured as channels in a conical spiral shape from top to bottom, and the winding diameter of the sand washing channels gradually increases from top to bottom, and the plurality of sand washing channels are spirally arranged with the same pitch and winding diameter and coaxially with the sand washing head.

2. The sand washing device according to claim 1, wherein The taper angle of the sand washing channel is 2.5°.

3. The sand washing device according to claim 1, wherein The interior of the second connecting pipe has an inner ring platform; The upper end of the lower pressing body has an outer ring platform, the outer ring platform is adapted to the inner cavity of the second connecting pipe and is lapped on the upper side of the inner ring platform.

4. The sand washing device according to claim 3, characterized in that, Further comprising: A bearing body disposed between the outer ring platform of the lower pressing body and the inner ring platform of the second connecting pipe.

5. The sand washing device according to claim 4, characterized in that, Further comprising: A first bearing cage and a second bearing cage, the first bearing cage is installed between the inner ring platform and the bearing body, and the second bearing cage is installed between the outer ring platform and the bearing body.

6. The sand washing device according to claim 3, wherein Sealing grooves are respectively provided on the inner wall of the lower end of the first connecting pipe, the outer wall of the outer ring platform and the middle outer wall of the lower pressing body for accommodating sealing rings.

7. The sand washing device according to claim 3, wherein The upper end surface of the outer ring platform of the lower pressing body has a plurality of tooling holes.

8. The sand washing device according to claim 1, wherein The upper end of the sand washing head has a connecting groove, and the connecting groove is respectively communicated with the inflow channel and the sand washing channel; The groove wall of the connecting groove has an internal thread for threadedly connecting with the external thread on the outer wall of the lower end of the lower pressing body; The side of the connecting groove has a threaded hole for connecting a set screw to lock the sand washing head and the lower pressing body.

9. The sand washing device according to claim 8, characterized in that, Further comprising: A copper sleeve, the lower end surface of the second connecting pipe has an outer ring groove, and the copper sleeve is accommodated in the outer ring groove; When the sand washing head is locked with the lower pressing body, the upper end surface of the sand washing head contacts the copper sleeve.

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