Oil and gas wellbore cleaning tool assembly and cleaning method thereof

Abstract

The present invention discloses a wellbore cleaning tool combination for oil and gas production and a cleaning method thereof, and specifically relates to the technical field of downhole tools for oil and gas production, wherein the tool combination comprises an end short section and an intermediate short section, both of which are hollow tubular structures, and both ends of the end short section and the intermediate short section have threaded joints, wherein the bottom of the end short section has a nozzle mounting hole A arranged downward, and the side wall of the end short section has a nozzle mounting hole B, and the nozzle mounting holes B are evenly distributed along the circumference of the end short section; the side wall of the intermediate short section has a nozzle mounting hole C, and the nozzle mounting holes C are evenly distributed along the circumference of the intermediate short section, and the nozzle mounting hole C has a cleaning nozzle installed in a rotatable manner, and the cleaning nozzle has at least three spiral water holes. Beneficial effects: It can meet various well repair needs of oil and gas wells, achieve better cleaning effects, and at the same time improve cleaning efficiency, relatively reduce operating costs, etc.

Description

Technical Field

[0001] The invention relates to the technical field of downhole tools for oil and gas production, and in particular to a wellbore cleaning tool combination for oil and gas production wells and a cleaning method thereof. Background Art

[0002] In the later stage of oil well production, sand production from the bottom of the well and wax deposition on the wellbore wall often occur due to reasons such as decreased formation pressure, changes in fluid properties, and aging of the wellbore structure. The emergence of these phenomena seriously affects the overall production performance of the oil well and the oil and gas recovery rate. After the oil well produces sand, if the fluid flow in the well cannot bring all the sand to the ground, the sand in the well will gradually settle and form a sand column, blocking the oil outlet channel, increasing flow resistance, and reducing or even stopping the oil well production. At the same time, sand production will also cause wear and damage to downhole equipment, increase maintenance costs, and even cause downhole sand jam accidents, endangering personnel safety.

[0003] On the other hand, wax deposition inside oil wells is very common, especially in the process of waxy crude oil production. Due to the decrease in formation pressure and temperature, the wax components in the crude oil are separated or dissolved, forming crystals or colloids, which are adsorbed or deposited on the equipment. These wax deposits will affect the operating efficiency of the equipment, increase production costs, and even cause equipment damage or wellbore blockage.

[0004] In order to solve these problems, regular wax removal and sand flushing are important ways to improve oil well production efficiency and extend oil well life. However, there is currently no overall efficient tool for wax removal and well washing, which means that the next trip of the tubing string can only be carried out in a single process, which seriously affects the construction efficiency, construction cycle and well repair cost. Especially during the wax removal operation, the wax dispersed by the lower flushing can easily continue to adhere to the inner wall of the wellbore during the upward return process, which relatively reduces the wax removal effect. Therefore, it is an urgent need for current oilfield development to develop a comprehensive tool that can simultaneously meet the needs of wax removal and sand flushing and has a good cleaning effect. Summary of the invention

[0005] In view of this, the present invention provides a production oil and gas well wellbore cleaning tool combination, aiming to solve the current production oil and gas well wellbore cleaning poor effect and low efficiency technical problems.

[0006] To achieve the above purpose, the technical solution of the present invention is as follows:

[0007] A wellbore cleaning tool assembly for oil and gas production, the key of which is: comprising an end short section and an intermediate short section both of which are hollow tubular structures, both ends of the end short section and the intermediate short section have threaded joints, wherein the bottom of the end short section has a nozzle mounting hole A arranged downward, and the side wall of the end short section has a nozzle mounting hole B, and the nozzle mounting holes B are evenly distributed along the circumference of the end short section;

[0008] The side wall of the intermediate short section has nozzle mounting holes C, the nozzle mounting holes C are evenly distributed along the circumference of the intermediate short section, and a cleaning nozzle is rotatably mounted in the nozzle mounting holes C, and the cleaning nozzle has at least three spiral water holes.

[0009] A combination of two short sections is used. During the cleaning operation, the end short section can be used to perform a main cleaning of the wellbore, while the middle short section can perform a secondary auxiliary cleaning of the wellbore to prevent the adhesion of the removed matter during the return process, thereby greatly improving the cleaning effect. The cleaning nozzle on the middle short section is in a rotating state during operation, and its outlet flow contacts the wellbore in a surface shape. Compared with the linear flow of the traditional fixed nozzle, it can clean the inner wall to the maximum extent, avoid or reduce the missed area, and help to further ensure the cleaning quality.

[0010] Preferably, the nozzle installation hole A includes a main spray hole and N auxiliary spray holes, wherein the axis of the main spray hole coincides with the axis of the end short section, and the N auxiliary spray holes are evenly distributed on the circumferential outer side of the main spray hole and are tilted outward. With the above scheme, the nozzle jet of the main spray hole is mainly used for sand flushing operations, which can exert the greatest impact on the sand at the bottom of the well, while the nozzle jet of the auxiliary spray hole can not only flush the sand at the outer periphery of the bottom of the well, which is conducive to the reflux of the sand, but also can perform wax cleaning on the inner wall of the wellbore.

[0011] As a preference: the nozzle mounting holes B are staggered and evenly distributed along the axis of the end short section. With the above solution, more nozzle mounting holes B can be provided without affecting the strength of the end short section to install the nozzles, so that the jet area covers the circumferential side wall of the inner cylinder, which is conducive to achieving a better cleaning effect.

[0012] As a preference, the nozzle mounting hole B is tilted toward the upper end of the end short section. With the above solution, because the nozzle mounting hole A is downward, and the nozzle mounting hole B is arranged upward, the two are substantially opposite, and the jets of the corresponding nozzles are combined to flush the attachments on the upper and lower sides of the cylinder wall, which can be removed better and faster, thereby achieving a better cleaning effect.

[0013] Preferably, the sliding sleeve comprises a hollow tubular main body and a limiting portion formed at one end of the main body, and a liquid guiding channel is provided in the sliding sleeve;

[0014] The end short section comprises a first short section and a second short section connected in an integral manner, wherein the first short section has an upper guide channel adapted to the main body, the outer diameter of the limiting portion is larger than the diameter of the upper guide channel, and the second short section has a lower guide channel adapted to the limiting portion;

[0015] In the initial state, the sliding sleeve is installed in the first short section through the shear pins, and the main body corresponds to the position of the nozzle mounting hole B and blocks the nozzle mounting hole B.

[0016] By adopting the above scheme, the nozzle jets in the nozzle mounting hole A and the nozzle mounting hole B can be switched by throwing a ball, thereby meeting more cleaning needs and helping to improve cleaning efficiency.

[0017] As a preferred embodiment, the limiting part includes a disc-shaped body and petal-shaped bodies evenly distributed at the bottom of the disc-shaped body. The above solution can prevent the sliding sleeve from getting stuck, facilitate the disassembly and assembly of the sliding sleeve, and improve the disassembly and assembly efficiency.

[0018] As a preference: the diameter of the main spray hole is larger than the diameter of the auxiliary spray hole. With the above solution, when performing sand blasting operation, the nozzle jet of the main spray hole can achieve a good sand blasting effect.

[0019] As a preferred embodiment, the flow area of ​​the spiral water eye gradually decreases from inside to outside along the radial direction of the middle short section. With the above solution, the flow area gradually decreases, which can achieve the effect of self-pressurization, thereby increasing the ejection speed of the jet flow and having a greater impact force.

[0020] As a preferred embodiment, the nozzle mounting holes C are evenly distributed in a spiral along the length direction of the intermediate short section. With the above solution, there is only one nozzle mounting hole C in a unit axial section, which can fully ensure the overall strength of the intermediate short section and extend its service life. On the other hand, the cleaning nozzles with spiral distribution, combined with the self-rotation of the cleaning nozzles and the rotation of the intermediate short section, can perform repeated jet surface cleaning with full coverage of the inner cylinder wall, and have a better cleaning effect.

[0021] In order to achieve better cleaning effect and cleaning efficiency, the present invention also provides a production oil and gas wellbore cleaning method, the main points of which are to use the above-mentioned production oil and gas wellbore cleaning tool combination and perform the following steps:

[0022] S1: Install each adaptive nozzle in the nozzle mounting hole A and the nozzle mounting hole B;

[0023] S2: The end short section is passed through the oil pipe string and lowered into the wellbore of the oil and gas well to be cleaned. During the drilling process, the oil pipe string is supplied with liquid through the surface liquid supply equipment, and the inner wall of the wellbore is cleaned from top to bottom by the jet flow of the nozzle in the nozzle installation hole A;

[0024] S3: Observe the return of the wellhead annulus. If there is no wax return, connect the intermediate short joint to the tubing string and continue to drill down for cleaning. While cleaning the lower part, use the jet flow of the cleaning nozzle to clean the upper inner cylinder wall for the second time.

[0025] S4: When the end sub reaches the target layer, if sand flushing is required, rotate the pipe and increase the surface fluid supply for a period of time to perform sand flushing. After the wellhead annulus returns without sand sediment, put in the steel ball;

[0026] If sand flushing is not required, a steel ball is directly put in. The diameter of the steel ball is larger than the diameter of the liquid guide channel. The steel ball blocks the liquid guide channel, increases the surface liquid supply, and destroys the shear pin. The sleeve moves downward, and the inner end of the nozzle mounting hole B is exposed. The jet flow of the nozzle in the nozzle mounting hole B is used to clean the inner wall of the wellbore from bottom to top.

[0027] S4: Pull out the pipe string and end the cleaning operation.

[0028] With the above scheme, during the drilling process, the jet flow of the nozzle in the nozzle installation hole A is used to clean the inner wall of the wellbore from top to bottom. When reaching the target layer, if sand flushing is required, the jet flow of the nozzle in the nozzle installation hole A can achieve a good sand flushing effect. If sand flushing is not required or the sand flushing operation is completed, the nozzle in the nozzle installation hole A can be blocked by throwing a ball, and the nozzle in the nozzle installation hole B works, and the inner tube wall is cleaned from bottom to top by the upwardly inclined jet flow. Regardless of the cleaning process of drilling down or drilling out, the cleaning nozzle located above continues to work, which can continuously reduce the adhesion of the return material to the inner tube and ensure the cleaning effect.

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] 1. The oil and gas wellbore cleaning tool combination and cleaning method provided by the present invention can simultaneously meet the cleaning requirements of the wellbore inner wall such as wax scale and the well bottom sand, and has good cleaning quality.

[0031] 2. During the cleaning operation, the jet flow on the end short section is switched by throwing the ball to achieve better inner wall cleaning or bottom cleaning effect, reduce the number of trips, improve construction efficiency, shorten the cycle and reduce operation costs.

[0032] 3. Reasonable arrangement of nozzle mounting holes B and C is conducive to ensuring the strength of the end short section and the middle short section, reducing the impact of the opening and extending the service life.

[0033] 4. The clever arrangement of the nozzle mounting hole C and the use of a rotatable cleaning nozzle can effectively avoid or reduce missed areas and further consolidate the cleaning effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 It is a schematic diagram of the end short section structure;

[0035] Figure 2 for Figure 1 Exploded diagram of

[0036] Figure 3 for Figure 1 A cross-sectional view of the slide sleeve (the liquid guide channel is in a conducting state);

[0037] Figure 4 for Figure 1 (the sliding sleeve fluid guide channel is in a blocked state);

[0038] Figure 5 It is a schematic diagram of the sliding sleeve structure;

[0039] Figure 6 It is a schematic diagram of the structure of the intermediate short section;

[0040] Figure 7 A cross-sectional view of an installation structure for a cleaning nozzle;

[0041] Figure 8 This is a schematic diagram of the distribution of nozzle mounting holes C;

[0042] Fig. 9 A perspective view of a cleaning nozzle;

[0043] Fig.10 It is a schematic diagram for assembling and using the present invention.

[0044] In the figure: 100, end short section; 110, nozzle mounting hole A; 111, main spray hole; 112, auxiliary spray hole;

[0045] 120, nozzle mounting hole B; 130, first short section; 131, upper guide channel; 132, pin hole;

[0046] 133, receiving chamber; 134, shear pin; 140, second short section; 141, lower guide channel;

[0047] 200, intermediate short section; 210, nozzle mounting hole C; 300, cleaning nozzle; 310, spiral water eye;

[0048] 400, sliding sleeve; 410, main body; 411, ball seat; 412, ring groove; 413, sealing groove;

[0049] 420, limiting part; 421, disc-shaped body; 422, petal-shaped body; 430, liquid guiding channel;

[0050] 500, steel ball; 600, bearing; 700, oil pipe string. DETAILED DESCRIPTION

[0051] The present invention is further described below in conjunction with embodiments and drawings.

[0052] refer to Figures 1 to 10The wellbore cleaning tool assembly shown in the figure mainly comprises an end short section 100 and a middle short section 200, both of which are hollow rotary tubular structures. Both ends of the end short section 100 and the middle short section 200 are open and have threaded joints, which can be quickly connected to the oil pipe for entering the well.

[0053] The bottom of the end short section 100 has a nozzle mounting hole A110 arranged downward (Note: the up and down directions in this application are based on its usage state, the end close to the bottom of the well is the bottom, and conversely, the end close to the wellhead is the top), and the side wall of the end short section 100 has a nozzle mounting hole B120, and the nozzle mounting holes B120 are evenly distributed along the circumference of the end short section 100. The nozzle mounting holes A110 and the nozzle mounting holes B120 are both connected to the inner cavity of the end short section 100, and are mainly used to install their respective matching nozzles to form a jet flow, thereby cleaning the wellbore.

[0054] The side wall of the middle short section 200 has a nozzle mounting hole C210 connected to the hollow inner cavity thereof, the nozzle mounting holes C210 are evenly distributed along the circumference of the middle short section 200, and the nozzle mounting hole C210 has a cleaning nozzle 300 installed in a rotatable manner, the cleaning nozzle 300 has at least three spiral water eyes 310, and the spiral water eyes 310 are evenly distributed along the axis of the cleaning nozzle 300.

[0055] Specific reference Figure 1 , Figure 3 and Figure 4 The lower end surface of the end short section 100 is generally spherical, and the nozzle mounting hole A110 includes a main spray hole 111 and N auxiliary spray holes 112, wherein the axis of the main spray hole 111 coincides with the axis of the end short section 100, and corresponds to the lowest position of the end surface of the end short section 100, and the N auxiliary spray holes 112 are evenly distributed on the circumferential outer side of the main spray hole 111 and are tilted outward, that is, the lower end of the auxiliary spray hole 112 is farther away from the axis of the end short section 100 than the upper end. In specific implementation, the angle between the axis of the auxiliary spray hole 112 and the axis of the end short section 100 is between 5° and 15°.

[0056] In another embodiment, in order to make the nozzle installed in the nozzle mounting hole A110 more suitable for sand blasting operations, the diameter of the main spray hole 111 is larger than the diameter of the auxiliary spray hole 112, so that the jet flow ejected through the nozzle in the main spray hole 111 has a greater relative impact force and flow rate, and can achieve a better sand blasting effect.

[0057] like Figure 1 and Figure 2 As shown, in this embodiment, the nozzle mounting holes B120 are staggered and evenly distributed along the axis of the end sub 100. Specifically, the nozzle mounting holes B120 are distributed in a sinusoidal shape on the end sub 100, and adjacent nozzle mounting holes B120 have fixed axial and circumferential spacings.

[0058] In the present application, in order to cooperate with the flushing effect in the nozzle mounting hole A110, the nozzle mounting hole B120 is inclined toward the upper end of the end short section 100, that is, the upper end of the nozzle mounting hole B120 is farther away from the axis of the end short section 100 relative to the lower end. Usually, the angle between the axis of the nozzle mounting hole B120 and the axis of the end short section 100 is between 20° and 50°, which can exert roughly opposite impact forces on the attachments on the inner wall of the wellbore, which is beneficial to improve the cleaning effect.

[0059] In another embodiment, in order to further improve the applicability of the tool and achieve a better bottom hole sand flushing effect or wellbore inner wall flushing effect, the end short section 100 is also used in conjunction with the sliding sleeve 400. Figures 2 to 5 As shown, the sliding sleeve 400 includes a tubular main body 410 and a limiting portion 420 formed at the lower end of the main body 410 , and a liquid guiding channel 430 is provided in the sliding sleeve 400 .

[0060] The end short section 100 is a split structure, mainly including a first short section 130 and a second short section 140 connected together in an upper and lower manner. In this embodiment, the first short section 130 and the second short section 140 are connected together through a threaded joint, and the nozzle mounting hole B120 and the nozzle mounting hole A110 are respectively located on the first short section 130 and the second short section 140. The first short section 130 has an upper guide channel 131 adapted to the main body 410, and the outer diameter of the limiting portion 420 is larger than the diameter of the upper guide channel 131. The second short section 140 has a lower guide channel 141 adapted to the limiting portion 420.

[0061] like Figure 2 , Figure 3 and Figure 5 As shown, the side wall of the first short section 130 is provided with a pin hole 132, and the upper side wall of the main body 410 is provided with an annular groove 412. In the initial state, the sliding sleeve 400 is installed in the first short section 130 through the shear pin 134. The shear pin passes through the pin hole 132 and then extends into the annular groove 412, which has an axial fixing effect on the sliding sleeve 400. The pin hole 132 is located above the nozzle mounting hole B120, and the main body 410 corresponds to the position of the nozzle mounting hole B120, thereby blocking the nozzle mounting hole B120. At this time, the fluid cannot be sprayed out through the nozzle of the nozzle mounting hole B120. A sealing groove 413 is provided on the main body 410 below the annular groove 412. During installation, a sealing ring is inserted to improve the sealing between it and the upper guide channel 131.

[0062] In order to further improve the installation effect of the sliding sleeve 400, a receiving cavity 133 adapted to the limiting portion 420 is provided near the lower end of the first short section 130. Figures 3 to 5As shown, the receiving cavity 133 is connected with the upper guide channel 131. When the sliding sleeve 400 is in the initial state, the limiting portion 420 can be completely received in the receiving cavity 133, which does not hinder the transportation or movement of the first short section 130, and the connection operation between the first short section 130 and the second short section 140, and avoids damage to the sliding sleeve 400. On this basis, the lower end of the first short section 130 in this embodiment adopts a male buckle structure, and the upper end of the second short section 140 adopts a female buckle structure, which can further avoid collision with the sliding sleeve 400 during the connection process.

[0063] like Figure 5 As shown, the limiting part 420 includes a disc-shaped body 421 and a petal-shaped body 422 evenly distributed at the bottom of the disc-shaped body 421. The disc-shaped body 421 is disc-shaped, and its diameter is substantially consistent with the diameter of the lower guide channel 141. The inner side of the upper end of the sliding sleeve 400 has a ball seat 411, which can be used for the steel ball 500 to be seated thereon. The ball seat 411 is an arc surface adapted to the steel ball 500 and blocks the liquid guide channel 430. In addition, in order to ensure the stability of the sliding sleeve 400, the petal-shaped bodies 422 in this embodiment are all arc-shaped block structures, and their outer sides can be well fitted with the lower guide channel 141.

[0064] In the above-mentioned embodiments, the cleaning nozzles 300 on the intermediate short section 200 are all rotatably mounted in the corresponding nozzle mounting holes C210, and the axis of the nozzle mounting hole C210 is perpendicular to the axis of the intermediate short section 200. Specifically, the structure of the cleaning nozzle 300 is generally as follows: Fig. 9 As shown, the appearance is similar to that of a conventional nozzle, but the difference is that there are at least three spiral water holes 310 inside. The spiral water holes 310 are spiral, but the corresponding number of spiral turns is less than 1, and they pass through both ends of the cleaning nozzle 300. The cleaning nozzle 300 is installed in the nozzle mounting hole C210 through a bearing 600, so that when water flows through the spiral water holes 310, it can drive the cleaning nozzle 300 to rotate as a whole, so that when it acts on the inner wall of the wellbore, it actually forms a surface impact, which has a larger coverage area than traditional point impact and can achieve a better impact effect.

[0065] In specific implementation, threaded fastening or interference fit can be used between the bearing 600 and the nozzle mounting hole C210, as well as between the cleaning nozzle 300 and the bearing 600. The nozzle mounting hole C210 can be set in a stepped hole shape. In conjunction with a special installation tool, the inner end diameter of the nozzle mounting hole C210 can be larger than the outer end diameter. In this way, the cleaning nozzle 300 is installed from the inside of the intermediate short section 200, which can improve the installation stability of the cleaning nozzle 300, facilitate replacement, and withstand greater pressure. In this case, both ends of the intermediate short section 200 are male buckles to avoid damage to the threads during disassembly and assembly.

[0066] Of course, you can also Figures 6 to 8The structure shown is set up in reverse, that is, installed from the outside, which is relatively easier to install the cleaning nozzle 300, but not particularly conducive to its disassembly and replacement.

[0067] Based on the cleaning nozzle 300 structure of this type, the flow area of ​​the spiral water eye 310 thereof gradually decreases from the inside to the outside along the radial direction of the middle short section 200, which can achieve a certain pressure-increasing effect.

[0068] In addition to the above structure, the cleaning nozzle 300 may also adopt a fan blade-like structure, which is supported in the nozzle mounting hole C210 by an axis, and the gap between adjacent blades is similar to the spiral water eye 310 structure. Similar structures are within the protection scope of this application.

[0069] In this application, in order to fully ensure the scouring coverage area and ensure the overall strength of the intermediate short section 200, the nozzle mounting holes C210 are evenly distributed in a spiral along the length direction of the intermediate short section 200. That is, all the nozzle mounting holes C210 are evenly spaced in the length direction and circumferential direction of the intermediate short section 200.

[0070] In this application, based on the above-mentioned oil and gas well wellbore cleaning tool combination, this application proposes a production oil and gas well wellbore cleaning method, which is mainly carried out in the following steps:

[0071] Step 1: Install nozzles of appropriate sizes in the nozzle mounting hole A110 and the nozzle mounting hole B120.

[0072] Step 2: Lower the end short section 100 through the tubing string 700 into the wellbore of the oil and gas well to be cleaned. During the drilling process, the tubing string is supplied with liquid through the ground liquid supply equipment, and the inner wall of the wellbore is cleaned from top to bottom by the jet flow of the nozzle in the nozzle mounting hole A110. The drilling is carried out while cleaning. In the specific implementation process, the tubing string can be a single tube of multiple tubings or a tubing column. Of course, continuous tubing operation can be used to further improve the operation efficiency.

[0073] Step 3: Observe the return of the wellhead annulus. If there is no wax return, connect the intermediate short section 200 to the tubing string. At this time, the drilling tool assembly structure is as follows: Fig.10 As shown, the drilling is continued to be cleaned, and while the lower part is cleaned, the jet flow of the cleaning nozzle 300 is used to perform a secondary cleaning on the upper inner cylinder wall.

[0074] Step 4: When the end sub 100 reaches the target layer, if sand flushing is required, rotate the pipe and increase the surface fluid supply for a period of time to perform sand flushing. After the wellhead annulus returns without sand sediment, put the steel ball 500 in. If sand flushing is not required, directly put the steel ball 500 in. Figure 4As shown, after the steel ball 500 is put into the liquid channel 430, because its diameter is larger than the diameter of the liquid guiding channel 430, it contacts and seals with the ball seat portion 411, thereby blocking the liquid guiding channel 430, increasing the surface liquid supply to destroy the shear pin, and the sleeve 400 moves downward, exposing the inner end of the nozzle mounting hole B120. At this time, the nozzle in the nozzle mounting hole A110 is blocked and no fluid is sprayed out. The jet flow of the nozzle in the nozzle mounting hole B120 is mainly used to clean the inner wall of the wellbore from bottom to top.

[0075] Step 5: Clean and pull out the pipe string at the same time to complete the cleaning operation. During the implementation process, control the speed of lowering and pulling out the pipe string according to the return situation at the wellhead to ensure that the cleaning effect is fully achieved.

[0076] In the specific implementation process, it can be selected whether to install the sliding sleeve 400 according to the needs. For example, if the main purpose of drilling is to clean the circumferential side wall of the inner tube, it is possible to choose not to install the sliding sleeve 400. If sand flushing and wax removal are required during drilling, the sliding sleeve 400 can be installed, and then in step 4, the jet direction is changed by throwing a ball to achieve a targeted cleaning effect. In addition, the first short section 130 and the second short section 140 can also be used separately.

[0077] The use of the oil and gas wellbore cleaning tool combination and cleaning method of the present application can meet various well repair needs of oil and gas wells, achieve better cleaning effects, improve cleaning efficiency, and relatively reduce operating costs.

[0078] Finally, it should be noted that the above description is only a preferred embodiment of the present invention. Under the guidance of the present invention, ordinary technicians in this field can make various similar expressions without violating the purpose and claims of the present invention, and such changes all fall within the scope of protection of the present invention.

Claims

1. A wellbore cleaning tool assembly for oil and gas production, characterized in that: The invention comprises an end short section (100) and an intermediate short section (200) both of which are hollow tubular structures, wherein both ends of the end short section (100) and the intermediate short section (200) are provided with threaded joints, wherein the bottom of the end short section (100) is provided with a nozzle mounting hole A (110) arranged downward, and the side wall of the end short section (100) is provided with a nozzle mounting hole B (120), and the nozzle mounting holes B (120) are evenly distributed along the circumference of the end short section (100); The nozzle mounting hole A (110) comprises N auxiliary spray holes (112), the N auxiliary spray holes (112) are arranged obliquely outward, and the nozzle mounting hole B (120) is arranged obliquely toward the upper end of the end short section (100); The side wall of the intermediate short section (200) has nozzle mounting holes C (210), the nozzle mounting holes C (210) are evenly distributed along the circumference of the intermediate short section (200), and a cleaning nozzle (300) is rotatably mounted in the nozzle mounting holes C (210), and the cleaning nozzle (300) has at least three spiral water holes (310).

2. The oil and gas wellbore cleaning tool assembly according to claim 1, characterized in that: The nozzle mounting hole A (110) further comprises a main spray hole (111), wherein the axis of the main spray hole (111) coincides with the axis of the end short section (100), and the N auxiliary spray holes (112) are evenly distributed on the circumferential outer side of the main spray hole (111) and are arranged to be inclined outward.

3. The oil and gas wellbore cleaning tool assembly according to claim 1 or 2, characterized in that: The nozzle mounting holes B (120) are staggered and evenly distributed along the axis of the end short section (100).

4. The oil and gas wellbore cleaning tool assembly according to claim 1 or 2, characterized in that: The sliding sleeve (400) comprises a hollow tubular main body (410) and a limiting portion (420) formed at one end of the main body (410); the sliding sleeve (400) has a liquid guide channel (430) therein; The end short section (100) comprises a first short section (130) and a second short section (140) which are connected in an integral manner from top to bottom, wherein the first short section (130) has an upper guide channel (131) adapted to the main body (410), the outer diameter of the limiting portion (420) is greater than the diameter of the upper guide channel (131), and the second short section (140) has a lower guide channel (141) adapted to the limiting portion (420); In the initial state, the sliding sleeve (400) is installed in the first short section (130) via a shear pin, and the main body (410) corresponds to the position of the nozzle mounting hole B (120) and blocks the nozzle mounting hole B (120).

5. The oil and gas wellbore cleaning tool assembly according to claim 4, characterized in that: The limiting portion (420) comprises a disc-shaped body (421) and petal-shaped bodies (422) evenly distributed at the bottom of the disc-shaped body (421).

6. The oil and gas wellbore cleaning tool assembly according to claim 2, characterized in that: The diameter of the main spray hole (111) is greater than the diameter of the auxiliary spray hole (112).

7. The oil and gas wellbore cleaning tool assembly according to claim 1, characterized in that: The flow area of ​​the spiral water eye (310) gradually decreases from the inside to the outside along the radial direction of the middle short section (200).

8. The oil and gas wellbore cleaning tool assembly according to claim 1 or 2, characterized in that: The nozzle mounting holes C (210) are evenly distributed in a spiral line along the length direction of the middle short section (200).

9. A method for cleaning a wellbore of an oil and gas production well, characterized in that: The oil and gas wellbore cleaning tool assembly as claimed in claim 4 or 5 is used and the following steps are performed: S1: installing each adaptive nozzle in the nozzle mounting hole A (110) and the nozzle mounting hole B (120); S2: lowering the end short section (100) through the oil pipe string into the wellbore of the oil and gas production well to be cleaned. During the drilling process, the oil pipe string is supplied with liquid through the surface liquid supply equipment, and the inner wall of the wellbore is cleaned from top to bottom by the jet flow of the nozzle in the nozzle installation hole A (110); S3: Observe the return of the wellhead annulus. If there is no return of wax, connect the intermediate short joint (200) to the oil pipe string, and then continue to drill down for cleaning. While cleaning the lower part, use the jet flow of the cleaning nozzle (300) to clean the upper inner cylinder wall for a second time; S4: When the end short section (100) reaches the target layer, if sand flushing is required, the pipe is rotated and the surface fluid supply is increased for a period of time to perform sand flushing. After the wellhead annulus is free of sand, a steel ball (500) is inserted; If sand flushing is not required, a steel ball (500) is directly inserted, wherein the diameter of the steel ball (500) is larger than the diameter of the liquid guide channel (430), and the steel ball (500) blocks the liquid guide channel (430), thereby increasing the surface liquid supply to damage the shear pin, and the sliding sleeve (400) moves downward, and the inner end of the nozzle mounting hole B (120) is exposed, and the inner wall of the wellbore is cleaned from bottom to top using the jet flow of the nozzle in the nozzle mounting hole B (120); S4: Pull out the pipe string and end the cleaning operation.

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