Centrifugal rotational flow sand washing well washing tool and well washing method

Abstract

The invention belongs to the technical field of oilfield sand production well treatment, and particularly relates to a centrifugal rotational flow sand washing well washing tool and a well washing method. The centrifugal rotational flow sand-washing well-washing tool comprises an upper connector, a righting mechanism, a sleeve, a locking cap, a centrifugal nozzle head and a rotating shaft cylinder. During well washing, the centrifugal rotational flow sand washing well washing tool is connected through a conventional tool oil pipe and then is put into a well, sand washing liquid is pumped into the tool oil pipe after the sand surface is detected, and after the sand washing liquid descends to the centrifugal nozzle head from the tool oil pipe, driving force is generated when the sand washing liquid is sprayed out from the side face water spraying opening to drive the centrifugal nozzle head and the rotating shaft to rotate at a high speed; the high-energy jet flow sprayed out of the side face water spraying opening can effectively clean sand, sand scale cementation blocks and the like accumulated on the wall of the casing pipe, and the high-energy jet flow sprayed out of the bottom water spraying opening can crush sand bridges formed in the casing pipe in an accumulated mode. The sand washing speed is increased, the well occupation period of sand washing measures is effectively shortened, and meanwhile the operation cost is reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of oilfield sand-producing well management, and in particular relates to a centrifugal cyclone sand flushing and well washing tool and a well washing method. Background Art

[0002] For the development of low permeability reservoirs, fracturing is currently a commonly used means of transformation. With the continuous advancement of fracturing technology, the number of fracturing stages is increasing, and the amount of fracturing sand used is also increasing. With the production of oil wells, part of the fracturing sand enters the casing through the blasthole driven by the formation fluid flow, and the composition of the formation fluid is complex, and the sand and scaling problems often appear intertwined. Some quartz sand and scale are cemented to form sand-scale cement blocks. Loose quartz sand and sand-scale cement blocks accumulate near the blasthole and even form sand bridges, blocking the oil flow channel, seriously affecting the oil well production capacity. Sand flushing measures need to be taken to clean the wellbore and restore the oil well production capacity. At present, the inclined tip is widely used in sand flushing measures as a commonly used sand flushing tool, such as the utility model patent with application number CN201520356976.2 and the name of the utility model patent for anti-stuck inclined tip of sand flushing pipe column in casing damaged wells. The manufacturing process of the inclined tip is simple and low-cost, but it is not effective in treating sand, scale and cement blocks. It usually requires a grinding drill to be used for treatment, which increases the number of drilling times, construction costs, and the construction period of the well, affecting production timeliness. Summary of the invention

[0003] The present invention provides a centrifugal cyclone sand flushing well washing tool and a well washing method, the purpose of which is to provide a device and a method that can quickly and effectively clean the sand on the casing wall and the sand bridges and sand scale cemented blocks formed by accumulation in the casing, so as to efficiently clean the wellbore and restore the oil well production capacity.

[0004] To achieve the above object, the technical solution adopted by the present invention is: A centrifugal cyclone sand flushing and well washing tool comprises an upper joint, a straightening mechanism, a sleeve, a locking cap, a centrifugal nozzle head and a rotating shaft cylinder; the upper joint is connected to the upper port of the sleeve through the straightening mechanism; the rotating shaft cylinder is rotatably connected in the sleeve through a rotating mechanism, the top end of the rotating shaft cylinder is connected to the straightening mechanism, the bottom end of the rotating shaft cylinder extends outside the sleeve and is connected to the centrifugal nozzle head; an inclined water spray port is provided on the side wall of the centrifugal nozzle head; the locking cap is sealingly sleeved on the outer side wall of the rotating shaft cylinder and is connected to the inner side wall of the bottom end of the sleeve.

[0005] The straightening mechanism includes a plurality of straightening blocks, a straightening seat and a plurality of return springs; the plurality of straightening blocks are vertically and evenly arranged around the straightening seat, and a plurality of return springs are horizontally connected between each straightening block and the straightening seat; the upper end of the straightening seat is connected to the inner side wall of the lower end of the upper joint, and the lower end of the straightening seat is connected to the inner side wall of the upper end of the sleeve; the upper end of the straightening block contacts the inner side wall of the lower end of the upper joint, and the lower end of the straightening block contacts the inner side wall of the upper end of the sleeve.

[0006] The straightening seat is a circular structure, and a second groove for accommodating a reset spring is provided in the middle of its outer wall, and threads are provided on the outer walls of the upper and lower ends of the straightening seat respectively; the straightening block is a long strip, and a plurality of first grooves for placing the reset spring are opened in the middle of its inner side, and inwardly inclined inclined surfaces are symmetrically provided on the outer sides of its upper and lower ends, and shoulders are provided on the outer walls of the two end ends of the straightening block.

[0007] The sleeve is a circular ring-shaped structure; an annular protrusion is arranged on the upper part of the inner wall of the sleeve, and a plurality of annular grooves are arranged on the inner wall of the protrusion, and an upper sealing ring is placed in each annular groove; shoulders are arranged on the inner walls of the upper and lower ends of the sleeve; a thread is arranged on the inner wall of the sleeve between the upper shoulder and the top of the protrusion, and a thread is arranged on the inner wall of the lower shoulder.

[0008] The rotating mechanism includes an upper bearing, a lower bearing pressure ring, a lower bearing and an upper bearing pressure ring; the upper part of the rotating shaft cylinder is connected to the upper inner wall of the sleeve through the upper bearing, and the upper bearing pressure ring is connected between the top of the upper bearing and the sleeve; the lower part of the rotating shaft cylinder is connected to the lower inner wall of the sleeve through the lower bearing, and the lower bearing pressure ring is connected between the bottom of the lower bearing and the sleeve and the locking cap.

[0009] The centrifugal nozzle head is an integrated structure consisting of a hollow cylinder with upper and lower openings and a hollow truncated cone with an upper open end and a larger upper part and a smaller lower part; the inner diameters of the cylinder and the truncated cone are the same, and the outer diameter of the cylinder is the same as the diameter of the upper bottom surface of the truncated cone; a plurality of side water spray outlets with an inner high and an outer low inclined arrangement are symmetrically opened on the side wall of the truncated cone, and a bottom water spray outlet penetrating the bottom surface is opened on the bottom surface of the truncated cone.

[0010] The side water spray outlets are provided with four.

[0011] The downward direction of the axis line of each side water spray outlet forms an angle of 30-50° with the downward direction of the central axis line of the centrifugal nozzle head, and the axis line of each water spray outlet forms an angle of 30-50° with the connecting line of the outlets of the two adjacent water spray outlets on the inner side of the side wall.

[0012] The rotating shaft cylinder is a circular cylindrical structure, and an annular protrusion is arranged on its outer wall; a shoulder is arranged on the lower outer wall of the rotating shaft cylinder, and a thread connected to the centrifugal nozzle head is arranged on the side wall of the shoulder.

[0013] A well washing method using a centrifugal cyclone sand flushing well washing tool, using the centrifugal cyclone sand flushing well washing tool, comprising the following steps: Step 1: Connect the upper joint of the centrifugal cyclone sand flushing and well washing tool to the tool oil pipe and lower it into the well; Step 2: After the sand surface is detected at the bottom of the centrifugal cyclone sand flushing and well washing tool, the sand flushing liquid is pumped into the tool oil pipe. The sand flushing liquid flows downward through the tool oil pipe and enters the centrifugal nozzle head in sequence through the straightening mechanism and the rotating shaft cylinder; Step 3: When the sand flushing liquid passes through the side water spraying port inclined on the centrifugal nozzle head, the centrifugal nozzle head and the rotating shaft are driven to rotate at high speed due to the strong jet force of the sand flushing liquid, and the high-energy jet sprayed from the side water spraying port continuously impacts the oil well casing, and the accumulated sand and sand scale cement blocks on the oil well casing wall are removed after being impacted; the high-energy jet sprayed from the bottom water spraying port will impact the sand bridge accumulated in the casing to break it; Step 4: After the well washing is completed, stop pumping the sand flushing fluid and remove the centrifugal cyclone sand flushing and well washing tool from the well.

[0014] Beneficial effects: (1) The centrifugal nozzle head in the present invention can rotate at high speed driven by the sand flushing liquid, and the high-energy jet generated can quickly and effectively clean the sand on the casing wall and the sand bridges, sand scale cement blocks, etc. formed by the accumulation in the casing, thereby solving the problem that the conventional inclined tip frequently encounters obstacles and slows the advance during the sand flushing process, improving the sand flushing speed, effectively reducing the sand flushing measures and the well cycle, and at the same time reducing the operating cost, providing a new and efficient cleaning tool for the treatment of sand producing wells.

[0015] (2) In the present invention, an inclined side water spray port is arranged on the centrifugal nozzle head, so that the rotating shaft cylinder can rotate at high speed, thereby driving the centrifugal nozzle head to rotate at high speed, so that the casing wall can be cleaned more thoroughly.

[0016] (3) The centrifugal nozzle head of the present invention is provided with side water spray ports and bottom water spray ports, which can clean the casing wall in all directions.

[0017] (4) The design of the angle formed by the downward direction of the axis of the side water spray outlet on the centrifugal nozzle head and the downward direction of the central axis of the centrifugal nozzle head at 45° makes the rotation speed of the centrifugal nozzle head the fastest, and the high-energy jet ejected has the best effect in cleaning the sand on the casing wall and the sand scale agglomerates accumulated in the casing.

[0018] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention and implement it according to the contents of the specification, the following is a detailed description of the preferred embodiments of the present invention in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0020] Figure 1 It is a structural cross-sectional view of the present invention.

[0021] Figure 2 It is a partial cross-sectional view of the centrifugal nozzle head of the present invention after being cut along the plane where the axis line of one of the water spray outlets is located.

[0022] Figure 3 It is a top view of the centrifugal nozzle head of the present invention after being cut along the conical surface where the axis lines of the four water spray outlets are located.

[0023] Figure 4 It is a cross-sectional view of the righting seat in the present invention.

[0024] Figure 5 It is a cross-sectional view of the straightening block in the present invention.

[0025] Figure 6 It is a cross-sectional view of the sleeve in the present invention.

[0026] Figure 7 It is a cross-sectional view of the rotating shaft cylinder in the present invention.

[0027] In the figure: 1, upper joint; 2, straightening block; 3, straightening seat; 4, upper sealing ring; 5, upper bearing; 6, sleeve; 7, locking cap; 8, centrifugal nozzle head; 9, side water spray port; 10, bottom water spray port; 11, lower sealing ring; 12, lower bearing pressure ring; 13, lower bearing; 14, rotating shaft cylinder; 15, upper bearing pressure ring; 16, reset spring; 17, protrusion; 18, first groove; 19, second groove. DETAILED DESCRIPTION

[0028] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] Embodiment 1: according to Figure 1-Figure 7 A centrifugal cyclone sand flushing and well washing tool shown in the figure comprises an upper joint 1, a straightening mechanism, a sleeve 6, a locking cap 7, a centrifugal nozzle head 8 and a rotating shaft cylinder 14; the upper joint 1 is connected to the upper port of the sleeve 6 through the straightening mechanism; the rotating shaft cylinder 14 is rotatably connected in the sleeve 6 through a rotating mechanism, the top end of the rotating shaft cylinder 14 is connected to the straightening mechanism, the bottom end of the rotating shaft cylinder 14 extends to the outside of the sleeve 6 and is connected to the centrifugal nozzle head 8; an inclined water spray port is provided on the side wall of the centrifugal nozzle head 8; the locking cap 7 is sealingly sleeved on the outer side wall of the rotating shaft cylinder 14 and is connected to the inner side wall of the bottom end of the sleeve 6.

[0030] In actual use, firstly, the upper joint 1 in the centrifugal cyclone sand flushing and well washing tool is connected to the tool oil pipe and lowered into the well; after the sand surface is detected at the bottom end of the centrifugal cyclone sand flushing and well washing tool, a sand flushing liquid is pumped into the tool oil pipe, and the sand flushing liquid flows downward from the tool oil pipe, and enters the centrifugal nozzle head 8 through the straightening mechanism and the rotating shaft cylinder 14 in sequence; when the sand flushing liquid passes through the side water spraying port 9 obliquely arranged on the centrifugal nozzle head 8, due to the strong jet force of the sand flushing liquid, the centrifugal nozzle head 8 and the rotating shaft are driven to rotate at a high speed, and the high-energy jet sprayed from the side water spraying port 9 continuously impacts the oil well casing, and the accumulated sand and sand scale cemented blocks on the oil well casing wall are removed after being impacted; after the well washing is completed, the pumping of the sand flushing liquid is stopped, and the centrifugal cyclone sand flushing and well washing tool is taken out of the well.

[0031] The present invention solves the problem in the prior art that the inclined tip frequently encounters obstructions and slows down the progress during the sand flushing process, improves the sand flushing speed, effectively reduces the well cycle occupied by the sand flushing measures, and at the same time reduces the operating cost, providing a new and efficient cleaning tool for the management of sand producing wells.

[0032] Embodiment 2: according to Figure 1 , Figure 4 and Figure 5 A centrifugal cyclone sand flushing and well washing tool shown in the figure is different from the embodiment 1 in that: the straightening mechanism includes a plurality of straightening blocks 2, a straightening seat 3 and a plurality of return springs 16; the plurality of straightening blocks 2 are vertically and evenly arranged around the straightening seat 3, and a plurality of return springs 16 are horizontally connected between each straightening block 2 and the straightening seat 3; the upper end of the straightening seat 3 is connected to the inner side wall of the lower end of the upper joint 1, and the lower end of the straightening seat 3 is connected to the inner side wall of the upper end of the sleeve 6; the upper end of the straightening block 2 contacts the inner side wall of the lower end of the upper joint 1, and the lower end of the straightening block 2 contacts the inner side wall of the upper end of the sleeve 6.

[0033] In actual use, the function of the righting mechanism is to keep the centrifugal cyclone sand flushing and well washing tool and the axis line of the oil well casing in the same line during the process of going down into the well and flushing and washing the well.

[0034] In this embodiment, six straightening blocks 2 are provided. In specific applications, the number of straightening blocks 2 provided can be determined according to actual needs to ensure that the straightening blocks 2 can stably contact with the casing wall.

[0035] During the process of going down into the well, under the action of the return spring 16, the straightening block 2 always keeps in contact with the inner wall of the oil well casing even if the inner diameter of the oil well casing changes, thereby ensuring the smooth progress of the sand flushing and well washing process.

[0036] Embodiment three: according to Figure 1 , Figure 4 and Figure 5 The centrifugal cyclone sand flushing and well washing tool shown in the figure is different from the second embodiment in that: the straightening seat 3 is a circular ring structure, and a second groove 19 for accommodating a reset spring 16 is provided in the middle of its outer wall, and threads are provided on the outer walls of the upper and lower ends of the straightening seat 3 respectively; the straightening block 2 is a long strip, and a plurality of first grooves 18 for placing the reset spring 16 are opened in the middle of its inner side, and inwardly inclined inclined surfaces are symmetrically provided on the outer sides of the upper and lower ends, and shoulders are provided on the outer walls of the ends of the straightening block 2.

[0037] In actual use, the straightening seat 3 adopts the above technical solution, which can not only conveniently connect the upper joint 1 with the sleeve 6, but also play a better straightening role.

[0038] The inwardly inclined slopes symmetrically arranged on the outer sides of the upper and lower ends of the straightening block 2 facilitate the displacement of the straightening block 2 relative to the inner wall of the bottom end of the upper joint 1 and the inner wall of the top end of the sleeve 6 when the reset spring 16 is compressed or reset.

[0039] Embodiment 4: according to Figure 1 and Figure 6 The centrifugal cyclone sand flushing and well washing tool shown in the figure is different from the embodiment 1 in that: the sleeve 6 is a circular ring structure; an annular protrusion 17 is provided on the upper part of the inner wall of the sleeve 6, and a plurality of annular grooves are provided on the inner wall of the protrusion 17, and an upper sealing ring 4 is placed in each annular groove; shoulders are provided on the inner walls of the upper and lower ends of the sleeve 6; a thread is provided on the inner wall of the sleeve 6 between the upper shoulder and the top of the protrusion 17, and a thread is provided on the inner wall of the lower shoulder.

[0040] In actual use, the rotating shaft cylinder 14 is rotatably connected to the inside of the sleeve 6 through the rotating mechanism, the lower surface of the annular protrusion 17 is connected to the rotating shaft cylinder 14 through the upper bearing 5 in the rotating mechanism, and the upper part of the rotating shaft cylinder 14 is sealed to the inner side wall of the annular protrusion 17; the lower part of the rotating shaft cylinder 14 is connected to the inner side wall of the lower part of the sleeve 6 through the lower bearing 13 in the rotating mechanism. The thread provided on the inner side wall of the sleeve 6 between the upper end shoulder and the top of the protrusion 17 is used for connection with the straightening seat 3, the bottom end of the straightening block 2 is in contact with the inner side wall of the upper end shoulder of the sleeve 6, and the thread on the inner side wall of the lower end shoulder is used for connection with the locking cap 7.

[0041] Embodiment five: according to Figure 1 The centrifugal cyclone sand flushing and well washing tool shown in the figure is different from the embodiment 1 in that: the rotating mechanism includes an upper bearing 5, a lower bearing pressure ring 12, a lower bearing 13 and an upper bearing pressure ring 15; the upper part of the rotating shaft cylinder 14 is connected to the upper inner wall of the sleeve 6 through the upper bearing 5, and the upper bearing pressure ring 15 is connected between the top of the upper bearing 5 and the sleeve 6; the lower part of the rotating shaft cylinder 14 is connected to the lower inner wall of the sleeve 6 through the lower bearing 13, and the lower bearing pressure ring 12 is connected between the bottom of the lower bearing 13 and the sleeve 6 and the locking cap 7.

[0042] In actual use, the setting of the rotating mechanism ensures that the well washing fluid is flushed into the centrifugal nozzle head 8, and the well washing fluid generates high-speed rotation after passing through the side water spraying port 9 inclined on the centrifugal nozzle head 8, thereby efficiently cleaning the inner wall of the oil well casing.

[0043] The present invention provides a lower sealing ring 11 between the rotating shaft cylinder 14 and the locking cap 7, thereby ensuring the well washing effect of the present invention.

[0044] Embodiment six: according to Figure 1-Figure 3 The centrifugal cyclone sand flushing and well washing tool shown in the figure is different from the embodiment 1 in that: the centrifugal nozzle head 8 is an integrated structure consisting of a hollow cylinder with open top and bottom and a hollow frustum with open top and large top and small bottom; the inner diameters of the cylinder and the frustum are the same, and the outer diameter of the cylinder is the same as the diameter of the upper bottom surface of the frustum; a plurality of side water spray outlets 9 with inner high and outer low inclined settings are symmetrically opened on the side wall of the frustum, and a bottom water spray outlet 10 penetrating the bottom surface is opened on the bottom surface of the frustum.

[0045] Furthermore, four side water spray outlets 9 are provided.

[0046] Furthermore, the downward direction of the axis of each of the side water spray outlets 9 forms an angle of 45° with the downward direction of the central axis of the centrifugal nozzle head 8, and the axis of each water spray outlet 9 forms a 45° angle with the line connecting the outlets of the two adjacent water spray outlets 9 on the inner side of the side wall.

[0047] In actual use, the number of the side water spray ports 9 can be set according to the number of underground ports required.

[0048] In this embodiment, four side water spray ports 9 are provided, which can ensure efficient sand flushing and well washing tasks, and will not affect the strength of the centrifugal nozzle head 8.

[0049] The angle formed by the downward direction of the axis of the side water spray port 9 and the downward direction of the central axis of the centrifugal nozzle head 8 is designed to be 45°, which can optimize the high-speed rotation of the centrifugal nozzle head 8, so that the high-energy jet can best clean the sand on the casing wall and the sand and scale aggregates accumulated in the casing.

[0050] In specific applications, the angle formed by the axis of the water spray port 9 and the connecting line of the outlets of the two adjacent water spray ports 9 on the inner side of the side wall, and the angle formed by the downward direction of the axis of the side water spray port 9 and the downward direction of the central axis of the centrifugal nozzle head 8 can be selected according to actual needs. In this embodiment, different angles such as 30°, 35°, 40°, 45°, and 50° were used in the test, and the application effect was good.

[0051] A bottom water spray port 10 is designed to penetrate the bottom surface of the truncated cone body, so that high-energy jet well washing fluid can be sprayed out from the bottom to break the sand bridge accumulated in the casing, thereby achieving a better sand flushing and well washing effect of the present invention.

[0052] Embodiment seven: according to Figure 1 and Figure 7 The centrifugal cyclone sand flushing and well washing tool shown in the figure is different from the embodiment 1 in that: the rotating shaft cylinder 14 is a circular cylindrical structure, and a circular ring-shaped protrusion is provided on its outer wall; a shoulder is provided on the lower outer wall of the rotating shaft cylinder 14, and a thread connected to the centrifugal nozzle head 8 is provided on the side wall of the shoulder.

[0053] In actual use, the rotating shaft cylinder 14 is connected to the upper bearing 5 and the lower bearing 13 on the upper and lower surfaces of the annular protrusion respectively, and plays a role of limiting the upper bearing 5 and the lower bearing 13.

[0054] The lower part of the rotating shaft cylinder 14 is sealedly connected to the sleeve 6 through the locking cap 7, and the lower bearing 13 is fixed and limited.

[0055] The above technical solution can ensure that the components can be rotatably connected through the rotating mechanism and that the stability of the connection between the components can be ensured.

[0056] Embodiment eight: Reference Figure 1-Figure 7 A well washing method using a centrifugal cyclone sand flushing well washing tool, using the centrifugal cyclone sand flushing well washing tool, comprising the following steps: Step 1: Connect the upper connector 1 in the centrifugal cyclone sand flushing and well washing tool to the tool oil pipe and lower it into the well; Step 2: After the sand surface is detected at the bottom of the centrifugal cyclone sand flushing and well washing tool, a sand flushing liquid is pumped into the tool oil pipe. The sand flushing liquid flows downward through the tool oil pipe and enters the centrifugal nozzle head 8 through the straightening mechanism and the rotating shaft cylinder 14 in sequence; Step 3: When the sand flushing liquid passes through the side water spraying port 9 obliquely arranged on the centrifugal nozzle head 8, the centrifugal nozzle head 8 and the rotating shaft are driven to rotate at a high speed due to the strong jetting force of the sand flushing liquid, and the high-energy jet sprayed from the side water spraying port 9 continuously impacts the oil well casing, and the accumulated sand and sand scale cement blocks on the oil well casing wall are removed after being impacted; the high-energy jet sprayed from the bottom water spraying port 10 impacts the sand bridge accumulated in the casing to break it; Step 4: After the well washing is completed, stop pumping the sand flushing fluid and remove the centrifugal cyclone sand flushing and well washing tool from the well.

[0057] In actual use, the centrifugal nozzle head 8 of the present invention can rotate at high speed driven by the sand flushing liquid, and the generated high-energy jet can quickly and effectively clean the sand on the casing wall and the sand bridges, sand scale cement blocks, etc. formed by the accumulation in the casing, thereby solving the problem that the conventional inclined tip frequently encounters obstacles and slows the advancement during the sand flushing process, improving the sand flushing speed, effectively reducing the well cycle occupied by the sand flushing measures, and at the same time reducing the operating cost, providing a new and efficient cleaning tool for the management of sand producing wells.

[0058] In the present invention, the inclined side water spraying port is arranged on the centrifugal nozzle head, so that the rotating shaft cylinder can rotate at high speed, thereby driving the centrifugal nozzle head to rotate at high speed, so that the sleeve wall can be cleaned more thoroughly.

[0059] The centrifugal nozzle head of the present invention is provided with side water spraying ports and bottom water spraying ports, which can clean the casing wall in all directions.

[0060] In the absence of conflicts, technicians in this field can combine the relevant technical features in the above examples according to actual conditions to achieve corresponding technical effects. The specific combinations are not described here one by one.

[0061] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0062] In addition, the descriptions of "first", "second", etc. in the present invention are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" or "second" may explicitly or implicitly include at least one of the features.

[0063] The above are only preferred embodiments of the present invention. The present invention will not be limited to the embodiments shown herein, but should conform to the widest scope consistent with the principles and novel features disclosed herein. Any simple modification, equivalent changes and modifications made to the above embodiments according to the technical essence of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A centrifugal cyclone sand flushing and well washing tool, characterized in that: The invention comprises an upper joint (1), a straightening mechanism, a sleeve (6), a locking cap (7), a centrifugal nozzle head (8) and a rotating shaft cylinder (14); the upper joint (1) is connected to the upper end of the sleeve (6) through the straightening mechanism; the rotating shaft cylinder (14) is rotatably connected to the sleeve (6) through the rotating mechanism, the top end of the rotating shaft cylinder (14) is connected to the straightening mechanism, the bottom end of the rotating shaft cylinder (14) extends outside the sleeve (6) and is connected to the centrifugal nozzle head (8); an inclined water spraying port is arranged on the side wall of the centrifugal nozzle head (8); the locking cap (7) is sealingly sleeved on the outer side wall of the rotating shaft cylinder (14) and is connected to the inner side wall of the bottom end of the sleeve (6).

2. A centrifugal cyclone sand flushing and well washing tool as claimed in claim 1, characterized in that: The straightening mechanism comprises a plurality of straightening blocks (2), a straightening seat (3) and a plurality of return springs (16); the plurality of straightening blocks (2) are vertically and evenly arranged around the straightening seat (3), and a plurality of return springs (16) are horizontally connected between each straightening block (2) and the straightening seat (3); the upper end of the straightening seat (3) is connected to the inner side wall of the lower end of the upper joint (1), and the lower end of the straightening seat (3) is connected to the inner side wall of the upper end of the sleeve (6); the upper end of the straightening block (2) contacts the inner side wall of the lower end of the upper joint (1), and the lower end of the straightening block (2) contacts the inner side wall of the upper end of the sleeve (6).

3. A centrifugal cyclone sand flushing and well washing tool as claimed in claim 2, characterized in that: The straightening seat (3) is a circular ring structure, and a second groove (19) for accommodating a reset spring (16) is provided in the middle of its outer wall, and threads are provided on the outer walls of the upper and lower ends of the straightening seat (3). The straightening block (2) is a long strip, and a plurality of first grooves (18) for accommodating the reset spring (16) are provided in the middle of its inner side, and inwardly inclined inclined surfaces are symmetrically provided on the outer sides of its upper and lower ends, and shoulders are provided on the outer walls of the two end heads of the straightening block (2).

4. A centrifugal cyclone sand flushing and well washing tool as claimed in claim 1, characterized in that: The sleeve (6) is a circular ring-shaped structure; an annular protrusion (17) is provided on the upper part of the inner wall of the sleeve (6); a plurality of annular grooves are provided on the inner wall of the protrusion (17), and an upper sealing ring (4) is placed in each annular groove; shoulders are provided on the inner walls of the upper and lower ends of the sleeve (6); a thread is provided on the inner wall of the sleeve (6) between the upper shoulder and the top of the protrusion (17), and a thread is provided on the inner wall of the lower shoulder.

5. A centrifugal cyclone sand flushing and well washing tool as claimed in claim 1, characterized in that: The rotating mechanism comprises an upper bearing (5), a lower bearing pressure ring (12), a lower bearing (13) and an upper bearing pressure ring (15); the upper part of the rotating shaft cylinder (14) is connected to the upper inner wall of the sleeve (6) through the upper bearing (5), and the upper bearing pressure ring (15) is connected between the top of the upper bearing (5) and the sleeve (6); the lower part of the rotating shaft cylinder (14) is connected to the lower inner wall of the sleeve (6) through the lower bearing (13), and the lower bearing pressure ring (12) is connected between the bottom of the lower bearing (13) and the sleeve (6) and the locking cap (7).

6. A centrifugal cyclone sand flushing and well washing tool as claimed in claim 1, characterized in that: The centrifugal nozzle head (8) is an integrated structure consisting of a hollow cylinder with upper and lower openings and a hollow truncated cone with an upper opening and a larger upper part and a smaller lower part; the inner diameters of the cylinder and the truncated cone are the same, and the outer diameter of the cylinder is the same as the diameter of the upper bottom surface of the truncated cone; a plurality of side water spray outlets (9) with an inner high and an outer low inclined arrangement are symmetrically opened on the side wall of the truncated cone, and a bottom water spray outlet (10) penetrating the bottom surface is opened on the bottom surface of the truncated cone.

7. A centrifugal cyclone sand flushing and well washing tool as claimed in claim 6, characterized in that: Four side water spray ports (9) are provided.

8. A centrifugal cyclone sand flushing and well washing tool as claimed in claim 6 or 7, characterized in that: The downward direction of the axis of each of the side water spray outlets (9) forms an angle of 30-50° with the downward direction of the central axis of the centrifugal nozzle head (8), and the axis of each water spray outlet (9) forms an angle of 30-50° with the connecting line of the outlets of the two adjacent water spray outlets (9) on the inner side of the side wall.

9. A centrifugal cyclone sand flushing and well washing tool as claimed in claim 1, characterized in that: The rotating shaft cylinder (14) is a circular cylindrical structure, and a circular ring-shaped protrusion is arranged on its outer wall; a shoulder is arranged on the lower outer wall of the rotating shaft cylinder (14), and a thread connected to the centrifugal nozzle head (8) is arranged on the side wall of the shoulder.

10. A well washing method using a centrifugal cyclone sand flushing well washing tool, characterized in that: The centrifugal cyclone sand flushing and well washing tool as claimed in any one of claims 1 to 9 comprises the following steps: Step 1: Connect the upper joint (1) of the centrifugal cyclone sand flushing and well washing tool to the tool oil pipe and lower it into the well; Step 2: After the bottom end of the centrifugal cyclone sand flushing and well washing tool detects the sand surface, a sand flushing liquid is pumped into the tool oil pipe. The sand flushing liquid flows downward through the tool oil pipe and sequentially passes through the straightening mechanism and the rotating shaft cylinder (14) into the centrifugal nozzle head (8); Step 3: When the sand flushing liquid passes through the side water spraying port (9) obliquely arranged on the centrifugal nozzle head (8), the centrifugal nozzle head (8) and the rotating shaft are driven to rotate at a high speed due to the strong spraying force of the sand flushing liquid, and the high-energy jet sprayed from the side water spraying port (9) continuously impacts the oil well casing, and the sand and sand scale cement blocks accumulated on the oil well casing wall are removed after being impacted; the high-energy jet sprayed from the bottom water spraying port (10) impacts the sand bridge accumulated in the casing to break it; Step 4: After the well washing is completed, stop pumping the sand flushing fluid and remove the centrifugal cyclone sand flushing and well washing tool from the well.

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