High-efficiency cyclone milling and sand washing device for horizontal well and sand washing method

Abstract

The application discloses a horizontal well high-efficiency cyclone grinding and milling sand washer, which comprises an outer spiral sand washer body, an inner spiral sand washer body, a core pipe, an upper joint and a core shaft, the outer spiral sand washer body is provided with an axial nozzle, an axial nozzle pressure cap and a spiral flow guide groove a, and the inner spiral sand washer body is provided with a spiral flow guide groove b. The application can autonomously generate rotary power, and has the tangential scouring function of the cyclone sand washing tool and the grinding and milling function of the screw power drilling tool. The application further discloses a horizontal well high-efficiency cyclone grinding and milling sand washing method. Specifically, the sand washer is assembled, the sand washing pipe column is connected, the sand washing pipe column is lowered into the casing, the downhole sand scale position is explored, the wellhead oil pipe is connected with the sand washing pump truck, the pump is started to perform the sand washing and grinding and milling operation, the sand washing liquid enters the core pipe inner cavity from the oil pipe through the centralizer and then enters the core pipe inner cavity from the sand washer upper joint inner cavity, thereby providing the sand washer with three-stage forward rotary power and rotary grinding and milling power, and sand washing is realized.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of oil and gas exploration and development, and relates to a horizontal well high-efficiency rotational flow milling sand washer and a horizontal well high-efficiency rotational flow milling sand washing method. BACKGROUND

[0002] After oil and gas and water wells are produced for a period of time, problems such as sand production, scaling, perforation hole blockage and wellbore bridging may occur, and scale milling, sand washing and plugging removal and other wellbore cleaning measures must be taken. The existing sand washing tools are relatively simple, the simplest being a beveled tip, which can only bring downhole sand and gravel out of the wellbore by using a well flushing fluid, and cannot handle wellbore scaling and perforation hole blockage problems. The relatively advanced sand washing tool is a sand washer with a jet nozzle, which converts pressure potential energy into high-speed jet kinetic energy, and the sand washing head is designed with multiple directional nozzles for washing sand and scale at different angles, especially the lateral nozzles, which have a significant cleaning and plugging removal effect on the wellbore and perforation holes, and can impact and break up relatively loose scale blocks and cemented materials, but cannot break up stubborn scale in the wellbore. In order to break up stubborn scale in the wellbore, the existing method is to use a screw to provide rotational power to drive a drill bit or milling cone for milling, which can effectively remove stubborn scale in the wellbore, but has no obvious effect on cleaning and repairing the wellbore and on washing and plugging removal of perforation holes on the casing. For sand washing and scale removal in horizontal wells, if a screw is used to provide rotational power, the screw is relatively long, has poor passability and has a high risk of sticking, so a sand washing and milling tool capable of providing rotational power is needed to be developed. SUMMARY

[0003] The purpose of the present application is to provide a horizontal well high-efficiency rotational flow milling sand washer, which solves the problem that conventional sand washing tools have no rotational milling function and screw drilling tools have no rotational flow jetting effect, and the sand washing and scale removal effect is not ideal.

[0004] The purpose of the present application is to provide a horizontal well high-efficiency rotational flow milling sand washing method, which improves the milling sand washing efficiency.

[0005] The first technical solution adopted by the present application is a horizontal well high-efficiency rotational flow milling sand washer, which comprises an outer spiral sand washer body, an axial nozzle and an axial nozzle pressure cap are arranged on one end face of the outer spiral sand washer body, the outer spiral sand washer body is in a hollow cylindrical shape, the end head of the outer spiral sand washer body at one end of the axial nozzle is in a circular truncated cone shape, a spiral flow guide groove a is arranged on the cylindrical surface of the outer spiral sand washer body, a core pipe is connected to the other end of the outer spiral sand washer body, one end of the core pipe is inserted into the outer spiral sand washer body, the part of the core pipe located in the outer spiral sand washer body is connected with an upper joint, an inner spiral sand washer body is arranged in the outer spiral sand washer body, the inner spiral sand washer body is in a hollow cylindrical shape, a spiral flow guide groove b is arranged on the cylindrical surface of the inner spiral sand washer body, a core shaft is arranged in the inner spiral sand washer body, and the core shaft is connected with the end head of the core pipe extending into the outer spiral sand washer body.

[0006] The first technical solution of the present application is also characterized in that,

[0007] The outer spiral sand ejector body is a right-hand spiral tooth, the inner spiral sand ejector body is a left-hand spiral tooth, and the inner spiral sand ejector body is provided with a side through hole on one side wall close to the end of the outer spiral sand ejector body.

[0008] The axial nozzle is provided with two axial nozzle pressure caps, and the two axial nozzles are centrally symmetrically arranged on the end face of the outer spiral sand ejector body, and the end face of the outer spiral sand ejector body provided with the axial nozzle is also provided with four radial flow distribution grooves, the outlet of each axial nozzle pressure cap is communicated with two flow distribution grooves, the outer side of the circular truncated cone-shaped end of the outer spiral sand ejector body is uniformly distributed with four straight guide grooves, the straight guide grooves and the flow distribution grooves are one-to-one corresponding and communicated, and the spiral guide groove a is also provided with four, and the spiral guide groove a and the straight guide groove are one-to-one corresponding and communicated at the circular truncated cone large diameter of the outer spiral sand ejector body.

[0009] The inner part of the outer spiral sand ejector body is provided with four axial holes, each straight guide groove is provided with a lateral nozzle and a corresponding lateral nozzle pressure cap, the inner hole of the lateral nozzle is one-to-one corresponding and communicated with the axial hole of the outer spiral sand ejector body, and the axial direction of the lateral nozzle is a composite angle of 60° of axial angle and 60° of radial angle;

[0010] The axial nozzle is provided with a sealing ring a, the sealing ring a is arranged between the axial nozzle and the outer spiral sand ejector body, the axial nozzle pressure cap is pressed on the outer end face of the axial nozzle, and the axial nozzle pressure cap and the outer spiral sand ejector body are connected through threads.

[0011] The outer surface of the outer spiral sand ejector body is coated with a hard alloy grinding layer.

[0012] The spiral tooth outer edge of the inner spiral sand ejector body is tightly matched with the inner wall of the outer spiral sand ejector body, and the spiral tooth of the inner spiral sand ejector body and the inner wall of the outer spiral sand ejector body are provided with sealing glue, the connection between the outer spiral sand ejector body and the core pipe is provided with an anti-loose ring, and the outer spiral sand ejector body and the anti-loose ring are connected through threads.

[0013] Two bearings are arranged between the mandrel and the inner spiral sand ejector body, the two bearings are respectively close to the two ends of the mandrel, the bearing inner ring of the bearing is matched with the outer circle of the mandrel, the bearing outer ring of the bearing is matched with the inner hole of the inner spiral sand ejector body, the mandrel is provided with an adjusting ring, the connecting end of the inner spiral sand ejector body and the core pipe is connected with the adjusting ring through threads, the side end face of the adjusting ring is on the end face of one bearing outer ring, and the flange of the other side end face is provided with a jackscrew, and the jackscrew is on the positioning groove arranged on the inner spiral sand ejector body.

[0014] The core shaft is provided with a sealing ring b located between the core shaft and the inner wall of the inner spiral sand flusher body, the outer circle of the core tube is provided with a dustproof ring matched with the inner hole of the adjusting ring, and the core tube and the adjusting ring are provided with an axial gap, and the sidewall of the connecting end of the core tube and the inner spiral sand flusher body is provided with a square hole;

[0015] The core tube is connected with the upper joint through threads, the outer circle of the middle part of the core tube is provided with a sealing ring c located between the core tube and the inner wall of the outer spiral sand flusher body, the middle part of the inner hole of the upper joint is provided with a sealing ring d located between the upper joint and the outer circle of the right side of the core tube, and the thread root of the connection between the upper joint and the core tube is provided with a friction ring.

[0016] The second technical scheme of the present application is a horizontal well high-efficiency cyclone milling sand flushing method, which applies the horizontal well high-efficiency cyclone milling sand flusher to flush sand, specifically, assembles the sand flusher, connects the sand flushing pipe column, lowers the sand flushing pipe column in the casing, explores the position of sand deposits in the well, connects the sand flushing pump truck through the wellhead oil pipe, starts the pump to perform sand flushing and milling operation, and the sand flushing fluid enters the inner cavity of the core tube from the inner cavity of the upper joint of the sand flusher through the centralizer, thereby providing the sand flusher with three-stage positive rotation power and rotation milling power, and the sand flushing is realized.

[0017] The second technical scheme of the present application is also characterized in that,

[0018] The specific implementation is as follows:

[0019] Step 1, assemble the sand flusher, select the nozzle size according to the sand flushing construction displacement, control the jet speed at 60-100 m / s to ensure sufficient jet impact effect without damaging the casing;

[0020] Step 2, connect the sand flushing pipe column, the structure of the sand flushing pipe column is sequentially composed of the sand flusher, the centralizer and the oil pipe from bottom to top, and the centralizer is connected with the sand flusher and the oil pipe through the oil pipe threads;

[0021] Step 3, lower the sand flushing pipe column in the casing, slowly lower the pipe column, and explore the position of sand deposits in the well;

[0022] Step 4, after the sand deposits are found, lift the pipe column by 0.3-0.5 meters, connect the sand flushing pump truck through the wellhead oil pipe, set the sand flushing displacement, and start the pump to perform sand flushing and milling operation;

[0023] Step 5, the sand flushing fluid enters the inner cavity of the core tube from the inner cavity of the upper joint of the sand flusher through the centralizer, flows out from the square hole formed in the connecting end of the core tube and the inner spiral sand flusher body, impacts the spiral teeth of the inner spiral sand flusher body, the inner spiral sand flusher body is a right-hand spiral, the fluid generates a positive rotation torque on the inner spiral in the direction of the tight grip of the core shaft thread, thereby providing the sand flusher with the first-stage rotation power;

[0024] Step 6, after the sand washing fluid comes out from the left side of the inner spiral sand washer body, 1 / 3 of the sand washing fluid passes through the side through hole of the inner spiral sand washer body and enters from the axial nozzle of the outer spiral sand washer body, and the sand bridge in the front direction is impacted, and 2 / 3 of the sand washing fluid enters from the axial hole of the outer spiral sand washer body and is sprayed from the four lateral nozzles of the outer spiral sand washer body, which not only generates a spraying force to the side front, but also generates a circumferential tangential spraying force, and the reaction of the circumferential tangential spraying generates a positive rotation torque on the outer spiral, thereby providing the second level of rotation power of the sand washer;

[0025] Step 7, the fluid sprayed from the axial nozzle of the outer spiral sand washer body returns from the flow dividing groove, flows through the right-angle flow guide groove, and returns from the spiral flow guide groove a on the cylindrical surface of the outer spiral sand washer body together with the fluid returned from the corresponding lateral nozzle, and returns to the ground from the tubing and the casing annulus, and the outer spiral sand washer body is a left-handed spiral, and the fluid flowing through the spiral flow guide groove b generates a positive rotation torque on the outer spiral sand washer body, thereby providing the third level of rotation power of the sand washer;

[0026] The three levels of positive rotation power provide sufficient rotation milling power for the sand washer, remove stubborn dirt and stones on the inner wall of the casing, flush the plug of the perforating gun on the unblocked casing, break the stubborn dirt and stones in the casing, and achieve sand washing.

[0027] The beneficial effects of the present application are:

[0028] 1) The horizontal well efficient rotational flow milling sand washer of the present application can generate rotation power independently, has the tangential flushing function of the rotational flow sand washing tool and the milling function of the screw power drill.

[0029] 2) The lateral nozzle of the sand washer of the present application is beneficial to the stripping of the scale block on the inner wall of the casing, avoids the positive impact on the inner wall of the casing, thereby reducing the damage to the casing, can remove the stubborn dirt and stones on the inner wall of the casing, has a significant flushing and unblocking effect on the plug of the perforating gun on the casing, and is beneficial to the dredging of the perforating gun.

[0030] 3) The left end face, conical face and outer cylindrical face of the sand washer of the present application are all coated with a hard alloy grinding layer for milling the stubborn dirt and stones in the casing. When the sand washer rotates, the grinding layer has a breaking and stripping effect on the stubborn dirt and stones, and has a grinding and refining effect on larger scale blocks, which is beneficial to the carrying of the sand washing fluid out of the wellbore.

[0031] 4) Two thrust bearings are installed between the mandrel and the inner spiral of the sand washer, which are used to bear the acting force on the left and right ends of the mandrel, and can greatly reduce the rotation resistance of the rotating parts of the sand washer.

[0032] 5) The inner spiral positioning groove, adjusting ring, top wire and core tube of the sand washer are connected and locked in sequence, which ensures the axial positioning of the two bearings.

[0033] 6) The spiral assembly, the anti-dropping ring and the upper joint of the sand washer are connected and locked in sequence, ensuring that the anti-dropping ring protects the spiral assembly from being stuck and eliminating the risk of falling into the well of the rotating part of the sand washer.

[0034] 7) The centralizer is a flexible centralizer with free bidirectional traction at both ends. Whether the sand washing string is pulled up or lowered, the spring sheet of the centralizer is subjected to traction and produces tensile deformation. Compared with the spring sheet of the traditional flexible centralizer which is subjected to pushing and is prone to bending deformation, the risk of spring sheet folding and sticking is avoided.

[0035] 8) The sand washer has three levels of rotary power, which can generate sufficient milling rotary power, and the three rotary torques are beneficial to the tightening of the positive thread, reducing the risk of tool tripping.

[0036] 9) The left end face, conical face and outer cylindrical face of the outer spiral of the sand washer are provided with flow guide grooves, and the outer edge of the flow guide grooves is sharp, which can produce scraping effect, especially the flow guide grooves on the outer cylindrical face can scrape and trim the inner wall of the casing.

[0037] 10) The sand washer forms a small wellbore inner diameter, and the pipe string bottoming effect will increase the rotary resistance of the sand washer milling, the bidirectional traction flexible centralizer designed in the application has good centering effect and can reduce the pipe string bottoming friction, ensuring the output efficiency of the rotary power of the sand washer.

[0038] 11) The anti-dropping ring is connected to the right end of the outer spiral of the sand washer. If the sand washer is stuck when the string is pulled up, the anti-dropping ring can prevent the rotating part of the sand washer from falling off, avoiding the fish falling accident in the well.

[0039] 12) The horizontal well efficient rotational flow milling sand washing method of the application uses the horizontal well efficient rotational flow milling sand washer of the application to produce three levels of rotary power independently, remove stubborn scale on the inner wall of the casing, flush the plug of the perforating gun on the casing, break the stubborn scale in the casing, and the sand washing effect is remarkable. BRIEF DESCRIPTION OF DRAWINGS

[0040] Figure 1 is a structural schematic view of the horizontal well efficient rotational flow milling sand washer of the application;

[0041] Figure 2 is a structural schematic view of the outer spiral sand washer body of the horizontal well efficient rotational flow milling sand washer of the application, wherein Figure 2 (a) is a front view of the outer spiral sand washer body, Figure 2 (b) is a side view of the outer spiral sand washer body;

[0042] Figure 3 is a structural schematic view of the inner spiral sand washer body of the horizontal well efficient rotational flow milling sand washer of the application, wherein Figure 3 (a) is a side view of the inner spiral sand washer body, Figure 3(b) is a front view of the internal spiral sand flushing device;

[0043] Figure 4 This is a schematic diagram of a milled and sand-filled tubular column;

[0044] Figure 5 This is a schematic diagram illustrating the working principle of the horizontal well high-efficiency vortex milling and sand flushing device of the present invention.

[0045] In the diagram, 1. Axial nozzle cap, 2. Axial nozzle, 3. Sealing ring a, 4. Axial hole, 5. Sealing ring b, 6. Bearing, 7. External spiral sand flusher body, 8. Internal spiral sand flusher body, 9. Mandrel, 10. Dustproof ring, 11. Adjusting ring, 12. Set screw, 13. Small hexagonal hole, 14. Square hole, 15. Sealing ring c, 16. Anti-detachment ring, 17. Core tube, 18. Friction ring, 19. Sealing ring d, 20. Large hexagonal hole, 21. Upper connector, 22. Diverter groove, 23. Right-angle guide groove, 24. Spiral guide groove a, 25. Grinding layer, 26. Side through hole, 27. Spiral guide groove b, 28. Positioning groove, 29. Oil pipe, 30. Sleeve, 31. Centralizer, 32. Sand flusher, 33. Sand and scale, 34. Side nozzle, 35. Side nozzle cap. Detailed Implementation

[0046] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0047] Example 1

[0048] This embodiment provides a high-efficiency cyclone milling and sand-draining device for horizontal wells, such as... Figure 1 As shown, it includes the outer spiral sand flushing body 7, such as Figure 2 As shown, the outer spiral sandblaster body 7 has a right-handed spiral tooth. One end face of the outer spiral sandblaster body 7 is provided with an axial nozzle 2 and an axial nozzle cap 1. The axis of the axial nozzle 2 is parallel to the axis of the outer spiral sandblaster body 7. The outer spiral sandblaster body 7 is a hollow cylindrical shape, and the end with the axial nozzle 2 is a frustum shape. The cylindrical surface of the outer spiral sandblaster body 7 is provided with a spiral guide groove a24. The opening of the spiral guide groove a24 has sharp edges, which scrape and trim the inner wall of the sleeve when the sandblaster rotates. The other end is connected to a core tube 17. One end of the core tube 17 is inserted into the outer spiral sandblaster body 7. The part of the core tube 17 located in the outer spiral sandblaster body 7 is connected to an upper connector 21. An inner spiral sandblaster body 8 is provided inside the outer spiral sandblaster body 7. Figure 3As shown, the inner spiral sand blaster body 8 is hollow cylindrical shape, the inner spiral sand blaster body 8 is left-hand spiral tooth, the inner spiral sand blaster body 8 is provided with a side hole 26 on one end of the side wall near the end of the outer spiral sand blaster body 7, the inner spiral sand blaster body 8 is provided with a spiral flow guide groove b27 on the cylindrical surface, the inner spiral sand blaster body 8 is provided with a mandrel 9, and the mandrel 9 is connected with the end of the core pipe 17 extending into the outer spiral sand blaster body 7.

[0049] Embodiment 2

[0050] The embodiment provides a high-efficiency rotary flow grinding and milling sand blaster for horizontal well, on the basis of embodiment 1, two axial nozzles 2 are arranged, and an axial nozzle cap 1 is arranged on each axial nozzle 2, the two axial nozzles 2 are arranged in central symmetry on the end face of the outer spiral sand blaster body 7, the axial nozzle 2 generates front jetting, has strong impact effect, can achieve the effect of breaking through the sand bridge center, and the end face of the outer spiral sand blaster body 7 provided with the axial nozzle 2 is also provided with four radial flow distribution grooves 22, the outlet of each axial nozzle cap 1 is communicated with two flow distribution grooves 22, the outer side of the circular truncated cone-shaped end of the outer spiral sand blaster body 7 is uniformly distributed with four straight flow guide grooves 23, the straight flow guide grooves 23 and the flow distribution grooves 22 are one-to-one corresponding and communicated, and four spiral flow guide grooves a24 are also arranged, and the spiral flow guide grooves a24 and the straight flow guide grooves 23 are one-to-one corresponding and communicated at the circular truncated cone large diameter of the outer spiral sand blaster body 7.

[0051] Embodiment 3

[0052] The embodiment provides a high-efficiency rotary flow grinding and milling sand blaster for horizontal well, on the basis of embodiments 1-2, four axial holes 4 are arranged in the inner part of the outer spiral sand blaster body 7, a lateral nozzle 34 and a corresponding lateral nozzle cap 35 are arranged on each straight flow guide groove 23, the lateral nozzle 34 avoids front impact on the casing, reduces damage to the casing, tangential impact formed by the lateral nozzle 34 can produce peeling effect, can remove stubborn dirt and stones on the inner wall of the casing, has a significant flushing and unblocking effect on the perforating gun hole blockage on the casing, the inner hole of the lateral nozzle 34 and the axial hole 4 of the outer spiral sand blaster body 7 are one-to-one corresponding and communicated, and the axial direction of the lateral nozzle 34 is a composite angle of an axial angle 60° and a radial angle 60°, that is, the axial line is rotated 60° in the positive direction to the left, and then the left end face is rotated 60° counterclockwise.

[0053] The axial nozzle 2 is provided with a sealing ring a3, the sealing ring a3 is arranged between the axial nozzle 2 and the outer spiral sand blaster body 7, the axial nozzle cap 1 is pressed on the outer end face of the axial nozzle 2, and the axial nozzle cap 1 and the outer spiral sand blaster body 7 are connected through threads, the axial nozzle cap 1 is tightly pressed on the outer end face of the axial nozzle 2, the inner hole of the axial nozzle cap 1 is a hexagonal hole, which not only leaves the jet flow channel of the axial nozzle 2, but also facilitates the installation and tightening of the axial nozzle cap 1.

[0054] The outer spiral sand buster body 7 is coated with a hard alloy grinding layer 25 on the outer surface. When the sand buster rotates, the grinding layer 25 has a cutting and milling effect on stubborn dirt and stones, and a grinding and refining effect on larger dirt blocks, which are used to mill stubborn dirt and stones in the casing.

[0055] Embodiment 4

[0056] The embodiment provides a horizontal well high-efficiency spiral flow milling sand buster. On the basis of embodiments 1-3, the spiral teeth of the inner spiral sand buster body 8 are tightly matched with the inner wall of the outer spiral sand buster body 7, and the spiral teeth of the inner spiral sand buster body 8 and the matching surface of the inner wall of the outer spiral sand buster body 7 are provided with sealing glue, and the spiral teeth of the inner spiral sand buster body 8 are welded and connected with the inner hole of the outer spiral sand buster body 7 at the right end (the connection end of the core pipe 17), to form a spiral assembly.

[0057] The connection part of the outer spiral sand buster body 7 and the core pipe 17 is provided with a anti-falling ring 16, and the outer spiral sand buster body 7 and the anti-falling ring are connected through threads. The anti-falling ring 16, the core pipe 17 and the upper joint 21 all have axial gaps, to ensure that the outer spiral sand buster body 7 rotates freely with the anti-falling ring 16. The inner hole of the connection end of the core pipe 17 and the upper joint is a large hexagonal hole 20, to facilitate the placement of a hexagonal wrench when the core pipe 17 is assembled. The inner hole of the connection end of the core shaft 9 and the core pipe 17 is a small hexagonal hole 13.

[0058] Embodiment 5

[0059] The embodiment provides a horizontal well high-efficiency spiral flow milling sand buster. On the basis of embodiments 1-4, two bearings 6 are arranged between the core shaft 9 and the inner spiral sand buster body 8. The two bearings are respectively close to the two ends of the core shaft 9. The bearing inner ring of the bearing 6 is matched with the outer circle of the core shaft 9, and the bearing outer ring of the bearing 6 is matched with the inner hole of the inner spiral sand buster body 8. The core shaft is positioned with the bearing inner ring through the outer circle step, and the inner spiral sand buster body 8 is positioned with the bearing outer ring through the outer circle step. The core shaft 9 is provided with an adjusting ring 11, and the connection end of the inner spiral sand buster body 8 and the core pipe 17 is connected with the adjusting ring 11 through threads. One side end surface of the adjusting ring 11 is abutted on one end surface of the bearing outer ring. The rotation depth of the adjusting ring 11 can be adjusted to adjust the axial matching tightness of the two bearings 6. The flange of the other side end surface is provided with a jackscrew 12, which is abutted in the positioning groove 28 arranged on the inner spiral sand buster body 8, to prevent the adjusting ring 11 from loosening and to prevent the relative inner spiral 8 from being circumferentially displaced, so as to affect the matching tightness of the two bearings 6.

[0060] The mandrel is equipped with a sealing ring b5 and a dustproof ring 10. The dustproof ring 10 fits with the inner hole of the adjusting ring 11 to prevent solid impurities from entering the left cavity and affecting the operation of the two bearings 6. The sealing ring b5 is located between the mandrel 9 and the inner wall of the inner spiral sand flusher body 8. The outer circle of the core tube 17 is equipped with a dustproof ring 10, which fits with the inner hole of the adjusting ring 11. The core tube 17 and the adjusting ring 11 are provided with an axial gap to ensure that the adjusting ring 11 rotates flexibly with the spiral assembly. This axial gap must be less than the depth of the positioning groove 28 of the inner spiral sand flusher body 8 to limit the loosening and backing of the top screw 12, so as not to disengage from the positioning groove 28 and ensure that the adjusting ring 11 is reliably positioned. The positioning groove 28, adjusting ring 11, top screw 12, and core tube 17 of the inner spiral sand flusher body 8 are interlocked and locked together to ensure the axial positioning of the two bearings 6.

[0061] A square hole 14 is provided on the side wall of the connection end between the core tube 17 and the inner spiral sand flushing body 8. The core tube 17 is connected to the upper connector 21 by a thread. There are multiple circumferentially distributed square holes 14 on the middle tube wall of the core tube 17. The long side of the hole is along the axial direction, which can increase the flow area and reduce the flow resistance while ensuring strength. A sealing ring c15 is provided on the outer circle of the middle part of the core tube 17. The sealing ring c15 is located between the core tube 17 and the inner wall of the outer spiral sand flushing body 7. A sealing ring d19 is provided in the middle of the inner hole of the upper connector 21. The sealing ring d19 is located between the upper connector 21 and the outer circle of the right side of the core tube 17. A friction ring 18 is provided at the root of the thread connecting the upper connector 21 and the core tube 17 to increase the friction of the threaded connection between the core tube 17 and the upper connector 21 and enhance the anti-loosening effect.

[0062] Example 6

[0063] This embodiment provides a method for efficient vortex milling and sand flushing in horizontal wells. Sand flushing is performed using any one of the efficient vortex milling and sand flushing devices from embodiments 1-4. Specifically, the sand flushing device is assembled, the sand flushing string is connected, and the sand flushing string is lowered into the casing to locate the sand deposits downhole. The wellhead tubing is connected to a sand flushing pump truck, and the pump is started to perform the sand flushing and milling operation. The sand flushing fluid flows from the tubing through the centralizer and into the inner cavity of the core tube 17 from the upper connector of the sand flushing device, providing three stages of positive rotational power to the sand flushing device, thus providing rotational milling power and achieving sand flushing.

[0064] Example 7

[0065] This embodiment provides a high-efficiency cyclone milling and sand-removing method for horizontal wells, which is implemented according to the following steps based on Embodiment 6:

[0066] Step 1) Assemble the sand flushing device. Select the nozzle size according to the sand flushing operation volume. To ensure sufficient jet impact without damaging the casing, control the jetting speed at 60-100 m / s. Therefore, for a 0.6-1.0 m... 3For a displacement of / min, it is recommended to install six 6mm nozzles, for a range of 1.1-1.8m. 3 The displacement is 6 / min and six 8mm nozzles are installed;

[0067] Step 2) as Figure 4 As shown, the sand flushing tubing is connected. The sand flushing tubing consists of a sand flusher 32, a stabilizer 31, and an oil pipe 29 from bottom to top. The stabilizer 31 is connected to the sand flusher 32 and the oil pipe 29 by threads through the oil pipe 29.

[0068] Step 3) Run the sand flushing string into the casing 30, slowly lower the string, and explore the location of the sand and scale 33 in the well.

[0069] Step 4) After detecting sand and scale, raise the tubing string 0.3-0.5 meters, connect the wellhead tubing to the sand flushing pump truck, set the sand flushing displacement, and start the pump to perform sand flushing and milling operations. The sand flushing displacement should be referenced to the nozzle size; for six 6mm nozzles, the displacement range is 0.6-1.0m. 3 / min; six 8mm nozzles with a displacement range of 1.1-1.8m. 3 / min;

[0070] Step 5, as follows Figure 5 As shown, the flushing fluid enters the inner cavity of the core tube 17 from the inner cavity of the connector 21 on the upper part of the flusher 32 through the oil pipe and the centralizer 31. It flows out from the square hole 14 at the connection end between the core tube 17 and the inner spiral flusher body 8, impacting the spiral teeth of the inner spiral flusher body 8. The inner spiral flusher body 8 is a right-hand spiral. The fluid generates a positive rotational torque on the inner spiral, i.e., the tightening direction of the core thread, providing the first stage of rotational power for the flusher.

[0071] Step 6: After the flushing fluid comes out from the left side of the inner spiral flushing body 8, 1 / 3 of it enters through the side through hole 26 of the inner spiral flushing body 8 and is sprayed out from the axial nozzle 2 of the outer spiral flushing body 7 to impact the sand bridge in front. 2 / 3 of the flushing fluid enters through the axial hole 4 of the outer spiral flushing body 7 and is sprayed out from the four side nozzles 34 of the outer spiral flushing body 7, which generates both a jetting force to the side and a circumferential tangential jetting force. The reaction force of the circumferential tangential jetting generates a positive rotational torque on the outer spiral, providing the second stage of rotational power for the flushing device.

[0072] Step 7: The fluid ejected from the axial nozzle 2 of the outer spiral sand flusher body 7 returns from the diversion groove 22, flows through the right-angle guide groove 23, and together with the fluid returned from the corresponding lateral nozzle 34, returns from the spiral guide groove a24 on the cylindrical surface of the outer spiral sand flusher body 7, and returns to the ground through the annulus of the oil pipe 29 and the casing 30. The outer spiral sand flusher body 7 is a left-handed spiral. The fluid flowing through the spiral guide groove b27 generates a positive rotational torque on the outer spiral sand flusher body 7, providing the third stage of rotational power for the sand flusher.

[0073] The three-stage positive rotation power provides sufficient rotation milling power for the sand cleaner, removes stubborn dirt and stones on the inner wall of the casing 30, flushes the perforation plug on the blocked casing 30, breaks the stubborn dirt and stones in the milled casing, and realizes sand washing.

[0074] The sand washing process of the horizontal well high-efficiency cyclone milling sand washing method has the following advantages:

[0075] The axial nozzle 2 produces a frontal jet, has strong impact effect, and can achieve the effect of breaking through the center of the sand and dirt 33. The lateral nozzle 34 avoids frontal impact on the casing 30, reduces the risk of casing 30 damage, and the tangential impact formed by the lateral nozzle can produce a cutting and peeling effect on the dirt on the inner wall of the casing 30, which can remove stubborn dirt on the inner wall of the casing 30 and has a significant flushing and unblocking effect on the perforation plug on the casing.

[0076] The connection threads of the mandrel 9 and the core pipe 17, the connection threads of the core pipe 17 and the upper joint 21, the connection threads of the upper joint 21 and the centralizer 31, and the connection threads of all the oil pipes 29 are all positive threads, and the three-stage positive rotation power produces a tight grip on the positive threads, reducing the risk of pipe string thread loosening and disconnection.

[0077] The outer spiral 7 and the inner spiral 8 are locally welded, the bearing 6, the adjusting ring 11, and this welded part are the weak points of the tensile strength of the sand cleaner. If the sand cleaner is stuck, the upward unblocking force may cause these weak points to fail, and then the anti-disengagement ring 16 will hang on the outer step of the core pipe 17 to prevent the sand cleaner from falling off and avoid causing a fish falling accident in the well.

[0078] The connection threads of the outer spiral 7 and the anti-disengagement ring 16 are also positive threads, and the rotation of the outer spiral 7 also produces a tight grip on the threads, reducing the risk of loosening of the anti-disengagement ring 16. The axial gap between the anti-disengagement ring 16 and the upper joint 21 is small, and if the anti-disengagement ring 16 loosens and moves to the right, the left end surface of the upper joint 21 will prevent the anti-disengagement ring 16 from loosening, and the friction of the anti-disengagement ring 16 will cause the anti-disengagement ring 16 to tighten and move to the left.

[0079] The inner diameter of the wellbore after milling is small, and the pipe string bottoming effect will increase the rotation resistance of the sand cleaner milling, and the innovative design of the bidirectional traction elastic centralizer has good centering effect, which can reduce the pipe string bottoming friction and ensure the output efficiency of the sand cleaner rotation power.

Claims

1. A high-efficiency cyclone mill and sand miller for horizontal wells, characterized in that, The utility model provides external spiral sand washer body (7) one end end face is equipped with axial nozzle (2) and axial nozzle pressure cap (1), external spiral sand washer body (7) is hollow cylindrical shape, and external spiral sand washer body (7) is equipped with the end head of axial nozzle (2) one end is circular truncated cone shape, the cylindrical surface of external spiral sand washer body (7) is equipped with spiral flow guide groove a (24), the other end is connected with core pipe (17), core pipe (17) one end inserts external spiral sand washer body (7), and core pipe (17) is located in the part of external spiral sand washer body (7) and is connected with upper joint (21), and external spiral sand washer body (7) is equipped with internal spiral sand washer body (8) in it, internal spiral sand washer body (8) is hollow cylindrical shape, and the cylindrical surface of internal spiral sand washer body (8) is equipped with spiral flow guide groove b (27), and internal spiral sand washer body (8) is equipped with core shaft (9) in it, and the end head of core shaft (9) is connected with the core pipe (17) that extends into external spiral sand washer body (7). External spiral sand washer body (7) is right-hand spiral tooth, internal spiral sand washer body (8) is left-hand spiral tooth, and the side through -hole (26) is set up in the side wall of the end head one end of internal spiral sand washer body (8) close to external spiral sand washer body (7), and the spiral tooth outer edge of internal spiral sand washer body (8) is tightly matched with the inner wall of external spiral sand washer body (7), and the spiral tooth of internal spiral sand washer body (8) is matched with the inner wall of external spiral sand washer body (7) and is provided with sealing glue, and is welded and connected in the inner hole of external spiral sand washer body (7) at the right end of the spiral tooth of internal spiral sand washer body (8) that is connected with the end of core pipe (17), and constitutes spiral assembly. The axial nozzle (2) is provided with two, and each axial nozzle (2) is provided with an axial nozzle pressure cap (1), the two axial nozzles (2) are centrally symmetrically arranged on the end face of the external spiral sand washer body (7), and the end face of the external spiral sand washer body (7) provided with the axial nozzle (2) is further provided with four radial flow distribution grooves (22), the outlet of each axial nozzle pressure cap (1) is communicated with two flow distribution grooves (22), the circular truncated cone shaped end of the external spiral sand washer body (7) is uniformly distributed with four straight guide grooves (23), the straight guide grooves (23) and the flow distribution grooves (22) are one-to-one corresponding and communicated, and the spiral flow guide groove a (24) is also provided with four, the spiral flow guide groove a (24) and the straight guide groove (23) are one-to-one corresponding and communicated at the circular truncated cone large diameter of the external spiral sand washer body (7). The external spiral sand washer body (7) is provided with four axial holes (4) inside, each straight guide groove (23) is provided with a lateral nozzle (34) and a corresponding lateral nozzle pressure cap (35), the inner hole of the lateral nozzle (34) is one-to-one corresponding and communicated with the axial hole (4) of the external spiral sand washer body (7), and the axial direction of the lateral nozzle (34) is a composite angle of 60° of axial angle and 60° of radial angle. The axial nozzle (2) is provided with a sealing ring a (3), which is arranged between the axial nozzle (2) and the outer spiral sand washer body (7), the axial nozzle pressing cap (1) is pressed on the outer end surface of the axial nozzle (2), and the axial nozzle pressing cap (1) is connected with the outer spiral sand washer body (7) through threads.

2. The horizontal well high-efficiency cyclone mill and sand cleaner according to claim 1, characterized in that, The outer surface of the outer spiral sand washer body (7) is coated with a hard alloy grinding layer (25).

3. The horizontal well high-efficiency cyclone mill and sand cleaner according to claim 1, characterized in that, The outer spiral sand washer body (7) is provided with a anti-off ring (16) at the connection with the core pipe (17), and the outer spiral sand washer body (7) is connected with the anti-off ring through threads.

4. The horizontal well high-efficiency cyclone mill and sand cleaner according to claim 3, characterized in that, The core shaft (9) and the inner spiral sand washer body (8) are provided with two bearings (6), which are respectively close to the two ends of the core shaft (9), the bearing inner ring of the bearing (6) is matched with the outer circle of the core shaft (9), the bearing outer ring of the bearing (6) is matched with the inner hole of the inner spiral sand washer body (8), the core shaft (9) is provided with an adjusting ring (11), the connection end of the inner spiral sand washer body (8) and the core pipe (17) is connected with the adjusting ring (11) through threads, one side end surface of the adjusting ring (11) is pressed on the end surface of one bearing outer ring, and the flange of the other side end surface is provided with a jackscrew (12), the jackscrew (12) is pressed in the positioning groove (28) arranged on the inner spiral sand washer body (8).

5. The horizontal well high-efficiency cyclone mill and sand cleaner of claim 1, wherein, The core shaft is provided with a sealing ring b (5), which is located between the core shaft (9) and the inner wall of the inner spiral sand washer body (8), the outer circle of the core pipe (17) is provided with a dustproof ring (10), the dustproof ring (10) is matched with the inner hole of the adjusting ring (11), and the core pipe (17) and the adjusting ring (11) are provided with an axial gap, and the connection end of the core pipe (17) and the inner spiral sand washer body (8) is provided with a square hole (14). The core pipe (17) is connected with the upper joint (21) through threads, the outer circle of the middle part of the core pipe (17) is provided with a sealing ring c (15), the sealing ring c (15) is located between the inner wall of the core pipe (17) and the outer spiral sand washer body (7), the middle part of the inner hole of the upper joint (21) is provided with a sealing ring d (19), the sealing ring d (19) is located between the upper joint (21) and the right outer circle of the core pipe (17), and the thread root of the connection between the upper joint (21) and the core pipe (17) is provided with a friction ring (18).

6. The method for high-efficiency abrasive milling and sand washing of horizontal well, the sand washing is carried out by using the high-efficiency abrasive milling and sand washing device of horizontal well according to any one of claims 1-5, characterized in that, Specifically, the sand washer is assembled, the sand washing pipe string is connected, the sand washing pipe string is lowered into the casing, the position of the downhole sand is explored, the wellhead tubing is connected with the sand washing pump truck, the pump is started to carry out sand washing and milling operation, the sand washing fluid enters the inner cavity of the core pipe (17) from the inner cavity of the upper joint of the sand washer after passing through the centralizer from the sand washer, which provides three-stage positive rotation power for the sand washer, provides rotation and milling power for the sand washer, and realizes sand washing.

7. The horizontal well high-efficiency cyclone milling and sand washing method according to claim 6, characterized in that, Specifically, the following steps are implemented: Step 1, assemble the sand washer, select the nozzle size according to the sand washing construction displacement, control the jet speed at 60-100 m / s to ensure sufficient jet impact effect without damaging the casing; Step 2, connect the sand washing string, the structure of the sand washing string is sequentially connected from bottom to top as the sand washer (32), the centralizer (31), and the oil pipe (29), the centralizer (31) is threadedly connected with the sand washer (32) and the oil pipe (29) through the oil pipe (29); Step 3, lower the sand washing string into the casing (30), slowly lower the string, and explore the position of the sand scale (33) in the well; Step 4, after the sand scale is found, the string is lifted by 0.3-0.5 meters, the oil pipe at the wellhead is connected with the sand washing pump truck, the sand washing displacement is set, the pump is started, and the sand washing and milling operation is performed; Step 5, the sand washing fluid enters the inner cavity of the core pipe (17) from the inner cavity of the upper joint of the sand washer (32) through the centralizer (31) from the oil pipe, flows out from the square hole (14) formed at the connection end of the core pipe (17) and the inner spiral sand washer body (8), impacts the spiral teeth of the inner spiral sand washer body (8), the inner spiral sand washer body (8) is a right-hand spiral, the fluid generates a positive rotation torque on the inner spiral in the direction of the tight grip of the core shaft thread, and the first-stage rotation power of the sand washer is provided; Step 6, after the sand washing fluid comes out from the left side of the inner spiral sand washer body (8) by 1 / 3, it enters the side through hole (26) of the inner spiral sand washer body (8), is sprayed out from the axial nozzle (2) of the outer spiral sand washer body (7), impacts the sand bridge in front, and 2 / 3 of the sand washing fluid enters the axial hole (4) of the outer spiral sand washer body (7) and is sprayed out from the four lateral nozzles (34) of the outer spiral sand washer body (7), which generates a spraying force to the side front and a circumferential tangential spraying force, the reaction of the circumferential tangential spraying generates a positive rotation torque on the outer spiral, and the second-stage rotation power of the sand washer is provided; Step 7, the fluid sprayed out from the axial nozzle (2) of the outer spiral sand washer body (7) returns from the flow dividing groove (22) and flows through the right-angle flow guide groove (23), returns from the spiral flow guide groove a (24) on the cylindrical surface of the outer spiral sand washer body (7) together with the fluid returned from the corresponding lateral nozzle (34), and returns to the ground from the annulus of the oil pipe (29) and the casing (30), the outer spiral sand washer body (7) is a left-hand spiral, the fluid flowing through the spiral flow guide groove b (27) generates a positive rotation torque on the outer spiral sand washer body (7), and the third-stage rotation power of the sand washer is provided; The three-stage positive rotation power provides sufficient rotation and milling power for the sand washer, removes stubborn dirt and stones on the inner wall of the casing (30), flushes the plugging material of the perforating gun on the casing (30), breaks the stubborn dirt and stones in the casing, and realizes sand washing.

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