A device and process for removing rust from the inner wall of a tubing by using a coiled tubing

Abstract

The present application relates to oil pipe inner wall rust removal technical field, especially in oil pipe inner wall rust removal device and process using coiled tubing, for solving the problem that the pipe material can only be cleaned on the ground at present, the device comprises: continuous scraping cutting module; The continuous scraping cutting module comprises: an arc-shaped scraping cutting gear, which is fixedly rotated in the middle of the lower joint; One end of the double-head gear shaft is connected with a bevel gear, and the other end is connected with a spur cylindrical gear; An inner gear ring is connected in the third upper joint; The process comprises: obtaining the parameter information of the construction well; Well simulation; Writing rust removal construction design; Preparing the tools required for rust removal; Finishing the operation site; Implementing the rust removal work of the oil pipe inner wall; When the continuous scraping cutting module is lowered into the oil pipe, the straight scraping cutting gear is rolled against the oil pipe inner wall and drives the double-head gear shaft to rotate, so that the third upper joint and the third lower joint rotate relative to each other, so that the straight scraping cutting gear and the arc-shaped scraping cutting gear scrape around the oil pipe inner wall.

Description

Technical Field

[0001] This invention relates to the field of rust removal technology for the inner wall of oil pipes, and in particular to a device and process for rust removal of the inner wall of oil pipes using continuous tubing. Background Technology

[0002] In petroleum engineering operations, various casings, tubing, and drill pipes are frequently used tools on-site, and some of these pipes need to be reused. However, during use and storage, the surface of these pipes can oxidize and rust. The main reasons for this are: during use, repeated friction during tripping operations causes the anti-rust layer on the pipe surface to peel off, losing its protective function and leading to oxidation in the air; long-term immersion in high-temperature and high-pressure kill fluid causes the anti-rust layer on the inner and outer surfaces of the pipe to corrode and peel off, resulting in an oxidation reaction; and during storage, improper maintenance causes corrosion on the inner and outer surfaces of the pipe.

[0003] To ensure construction quality at the work site, it is necessary to remove rust from the inner walls of the tubing already installed in the well. Currently, the only way to clean the rust on the tubing is to clean it from the ground. Generally, a pipe gauge is used in conjunction with a sledgehammer to remove rust. This method is labor-intensive, slow, and has poor cleaning results. Therefore, there is an urgent need for a tool and process that can remove rust from tubing already installed in the well to ensure that the construction work is completed efficiently and with high quality at the work site. Summary of the Invention

[0004] This invention provides a device and process for removing rust from the inner wall of oil pipes using continuous tubing, in order to solve the problem that currently, rust removal of pipes can only be performed on the ground.

[0005] To alleviate the above-mentioned technical problems, the technical solution provided by the present invention is as follows:

[0006] A device for rust removal from the inner wall of a coiled tubing includes: an equal-diameter connector connected to the end of the coiled tubing; and a continuous scraping module connected to the equal-diameter connector. The continuous scraping module includes: a third upper connector; a third lower connector, rotatably mounted on the lower part of the third upper connector; a straight scraping gear, rotatably mounted on the third lower connector; a drive gear, rotatably mounted on the third lower connector and meshing with the straight scraping gear; and a double-headed gear shaft, rotatably mounted on both the third upper and third lower connectors, with the axis of the double-headed gear shaft aligned with both the third upper and third lower connectors. The axes of the heads are parallel; the arc-shaped scraping gear rotates at the middle of the lower connector; one end of the double-headed gear shaft is connected to a bevel gear that meshes with the drive gear, and the other end of the double-headed gear shaft is connected to a spur gear; the third upper connector is connected to an internal gear ring that meshes with the spur gear; when the continuous scraping module is lowered into the oil pipe, the straight scraping gear rolls against the inner wall of the oil pipe and drives the double-headed gear shaft to rotate, so that the third upper connector and the third lower connector rotate relative to each other, thereby the straight scraping gear and the arc-shaped scraping gear scrape around the inner wall of the oil pipe.

[0007] Furthermore, it also includes: a check valve connected to the equal-diameter connector; a safety connector connected to the check valve; and a rotating fine-scale brush module connected to the safety connector. The rotating fine-scale brush module includes: a second upper connector connected to the safety connector; a central tube integrally formed with the second upper connector and cylindrical in shape; a second lower connector connected to the bottom of the central tube; and a fine-scale brush cylinder sleeved onto the central tube. The fine-scale brush cylinder includes: a cylindrical body; bristles connected to the outer wall of the cylindrical body; two annular grooves formed on the outer wall of the cylindrical body; and a universal cavitation nozzle connected to one of them. Within one of the annular grooves; a directional impact nozzle, connected to another annular groove; an elliptical through hole, formed on the side wall of the central tube and connected to the universal cavitation nozzle and the directional impact nozzle; a portion of the liquid in the continuous oil pipe passes through the one-way valve, then through the safety joint, into the elliptical through hole on the central tube, into the annular groove of the cylinder, and is ejected through the universal cavitation nozzle to the inner wall of the oil pipe. Simultaneously, the liquid ejected from the directional impact nozzle generates a reverse force that drives the fine-grip brush cylinder to rotate, causing the brush bristles to scrape the inner wall of the oil pipe.

[0008] Furthermore, it also includes: a pulse-type rust removal module connected to the rotating fine brush module; the pulse-type rust removal module includes: a fourth upper connector connected to the third lower connector, and having a flow guiding cavity inside; a blade-type flow guide wheel rotating in the flow guiding cavity inside the fourth upper connector; a spherical spray head connected to the fourth upper connector; a flow guiding oblique hole is provided on the fourth upper connector; an intermittent liquid passage hole is provided inside the spherical spray head, a side drain hole is provided on the side wall of the spherical spray head, and a bottom drain hole is provided at the bottom of the spherical spray head; when another part of the liquid in the continuous oil pipe passes through the flow guiding oblique hole, it generates an oblique impact force to impact the blade-type flow guide wheel to rotate at high speed, and the rotating blade-type flow guide wheel intermittently blocks the intermittent liquid passage hole, so that the liquid intermittently enters the intermittent liquid passage hole and is pulsedly sprayed out from the side drain hole and the bottom drain hole to the inner wall of the oil pipe respectively.

[0009] Furthermore, a guide wheel shaft is connected inside the guide cavity of the upper connector, and the blade-type guide wheel rotates on the guide wheel shaft.

[0010] A rust removal process for the inner wall of an oil pipe, wherein the rust removal process employs a rust removal device and includes the following steps:

[0011] S1. Obtain parameter information for the construction well;

[0012] S2, Well Entry Simulation;

[0013] S3. Prepare the rust removal construction design;

[0014] S4. Prepare the tools needed for rust removal;

[0015] S5. Site preparation;

[0016] S6. Perform rust removal work on the inner wall of the oil pipe.

[0017] Furthermore, step S4 also includes:

[0018] S41. Prepare coiled tubing equipment with corresponding operating capacity according to the rust removal construction design requirements;

[0019] S42. Prepare well control devices such as blowout preventer boxes, blowout preventer tubing, blowout preventers, and reducing flanges that match the tubing tree;

[0020] S43. Determine the lifting equipment based on the height and maximum load of the coiled tubing wellhead injection head, blowout preventer box, blowout preventer pipe, blowout preventer, wellhead Christmas tree, etc.

[0021] S44. The coiled tubing depth counter should be calibrated before operation;

[0022] S45. Before operation, a chip catcher, throttling manifold, and ground filter should be prepared.

[0023] S46. Prepare pumping equipment and auxiliary devices according to design requirements;

[0024] S47. Prepare sufficient liquid storage tanks, metering tanks, and waste liquid storage tanks according to the operation and construction requirements;

[0025] S48. Prepare equal-diameter connection joints, rotary fine brush modules, continuous scraping modules, and pulse rust removal modules that meet the construction requirements.

[0026] S49. Prepare rust removal working fluid and adhesive with performance and quantity that meet the construction design requirements. The drag reduction rate of the rust removal working fluid shall not be less than 40%, and the viscosity of the adhesive shall not be less than 40 mPa·S.

[0027] Furthermore, step S6 also includes:

[0028] S61. Equipment placement, installation, and pressure testing;

[0029] S62, Connect toolchain;

[0030] S63. Rust removal work.

[0031] Furthermore, step S61 also includes:

[0032] S611. The placement, installation, and pressure testing of coiled tubing equipment shall comply with the requirements of relevant standards.

[0033] S612, connect the pumping equipment, surface high-pressure filter and coiled tubing roller in sequence, and test the pressure according to the well control design;

[0034] S613. Install the cuttings catcher, choke manifold, recovery line, and storage tank sequentially from the casing gate outwards, and test them according to the well control design.

[0035] Furthermore, step S62 also includes:

[0036] S621. Flush the coiled tubing with the working medium until the liquid properties at the inlet and outlet ends are consistent. Perform a ball test, and then connect the equal-diameter connector to the free end of the coiled tubing.

[0037] S622. Connect the test pressure plate to test the load on the connector. Gradually increase the tension. The tension should be greater than the working load of the safety connector when it is released from the hand. The connector is qualified if there is no slippage.

[0038] S623. Overall pressure test: The inlet pipeline, coiled tubing, equal diameter connection joints, etc. shall be pressure tested as a whole. The pressure test shall meet the requirements of the construction design.

[0039] S624, from top to bottom, is connected to an equal diameter connecting joint, a check valve, a safety joint, a rotating fine brush module, a continuous scraping module, and a pulse rust removal module;

[0040] S625. Start the pumping equipment, adjust the performance of each tool in the tool string according to different discharge rates, observe the working condition of each tool, and do not allow the tool string to be put into the well if it does not meet the requirements.

[0041] S626. Connect the blowout preventer to the wellhead blowout preventer and perform a pressure test on the entire blowout preventer system above the main gate valve of the tubing tree. The pressure test should meet the requirements of the construction design.

[0042] Furthermore, step S63 also includes:

[0043] S631. Reset the counter to zero and record the position of the bottom of the tool string when it is reset. Open the wellhead main valve and lower the coiled tubing.

[0044] S632. Slowly lower the coiled tubing;

[0045] S633. During normal lowering, a lifting and lowering test should be conducted every 300m, and the data should be recorded. The pump should be started for circulation from the moment the tool enters the well, and the return discharge rate should be 0.40m3 / min~0.45m3 / min.

[0046] S634. If an obstruction is encountered midway, the pressure shall not exceed 20kN. Record the depth of the obstruction location and the suspended weight value at the actual obstruction location. Then, slowly raise and lower the continuous tubing tool string at a speed not greater than 10m / min to 5m / min to remove rust.

[0047] S635. After rust removal is completed, circulate the well for more than 1.5 cycles and then pull the coiled tubing up to the wellhead.

[0048] S636. Confirm that the tool string is fully inserted into the blowout preventer and close the wellhead main valve.

[0049] S637. Confirm that the main valve at the wellhead is completely closed, depressurize the blowout preventer, remove the drill bit and grinding tools, and remove all equipment at the wellhead.

[0050] The beneficial effects of this invention are analyzed as follows:

[0051] A device for removing rust from the inner wall of a coiled tubing includes an equal-diameter connector connected to the end of the coiled tubing; a continuous scraping module connected to the equal-diameter connector; the continuous scraping module includes: a third upper connector; a third lower connector, fixedly rotatable at the lower part of the third upper connector; a straight scraping gear, fixedly rotatable within the third lower connector; a drive gear, fixedly rotatable within the third lower connector and meshing with the straight scraping gear; a double-ended gear shaft, fixedly rotatable within the third upper and third lower connectors, with the axis of the double-ended gear shaft parallel to the axes of the third upper and third lower connectors; and an arc-shaped scraping gear, fixedly rotatable at the middle part of the lower connector; one end of the double-ended gear shaft is connected to a bevel gear meshing with the drive gear, the other end of the double-ended gear shaft is connected to a spur gear, and an internal gear ring meshing with the spur gear is connected within the third upper connector.

[0052] The straight and curved scraping gears of the continuous scraping module penetrate the inner wall of the tubing. During lowering, the straight scraping gear rotates around its center axis under the action of the penetration force, which in turn drives the drive gear to rotate. The bevel gear of the double-headed gear shaft meshes with the bevel gear of the drive gear. Therefore, under the drive of the drive gear, through the transmission and change of the transmission direction by the double-headed gear shaft, the third lower connector rotates along the internal gear ring of the third upper connector, ensuring that the scraping of the inner wall of the tubing by the straight and curved scraping gears is carried out in a 360-degree manner without dead angles. Attached Figure Description

[0053] To more clearly illustrate the technical solutions in the specific embodiments or related technologies of the present invention, the drawings used in the description of the specific embodiments or related technologies will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0054] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0055] Figure 2 This is a full-section structural diagram of the equal-diameter connection joint of the present invention;

[0056] Figure 3 This is a schematic diagram of the structure of the continuous tubing connection core tube of the present invention;

[0057] Figure 4 This is a schematic diagram of a half-section of the outer shell of the continuous tubing connector of the present invention;

[0058] Figure 5 This is a half-section and top view schematic diagram of the sliding conical slip of the continuous tubing joint of the present invention;

[0059] Figure 6This is a half-section and top view schematic diagram of the continuous tubing joint wedge slider of the present invention;

[0060] Figure 7 This is a half-sectional structural diagram of the rotating fine brush module of the present invention;

[0061] Figure 8 This is a schematic diagram of a half-section of the central tube of the present invention;

[0062] Figure 9 This is a half-sectional structural diagram of the fine-grip brush cylinder of the present invention;

[0063] Figure 10 This is a schematic diagram of the full cross-section and top view of the universal cavitation nozzle of the present invention;

[0064] Figure 11 This is a schematic diagram of the full cross-section and top view of the directional impact nozzle of the present invention;

[0065] Figure 12 This is a schematic diagram of the half-section and top view of the spacer ring of the present invention;

[0066] Figure 13 This is a schematic diagram of the structure of the second lower connector of the present invention;

[0067] Figure 14 This is a schematic diagram of the full cross-sectional structure of the continuous scraping module of the present invention;

[0068] Figure 15 For the present invention Figure 14 Schematic diagram of the structure of AA;

[0069] Figure 16 For the present invention Figure 14 Schematic diagram of the structure of BB;

[0070] Figure 17 For the present invention Figure 14 A schematic diagram of the structure of CC;

[0071] Figure 18 For the present invention Figure 14 Schematic diagram of the structure of DD;

[0072] Figure 19 This is a schematic diagram of the structure of the third upper connector of the present invention;

[0073] Figure 20 This is a schematic diagram of the full cross-section and top view of the double-headed gear shaft of the present invention;

[0074] Figure 21 This is a schematic diagram of the full cross-section and left view of the drive gear of the present invention;

[0075] Figure 22 This is a full cross-section and left view schematic diagram of the arc-shaped scraping gear of the present invention;

[0076] Figure 23 This is a schematic diagram of the full cross-section and top view of the movable bushing of the present invention;

[0077] Figure 24 This is a schematic diagram of the full cross-sectional structure of the third lower connector of the present invention;

[0078] Figure 25 This is a schematic diagram of the full cross-sectional structure of the pulse-type rust removal head of the present invention;

[0079] Figure 26 For the present invention Figure 25 Schematic diagram of the structure of EE;

[0080] Figure 27 For the present invention Figure 25 Schematic diagram of the structure of FF;

[0081] Figure 28 This is a schematic diagram of the full cross-section and top view of the fourth upper connector of the present invention;

[0082] Figure 29 This is a schematic diagram of the full cross-section and top view of the blade-type guide vane of the present invention;

[0083] Figure 30 This is a schematic diagram of the full cross-section and top view of the spherical jet head of the present invention.

[0084] icon:

[0085] 100. Equal diameter connecting joint; 110. Coiled tubing connecting core tube; 111. Sealing section; 120. Joint housing; 121. Serrated structure; 122. Screw hole; 130. Coiled tubing joint sliding conical slip; 131. Small serrated structure; 132. Large serrated structure; 140. Coiled tubing joint wedge slider; 150. First lower joint; 200. Rotating fine brush module; 210. Second upper joint; 220. Center tube; 221. Elliptical through hole; 230. Fine brush cylinder; 231. Cylinder body; 2311. Directional nozzle seat; 2312. Universal nozzle seat; 232. Brush bristles; 233. Universal cavitation nozzle; 234. Directional impact nozzle; 240. Spacer ring; 250. Second lower joint; 300. Continuous scraping module; 310. Third upper joint; 311. Connecting bearing inner support; 312. Internal gear ring; 320, double-ended gear shaft; 330, drive gear; 340, straight scraping gear; 350, arc-shaped scraping gear; 360, support spring; 370, movable bushing; 380, rotating shaft; 390, third lower connector; 391, connecting bearing outer support; 392, mounting base; 393, first scraping gear seat; 394, second scraping gear seat; 395, spiral center channel; 400, pulse type Rust removal module; 410, fourth upper connector; 411, upper internal thread; 412, internal guide oblique hole; 413, guide cavity; 414, guide wheel shaft; 415, lower external thread; 420, blade-type guide wheel; 430, spherical spray head; 431, upper thread; 432, interlocking liquid passage hole; 433, guide wheel groove; 434, internal partition; 435, side drain hole; 436, bottom drain hole. Detailed Implementation

[0086] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0087] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0088] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0089] Example 1

[0090] like Figures 1-30 As shown, a rust removal device for the inner wall of a coiled tubing includes: an equal-diameter connecting joint 100 connected to the end of the coiled tubing; a continuous scraping module 300 connected to the equal-diameter connecting joint; the continuous scraping module 300 includes: a third upper joint 310; a third lower joint 390 rotatably mounted on the lower part of the third upper joint 310; a straight scraping gear 340 rotatably mounted on the third lower joint 390; a drive gear 330 rotatably mounted on the third lower joint 390 and meshing with the straight scraping gear 340; and a double-headed gear shaft 320 rotatably mounted on the third upper joint 310 and the third lower joint 390, with the axis of the double-headed gear shaft 320 being perpendicular to the axis of the third upper joint 310. The axes of the head 310 and the third lower connector 390 are parallel; the arc-shaped scraping gear 350 is fixed and rotates in the middle of the lower connector; one end of the double-headed gear shaft 320 is connected to a bevel gear that meshes with the drive gear 330, and the other end of the double-headed gear shaft 320 is connected to a spur gear; the third upper connector 310 is connected to an internal gear ring 312 that meshes with the spur gear; when the continuous scraping module 300 is lowered into the oil pipe, the straight scraping gear 340 rolls against the inner wall of the oil pipe and drives the double-headed gear shaft 320 to rotate, so that the third upper connector 310 and the third lower connector 390 rotate relative to each other, thereby the straight scraping gear 340 and the arc-shaped scraping gear 350 scrape around the inner wall of the oil pipe.

[0091] The working mechanism of the rust removal device provided in this embodiment is as follows:

[0092] The straight scraping gear 340 and the arc-shaped scraping gear 350 of the continuous scraping module 300 are inserted into the inner wall of the tube column. When lowered, the straight scraping gear 340 rotates around its center axis under the action of the insertion force, which drives the drive gear 330 to rotate at the same time. The bevel gear of the double-headed gear shaft 320 meshes with the bevel gear of the drive gear 330. Therefore, under the drive of the drive gear 330, through the transmission and change of the transmission direction by the double-headed gear shaft 320, the third lower connector 390 rotates along the internal gear ring 312 of the third upper connector 310, ensuring that the scraping of the inner wall of the tube column by the straight scraping gear 340 and the arc-shaped scraping gear 350 is carried out in a 360-degree manner without dead angles.

[0093] The third upper connector 310 has a cylindrical structure. The upper end is machined with an internal thread that mates with the second lower connector 250. The lower end is a connecting bearing inner support 311, which, together with the upper outer support of the third lower connector 390, supports the connecting bearing. Inside the third upper connector 310, near the connecting bearing inner support 311, an internal gear ring 312 is machined to mate with the upper spur gear of the double-ended gear shaft 320. The double-ended gear shaft 320 has a dumbbell-shaped cylindrical structure. One end is a spur gear that mates with the internal gear ring 312 of the third upper connector 310, and the other end is a bevel gear that mates with the drive gear 330. A fixed shaft in the middle fixes the double-ended gear shaft 320 to the fixed seat of the third lower connector 390. The drive gear 330 is a flat round shape with a central through hole. The columnar structure has a bevel gear machined at one end to mesh with the bevel gear of the double-ended gear shaft 320, and a spur gear machined on the outer wall of the other end to mesh with the straight scraping gear 340. The straight scraping gear 340 is a chess piece-shaped structure with a central through hole, and spur gears are machined on its edges to mesh with the spur gears of the drive gear 330. Simultaneously, the edge spur gears, under the action of the support spring 360, are pressed tightly against the inner wall of the column and penetrate the rust layer. The hardness of the spur gears is used to cut and scrape the rust on the inner wall of the column. The arc-shaped scraping gear 350 is similar to the straight scraping gear 340, except that its edges are machined to fit the arc surface of the inner wall of the column, ensuring a tighter fit during cutting and scraping, thus improving the rust removal effect. The support spring 360 is a spring with a certain elasticity. One end is fixed to the spring seat, and the other end is fixed to the movable bushing 370 of the straight scraping gear 340, so that the straight scraping gear 340 can move within a certain range under the action of the support spring 360, and provide a certain elastic force for the straight scraping gear 340 to enter the inner wall of the tubular column. The movable bushing 370 is racket-shaped, and a shaft hole that matches the rotating shaft 380 is machined at the center of its racket net. The length and diameter of the racket handle can be machined according to the inner diameter of the support spring 360 to ensure that the support spring 360 can be fitted in. The rotating shaft 380 is a cylindrical structure, and its length must be able to pass through the central through hole of the straight scraping gear 340 and the central through holes of the two movable bushings 370 at the same time. Snap ring grooves are machined at both ends for placing the limiting snap rings. The third lower connector 390 The structure is cylindrical and mainly consists of a connecting bearing outer support 391, a mounting base 392, a first scraping gear seat 393, a second scraping gear seat 394, a helical central channel 395, and a lower connecting thread. The connecting bearing outer support 391 has a step machined at the uppermost end of the third lower connector 390 to accommodate the bearing, and it mates with the connecting bearing inner support 311 of the third upper connector 310 to connect and fix the bearing, allowing the third upper connector 310 and the third lower connector 390 to rotate relative to each other. The mounting base 392 has a groove machined in the inner cavity of the third lower connector 390 to accommodate the drive gear 330, and a pin hole is machined at the position corresponding to the central axis of the drive gear 330. The size of the groove ensures that the drive gear 330 can rotate freely.The inner end of the first scraping gear seat 393 communicates with the mounting base 392, and the outer end penetrates the body. Its width can be determined according to the width of the straight scraping gear 340. Rounded rectangular grooves are machined on both sides of the central axis position. The height of the grooves is equal to the diameter of the central axis of the straight scraping gear 340, and the width is greater than the diameter of the central axis of the straight scraping gear 340 to ensure that the central axis can move within the rounded rectangular grooves. A columnar groove for placing the supporting spring 360 and a base for fixing the spring are machined on one side. The second scraping gear seat 394 is similar to the first scraping gear seat 393, except that the first scraping gear seat 393 only has a single-sided columnar groove supporting the spring 360, while the second scraping gear seat 394 has columnar grooves on both sides. The spiral central channel 395 consists of several spiral through holes machined inside the third lower connector 390 to ensure normal liquid flow. The number and diameter of these holes can be determined based on the internal space of the third lower connector 390. The lower connecting thread is a male thread that connects to the fourth upper connector 410.

[0094] Regarding the structure of the rotating fine brush module 200, specifically:

[0095] It also includes: a check valve connected to the equal-diameter connector 100; a safety connector connected to the check valve; a rotating fine brush module 200 connected to the safety connector; the rotating fine brush module 200 includes: a second upper connector 210 connected to the safety connector; a central tube 220 integrally formed with the second upper connector 210 and cylindrical in shape; a second lower connector 250 connected to the bottom of the central tube 220; a fine brush cylinder 230 sleeved on the central tube 220; the fine brush cylinder 230 includes: a cylinder body 231; bristles 232 connected to the outer wall of the cylinder body 231; two annular grooves formed on the outer wall of the cylinder body 231; and a universal cavitation nozzle. 233 is connected to one of the annular grooves; directional impact nozzle 234 is connected to the other annular groove; elliptical through hole 221 is opened on the side wall of the central tube 220 and is connected to the universal cavitation nozzle 233 and the directional impact nozzle 234; a part of the liquid in the continuous oil pipe passes through the one-way valve and then through the safety joint into the elliptical through hole 221 on the central tube 220 and enters the annular groove of the cylinder 231, and is sprayed out to the inner wall of the oil pipe through the universal cavitation nozzle 233. At the same time, the liquid sprayed out from the directional impact nozzle 234 generates a reverse force to drive the fine brush cylinder 230 to rotate, so that the bristles 232 scrape the inner wall of the oil pipe.

[0096] The coiled tubing connecting core tube 110 is a cylinder with a variable outer diameter. The coiled tubing and the connector housing 120 are respectively slidably fitted onto the coiled tubing connecting core tube 110. The coiled tubing connector sliding conical slip 130 is located in the cavity between the coiled tubing and the connector housing 120, locking the two together. The coiled tubing connector wedge-shaped slider 140 is located between the connector housing 120 and the coiled tubing connecting core tube 110. One end of the coiled tubing connector wedge-shaped slider 140 is wedged into the wedge gap between the coiled tubing and the coiled tubing connecting core tube 110, and the other end of the coiled tubing connector wedge-shaped slider 140 abuts against the connector coiled tubing screw inserted into the connector housing 120. The upper coiled tubing... The connecting tube 110 is a cylindrical structure. A sealing section 111, with an outer diameter slightly larger than the inner diameter of the coiled tubing, is machined on its left outer wall. The sealing section 111 of the coiled tubing connecting tube 110 is an interference fit. Six annular sealing grooves and three clamping grooves are machined on the sealing section 111 of the coiled tubing connecting tube 110. From the left to the right end of the sealing section 111, the three annular sealing grooves and three clamping grooves are alternately distributed, while the other three annular sealing grooves are continuously distributed. The middle part of the coiled tubing connecting tube 110 is a groove, the outer diameter of which is the same as the inner diameter of the coiled tubing cut body. The right end of the coiled tubing connecting tube 110 is a section... A cylinder with a diameter larger than the outer diameter of the groove has two annular sealing grooves machined at its left end for installing O-rings, and external threads machined at its right end. The outer diameter of the connector housing 120 is the same as the outer diameter of the equal-diameter connecting connector 100, and the two are coaxial. A serrated structure 121 is machined at the left end of the inner wall of the connector housing 120. The middle part of the inner wall of the connector housing 120 is a groove, and first and second steps are machined on the right side of the groove. Viewed from left to right, the inner diameter of the first step is smaller than the inner diameter of the groove and is a cylindrical surface. A screw hole 122 is machined at the left end of the first step for installing the upper connector continuous tubing screw. The inner diameter of the second step is smaller than the inner diameter of the first step. The wall is machined with an internal thread, which mates with the external thread on the outer wall of the coiled tubing connecting core tube 110. The coiled tubing joint sliding conical slip 130 is a cylindrical structure. Small serrations 131 are machined on the inner wall of the coiled tubing joint sliding conical slip 130, and large serrations 132, opposite to the small serrations 131, are machined on the outer wall of the coiled tubing joint sliding conical slip 130. The coiled tubing joint sliding conical slip 130 is located inside the cavity between the joint housing 120 and the coiled tubing. The large serrations 132 on the outer wall of the coiled tubing joint sliding conical slip 130 mate with the serrations 121 on the left end of the inner wall of the joint housing 120.The small serrated structure 131 on the inner wall of the sliding conical slip 130 of the coiled tubing connector clamps against the outer wall of the coiled tubing cutter, increasing the frictional resistance between the coiled tubing connector and the coiled tubing cutter. The inner diameter of the wedge-shaped slider 140 of the coiled tubing connector is the same as the outer diameter at the groove of the upper coiled tubing connecting core tube 110. The outer wall of the left end of the upper coiled tubing connector wedge-shaped slider 140 is machined into a conical surface with a smaller outer diameter on the left and a larger outer diameter on the right. The outer wall of the right end of the upper coiled tubing connector wedge-shaped slider 140 is a cylindrical surface. The coiled tubing connector wedge-shaped slider 140 is formed by combining two semi-rings with the same structure. One end of the semi-ring has a double clamping structure, and the other end has a single clamping structure. The single clamping structure of the half ring engages with the double clamping structure of the other half ring to form a complete ring continuous tubing connector wedge slider 140, which is located between the connector housing 120 and the continuous tubing connecting core tube 110. The right end of the continuous tubing connector wedge slider 140 abuts against the connector continuous tubing screw, and the left end of the continuous tubing connector wedge slider 140 is wedged between the continuous tubing and the continuous tubing connecting core tube 110. The continuous tubing connector wedge slider 140 provides extrusion force to the end of the continuous tubing. The first lower connector 150 has a male thread machined at the lower end of the continuous tubing connector wedge slider 140 to connect with the second upper connector 210.

[0097] The second upper connector 210 has an internal thread machined on the upper part of the rotating brush module 200 to mate with the first lower connector 150. The central tube 220 and the second upper connector 210 are integral hollow cylindrical structures. A limiting step is machined on the lower part of the second upper connector 210 to restrict the brush cylinder 230. The diameter of the part below the limiting step is smaller than the inner diameter of the brush cylinder 230. An elliptical through hole 221 is opened at the position corresponding to the nozzle on the brush cylinder 230 to make it communicate with the inside. At the lowest end of the central tube 220, a thread is machined to mate with the second lower connector 210. The 50-gauge matching external thread, the fine-gauge brush cylinder 230 is in pairs, separated by spacer rings 240, and is fitted onto the central tube 220. It mainly consists of a cylinder body 231, bristles 232, universal cavitation nozzles 233, and directional impact nozzles 234. The cylinder body 231 is a cylindrical structure with a certain thickness and length, and its inner diameter is slightly larger than the outer diameter of the central tube 220. Two rectangular annular concave grooves are machined on its inner wall at positions corresponding to the through hole of the central tube 220. Four through directional nozzles with a certain angle are evenly arranged on the circumference of the upper groove. Nozzle holder 2311 is used to install directional impact nozzle 234. Four universal nozzle holders 2312 are evenly arranged circumferentially in the lower groove for installing universal cavitation nozzles. Brush 232 consists of short steel wires of a certain length embedded in the outer wall of the cylinder 231 where there are no universal cavitation nozzles or directional impact nozzles 234. These wires are embedded a certain length into the outer wall of the cylinder 231 and exposed a certain length, forming a spiral arrangement. A certain gap is left between each row to allow for the flow of liquid containing iron filings, preventing pressure buildup and blockage. Universal cavitation spray... The nozzle 233 is a spherical shape with a limiting shoulder. A through hole with a certain angle is machined inside the center of the spherical surface perpendicular to the limiting shoulder. The directional impact nozzle 234 is a flat cylindrical shape with a flared through hole machined inside, which is larger at one end and smaller at the other. The spacer ring 240 is a circular ring with a certain thickness and width that is fitted on the central tube 220. Its inner diameter is larger than the outer diameter of the central tube 220, and its outer diameter is the same as the outer diameter of the steel body of the brush cylinder 230. The second lower connector 250 has an internal thread at the top that connects to the central tube 220, and a male thread at the bottom that connects to the third upper connector 310.

[0098] Regarding the structure of the pulse rust removal module 400, specifically:

[0099] It also includes: a pulse rust removal module 400, connected to the rotating fine brush module 200; the pulse rust removal module 400 includes: a fourth upper connector 410, connected to the third lower connector 390, and having a guide cavity 413 inside; a blade-type guide wheel 420, rotating within the guide cavity 413 inside the fourth upper connector 410; a spherical spray head 430, connected to the fourth upper connector 410; the fourth upper connector 410 has a guide oblique hole; the spherical spray head 430 has an inter-channel inside. The spherical nozzle 430 has a side drain hole 435 on its side wall and a bottom drain hole 436 at its bottom. When another part of the liquid in the continuous tubing passes through the guide orifice, it generates an oblique impact force that impacts the blade-type guide wheel 420 to rotate at high speed. The rotating blade-type guide wheel intermittently blocks the intermittent liquid passage 432, causing the liquid to intermittently enter the intermittent liquid passage 432 and be pulsedly ejected from the side drain hole 435 and the bottom drain hole 436 to the inner wall of the tubing.

[0100] The fourth upper connector 410 is a cylindrical structure mainly composed of an upper internal thread 411, an internal guide oblique hole 412, a guide cavity 413, a guide wheel shaft 414, and a lower external thread 415. The upper internal thread 411 is an internal thread machined at the upper end of the fourth upper connector 410 to mate with the third lower connector 390. The internal guide oblique hole 412 is a series of circularly arranged, inclined through square holes machined on the bottom plane of the upper internal thread 411 inside the fourth upper connector 410, allowing liquid to pass through the oblique holes and enter the guide cavity 413 at a certain spray angle. The guide cavity 413 is a cavity with a certain depth machined inside the lower end of the fourth upper connector 410. The size of the annular cavity can be determined according to the size of the blade-type guide wheel 420, ensuring that the blade-type guide wheel 420 can rotate freely inside it. Simultaneously, its bottom is connected to the internal guide oblique hole 412. The guide wheel shaft 414 is a shaft with a central opening within the guide cavity 413 for fixing the blade-type guide wheel 420. Its diameter can be determined according to the central shaft hole of the blade-type guide wheel 420. The lower external thread 415 is an external thread machined on the outer wall of the other end of the fourth upper connector 410 to mate with the upper thread 431 of the spherical spray head 430. The blade-type guide wheel 420 is a structure with several blades at a certain angle and a central shaft hole, and has a certain thickness. The spherical jet head 430 is a flat cylindrical shape with a central shaft hole machined in its center. It fits onto the guide wheel shaft 414 to ensure free rotation. The spherical jet head 430 has a hemispherical structure and mainly includes an upper thread 431, alternating liquid passage holes 432, a guide wheel groove 433, an internal partition 434, side drain holes 435, and a bottom drain hole 436. The upper thread 431 is an internal thread machined on the upper part of the spherical jet head 430 to mate with the lower external thread 415. The alternating liquid passage holes 432 are circularly arranged through holes machined inside the spherical jet head 430, with two spaced-apart through holes leading to the side drain hole 435 and the bottom drain hole 436 respectively. When the blade-type guide wheel 420 rotates, it will... The inter-channel liquid hole 432 experiences periodic blockage, generating pulsed shock waves. The guide wheel groove 433 is a cylindrical groove machined at the center of the inter-channel liquid hole 432, and its diameter can be determined according to the size of the guide wheel shaft 414. The internal partition 434 is a transverse partition machined inside the spherical nozzle 430, separating the side drain hole 435 and the bottom drain hole 436 from each other. The side drain hole 435 has several connecting holes machined on the side wall of the spherical nozzle 430, which are connected to a portion of the inter-channel liquid hole 432. The bottom drain hole 436 has several connecting holes machined at the bottom semicircle of the spherical nozzle 430, which are connected to another portion of the inter-channel liquid hole 432.

[0101] Example 2

[0102] A rust removal process for the inner wall of an oil pipe, which uses the rust removal device described in Example 1, includes the following steps:

[0103] S1. Obtain parameter information for the construction well;

[0104] S2, Well Entry Simulation;

[0105] S3. Prepare the rust removal construction design;

[0106] S4. Prepare the tools needed for rust removal;

[0107] S5. Site preparation;

[0108] S6. Perform rust removal work on the inner wall of the oil pipe.

[0109] The parameter information to be obtained in step S1 includes: well type, casing specifications, casing damage status, and wellhead tree specifications; well inclination data; formation pressure coefficient, temperature, and fluid properties; current wellhead pressure, production capacity, and leakage status; original production zone, debris in the well, and previous operational measures; and current tubing string structure.

[0110] Step S2, the wellbore entry simulation, specifically involves: simulating the wellbore trajectory using software based on wellbore structure, well inclination data, and production casing parameters; inputting coiled tubing parameters that meet the requirements of SY / T6895, inputting working fluid parameters and tool string data, and performing a coiled tubing entry simulation. Based on the simulation results, the following steps are taken: If the simulation results show that the coiled tubing can be run to the bottom of the tubing string, record the normal lowering and lifting of the suspended weight; if the simulation results show that the coiled tubing cannot be run to the bottom of the tubing string, add a hydraulic oscillator to the coiled tubing, or use a metal drag reducer, or both simultaneously, and continue the simulation until the simulation results show that the coiled tubing can be run to the bottom of the tubing string. Record the normal lowering and lifting of the suspended weight. If the results still show that it cannot be run to the bottom of the tubing string, replace the coiled tubing with a different size for simulation.

[0111] Step S3, which involves writing the rust removal construction design, includes: writing the coiled tubing rust removal construction design based on the oil test geological design, oil test engineering design, and well simulation results. The coiled tubing rust removal construction design should include detailed construction steps, operation requirements, and material preparation, and refine and improve quality, well control, and environmental protection requirements. The coiled tubing rust removal construction design should be revised simultaneously with any changes to the oil test geological design or oil test engineering design.

[0112] Step S5 involves preparing the work site, including: surveying the road leading to the well site to ensure smooth passage for coiled tubing installation vehicles; leveling the well site to ensure it can support the construction equipment and that there is sufficient working space around the wellhead; and ensuring that the work site has the conditions for venting and testing, and meets the requirements for venting and ignition.

[0113] Further details regarding preparing the tools needed for rust removal in step S4 include:

[0114] S41. Prepare coiled tubing equipment with corresponding operating capacity according to the rust removal construction design requirements;

[0115] S42. Prepare well control devices such as blowout preventer boxes, blowout preventer tubing, blowout preventers, and reducing flanges that match the tubing tree;

[0116] S43. Determine the lifting equipment based on the height and maximum load of the coiled tubing wellhead injection head, blowout preventer box, blowout preventer pipe, blowout preventer, wellhead Christmas tree, etc.

[0117] S44. The coiled tubing depth counter should be calibrated before operation;

[0118] S45. Before operation, a chip catcher, throttling manifold, and ground filter should be prepared.

[0119] S46. Prepare pumping equipment and auxiliary devices according to design requirements;

[0120] S47. Prepare sufficient liquid storage tanks, metering tanks, and waste liquid storage tanks according to the operation and construction requirements;

[0121] S48. Prepare equal-diameter connection joints 100, rotating fine brush module 200, continuous scraping module 300 and pulse rust removal module 400 that meet the construction requirements.

[0122] S49. Prepare rust removal working fluid and adhesive with performance and quantity that meet the construction design requirements. The drag reduction rate of the rust removal working fluid shall not be less than 40%, and the viscosity of the adhesive shall not be less than 40 mPa·S.

[0123] Regarding step S6, which involves rust removal from the inner wall of the oil pipe, further steps include:

[0124] S61. Equipment placement, installation, and pressure testing;

[0125] S62, Connect toolchain;

[0126] S63. Rust removal work.

[0127] Further details regarding step S61, equipment placement, installation, and pressure testing, include:

[0128] S611. The placement, installation, and pressure testing of coiled tubing equipment shall comply with the requirements of relevant standards.

[0129] S612, connect the pumping equipment, surface high-pressure filter and coiled tubing roller in sequence, and test the pressure according to the well control design;

[0130] S613. Install the cuttings catcher, choke manifold, recovery line, and storage tank sequentially from the casing gate outwards, and test them according to the well control design.

[0131] Further details regarding step S62, connecting the toolchain, include:

[0132] S621. Flush the coiled tubing with the working medium until the liquid properties at the inlet and outlet ends are consistent. Perform a ball test, and then connect the equal diameter connector 100 to the free end of the coiled tubing.

[0133] S622. Connect the test pressure plate to test the load on the connector. Gradually increase the tension. The tension should be greater than the working load of the safety connector when it is released from the hand. The connector is qualified if there is no slippage.

[0134] S623. Overall pressure test: The inlet pipeline, coiled tubing, equal diameter connection joints 100, etc. shall be pressure tested as a whole. The pressure test shall meet the requirements of the construction design.

[0135] S624, from top to bottom, are connected to equal diameter connecting joint 100, check valve, safety joint, rotating fine brush module 200, continuous scraping module 300 and pulse rust removal module 400.

[0136] S625. Start the pumping equipment, adjust the performance of each tool in the tool string according to different discharge rates, observe the working condition of each tool, and do not allow the tool string to be put into the well if it does not meet the requirements.

[0137] S626. Connect the blowout preventer to the wellhead blowout preventer and perform a pressure test on the entire blowout preventer system above the main gate valve of the tubing tree. The pressure test should meet the requirements of the construction design.

[0138] Further details regarding step S63, the rust removal process, include:

[0139] S631. Reset the counter to zero and record the position of the bottom of the tool string when it is reset. Open the wellhead main valve and lower the coiled tubing.

[0140] S632. Slowly lower the coiled tubing;

[0141] S633. During normal lowering, a lifting and lowering test should be conducted every 300m, and the data should be recorded. The pump should be started for circulation from the moment the tool enters the well, and the return discharge rate should be 0.40m3 / min~0.45m3 / min.

[0142] S634. If an obstruction is encountered midway, the pressure shall not exceed 20kN. Record the depth of the obstruction location and the suspended weight value at the actual obstruction location. Then, slowly raise and lower the continuous tubing tool string at a speed not greater than 10m / min to 5m / min to remove rust.

[0143] S635. After rust removal is completed, circulate the well for more than 1.5 cycles and then pull the coiled tubing up to the wellhead.

[0144] S636. Confirm that the tool string is fully inserted into the blowout preventer and close the wellhead main valve.

[0145] S637. Confirm that the main valve at the wellhead is completely closed, depressurize the blowout preventer, remove the drill bit and grinding tools, and remove all equipment at the wellhead.

[0146] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A device for removing rust from the inner wall of an oil pipe using continuous tubing, characterized in that... ； Includes: an equal-diameter connecting joint (100), connected to the end of the coiled tubing; A continuous scraping module (300) is connected to the equal-diameter connector; The continuous scraping module (300) includes: Third upper connector (310); The third lower connector (390) is fixedly rotatable at the lower part of the third upper connector (310); The straight scraping gear (340) rotates on a fixed axis within the third lower connector (390); The drive gear (330) rotates on a fixed axis within the third lower connector (390) and meshes with the straight scraping gear (340); The double-headed gear shaft (320) rotates within the third upper connector (310) and the third lower connector (390) with its axis fixed, and the axis of the double-headed gear shaft (320) is parallel to the axis of the third upper connector (310) and the third lower connector (390). The arc-shaped scraping gear (350) rotates on a fixed axis at the middle of the lower connector; One end of the double-ended gear shaft (320) is connected to a bevel gear that meshes with the drive gear (330), and the other end of the double-ended gear shaft (320) is connected to a spur gear. The third upper connector (310) is internally connected to an internal gear ring (312) that meshes with the spur gear. When the continuous scraping module (300) is lowered into the oil pipe, the straight scraping gear (340) rolls against the inner wall of the oil pipe and drives the double-headed gear shaft (320) to rotate, so that the third upper connector (310) and the third lower connector (390) rotate relative to each other, thereby the straight scraping gear (340) and the arc-shaped scraping gear (350) scrape around the inner wall of the oil pipe; Also includes: A check valve is connected to the equal-diameter connecting joint (100). A safety connector is attached to the check valve. A rotating precision brush module (200) is connected to the safety connector; The rotating fine-scale brush module (200) includes: The second upper connector (210) is connected to the safety connector; The central tube (220) is integrally formed with the second upper connector (210) and is cylindrical; The second lower connector (250) is connected to the bottom of the central tube (220); A fine-grip brush tube (230) is fitted onto the central tube (220). The fine-grip brush tube (230) includes: Cylinder (231); Brush bristles (232) are attached to the outer wall of the cylinder (231); Two annular grooves are formed on the outer wall of the cylinder (231); The universal cavitation nozzle (233) is connected to one of the annular grooves; A directional impact nozzle (234) is connected to another of the aforementioned annular grooves; An elliptical through hole (221) is formed on the side wall of the central tube (220) and is connected to the universal cavitation nozzle (233) and the directional impact nozzle (234); A portion of the liquid in the continuous tubing passes through the one-way valve and then through the safety connector into the elliptical through hole (221) on the central tube (220), entering the annular groove of the cylinder (231), and is ejected through the universal cavitation nozzle (233) to the inner wall of the tubing. At the same time, it is ejected from the directional impact nozzle (234) to generate a reverse force, which drives the fine brush cylinder (230) to rotate, causing the brush bristles (232) to scrape the inner wall of the tubing.

2. The rust removal device for the inner wall of a tubing using a continuous tubing as described in claim 1, characterized in that... ； Also includes: A pulse-type rust removal module (400) is connected to the rotating fine brush module (200). The pulse-type rust removal module (400) includes: The fourth upper connector (410) is connected to the third lower connector (390) and has a flow guide cavity (413) inside. A blade-type guide vane (420) rotates within the guide cavity (413) inside the fourth upper connector (410). A spherical nozzle (430) is connected to the fourth upper connector (410). The fourth upper connector (410) is provided with a flow guide oblique hole; The spherical nozzle (430) has an interlocking liquid passage hole (432) inside, a side drain hole (435) on the side wall of the spherical nozzle (430), and a bottom drain hole (436) at the bottom of the spherical nozzle (430). Another portion of the liquid in the continuous tubing generates an oblique impact force when it passes through the guide orifice, causing the blade-type guide wheel (420) to rotate at high speed. The rotating blade-type guide wheel intermittently blocks the intermittent liquid passage (432), causing the liquid to intermittently enter the intermittent liquid passage (432) and be pulsedly ejected from the side drain hole (435) and the bottom drain hole (436) to the inner wall of the tubing.

3. The rust removal device for the inner wall of a tubing using a continuous tubing as described in claim 2, characterized in that; The upper connector has a guide wheel shaft (414) connected inside the guide cavity (413), and the blade-type guide wheel (420) rotates on the guide wheel shaft (414).

4. A rust removal process for the inner wall of an oil pipe, wherein the rust removal process employs the rust removal device as described in any one of claims 1-3, characterized in that, Includes the following steps: S1. Obtain parameter information for the construction well; S2, Well Entry Simulation; S3. Prepare the rust removal construction design; S4. Prepare the tools needed for rust removal; S5. Site preparation; S6. Perform rust removal work on the inner wall of the oil pipe.

5. The rust removal process for the inner wall of the oil pipe according to claim 4, characterized in that... ； Step S4 also includes: S41. Prepare coiled tubing equipment with corresponding operating capacity according to the rust removal construction design requirements; S42. Prepare well control devices such as blowout preventer boxes, blowout preventer tubing, blowout preventers, and reducing flanges that match the tubing tree; S43. Determine the lifting equipment based on the height and maximum load of the coiled tubing wellhead injection head, blowout preventer box, blowout preventer pipe, blowout preventer, wellhead Christmas tree, etc. S44. The coiled tubing depth counter should be calibrated before operation; S45. Before operation, a chip catcher, throttling manifold, and ground filter should be prepared. S46. Prepare pumping equipment and auxiliary devices according to design requirements; S47. Prepare sufficient liquid storage tanks, metering tanks, and waste liquid storage tanks according to the operation and construction requirements; S48. Prepare equal-diameter connection joints (100), rotating fine brush module (200), continuous scraping module (300) and pulse rust removal module (400) that meet the construction requirements. S49. Prepare rust removal working fluid and adhesive with performance and quantity that meet the construction design requirements. The drag reduction rate of the rust removal working fluid shall not be less than 40%, and the viscosity of the adhesive shall not be less than 40 mPa·S.

6. The rust removal process for the inner wall of the oil pipe according to claim 4, characterized in that... ； Step S6 also includes: S61. Equipment placement, installation, and pressure testing; S62, Connect toolchain; S63. Rust removal work.

7. The rust removal process for the inner wall of the oil pipe according to claim 6, characterized in that... ； Step S61 also includes: S611. The placement, installation, and pressure testing of coiled tubing equipment shall comply with the requirements of relevant standards. S612, connect the pumping equipment, surface high-pressure filter and coiled tubing roller in sequence, and test the pressure according to the well control design; S613. Install the cuttings catcher, choke manifold, recovery line, and storage tank sequentially from the casing gate outwards, and test them according to the well control design.

8. The rust removal process for the inner wall of the oil pipe according to claim 6, characterized in that... ； Step S62 also includes: S621. Flush the coiled tubing with the working medium until the liquid properties at the inlet and outlet ends are consistent. Perform a ball test and then connect the equal diameter connector (100) to the free end of the coiled tubing. S622. Connect the test pressure plate to test the load on the connector. Gradually increase the tension. The tension should be greater than the working load of the safety connector when it is released from the hand. The connector is qualified if there is no slippage. S623. Overall pressure test: The inlet pipeline, coiled tubing, equal diameter connection joint (100), etc. shall be pressure tested as a whole. The pressure test shall meet the requirements of the construction design. S624, from top to bottom, are connected the equal diameter connecting joint (100), check valve, safety joint, rotating fine brush module (200), continuous scraping module (300) and pulse rust removal module (400). S625. Start the pumping equipment, adjust the performance of each tool in the tool string according to different discharge rates, observe the working condition of each tool, and do not allow the tool string to be put into the well if it does not meet the requirements. S626. Connect the blowout preventer to the wellhead blowout preventer and perform a pressure test on the entire blowout preventer system above the main gate valve of the tubing tree. The pressure test should meet the requirements of the construction design.

9. The rust removal process for the inner wall of the oil pipe according to claim 6, characterized in that... ； Step S63 also includes: S631. Reset the counter to zero and record the position of the bottom of the tool string when it is reset. Open the wellhead main valve and lower the coiled tubing. S632. Slowly lower the coiled tubing; S633. During normal lowering, a lifting and lowering test should be conducted every 300m, and the data should be recorded. The pump should be started for circulation from the moment the tool enters the well, and the return discharge rate should be 0.40m3 / min~0.45m3 / min. S634. If an obstruction is encountered midway, the pressure shall not exceed 20kN. Record the depth of the obstruction location and the suspended weight value at the actual obstruction location. Then, slowly raise and lower the continuous tubing tool string at a speed not greater than 10m / min to 5m / min to remove rust. S635. After rust removal is completed, circulate the well for more than 1.5 cycles and then pull the coiled tubing up to the wellhead. S636. Confirm that the tool string is fully inserted into the blowout preventer and close the wellhead main valve. S637. Confirm that the main valve at the wellhead is completely closed, depressurize the blowout preventer, remove the drill bit and grinding tools, and remove all equipment at the wellhead.

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