A hydraulic jetting device and method for treating casing-damaged wells.

Abstract

This invention relates to the field of oilfield casing damage well repair technology, and in particular to a hydraulic jetting device and method for treating casing damage wells. The hydraulic jetting device for treating casing damage wells includes an upper tube, a lower tube, a clamp, a top tube, and coiled tubing. The lower tube is coaxial with the upper tube and threadedly connected. The clamp slides inside the lower tube and has multiple spiral grooves on its circumference, arranged circumferentially to give the clamp radial contraction capability. The projections of adjacent grooves in the axial direction of the clamp overlap. The top tube is fitted inside the upper tube and has a conical inner wall. The top tube is fitted outside the clamp, and the coiled tubing is fitted inside the clamp. Tightening the upper and lower tubes causes the conical surface of the top tube to push the clamp to contract and hold the coiled tubing. The spiral grooves ensure that the clamping force of the clamp is continuously distributed circumferentially around the coiled tubing, preventing interruptions and effectively preventing flattening, deformation, or damage caused by localized stress concentration in the coiled tubing, thus ensuring safe and energy-efficient downhole operations.

Description

Technical Field

[0001] This invention relates to the field of oilfield casing damage repair technology, and in particular to a hydraulic jetting device and method for treating casing damage wells. Background Technology

[0002] During oil and gas extraction, some oil and water wells, under long-term operation, are affected by various factors such as geological changes, equipment wear, and external impacts, resulting in casing deformation, breakage, and fracture. These wells with casing damage are called damaged wells. Damaged wells are often accompanied by debris blockage, leading to wellbore obstruction and severely hindering normal oil and gas extraction operations. Among these, the complex well condition of "fracture + debris" is particularly difficult to handle. Traditional mechanical processing methods are cumbersome, inefficient, and lack efficient, non-contact methods, making it difficult to meet the needs of clearing the wellbore under complex conditions.

[0003] Hydraulic jetting technology, as a highly efficient non-contact treatment method, can effectively compensate for the shortcomings of traditional mechanical treatment. However, current conventional hydraulic jetting equipment still has obvious shortcomings: the connection stability between coiled tubing and tubing string is not good; the existing clamping method of slip connectors has defects and is prone to insufficient clamping force; if excessive clamping is used to increase clamping force, it will cause damage to components, which will lead to a decrease in the contact tightness between the slip connector and the coiled tubing, further weakening the clamping effect of the slip connector on the coiled tubing. At the same time, the removal of debris in the well is not smooth, and there is a lack of scientific and standardized operating procedures, resulting in low operating efficiency and high equipment safety risks. Summary of the Invention

[0004] Therefore, it is necessary to provide a hydraulic jetting channel-opening device and method for treating damaged wells, addressing the problems of low efficiency and high safety risks associated with conventional hydraulic jetting equipment.

[0005] The above objectives are achieved through the following technical solutions: A hydraulic jetting device for treating casing-damaged wells includes a jetting head, coiled tubing, a tubing string mechanism, an injection head, and a surface pumping system. The jetting head is located at one end of the coiled tubing and is connected to it. The tubing string mechanism is located between the jetting head and the coiled tubing and serves to connect the jetting head and the coiled tubing. The injection head lowers the jetting head into the wellbore through the coiled tubing. The surface pumping system pumps the working medium into the wellbore through the coiled tubing and the jetting head. The tubing string mechanism includes a connector, which includes an upper tube, a lower tube, a clamp, and a top tube. The upper tube is sleeved outside the coiled tubing, and the lower tube is coaxial with the upper tube and threaded. The connection consists of a clamp sleeve fitted inside the lower tube and slidingly connected to the lower tube along its axial direction. Multiple spiral grooves penetrating the clamp sleeve wall are provided on the end face of the clamp sleeve, arranged circumferentially to give the clamp sleeve radial contraction capability. The projections of two adjacent grooves in the axial direction of the clamp sleeve overlap. A top sleeve is fitted inside the upper tube and abuts against the upper tube in its axial direction. The inner wall of the top sleeve is conical. The top sleeve is fitted outside the clamp sleeve and can push the grooved end of the clamp sleeve to contract radially through the conical surface. A continuous tubing is fitted inside the clamp sleeve and engages with the clamp sleeve during radial contraction.

[0006] Preferably, the nozzle has multiple oblique channels, which are inclined relative to the axial direction of the nozzle and have a uniform swirl direction, so that the ejected working medium forms a rotating jet.

[0007] Preferably, the nozzle has an internal spray plate with multiple through holes. Each oblique flow channel is connected to one of the through holes, and the extension direction of each through hole is consistent with the extension direction of the corresponding oblique flow channel.

[0008] Preferably, the clamping section between two adjacent through slots is a tile, each tile has a protrusion on its outer wall, and the inner wall of the top cylinder has multiple sliding grooves. Each protrusion is slidably disposed in a sliding groove. The sliding groove is spiral around the axis of the top cylinder. The direction of rotation of the sliding groove is the same as that of the through slot, and the pitch of the sliding groove is greater than that of the through slot. The direction of rotation of the jet ejected from the inclined channel is opposite to that of the sliding groove.

[0009] Preferably, each slip has multiple teeth arranged along the axial direction of the clamp on the side closest to the coiled tubing. The teeth are serrated and extend in an arc shape along the circumferential direction of the clamp. The teeth are pointed at both ends of the clamp and on the side furthest from the slip in the circumferential direction. The slip clamps the coiled tubing through the teeth.

[0010] Preferably, the tubing assembly further includes a safety joint, multiple stabilizers, and tubing stubs in the same number as the stabilizers. The safety joint is threaded to the lower tubing. The multiple stabilizers and multiple tubing stubs are located between the safety joint and the injection head and are arranged alternately in sequence. Adjacent stabilizers and tubing stubs are connected. The safety joint is connected to the stabilizer located at the end. The injection head is threaded to the tubing stub located at the end.

[0011] Preferably, a locking element is provided between any two structures in the threaded connection, the locking element being used to prevent relative rotation between the two threaded connection structures.

[0012] This invention also provides a method for creating channels using hydraulic jetting to treat casing-damaged wells, utilizing the aforementioned hydraulic jetting channel-creating equipment for treating casing-damaged wells, comprising the following steps: S1, the injection head and tubing string mechanism are installed sequentially at the bottom end of the coiled tubing to form a tubing string; S2, Top Probing and Initial Injection: Start the injection head, slowly lower the tubing string into the wellbore and pump the working medium in through the surface pumping system; S3, Progressive Penetration: During continuous injection, the continuous tubing is slowly lowered in a "jet-propulsion-short cycle" pattern, allowing the working medium jet to gradually penetrate or clear blockages at the break point. S4, Clean the well shaft and pipe string; S5, Return fluid monitoring and parameter optimization: Detect the flow rate, properties and debris composition of the return fluid in the wellbore to determine the condition inside the wellbore; After completing the spraying operation, S6, the pipe string was removed and transferred to the overhaul team to continue the channel construction.

[0013] Preferably, in step S2, the added working medium is a base liquid; in step S3, the working medium is a base liquid with added abrasive; and in step S4, the working medium is a base liquid without added abrasive.

[0014] Preferably, the abrasive is quartz sand of 40-70 mesh, the base liquid is composed of 0.5% drag reducer + guar gum, the viscosity is 30 mPa.s, and the sand ratio is 5%-7%.

[0015] The beneficial effects of this invention are as follows: by tightening the upper and lower tubes, the distance between the clamp and the top tube becomes smaller and smaller until the clamp is fitted inside the top tube and contacts the top tube. The top tube applies a radial force to the clamp towards its own axis through its conical surface, thereby clamping the coiled tubing. The clamp groove design ensures that when the clamp contracts radially, the clamping force on the coiled tubing is continuously distributed along the circumference of the coiled tubing. Compared with the traditional straight groove, the spiral groove structure avoids the interruption of clamping force, making the clamping force on the circumference of the coiled tubing more uniform, and effectively preventing the coiled tubing from being flattened, deformed or damaged due to local stress concentration. Attached Figure Description

[0016] Figure 1 A partial front view of a hydraulic jet channel-opening device for treating casing-damaged wells provided in an embodiment of the present invention; Figure 2This is a schematic diagram of the upper and lower pipe connections of a hydraulic jet channeling device for treating casing-damaged wells, provided in an embodiment of the present invention. Figure 3 for Figure 2 Sectional view along the middle AA direction; Figure 4 for Figure 3 Enlarged view of point B in the middle; Figure 5 This is a schematic diagram of the clamping structure of a hydraulic jet channeling device for treating casing damage wells, provided in an embodiment of the present invention. Figure 6 for Figure 5 Enlarged view of point C in the middle; Figure 7 A cross-sectional view of the top cylinder of a hydraulic jet channeling device for treating casing damage wells provided in an embodiment of the present invention; Figure 8 This is a schematic diagram of the jet head of a hydraulic jetting channel-opening device for treating casing-damaged wells, provided in an embodiment of the present invention. Figure 9 This is a cross-sectional view of the jet head of a hydraulic jetting channel-opening device for treating casing-damaged wells, provided in an embodiment of the present invention. Figure 10 This is a schematic diagram of the jetting disc of a hydraulic jetting channel-opening device for treating casing damage wells, provided in an embodiment of the present invention.

[0017] in: 100. Coiled tubing; 101. Upper tubing; 102. Lower tubing; 103. Clamp; 104. Top tube; 105. Through groove; 106. Sleeve; 107. Connecting tube; 108. Safety joint; 109. Centralizer; 110. Tubing sub; 201. Straight flow path; 202. Angled flow path; 203. Injection disc; 204. Through hole; 205. Pebble; 206. Protrusion; 207. Slide groove; 208. Teeth. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below through embodiments and in conjunction with the accompanying drawings. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0019] The component designations used in this document, such as "first" and "second," are merely for distinguishing the described objects and do not have any sequential or technical meaning. The terms "connection" and "linkage" used in this invention, unless otherwise specified, include both direct and indirect connections (linkages). It should be understood that the terms "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are used only for the convenience of describing the invention and simplifying the description. They 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, and therefore should not be construed as limiting the invention.

[0020] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0021] like Figures 1 to 10 As shown, this embodiment of the invention provides a hydraulic jetting channel-opening device for treating casing-damaged wells, including a jetting head, coiled tubing 100, a tubing string mechanism, an injection head, and a surface pumping system. The jetting head is located at one end of the coiled tubing 100 and communicates with it. The tubing string mechanism is located between the jetting head and the coiled tubing 100 and serves to connect the jetting head and the coiled tubing 100. The injection head lowers the jetting head into the wellbore through the coiled tubing 100. The surface pumping system pumps the working medium into the wellbore through the coiled tubing 100 and the jetting head. The tubing string mechanism includes a connector, which includes an upper... The tubing consists of a pipe 101, a lower pipe 102, a clamp 103, and a top cylinder 104. The upper pipe 101 is fitted outside the continuous tubing 100. The lower pipe 102 is coaxial with the upper pipe 101 and threadedly connected. The clamp 103 is fitted inside the lower pipe 102 and is slidably connected to the lower pipe 102 along the axial direction of the lower pipe 102. Multiple spiral through-grooves 105 are provided on the end face of the clamp 103, penetrating the wall of the clamp 103. The multiple through-grooves 105 are arranged circumferentially along the clamp 103, giving the clamp 103 radial contraction capability. The projections of two adjacent through-grooves 105 in the axial direction of the clamp 103 overlap.

[0022] The top cylinder 104 is sleeved inside the upper tube 101 and abuts against the upper tube 101 in its axial direction. The inner wall of the top cylinder 104 is a conical surface. The top cylinder 104 is sleeved outside the clamping cylinder 103 and can push the end of the clamping cylinder 103 with the through groove 105 to retract radially through the conical surface. The continuous oil tube 100 is sleeved inside the clamping cylinder 103 and the top cylinder 104, and is clamped and fixed to the clamping cylinder 103 when the clamping cylinder 103 retracts radially.

[0023] As the upper tube 101 and lower tube 102 are tightened, the distance between the clamp 103 and the top tube 104 becomes smaller and smaller until the clamp 103 is fitted inside the top tube 104 and contacts the top tube 104. The top tube 104 applies a radial force to the clamp 103 towards its own axis through its conical surface, thereby clamping the coiled tubing 100. The groove 105 of the clamp 103 ensures that when the clamp 103 contracts radially, the clamping force of its inner wall on the coiled tubing 100 is continuously distributed along the circumference of the coiled tubing 100. Compared with the traditional straight groove, the spiral groove structure avoids the interruption of clamping force, making the clamping force on the circumference of the coiled tubing 100 more uniform, effectively preventing the coiled tubing 100 from being flattened, deformed or damaged due to local stress concentration.

[0024] In this embodiment, the nozzle has a direct current channel 201 and multiple oblique flow channels 202. The oblique flow channels 202 are inclined relative to the axial direction of the nozzle, and the multiple oblique flow channels 202 have a uniform rotation direction so that the ejected working medium forms a rotating jet.

[0025] Specifically, the nozzle is cylindrical and coaxial with the downpipe 102, with the direct current channel 201 located in the center of the nozzle. Multiple oblique flow channels 202 are divided into groups, each group containing multiple oblique flow channels 202 arranged circumferentially along the nozzle, and sequentially arranged radially along the nozzle. When the nozzle injects the working medium, the medium is guided by the oblique flow channels 202 within the direct current channel 201 and ejected in a predetermined direction. The working medium ejected from the multiple oblique flow channels 202 is ejected in the same swirling direction. Upon entering the wellbore, the working medium rotates, effectively agitating the debris and gravel impacted by the jet within the wellbore. These debris and gravel are then efficiently carried to the surface by the return fluid, significantly reducing sand bed accumulation within the wellbore and facilitating the continuous drilling operation.

[0026] In this embodiment, the spray head is provided with a spray disk 203, and the spray disk 203 is provided with a plurality of through holes 204. The direct flow channel 201 and each oblique flow channel 202 are respectively connected to a through hole 204, and the extension direction of each through hole 204 is consistent with the extension direction of the corresponding direct flow channel 201 or oblique flow channel 202.

[0027] Specifically, the injection head includes a sleeve 106 and a connecting sleeve 107. The sleeve 106 has a bottom but no top. A straight flow channel 201 and an oblique flow channel 202 are disposed on the bottom of the sleeve 106 and penetrate the sleeve 106 along its axial direction. The injection disc 203 is disposed inside the sleeve 106 and abuts against the bottom of the sleeve 106. The connecting sleeve 107 is sleeved inside the sleeve 106 and threadedly connected to the sleeve 106. The connecting sleeve 107 abuts against the injection disc 203 to fix the injection disc 203. The extension direction of each through hole 204 on the injection disc 203 and the straight flow channel 201 or oblique flow channel 202 connected to it is consistent. When the working medium enters the straight flow channel 201 and oblique flow channel 202 from the through hole 204, its flow direction transitions smoothly, avoiding eddies and impacts caused by sudden changes in direction. This reduces the erosion and wear of the working medium on the inner walls of the direct flow channel 201 and the oblique flow channel 202, and extends the service life of the sleeve 106.

[0028] In this embodiment, the clamping cylinder 103 portion between two adjacent through slots 105 is shaped as a tile 205. Each tile 205 has a protrusion 206 on its outer wall. The inner wall of the top cylinder 104 has multiple sliding grooves 207. Each protrusion 206 is slidably disposed in a sliding groove 207. The sliding groove 207 is spiral about the axis of the top cylinder 104. The direction of rotation of the sliding groove 207 is the same as the direction of rotation of the through slot 105, and the pitch of the sliding groove 207 is greater than the pitch of the through slot 105. The direction of rotation of the jet ejected from the inclined channel 202 is opposite to the direction of rotation of the sliding groove 207.

[0029] Specifically, when the clamped coiled tubing 100 is subjected to an axial tension away from the injection head, the coiled tubing 100 will drive the clamp 103 to move closer to the top cylinder 104, and the sliding of the protrusion 206 in the groove 207 will increase the helix angle of the flap 205, shorten the axial length of the clamp 103, and at the same time, the area of ​​each flap 205 distributed in the circumferential direction of the coiled tubing 100 will increase, and the clamping force of the clamp 103 on the coiled tubing 100 will increase.

[0030] When the nozzle sprays the working medium, the nozzle is subjected to a reverse rotational force opposite to the jet direction. This reverse rotational force causes the nozzle to tend to drive the clamp 103 and the top cylinder 104 to rotate. With the cooperation of the protrusion 206 and the slide groove 207, the inclination angle of the flap 205 increases, and the area of ​​the coiled tubing 100 circumferentially covered and the clamping force in the radial direction increase, thereby ensuring the stability of the coiled tubing 100.

[0031] In this embodiment, each flap 205 has multiple teeth 208 arranged along the axial direction of the clamp 103 on the side near the coiled tubing 100. The teeth 208 are serrated, meaning that when the teeth 208 are cut along the axial direction of the clamp 103, their cross-section is triangular. This triangular structure significantly reduces the contact area between the teeth 208 and the coiled tubing 100. According to the pressure principle, under the same clamping force, the smaller the contact area, the greater the pressure per unit area, thus enabling the teeth 208 to firmly grip the surface of the coiled tubing 100, greatly improving the clamping capacity of the teeth 208. The teeth 208 extend in an arc shape along the circumferential direction of the clamp 103, and their curvature matches the outer diameter of the coiled tubing 100. The teeth 208 are pointed at both ends of the clamp 103 in the circumferential direction, away from the side of the flap 205, and the flap 205 clamps the coiled tubing 100 through the teeth 208.

[0032] Specifically, when the slip plate 205 changes its pitch under the action of the groove 207, the line connecting the two ends of the slip teeth 208 is no longer perpendicular to the axis of the coiled tubing 100. The sharp corners at both ends of the slip teeth 208 are more likely to "pierce" into the surface of the coiled tubing 100, forming an effective mechanical block against the axial movement of the coiled tubing 100, further enhancing the anti-slippage ability of the slip teeth 208. If the coiled tubing 100 is subjected to axial tension at this time, the embedded sharp corners generate a self-locking effect. The greater the tension, the stronger the locking effect, effectively preventing slippage.

[0033] Each tile 205 has an inclined surface that matches the conical surface of the top cylinder 104, which increases the contact area between the tile 205 and the top cylinder 104, making the force more uniform when the tile 205 deforms.

[0034] In this embodiment, the tubing column mechanism further includes a safety joint 108, a plurality of centralizers 109, and tubing stubs 110 in the same number as the centralizers 109. The safety joint 108 is threadedly connected to the lower tube 102. The plurality of centralizers 109 and the plurality of tubing stubs 110 are located between the safety joint 108 and the injection head and are arranged alternately in sequence. Adjacent centralizers 109 and tubing stubs 110 are connected. The safety joint 108 is connected to the centralizer 109 located at the end. The connecting sleeve 107 of the injection head is threadedly connected to the tubing stub 110 located at the end.

[0035] Specifically, multiple stabilizers 109 are installed to provide support inside the wellbore, while the orientation of the end of the coiled tubing 100 is adjusted to prevent the coiled tubing 100 from exerting lateral force on the injection head, thus increasing the friction between the injection head and the wellbore and facilitating precise repair of the wellbore by the working medium at the location to be repaired.

[0036] In this embodiment, a locking element is provided between any two threaded structures to prevent relative rotation between the two threaded structures.

[0037] Specifically, the upper tube 101 is sleeved on the lower tube 102. A first bolt is provided between the upper tube 101 and the lower tube 102. The first bolt passes through the upper tube 101 in the radial direction and is threadedly connected to the upper tube 101. A first groove is provided on the lower tube 102. After the upper tube 101 and the lower tube 102 are stably connected, the first bolt can be inserted into the first groove to restrict the relative rotation of the upper tube 101 and the lower tube 102, thus ensuring the connection stability of the upper tube 101 and the lower tube 102. The connecting sleeve 107 is sleeved on the oil pipe stub 110 located at the end. A second bolt is provided between the connecting sleeve 107 and the oil pipe stub 110 connected thereto. The second bolt passes through the connecting sleeve 107 in the radial direction and is threadedly connected to the connecting sleeve 107. A second groove is provided on the oil pipe stub 110 that is threadedly connected to the connecting sleeve 107. After the threaded connection between the connecting sleeve 107 and the oil pipe stub 110 is stable, the second bolt can be inserted into the second groove after being threadedly connected to the connecting sleeve 107, thereby restricting the relative rotation of the connecting sleeve 107 and the oil pipe stub 110.

[0038] The end of the lower tube 102 away from the upper tube 101 is inserted into the safety joint 108 and threadedly connected to the safety joint 108. A third bolt is provided between the safety joint 108 and the lower tube 102. The third bolt passes through the safety joint 108 in the radial direction of the upper tube 101 and is threadedly connected to the safety joint 108. A third groove is provided on the lower tube 102. After the safety joint 108 and the lower tube 102 are threadedly connected, the third bolt can be inserted into the third groove and restrict the relative rotation of the safety joint 108 and the lower tube 102.

[0039] A fourth bolt is provided between the upper tube 101 and the top cylinder 104. The fourth bolt passes through the upper tube 101 in the radial direction and is threadedly connected to the upper tube 101. After the top cylinder 104 is sleeved inside the upper tube 101, the fourth bolt is installed and abuts against the top cylinder 104 to limit the top cylinder 104 and prevent relative rotation between the top cylinder 104 and the upper tube 101.

[0040] A fifth bolt is provided between the sleeve 106 and the connecting cylinder 107. The fifth bolt is threadedly connected to the sleeve 106. A fourth groove is provided on the connecting cylinder 107. After the fifth bolt is connected to the sleeve 106, it can be inserted into the fourth groove to restrict the relative rotation of the sleeve 106 and the connecting cylinder 107.

[0041] The hydraulic jetting equipment for treating casing-damaged wells also includes existing ground-based supporting devices, such as an instrument vehicle, for recording data such as pressure, displacement, and fluid inflow.

[0042] The working principle of the hydraulic jet channel-opening device for treating casing-damaged wells provided in the above embodiments is as follows: First, connect the connecting sleeve 107 and the tubing section 110 and fix them with the second bolt. Then, install the lower tube 102 onto the safety connector 108 and fix it to the lower tube 102 with the third bolt. Next, insert the continuous tubing 100 into the upper tube 101, the top sleeve 104, the clamp 103 and the lower tube 102 in sequence. Then connect the upper tube 101 and the lower tube 102. During the relative rotation of the upper tube 101 and the lower tube 102, the clamp 103 is stationary in its circumferential direction relative to the lower tube 102. The top sleeve 104 squeezes the flaps 205 of the clamp 103 through its conical surface, causing multiple flaps 205 to converge towards the center and clamp the continuous tubing 100. At the same time, the protrusions 206 on the flaps 205 drive the top sleeve 104 to rotate relative to the upper tube 101 through the sliding groove 207. When the upper tube 101 and the lower tube 102 are connected in place, the protrusion 206 is still in the middle area of ​​the slide groove 207 and can slide back and forth in the slide groove 207. Then, the upper tube 101 and the lower tube 102 are fixed with the first bolt, and the top cylinder 104 and the upper tube 101 are fixed with the fourth bolt.

[0043] The injection head is then placed inside the wellbore and the coiled tubing 100 is delivered through the injection head, allowing the injection head to reciprocate within the wellbore. As the injection head advances, the coiled tubing 100 applies a thrust to the lower tubing 102, maintaining a relatively stable connection. When the coiled tubing 100 drives the upper tubing 101 and lower tubing 102 back, it applies a pulling force to the lower tubing 102. At this time, under the action of the clamp 103, the coiled tubing 100 tends to move the clamp 103 closer to the top tube 104; and under the action of the conical surface of the top tube 104, the flaps 205 on the clamp 103 tend to move closer together, thus clamping the coiled tubing 100 more tightly.

[0044] Meanwhile, with the cooperation of the protrusion 206 and the groove 207, the pitch of the tile 205 also tends to decrease, and the circumferential coverage area of ​​the continuous tubing 100 will also increase, improving the clamping stability of the clamp 103.

[0045] If working medium is introduced into the continuous tubing 100, the working medium will form a jet after passing through the injection disc 203 and the sleeve 106. The jet is rotating and impacts the blocked position in the wellbore. The jet will generate a reverse rotational force on the sleeve 106 and the connecting sleeve 107. This force is transmitted to the downpipe 102 through the tubing sub 110 and the centralizer 109. The downpipe 102 drives the clamp 103 to rotate.

[0046] This trend causes the end of the flap 205 with the protrusion 206 to further converge radially under rotation. Since the flap 205 is far from the protrusion 206 and is far from the top cylinder 104, its deformation capacity is weaker, so the clamping force on the continuous tubing 100 is relatively small, and therefore it is easier to rotate synchronously with the lower tube 102.

[0047] Under the action of the groove 207, the end of the flap 205 with the protrusion 206 tends to converge, enhancing its clamping force on the coiled tubing 100. When the coiled tubing 100 pushes the injection head forward, the clamping force of the clamp 103 on the coiled tubing 100 is relatively reduced, and the reverse force of the jet allows the clamp 103 to better clamp the coiled tubing 100.

[0048] This invention also provides a method for creating channels using hydraulic jetting to treat casing-damaged wells, utilizing the aforementioned hydraulic jetting channel-creating equipment for treating casing-damaged wells, comprising the following steps: S1, the injection head and tubing string mechanism are installed sequentially at the bottom end of the coiled tubing 100 to form a tubing string; at this time, the coiled tubing 100 is inserted into the upper tube 101, the top cylinder 104 and the clamp 103. The upper tube 101 is threadedly connected to the lower tube 102 and locked by the first bolt. The clamp 103 clamps the coiled tubing 100 by the flaps 205.

[0049] S2, Top Probing and Initial Injection: Start the injection head, slowly lower the tubing string into the wellbore, and pump the base fluid through the surface pumping system. The base fluid consists of 0.5% drag reducer + guar gum, with a viscosity of 30 mPa·s. Set the injection pressure to 60 MPa and the flow rate to 2 m³ / min. Slowly lower the coiled tubing 100 at a low flow rate until the injection head contacts the top of the fallen object or the fracture area. After confirming contact through drilling pressure data or pump pressure changes on the instrument vehicle, raise the tool to a preset distance of 0.1 m to 0.2 m, increase the flow rate to the working flow rate, and begin injecting abrasive to form an abrasive jet for initial fracturing of the fracture location.

[0050] S3, Progressive Penetration: During continuous jetting, the coiled tubing 100 is slowly lowered in a "jet-propulsion-short circulation" cycle. This allows the abrasive-added base fluid jet to gradually penetrate or clear blockages at the fracture surface. The abrasive used is 40-70 mesh quartz sand, with a sand ratio of 5%-7%. Short circulation ensures that the blockage at the current layer is fully broken up, while the abrasive-added base fluid jet sprays the sidewalls of the formed channel to clear residual protrusions, enlarge and smooth the channel, and ensure the passability of the tubing string at the jetting position. During this process, the coiled tubing 100 is lowered at a rate of 0.2 m per minute, with a pause of 10-15 minutes every 0.1 m to ensure that the debris at that point is fully broken up. This cycle continues until the jet penetrates the entire fracture surface and the debris blockage, forming a preliminary channel.

[0051] By controlling the residence time of the jet at each location, effective fragmentation of hard materials is ensured, preventing energy dispersion and efficiency reduction due to excessively rapid propulsion, thus achieving controllable and stable penetration. Short cycles refine and expand the initially cleared channel, ensuring a uniform and smooth inner diameter and avoiding the formation of irregular channels such as "keyholes," laying a good foundation for subsequent operations and avoiding secondary work.

[0052] S4. Clean the wellbore and tubing string. After penetrating the fracture to a depth of 0.5m to 1m, stop adding abrasive and continue pumping base fluid for 90 minutes to flush the wellbore. The base fluid circulates and cleans the area near the fracture where a channel has formed, removing residual debris from the wellbore. Frequently raise and lower the tubing string to prevent sticking. Once the 100mm coiled tubing string is raised and lowered past the fracture without significant clamping force, the channel is considered clear.

[0053] S5, Return Fluid Monitoring and Parameter Optimization: Monitor the flow rate, properties, and debris composition of the return fluid within the wellbore to assess the wellbore conditions. Throughout the operation, monitor the flow rate, properties, and debris composition of the return fluid at the wellhead in real time, and dynamically adjust parameters such as pump injection rate and abrasive ratio accordingly to optimize crushing efficiency and prevent stuck pipe. Specifically, if monitoring reveals a decrease in large metal debris in the return fluid, appropriately reduce the abrasive concentration to 5% to maintain efficient cutting and conserve materials.

[0054] Using the returned material as real-time feedback on the downhole crushing effect allows the operating parameters to be adaptively adjusted according to the actual working conditions, maintaining a consistently efficient crushing state, avoiding rigid jamming of tools and falling materials, reducing the probability of stuck drill bit, and providing early warning of potential downhole risks.

[0055] S6. After completing the spraying operation, the tool string is then lifted and lowered to verify the passage. Once the passage is confirmed to be unobstructed, the pipe string is pulled out and transferred to the overhaul team to continue drilling the passage with the drill bit tip.

[0056] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0057] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the appended claims.

Claims

1. A hydraulic jetting channel-opening device for treating casing-damaged wells, characterized in that, include: The system comprises an injection head, coiled tubing, tubing string mechanism, injection head, and surface pumping system. The injection head is located at one end of the coiled tubing and is connected to it. The tubing string mechanism is located between the injection head and the coiled tubing and serves to connect them. The injection head lowers the injection head into the wellbore through the coiled tubing. The surface pumping system pumps the working medium into the wellbore through the coiled tubing and the injection head. The tubing string mechanism includes a connector, which comprises an upper tube, a lower tube, a clamp, and a top tube. The upper tube is fitted over the coiled tubing, and the lower tube is coaxial with and threaded to the upper tube. The clamp is fitted over the lower tube. The inner tube is slidably connected to the lower tube along the axial direction. Multiple spiral grooves penetrating the tube wall are opened on the end face of the clamp. The multiple grooves are arranged along the circumference of the clamp, giving the clamp radial contraction capability. The projections of two adjacent grooves in the axial direction of the clamp overlap. The top tube is sleeved inside the upper tube and abuts against the upper tube in its axial direction. The inner wall of the top tube is conical. The top tube is sleeved outside the clamp and can push the end of the clamp with grooves to contract radially through the conical surface. The continuous tubing is sleeved inside the clamp and is clamped and fixed to the clamp when the clamp contracts radially.

2. The hydraulic jetting channel-opening device for treating casing-damaged wells according to claim 1, characterized in that, The nozzle has multiple oblique channels, which are inclined relative to the axis of the nozzle and have a uniform swirl direction, so that the ejected working medium forms a rotating jet.

3. The hydraulic jetting channel-opening device for treating casing-damaged wells according to claim 2, characterized in that, The nozzle has an internal spray plate with multiple through holes. Each oblique flow channel is connected to one of the through holes, and the extension direction of each through hole is consistent with the extension direction of the corresponding oblique flow channel.

4. The hydraulic jetting channel-opening device for treating casing-damaged wells according to claim 2, characterized in that, The clamping section between two adjacent through slots is shaped like a tile. Each tile has a protrusion on its outer wall, and the inner wall of the top cylinder has multiple sliding grooves. Each protrusion is slidably set in a sliding groove. The sliding groove is spiral around the axis of the top cylinder. The direction of rotation of the sliding groove is the same as that of the through slot, and the pitch of the sliding groove is greater than that of the through slot. The direction of rotation of the jet ejected from the inclined channel is opposite to that of the sliding groove.

5. The hydraulic jetting channel-opening device for treating casing-damaged wells according to claim 1, characterized in that, Each slip has multiple teeth arranged along the axial direction of the clamp on the side closest to the coiled tubing. The teeth are serrated and extend in an arc shape along the circumferential direction of the clamp. The teeth are pointed at both ends of the clamp and on the side furthest from the slip. The slip clamps hold the coiled tubing through the teeth.

6. The hydraulic jetting channel-opening device for treating casing-damaged wells according to claim 1, characterized in that, The tubing system also includes a safety joint, multiple stabilizers and tubing stubs of the same number as the stabilizers. The safety joint is threaded to the lower tubing. The multiple stabilizers and multiple tubing stubs are located between the safety joint and the injection head and are arranged alternately in sequence. Adjacent stabilizers and tubing stubs are connected. The safety joint is connected to the stabilizer located at the end. The injection head is threaded to the tubing stub located at the end.

7. A hydraulic jetting channel-opening device for treating casing-damaged wells according to claim 6, characterized in that, A locking element is provided between any two structures in a threaded connection to prevent relative rotation between the two threaded connections.

8. A method for treating casing-damaged wells using hydraulic jetting to create channels, comprising a hydraulic jetting device for treating casing-damaged wells as described in any one of claims 1 to 7, characterized in that, Includes the following steps: S1, the injection head and tubing string mechanism are installed sequentially at the bottom end of the coiled tubing to form a tubing string; S2, Top Probing and Initial Injection: Start the injection head, slowly lower the tubing string into the wellbore and pump the working medium in through the surface pumping system; S3, Progressive Penetration: During continuous injection, the continuous tubing is slowly lowered in a "jet-propulsion-short cycle" pattern, allowing the working medium jet to gradually penetrate or clear blockages at the break point. S4, Clean the well shaft and pipe string; S5, Return fluid monitoring and parameter optimization: Detect the flow rate, properties and debris composition of the return fluid in the wellbore to determine the condition inside the wellbore; After completing the spraying operation, S6, the pipe string was removed and transferred to the overhaul team to continue the channel construction.

9. A method for treating casing-damaged wells using hydraulic jetting to create channels, as described in claim 8, is characterized in that... In step S2, the added working medium is a base liquid; in step S3, the working medium is a base liquid with added abrasive; in step S4, the working medium is a base liquid without added abrasive.

10. The method for treating casing-damaged wells using hydraulic jetting to create channels according to claim 9, characterized in that, The abrasive is quartz sand of 40-70 mesh. The base liquid consists of 0.5% drag reducer and guar gum, with a viscosity of 30 mPa.s. The sand ratio is 5%-7%.

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