Jet flow cutting acidification tool for coiled tubing and acidification system

Abstract

The utility model discloses a jet cutting acidification tool and acidification system for coiled tubing, and relates to the technical field of oil-gas exploration and development. The jet flow cutting acidification tool for the coiled tubing comprises a mandrel, a spray head and a speed reduction assembly, and the interior of the mandrel is hollow to form a jet flow channel; the spray head is arranged at the first end of the mandrel and communicated with the jet flow channel, two first nozzles are oppositely arranged on the spray head in the radial direction of the spray head, and the first nozzles can discharge liquid in the axial direction of the spray head, so that the mandrel rotates in the axial direction of the spray head along with liquid discharged by the first nozzles; at least one second nozzle is arranged at one end, deviating from the core shaft, of the spray head; the speed reduction assembly is arranged outside the mandrel in the axial direction of the mandrel, and the speed reduction assembly can respond to the increase of the rotating speed of the mandrel so as to deform and increase the friction force between the speed reduction assembly and the mandrel.

Description

Technical Field

[0001] This application relates to the field of oil and gas exploration and development technology, and in particular to a jet cutting acidizing tool and acidizing system for coiled tubing. Background Technology

[0002] The main acidizing process currently is coiled tubing-driven acidizing, which uses a continuous dragging method to achieve uniform distribution of acid in horizontal wells.

[0003] However, the high friction and low flow rate of coiled tubing make it difficult for acid to penetrate low-permeability layers, affecting the acidizing effect. At the same time, under the condition of uniform acid distribution, the acid absorption of high-permeability formations is much higher than that of low-permeability formations, resulting in uneven production after acidizing and low utilization of effective production layers. Utility Model Content

[0004] This application provides a jet cutting acidizing tool for coiled tubing, comprising:

[0005] A mandrel, the interior of which is hollow to form a jet channel;

[0006] The nozzle is disposed at the first end of the mandrel and connected to the jet channel. Two first nozzles are disposed opposite each other in the radial direction of the nozzle. The first nozzles are capable of discharging liquid around the axial direction of the nozzle, so that the mandrel rotates around its axial direction with the liquid discharge from the first nozzles. At least one second nozzle is disposed at the end of the nozzle opposite to the mandrel.

[0007] A speed reduction assembly is disposed axially around the mandrel outside the mandrel, and the speed reduction assembly is capable of deforming to increase the frictional force between itself and the mandrel in response to an increase in the rotational speed of the mandrel.

[0008] In some modified embodiments of the first aspect of this application, the aforementioned jet cutting acidizing tool for coiled tubing further includes a reservoir cavity arranged axially around the mandrel;

[0009] The deceleration assembly is disposed in the liquid storage chamber. The deceleration assembly includes an expanding liquid and a contact element. The contact element is movably sleeved outside the mandrel. The expanding liquid fills the liquid storage chamber.

[0010] The expanding liquid has a target coefficient of thermal expansion.

[0011] In some modified embodiments of the first aspect of this application, the aforementioned jet cutting acidizing tool for coiled tubing further includes a movable component;

[0012] The movable component is movably sleeved on the outside of the mandrel adjacent to the liquid storage cavity, so as to be able to reciprocate along the axial direction of the mandrel;

[0013] The liquid storage chamber has an opening at least on one side facing the movable component, so that the expanding liquid, when heated, can expand and drive the movable component to move axially along the mandrel.

[0014] In some modified embodiments of the first aspect of this application, the aforementioned continuous tubing jet cutting acidizing tool, wherein the movable component includes a telescopic member and a balance piston;

[0015] The telescopic component and the balance piston are sequentially arranged between the nozzle and the deceleration assembly;

[0016] The deceleration assembly can drive the balance piston to move axially along the spindle, and the telescopic member can provide a force to reset the balance piston.

[0017] In some modified embodiments of the first aspect of this application, the aforementioned jet cutting acidizing tool for coiled tubing includes a first spacer and a second spacer that are sequentially fitted together.

[0018] The inner and outer walls of the first spacer are provided with receiving grooves, and the extending direction of the receiving grooves is the same as the liquid outlet direction of the first nozzle.

[0019] In some modified embodiments of the first aspect of this application, the aforementioned continuous tubing jet cutting acidizing tool further includes a connector disposed at the end of the mandrel opposite to the nozzle, the connector being used to connect to the supply tubing; the connector is provided with a connecting cylinder inside, the connecting cylinder being used to connect to the jet channel;

[0020] A second telescopic component is movably sleeved on the outside of the connecting cylinder, and the second telescopic component can affect the movement of the connecting cylinder toward the nozzle.

[0021] In some modified embodiments of the first aspect of this application, the aforementioned jet cutting acidizing tool for coiled tubing is provided with a pressure relief channel in the joint, one end of which is connected to the liquid storage chamber and the other end is connected to the outside of the jet cutting acidizing tool for coiled tubing.

[0022] It also includes the casing;

[0023] The housing is fitted over the mandrel, and the housing is fixedly connected to the connector.

[0024] In some modified embodiments of the first aspect of this application, the aforementioned jet cutting acidizing tool for coiled tubing is provided with an opening on the outer wall of the joint, the opening being connected to the pressure relief channel, and a screw being provided inside the opening.

[0025] In some modified embodiments of the first aspect of this application, the aforementioned jet cutting acidizing tool for coiled tubing is provided with a first bearing and a second bearing at both ends along the axial direction of the mandrel.

[0026] The sealing assembly is located on the side of the second bearing opposite to the liquid storage chamber, and the pressure relief channel is located on the side of the sealing assembly in the radial direction of the mandrel opposite to the mandrel;

[0027] The second bearing is located on the side of the liquid storage chamber opposite to the nozzle.

[0028] A second aspect of this application provides an acidizing system comprising at least one of the aforementioned jet cutting acidizing tools for coiled tubing.

[0029] Compared to existing technologies, the jet cutting acidizing tool for coiled tubing provided in this embodiment, by setting a jet channel within the mandrel and cooperating with an eccentric first nozzle, can simultaneously carry both the proppant-carrying fluid and the acid. This enables both rotating liquid ejection perforation and effective acid ejection. Furthermore, the eccentric first nozzle, the second nozzle at the end, and the deceleration assembly reduce rotational speed, facilitating the formation of a jet that cuts the production layer, improving perforation efficiency, and avoiding uneven acid penetration. This embodiment solves the problems of uneven production after acidification and low effective production layer utilization caused by existing acidizing operations. Attached Figure Description

[0030] The above and other objects, features, and advantages of exemplary embodiments of this application will become readily understood by reading the following detailed description with reference to the accompanying drawings. In the drawings, several embodiments of this application are illustrated by way of example and not limitation, with the same or corresponding reference numerals denoteing the same or corresponding parts, wherein:

[0031] Figure 1 A schematic diagram of the external structure of the jet cutting acidizing tool for coiled tubing provided in this embodiment is shown.

[0032] Figure 2 schematically shown Figure 1 A schematic diagram of the cross-section of the coaxial tubing acidizing tool along AA using a jet cutting tool;

[0033] Figure 3 The internal structure of the nozzle in the jet cutting acidizing tool for coiled tubing provided in this embodiment is schematically shown.

[0034] Figure 4 The schematic diagram illustrates the structural features of the components that mate with the mandrel in the jet cutting acidizing tool for coiled tubing provided in this embodiment.

[0035] Figure 5 The schematic diagram illustrates the structure of the first spacer in the jet cutting acidizing tool for coiled tubing provided in this embodiment.

[0036] Reference numerals: 1. Mandrel; 11. Jet channel; 12. Nozzle connector; 2. Nozzle; 21. First nozzle; 22. Second nozzle; 23. Nozzle inner cylinder; 24. Spiral opening; 25. End opening; 3. Deceleration assembly; 31. Contact element; 311. First spacer; 312. Second spacer; 313. Receiving groove; 4. Housing; 41. Liquid storage chamber; 42. First bearing; 43. Second bearing; 5. Connector; 51. Connecting cylinder; 52. Pressure relief channel; 53. Screw; 6. Movable assembly; 61. Telescopic component; 62. Balance piston; 63. Piston seat; 7. Second telescopic component; 71. Mounting ball seat; 72. Nut seat; 8. Sealing assembly; 81. Lip seal; 82. Sealing gasket ring. Detailed Implementation

[0037] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

[0038] It should be noted that, unless otherwise stated, the technical or scientific terms used in this application shall have the ordinary meaning as understood by one of ordinary skill in the art to which this application pertains.

[0039] The technical solution of this application embodiment is to solve the above-mentioned technical problems, and the general idea is as follows:

[0040] Example 1

[0041] Reference Appendix Figure 1 and attached Figure 2 The continuous tubing jet cutting acidizing tool provided in this application includes a mandrel 1, a nozzle 2, and a reduction assembly 3. The mandrel 1 is hollow to form a jet channel 11. The nozzle 2 is disposed at a first end of the mandrel 1 and communicates with the jet channel 11. Two first nozzles 21 are disposed opposite each other along the radial direction of the nozzle 2. The first nozzles 21 can discharge liquid around the axial direction of the nozzle 2, so that the mandrel 1 rotates around its axial direction with the liquid discharge from the first nozzles 21. At least one second nozzle 22 is disposed at the end of the nozzle 2 away from the mandrel 1. The reduction assembly 3 is disposed outside the mandrel 1 around the axial direction of the mandrel 1. The reduction assembly 3 can deform and increase the frictional force between itself and the mandrel 1 in response to the increase of the rotational speed of the mandrel 1.

[0042] Understandably, to address the issues of uneven product flow and low utilization of effective production layers resulting from existing acidizing operations, this embodiment provides a jet cutting acidizing tool for coiled tubing. This tool is detachably connected to the coiled tubing. The mandrel 1 contains a jet channel 11, capable of carrying and guiding both the sand-carrying fluid and the acid. The two eccentric first nozzles 21 on the nozzle 2 drive the mandrel 1 to rotate as they eject the liquid flow axially around it. The faster the mandrel 1 rotates, the faster the deceleration assembly 3 and the mandrel... The greater the friction between the two nozzles, the more the rotational speed of the mandrel 1 is limited, thus slowing it down. This ensures that the liquid ejected from the first nozzle 21 can form a jet to cut the production layer. When the jet channel 11 carries the sand-carrying liquid, it can perforate the production layer. Then, the liquid carried in the jet channel 11 is changed to acid, which is used in conjunction with the perforation for acidification. This improves the perforation and acidification effects in a one-time and targeted manner. Different degrees of perforation are performed on production layers with different permeability to ensure the uniformity of the acidification effect, greatly improving the utilization of the effective production layer. At the same time, in this embodiment, a second nozzle 22 is also provided at the end of the nozzle 2. The reaction force of the liquid ejected from the second nozzle 22 further reduces the rotational speed of the mandrel 1, preventing excessive rotational speed from generating water mist and improving the perforation effect. The reduced rotational speed can be, but is not limited to, 8 r / min, which is extremely helpful for the deep acidification and development of low-permeability reservoirs.

[0043] The coiled tubing jet cutting acidizing tool provided in this embodiment can be screwed into the coiled tubing connector, or connected via, but not limited to, the male and female fittings of the connector, thereby enabling the supply of proppant and acid. It is easy to understand that the coiled tubing jet cutting acidizing tool can be run downhole into the target area along with the coiled tubing, performing perforation and acidizing within that area. This process requires no tool switching; the entire operation of perforation, fracturing, and acidizing can be completed in one go, significantly reducing operational difficulty and improving acidizing efficiency. Specifically, the coiled tubing jet cutting acidizing tool first jets proppant-carrying fluid. The outflowing proppant-carrying fluid forms a jet that impacts the casing and rock, creating cavities. The pressure at the perforation orifice further increases until it exceeds the reservoir pressure, achieving deep penetration. The proppant-carrying fluid carries fracturing sand continuously into the formation, providing support for the fractures. When the subsequent acid is injected, it flows within the fractures, further promoting fracture extension and opening the production zone.

[0044] Among them, reference appendix Figure 2 and attached Figure 4The mandrel 1 is a rigid cylindrical structure, which may be, but is not limited to, made of stainless steel. Its hollow interior forms a jet channel 11, serving as a flow channel for carrying sand and acidizing fluid. The size of the mandrel 1 is not limited here and can be designed and adjusted according to the length requirements of the actual device. It is easy to understand that a housing 4 must be provided outside the mandrel 1. The housing 4 is fitted over the mandrel 1, and a connector 5 is fixed to the end of the housing 4 facing away from the nozzle 2 for detachable connection to the continuous tubing. The housing 4 is a rigid structure, serving as the overall outer shell of the continuous tubing jet cutting acidizing tool. It protects the internal structures such as the mandrel 1 and also forms the mounting carrier for the deceleration assembly 3. The housing 4 can be a one-piece cylindrical structure or a multi-section cylindrical structure connected together; this configuration is easily understood and implemented by those skilled in the art and will not be pursued further here. The connector 5 is a rigid connector structure, which may be, but is not limited to, a quick connector, threaded connector, compression fitting, flared connector, rotary connector, etc.

[0045] Among them, reference appendix Figure 1 and attached Figure 3 The nozzle 2 is a rigid structure, and its interior may have a flow channel or a receiving cavity to connect to the jet channel 11. The nozzle 2 is fixedly connected to the spindle 1, and there will be no relative movement between the two. The connection can be, but is not limited to, screw connection, pin locking, etc., as shown in the attached diagram. Figure 1 and attached Figure 2 In this embodiment, a nozzle connector 12 can be provided at the end of the mandrel 1. The nozzle connector 12 is fixed to the mandrel 1 by a pin, and the nozzle connector 12 is screwed to the nozzle 2. The shape and size of the nozzle 2 can be designed and adjusted according to actual needs. For example, it can be... Figure 1 One end shown has a smooth spherical surface, which improves its guiding effect during well entry. To increase the pressure of the ejected fluid, in this embodiment, a nozzle inner cylinder 23 can be provided inside the nozzle 2, such as... Figure 3As shown, the inner cylinder 23 of the nozzle has a spiral opening 24 on its wall. The spiral opening 24 is arranged one-to-one with the two first nozzles 21, which not only connects the inner cylinder 23 of the nozzle to the first nozzles 21, but also increases the liquid pressure of the nozzle 2 through the spiral opening 24. Correspondingly, the end of the inner cylinder 23 away from the spindle 1 also has an end opening 25 to correspond to the second nozzle 22. The above-mentioned configuration of the inner cylinder 23 of the nozzle can be easily understood and implemented by those skilled in the art, and will not be described in detail here. In this embodiment, the first nozzle 21 is an eccentric nozzle. Its liquid outlet or jet is not located on the central axis of the nozzle body, but is inclined relative to the central axis. As a result, when liquid or gas is discharged, a biasing torque is generated, which causes the nozzle to rotate or to generate a specific angle impact force on the target surface. In this embodiment, the first nozzle 21 is set to discharge liquid around the axial direction of the nozzle 2, and the impact force generated when discharging liquid can drive the nozzle 2 and the spindle 1 to rotate simultaneously. In this embodiment, the number of first nozzles 21 is set to two, which can achieve driving rotation without excessive acceleration. The second nozzle 22 can be either an eccentric or non-eccentric nozzle. The second nozzle 22 is positioned at the end of the nozzle 2 opposite to the spindle 1. The reaction force generated when liquid is discharged from the second nozzle 22 affects the rotation of the nozzle 2, thus slowing it down. The number of second nozzles 22 can be designed and adjusted according to actual needs; it can be one, two, or... Figure 1 The arrangement of the three or more second nozzles 22 shown can also be designed and adjusted according to actual needs, for example... Figure 1 The nozzles shown are arranged in a straight line along the radial direction of the nozzle 2, or they can be arranged around the axis of the nozzle 2, etc. In this embodiment, the liquid output of the second nozzle 22 can be the same as or different from that of the first nozzle 21, and can be designed and adjusted according to actual needs.

[0046] The deceleration component 3 is located outside the spindle 1 and does not rotate with the spindle 1. It can be sandwiched between the housing 4 and the spindle 1, or it can be fixedly installed on the inner wall of the housing 4. As the rotational speed of the spindle 1 increases, it deforms to increase the frictional force between itself and the spindle 1, thereby limiting the rotational speed of the spindle 1 and decelerating its rotation. The deceleration component 3 can be related to the rotational speed of the spindle 1 or to the temperature generated by friction during the rotation of the spindle 1. For example, a related sensor can be set up in conjunction with the clamping device. When an increase in the rotational speed of the spindle 1 is detected, the clamping effect is increased. Another example is that a fluid with a high coefficient of thermal expansion can be used in conjunction with the clamping device. The higher the rotational speed of the spindle 1, the greater the expansion of the fluid, which drives the alarm device to increase the clamping effect. The deceleration component 3 can be arranged around the axial direction of the spindle 1 for a full circle, or it can be arranged in a partial area. It can be designed and adjusted according to actual needs. Correspondingly, the size of the deceleration component 3 in the axial direction of the spindle 1 can also be designed and adjusted according to actual needs. The larger the size, the more obvious the deceleration effect. For example, when the radial dimension of the jet channel 11 and the jet flow rate of the first nozzle 21 are large, the size of the deceleration component 3 in the axial direction of the spindle 1 can be set to be larger to improve its deceleration effect.

[0047] As described above, the continuous tubing jet cutting acidizing tool provided in this embodiment, by setting a jet channel 11 within the mandrel 1 in conjunction with an eccentric first nozzle 21, can simultaneously carry both the sand-carrying fluid and the acid. This enables both the rotating liquid-ejecting perforation of the device and the effective ejection of the acid. Furthermore, the eccentric first nozzle 21, the end second nozzle 22, and the deceleration assembly 3 achieve rotational deceleration, facilitating the formation of a jet of ejected liquid to cut the production layer, improving perforation efficiency, and avoiding the problem of uneven acid penetration. This embodiment solves the problem of uneven production after acidizing and low effective production layer utilization caused by existing acidizing operations.

[0048] In this article, the term "and / or" is merely a description of the relationship between related objects, indicating that there can be three relationships, such as A and / or B. Specifically, it can be understood as: A and B can be included at the same time, A can exist alone, or B can exist alone, and any of the above three situations can be met.

[0049] Further, see Appendix Figure 2 The jet cutting acidizing tool for continuous tubing provided in this embodiment further includes a liquid storage chamber 41, which is arranged axially around the mandrel 1. The deceleration assembly 3 is disposed inside the liquid storage chamber 41. The deceleration assembly 3 includes an expanding liquid and a contact member 31. The contact member 31 is movably sleeved outside the mandrel 1. The expanding liquid fills the liquid storage chamber 41. The expanding liquid has a target coefficient of thermal expansion.

[0050] Understandably, in order to achieve the deceleration effect of the deceleration component 3 rotating with the spindle 1, a liquid storage cavity 41 is provided inside the housing 4 for the spindle 1. The liquid storage cavity 41 is filled with an expanding liquid having a target thermal expansion coefficient and a contact element 31. During the rotation of the spindle 1, heat is generated, causing the expanding liquid to expand and compress the contact element 31, increasing the friction between it and the spindle 1, thereby achieving the deceleration effect. Correspondingly, the liquid storage cavity 41 can be formed by arranging two first bearings 42 and a second bearing 43 at intervals along the axial direction of the spindle 1 inside the housing 4. These bearings can be, but are not limited to, ball bearings. This arrangement can both form the liquid storage cavity 41 with the inner wall of the housing 4, the radial sidewalls of the bearings, and the outer wall of the spindle 1, and minimize the friction between the spindle 1 and the bearings, improving the smoothness of rotation. In this embodiment, the target thermal expansion coefficient of the expanding liquid must be at least greater than that of water. The design can be adjusted according to the actual application area, wellhead characteristics, and needs. Theoretically, the larger the coefficient, the better, as a higher coefficient of thermal expansion is more susceptible to temperature changes. For example, in this embodiment, silicone oil can be selected as the expanding liquid. The contact 31 can be made of a material that can undergo elastic deformation, and can be, but is not limited to, rubber. In this embodiment, the contact 31 can also be set as a sealing sleeve. When the silicone oil is heated and expands, it will squeeze the contact 31, thereby increasing its gripping effect on the spindle 1 and increasing the friction between the two. The contact stress is used to decelerate the speed. At the same time, the silicone oil can also reduce the wear of the contact 31 and extend its service life.

[0051] Further, see Appendix Figure 2 and attached Figure 4 The jet cutting acidizing tool for coiled tubing provided in this embodiment further includes a movable component 6 in a specific implementation. The movable component 6 is movably sleeved on the outside of the mandrel 1 adjacent to the liquid storage cavity 41 so as to be able to reciprocate along the axial direction of the mandrel 1. The liquid storage cavity 41 has an opening at least on one side facing the movable component 6 so that the expanding liquid can drive the movable component 6 to move along the axial direction of the mandrel 1 when heated and expanded.

[0052] Understandably, in order to release or buffer the pressure generated by the thermal expansion of the expanding liquid and prevent the expanding liquid from deteriorating due to prolonged heating, a movable component 6 is provided in this embodiment. The movable component 6 is made of a rigid material, which can be, but is not limited to, metal. It can move axially along the mandrel 1 to absorb the expansion deformation of the expanding liquid and can also conduct heat. The movable component 6 can be located on the side of the liquid storage chamber 41 facing the nozzle 2 or on the side of the liquid storage chamber 41 facing the connector 5. The opening of the liquid storage chamber 41 facing the movable component 6 can be a gap inherent in the bearing itself. When the expanding liquid expands due to heating, it will spread to the movable component 6 through the bearing and push the movable component 6 to move axially along the mandrel 1. During this process, the expanding liquid comes into contact with the movable component 6 and can also transfer heat to the movable component 6 for cooling. Thus, the movement of the movable component 6 can slowly release the expansion energy and reduce the risk of the expanding liquid deteriorating due to heating.

[0053] Further, see Appendix Figure 2 and attached Figure 4 In the specific implementation of the continuous tubing jet cutting acidizing tool provided in this embodiment, the movable component 6 includes a telescopic member 61 and a balance piston 62; the telescopic member 61 and the balance piston 62 are sequentially arranged between the nozzle 2 and the deceleration component 3; wherein, the deceleration component 3 deforms to drive the balance piston 62 to move axially along the mandrel 1, and the telescopic member 61 can provide a force for the balance piston 62 to return to its original position.

[0054] Understandably, to improve the service life of the jet cutting acidizing tool for coiled tubing, in this embodiment, the movable component 6 is configured to include a telescopic member 61 and a balance piston 62. The telescopic member 61 is capable of elastic deformation and can be, but is not limited to, a spring, a rubber sleeve, etc. The balance piston 62 is a rigid cylindrical structure and can be, but is not limited to, a metal material. The telescopic member 61 is located on the side of the balance piston 62 away from the liquid storage chamber 41. When the expanding liquid is heated and expands, it drives the balance piston 62 to move, thus compressing the telescopic member 61. When the temperature of the expanding liquid decreases, its volume will shrink, and the telescopic member 61 will elastically reset and drive the balance piston 62 back to its original position, waiting for the next deceleration engagement. Furthermore, to maintain the stability of the telescopic member 61, in this embodiment, a piston seat 63 can be provided on the side of the telescopic member 61 facing the nozzle connection seat 12. The piston seat 63 is fixedly connected to the housing 4 to maintain stability and provide stable resistance to the telescopic member 61.

[0055] Accordingly, see Appendix Figure 2 and attached Figure 5In the specific implementation of the continuous tubing jet cutting acidizing tool provided in this embodiment, the contact member 31 includes a first spacer 311 and a second spacer 312 that are sequentially sleeved together; the inner and outer walls of the first spacer 311 are provided with receiving grooves 313, and the extending direction of the receiving grooves 313 is the same as the liquid outlet direction of the first nozzle 21.

[0056] Understandably, to improve the smoothness of the rotation of the nozzle 2 and the spindle 1 and prevent jamming, in this embodiment, the contact element 31 is configured to include a first spacer 311 and a second spacer 312 that are sequentially nested together. Both the first spacer 311 and the second spacer 312 are made of elastic material. The double-layer configuration can increase the filling space and uniformity of the filling position of the expanding liquid, and also make the contact element 31 more evenly squeezed by the evenly distributed expanding liquid, preventing damage caused by frequent squeezing of specific positions. In this embodiment, a receiving groove 313 is provided on the inner wall of the first spacer 311, so that if particles enter between the housing 4 and the spindle 1 during the rotation of the spindle 1, they can be contained by the receiving groove 313 as the spindle 1 rotates, avoiding jamming of the spindle 1 and improving the smoothness of rotation; the receiving groove 313 on the outer wall of the first spacer 311 can increase the filling amount of the expanding liquid and improve the deceleration effect.

[0057] Further, see Appendix Figure 2 and attached Figure 4 In the specific implementation of the continuous tubing jet cutting acidizing tool provided in this embodiment, the connector 5 is provided with a connecting cylinder 51, which is used to connect the jet channel 11; a second telescopic member 7 is movably sleeved on the outside of the connecting cylinder 51, which can affect the movement of the connecting cylinder 51 toward the nozzle 2.

[0058] It is understandable that when the coiled tubing is connected to the acidizing tool using a jet cutting tool to start injection, it will impact and vibrate towards the nozzle 2 under the action of the fluid. Therefore, in order to reduce the vibration of the coiled tubing acidizing tool during the injection process, in this embodiment, a connecting cylinder 51 and a second telescopic member 7 are provided in conjunction with the connector 5. When the connecting cylinder 51 is subjected to an impact force and moves towards the nozzle 2 or has a tendency to move, the second telescopic member 7 can absorb the movement or tendency to move and reset the connecting cylinder 51, thereby reducing vibration. The connecting cylinder 51 is a rigid cylinder with openings at both ends. Its end facing the nozzle 2 can be connected to the mandrel 1 through the mounting ball seat 71. This setting is easily understood by those skilled in the art and will not be described in detail here. The second telescopic component 7 is sleeved outside the connecting cylinder 51, and a nut seat 72 is provided on the outer side of the connecting cylinder 51 at the end of the connector 5 facing the nozzle 2, so that the two ends of the telescopic component 7 can respectively abut against the inner wall of the connector 5 and the nut seat 72. Therefore, when the connecting cylinder 51 is impacted and moves towards the nozzle 2 or has a tendency to move, the second telescopic component 7 is compressed, which plays a buffering role, effectively reducing vibration and extending the service life of the device. The second telescopic component 7 can be, but is not limited to, a spring, a rubber sleeve, or other structure that can undergo elastic deformation.

[0059] Further, see Appendix Figure 2 In this embodiment, the jet cutting acidizing tool for coiled tubing is provided with a pressure relief channel 52 inside the connector 5. One end of the pressure relief channel 52 is connected to the liquid storage chamber 41, and the other end is connected to the outside of the jet cutting acidizing tool for coiled tubing.

[0060] Understandably, to improve the safety of the jet cutting acidizing tool for coiled tubing, a pressure relief channel 52 is provided inside the connector 5 in this embodiment. When the telescopic member 61 is compressed to its limit and can no longer absorb more energy from the expanding liquid, the pressure relief channel 52 can guide the expanding liquid outward to relieve pressure, preventing excessive energy from the expanding liquid from causing a safety accident. It is easy to understand that the pressure relief channel 52 is connected to the liquid storage chamber 41 via the bearing 41. The pressure relief channel 52 is located inside the connector 5, and its extension direction can be along the axial direction of the mandrel 1 or around the axial direction of the mandrel 1. The relatively long channel design achieves slow pressure relief and cooling.

[0061] Further, see Appendix Figure 2 In this embodiment, the jet cutting acidizing tool for continuous tubing has an opening on the outer wall of the connector 5, which is connected to the pressure relief channel 52, and a screw 53 is provided in the opening.

[0062] Understandably, to ensure the relative sealing of the inside of the continuous tubing acidizing tool and to achieve slow pressure relief in the pressure relief channel 52, an opening is provided on the outer wall of the connector 5 to communicate with the pressure relief channel 52, so that the expanding liquid can be released through the pressure relief channel 52 and the opening to achieve pressure relief. However, if the pressure relief is too fast, it will affect the deceleration effect. Therefore, in this embodiment, a screw 53 is provided in the opening, and a relative seal is achieved at the opening through threaded engagement, reducing the rate of pressure relief, achieving slow pressure relief, and ensuring the deceleration effect.

[0063] Further, see Appendix Figure 2 and attached Figure 4 The continuous tubing jet cutting acidizing tool provided in this embodiment further includes a sealing assembly 8 in a specific implementation; the sealing assembly 8 is disposed on the side of the second bearing 43 away from the liquid storage chamber 41, and the pressure relief channel 52 is disposed on the side of the sealing assembly 8 away from the mandrel 1 in the radial direction; wherein, the second bearing 43 is located on the side of the liquid storage chamber 41 away from the nozzle 2.

[0064] Understandably, in order to prevent the pressure relief channel 52 from entering the mandrel 1 and affecting the jet fluid, a sealing component 8 is provided in this embodiment. The sealing component 8 is sleeved on the side of the second bearing 43 facing the connector 5 and is fitted onto the outside of the mandrel 1 to seal the side of the second bearing 43 facing the connector 5. This allows the expanding liquid to be discharged and depressurized out of the device only through the pressure relief channel 52, without overflowing to the connection between the mandrel 1 and the mounting ball seat 71 and the connecting cylinder 51, and thus preventing seepage into the mandrel 1. This effectively ensures the quality of the fluid in the jet channel 11 and prevents it from affecting the acidification operation of the production layer. In this embodiment, the sealing component 8 can be in the form of a lip seal 81 and a sealing gasket ring 82, occupying the space between the inner wall of the connector 5 and the outer wall of the mandrel 1, and using the interference compression elastic pre-tightening at both ends of the lip seal 81 to effectively improve the sealing performance.

[0065] Example 2

[0066] This embodiment provides an acidification system, which includes at least one of the aforementioned jet cutting acidification tools for continuous tubing.

[0067] It is understood that the jet cutting acidizing tool for coiled tubing is the same as the jet cutting acidizing tool for coiled tubing described in Example 1. Its specific structure and working principle are detailed in Example 1 and will not be elaborated upon here. The acidizing steps using the jet cutting acidizing tool for coiled tubing in this example are as follows:

[0068] After shutting in the well, the coiled tubing is run into the target well section using a jet cutting acidizing tool. Propellant is injected into the tubing to begin perforation. After perforation is completed, the perforation hole is pressurized to achieve fracturing, breaking open the formation and creating fractures. Acid is then pumped into the coiled tubing using the jet cutting acidizing tool, allowing the acid to enter the fractures for deep acidizing. After the target well section is acidized, the coiled tubing is pulled up to replace the well section, and the above operation is repeated.

[0069] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A jet cutting acidizing tool for coiled tubing, characterized by, It comprises: a mandrel, which is hollow inside to form a jet channel; a nozzle, which is arranged at a first end of the mandrel and communicates with the jet channel, and has two first nozzles arranged oppositely in a radial direction thereof, the first nozzles being capable of discharging liquid along an axial direction of the nozzle to rotate the mandrel along the axial direction of the mandrel with the discharging of the first nozzles; and at least one second nozzle arranged at an end of the nozzle away from the mandrel; a deceleration assembly, which is arranged outside the mandrel along the axial direction of the mandrel, and is capable of increasing friction with the mandrel in response to an increase in a rotating speed of the mandrel.

2. The jet cutting and acidizing tool for coiled tubing according to claim 1, further comprising a liquid storage cavity arranged along the axial direction of the mandrel.

3. The jet cutting and acidizing tool for coiled tubing according to claim 2, further comprising a movable assembly movably sleeved outside the mandrel adjacent to the liquid storage cavity to be capable of reciprocating along the axial direction of the mandrel.

4. The jet cutting and acidizing tool for coiled tubing according to claim 3, wherein the movable assembly comprises a telescopic member and a balance piston, the telescopic member and the balance piston are arranged in sequence between the nozzle and the deceleration assembly, the deceleration assembly is capable of driving the balance piston to move along the axial direction of the mandrel, and the telescopic member is capable of providing a force for returning the balance piston.

5. The jet cutting and acidizing tool for coiled tubing according to claim 2, wherein the contact member comprises a first spacer sleeve and a second spacer sleeve sleeved in sequence, and the inner wall and the outer wall of the first spacer sleeve are both provided with accommodating grooves, the extending direction of the accommodating grooves is the same as the discharging direction of the first nozzles.

6. The jet cutting and acidizing tool for coiled tubing according to claim 2, further comprising a connector arranged at an end of the mandrel away from the nozzle, the connector is used to communicate with a liquid supply pipe, and a connecting barrel is arranged in the connector to communicate with the jet channel.

7. The jet cutting and acidizing tool for coiled tubing according to claim 6, wherein a pressure relief flow channel is arranged in the connector, one end of the pressure relief flow channel communicates with the liquid storage cavity, and the other end of the pressure relief flow channel communicates to the outside of the jet cutting and acidizing tool for coiled tubing, and the jet cutting and acidizing tool for coiled tubing further comprises a shell, the shell is sleeved outside the mandrel, and the shell is fixedly connected with the connector. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 8.The coiled tubing jet cutting acidizing tool according to claim 7, characterized in that: a hole is arranged on the outer wall of the joint, the hole is connected with the pressure relief flow channel, and a screw is arranged in the hole. 9.The coiled tubing jet cutting acidizing tool according to claim 7, characterized in that: the liquid storage cavity is respectively provided with a first bearing and a second bearing at two axial ends of the mandrel; a sealing assembly is arranged on a side of the second bearing away from the liquid storage cavity, and the pressure relief flow channel is arranged on a side of the sealing assembly away from the mandrel in the radial direction of the mandrel; wherein the second bearing is located on a side of the liquid storage cavity away from the nozzle.

10. An acidification system characterized by, It comprises: at least one coiled tubing jet cutting acidizing tool according to any one of claims 1-9.

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