Horizontal well staged fracturing device and surface treatment method for ball seat and shell assembly

Abstract

The invention provides a horizontal well staged fracturing device and a surface treatment method of a ball seat and a shell assembly, the horizontal well staged fracturing device comprises at least one section of fracturing module, the fracturing module comprises a shell assembly, a sliding sleeve, a ball seat and a soluble fracturing ball, and the circumferential side wall of the shell assembly is provided with at least one set of sand blasting openings; the sliding sleeve is movably arranged in the shell assembly and can slide in the axial direction of the shell assembly, the ball seat is arranged in the sliding sleeve and moves along with the sliding sleeve, the ball seat is provided with a communicating flow channel, the inner side wall of the communicating flow channel is provided with a hardened layer formed through boriding treatment, and at least one part of the shell assembly is provided with a carburized layer formed through carburizing treatment. The soluble fracturing ball enters the shell assembly from the liquid inlet of the shell assembly and abuts against the inner side wall of the communicating flow channel. The technical problems that in the prior art, after a drillable ball seat is eroded and expanded, a sand blasting opening is difficult to open, and a shell is prone to being eroded and fractured are solved.

Description

Technical Field

[0001] The invention relates to the technical field of oilfield development, and in particular to a horizontal well staged fracturing device and a surface treatment method for a ball seat and a shell assembly. Background Art

[0002] In the existing technology, the staged fracturing technology of horizontal wells is an important means for the efficient development of low-permeability oil and gas reservoirs. Among them, the "open hole packer + sliding sleeve" graded volume fracturing technology for horizontal wells is the most important one. It has the characteristics of large contact area with oil and gas reservoirs, natural selection of sweet spots, and high operating efficiency. It is widely used in oil fields at home and abroad. Among them, the multi-stage fracturing sleeve is one of the most critical tools in this technology. At present, the multi-stage fracturing sleeves used in the "open hole packer + sliding sleeve" technology for horizontal wells at home and abroad all rely on the differential drillable ball seat to drive the inner sleeve downward, open the sandblasting port of the shell, and then communicate with the formation. The open hole staged volume fracturing has a large displacement and a large amount of sand. Therefore, there are problems such as the sleeve body is easily eroded and fractured, and the drillable ball seat is eroded and expanded by the sand-carrying fluid, which makes it difficult to open the sandblasting port.

[0003] Therefore, there are technical problems in the prior art that the drillable ball seat is eroded and expanded, which makes it difficult to open the sandblasting port, and the shell is easily eroded and fractured. Summary of the invention

[0004] The main purpose of the present invention is to provide a horizontal well staged fracturing device and a surface treatment method for a ball seat and a shell assembly to solve the problems in the prior art that the drillable ball seat is eroded and expanded, resulting in difficulty in opening the sandblasting port, and the shell is easily eroded and fractured.

[0005] In order to achieve the above-mentioned purpose, according to one aspect of the present invention, a horizontal well staged fracturing device is provided, which includes at least one stage of fracturing module, and the fracturing module includes a shell assembly, a sleeve, a ball seat and a soluble fracturing ball, wherein the circumferential side wall of the shell assembly has at least one group of sandblasting ports; the sleeve is movably arranged in the interior of the shell assembly and can slide along the axial direction of the shell assembly, and the sleeve has a blocking position for blocking the sandblasting ports and a avoidance position for avoiding the sandblasting ports; the ball seat is arranged in the interior of the sleeve and moves with the sleeve, the ball seat has a connecting flow channel, both ends of the connecting flow channel are connected to the interior of the shell assembly, the inner side wall of the connecting flow channel has a hardened layer formed by boronizing treatment, and at least a part of the shell assembly has a carburized layer formed by carburizing treatment; the soluble fracturing ball enters the shell assembly from the liquid inlet of the shell assembly and abuts against the inner side wall of the connecting flow channel.

[0006] Furthermore, the thickness of the hardened layer is between 0.15 mm and 0.5 mm; and / or the hardness of the hardened layer is between HV 0.1 1200 to HV 0.11400; and / or the strength of the hardened layer is between 34KN and 36KN; and / or the hardness of the carburized layer is above HRC65; and / or the thickness of the carburized layer is between 1.2mm and 1.5mm.

[0007] Further, the ball seat is made of QT500-7 ductile iron, and / or at least a portion of the housing assembly is made of 20CrMnTi.

[0008] Furthermore, the fracturing module also includes at least one starting shear pin, which is arranged between the shell assembly and the sliding sleeve, and the two ends of the starting shear pin are respectively connected to the shell assembly and the sliding sleeve; when the soluble fracturing ball is not dissolved, the soluble fracturing ball divides the connecting flow channel into two unconnected sections; when the starting shear pin breaks, the sliding sleeve drives the ball seat and the soluble fracturing ball to switch from the blocking position to the avoidance position.

[0009] Furthermore, the fracturing module also includes a check ring, which is made of elastic material. The check ring is arranged on the circumferential outer wall of the sleeve. The inner wall of the shell assembly has a locking groove that cooperates with the check ring. When the sleeve moves to the avoidance position, the check ring cooperates with the locking groove to limit the sleeve.

[0010] Further, the shell assembly includes a main body and a connecting joint, wherein the circumferential side wall of the main body has at least one sandblasting port, and the sliding sleeve is movably arranged inside the main body; there are two connecting joints, the liquid inlet of the main body and the liquid outlet of the main body are respectively provided with a connecting joint, one of the connecting joint of the liquid outlet of the main body and the sliding sleeve has at least one anti-rotation protrusion, and the other has at least one anti-rotation groove, and when the sliding sleeve is in the avoidance position, the anti-rotation protrusion cooperates with the anti-rotation groove to prevent the sliding sleeve from rotating relative to the shell assembly.

[0011] Furthermore, when the fracturing module has multiple sections, the multiple sections are connected in sequence, and the diameter of the soluble fracturing ball of the downstream fracturing module in two adjacent sections of the fracturing module is smaller than the diameter of the soluble fracturing ball of the upstream fracturing module.

[0012] Furthermore, the connecting flow channel includes a guide section and a main flow section connected in sequence, the guide section is located upstream of the main flow section, the diameter of the guide section is larger than the diameter of the main flow section, and the soluble fracturing ball is located at the connection between the guide section and the main flow section.

[0013] Furthermore, when the fracturing module is multi-section, the diameters of the connecting flow channels of different fracturing modules are different. When the diameter of the mainstream section of one of the fracturing modules is less than or equal to 60 mm, the diameter of the mainstream section of the fracturing module located upstream thereof increases by 3 mm; and / or when the diameter of the mainstream section of one of the fracturing modules is greater than 60 mm and less than or equal to 78 mm, the diameter of the mainstream section of the fracturing module located upstream thereof increases by 3.5 mm; and / or when the diameter of the mainstream section of one of the fracturing modules is greater than 78 mm, the diameter of the mainstream section of the fracturing module located upstream thereof increases by 4 mm.

[0014] Furthermore, when the diameter of the mainstream section is less than or equal to a preset value, the connecting flow channel also includes a leakage section, which is connected to the end of the mainstream section away from the guide section, the diameter of the leakage section is larger than the diameter of the mainstream section, and the diameter of the leakage section gradually increases in the direction away from the mainstream section; the guide section includes a first guide part and a second guide part connected in sequence, the end of the second guide part away from the first guide part is connected to the mainstream section, the diameter of the first guide part is larger than the diameter of the second guide part, and the diameter of the first guide part gradually decreases in the direction approaching the second guide part.

[0015] Furthermore, a step surface is provided at the connection between the second flow guide portion and the main flow section, the soluble fracturing ball abuts against the step surface, at least a portion of the soluble fracturing ball is located in the main flow section, and at least another portion of the soluble fracturing ball is located in the second flow guide portion.

[0016] Further, the diameter of each part of the second flow guide portion is the same; and / or the diameter of each part of the main flow section is the same.

[0017] Furthermore, the angle between the first guide part and the second guide part is greater than or equal to 25° and less than or equal to 30°; and / or the angle between the discharge section and the main flow section is greater than or equal to 35° and less than or equal to 45°; and / or the inner diameter of the main flow section is Amm, the inner diameter of the second guide part is B, and B=(A+4.5)mm; and / or the inner diameter of the main flow section is Amm, the length of the second guide part is C, and C=78-tan63°*(86.5-A) / 2, the length of the first guide part is D, and D=tan63°*(86.5-A) / 2.

[0018] Further, when the diameter of the main flow section is greater than a preset value, the diameter of the guide section gradually decreases in a direction approaching the main flow section, and the angle between the guide section and the main flow section is 45°.

[0019] According to another aspect of the present invention, a surface treatment method for a ball seat is provided. The ball seat of the fracturing module in the above-mentioned horizontal well staged fracturing device uses the surface treatment method for the ball seat to form a hardened layer. The surface treatment method for the ball seat includes: placing the ball seat in a heat-resistant sealed tank, the heat-resistant sealed tank is filled with boron powder and an activator, and the boron powder and the activator coat the ball seat; placing the heat-resistant sealed tank in a high-temperature heating furnace, and heating the heat-resistant sealed tank in the high-temperature heating furnace, the ball seat reacts with the boron powder under the action of the activator, and the surface of the ball seat is subjected to boriding treatment to form a hardened layer.

[0020] Furthermore, in the process of placing the ball seat in the heat-resistant sealed can, open the sealing cover of the heat-resistant sealed can, spread a preset thickness of boron powder in the heat-resistant sealed can, place the ball seat at the center of the boron powder in the heat-resistant sealed can, evenly spread the boron powder on the periphery of the ball seat and compact it, evenly spread the preset thickness of boron powder on the top of the ball seat and compact it, and then cover it with the sealing cover.

[0021] Further, before the surface of the ball seat is subjected to boronizing treatment, the ball seat is subjected to sandblasting treatment; and / or after the surface of the ball seat is subjected to boronizing treatment, the ball seat is subjected to sandblasting treatment.

[0022] Furthermore, after placing the heat-resistant sealed can in the high-temperature heating furnace, the pressure inside the high-temperature heating furnace is evacuated to 0 Pa and deoxygenation is performed, the high-temperature heating furnace is dehumidified and argon gas is flushed into the high-temperature heating furnace until the pressure inside the high-temperature heating furnace reaches 1 Pa, and the heat-resistant sealed can is heated by the high-temperature heating furnace to cause the ball seat to react with the boron powder.

[0023] Furthermore, when the heat-resistant sealed can is heated by a high-temperature heating furnace, the heat-resistant sealed can is first heated to 500°C and kept warm for 2 hours, then the heat-resistant sealed can is preheated to a certain temperature, and then heated to 960°C and kept warm for 12 hours, the ball seat is surface-coated, and finally naturally cooled to room temperature.

[0024] According to another aspect of the present invention, a surface treatment method for a shell component is provided. The shell component of the fracturing module in the above-mentioned horizontal well staged fracturing device uses the surface treatment method for the shell component to form a carburized layer. The surface treatment method for the shell component includes: forming a sandblasting port on the shell component by wire cutting, carburizing at least a portion of the shell component to form a carburized layer, placing the portion cut off during the wire cutting process into the sandblasting port, spot welding the outer surface of the connection between the sandblasting port and the cut off portion, and then grinding the inner wall surface of the shell component.

[0025] Applying the technical solution of the present invention, the horizontal well staged fracturing device in this solution includes at least one section of fracturing module, and the fracturing module includes a shell assembly, a sleeve, a ball seat and a soluble fracturing ball, wherein the circumferential side wall of the shell assembly has at least one group of sandblasting ports; the sleeve is movably arranged inside the shell assembly and can slide along the axial direction of the shell assembly, and the sleeve has a blocking position for blocking the sandblasting ports and a avoidance position for avoiding the sandblasting ports; the ball seat is arranged inside the sleeve and moves with the sleeve, the ball seat has a connecting flow channel, both ends of the connecting flow channel are connected to the interior of the shell assembly, the inner side wall of the connecting flow channel has a hardened layer formed by boronizing treatment, and at least a part of the shell assembly has a carburized layer formed by carburizing treatment; the soluble fracturing ball enters the shell assembly from the liquid inlet of the shell assembly and abuts against the inner side wall of the connecting flow channel.

[0026] The present invention allows a soluble fracturing ball to enter the shell assembly from the liquid inlet of the shell assembly, the soluble fracturing ball contacts the ball seat and is limited by the inner side wall of the connecting flow channel, the soluble fracturing ball blocks the connecting flow channel of the ball seat, and under the fluid pressure inside the shell assembly, the soluble fracturing ball drives the ball seat and the sliding sleeve to move together, so that the sliding sleeve switches from a blocking position for blocking the sandblasting port to a avoiding position for avoiding the sandblasting port, and the fracturing sand entering from the liquid inlet of the shell assembly communicates with the formation through the sandblasting port, and by carburizing at least a portion of the shell assembly to form a carburized layer, the hardness and carburized layer thickness of the shell assembly meet the requirements, thereby preventing the shell assembly from being broken by the fracturing sand; the ball seat is subjected to boronizing treatment to form a surface hardening layer, so that the hardness and boronizing thickness of the end face and inner side wall of the connecting flow channel of the ball seat meet the requirements, thereby reducing the erosion of the ball seat by the fracturing sand, and preventing the ball seat from being eroded and expanded by the fracturing sand, thereby causing difficulty in opening the sandblasting port. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The drawings constituting a part of the present application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0028] Figure 1 A schematic structural diagram of a first stage fracturing module of a horizontal well staged fracturing device according to an optional embodiment of the present invention is shown;

[0029] Figure 2 A schematic cross-sectional structure diagram of the main body of the shell assembly of the fracturing module of the present invention is shown;

[0030] Figure 3 A schematic diagram showing the shape of the sandblasting port of the housing assembly of the fracturing module of the present invention is shown;

[0031] Figure 4 A schematic cross-sectional structure diagram of the housing assembly of the fracturing module of the present invention at the locking groove position is shown;

[0032] Figure 5 A schematic structural diagram of the inner side wall of the connecting flow channel of the ball seat of the present invention is shown.

[0033] The above drawings include the following reference numerals:

[0034] 10. Shell assembly; 11. Main body; 111. Sandblasting port; 112. Locking groove; 12. Connecting joint; 20. Sleeve; 30. Ball seat; 31. Connecting flow channel; 311. Guide section; 3111. First guide part; 3112. Second guide part; 312. Main flow section; 313. Discharge section; 314. Step surface; 40. Soluble fracturing ball; 50. Start shear pin; 60. Check ring. DETAILED DESCRIPTION

[0035] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means intended to limit the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0036] In order to solve the problems in the prior art that the drillable ball seat is eroded and expanded, which leads to difficulty in opening the sandblasting port, and the shell is easily eroded and fractured, the present invention provides a horizontal well staged fracturing device and a surface treatment method for a ball seat and a shell assembly.

[0037] like Figures 1 to 5 As shown, the horizontal well staged fracturing device includes at least one section of fracturing module, and the fracturing module includes a shell component 10, a sleeve 20, a ball seat 30 and a soluble fracturing ball 40, wherein the circumferential side wall of the shell component 10 has at least one group of sandblasting ports 111; the sleeve 20 is movably arranged inside the shell component 10 and can slide along the axial direction of the shell component 10, and the sleeve 20 has a blocking position for blocking the sandblasting ports 111 and a avoidance position for avoiding the sandblasting ports 111; the ball seat 30 is arranged inside the sleeve 20 and moves with the sleeve 20, the ball seat 30 has a connecting flow channel 31, both ends of the connecting flow channel 31 are connected to the inside of the shell component 10, the inner side wall of the connecting flow channel 31 has a hardened layer formed by boronizing treatment, and at least a part of the shell component 10 has a carburized layer formed by carburizing treatment; the soluble fracturing ball 40 enters the shell component 10 from the liquid inlet of the shell component 10 and abuts against the inner side wall of the connecting flow channel 31.

[0038] In the present invention, the soluble fracturing ball 40 enters the shell assembly 10 from the liquid inlet of the shell assembly 10, the soluble fracturing ball 40 contacts the ball seat 30 and is limited by the inner side wall of the connecting flow channel 31, the soluble fracturing ball 40 blocks the connecting flow channel 31 of the ball seat 30, and under the fluid pressure inside the shell assembly 10, the soluble fracturing ball 40 drives the ball seat 30 and the sliding sleeve 20 to move together, so that the sliding sleeve 20 switches from the blocking position of blocking the sandblasting port 111 to the avoidance position of avoiding the sandblasting port 111, and the soluble fracturing ball 40 entering the shell assembly 10 from the liquid inlet The fracturing sand communicates with the formation through the sandblasting port 111. By carburizing at least a portion of the shell assembly 10 to form a carburized layer, the hardness and thickness of the carburized layer of the shell assembly 10 meet the requirements, thereby preventing the shell assembly 10 from being broken by the fracturing sand. The ball seat 30 is boronized to form a surface hardened layer, so that the hardness and boronized thickness of the end face and inner wall of the connecting flow channel 31 of the ball seat 30 meet the requirements, thereby reducing the erosion of the ball seat 30 by the fracturing sand, and preventing the ball seat 30 from being eroded and expanded by the fracturing sand, thereby preventing the sandblasting port 111 from being difficult to open.

[0039] In this application, the thickness of the hardened layer is between 0.15 mm and 0.5 mm; the hardness of the hardened layer is between HV 0.1 1200 to HV 0.1 1400; the strength of the hardened layer is between 34KN and 36KN; in this way, the hardened layer formed on the surface of the ball seat 30 reaches the thickness and hardness requirements, reducing the erosion of the ball seat 30 by the fracturing sand.

[0040] In the present application, the hardness of the carburized layer is above HRC65, and the thickness of the carburized layer is between 1.2 mm and 1.5 mm. In this way, the carburized layer formed on the surface of the shell component 10 meets the thickness and hardness requirements, preventing the shell component 10 from being broken by the fracturing sand.

[0041] In the present application, the ball seat 30 is made of QT500-7 ductile iron, and at least a portion of the housing assembly 10 is made of 20CrMnTi. Thus, the material of the ball seat 30 can meet the requirements after boronizing treatment, and the material of at least a portion of the housing assembly 10 can meet the requirements after carburizing treatment.

[0042] It should be noted that, in this embodiment, Figure 2 and Figure 3 As shown, three groups of sandblasting ports 111 are provided, and the three groups of sandblasting ports 111 are evenly and spacedly arranged in the circumferential direction of the housing assembly 10, and each group of sandblasting ports 111 is provided with two sandblasting ports 111, and the two sandblasting ports 111 are arranged side by side in the circumferential direction of the housing assembly 10. Preferably, the flow area ratio of the sandblasting ports 111 to the flow area of ​​the main channel is 1.5:1, wherein the main channel is the inner diameter of the body portion 11.

[0043] like Figure 1As shown, the fracturing module also includes at least one starting shear pin 50, which is arranged between the shell assembly 10 and the sleeve 20, and the two ends of the starting shear pin 50 are respectively connected to the shell assembly 10 and the sleeve 20; when the soluble fracturing ball 40 is not dissolved, the soluble fracturing ball 40 separates the connecting flow channel 31 into two sections that are not connected to each other; when the starting shear pin 50 is broken, the sleeve 20 drives the ball seat 30 and the soluble fracturing ball 40 to switch from the blocking position to the avoidance position. In this way, the starting shear pins 50 are connected to the shell assembly 10 and the sliding sleeve 20. When the soluble fracturing ball 40 enters the shell assembly 10, the soluble fracturing ball 40 abuts against the inner wall of the connecting flow channel 31. The soluble fracturing ball 40 divides the connecting flow channel 31 into two sections that are not connected to each other. The fluid pressure inside the shell assembly 10 causes the starting shear pins 50 to break under force. The soluble fracturing ball 40 is forced to drive the ball seat 30 and the sliding sleeve 20 to move together in the shell assembly 10. The sliding sleeve 20 drives the ball seat 30 and the soluble fracturing ball 40 to switch from the blocking position to the avoidance position.

[0044] like Figure 1 As shown, the fracturing module further includes a check ring 60, which is made of elastic material and is sleeved on the circumferential outer side wall of the sleeve 20. The inner side wall of the housing assembly 10 has a locking groove 112 that cooperates with the check ring 60. When the sleeve 20 moves to the avoidance position, the check ring 60 cooperates with the locking groove 112 to limit the position of the sleeve 20. In this way, the check ring 60 cooperates with the locking groove 112 to prevent the sleeve 20 from switching from the avoidance position back to the blocking position, thereby preventing the sandblasting port 111 from being blocked.

[0045] It should be noted that, in the present embodiment, the check ring 60 is an elastic open ring, that is, the check ring 60 is an annular structure with a notch, and the circumferential outer wall of the sleeve 20 has a check ring mounting groove, and the check ring 60 is installed in the check ring mounting groove. When the sleeve 20 is installed in the shell assembly 10, the check ring 60 in the check ring mounting groove is in an elastic compression state, and the check ring 60 does not extend out of the circumferential outer wall of the sleeve 20 to ensure that the sleeve 20 can slide in the shell assembly 10. When the sleeve 20 switches to the avoidance position, the check ring 60 switches from the elastic compression state to the free extension state, and the check ring 60 extends into the locking groove 112 of the shell assembly 10 to prevent the sleeve 20 and the shell assembly 10 from moving in the axial direction of the sleeve 20.

[0046] like Figure 1As shown, the shell assembly 10 includes a main body 11 and a connecting joint 12, wherein the circumferential side wall of the main body 11 has at least one sandblasting port 111, and the sliding sleeve 20 is movably arranged inside the main body 11; there are two connecting joints 12, and the liquid inlet of the main body 11 and the liquid outlet of the main body 11 are respectively provided with a connecting joint 12, and one of the connecting joint 12 of the liquid outlet of the main body 11 and the sliding sleeve 20 has at least one anti-rotation protrusion, and the other has at least one anti-rotation groove. When the sliding sleeve 20 is located in the avoidance position, the anti-rotation protrusion cooperates with the anti-rotation groove to prevent the sliding sleeve 20 from rotating relative to the shell assembly 10.

[0047] It should be noted that, in the present embodiment, one end of the sliding sleeve 20 facing the connecting joint 12 of the liquid outlet of the main body 11 has two anti-rotation protrusions, and the connecting joint 12 of the liquid outlet of the main body 11 has two anti-rotation grooves. Of course, in other embodiments, one end of the sliding sleeve 20 facing the connecting joint 12 of the liquid outlet of the main body 11 may have an anti-rotation groove, and the connecting joint 12 of the liquid outlet of the main body 11 may have an anti-rotation protrusion. The number of anti-rotation protrusions and anti-rotation grooves may also be set as required.

[0048] It should be noted that, in this embodiment, the main body 11 and the two connecting joints 12 are connected by threads, the outer surface of the ball seat 30 is provided with connecting threads, and the ball seat 30 is connected to the threads of the inner wall surface of the sliding sleeve 20 by left-handed threads.

[0049] In the present application, when the fracturing module is multi-stage, the multi-stage fracturing modules are connected in sequence, and the diameter of the soluble fracturing ball 40 of the fracturing module located downstream of the two adjacent fracturing modules is smaller than the diameter of the soluble fracturing ball 40 of the fracturing module located upstream. In this way, the soluble fracturing ball 40 located downstream of the two adjacent fracturing modules enters the interior of the shell assembly 10 before the soluble fracturing ball 40 of the fracturing module located upstream, so as to achieve staged fracturing.

[0050] It should be noted that, in this embodiment, the fracturing module has 19 sections to meet the requirement of 20 levels of open hole pressure distribution. Of course, the number of sections of the fracturing module can be set according to actual needs.

[0051] It should be noted that, in the present embodiment, the sizes of the connecting flow channel 31 of the ball seat 30 of each fracturing module are different. The diameter of the connecting flow channel 31 of the ball seat 30 of the downstream fracturing module in two adjacent fracturing modules is smaller than the diameter of the connecting flow channel 31 of the ball seat 30 of the upstream fracturing module, so that each size of the soluble fracturing ball 40 can be limited on the corresponding ball seat 30 of each fracturing module.

[0052] like Figure 1 and Figure 5As shown, the communication flow channel 31 includes a diversion section 311 and a main flow section 312 connected in sequence, the diversion section 311 is located upstream of the main flow section 312, the diameter of the diversion section 311 is larger than the diameter of the main flow section 312, and the soluble fracturing ball 40 is located at the connection between the diversion section 311 and the main flow section 312. In this way, the diversion section 311 can guide the fracturing sand to prevent the fracturing sand from having too much impact on the ball seat 30 when passing through the ball seat 30.

[0053] It should be noted that, in the present embodiment, since the fracturing sand reaches the fracturing module with the sandblasting port 111 opened after passing through the multi-stage fracturing module located upstream, the ball seat 30 of the multi-stage fracturing module located upstream is impacted by the fracturing sand. If the impact is too great and causes the diameter of the connecting flow channel 31 of the ball seat 30 to increase, the inner side wall of the connecting flow channel 31 cannot limit the soluble fracturing ball 40, the sleeve 20 of this section of the fracturing module cannot move, the sandblasting port 111 cannot be opened, and a section will be lost.

[0054] In the present application, when the fracturing module is multi-stage, the diameters of the connecting flow channels 31 of different fracturing modules are different. When the diameter of the mainstream section 312 of one of the fracturing modules is less than or equal to 60 mm, the diameter of the mainstream section 312 of the fracturing module located upstream thereof increases by 3 mm; when the diameter of the mainstream section 312 of one of the fracturing modules is greater than 60 mm and less than or equal to 78 mm, the diameter of the mainstream section 312 of the fracturing module located upstream thereof increases by 3.5 mm; when the diameter of the mainstream section 312 of one of the fracturing modules is greater than 78 mm, the diameter of the mainstream section 312 of the fracturing module located upstream thereof increases by 4 mm. In this way, the diameter of the mainstream section 312 of the downstream fracturing module of the two adjacent fracturing modules is smaller than the diameter of the mainstream section 312 of the upstream fracturing module, and as the diameter of the mainstream section 312 increases, the diameter difference of the mainstream section 312 of the two adjacent fracturing modules also increases, so as to ensure the feasibility of the actual fracturing work.

[0055] like Figure 1 and Figure 5As shown, when the diameter of the main flow section 312 is less than or equal to the preset value, the connecting flow channel 31 further includes a leakage section 313, which is connected to the end of the main flow section 312 away from the guide section 311, the diameter of the leakage section 313 is greater than the diameter of the main flow section 312, and the diameter of the leakage section 313 gradually increases in the direction away from the main flow section 312; the guide section 311 includes a first guide portion 3111 and a second guide portion 3112 connected in sequence, the end of the second guide portion 3112 away from the first guide portion 3111 is connected to the main flow section 312, the diameter of the first guide portion 3111 is greater than the diameter of the second guide portion 3112, and the diameter of the first guide portion 3111 gradually decreases in the direction close to the second guide portion 3112. In this way, the setting of the guide section 311 and the leakage section 313 on the inner side wall of the connecting flow channel 31 ensures that the erosion force of the fracturing sand on the ball seat 30 is small.

[0056] Preferably, the preset value is 78 mm.

[0057] like Figure 5 As shown, the connection between the second flow guide portion 3112 and the main flow section 312 has a step surface 314, the soluble fracturing ball 40 abuts against the step surface 314, and at least a portion of the soluble fracturing ball 40 is located in the main flow section 312, and at least another portion of the soluble fracturing ball 40 is located in the second flow guide portion 3112. In this way, the step surface 314 is used to limit the movement of the soluble fracturing ball 40 in the communication flow channel 31.

[0058] like Figure 5 As shown, the diameters of the second flow guide portion 3112 are the same at all locations; the diameters of the main flow section 312 are the same at all locations. In this way, the ball seat 30 is easy to process and the sand passing amount of the connecting flow channel 31 is guaranteed.

[0059] like Figure 5 As shown, the angle between the first flow guide portion 3111 and the second flow guide portion 3112 is greater than or equal to 25° and less than or equal to 30°; the angle between the discharge section 313 and the main flow section 312 is greater than or equal to 35° and less than or equal to 45°; the inner diameter of the main flow section 312 is Amm, the inner diameter of the second flow guide portion 3112 is B, and B=(A+4.5)mm; the inner diameter of the main flow section 312 is Amm, the length of the second flow guide portion 3112 is C, and C=78-tan63°*(86.5-A) / 2, the length of the first flow guide portion 3111 is D, and D=tan63°*(86.5-A) / 2. In this way, the structure and size setting of the inner wall surface of the connecting flow channel 31 change the flow field distribution of the sand-carrying fluid and reduce the erosion of the fracturing sand on the ball seat 30.

[0060] Preferably, in this embodiment, the angle between the first flow guiding portion 3111 and the second flow guiding portion 3112 is 27°, and the angle between the flow leakage section 313 and the main flow section 312 is 40°.

[0061] It should be noted that, in the present embodiment, the outer diameter, length, connecting thread, and step surface 314 of each ball seat 30 are all the same; the inner diameters of the main flow section 312, the first guide part 3111, the second guide part 3112, and the discharge section 313 are all different; the first guide part 3111 includes a conical guide surface, and the second guide part 3112 includes a cylindrical guide surface.

[0062] In the present application, when the diameter of the main flow section 312 is greater than a preset value, the diameter of the guide section 311 gradually decreases in the direction close to the main flow section 312, and the angle between the guide section 311 and the main flow section 312 is 45°. In this way, when the diameter of the main flow section 312 is too large and the thickness of the ball seat 30 is relatively thin, the leakage section 313 and the step surface 314 cannot be provided on the inner side wall of the connecting flow channel 31, and the guide section 311 is not provided with the first guide part 3111 and the second guide part 3112. The guide section 311 includes a conical guide surface, and the main flow section 312 includes a cylindrical guide surface. The soluble fracturing ball 40 abuts against the inner side wall of the guide section 311, and at least a part of the soluble fracturing ball 40 is in the guide section 311, and at least another part is in the main flow section 312.

[0063] The surface treatment method of the ball seat includes: placing the ball seat 30 in a heat-resistant sealed can, wherein the heat-resistant sealed can is filled with boron powder and an activator, and the boron powder and the activator cover the ball seat 30; placing the heat-resistant sealed can in a high-temperature heating furnace, and heating the heat-resistant sealed can in the high-temperature heating furnace, so that the ball seat 30 reacts with the boron powder under the action of the activator, and the surface of the ball seat 30 is subjected to boriding treatment to form a hardened layer. In this way, the ball seat 30 and the boron powder react under the action of the activator to form a hardened layer, so that the end face of the ball seat 30 and the inner side wall of the connecting flow channel 31 have good erosion resistance.

[0064] It should be noted that in the present method, since heat treatment is required during the boriding reaction, in order to control the deformation of the step surface 314 of the ball seat 30 and the connecting thread during heat treatment, the semi-finished product needs to be processed before the boriding treatment, wherein the outer diameter and length of the ball seat semi-finished product reserve sufficient processing allowance, and the end face, the inner side wall of the guide section 311, the inner side wall of the main flow section 312, and the inner side wall of the discharge section 313 are processed to the final size.

[0065] Before the surface of the ball seat 30 is subjected to boronizing treatment, the ball seat 30 is subjected to sandblasting treatment; thus, the sandblasting treatment can remove impurities on the surface of the ball seat 30, making it easier for the ball seat 30 to be subjected to boronizing treatment.

[0066] When placing the ball seat 30 in the heat-resistant sealed can, open the sealing cover of the heat-resistant sealed can, spread boron powder of a preset thickness in the heat-resistant sealed can, place the ball seat 30 at the center of the boron powder in the heat-resistant sealed can, spread boron powder evenly around the periphery of the ball seat 30 and compact it, spread boron powder evenly above the ball seat 30 and compact it, and then cover the sealing cover. In this way, the ball seat 30 reacts in the sealed can space, preventing external impurities from affecting the boronizing reaction.

[0067] Preferably, the preset thickness is 50 mm.

[0068] After placing the heat-resistant sealed can in the high-temperature heating furnace, the pressure in the high-temperature heating furnace is evacuated to 0Pa and deoxygenation is performed, the high-temperature heating furnace is dehumidified and argon gas is injected into the high-temperature heating furnace until the pressure in the high-temperature heating furnace reaches 1Pa, and the heat-resistant sealed can is heated by the high-temperature heating furnace to make the ball seat 30 react with the boron powder. In this way, the reaction is prevented from being affected by the outside world, and the normal boronizing reaction is ensured.

[0069] When the heat-resistant sealed can is heated by the high-temperature heating furnace, the heat-resistant sealed can is first heated to 500°C and kept warm for 2 hours, then the heat-resistant sealed can is preheated to a certain temperature, and then heated to 960°C and kept warm for 12 hours, the ball seat 30 is surface-boronized, and finally naturally cooled to room temperature. In this way, the high-temperature heating furnace heats the heat-resistant sealed can to ensure that the temperature of the boronizing reaction of the ball seat 30 reaches the requirement, and preheating can remove the oxide on the surface of the ball seat 30.

[0070] After the surface of the ball seat 30 is subjected to boronizing treatment, the ball seat 30 is subjected to sandblasting treatment. In this way, the ball seat 30 taken out of the high-temperature heating furnace is subjected to sandblasting treatment again to remove impurities on the surface of the ball seat 30.

[0071] Finally, the step surface and the external thread of the ball seat 30 are further processed to process the semi-finished ball seat into the finished ball seat 30 .

[0072] The surface treatment method of the shell component includes: forming a sandblasting port 111 of the shell component 10 by wire cutting, carburizing at least a portion of the shell component 10 to form a carburized layer, placing the portion cut off during the wire cutting process into the sandblasting port 111, spot welding the outer surface of the connection between the sandblasting port 111 and the cut off portion, and then grinding the inner wall surface of the shell component 10.

[0073] It should be noted that in the surface treatment method of the shell assembly 10, the main body 11 is carburized as a whole. Before carburizing, the sandblasting port 111 needs to be wire-cut and the cut part is retained to ensure that the side of the sandblasting port 111 has a high-strength carburized layer, and a 0.15mm processing allowance is reserved for the inner diameter mating surface of the main body 11.

[0074] After the carburizing treatment, the Rockwell hardness of the carburized layer of the main body 11 reaches above HRC65, the thickness of the carburized layer is 1.2-1.5mm, and the carburized layer is uniform. At the same time, the part cut by the sandblasting port 111 needs to be put back to the original position, and the outer side of the main body 11 is spot welded, and then ground to achieve the required size and accuracy.

[0075] From the above description, it can be seen that the above-mentioned embodiments of the present invention achieve the following technical effects: the present invention allows the soluble fracturing ball 40 to enter the shell assembly 10 from the liquid inlet of the shell assembly 10, the soluble fracturing ball 40 contacts the ball seat 30 and is limited by the inner side wall of the connecting flow channel 31, the soluble fracturing ball 40 blocks the connecting flow channel 31 of the ball seat 30, and under the internal fluid pressure of the shell assembly 10, the soluble fracturing ball 40 drives the ball seat 30 and the sliding sleeve 20 to move together, so that the sliding sleeve 20 switches from the blocking position of blocking the sandblasting port 111 to the avoiding position of avoiding the sandblasting port 111. The fracturing sand entering from the liquid inlet of the shell component 10 communicates with the formation through the sandblasting port 111. By carburizing at least a portion of the shell component 10 to form a carburized layer, the hardness and thickness of the carburized layer of the shell component 10 meet the requirements, thereby preventing the shell component 10 from being broken by the fracturing sand. The ball seat 30 is subjected to a boronizing treatment to form a surface hardening layer, so that the hardness and boronizing thickness of the end face and inner wall of the connecting flow channel 31 of the ball seat 30 meet the requirements, thereby reducing the erosion of the ball seat 30 by the fracturing sand, thereby preventing the ball seat 30 from being eroded and expanded by the fracturing sand, thereby preventing the sandblasting port 111 from being difficult to open.

[0076] At the same time, the body part 11 provided by the present invention has a surface hardness of more than HRC65 and a thickness of more than 1.5 mm by optimizing the material of the body part 11 and performing a reasonable surface strengthening process; by optimizing the structure of the ball seat 30, the flow field distribution of the sand-carrying liquid is changed, and the erosion of the ball seat 30 by the fracturing sand is reduced; by performing a semi-finished product boronizing treatment on the ball seat 30 and a special treatment method for finished product finishing, the hardness of the hardened layer of the ball seat 30 reaches HV 0.1 1200 to HV 0.1 1400, the thickness reaches 0.15-0.5mm, and the single-stage sand passing amount of the ball seat 30 and the shell assembly 10 reaches 100mm 3 , which not only ensures the anti-erosion performance of fracturing sand but also facilitates the later grinding.

[0077] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0078] Unless otherwise specifically stated, the relative arrangement of the parts and steps described in these embodiments, numerical expressions and numerical values ​​do not limit the scope of the present invention. At the same time, it should be understood that, for ease of description, the sizes of the various parts shown in the accompanying drawings are not drawn according to the actual proportional relationship. The technology, method and equipment known to ordinary technicians in the relevant field may not be discussed in detail, but in appropriate cases, the technology, method and equipment should be regarded as a part of the authorization specification. In all examples shown and discussed here, any specific value should be interpreted as being merely exemplary, rather than as a limitation. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters represent similar items in the following drawings, so once a certain item is defined in an accompanying drawing, it does not need to be further discussed in subsequent drawings.

[0079] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used here to describe the spatial positional relationship between a device or feature and other devices or features as shown in the figure. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figure. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

[0080] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0081] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the numbers used in this way can be interchanged where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein.

[0082] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A horizontal well staged fracturing device, characterized in that: The horizontal well staged fracturing device comprises at least one stage of fracturing module, and the fracturing module comprises: A shell assembly (10), wherein the circumferential side wall of the shell assembly (10) has at least one set of sandblasting openings (111); a sliding sleeve (20), the sliding sleeve (20) being movably arranged inside the housing component (10) and being capable of sliding along the axial direction of the housing component (10), and the sliding sleeve (20) having a blocking position for blocking the sandblasting port (111) and a avoiding position for avoiding the sandblasting port (111); a ball seat (30), the ball seat (30) being arranged inside the sliding sleeve (20) and moving together with the sliding sleeve (20), the ball seat (30) having a connecting flow channel (31), both ends of the connecting flow channel (31) being connected to the inside of the housing assembly (10), the inner side wall of the connecting flow channel (31) having a hardened layer formed by boronizing treatment, and at least a portion of the housing assembly (10) having a carburized layer formed by carburizing treatment; A soluble fracturing ball (40) is introduced into the shell component (10) from a liquid inlet of the shell component (10) and abuts against an inner side wall of the communication flow channel (31).

2. The horizontal well staged fracturing device according to claim 1, characterized in that: The thickness of the hardened layer is between 0.15 mm and 0.5 mm; and / or The hardness of the hardened layer is HV 0.1 1200 to HV 0.1 between 1400 and / or The strength of the hardened layer is between 34KN and 36KN; and / or The hardness of the carburized layer is above HRC65; and / or The thickness of the carburized layer is between 1.2 mm and 1.5 mm.

3. The horizontal well staged fracturing device according to claim 1, characterized in that: The ball seat (30) is made of QT500-7 ductile iron, and / or At least a portion of the housing component (10) is made of 20CrMnTi.

4. The horizontal well staged fracturing device according to claim 1, characterized in that: The fracturing module also includes: at least one starting shear pin (50), the starting shear pin (50) being arranged between the housing component (10) and the sliding sleeve (20), and two ends of the starting shear pin (50) being respectively connected to the housing component (10) and the sliding sleeve (20); When the soluble fracturing ball (40) is not dissolved, the soluble fracturing ball (40) separates the connecting flow channel (31) into two sections that are not connected to each other; When the starting shear pin (50) breaks, the sliding sleeve (20) drives the ball seat (30) and the soluble fracturing ball (40) to switch from the blocking position to the avoidance position.

5. The horizontal well staged fracturing device according to claim 1, characterized in that: The fracturing module also includes: A check ring (60), wherein the check ring (60) is made of an elastic material, and the check ring (60) is sleeved on the circumferential outer wall of the sliding sleeve (20). The inner wall of the housing assembly (10) has a locking groove (112) that cooperates with the check ring (60). When the sliding sleeve (20) moves to the avoidance position, the check ring (60) cooperates with the locking groove (112) to limit the sliding sleeve (20).

6. The horizontal well staged fracturing device according to claim 1, characterized in that: The housing assembly (10) comprises: A main body (11), the circumferential side wall of the main body (11) having at least one sandblasting port (111), and the sliding sleeve (20) being movably arranged inside the main body (11); A connecting joint (12), wherein there are two connecting joints (12), and one connecting joint (12) is provided at the liquid inlet of the main body (11) and the liquid outlet of the main body (11), respectively; one of the connecting joint (12) at the liquid outlet of the main body (11) and the sliding sleeve (20) has at least one anti-rotation protrusion, and the other has at least one anti-rotation groove; when the sliding sleeve (20) is located at the avoidance position, the anti-rotation protrusion cooperates with the anti-rotation groove to prevent the sliding sleeve (20) from rotating relative to the housing assembly (10).

7. The horizontal well staged fracturing device according to any one of claims 1 to 6, characterized in that: When the fracturing module is multi-section, the multiple sections of the fracturing module are connected in sequence, and the diameter of the soluble fracturing ball (40) of the fracturing module located downstream of two adjacent sections of the fracturing module is smaller than the diameter of the soluble fracturing ball (40) of the fracturing module located upstream.

8. The horizontal well staged fracturing device according to any one of claims 1 to 6, characterized in that: The connecting flow channel (31) comprises a guide section (311) and a main flow section (312) connected in sequence, the guide section (311) is located upstream of the main flow section (312), the diameter of the guide section (311) is larger than the diameter of the main flow section (312), and the soluble fracturing ball (40) is located at the connection between the guide section (311) and the main flow section (312).

9. The horizontal well staged fracturing device according to claim 8, characterized in that: When the fracturing module has multiple sections, the diameters of the connecting flow channels (31) of different fracturing modules are different. When the diameter of the main flow section (312) of one of the fracturing modules is less than or equal to 60 mm, the diameter of the main flow section (312) of the fracturing module located upstream thereof is increased by 3 mm; and / or When the diameter of the main flow section (312) of one of the fracturing modules is greater than 60 mm and less than or equal to 78 mm, the diameter of the main flow section (312) of the fracturing module located upstream thereof is increased by 3.5 mm; and / or When the diameter of the main flow section (312) of one of the fracturing modules is greater than 78 mm, the diameter of the main flow section (312) of the fracturing module located upstream thereof is increased by 4 mm.

10. The horizontal well staged fracturing device according to claim 8, characterized in that: When the diameter of the main flow section (312) is less than or equal to a preset value, The communicating flow channel (31) further comprises a flow leakage section (313), the flow leakage section (313) being connected to an end of the main flow section (312) away from the flow guide section (311), the diameter of the flow leakage section (313) being greater than the diameter of the main flow section (312), and the diameter of the flow leakage section (313) gradually increasing in a direction away from the main flow section (312); The guide section (311) comprises a first guide portion (3111) and a second guide portion (3112) connected in sequence, wherein one end of the second guide portion (3112) away from the first guide portion (3111) is connected to the main flow section (312), the diameter of the first guide portion (3111) is greater than the diameter of the second guide portion (3112), and the diameter of the first guide portion (3111) gradually decreases in a direction approaching the second guide portion (3112).

11. The horizontal well staged fracturing device according to claim 10, characterized in that: The connection between the second flow guide portion (3112) and the main flow section (312) has a step surface (314), the soluble fracturing ball (40) abuts against the step surface (314), and at least a portion of the soluble fracturing ball (40) is located in the main flow section (312), and at least another portion of the soluble fracturing ball (40) is located in the second flow guide portion (3112).

12. The horizontal well staged fracturing device according to claim 10, characterized in that: The second flow guide portion (3112) has the same diameter at all locations; and / or The main flow section (312) has the same diameter at all locations.

13. The horizontal well staged fracturing device according to claim 10, characterized in that: The angle between the first flow guiding portion (3111) and the second flow guiding portion (3112) is greater than or equal to 25° and less than or equal to 30°; and / or The angle between the leakage section (313) and the main flow section (312) is greater than or equal to 35° and less than or equal to 45°; and / or The inner diameter of the main flow section (312) is A mm, the inner diameter of the second flow guide portion (3112) is B, and B=(A+4.5) mm; and / or The inner diameter of the main flow section (312) is A mm, the length of the second guide portion (3112) is C, and C=78-tan63°*(86.5-A) / 2, and the length of the first guide portion (3111) is D, and D=tan63°*(86.5-A) / 2.

14. The horizontal well staged fracturing device according to claim 8, characterized in that: When the diameter of the main flow section (312) is greater than a preset value, the diameter of the guide section (311) gradually decreases in a direction approaching the main flow section (312), and the angle between the guide section (311) and the main flow section (312) is 45°.

15. A surface treatment method for a ball seat, characterized in that: The ball seat of the fracturing module in the horizontal well staged fracturing device according to any one of claims 1 to 14 uses the surface treatment method of the ball seat to form a hardened layer, and the surface treatment method of the ball seat comprises: The ball seat (30) is placed in a heat-resistant sealed can, wherein the heat-resistant sealed can contains boron powder and an active agent, and the boron powder and the active agent cover the ball seat (30); The heat-resistant sealed can is placed in a high-temperature heating furnace and heated. The ball seat (30) reacts with the boron powder under the action of the activator, and the surface of the ball seat (30) is subjected to boronizing treatment to form the hardened layer.

16. The surface treatment method of a ball seat according to claim 15, characterized in that: During the process of placing the ball seat (30) in the heat-resistant sealed can, the sealing cover of the heat-resistant sealed can is opened, the boron powder of a preset thickness is spread in the heat-resistant sealed can, the ball seat (30) is placed at the center of the boron powder in the heat-resistant sealed can, the boron powder is evenly spread around the periphery of the ball seat (30) and compacted, the boron powder is evenly spread above the ball seat (30) and compacted, and the sealing cover is closed.

17. The surface treatment method of a ball seat according to claim 15, characterized in that: Before the surface of the ball seat (30) is subjected to the boronizing treatment, the ball seat (30) is subjected to sandblasting treatment; and / or After the surface of the ball seat (30) is subjected to the boronizing treatment, the ball seat (30) is subjected to sandblasting treatment.

18. The surface treatment method of a ball seat according to claim 15, characterized in that: After the heat-resistant sealed can is placed in the high-temperature heating furnace, the pressure in the high-temperature heating furnace is evacuated to 0 Pa and a deoxygenation operation is performed, the high-temperature heating furnace is dehumidified and argon gas is injected into the high-temperature heating furnace until the pressure in the high-temperature heating furnace reaches 1 Pa, and the heat-resistant sealed can is heated by the high-temperature heating furnace to cause the ball seat (30) to react with the boron powder.

19. The surface treatment method of a ball seat according to claim 18, characterized in that: When the heat-resistant sealed can is heated by the high-temperature heating furnace, the heat-resistant sealed can is first heated to 500° C. and kept warm for 2 hours, then the heat-resistant sealed can is preheated to a certain temperature, and then heated to 960° C. and kept warm for 12 hours, the ball seat (30) is surface-coated, and finally naturally cooled to room temperature.

20. A surface treatment method for a shell component, characterized in that: The shell component of the fracturing module in the horizontal well staged fracturing device according to any one of claims 1 to 14 uses the surface treatment method of the shell component to form a carburized layer, and the surface treatment method of the shell component comprises: The shell component (10) is formed with a sandblasting port (111) by wire cutting, at least a portion of the shell component (10) is carburized to form a carburized layer, the portion cut off during the wire cutting process is placed into the sandblasting port (111), the outer surface of the connection between the sandblasting port (111) and the cut off portion is spot welded, and the inner wall surface of the shell component (10) is ground.

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