Hydraulic spray gun for fracturing

Abstract

The utility model provides a hydraulic spray gun for fracturing, and belongs to the technical field of underground mining equipment for promoting yield by forming cracks or cracks. The hydraulic spray gun for fracturing comprises a spray gun body, the spray gun body is provided with a spraying structure used for spraying fracturing fluid into a stratum, a sliding sleeve is arranged in the spray gun body, the end of the spray gun body is connected with a connector in a sealed mode, and a stopping step is arranged on the inner wall of one of the connector and the spray gun body. A shear pin seat is clamped between the other end face of the sliding sleeve and the stopping step, the shear pin seat is located on the inner side of the sealing connection portion of the spray gun body and the connector, a shear pin is installed on the shear pin seat, a ball seat is installed at the end of the sliding sleeve, an inner conical face used for being in contact sealing fit with a ball sealer is arranged on the ball seat, and a positioning groove is formed in the peripheral face of the ball seat. And the end part of the shear pin is inserted into the positioning groove. According to the utility model, after the shear pin is sheared off, fracturing fluid cannot leak to the outside through the position of the shear pin, and the jet fracturing effect of the jet structure is not influenced.

Description

Technical Field

[0001] This utility model relates to a hydraulic spray gun for fracturing, belonging to the technical field of downhole mining equipment that promotes production by forming fissures or cracks. Background Technology

[0002] Hydraulic jet fracturing technology is an integrated oil and gas reservoir stimulation technology that combines perforation, fracturing, and isolation. It eliminates the need for packers and is an effective method for fracturing and increasing production in low-permeability oil and gas reservoirs, applicable to various well types. The core of this technology is the hydraulic jet gun, which is currently mainly divided into single-stage and multi-stage hydraulic jet guns. Single-stage hydraulic jet guns do not have sliding sleeves; the nozzle is installed on the gun body, and it can only hydraulically fracture one layer. Multi-stage hydraulic jet guns have multiple sliding sleeves inside, allowing for fracturing and stimulation of multi-layered oil and gas reservoirs by sequentially dropping balls.

[0003] Chinese utility model patent CN204457712U discloses a sliding sleeve type hydraulic jet ejector. The sliding sleeve type hydraulic jet ejector includes an ejector body, a sliding sleeve seat, and a sliding sleeve. The ejector body and the sliding sleeve seat are integrally connected. The sliding sleeve is set in the ejector body and fixed to the ejector body by shear pins. The sliding sleeve is a thin-walled cylindrical shape with an inner conical surface at the upper end. After a steel ball is inserted, the steel ball falls onto the inner conical surface at the upper end of the sliding sleeve. As the wellhead is continuously pressurized, the shear pins are sheared, and the steel ball pushes the sliding sleeve downward, exposing the nozzle installed on the ejector body. The fracturing fluid can then be ejected through the nozzle for hydraulic jet fracturing.

[0004] The shear pins (hereinafter referred to as shear pins) used to fix the sliding sleeve are usually threaded onto the injector body (i.e., the spray gun body). The end of the shear pin is inserted into the positioning groove on the outer circumference of the sliding sleeve to position the sliding sleeve. After the shear pin is cut and the sliding sleeve moves downward, because the shear pin and the spray gun body are connected by ordinary threads, there is a gap at the threaded engagement. The fracturing fluid will leak outward through this gap. Moreover, because the connection between the shear pin and the spray gun body is relatively weak, the shear pin is easy to detach from the spray gun body under the impact of the fracturing fluid, resulting in a large hole in the spray gun body. In this way, the fracturing fluid will leak outward from the threaded engagement between the shear pin and the spray gun body, and even from the hole after the shear pin is washed away, in addition to being sprayed out of the nozzle. This affects the fracturing effect of the fracturing fluid sprayed from the nozzle, causing the fracturing operation to fail to achieve the expected purpose. Utility Model Content

[0005] The purpose of this invention is to provide a hydraulic spray gun for fracturing, in order to solve the problem in the prior art that fracturing fluid leaks outward from the threaded joint between the shear pin and the spray gun body, or even from the holes after the shear pin is washed away, which affects the spraying fracturing effect of the nozzle and prevents the fracturing operation from achieving the expected purpose.

[0006] To achieve the above objectives, the hydraulic fracturing gun of this utility model adopts the following technical solution:

[0007] A hydraulic fracturing gun includes a gun body with a spraying structure for injecting fracturing fluid into the formation. A sliding sleeve is provided within the gun body. A connector is sealed to the end of the gun body. A stop step is provided on the inner wall of one of the connector and the gun body. A shear pin seat is clamped between the end face of the other connector and the stop step. The shear pin seat is located inside the sealed connection between the gun body and the connector. A shear pin is installed on the shear pin seat. A ball seat is installed at the end of the sliding sleeve. The ball seat has an inner conical surface for contacting and sealing with a plugging ball. A positioning groove is provided on the outer circumferential surface of the ball seat, and the end of the shear pin is inserted into the positioning groove.

[0008] The beneficial effects of the above technical solution are as follows: This utility model is an improved invention. Specifically, a connector is sealed at the end of the spray gun body. A stop step is provided on the inner wall of one of the connector and the spray gun body, and a shear pin seat is clamped between the end face of the other connector and the stop step, facilitating the installation of the shear pin seat. The shear pin seat is located inside the sealed connection between the spray gun body and the connector. Shear pins are installed on the shear pin seat, and a ball seat is installed at the end of the sliding sleeve. The ball seat has an inner conical surface for contacting and sealing with the sealing ball. A positioning groove is provided on the outer circumference of the ball seat. The end of the shear pin is inserted into the positioning groove, which can position the ball seat and thus position the sliding sleeve connected to the ball seat. When the sealing ball is inserted for pressurization, the sealing ball sits on the inner conical surface of the ball seat. When the pressure reaches a certain value, the shear pin is sheared, and the ball seat and the sliding sleeve can move downward to open the spray structure, thereby enabling the spray structure to perform spray fracturing operations. Because the shear pin seat is located inside the sealed connection between the spray gun body and the joint, the fracturing fluid can no longer leak to the outside through the shear pin, thus ensuring the spray fracturing effect of the spray structure and ensuring that the fracturing operation can achieve the expected purpose.

[0009] Furthermore, the ball seat and the sliding sleeve are respectively provided with a stop step, the end face of the ball seat and the stop step on the sliding sleeve are in a stop fit in the axial direction of the sliding sleeve, and the end face of the sliding sleeve and the stop step on the ball seat are in a stop fit in the axial direction of the sliding sleeve.

[0010] Furthermore, the end of the ball seat is provided with a tapered hole that connects to the inner hole of the sliding sleeve. The end face of the ball seat that mutually blocks and cooperates with the sliding sleeve has the same area as the abutting step on the ball seat.

[0011] Furthermore, the ball seat and the sliding sleeve are connected by a threaded structure.

[0012] Furthermore, a sealing ring is provided between the ball seat and the sliding sleeve. One of the ball seat and the sliding sleeve has an external thread, and the other has an internal thread. The sealing ring is fitted at the root of the external thread.

[0013] Furthermore, the spray gun body is provided with a radially penetrating mounting hole, and the spraying structure is a nozzle assembled in the mounting hole.

[0014] Furthermore, the mounting hole is a tapered hole with an inner diameter that gradually decreases from the inside to the outside, and the nozzle is provided with an outer conical surface that matches the tapered hole.

[0015] Furthermore, the nozzles are arranged in at least two concentric rings along the axial direction of the spray gun body, and each ring includes at least two nozzles arranged circumferentially.

[0016] Furthermore, the connector is defined as an upper connector connected to the upper end of the spray gun body, the ball seat is installed on the upper end of the sliding sleeve, the nozzles of each ring are arranged vertically, the lower end of the spray gun body is connected to a sitting connector, and the inner wall of the sitting connector is provided with a stop step for cooperating with the lower end face of the sliding sleeve when the sliding sleeve moves downward. The distance from the upper end face of the ball seat to the bottommost ring of nozzles is less than the distance from the lower end face of the sliding sleeve to the stop step.

[0017] Furthermore, the connector is connected to the spray gun body via a tapered thread seal. Attached Figure Description

[0018] Figure 1 This is a structural diagram of Embodiment 1 of the hydraulic spray gun for fracturing according to this utility model;

[0019] Figure 2 for Figure 1 A magnified view of a portion of the image;

[0020] Figure 3 This is a structural diagram of Example 2 of the hydraulic spray gun for fracturing according to this utility model.

[0021] In the diagram: 1. Upper connector; 1-1. Connector stop step; 2. Shear pin seat; 3. Shear pin; 4. Sealing ball; 5. Ball seat; 5-1. Upper inner cone surface; 5-2. Lower inner cone surface; 5-3. Ball seat abutment step; 6. Spray gun body; 6-1. Body stop step; 7. Nozzle; 8. Sliding sleeve; 8-1. Sliding sleeve abutment step; 9. Sealing connector; 9-1. Stop step; 10. Upper sealing ring; 11. Lower sealing ring; 12. Sealing ring. Detailed Implementation

[0022] To address the technical problems existing in the prior art, the basic concept of this utility model is to set up a shearing nail seat specifically for installing shearing nails, and to clamp the shearing nail seat between the joint and the spray gun body. The shearing nail seat is located inside the sealed connection between the spray gun body and the joint. In this way, after the shearing nail is cut, the fracturing fluid cannot leak to the outside through the location of the shearing nail, ensuring that the spray fracturing effect of the spray structure is not affected.

[0023] The features and performance of this utility model will be further described in detail below with reference to the embodiments.

[0024] The implementation method of the hydraulic spray gun for medium-pressure fracturing in this utility model is as follows:

[0025] like Figure 1 As shown, the hydraulic fracturing gun includes a gun body 6, which is equipped with a spraying structure for spraying fracturing fluid into the formation. The axis of the gun body 6 is defined to extend in the vertical direction, and a connector, namely the upper connector 1, is sealed and connected at the upper end of the gun body 6 (if the axis of the gun body 6 is defined to extend in the horizontal direction, the upper connector 1 is sealed and connected at the left end of the gun body 6).

[0026] Specifically, the upper connector 1 has an internal cavity that runs vertically through it. As in Example 1, for instance... Figure 1 and Figure 2 As shown, the upper connector 1 has internal threads at both its upper and lower ends, and both internal threads are tapered threads. The upper internal thread is used to connect with the fracturing tubing, and the corresponding fracturing tubing has external threads, which are also tapered threads. The tapered threads naturally create a seal at the connection. The lower internal thread of the upper connector 1 is used to connect with the spray gun body 6. The upper end of the spray gun body 6 has external threads, which are also tapered threads. The tapered threads naturally create a seal at the connection between the upper connector 1 and the spray gun body 6.

[0027] like Figure 3 As shown, in embodiment 2, the lower end of the upper connector 1 can be configured with an external thread, and the upper end of the corresponding spray gun body 6 is configured with an internal thread. Both the internal and external threads are tapered threads, which can also achieve a seal at the connection between the upper connector 1 and the spray gun body 6. Similarly, the upper end of the upper connector 1 can also be configured with an external thread, and the corresponding fracturing string is configured with an internal thread. To ensure a seal, both the internal and external threads are still tapered threads. Of course, in other embodiments, adhesive can be applied or raw rubber tape can be wrapped around the threaded joint to enhance the sealing effect. In other embodiments, the tapered thread can be completely replaced with a cylindrical thread. In this case, to ensure the connection seal, a rubber ring can be fitted at the root of the external thread. When the internal and external threads are connected in place, the rubber ring is compressed to achieve a seal.

[0028] like Figure 1 and Figure 2 As shown, an annular protrusion is provided on the inner wall of the upper connector 1. The lower end face of the annular protrusion forms a connector stop step 1-1. A shear pin seat 2 is clamped between the connector stop step 1-1 and the upper end face of the spray gun body 6. Shear pins 3 are installed on the shear pin seat 2. The shear pin seat 2 is located inside the sealing connection between the spray gun body 6 and the upper connector 1. Figure 2The shear pin seat 2 shown is covered by the upper connector 1. Even if the shear pin 3 is cut off during use, the fracturing fluid cannot leak from the position of the shear pin 3 to the outside, thus ensuring the fracturing effect of the spray structure and ensuring that the fracturing operation can achieve the expected purpose.

[0029] In Example 2, as Figure 3 As shown, a body stop step 6-1 is provided on the inner wall of the spray gun body 6. The shear pin seat 2 is clamped between the body stop step 6-1 and the lower end face of the upper connector 1. Similarly, the shear pin seat 2 is located inside the sealing connection part of the spray gun body 6 and the upper connector 1. However, the shear pin seat 2 is covered by the spray gun body 6, so the fracturing fluid cannot leak to the outside from the position of the shear pin 3.

[0030] like Figure 1 and Figure 2 As shown, a sliding sleeve 8 is provided in the inner hole of the spray gun body 6. The outer diameter of the sliding sleeve 8 is adapted to the inner diameter of the spray gun body 6, so that the sliding sleeve 8 can move up and down along the spray gun body 6. The sliding sleeve 8 is a thin-walled cylindrical structure, and a ball seat 5 is installed at its upper end. An upper inner conical surface 5-1 and a lower inner conical surface 5-2 are formed on the inner wall of the ball seat 5. The upper inner conical surface 5-1 is used to contact and seal with the sealing ball 4 to block the channel for fracturing fluid flow.

[0031] In this embodiment, the ball seat 5 and the sliding sleeve 8 are connected by a threaded structure, which facilitates their installation and disassembly. To ensure a tight seal, a sealing ring 12 is provided between the ball seat 5 and the sliding sleeve 8. Specifically, the ball seat 5 has an external thread, and the sliding sleeve 8 has an internal thread. The sealing ring 12 is fitted onto the root of the external thread, and is compressed to achieve a seal when the ball seat 5 and the sliding sleeve 8 are in place. Of course, in other embodiments, the sliding sleeve 8 may also have an external thread, while the ball seat 5 may have an internal thread, with the sealing ring 12 still fitted onto the root of the external thread. In other embodiments, the ball seat 5 and the sliding sleeve 8 may not be connected by a threaded structure, but may be directly welded together.

[0032] It is worth noting that during the manufacturing process of the hydraulic spray gun for fracturing, if the conventional setup requires machining a tapered surface directly on the top of the inner wall of the sliding sleeve 8, and the tapered surface of the sliding sleeve 8 to match the plugging ball 4, then multiple sliding sleeves 8 with different inner diameters need to be manufactured so that the tapered surface at the top of each sliding sleeve 8 can fit with plugging balls 4 of different diameters to meet the needs of multi-stage fracturing. If the outer diameters of all sliding sleeves 8 are the same, the wall thicknesses will be different, resulting in material waste; if the wall thicknesses of all sliding sleeves 8 are the same, the outer diameters will be different, which leads to changes in the specifications of the spray gun body 6 and the upper connector 1 that mate with the sliding sleeves 8. This requires manufacturing various specifications of sliding sleeves 8, spray gun body 6, and upper connector 1, making the manufacturing process cumbersome and significantly increasing the manufacturing cost. In comparison, this utility model uses an independent ball seat 5 to cooperate with the sealing ball 4. Only ball seats 5 with different inner hole sizes need to be processed to match sealing balls 4 of different sizes. The sliding sleeve 8, spray gun body 6 and upper connector 1 can adopt the same specifications and models. Since the ball seat 5 is relatively small, it is not only convenient to process, but also can greatly save processing materials.

[0033] A positioning groove is provided on the outer circumferential surface of the ball seat 5, and a threaded through hole is provided on the shear pin seat 2 along the radial direction. The shear pin 3 is threaded into the threaded through hole, and the end of the shear pin 3 is inserted into the positioning groove to restrict the movement of the ball seat 5. Before the shear pin 3 reaches the set shearing force, the ball seat 5 always maintains a fixed relative position with the shear pin seat 2.

[0034] In this embodiment, the outer periphery of the ball seat 5 is stepped, including an upper large-diameter section and a lower small-diameter section. A ball seat abutment step 5-3 is formed between the large-diameter section and the small-diameter section. The positioning groove for inserting the end of the shear pin 3 is provided on the large-diameter section, and the outer surface of the small-diameter section is provided with external threads. The upper end of the sliding sleeve 8 is provided with an enlarged threaded hole and a sliding sleeve abutment step 8-1 connected to the threaded hole. When the sliding sleeve 8 is connected to the ball seat 5, the lower end face of the ball seat 5 and the sliding sleeve abutment step 8-1 are engaged in an axial stop fit in the sliding sleeve, and the upper end face of the sliding sleeve 8 and the ball seat abutment step 5-3 are engaged in an axial stop fit in the sliding sleeve. In this way, when the ball seat 5 is subjected to a downward force, the force can be better transmitted to the sliding sleeve 8 through the ball seat abutment step 5-3 and the lower end face of the ball seat 5, thereby driving the sliding sleeve 8 to move.

[0035] Due to the presence of the lower inner conical surface 5-2, a conical hole is formed at the lower end of the ball seat 5. This conical hole connects with the inner hole of the sliding sleeve 8, making the lower end face of the ball seat 5, which is mutually blocking and fits, the same as the area of ​​the sliding sleeve abutting the step 8-1. At the same time, the upper end face of the sliding sleeve 8, which is mutually blocking and fits, the same as the area of ​​the ball seat abutting the step 5-3. That is, the outer diameter of the sliding sleeve 8 is equal to the outer diameter of the ball seat 5. This achieves optimal force transmission and a relatively compact structure. The inner diameter of the sliding sleeve 8 will not be too large, and it also ensures that after the shear pin 3 is cut, the ball seat 5 and the sliding sleeve 8 can smoothly descend together. Of course, in other embodiments, the lower end of the ball seat 5 may not be provided with a tapered hole, that is, the lower inner tapered surface 5-2 may not be provided. Except for the upper inner tapered surface 5-1 that contacts and seals with the sealing ball 4, the inner wall of the ball seat 5 is an inner cylindrical surface. Compared with embodiment 1, if the area of ​​the stop fit is the same, the wall thickness of the sliding sleeve 8 needs to be increased so that the inner diameter of the sliding sleeve 8 is the same as the inner diameter of the inner cylindrical surface.

[0036] like Figure 1 As shown, the spray gun body 6 has a radially through mounting hole. In this embodiment, the spray structure is a nozzle 7 assembled in the mounting hole. Using a separate nozzle 7 as the spray structure makes it easier to ensure the spray fracturing effect. In other embodiments, only the spray hole can be provided on the spray gun body 6 as the spray structure, without installing a separate nozzle.

[0037] Furthermore, the aforementioned mounting hole is a tapered hole with an inner diameter that gradually decreases from the inside to the outside. The nozzle 7 has an outer conical surface that matches the tapered hole. During installation, the nozzle 7 is pressed into the mounting hole from one side of the inner hole of the spray gun body 6. When the fracturing fluid is ejected from the spray gun body 6 at high speed, the connection between the nozzle 7 and the mounting hole will be tighter under the strong extrusion force. To further improve the sealing performance and prevent the fracturing fluid from leaking from the connection between the nozzle 7 and the spray gun body 6, a sealing ring can be fitted onto the outside of the nozzle 7. In other embodiments, the mounting hole can be a threaded hole of equal diameter. The nozzle 7 is threaded into the mounting hole. To prevent the nozzle 7 from coming out, a step can be provided at the end of the mounting hole to stop and cooperate with the end face of the nozzle 7. Of course, in other embodiments, the nozzle 7 can also be directly welded and fixed in the mounting hole.

[0038] Furthermore, the nozzle 7 is along the axial direction of the spray gun body 6 ( Figure 1 The nozzles 7 are arranged in at least two rings (vertically and vertically) at intervals, and each ring includes at least two nozzles 7 arranged circumferentially. This allows for simultaneous jet fracturing at multiple locations in the formation, improving the effectiveness of jet fracturing. Specifically, in this embodiment, there are three rings of nozzles 7, with two nozzles in each ring. In other embodiments, there may be only two rings of nozzles 7, or even four or more rings, with more than three nozzles 7 in each ring, and the nozzles 7 in each ring are evenly spaced.

[0039] like Figure 1 As shown, an upper sealing ring 10 is installed on the upper outer circumferential surface of the sliding sleeve 8, and a lower sealing ring 11 is installed on the lower outer circumferential surface. The upper sealing ring 10 and the lower sealing ring 11 are provided in two layers. Before the shear pin 3 is cut, the upper sealing ring 10 and the lower sealing ring 11 are in sealed contact with the inner wall of the spray gun body 6. The upper sealing ring 10 is located above the uppermost ring of nozzles 7, and the lower sealing ring 11 is located below the lowermost ring of nozzles 7. This can effectively prevent fracturing fluid from leaking from the connection between different components, ensuring the efficiency and safety of fracturing operations.

[0040] The lower end of the spray gun body 6 is connected to a landing connector 9. The inner hole of the landing connector 9 has a stepped structure, which includes an upper inner hole, a middle inner hole and a lower inner hole with gradually decreasing inner diameter from top to bottom. The upper inner hole is provided with an internal thread for sealing connection with the lower end of the spray gun body 6. The outer surface of the lower end of the landing connector 9 is provided with an external thread for sealing connection with the fracturing tubing.

[0041] The outer diameter of the sliding sleeve 8 is matched with the inner diameter of the middle inner hole, allowing the sliding sleeve 8 to descend after the shear pin 3 is cut, entering the middle inner hole of the settling connector 9 through the inner hole of the spray gun body 6. The outer diameter of the sliding sleeve 8 is larger than the inner diameter of the lower inner hole. When the sliding sleeve 8 moves downward, its lower end face eventually abuts against the stop step 9-1 between the middle inner hole and the lower inner hole, thus limiting the downward movement of the sliding sleeve 8 to its extreme position. When the shear pin 3 is not cut (i.e., Figure 1 (As shown in the state) The distance from the upper end face of the ball seat 5 to the bottommost ring of nozzles 7 is less than the distance from the lower end face of the sliding sleeve 8 to the stop step 9-1, so that when the lower end face of the sliding sleeve 8 finally touches the stop step 9-1, all the nozzles 7 can be exposed, that is, the sliding sleeve 8 and the ball seat 5 do not block the nozzles 7.

[0042] Furthermore, the distance between the upper sealing ring 10 and the lower sealing ring 11 is greater than the distance from the lower end face of the spray gun body 6 to the stop step 9-1, so that during the downward movement of the sliding sleeve 8, the upper sealing ring 10 always closely contacts the inner wall of the spray gun body 6. After the sliding sleeve 8 enters the settling joint 9, the lower sealing ring 11 closely contacts the inner wall of the middle hole of the settling joint 9, thereby achieving effective sealing of the threaded connection between the spray gun body 6 and the settling joint 9 by the sliding sleeve 8.

[0043] The working principle of this invention is as follows: During single-stage fracturing of a formation, the fracturing hydraulic nozzle is connected to the tubing and lowered into the target location in the well. Then, a plugging ball 4 is dropped at the wellhead, landing on the upper inner conical surface of the ball seat 5. Continuous pressure is applied at the wellhead, causing the plugging ball 4 to push the ball seat 5 and shear the shear pins 3. The upper inner conical surface provides a uniform force-bearing surface for the plugging ball 4, ensuring a good seal between the plugging ball 4 and the ball seat 5. This ensures a stable increase in the pressure difference between the upper and lower sides of the plugging ball 4 during pressure application, improving the pressure application effect. The plugging ball 4 then pushes the ball seat 5 and the sliding sleeve 8 downwards along the inner wall of the nozzle body 6 until the lower end face of the sliding sleeve 8 abuts against the stop step 9-1 of the landing joint 9. The sliding sleeve 8 and the ball seat 5 do not obstruct the nozzle 7; the nozzle 7 is fully open, and the fracturing fluid is delivered to the rock formation through the nozzle 7, completing the fracturing operation. In the above process, by clamping the shear pin seat 2 between the upper connector 1 and the spray gun body 6, and by making a threaded seal connection between the upper connector 1 and the spray gun body 6, the fracturing fluid can be prevented from leaking to the outside of the spray gun through the shear pin 3, thus ensuring stable and efficient fracturing operations.

[0044] It should be noted that when performing single-stage fracturing on a formation, a single-stage spray gun without a ball seat and sliding sleeve can be directly lowered. In this case, all the nozzles on the spray gun body are open, and fracturing fluid can be directly pumped in for fracturing operations without the need to drop a ball. Of course, this single-stage spray gun can be manufactured separately, or it can be formed by removing the sliding sleeve and ball seat from the hydraulic spray gun for fracturing of this utility model.

[0045] When multi-stage fracturing operations are required, multiple hydraulic fracturing guns are first connected to form a fracturing string (the lowest gun in the fracturing string can be the hydraulic fracturing gun of this invention, or a single-stage gun without a ball seat and sliding sleeve; the single-stage gun can be manufactured separately, or it can be formed by removing the sliding sleeve and ball seat from the hydraulic fracturing gun of this invention). A set of sealing balls 4 with an ordered diameter gradient is prepared, and the sealing balls 4 are adapted to the ball seats 5 of the multiple hydraulic fracturing guns. Then, the string is smoothly and slowly lowered to the designed position. If the lowest gun is a single-stage gun without a ball seat and sliding sleeve, fracturing fluid can be directly pumped in for the lowest stage of fracturing. If the lowest gun has a ball seat and sliding sleeve, the smallest diameter sealing ball 4 is first dropped from the wellhead. The sealing ball 4 pushes the ball seat 5 and sliding sleeve 8 of the lowest gun downwards, and the fracturing fluid is ejected from the nozzle 7, completing the first stage of fracturing. Next, a larger diameter plugging ball 4 is dropped into the tubing string. This effectively plugs the tubing from the previous stage and also causes the nozzle 7 of the hydraulic spray gun to open, thus completing a new stage of fracturing. By gradually dropping plugging balls 4 with increasing diameters, fracturing operations are carried out on each designed well section in sequence, thereby completing multi-stage segmented fracturing construction.

[0046] In other embodiments of hydraulic fracturing guns: the connector and the gun body can also be directly welded together. In this case, the shear pin seat is located inside the welded part between the connector and the gun body, and the welded part is a full circumference to ensure that the fracturing fluid does not leak.

[0047] In other embodiments of hydraulic spray guns for fracturing: the spray gun body and the landing joint can be connected as one piece, that is, the landing joint is no longer assembled separately. In this case, the stop step that cooperates with the lower end face stop of the sliding sleeve is integrally machined on the inner wall of the spray gun body.

[0048] In other embodiments of hydraulic spray guns used for fracturing: the nozzle may be arranged in only one ring on the spray gun body.

[0049] In other embodiments of hydraulic spray guns for fracturing: a ball seat abutment step may be provided only on the ball seat, while a sliding sleeve abutment step may not be provided on the sliding sleeve. In this case, only the ball seat abutment step and the end face of the sliding sleeve are in a stop-fitting relationship. In other embodiments, a sliding sleeve abutment step may be provided only on the sliding sleeve, while a ball seat abutment step may not be provided on the ball seat. In this case, only the sliding sleeve abutment step and the end face of the ball seat are in a stop-fitting relationship.

[0050] In other embodiments of hydraulic spray guns used for fracturing: when the ball seat and the sliding sleeve are fixed by welding, the abutment step may not be provided on either the ball seat or the sliding sleeve.

[0051] In other embodiments of hydraulic spray guns used for fracturing: the shear pins may not be installed by a threaded connection. The outer circumferential surface of the shear pins is smooth. The shear pins are inserted into the shear pin holder. Since the shear pin holder is covered by the upper connector or the spray gun body, the covered part can block the end of the shear pin and limit the displacement of the shear pin.

[0052] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. The patent protection scope of the present utility model shall be determined by the claims. Similarly, any equivalent structural changes made based on the description and drawings of the present utility model shall also be included within the protection scope of the present utility model.

Claims

1. A hydraulic fracturing nozzle, comprising a nozzle body, wherein the nozzle body is provided with a jetting structure for injecting fracturing fluid into the formation, and a sliding sleeve is provided within the nozzle body, characterized in that, The spray gun body has a sealing connection at the end of a connector. A stop step is provided on the inner wall of one of the connectors and the spray gun body. A shear pin seat is clamped between the end face of the other connector and the stop step. The shear pin seat is located inside the sealing connection between the spray gun body and the connector. Shear pins are installed on the shear pin seat. A ball seat is installed at the end of the sliding sleeve. The ball seat has an inner conical surface for contacting and sealing with the sealing ball. A positioning groove is provided on the outer circumferential surface of the ball seat. The end of the shear pin is inserted into the positioning groove.

2. The hydraulic fracturing gun according to claim 1, characterized in that, The ball seat and the sliding sleeve are respectively provided with a stop step. The end face of the ball seat and the stop step on the sliding sleeve are in a stop fit in the axial direction of the sliding sleeve. The end face of the sliding sleeve and the stop step on the ball seat are in a stop fit in the axial direction of the sliding sleeve.

3. The hydraulic fracturing gun according to claim 2, characterized in that, The ball seat end is provided with a tapered hole that connects to the inner hole of the sliding sleeve. The end face of the ball seat and the sliding sleeve have the same area as the abutting step.

4. The hydraulic fracturing gun according to any one of claims 1 to 3, characterized in that, The ball seat and the sliding sleeve are connected by a threaded structure.

5. The hydraulic fracturing gun according to claim 4, characterized in that, A sealing ring is provided between the ball seat and the sliding sleeve. One of the ball seat and the sliding sleeve has an external thread, and the other has an internal thread. The sealing ring is fitted at the root of the external thread.

6. The hydraulic fracturing gun according to any one of claims 1 to 3, characterized in that, The spray gun body has a radially through mounting hole, and the spraying structure is a nozzle assembled in the mounting hole.

7. The hydraulic fracturing gun according to claim 6, characterized in that, The mounting hole is a tapered hole with an inner diameter that gradually decreases from the inside to the outside, and the nozzle has an outer conical surface that matches the tapered hole.

8. The hydraulic fracturing gun according to claim 6, characterized in that, The nozzles are arranged in at least two rings along the axial direction of the spray gun body, and each ring includes at least two nozzles arranged circumferentially.

9. The hydraulic fracturing gun according to claim 8, characterized in that, The connector is defined as an upper connector connected to the upper end of the spray gun body. The ball seat is installed on the upper end of the sliding sleeve. The nozzles of each ring are arranged vertically. The lower end of the spray gun body is connected to a landing connector. The inner wall of the landing connector is provided with a stop step for cooperating with the lower end face of the sliding sleeve when the sliding sleeve moves downward. The distance from the upper end face of the ball seat to the bottommost ring of nozzles is less than the distance from the lower end face of the sliding sleeve to the stop step.

10. The hydraulic fracturing gun according to any one of claims 1 to 3, characterized in that, The connector and the spray gun body are connected by a tapered thread seal.

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