A gap stepless steering system and its application method

Abstract

The invention discloses a seam stepless steering system and an application method thereof, which relate to the technical field of oil and gas exploitation, and include a fracturing vehicle group, a fracturing main line and a fracturing branch line, wherein the fracturing vehicle group can transport fracturing fluid through the fracturing main line and the fracturing branch line to fracture rock formations, and the fracturing branch line can add temporary plugging balls to the fracturing fluid; the fracturing branch line includes a first plug valve, a second plug valve and a temporary plugging ball delivery device, wherein the temporary plugging ball delivery device is arranged between the first plug valve and the second plug valve; the temporary plugging ball delivery device includes a first driving device, a plurality of ball delivery devices and a five-way connecting pipe, wherein the plurality of ball delivery devices are all connected to the five-way connecting pipe, the first driving device can selectively connect the ball delivery device with the five-way connecting pipe, and can selectively deliver the temporary plugging balls in the ball delivery device to the five-way connecting pipe; the invention can accurately deliver temporary plugging balls of different sizes through corresponding design.

Description

Technical Field

[0001] The invention relates to the technical field of oil and gas exploitation, and in particular to a slot stepless steering system and an application method thereof. Background Art

[0002] The fracture diversion fracturing process is an advanced oil and gas field production enhancement technology, mainly used to improve the development efficiency of low permeability oil and gas reservoirs. This process implements fracture diversion during the fracturing process, so that the fracturing fluid can be more evenly distributed in the target formation, thereby forming more fracture networks and increasing oil and gas production. Traditional fracturing processes can often only form a single fracture, while the fracture diversion fracturing process can form multiple fractures by controlling the flow direction of the fracturing fluid, greatly improving the fracturing effect. The core of this process is to use temporary plugging technology to enable the fracturing fluid to be diverted between different fractures, thereby achieving a more uniform fracture distribution.

[0003] In the seam-turning fracturing process, the use of temporary plugging balls is a key link. However, the traditional method of adding temporary plugging balls has some obvious defects. First, the selection of temporary plugging timing is too rigid, usually relying on experience judgment and the continuation of previous designs, and lacks understanding of the actual construction effect and the opening state of the fracture. This fixed method of selecting the timing of temporary plugging often cannot be flexibly adjusted according to the actual construction situation, resulting in unsatisfactory fracturing effect. Secondly, since the number of temporary plugging balls to be used has been determined at the beginning of the design, and it is a one-time investment, the number of temporary plugging balls invested is fixed, and there may be too many or too few. If too many temporary plugging balls are invested, the pump pressure will be too high, overpressure will occur, and the pump will stop, which will directly affect subsequent construction. This method of investing a fixed number of temporary plugging balls cannot be dynamically adjusted according to the actual construction situation, which increases the construction risk.

[0004] Therefore, based on the above-mentioned defects of the prior art, it is necessary to further improve the prior art. Summary of the invention

[0005] The object of the present invention is to provide a slot stepless steering system and an application method thereof to solve the above-mentioned problems.

[0006] The present invention is achieved through the following technical solutions:

[0007] A seam stepless steering system comprises a fracturing vehicle group, a fracturing main line and a fracturing branch line, wherein the fracturing vehicle group can transport fracturing fluid through the fracturing main line and the fracturing branch line to fracture rock formations, and the fracturing branch line can add temporary plugging balls into the fracturing fluid;

[0008] The fracturing branch pipeline comprises a first plug valve, a second plug valve and a temporary plugging ball delivery device, wherein the temporary plugging ball delivery device is arranged between the first plug valve and the second plug valve;

[0009] The temporary blocking ball delivery device includes a first driving device, multiple ball delivery devices and a five-way connecting pipe, wherein the multiple ball delivery devices are connected to the five-way connecting pipe, and the first driving device can selectively connect the ball delivery device and the five-way connecting pipe, and can selectively deliver the temporary blocking ball in the ball delivery device to the five-way connecting pipe.

[0010] The present invention also relates to an application method of a slot continuously variable steering system, which is implemented by using the slot continuously variable steering system, and comprises the following steps:

[0011] Step 1: Place temporary blocking balls of different sizes in each ball throwing device, and arrange them from small to large in order of size: D1, D2, ..., D n , the ball throwing devices are marked as the first ball throwing device, the second ball throwing device, ..., the nth ball throwing device according to the corresponding temporary blocking ball diameter from small to large;

[0012] Step 2: After fracturing begins, keep the first plug valve and the second plug valve closed; when the sand adding stage begins and the injection volume of the fracturing vehicle group reaches 1 / 8 of the total, start to release the temporary plugging balls; when releasing, first open the second plug valve, then open the first plug valve, and then let the temporary plugging ball delivery device deliver the temporary plugging balls in the order of small to large temporary plugging balls;

[0013] Step three, using a microseismic detector and a pressure measuring device to detect the fracturing of the rock formation, when the temporary plugging pressure increase change value is low or the microseismic monitoring of the new crack opening effect is not obvious, first close the first ball-dropping device, open the second ball-dropping device, continue to drop at the set speed, and record the pumping fluid volume of the fracturing vehicle group; when the pumping fluid volume exceeds 1.2 wellbore volumes, the temporary plugging effect is judged again by the microseismic detector and the pressure measuring device. If the effect is improved, continue to use the second ball-dropping device. If it is still not obvious, switch to the next ball-dropping device for drop;

[0014] Step 4: Detect the rock fracturing situation through microseismic detectors and pressure measuring devices. When the fracturing effect is achieved, first stop the equipment deployment, then close the second plug valve, and finally close the first plug valve to isolate the equipment from the main line.

[0015] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0016] 1. The slot stepless steering system of the present invention realizes the flexible filling of temporary blocking balls through the unique temporary blocking ball delivery device design and plug valve isolation mechanism, which significantly improves the construction efficiency and operation convenience. First, the temporary storage bottle of the temporary blocking ball delivery device is equipped with a ball delivery valve and a delivery tube, so that in the operation of the system, in addition to the temporary blocking ball loading through the first plug valve and the second plug valve, the temporary blocking ball can also be replenished in real time during the fracturing process. This design benefits from the structure of the rotating piston: the side wall of the rotating piston is only provided with a ball delivery hole, and the other two through holes on the side wall of the five-way connecting pipe are closed by the solid circumferential side wall of the rotating piston. Therefore, during the operation, the temporary storage bottles corresponding to the two closed through holes can open the ball delivery valve at any time to load the temporary blocking balls. This flexible filling method not only reduces the construction interruption time, but also reduces the operating cost, and is particularly suitable for long-term and large-scale fracturing operations. In addition, the isolation design of the first plug valve and the second plug valve ensures that the fracturing fluid will not flow back or leak during the filling process, further improving the safety and reliability of the construction. Through this flexible filling mechanism, the system can adapt to complex and changeable fracturing conditions and ensure the continuous supply of temporary plugging balls, thereby optimizing the fracturing effect and improving the overall construction efficiency;

[0017] 2. The slot stepless steering system of the present invention has the ability to accurately deliver temporary plugging balls of different sizes, and can flexibly adjust the delivery order and quantity of temporary plugging balls according to the fracturing requirements, which significantly improves the fracturing effect and crack expansion efficiency. The system realizes the selective connection of multiple ball-casting devices and the precise delivery of temporary plugging balls through the coordinated work of the first drive device and the five-way connecting pipe, ensuring the optimal delivery amount of temporary plugging balls of different sizes. The first drive device includes a first motor, a planetary gear set, an electromagnet and a round iron plate. The intelligent controller selectively turns on the electromagnet to control the rotation of a specific round iron plate, thereby driving the corresponding spiral conveying blade to transport the temporary plugging ball to the five-way connecting pipe (the magnetic transmission design of the electromagnet and the round iron plate also ensures that the equipment can still be in a safe operating state after being stuck). In addition, the design of the rotating piston enables the system to select a specific ball-casting device to connect its ball-casting hole as needed, ensuring that the temporary plugging ball is accurately delivered as needed. This precise delivery capability is particularly suitable for multi-stage fracturing operations. It can dynamically adjust the size and delivery sequence of temporary plugging balls according to rock formation characteristics and fracturing progress, thereby effectively guiding the fracturing fluid to the target area and enhancing the crack expansion effect. At the same time, the system further improves the stability and reliability of temporary plugging ball delivery through the isolation design of the plug valve and the vertical sliding function of the rotating piston, avoiding the direct impact of high-pressure fluid on the equipment and extending the service life of the equipment. In summary, the system significantly improves the flexibility and effect of fracturing construction by accurately delivering temporary plugging balls of different sizes, providing effective technical support for the efficient development of unconventional oil and gas resources. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The drawings described herein are used to provide a further understanding of the embodiments of the present invention, constitute a part of this application, and do not constitute a limitation of the embodiments of the present invention. In the drawings:

[0019] Figure 1 is the overall flow chart of the system of this embodiment;

[0020] Figure 2 Take the structural diagram of the temporary blocking ball delivery device as an example;

[0021] Figure 3 For temporary blocking ball delivery device relative to Figure 2 Another perspective structural diagram;

[0022] Figure 4 This is a schematic diagram of the first cutting structure of the temporary blocking ball delivery device;

[0023] Figure 5 This is a schematic diagram of the second cutting structure of the temporary blocking ball delivery device;

[0024] Figure 6 This is a schematic diagram of the third cutting structure of the temporary blocking ball delivery device;

[0025] Figure 7 This is a schematic diagram of the fourth cutting structure of the temporary blocking ball delivery device;

[0026] Figure 8 This is a schematic diagram of the fifth cutting structure of the temporary blocking ball delivery device;

[0027] Fig. 9 This is a schematic diagram of the sixth cutting structure of the temporary blocking ball delivery device;

[0028] Fig.10 This is a schematic diagram of the seventh cutting structure of the temporary blocking ball delivery device;

[0029] Fig.11 for Fig.10 Detailed diagram at A in the middle;

[0030] Fig.12 This is a schematic diagram of the eighth cutting structure of the temporary blocking ball delivery device;

[0031] Fig.13 for Fig.12 Detailed diagram at B in the middle;

[0032] Fig.14 This is a schematic diagram of the ninth cutting structure of the temporary blocking ball delivery device;

[0033] Fig.15 This is a schematic diagram of the tenth cutting structure of the temporary blocking ball delivery device;

[0034] Fig.16 This is a schematic diagram of the eleventh cutting structure of the temporary blocking ball delivery device;

[0035] Fig.17 is a schematic diagram of the structure of the fourth rotating shaft;

[0036] Fig.18 It is a schematic diagram of the rotating piston structure.

[0037] The reference numerals represent: 1-first motor, 2-driving disk, 3-delivery cylinder, 4-ball delivery valve, 5-rotating rod, 6-temporary storage bottle, 7-five-way connecting pipe, 8-first driving gear, 9-first driven gear, 10-electromagnet, 11-first rotating shaft, 12-round iron plate, 13-second rotating shaft, 14-clutch, 15-third rotating shaft, 16-fourth rotating shaft, 17-polygonal rod, 18-polygonal hole, 19-second motor, 20-second driven gear, 21-second driving gear, 22-screw rod, 23-limiting box, 24-spiral conveying blade, 25-rotating piston, 26-ball delivery hole. DETAILED DESCRIPTION

[0038] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with embodiments and drawings. The exemplary embodiments of the present invention and their description are only used to explain the present invention and are not intended to limit the present invention.

[0039] like Figures 1 to 18 As shown, the present embodiment relates to a seam stepless steering system, comprising a fracturing vehicle group, a fracturing main line and a fracturing branch line, the fracturing vehicle group can transport fracturing fluid through the fracturing main line and the fracturing branch line to fracture the rock formation, and the fracturing branch line can add temporary plugging balls to the fracturing fluid; the fracturing branch line comprises a first plug valve, a second plug valve and a temporary plugging ball delivery device, wherein the temporary plugging ball delivery device is arranged between the first plug valve and the second plug valve; the embodiment system adopts the first plug valve and the second plug valve to isolate the temporary plugging ball delivery device in the fracturing branch line, which can effectively control the timing and sequence of temporary plugging ball delivery, avoid fracturing fluid backflow or leakage, and improve construction safety; at the same time, the isolation design of the plug valve reduces the direct impact of high-pressure fluid on the delivery device, prolongs the equipment life, and facilitates maintenance and overhaul, ensuring that the temporary plugging balls are accurately delivered on demand, optimizing the fracturing effect, and enhancing the efficiency of crack expansion.

[0040] Among them, the specific structure of the temporary blocking ball delivery device includes a first driving device, multiple ball delivery devices and a five-way connecting pipe 7. The first driving device includes a first motor 1, a planetary gear set, an electromagnet 10 and a round iron plate 12 (the electromagnet 10 and the round iron plate 12 are close to each other but not in contact, and the planetary gear set, the electromagnet 10 and the round iron plate 12 constitute a driving plate 2). Among them, the planetary gear set includes a first driving gear 8 and multiple first driven gears 9. The first driving gear 8 is fixed by a first rotating shaft 11, and the first motor 1 is coaxially connected to the first rotating shaft 11.

[0041] Furthermore, electromagnets 10 are disposed at the bottom of the plurality of first driven gears 9 , and rotatable round iron plates 12 are disposed at the bottom of the electromagnets 10 in correspondence with each other. The round iron plates 12 are coaxial with the corresponding first driven gears 9 . A third rotating shaft 15 is also coaxially arranged vertically below the first rotating shaft 11, and the first rotating shaft 11 and the third rotating shaft 15 are connected through a clutch 14 (the clutch 14 is arranged so that the rotation of the first rotating shaft 11 will not directly affect the third rotating shaft 15. When the first rotating shaft 11 does not need to transmit power to the third rotating shaft 15, the power of the first rotating shaft 11 is separated, and the position of the third rotating shaft 15 is locked by the clutch 14. When the first rotating shaft 11 is required to drive the third rotating shaft 15 to rotate, the power is transmitted to the third rotating shaft 15 through the clutch 14. The clutch control design of the first rotating shaft 11 and the third rotating shaft 15 enables the first rotating shaft 11 to control the angle of the rotating piston 25 in the five-way connecting pipe 7, so that the rotating piston 25 can control the connection state of the ball pitching device and the five-way pipe according to demand, that is, open the delivery port of a certain ball pitching device). A fourth rotating shaft 16 is also arranged vertically below the third rotating shaft 15, and the fourth rotating shaft 16 is movably connected to the third rotating shaft 15. When the first motor 1 is driven, the first rotating shaft 11 rotates accordingly. During the rotation of the first rotating shaft 11, it drives the first driven gears 9 to rotate through the first driving gear 8. The rotation of the first driven gear 9 drives the corresponding electromagnet 10 to rotate. When the electromagnet 10 is not energized, the round iron disk 12 corresponding to the electromagnet 10 does not rotate. When the electromagnet 10 is energized, the round iron disk 12 can rotate under the action of magnetic force (when the first motor 1 rotates, multiple electromagnets 10 will rotate. By selectively turning on the electromagnet 10 through the intelligent controller, some of the round iron disks 12 can be selectively driven to rotate. The round iron disk 12 drives the spiral conveying blade 24 to rotate through the second rotating shaft 13 connected thereto, thereby controlling and conveying the temporarily blocked ball in a certain ball pitching device).

[0042] Furthermore, the third rotating shaft 15 is coaxially provided with a polygonal hole 18 facing vertically downward, and a polygonal rod 17 is provided at the vertical upper part of the fourth rotating shaft 16 corresponding to the third rotating shaft 15, and the polygonal rod 17 is matched with the polygonal hole 18 (that is, the fourth rotating shaft 16 can slide up and down in the polygonal hole 18 of the third rotating shaft 15 through the polygonal rod 17, and it cannot rotate relative to the third rotating shaft 15); a screw rod 22 is provided in the middle part of the fourth rotating shaft 16, and the screw rod 22 is coupled with the second driven gear 20 with an internal thread, and the second driven gear 20 is meshed with the second driving gear 21, and the second driving gear 21 and the second driven gear 20 are arranged in a limit box 23 (the limit box 23 limits the second driven gear 20 and the second driving gear 21 The limit box 23 is fixed to the third rotating shaft 15, and the limit box 23 is also fixed with the second motor 19, and the second motor 19 drives the second driving gear 21 to rotate (the relative extension and contraction of the third rotating shaft 15 and the fourth rotating shaft 16 that cannot rotate is beneficial to the angle control of the rotating piston 25, and the vertical sliding of the rotating piston 25, and the three temporary plugging ball delivery ports in the five-way pipe are closed by the solid circumferential side wall of the rotating piston 25, so as to cope with the situation that the fracturing pressure of the pipeline is large and the temporary plugging ball delivery device bursts during the actual fracturing operation).

[0043] Furthermore, the five-way connecting pipe 7 is composed of three horizontal pipes of the same size arranged around the circumference of a vertical pipe, the upper end of the vertical pipe is closed by a flange, a rotating piston 25 is arranged inside the vertical pipe, the rotating piston 25 is provided with a circular cavity facing vertically downward, and a ball throwing hole 26 is arranged on the circumferential side of the rotating piston 25, and the rotating piston 25 can be connected to any one of the three horizontal pipes through the ball throwing hole 26; the fourth rotating shaft 16 extends vertically downward through the flange and is connected to the rotating piston 25, and the fourth rotating shaft 16 can drive the rotating piston 25 to rotate or slide in the vertical direction.

[0044] A plurality of ball throwing devices are respectively provided with temporary storage bottles 6, each temporary storage bottle 6 corresponds to a round iron plate 12 one by one, each temporary storage bottle 6 is connected to a five-way connecting pipe 7 through a pipe arranged at the bottom, a vertical spiral conveying blade 24 is arranged in the pipe, and the spiral conveying blade 24 is driven by a second rotating shaft 13 arranged in the temporary storage bottle 6, and the second rotating shaft 13 extends vertically upward and is connected to the corresponding round iron plate 12. In the embodiment, the temporary storage bottle 6 of the temporary blocking ball throwing device is also provided with a ball throwing valve 4 (the ball throwing valve 4 is controlled to open and close by a rotating rod 5), and a throwing cylinder 3 is also arranged on the ball throwing valve 4. In the operation process of the embodiment, in addition to being able to In addition to being able to load the temporary blocking ball through the cooperation of the first stopcock and the second stopcock, the temporary blocking ball can also be loaded during operation (the rotating piston 25 has only one ball throwing hole 26 on the side wall. During the operation, the solid circumferential side wall of the rotating piston 25 will always be connected to a through hole on the side wall of the five-way tube, closing the through holes of the other two five-way connecting tubes 7. Therefore, the temporary storage bottles 6 corresponding to the two closed holes can be filled during operation), open the ball throwing valve 4 corresponding to the closed ball throwing port temporary storage bottle 6, and complete the loading of the temporary blocking ball, so that the temporary blocking ball loading method of this embodiment is faster and has lower operating costs.

[0045] Embodiment A slot continuously variable steering system also relates to an application method, wherein the slot continuously variable steering system is implemented, comprising the following steps:

[0046] Step 1: Place temporary blocking balls of different sizes in each pitching device, and arrange them in ascending order of size as D1, D2, ..., Dn. The pitching devices are marked in ascending order of diameter of the corresponding temporary blocking balls as the first pitching device, the second pitching device, ..., the nth pitching device;

[0047] Step 2: After fracturing begins, keep the first plug valve and the second plug valve closed; when the sand adding stage begins and the injection volume of the fracturing vehicle group reaches 1 / 8 of the total, start to release the temporary plugging balls; when releasing, first open the second plug valve, then open the first plug valve, and then let the temporary plugging ball delivery device deliver the temporary plugging balls in the order of small to large temporary plugging balls;

[0048] Step three, detect the rock formation fracturing situation through the microseismic detector and the pressure measuring device. When the temporary plugging pressure increase change value is low (for example, lower than 3Mpa, 5MPa or other values, the specific value is determined according to the actual working conditions) or the microseismic monitoring of the new crack opening effect is not obvious, first close the first ball throwing device, open the second ball throwing device, continue to throw at the set speed, and record the pumping fluid volume of the fracturing vehicle group; when the pumping fluid volume exceeds 1.2 wellbore volumes, judge the temporary plugging effect again through the microseismic detector and the pressure measuring device. If the effect is improved, continue to use the second ball throwing device. If it is still not obvious, switch to the next ball throwing device for throwing;

[0049] Step 4: Detect the rock fracturing situation through microseismic detectors and pressure measuring devices. When the fracturing effect is achieved, first stop the equipment deployment, then close the second plug valve, and finally close the first plug valve to isolate the equipment from the main line.

[0050] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A seam stepless steering system, comprising a fracturing vehicle group, a fracturing main pipeline and a fracturing branch pipeline, characterized in that: The fracturing vehicle group can deliver fracturing fluid through the fracturing main line and the fracturing branch line to fractur e the rock formation, and the fracturing branch line can add temporary plugging balls into the fracturing fluid; The fracturing branch pipeline comprises a first plug valve, a second plug valve and a temporary plugging ball delivery device, wherein the temporary plugging ball delivery device is arranged between the first plug valve and the second plug valve; The temporary blocking ball delivery device comprises a first driving device, a plurality of ball delivery devices and a five-way connecting pipe (7), wherein the plurality of ball delivery devices are connected to the five-way connecting pipe (7), and the first driving device can selectively connect the ball delivery devices to the five-way connecting pipe (7), and can selectively deliver the temporary blocking balls in the ball delivery devices to the five-way connecting pipe (7); The first driving device comprises a first motor (1), a planetary gear set, an electromagnet (10) and a round iron plate (12), wherein the planetary gear set comprises a first driving gear (8) and a plurality of first driven gears (9), the first driving gear (8) is fixed by a first rotating shaft (11), and the first motor (1) is coaxially connected to the first rotating shaft (11); The bottoms of the plurality of first driven gears (9) are each provided with an electromagnet (10), and the bottoms of the electromagnets (10) are provided with rotatable round iron plates (12) in correspondence with each other, and the round iron plates (12) are coaxial with the corresponding first driven gears (9).

2. A slotted stepless steering system as claimed in claim 1, characterized in that: A third rotating shaft (15) is coaxially arranged vertically below the first rotating shaft (11); the first rotating shaft (11) and the third rotating shaft (15) are connected via a clutch (14); a fourth rotating shaft (16) is vertically arranged below the third rotating shaft (15); the fourth rotating shaft (16) is movably connected to the third rotating shaft (15).

3. A slotted stepless steering system as claimed in claim 2, characterized in that: The third rotating shaft (15) is coaxially provided with a polygonal hole (18) facing vertically downwards; a polygonal rod (17) is provided on the vertical upper part of the fourth rotating shaft (16) corresponding to the third rotating shaft (15); the polygonal rod (17) is engaged with the polygonal hole (18); a screw rod (22) is provided in the middle part of the fourth rotating shaft (16); the screw rod (22) is coupled with a second driven gear (20) having an internal thread; the second driven gear (20) is meshed with a second driving gear (21); the second driving gear (21) and the second driven gear (20) are arranged in a limit box (23); the limit box (23) is fixed to the third rotating shaft (15); a second motor (19) is also fixed to the limit box (23); the second motor (19) drives the second driving gear (21) to rotate.

4. A slotted stepless steering system as claimed in claim 3, characterized in that: The five-way connecting pipe (7) is composed of a vertical pipe and three horizontal pipes of the same size arranged around the vertical pipe on a circumference. The upper end of the vertical pipe is closed by a flange. A rotating piston (25) is arranged inside the vertical pipe. The rotating piston (25) is provided with a circular cavity facing vertically downward. A ball-casting hole (26) is arranged on the circumferential side of the rotating piston (25). The rotating piston (25) can be connected to any one of the three horizontal pipes through the ball-casting hole (26). A fourth rotating shaft (16) extends vertically downward through the flange and is connected to the rotating piston (25). The fourth rotating shaft (16) can drive the rotating piston (25) to rotate or slide in a vertical direction.

5. A slotted stepless steering system as claimed in claim 1, characterized in that: The plurality of ball throwing devices are respectively provided with temporary storage bottles (6), each temporary storage bottle (6) corresponds to a round iron plate (12) one by one, each temporary storage bottle (6) is connected to a five-way connecting pipe (7) via a pipeline provided at the bottom, a vertical spiral conveying blade (24) is provided in the pipeline, and the spiral conveying blade (24) is driven by a second rotating shaft (13) provided in the temporary storage bottle (6), and the second rotating shaft (13) extends vertically upward and is connected to the corresponding round iron plate (12).

6. An application method of a slot continuously variable steering system, which is implemented by using a slot continuously variable steering system according to any one of claims 1 to 5, characterized in that: The following steps are involved: Step 1: Place temporary blocking balls of different sizes in each pitching device, and arrange them in ascending order of size as D1, D2, ..., Dn. The pitching devices are marked in ascending order of diameter of the corresponding temporary blocking balls as the first pitching device, the second pitching device, ..., the nth pitching device; Step 2: After fracturing begins, keep the first plug valve and the second plug valve closed; when the sand adding stage begins and the injection volume of the fracturing vehicle group reaches 1 / 8 of the total, start to release the temporary plugging balls; when releasing, first open the second plug valve, then open the first plug valve, and then let the temporary plugging ball delivery device deliver the temporary plugging balls in the order of small to large temporary plugging balls; Step three, using a microseismic detector and a pressure measuring device to detect the fracturing of the rock formation, when the temporary plugging pressure rise change value is lower than a predetermined value, first close the first ball-dropping device, open the second ball-dropping device, continue to drop at the set speed, and record the pumping liquid volume of the fracturing vehicle group; when the pumping liquid volume exceeds 1.2 wellbore volumes, the temporary plugging effect is judged again by the microseismic detector and the pressure measuring device, if the effect is improved, continue to use the second ball-dropping device, if it is still not obvious, switch to the next ball-dropping device for drop; Step 4: Detect the rock fracturing situation through microseismic detectors and pressure measuring devices. When the fracturing effect is achieved, first stop the equipment deployment, then close the second plug valve, and finally close the first plug valve to isolate the equipment from the main line.

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