Hydraulic type jam-releasing and backing-pressure-preventing tool

Abstract

The utility model discloses a hydraulic type jam releasing and backing pressure preventing tool, which belongs to the technical field of well drilling downhole tools and comprises a drill rod mandrel, a plugging connector, a hydraulic cylinder body, a jarring block, a two-way hydraulic control one-way valve, a buffer piston and a baffle ring, a first step and a second step are arranged in the hydraulic cylinder body, and the plugging connector is connected with the hydraulic cylinder body. The drill rod mandrel is in sliding connection with the plugging connector, the jarring block is fixedly installed on the drill rod mandrel in the circumferential direction, the two-way hydraulic control one-way valve is fixedly arranged on the drill rod mandrel, the buffer piston and the baffle ring are installed on a first step of the hydraulic cylinder in a combined mode, and ascending limiting of the drill rod mandrel is limited by the jarring block and the plugging connector. Downward limiting of the drill rod mandrel is limited by the second step, and during normal work, the drill rod mandrel is in tight contact with the second step to transmit bit pressure.

Description

Technical Field

[0001] The utility model relates to the technical field of downhole tools for oil mining and drilling, in particular to a hydraulic type jam-releasing and pressure-preventing tool. Background Art

[0002] During oil drilling operations, the drill string may get stuck due to many factors such as complex and changeable formation structure, changes in well inclination angle, poor wellbore quality and improper construction, resulting in drill bit support. If it cannot be handled promptly and accurately, the production cycle will be extended and the drilling efficiency will be affected. In more serious cases, the accident may be further aggravated, resulting in the scrapping of the drilled wellbore. One of the important existing solutions is to use the impact force generated by the jar to achieve the purpose of unblocking.

[0003] Among the existing jars, hydraulic jars and mechanical jars are still the mainstream jar unblocking technologies, and mechanical hydraulic jar technology will be an important development direction in the future. Hydraulic jars mainly rely on the internal hydraulic oil to release the pressure to generate a strong impact force to make the drill string subject to a strong impact to achieve the purpose of unblocking. Mechanical jars mainly rely on the elastic sleeve to deform under the action of pressure to release the slip pair to generate a force to unblock the drill bit. However, the existing hydraulic jars have a complex structural design. If a single hydraulic jar is damaged, the jar unblocking effect will be affected, or even completely unable to achieve the unblocking effect, and it does not have the active unblocking function while drilling. The mechanical jar has a single amplitude, is easy to wear during axial movement, and has a high maintenance cost. Utility Model Content

[0004] In order to solve the above problems in the prior art, the utility model provides a hydraulic unblocking and anti-pressure tool. The tool follows the working principle of the hydraulic jar, but is significantly simplified in structure, and adopts a two-way hydraulically controlled one-way valve to realize energy storage and release control.

[0005] The purpose of this utility model is achieved through the following technical solutions:

[0006] A hydraulic unblocking and anti-pressure tool comprises a drill pipe spindle, a plugging joint, a hydraulic cylinder, a jar block, a two-way hydraulically controlled one-way valve, a buffer piston and a retaining ring, wherein a first step and a second step are arranged inside the hydraulic cylinder, the plugging joint is connected to the hydraulic cylinder, the drill pipe spindle is slidably connected to the plugging joint, the jar block is circumferentially fixedly mounted on the drill pipe spindle, the two-way hydraulically controlled one-way valve is fixedly mounted on the drill pipe spindle, the buffer piston and the retaining ring are assembled and mounted on the first step of the hydraulic cylinder, the upward limit of the drill pipe spindle is limited by the jar block and the plugging joint, and the downward limit of the drill pipe spindle is limited by the second step. During normal operation, the drill pipe spindle is in close contact with the second step to transmit drilling pressure.

[0007] Preferably, the bidirectional hydraulically controlled one-way valve comprises an upper valve cover, a valve body, a lower valve cover, a first cone valve seat, a pilot valve seat, a first cone valve, a first cone valve spring, a pilot valve and a pilot valve spring. The upper valve cover, valve body and lower valve cover are arranged in sequence, and the first cone valve seat, the first cone valve spring, the first cone valve, the pilot valve spring, the pilot valve seat and the pilot valve are arranged in sequence to form a reverse hydraulically controlled one-way valve; the pilot valve, the pilot valve seat, the pilot valve spring, the first cone valve, the first cone valve spring and the first cone valve seat are arranged in sequence to form a forward hydraulically controlled one-way valve; the upper valve cover, valve body and lower valve cover are provided with a reverse hydraulically controlled one-way valve and a forward hydraulically controlled one-way valve.

[0008] Preferably, the upper valve cover is provided with an upper oil outlet, an upper hydraulic control port, an upper oil inlet, an upper pilot valve hole, an upper cone valve hole and a first flow channel, and the first flow channel is communicated with the upper pilot valve port.

[0009] Preferably, the valve body is provided with a first oil outlet, a second oil outlet, a middle guide valve hole, a middle cone valve hole, a second flow channel and a first valve port, the second flow channel is connected with the middle cone valve hole, and the first oil outlet and the second oil outlet are respectively connected with the bottom surface of the middle guide valve hole on the two end surfaces of the valve body.

[0010] Preferably, the lower valve cover is provided with a lower oil outlet, a lower hydraulic control port, a lower oil inlet, a lower pilot valve hole, a lower cone valve hole and a third flow channel, and the third flow channel is connected to the lower pilot valve hole.

[0011] Preferably, a first stress-bearing surface, a second stress-bearing surface and a third stress-bearing surface are arranged on the pilot valve, and the pilot valve is installed in a hole formed by an upper pilot valve hole and a middle pilot valve hole; or the pilot valve is installed in a hole formed by a lower pilot valve hole and a middle pilot valve hole, and the pilot valve spring is arranged between the second stress-bearing surface and the third stress-bearing surface. When the pilot valve is installed in a mounting hole formed by an upper valve cover and a valve body, the first stress-bearing surface should be flush with the first flow channel when not subjected to hydraulic pressure, ensuring that hydraulic oil can enter without resistance; when the pilot valve is installed in a mounting hole formed by a lower valve cover and a valve body, the first stress-bearing surface should be flush with the third flow channel when not subjected to hydraulic pressure, ensuring that hydraulic oil can enter without resistance. After the pilot valve is installed, the pilot valve seat should be threadedly connected to the valve cover for limiting.

[0012] Preferably, the first cone valve is installed in a cone valve hole formed by a middle cone valve hole on the valve body and an upper cone valve hole on the upper valve cover; or the first cone valve is installed in a cone valve hole formed by a lower cone valve hole on the lower valve cover, and the first cone valve is in close contact with the large end of the first valve port through a first cone valve spring.

[0013] Preferably, the upper valve cover, the valve body and the lower valve cover are respectively provided with an upper threaded hole, a middle threaded hole and a lower threaded hole, and the upper valve cover, the valve body and the lower valve cover are connected through the upper threaded hole, the middle threaded hole, the lower threaded hole and bolts.

[0014] The beneficial effects of this technical solution are as follows:

[0015] 1. The utility model provides a hydraulic unblocking and anti-pressure tool. The tool follows the working principle of the hydraulic jar, but is significantly simplified in structure, and adopts a two-way hydraulically controlled one-way valve to realize energy storage and release control.

[0016] 2. The utility model provides a hydraulic unblocking and anti-pressure tool. The two-way hydraulic-controlled one-way valve separates the hydraulic cylinder into an upper hydraulic chamber and a lower hydraulic chamber. The two-way hydraulic-controlled one-way valve is provided with a reverse hydraulic-controlled one-way valve and a forward hydraulic-controlled one-way valve. The upper hydraulic chamber and the lower hydraulic chamber are filled with hydraulic oil. In order not to affect normal drilling and cause sudden pressure build-up and impact, the hydraulic oil in the upper hydraulic chamber and the lower hydraulic chamber should not be completely filled, and a certain space should be left. When the drill bit is stuck or is stuck, the drill string is lifted up. At this time, the drill pipe core shaft drives the two-way hydraulic-controlled one-way valve to move upward. When the reserved space in the upper hydraulic chamber is compensated by the moving distance, the hydraulic oil in the upper hydraulic chamber begins to be built up. When the pressure relief condition is reached, the pressure can be released to release the energy impact of the drill string, which has a vibration and decompression effect on the drill string. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the structure of the utility model;

[0018] Figure 2 It is a structural schematic diagram of a bidirectional hydraulically controlled one-way valve in the utility model;

[0019] Figure 3 It is a cross-sectional view of a bidirectional hydraulically controlled one-way valve in the utility model;

[0020] Figure 4 It is a structural schematic diagram of the valve body in the utility model;

[0021] Figure 5 It is a cross-sectional view of the valve body in the utility model;

[0022] Figure 6 The structure of the upper valve cover in the utility model is shown in FIG. Figure 1 ;

[0023] Figure 7 The structure of the upper valve cover in the utility model is shown in FIG. Figure 2 ;

[0024] Figure 8 The structure of the lower valve cover in the utility model is shown in FIG. Figure 1 ;

[0025] Fig. 9 The structure of the lower valve cover in the utility model is shown in FIG. Figure 2 ;

[0026] Fig.10 This is a schematic diagram of the structure of the pilot valve in the utility model;

[0027] Fig.11 It is a cross-sectional view of the pilot valve in the utility model;

[0028] In the figure: 110, drill pipe mandrel; 120, plugging joint; 130, hydraulic cylinder; 131, first step; 132, second step; 140, shock block; 150, two-way hydraulic control check valve; 151, upper valve cover; 1511, upper oil outlet; 1512, upper hydraulic control port; 1513, upper oil inlet; 1514, upper pilot valve hole; 1515, upper cone valve hole; 1516, first flow channel; 1517, upper threaded hole; 152, valve body; 1521, first oil outlet; 1522, second oil outlet; 1523, middle pilot valve hole; 1524, middle cone valve hole; 1525, second flow channel; 1526, first A valve port; 1527, middle threaded hole; 153, lower valve cover; 1531, lower oil outlet; 1532, lower hydraulic control port; 1533, lower oil inlet; 1534, lower pilot valve hole; 1535, lower cone valve hole; 1536, third flow channel; 1537, lower threaded hole; 154, first cone valve seat; 155, pilot valve seat; 156, first cone valve; 157, first cone valve spring; 158, pilot valve; 1581, first force surface; 1582, second force surface; 1583, third force surface; 159, pilot valve spring; 160, buffer piston; 170, retaining ring 400, upper hydraulic chamber; 500, lower hydraulic chamber; 800, reverse hydraulic control one-way valve; 900, forward hydraulic control one-way valve. DETAILED DESCRIPTION

[0029] The present invention is further described in detail below in conjunction with the embodiments, but the implementation manner of the present invention is not limited thereto.

[0030] It should be noted that when a component is referred to as being "mounted on", "fixed on" or "disposed on" another component, it may be directly on the other component or there may be a central component at the same time. When a component is referred to as being "connected to" another component, it may be directly connected to the other component or there may be a central component at the same time.

[0031] It should also be noted that the directional terms such as left, right, up, and down in the embodiments of the present invention are merely relative concepts or are based on the normal use status of the product and should not be considered as restrictive.

[0032] Example 1

[0033] like Figure 1-Figure 11As shown, a hydraulic unblocking and anti-pressure tool comprises a drill pipe mandrel 110, a plugging joint 120, a hydraulic cylinder 130, a shock block 140, a two-way hydraulically controlled one-way valve 150, a buffer piston 160 and a retaining ring 170, wherein the hydraulic cylinder 130 is provided with a first step 131 and a second step 132, the plugging joint 120 is connected to the hydraulic cylinder 130, the drill pipe mandrel 110 is slidably connected to the plugging joint 120, and the shock block 140 is circumferentially fixedly arranged. Installed on the drill pipe spindle 110, the two-way hydraulically controlled one-way valve 150 is fixedly arranged on the drill pipe spindle 110, the buffer piston 160 and the retaining ring 170 are installed in combination on the first step 131 of the hydraulic cylinder body 130, the upward limit of the drill pipe spindle 110 is limited by the shock block 140 and the sealing joint 120, and the downward limit of the drill pipe spindle 110 is limited by the second step 132. During normal operation, the drill pipe spindle 110 is in close contact with the second step 132 to transmit the drilling pressure.

[0034] Example 2

[0035] The difference between this embodiment and embodiment 1 is that the bidirectional hydraulically controlled one-way valve 150 includes an upper valve cover 151, a valve body 152, a lower valve cover 153, a first cone valve seat 154, a pilot valve seat 155, a first cone valve 156, a first cone valve spring 157, a pilot valve 158 and a pilot valve spring 159. The upper valve cover 151, the valve body 152 and the lower valve cover 153 are arranged in sequence. The first cone valve seat 154, the first cone valve spring 157, the first cone valve 158 and the pilot valve spring 159 are arranged in sequence. 6. The pilot valve spring 159, the pilot valve seat 155 and the pilot valve 158 are sequentially arranged to form a reverse hydraulically controlled one-way valve 800; the pilot valve 158, the pilot valve seat 155, the pilot valve spring 159, the first cone valve 156, the first cone valve spring 157 and the first cone valve seat 154 are sequentially arranged to form a forward hydraulically controlled one-way valve 900; the upper valve cover 151, the valve body 152 and the lower valve cover 153 are provided with a reverse hydraulically controlled one-way valve 800 and a forward hydraulically controlled one-way valve 900.

[0036] The upper valve cover 151 is provided with an upper oil outlet 1511 , an upper hydraulic control port 1512 , an upper oil inlet 1513 , an upper pilot valve hole 1514 , an upper cone valve hole 1515 and a first flow channel 1516 , and the first flow channel 1516 is communicated with the upper pilot valve 158 port.

[0037] Among them, the valve body 152 is provided with a first oil outlet 1521, a second oil outlet 1522, a middle guide valve hole 1523, a middle cone valve hole 1524, a second flow channel 1525 and a first valve port 1526, the second flow channel 1525 is connected with the middle cone valve hole 1524, and the first oil outlet 1521 and the second oil outlet 1522 are respectively connected with the bottom surface of the middle guide valve hole 1523 on the two end surfaces of the valve body 152.

[0038] The lower valve cover 153 is provided with a lower oil outlet 1531 , a lower hydraulic control port 1532 , a lower oil inlet 1533 , a lower pilot valve hole 1534 , a lower cone valve hole 1535 and a third flow channel 1536 , and the third flow channel 1536 is communicated with the lower pilot valve hole 1534 .

[0039] The pilot valve 158 is provided with a first force-bearing surface 1581, a second force-bearing surface 1582 and a third force-bearing surface 1583. The pilot valve 158 is installed in a hole formed by the upper pilot valve hole 1514 and the middle pilot valve hole 1523; or the pilot valve 158 is installed in a hole formed by the lower pilot valve hole 1534 and the middle pilot valve hole 1523, and the pilot valve spring 159 is arranged between the second force-bearing surface 1582 and the third force-bearing surface 1583. When the pilot valve 158 is installed on the upper valve cover 151 and the valve body 152 When the pilot valve 158 is installed in the mounting hole formed on the lower valve cover 153 and the valve body 152, the first force surface 1581 should be flush with the third flow channel 1536 when not affected by the hydraulic pressure, ensuring that the hydraulic oil can enter without resistance. After the pilot valve 158 is installed, the pilot valve seat 155 should be threadedly connected to the valve cover for limiting.

[0040] Among them, the first cone valve 156 is installed in the cone valve hole formed by the middle cone valve hole 1524 on the valve body 152 and the upper cone valve hole 1515 on the upper valve cover 151; or the first cone valve 156 is installed in the cone valve hole formed by the lower cone valve hole 1535 on the lower valve cover 153, and the first cone valve 156 is in close linear contact with the large end of the first valve port 1526 through the first cone valve spring 157.

[0041] Among them, the upper valve cover 151, the valve body 152 and the lower valve cover 153 are respectively provided with an upper threaded hole 1517, a middle threaded hole 1527 and a lower threaded hole 1537, and the upper valve cover 151, the valve body 152 and the lower valve cover 153 are connected with bolts through the upper threaded hole 1517, the middle threaded hole 1527, the lower threaded hole 1537.

[0042] Opening principle of two-way hydraulically controlled check valve 150 (taking the forward hydraulically controlled check valve 900 as an example)

[0043] When the drill pipe spindle 110 drives the two-way hydraulically controlled one-way valve 150 to move downward, since the first cone valve 156 and the first valve port 1526 are in close line contact under the action of the first cone valve spring 157, the hydraulic oil will not be able to enter the upper hydraulic chamber 400 from the lower end of the forward hydraulically controlled one-way valve 900 through the first valve port 1526. Since the drill pipe spindle 110 moves downward, the hydraulic oil in the upper hydraulic chamber 400 is not pressurized, which can be understood as a pressure of 0. Therefore, the pilot valve 158 will not move, and the maximum diameter of the third force-bearing surface 1583 at the lower part of the pilot valve 158 will cooperate with the minimum diameter of the first valve port 1526. The pilot valve 158 does not move, and the hydraulic oil in the upper hydraulic chamber 400 will not be able to enter the lower hydraulic chamber 500 through the forward hydraulically controlled one-way valve.

[0044] When the drill pipe mandrel 110 moves upward, the drill pipe mandrel 110 drives the bidirectional hydraulically controlled one-way valve 150 to move upward, the reserved space is completely compressed, and the hydraulic oil in the upper hydraulic chamber 400 begins to be pressurized. The force analysis of the pilot valve 158 in the forward hydraulically controlled one-way valve 900 shows the equilibrium equation when the pilot valve is under force:

[0045] P1•A1+P3•A3=P2•A2+F T1

[0046] When the upper hydraulic chamber 400 is compressed, the internal hydraulic oil will transfer the pressure to the first force-bearing surface 1581 (the effective area of ​​the first force-bearing surface 1581 is A1) through the upper hydraulic control port 1512 and apply a thrust P1•A1. At the same time, it enters the annular cavity formed by the second force-bearing surface 1582 and the third force-bearing surface 1583 through the channel formed by the upper oil outlet 1511 and the first oil outlet 1521, and applies forces P2•A2 and P3•A3 to the second force-bearing surface 1582 (the effective area of ​​the second force-bearing surface 1582 is A2) and the third force-bearing surface 1583 (the effective area of ​​the third force-bearing surface 1583 is A3) respectively. According to Pascal's principle, the hydraulic pressure of the hydraulic oil on the three force-bearing surfaces is equal, that is, P1=P2=P3.

[0047] As the pressure increases, the above balance equation only needs to adjust the three force-bearing surface areas of the pilot valve 158, because the areas of the three force-bearing surfaces are not equal, and the effective force-bearing area (equal to A1+A2, A3) is always positive. Therefore, the effective area is constant, so the maximum thrust of the pilot valve 158 is only affected by the pilot valve spring 159. As the pilot valve spring 159 is compressed, the force of the pilot valve spring 159 becomes greater and greater, and the pressure becomes greater. When the effective thrust formed by the hydraulic pressure pushes the pilot valve 158 to move and disengages from the mating surface at the smallest diameter of the first valve port 1526, the high-pressure hydraulic oil can exert a force on the upper surface of the first cone valve 156. Due to the action of the first cone valve spring 157 (the stiffness coefficient of the first cone valve spring 157 is required to be greater than the stiffness coefficient of the pilot valve spring 159, and the first cone valve spring 157 has a memory function spring that recovers slowly, and because the shock block 140 occupies a certain distance, the space of the upper hydraulic chamber 400 cannot be 0, that is, the hydraulic oil in the upper hydraulic chamber 400 will not all enter the lower hydraulic chamber 500. , so the residual hydraulic oil can slow down the rapid resetting of the first cone valve 156 to close the first valve port 1526), ​​the hydraulic oil in the upper hydraulic chamber 400 continues to be pressurized, and when the effective hydraulic thrust received by the pilot valve 158 is sufficient to overcome the spring force of the first cone valve spring 157 so that the line contact of the first cone valve 156 is disengaged, at this time, the upper hydraulic chamber 400 and the lower hydraulic chamber 500 are fully connected, and the hydraulic oil in the upper hydraulic chamber 400 is depressurized. Since the drill string stores energy during the hydraulic oil pressure holding period, the drill string releases energy after the hydraulic oil is depressurized, and the shock block 140 moves upward rapidly with the drill pipe core shaft 110, and quickly impacts the sealing joint 120, and transmits the impact vibration to the entire drill string to vibrate and unblock the stuck drill string.

[0048] How this tool works

[0049] The upper hydraulic chamber 400 and the lower hydraulic chamber 500 are filled with hydraulic oil. In order not to affect normal drilling and cause sudden pressure build-up and impact, the hydraulic oil in the upper hydraulic chamber 400 and the lower hydraulic chamber 500 should not be completely filled, and a certain amount of space should be left.

[0050] When the drill string is stuck, the drill pipe mandrel 110 drives the two-way hydraulically controlled one-way valve 150 to move upward. When the reserved space in the upper hydraulic chamber 400 is compensated by the moving distance, the hydraulic oil in the upper hydraulic chamber 400 begins to accumulate pressure. When the pressure relief condition is reached, the pressure can be released to release the energy impact of the drill string, which has a vibration and decompression effect on the drill string.

[0051] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Any simple modification or equivalent changes made to the above embodiments based on the technical essence of the present invention shall fall within the protection scope of the present invention.

Claims

1. A hydraulic unblocking and anti-pressure tool, characterized in that: The invention comprises a drill pipe mandrel (110), a plugging joint (120), a hydraulic cylinder (130), a shock block (140), a two-way hydraulically controlled one-way valve (150), a buffer piston (160) and a retaining ring (170); a first step (131) and a second step (132) are arranged inside the hydraulic cylinder (130); the plugging joint (120) is connected to the hydraulic cylinder (130); the drill pipe mandrel (110) is slidably connected to the plugging joint (120); and the shock block (140) is circumferentially fixedly mounted on the drill pipe mandrel (110). The hydraulic cylinder (130) is provided with a hydraulic control device (140) and a hydraulic control device (120). The hydraulic control device (140) is provided with a hydraulic control device (12 ...) and a hydraulic control device (120) are provided. The hydraulic control device (140) is provided with a hydraulic control device (120) and a hydraulic control device (120) and a hydraulic control device (120) are provided. The hydraulic control device (140) is provided with a hydraulic control device (120) and a hydraulic control device (120) are provided. The hydraulic control device (140) is provided with a hydraulic control device (120) and a hydraulic control device (120) are provided. The hydraulic control device (140) is provided with a hydraulic control device (120) and a hydraulic control device (120) are provided. The hydraulic control device (140) is provided with 2. A hydraulic jam-releasing and anti-pressure tool according to claim 1, characterized in that: The bidirectional hydraulically controlled one-way valve (150) comprises an upper valve cover (151), a valve body (152), a lower valve cover (153), a first cone valve seat (154), a pilot valve seat (155), a first cone valve (156), a first cone valve spring (157), a pilot valve (158) and a pilot valve spring (159), wherein the upper valve cover (151), the valve body (152) and the lower valve cover (153) are arranged in sequence, and the first cone valve seat (154), the first cone valve spring (157), the first cone valve (156), the pilot valve spring (159) and the pilot valve spring (159) are arranged in sequence. 59), the pilot valve seat (155) and the pilot valve (158) are sequentially arranged to form a reverse hydraulically controlled one-way valve (800); the pilot valve (158), the pilot valve seat (155), the pilot valve spring (159), the first cone valve (156), the first cone valve spring (157) and the first cone valve seat (154) are sequentially arranged to form a forward hydraulically controlled one-way valve (900); the reverse hydraulically controlled one-way valve (800) and the forward hydraulically controlled one-way valve (900) are arranged on the upper valve cover (151), the valve body (152) and the lower valve cover (153).

3. A hydraulic jam-releasing and anti-pressure tool according to claim 2, characterized in that: The upper valve cover (151) is provided with an upper oil outlet (1511), an upper hydraulic control port (1512), an upper oil inlet (1513), an upper pilot valve hole (1514), an upper cone valve hole (1515) and a first flow channel (1516), wherein the first flow channel (1516) is in communication with a port of the upper pilot valve (158).

4. A hydraulic jam-releasing and anti-pressure tool according to claim 3, characterized in that: The valve body (152) is provided with a first oil outlet (1521), a second oil outlet (1522), a middle pilot valve hole (1523), a middle cone valve hole (1524), a second flow channel (1525) and a first valve port (1526); the second flow channel (1525) is communicated with the middle cone valve hole (1524); the first oil outlet (1521) and the second oil outlet (1522) are respectively communicated with the bottom surfaces of the middle pilot valve hole (1523) on both end surfaces of the valve body (152).

5. A hydraulic jam-releasing and anti-pressure tool according to claim 4, characterized in that: The lower valve cover (153) is provided with a lower oil outlet (1531), a lower hydraulic control port (1532), a lower oil inlet (1533), a lower pilot valve hole (1534), a lower cone valve hole (1535) and a third flow channel (1536), and the third flow channel (1536) is communicated with the lower pilot valve hole (1534).

6. A hydraulic jam-releasing and anti-pressure tool according to claim 5, characterized in that: The pilot valve (158) is provided with a first force-bearing surface (1581), a second force-bearing surface (1582) and a third force-bearing surface (1583). The pilot valve (158) is installed in a hole formed by an upper pilot valve hole (1514) and a middle pilot valve hole (1523); or the pilot valve (158) is installed in a hole formed by a lower pilot valve hole (1534) and a middle pilot valve hole (1523). The pilot valve spring (159) is arranged between the second force-bearing surface (1582) and the third force-bearing surface (1583). When the pilot valve (158) is installed between the upper valve cover (151) and the valve body, When the pilot valve (158) is installed in the mounting hole formed on the lower valve cover (153) and the valve body (152), the first force-bearing surface (1581) should be flush with the first flow channel (1516) when not subjected to the hydraulic pressure, ensuring that the hydraulic oil can enter without resistance; when the pilot valve (158) is installed in the mounting hole formed on the lower valve cover (153) and the valve body (152), the first force-bearing surface (1581) should be flush with the third flow channel (1536) when not subjected to the hydraulic pressure, ensuring that the hydraulic oil can enter without resistance. After the pilot valve (158) is installed, the pilot valve seat (155) should be threadedly connected to the valve cover for limiting.

7. A hydraulic jam-releasing and anti-pressure tool according to claim 6, characterized in that: The first cone valve (156) is installed in a hole formed by a middle cone valve hole (1524) on the valve body (152) and an upper cone valve hole (1515) on the upper valve cover (151); or the first cone valve (156) is installed in a hole formed by a lower cone valve hole (1535) on the lower valve cover (153), and the first cone valve (156) is in close contact with a large end of the first valve port (1526) via a first cone valve spring (157).

8. The hydraulic jam-releasing and anti-pressure tool according to claim 7, characterized in that: The upper valve cover (151), the valve body (152) and the lower valve cover (153) are respectively provided with an upper threaded hole (1517), a middle threaded hole (1527) and a lower threaded hole (1537); the upper valve cover (151), the valve body (152) and the lower valve cover (153) are connected via the upper threaded hole (1517), the middle threaded hole (1527), the lower threaded hole (1537) and bolts.

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