A type of pipe insertion for finding blocked water pipes

Abstract

This invention relates to a tubing string for locating water plugs, comprising a drop-out outer tube and an inner tube. The drop-out outer tube includes an upper packer, a lower packer, an upper oil inlet channel, a middle oil inlet channel, and a lower oil inlet channel. The inner tube includes a tubing. The drop-out outer tube also includes an upper seal and a lower seal located on the upper and lower sides of the upper packer, respectively. Each of the upper and lower seals contains a sealing element. The tubing has sealing mating sections on the upper and lower sides of the fluid inlet of the inner tube: an upper sealing mating section and a lower sealing mating section. These sealing mating sections are used to seal with the sealing elements in the upper and lower seals when the inner tube is raised and lowered. The tubing string for locating water plugs provided by this invention eliminates the need for a sealing assembly on the outer periphery of the inner tube, preventing damage to the external rubber seals from friction with the wellbore wall during the well running process. This improves the reliability of the seal and reduces the number of rubber seals required, thus saving costs.

Description

Technical Field

[0001] This invention relates to the field of water plugging technology in oilfield mechanical extraction, specifically to a tubing string for water plugging. Background Technology

[0002] During oilfield development, especially in the later stages of water injection development, the overall water cut gradually increases, and the inter-layer contradictions become increasingly prominent. In order to understand the oil layers and stabilize oil production while controlling water, "insertion tubing strings for finding and plugging water" are frequently used for water-finding operations. Existing technology for insertion tubing strings for finding and plugging water can be found in the patent document CN 210919029 U, which discloses a "water-finding tubing string for three-layer oil production." This water-finding tubing string includes an outer tube and an inner tube. The outer tube has a central channel for inserting the inner tube. The outer tube includes two packers distributed vertically: an upper packer and a lower packer. These two packers divide the outer tube into upper, middle, and lower sections, simultaneously separating three oil-producing layers: the upper oil-producing layer, the middle oil-producing layer, and the lower oil-producing layer. Each section of the outer tube has an inlet channel connecting each oil-producing layer to the central channel. The inner tube includes a sealed insertion tube distributed vertically: No. 1... The sealing tubes consist of four types: No. 4 sealing tube, an inner tube with a central channel containing an oil pump, and a screen tube located between No. 2 and No. 3 sealing tubes. The screen tube's through-hole forms an inner tube inlet communicating with the central channel. An outer sealing cylinder (upper and lower) is located within the central channel and engages with the sealing tubes. Specifically, a sealing assembly containing a sealing ring is located on the outer circumference of the sealing tubes, and the outer sealing cylinder has an inner circumferential surface for sealing with the sealing ring. In use, raising and lowering the inner tubes changes the position of the screen tube within the central channel and the corresponding sealing engagement between the sealing tube and the outer sealing cylinder. This allows for the exploitation of designated oil-producing layers (upper, middle, and lower oil-producing layers) and the sealing of designated oil-producing layers (upper, middle, and lower oil-producing layers).

[0003] As can be seen from the above, in the existing tubing string for finding and plugging water, the four sealing tubes on the inner tube cooperate with the two outer sealing cylinders on the outer tube to achieve the sealing and separation of the oil layers on the upper and lower sides of the packer. However, in actual work, it has been found that the sealing rings on the outer periphery of the four sealing tubes are easily damaged by friction with the well wall during the inner tube's running into the well, which leads to the failure of finding and plugging water. Summary of the Invention

[0004] The purpose of this invention is to provide a tubing string for finding and plugging water, so as to solve the problem that the sealing assembly on the inner tube of the tubing string for finding and plugging water in the prior art is damaged by friction with the well wall during the well running process, resulting in failure to find and plug water.

[0005] This invention provides a tubing string for locating blockages, comprising an outer tube and an inner tube. The outer tube has a central channel for inserting the inner tube. The outer tube includes an upper packer, a lower packer, an upper oil inlet channel, a middle oil inlet channel, and a lower oil inlet channel. The inner tube includes an insert tube with a central channel and an inner tube inlet port communicating with the central channel. The outer tube further includes an upper seal and a lower seal located on the upper and lower sides of the upper packer, respectively. The upper and lower seals each have a sealing element: an upper sealing element and a lower sealing element. The lower sealing element is located below the middle oil inlet channel. The upper oil inlet channel is located below the upper seal. Above the component, the lower oil inlet channel is located below the lower seal, and the middle oil inlet channel is located between the upper and lower seals; the insert has sealing mating sections on the upper and lower sides of the inner tube inlet hole: upper sealing mating section and lower sealing mating section; the sealing mating sections are used to seal with the seals in the upper and lower seals when the inner tube is lifted and lowered, thereby achieving: (a) the inner tube inlet hole is located below the lower seal and produces oil in the lower oil layer; (b) the inner tube inlet hole is located above the seal inlet hole and below the upper seal of the upper seal and produces oil in the middle oil layer; (c) the inner tube inlet hole is located above the upper seal and produces oil in the upper oil layer.

[0006] The water-finding and plugging tubing string provided by this invention features two packers connected in series on the outer tube, allowing for sealing of both packers in a single tubing run. The inner tube lacks a sealing assembly on its outer periphery, preventing damage to the external rubber seals from friction with the wellbore wall during downhole operation. This improves sealing reliability and reduces the number of rubber seals required, saving costs. This invention reliably locates and plugs water in three oil layers, boasting a high success rate and long service life.

[0007] Furthermore, the cannula is composed of a first cannula, a connector, and a second cannula connected from bottom to top.

[0008] Furthermore, the lower end of the first insertion tube is provided with a cone, and the liquid inlet of the inner tube is opened on the second insertion tube.

[0009] Furthermore, the sealing section is formed by smooth outer walls with equal outer diameters on the upper and lower sides of the liquid inlet hole of the inner tube.

[0010] Furthermore, the sealing element is an annular sealing element, and the upper sealing element and the lower sealing element are upper annular sealing elements and lower annular sealing elements, respectively. The sealing mating section of the insertion tube and the annular sealing elements in the upper and lower sealing elements achieve sealing through circumferential sealing mating.

[0011] Furthermore, the upper sealer includes an inner hole, and an upper annular seal is disposed in the inner hole; a guide sleeve is provided in the inner hole of the upper sealer above the upper annular seal, and an upper guide section, a guide cone surface, and a lower guide section are provided on the inner circumferential surface of the guide sleeve. The inner diameter of the upper guide section is larger than that of the lower guide section, and the inner diameter of the lower guide section is larger than that of the upper annular seal. The guide cone surface is larger at the top and smaller at the bottom, and is used to guide the inner tube entering the guide sleeve toward the center.

[0012] Furthermore, the upper annular seal includes an annular bracket and a rubber sealing ring, with the rubber sealing ring disposed on the inner circumferential surface of the annular bracket; the rubber sealing ring is bonded to the annular groove on the inner circumferential surface of the annular bracket by vulcanization, wherein the annular bracket is a vulcanized steel component and the rubber sealing ring is a vulcanized rubber component.

[0013] Furthermore, the oil inlet channel is a seal inlet hole located on the lower seal and above the lower annular seal.

[0014] Furthermore, the lower seal includes an inner hole, and a lower annular seal is disposed within the inner hole. A sealing sleeve, positioned above the lower annular seal and capable of vertical movement, is installed within the inner hole of the lower seal. The sealing sleeve moves vertically to have an upper position that closes the liquid inlet of the seal and a lower position that opens the liquid inlet. Shear pin holes are correspondingly provided on the upper part of the sealing sleeve and the upper part of the lower seal. The upper sealing sleeve is fixed to the upper part of the lower seal by shear pins. Corresponding holes are provided on the outer wall of the lower part of the sealing sleeve and the inner wall of the middle part of the lower seal. The corresponding snap ring and snap ring groove are used. The lower sealing sleeve and the middle part of the lower seal are fixed together by the snap ring and snap ring groove. The inner wall of the sealing sleeve is provided with an inwardly protruding shear pin. The shear pin is used to be pushed by the downward moving insertion tube, so that the shear pin and the sealing sleeve are subjected to downward force. The force limit value of the shear pin is less than the force limit value of the shear pin. Therefore, the shear pin and the shear pin fail one after the other when the insertion tube pushes the shear pin downward. After the shear pin fails, the sealing sleeve will move from the upper position to the lower position. After the sealing sleeve moves to the lower position, the shear pin fails, so that the insertion tube can continue to descend.

[0015] Furthermore, the lower annular seal includes an annular base and a sealing ring. The sealing ring is disposed on the inner circumferential surface of the annular base, and the sealing ring is bonded to the annular groove on the inner circumferential surface of the annular base by vulcanization. The annular base is a vulcanized steel component, and the sealing ring is a vulcanized rubber component. Attached Figure Description

[0016] Figure 1 This is a schematic diagram illustrating the usage state of an embodiment of the pipe insertion and blockage locating water pipe column of the present invention;

[0017] Figure 2 yes Figure 1 A schematic diagram of the cannula structure in the middle;

[0018] Figure 3 yes Figure 1 A schematic diagram of the upper seal in the middle;

[0019] Figure 4 yes Figure 1 A schematic diagram of the lower seal in the middle;

[0020] In the picture:

[0021] 1. Oil pump; 2. Anchor; 3. Insert tube; 31. Inner tube inlet; 32. First insert tube; 33. Cone; 34. Connecting joint; 35. Second insert tube; 4. Release device; 5. Upper seal; 51. Upper connector; 511. Inner flange; 52. Guide sleeve; 521. Upper guide section; 522. Lower guide section; 523. Guide cone surface; 524. Outer flange; 53. Annular bracket; 531. Outer sealing ring groove; 54. Rubber sealing ring; 55. Lower connector; 6. Upper 7. Packer; 71. Lower sealer; 72. Sealer inlet; 73. Upper connector; 74. Middle connector; 75. Lower connector; 76. Shear pin; 77. Sealing sleeve; 78. Shear pin; 79. Snap ring; 80. Annular base; 81. Sealing ring; 8. Safety joint; 9. Lower packer; 10. Sealing ball seat; 11. Screen tube; 12. Plug; 100. Casing; 101. Upper oil production layer; 102. Middle oil production layer; 103. Lower oil production layer. Detailed Implementation

[0022] An embodiment of the present invention for inserting a tube to locate a blocked water pipe, such as... Figures 1-4 As shown, it includes an outer casing and an inner casing. The outer casing is used to fix the casing 100 of the oil well. The outer casing has a central channel for inserting the inner casing. The inner casing is used to be inserted into the outer casing.

[0023] The drop-out outer casing includes two packers distributed vertically: an upper packer 6 and a lower packer 9. The upper packer 6 and lower packer 9 are connected in series via a connecting pipe. The two packers are sealed to the casing 100, thus dividing the drop-out outer casing into upper, middle, and lower sections from the outside. Simultaneously, it separates the oil-producing layers into three corresponding layers: upper oil-producing layer 101, middle oil-producing layer 102, and lower oil-producing layer 103. Each section of the drop-out outer casing is equipped with an oil inlet channel: an upper oil inlet channel, a middle oil inlet channel, and a lower oil inlet channel. Each oil inlet channel connects the corresponding oil-producing layer of each section of the drop-out outer casing to the central channel. The drop-out outer casing also includes a drop-out device 4 (in accordance with existing technology), a safety joint 8, a seated ball seat 10, a screen pipe 11, and a plug 12.

[0024] The outer tube also includes a seal for sealing with the insertion tube 3: an upper seal 5 and a lower seal 7. Each seal contains an annular seal: an upper annular seal installed in the upper seal 5 and a lower annular seal installed in the lower seal 7. The upper seal 5 and lower seal 7 are located on the upper and lower sides of the upper packer 6, respectively. The upper oil inlet channel is located above the upper seal 5, and the lower oil inlet channel is located below the lower seal 7. In this embodiment, the middle oil inlet channel is a seal inlet hole 71 located on the lower seal 7 and above the lower annular seal, meaning the middle oil inlet channel is located between the upper and lower annular seals. In other words, the upper annular seal of the upper seal 5 and the lower annular seal of the lower seal 7 internally divide the outer tube into three sections: upper, middle, and lower. The aforementioned oil inlet channels (upper oil inlet channel, middle oil inlet channel, and lower oil inlet channel) are located on the sections divided by the upper seal 5 and the lower seal 7, respectively.

[0025] The inner tube has a central channel, which serves as an oil extraction channel. An oil pump 1 is installed in the central channel. The inner tube includes an anchor 2 and an insert 3 located at the lower end of the inner tube. The bottom end of the insert 3 is closed, and the insert 3 has an inner tube inlet hole 31 that communicates with the central channel.

[0026] Intubation 3 Figure 2 As shown, the insertion tube 3 is a hollow tube. Sealing sections formed by smooth outer walls of equal outer diameter are provided on both the upper and lower sides of the inner tube inlet hole 31 of the insertion tube 3. These sealing sections include an upper sealing section and a lower sealing section. The sealing sections of the insertion tube 3 achieve a seal by circumferentially sealing the annular seals in the upper sealer 5 and the lower sealer 7. When the inner tube is raised and lowered, the sealing sections engage with the annular seals in the upper sealer 5 and the lower sealer 7 (the annular seals are divided into an upper annular seal installed in the upper sealer 5 and a lower annular seal installed in the lower sealer 7) to seal and separate the corresponding oil-bearing layers on both sides of the packer of the corresponding outer tube. In this embodiment, the insertion tube 3 is formed by connecting the first insertion tube 32, the connecting section 34, and the second insertion tube 35 from bottom to top. The lower end of the first insertion tube 32 is provided with a cone head 33, and the inner tube inlet hole 31 is opened on the second insertion tube 35.

[0027] Upper seal 5 Figure 3As shown, the device includes an upper connector 51 and a lower connector 55. Both upper connectors 51 and lower connectors 55 are hollow tubular, forming an inner hole within the upper sealer 5. This inner hole serves as part of the central channel in the outer tube and can be penetrated by the insertion tube 3. The upper end of the upper connector 51 has an internal thread for connection with the connecting tube, and the lower end of the lower connector 55 has an external thread for connection with the connecting tube. The lower end of the upper connector 51 and the upper end of the lower connector 55 are connected by threads. The lower end of the upper connector 51 has an internal thread, and the upper end of the lower connector 55 has an external thread. The upper end of the lower connector 55 is inserted into the lower end of the upper connector 51 to achieve a threaded fit. A guide sleeve 52 is provided in the inner hole of the upper sealer, and an upper annular seal is disposed in the inner hole of the upper sealer, with the guide sleeve 52 positioned above the upper annular seal.

[0028] The guide sleeve 52 and the upper annular seal are both located within the lower connector 55. The outer circumferential surface of the guide sleeve 52 is provided with an outer retaining edge 524, and the interior of the upper connector 51 is provided with an inwardly protruding inner retaining edge 511. The outer retaining edge 524 is clamped between the lower end face of the inner retaining edge 511 of the upper connector 51 and the upper end face of the lower connector 55, thus fixing the guide sleeve 52. The inner circumferential surface of the inner retaining edge 511 of the upper connector 51 is provided with a chamfer that slopes from top to bottom and from the outside inward. The chamfer is located above the inner circumferential surface of the guide sleeve 52. The chamfer is used to guide and straighten the inner tube before it enters the guide sleeve 52, facilitating the entry of the inner tube into the guide sleeve 52.

[0029] The inner circumferential surface of the guide sleeve 52 is provided with an upper guide section 521, a guide cone surface 523, and a lower guide section 522 distributed vertically. The inner diameter of the upper guide section 521 is larger than that of the lower guide section 522, and the inner diameter of the lower guide section 522 is larger than that of the upper annular seal. The guide cone surface 523 is larger at the top and smaller at the bottom, and is used to straighten and guide the inner tube entering the guide sleeve 52 towards the center, which facilitates the inner tube entering the upper annular seal.

[0030] The upper annular seal includes an annular bracket 53 and a rubber sealing ring 54. The rubber sealing ring 54 is disposed on the inner circumferential surface of the annular bracket 53. In this embodiment, the rubber sealing ring 54 is bonded to the annular groove on the inner circumferential surface of the annular bracket 53 by vulcanization. Thus, the annular bracket 53 is a vulcanized steel part, and the rubber sealing ring 54 is a vulcanized rubber. The rubber sealing ring 54 is tightly adhered to the inner circumferential surface of the annular bracket 53. When the insertion tube 3 is lifted or lowered, under the condition of a pressure difference between the upper and lower sides of the rubber sealing ring 54, the rubber sealing ring 54 is not easily detached or damaged, thus extending its service life. The outer circumferential surface of the annular bracket 53 is provided with an outer sealing ring groove 531, in which a sealing ring that seals with the inner circumferential surface of the lower connector 55 is installed.

[0031] The working principle of the upper sealer 5 is as follows: When the insertion tube 3 is inserted into the upper sealer 5, the insertion tube 3 passes through the upper connector 51 and the guide sleeve 52 and enters the upper annular seal. After the sealing mating section of the insertion tube 3 contacts the rubber sealing ring 54 of the upper annular seal, a seal is achieved, which separates the upper and lower sides of the upper annular seal inside the upper sealer 5 into two sealing pressure systems. When the insertion tube 3 is pulled out of the upper sealer 5, the upper sealer 5 becomes a single pressure system.

[0032] Lower seal 7 Figure 4 As shown, it includes an upper connector 72, a middle connector 73, and a lower connector 74 distributed vertically. All three connectors are hollow tubes, forming an inner hole within the lower sealer 7. This inner hole serves as part of the central channel in the outer tube and can be penetrated by the insertion tube 3. A sealing sleeve 76 and a lower annular seal are installed within the inner hole of the lower sealer.

[0033] The upper and lower ends of the middle connector 73 are threaded to the upper connector 72 and the lower connector 74 respectively. The upper connector 72 is provided with a seal inlet hole 71. The upper end of the upper connector 72 is provided with an internal thread for connecting to the connecting pipe. The lower end of the lower connector 74 is provided with an external thread for connecting to the connecting pipe.

[0034] The sealing sleeve 76 is installed in the upper middle part of the inner hole of the lower sealer, located in the upper connector 72 and the middle connector 73. The sealing sleeve 76 can move up and down to have an upper position that closes the liquid inlet hole 71 of the sealer and a lower position that opens the liquid inlet hole 71 of the sealer. The upper part of the sealing sleeve 76 and the upper connector 72 are respectively provided with shear pin holes. The upper sealing sleeve 76 is fixed to the upper connector 72 by shear pin 75. The lower outer wall of the sealing sleeve 76 and the inner wall of the middle connector 73 are respectively provided with corresponding snap rings 78 and snap ring grooves 79. The lower sealing sleeve 76 and the middle connector 73 are respectively provided with corresponding snap rings 78 and snap ring grooves 79. 3. The sealing sleeve 76 is fixed together by the engagement of the snap ring 78 and the snap ring groove 79. The inner wall of the sealing sleeve 76 is provided with an inwardly protruding shear pin 77. The shear pin 77 is used to push the downward-moving insertion tube 3, so that the shear pin 77 and the sealing sleeve 76 are subjected to downward force. The force limit value of the shearing pin 75 is less than the force limit value of the shear pin 77. Therefore, the shearing pin 75 and the shear pin 77 fail sequentially when the insertion tube 3 pushes the shear pin 77 downward. After the shearing pin 75 fails, the sealing sleeve 76 will move from the upper position to the lower position. After the sealing sleeve 76 moves to the lower position, the shear pin 77 fails, allowing the insertion tube 3 to continue to descend. The function of the sealing sleeve 76 is: the sealing sleeve 76 is fixed to the lower seal 7 by the shearing pin 75. The lower seal 7 is in a sealed state before the insertion tube 3 is inserted, and there is no communication between the inside and outside. This ensures that after the release string is lowered to the position, the hydraulic seat is used to seal the packer 6 and the lower packer 9.

[0035] The lower annular seal is installed in the lower connector 74. The lower annular seal includes an annular base 80 and a sealing ring 81. The sealing ring 81 is located on the inner circumferential surface of the annular base 80. In this embodiment, the sealing ring 81 is bonded to the annular groove on the inner circumferential surface of the annular base 80 by vulcanization. Thus, the annular base 80 is a vulcanized steel part, and the sealing ring 81 is a vulcanized rubber. The sealing ring 81 is tightly adhered to the inner circumferential surface of the annular base 80. When the insertion tube 3 is lifted or lowered, under the condition of a pressure difference between the upper and lower sides of the sealing ring 81, the sealing ring 81 is not easily dislodged or damaged, thus extending its service life. The outer circumferential surface of the annular base 80 is provided with a sealing ring that seals with the inner circumferential surface of the lower connector 74.

[0036] The working principle of the lower annular seal is as follows: When the insert tube 3 is inserted into the lower sealer 7, the insert tube 3 enters the upper connector 72 and contacts the shear pin 77 and is pressurized. First, the shear pin 75 is cut off, and the pressure continues to be applied. The sealing sleeve 76 moves downward with the insert tube 3, opening the liquid inlet hole 71 of the sealer. Liquid can flow in and out through the liquid inlet hole 71 of the sealer, realizing internal and external communication. The sealing sleeve 76 continues to move downward with the insert tube 3. The retaining ring 78 enters the retaining ring groove 79, which fixes the sealing sleeve 76. The pressure continues to be applied, cutting off the shear pin 77. The insert tube 3 continues to move downward and enters the lower annular sealer. After the sealing mating section of the outer wall of the insert tube 3 contacts the rubber sealing ring 81 of the lower annular sealer, a seal is achieved. The upper and lower sides of the lower annular sealer inside the lower sealer 7 are sealed into two sealing pressure systems. At the same time, the upper part of the lower sealer 7 is connected internally and externally through the liquid inlet hole 71 of the sealer. When the insert tube 3 is pulled out of the lower sealer 7, the lower sealer 7 becomes a single pressure system.

[0037] When the above-described embodiment of the pipe insertion method for finding blocked water pipes of the present invention is used, after the insertion pipe 3 is inserted into the upper sealer 5 and the lower sealer 7, it has the following operating modes:

[0038] (a) The inner tube inlet hole 31 is located below the lower annular seal of the lower sealer 7. The inner tube inlet hole 31 is connected to the lower oil inlet channel to produce oil from the lower oil production layer 103.

[0039] (b) The inner tube inlet hole 31 is located above the sealer inlet hole 71 and below the upper annular seal of the upper sealer 5. The inner tube inlet hole 31 is connected to the middle oil inlet channel to produce oil from the middle oil production layer 102.

[0040] (c) The inner tube inlet hole 31 is located above the upper annular seal of the upper sealer 5. The inner tube inlet hole 31 is connected to the upper oil inlet channel to produce oil from the upper oil production layer 101.

[0041] In addition, in the above embodiments, the upper packer on the outer tube is a Y445 water-blocking packer, and the lower packer is a Y341 water-blocking packer. In other embodiments of the present invention, the two packers can also be replaced with other common combinations as needed. Furthermore, in other embodiments of the present invention, the three-section tube in the above embodiments can also be a two-section structure. Furthermore, in other embodiments of the present invention, the lower sealer has a sealer inlet hole as a middle oil inlet channel. In other embodiments, the middle oil inlet channel can also be located on the connecting pipe or the extension pipe connected to the packer, instead of having a sealer inlet hole in the lower sealer. Embodiments formed by simple substitutions or obvious modifications listed above or similar are also embodiments of the technical solution of the present invention.

Claims

1. A plug-in water pipe string, comprising a release outer tube and an inner tube inserted into the central channel of the release outer tube, the release outer tube including upper and lower packers and upper, middle, and lower oil inlet channels, the inner tube including a plug tube, the plug tube having an inner tube inlet hole communicating with the central channel of the inner tube, characterized in that, The outer tube also includes upper and lower seals located on the upper and lower sides of the upper packer, respectively. The upper and lower seals are equipped with corresponding upper and lower sealing elements, with the lower sealing element located below the middle oil inlet channel. The upper oil inlet channel is located above the upper sealing element, the lower oil inlet channel is located below the lower sealing element, and the middle oil inlet channel is located between the upper and lower sealing elements. The insert has upper and lower sealing mating sections on the upper and lower sides of the inner tube's liquid inlet hole. The sealing mating sections can achieve sealing mating with the upper and lower sealing elements as the inner tube is lifted and lowered: (a) the inner tube's liquid inlet hole is located below the lower sealing element for oil production in the lower oil-producing layer; (b) the inner tube's liquid inlet hole is located above the sealing element's liquid inlet hole and below the upper sealing element for oil production in the middle oil-producing layer; (c) the inner tube's liquid inlet hole position... Oil is extracted from the upper oil-producing layer above the upper seal. A sealing sleeve is installed in the inner hole of the lower seal, above the lower annular seal. The sealing sleeve moves up and down to have an upper / lower position to close / open the liquid inlet of the seal. The upper sealing sleeve is fixed to the upper part of the lower seal by a shear pin, and the lower sealing sleeve is fixed to the middle part of the lower seal by a snap ring and a snap ring groove. The inner wall of the sealing sleeve is provided with inwardly protruding shear pins. The downward-moving insertion tube can push and cause the shear pins and sealing sleeve to be subjected to downward force. The force limit value of the shear pin is less than the force limit value of the shear pin. After the shear pin fails, the sealing sleeve will move from the upper position to the lower position. After the sealing sleeve moves to the lower position, the shear pin fails and the insertion tube can continue to descend.

2. The pipe string for finding and blocking water as described in claim 1, characterized in that, The cannula (3) is formed by connecting the first cannula (32), the connecting section (34), and the second cannula (35) from bottom to top.

3. The pipe string for finding and blocking water as described in claim 2, characterized in that, The lower end of the first insertion tube (32) is provided with a cone (33), and the liquid inlet (31) of the inner tube is opened on the second insertion tube (35).

4. The pipe string for finding and blocking water as described in claim 1, characterized in that, The sealing section is formed by smooth outer walls with equal outer diameters on the upper and lower sides of the inner tube inlet hole (31) of the insertion tube (3).

5. The tubing string for finding and blocking water supply according to any one of claims 1-4, characterized in that, The sealing element is an annular sealing element. The upper sealing element and the lower sealing element are an upper annular sealing element and a lower annular sealing element, respectively. The sealing section of the insertion tube (3) and the annular sealing elements in the upper sealing device (5) and the lower sealing device (7) achieve sealing through circumferential sealing cooperation.

6. The tubing string for finding and blocking water as described in claim 5, characterized in that, The upper seal (5) includes an inner hole of the upper seal, and an upper annular seal is disposed in the inner hole of the upper seal; a guide sleeve (52) is provided in the inner hole of the upper seal, which is above the upper annular seal. The inner circumferential surface of the guide sleeve (52) is provided with an upper guide section (521), a guide cone surface (523), and a lower guide section (522) distributed vertically. The inner diameter of the upper guide section (521) is larger than that of the lower guide section (522), and the inner diameter of the lower guide section (522) is larger than that of the upper annular seal. The guide cone surface (523) is larger at the top and smaller at the bottom and is used to guide the inner tube entering the guide sleeve (52) towards the center.

7. The pipe string for finding and blocking water as described in claim 6, characterized in that, The upper annular seal includes an annular bracket (53) and a rubber sealing ring (54). The rubber sealing ring (54) is disposed on the inner circumferential surface of the annular bracket (53). The rubber sealing ring (54) is combined with the annular groove on the inner circumferential surface of the annular bracket (53) by vulcanization. The annular bracket (53) is a vulcanized steel part, and the rubber sealing ring (54) is a vulcanized rubber.

8. The pipe string for finding and blocking water as described in claim 5, characterized in that, The oil inlet channel is the seal inlet hole (71) located on the lower seal (7) and above the lower annular seal.

9. The pipe string for finding and blocking water as described in claim 8, characterized in that, The lower annular seal is disposed in the inner hole of the lower sealer.

10. The pipe string for finding and blocking water as described in claim 8, characterized in that, The lower annular seal includes an annular base (80) and a sealing ring (81). The sealing ring (81) is located on the inner circumferential surface of the annular base (80). The sealing ring (81) is bonded to the annular groove on the inner circumferential surface of the annular base (80) by vulcanization. The annular base (80) is a vulcanized steel part, and the sealing ring (81) is a vulcanized rubber.

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