CN220151317U - Pipe string for locating and plugging water through pipe insertion - Google Patents

Abstract

The utility model relates to a cannula water plugging finding pipe column, which comprises a releasing outer pipe and an inner pipe, wherein the releasing outer pipe comprises the following components: the inner pipe comprises a cannula, the release outer pipe further comprises an upper sealer and a lower sealer which are respectively arranged on the upper side and the lower side of the upper packer, and sealing elements are respectively arranged in the upper sealer and the lower sealer: an upper seal member, a lower seal member; the upper and lower both sides of intubate in inner tube feed liquor hole are provided with sealed cooperation section: an upper seal mating segment, a lower seal mating segment; the seal engagement section is for sealing engagement with the seals in the upper and lower sealers as the inner tube is lifted and lowered. The plugging pipe column provided by the utility model has the advantages that the sealing assembly is not arranged on the periphery of the inner pipe, so that the damage caused by friction between the rubber seal outside the sealing assembly and the wall of a shaft in the well descending process is avoided, the sealing reliability is improved, the number of rubber seals is reduced, and the cost is saved.

Description

Pipe string for locating and plugging water through pipe insertion

Technical Field

The utility model relates to the technical field of oil field mechanical exploitation water shutoff finding, in particular to a pipe insertion water shutoff finding pipe column.

Background

In the development process of oil fields, particularly in the later stage of water injection development, comprehensive water content rises gradually, and the contradiction between layers is more and more prominent, so that in order to know an oil layer, oil stabilization and water control are carried out, a 'cannula is often used for finding and plugging a water pipe column'. The cannula in the prior art can be seen in the 'three-layer oil extraction is with looking for water shutoff pipe column' disclosed in patent document with the authority bulletin number of CN 210919029U, this looks for water shutoff pipe column includes release outer tube and inner tube, is equipped with the central channel that supplies inner tube male in the release outer tube, and the release outer tube includes two packers that distribute from top to bottom: the upper packer and the lower packer are used for dividing the release outer pipe into an upper section, a middle section and a lower section and separating three oil recovery layers simultaneously: the upper oil recovery layer, the middle oil recovery layer and the lower oil recovery layer are respectively provided with an oil inlet channel which is communicated with each oil recovery layer and the central channel on each section of the releasing outer pipe, and the inner pipe comprises sealing insertion pipes which are distributed up and down: the inner tube is provided with a central channel, an oil pump is arranged in the central channel, the inner tube further comprises a sieve tube positioned between the second sealing cannula and the third sealing cannula, a sieve tube through hole on the sieve tube forms an inner tube liquid inlet hole communicated with the central channel on the inner tube, and an outer sealing tube which is positioned in the central channel and is matched with the sealing cannula is arranged in the releasing outer tube: the upper outer sealing cylinder and the lower outer sealing cylinder, in particular, the outer periphery of the sealing insertion tube is provided with a sealing assembly comprising a sealing ring, and the outer sealing cylinder is provided with an inner peripheral surface for sealing fit with the sealing ring. When the inner pipe is used, the inner pipe is lifted up and lowered down, the oil recovery layer of appointed exploitation in the upper oil recovery layer, the middle oil recovery layer and the lower oil recovery layer can be exploited by changing the position of the sieve pipe in the central channel and the sealing fit formed by the insertion of the corresponding sealing insertion pipe and the outer sealing cylinder, and the oil recovery layer of appointed blocking in the upper oil recovery layer, the middle oil recovery layer and the lower oil recovery layer can be blocked.

From the above, in the prior art, the four sealing cannulas on the inner pipe are matched with the two outer sealing barrels on the releasing outer pipe to realize the plugging separation of each oil layer on the upper side and the lower side of the packer, and in actual work, the sealing rings on the peripheries of the four sealing cannulas are easily rubbed with the shaft wall to be damaged in the inner pipe down-hole process, so that the problem of water searching and plugging failure is caused.

Disclosure of Invention

The utility model aims to provide a pipe insertion water finding and blocking pipe column, which aims to solve the problems that a sealing assembly on an inner pipe of the pipe insertion water finding and blocking pipe column in the prior art is damaged due to friction with a shaft wall in the well descending process, so that water finding and blocking fails.

The utility model relates to a cannula plugging finding pipe column, which comprises a releasing outer pipe and an inner pipe, wherein a central channel for inserting the inner pipe is arranged in the releasing outer pipe, and the releasing outer pipe comprises: the inner pipe comprises an insertion pipe, a central channel is arranged in the inner pipe, and an inner pipe liquid inlet hole communicated with the central channel is formed in the insertion pipe. The upper sealing piece and the lower sealing piece are positioned below the middle oil inlet channel; the upper oil inlet channel is positioned above the upper sealing piece, the lower oil inlet channel is positioned below the lower sealing piece, and the middle oil inlet channel is positioned between the upper sealing piece and the lower sealing piece; the upper and lower both sides of intubate in inner tube feed liquor hole are provided with sealed cooperation section: an upper seal mating segment, a lower seal mating segment; the seal matching section is used for being matched with the sealing elements in the upper sealer and the lower sealer in a sealing way when the inner pipe is lifted up and lowered down, so that the sealing matching section is realized: (a) The inner pipe liquid inlet is positioned below the lower sealing element to recover oil from the lower oil recovery layer; (b) The inner pipe liquid inlet is positioned above the sealer liquid inlet and below the upper sealing element of the upper sealer to recover oil in the middle oil recovery layer; (c) The inner pipe liquid inlet is positioned above the upper sealing element to recover oil from the upper oil recovery layer.

According to the pipe insertion water plugging pipe column, the two packers of the releasing outer pipe are connected in series, the two packers can be set by one pipe column, and the periphery of the inner pipe is not provided with the sealing assembly, so that the damage caused by friction between the rubber seal outside the sealing assembly and the wall of a shaft in the well descending process is avoided, the sealing reliability is improved, the number of rubber seal sets is reduced, and the cost is saved. The utility model can reliably find and block water for three oil layers, and has high construction success rate and long effective period.

Furthermore, the insertion tube is formed by connecting a first insertion tube, a connector and a second insertion tube from bottom to top.

Further, the lower end of the first cannula is provided with a conical head, and the inner tube liquid inlet hole is formed in the second cannula.

Further, the sealing matching section is formed by smooth outer walls with equal outer diameters, wherein the smooth outer walls are arranged on the upper side and the lower side of the liquid inlet hole of the inner tube through the insertion tube.

Furthermore, 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, and the sealing matching section of the insertion tube is matched with the annular sealing elements in the upper sealing element and the lower sealing element through circumferential sealing to realize sealing.

Further, the upper sealer comprises an upper sealer inner bore in which an upper annular seal is disposed; the inner hole of the upper sealer is internally provided with a guide sleeve above the upper annular sealing element, the inner peripheral surface of the guide sleeve is provided with an upper guide section, a guide conical surface and a lower guide section which are distributed up and down, the inner diameter of the upper guide section is larger than that of the lower guide section, the inner diameter of the lower guide section is larger than that of the upper annular sealing element, and the guide conical surface is large and small up and down and is used for centering and guiding an inner pipe entering the guide sleeve.

Further, the upper annular sealing piece comprises an annular bracket and a rubber sealing ring, and the rubber sealing ring is arranged on the inner peripheral surface of the annular bracket; the rubber sealing ring is combined with the annular groove on the inner peripheral surface of the annular support in a vulcanization mode, the annular support is a vulcanized steel part, and the rubber sealing ring is vulcanized rubber.

Further, the middle oil inlet channel is a sealer liquid inlet hole arranged on the lower sealer and positioned above the lower annular sealing piece.

Further, the lower sealer comprises a lower sealer inner bore in which a lower annular seal is disposed; the sealing sleeve which is positioned above the lower annular sealing piece and can move up and down is arranged in the inner hole of the lower sealer, the sealing sleeve moves up and down and is provided with an upper position for sealing the liquid inlet of the sealer and a lower position for opening the liquid inlet of the sealer, the upper part of the sealing sleeve and the upper part of the lower sealer are correspondingly provided with shear pin holes, the sealing sleeve which is positioned at the upper position is fixed with the upper part of the lower sealer through shear pins, the inner walls of the upper part of the outer wall of the lower part of the sealing sleeve and the middle part of the lower sealer are respectively provided with corresponding snap springs and snap spring grooves, the sealing sleeve which is positioned at the lower position is fixed with the middle part of the lower sealer through the clamping fit of the snap springs and the snap spring grooves, the inner wall of the sealing sleeve is provided with inwardly protruding shear nails, the shear nails are used for being pushed by the insertion pipes which move down to enable the shear nails and the sealing sleeves to bear downward, and the stress limit value of the shear pins is smaller than the stress limit value of the shear nails, and then: the shear pin and the shear pin are sequentially invalid when the insertion pipe pushes the shear pin downwards, the sealing sleeve moves from the upper position to the lower position after the shear pin is invalid, and the shear pin is invalid after the sealing sleeve moves to the lower position, so that the insertion pipe can continue to descend.

Further, the lower annular sealing piece comprises an annular base and a sealing rubber ring, the sealing rubber ring is arranged on the inner peripheral surface of the annular base, the sealing rubber ring is combined with an annular groove on the inner peripheral surface of the annular base in a vulcanization mode, the annular base is a vulcanized steel piece, and the sealing rubber ring is vulcanized rubber.

Drawings

FIG. 1 is a schematic view of an embodiment of a cannula water shutoff string of the present utility model in use;

FIG. 2 is a schematic view of the cannula of FIG. 1;

FIG. 3 is a schematic view of the upper sealer of FIG. 1;

FIG. 4 is a schematic view of the lower sealer of FIG. 1;

in the figure:

1. an oil pump; 2. an anchor; 3. a cannula; 31. an inner pipe liquid inlet hole; 32. a first cannula; 33. a conical head; 34. a connecting joint; 35. a second cannula; 4. a release device; 5. an upper sealer; 51. an upper joint; 511. an inner blocking edge; 52. a guide sleeve; 521. an upper guide section; 522. a lower guide section; 523. a guiding conical surface; 524. an outer stop edge; 53. an annular bracket; 531. an outer seal ring groove; 54. a rubber seal ring; 55. a lower joint; 6. setting a packer; 7. a lower sealer; 71. a sealer liquid inlet; 72. an upper connector; 73. a middle connector; 74. a lower connector; 75. a shear pin; 76. sealing sleeve; 77. shearing nails; 78. clamping springs; 79. a clamp spring groove; 80. an annular base; 81. sealing rubber rings; 8. a safety joint; 9. a lower packer; 10. sealing the ball seat; 11. a screen pipe; 12. plugging; 100. a sleeve; 101. a top oil extraction layer; 102. a medium oil recovery layer; 103. and (5) lower oil production layer.

Detailed Description

An embodiment of a cannula water shutoff pipe column of the utility model, as shown in fig. 1-4, comprises a release outer pipe and an inner pipe, wherein the release outer pipe is used for being fixed in a sleeve 100 of an oil well, a central channel for inserting the inner pipe is arranged in the release outer pipe, and the inner pipe is used for being inserted in the release outer pipe.

The release outer tube comprises two packers distributed up and down: the upper packer 6 and the lower packer 9 are connected in series through connecting pipes, and the two packers are in sealing fit with the sleeve 100, so that the packer divides the outer release pipe into an upper section, a middle section and a lower section from the outside and simultaneously separates oil recovery layers into three oil recovery layers which are in one-to-one correspondence with the sections of the outer release pipe: the upper oil recovery layer 101, the middle oil recovery layer 102 and the lower oil recovery layer 103 are respectively provided with an oil inlet channel on each section of the releasing outer pipe: the oil inlet device comprises an upper oil inlet channel, a middle oil inlet channel and a lower oil inlet channel, wherein each oil inlet channel is respectively used for communicating an oil extraction layer corresponding to each section of the releasing outer pipe with the central channel. The releasing outer tube is also provided with a releasing device 4, a safety joint 8, a seat sealing ball seat 10, a sieve tube 11 and a plug 12 which belong to the prior art.

The outer release tube further comprises a sealer for sealing engagement with the cannula 3: an upper sealer 5 and a lower sealer 7, wherein an annular sealing element is arranged in the sealer: the upper annular seal installed in the upper sealer 5, the lower annular seal installed in the lower sealer 7, the upper sealer 5 and the lower sealer 7 are respectively positioned on the upper side and the lower side of the upper packer 6, the upper oil inlet passage is positioned above the upper sealer 5, the lower oil inlet passage is positioned below the lower sealer 7, in the embodiment, the middle oil inlet passage is a sealer liquid inlet hole 71 which is arranged on the lower sealer 7 and is positioned above the lower annular seal, namely, the middle oil inlet passage is positioned between the upper annular seal and the lower annular seal. That is, the upper annular seal of the upper sealer 5 and the lower annular seal of the lower sealer 7 divide the outer pipe of the release into three upper, middle and lower sections from the inside, and the aforementioned respective oil intake passages (upper oil intake passage, middle oil intake passage, lower oil intake passage) are respectively located on the sections divided by the upper sealer 5 and the lower sealer 7.

The inner pipe is provided with a central channel which is used as an oil pumping channel, the central channel is provided with an oil pump 1, the inner pipe comprises an anchor 2 and a cannula 3 positioned at the lower end part of the inner pipe, the lowest end of the cannula 3 is closed, and the cannula 3 is provided with an inner pipe liquid inlet hole 31 communicated with the central channel.

As shown in fig. 2, the cannula 3 is a hollow tube, the upper and lower sides of the liquid inlet hole 31 of the inner tube are provided with sealing matching sections formed by smooth outer walls with equal outer diameters, the sealing matching sections comprise an upper sealing matching section and a lower sealing matching section, the sealing matching sections of the cannula 3 and annular sealing elements in the upper sealing device 5 and the lower sealing device 7 are sealed through circumferential sealing matching, and the sealing matching sections are used for matching the annular sealing elements in the upper sealing device 5 and the lower sealing device 7 when the inner tube is lifted up and down (the annular sealing elements are divided into an upper annular sealing element arranged in the upper sealing device 5 and a lower annular sealing element arranged in the lower sealing device 7), so as to separate oil extraction layer plugging corresponding to two sides of a packer of the corresponding release outer tube. The cannula 3 in this embodiment is formed by connecting a first cannula 32, a connecting joint 34 and a second cannula 35 from bottom to top, the lower end of the first cannula 32 is provided with a conical head 33, and the inner tube liquid inlet hole 31 is formed on the second cannula 35.

The upper sealer 5, as shown in fig. 3, includes an upper joint 51, a lower joint 55, both of which are hollow tubular in shape to form an upper sealer inner bore in the upper sealer 5 that can be inserted through by the cannula 3 as part of a central passage in the outer tube of the release. The upper joint 51 has an internal thread for connection with a connection pipe at its upper end, and the lower joint 55 has an external thread for connection with a connection pipe at its lower end. The lower end of the upper joint 51 is screwed with the upper end of the lower joint 55, the lower end of the upper joint 51 is provided with internal threads, the upper end of the lower joint 55 is provided with external threads, and the upper end of the lower joint 55 is inserted into the lower end of the upper joint 51 to realize threaded engagement. A guide sleeve 52 is provided in the upper sealer bore, an upper annular seal is provided in the upper sealer bore, and the guide sleeve 52 is located above the upper annular seal.

The guide sleeve 52 and the upper annular sealing member are both positioned in the lower joint 55, an outer baffle edge 524 is arranged on the outer peripheral surface of the guide sleeve 52, an inward convex inner baffle edge 511 is arranged in the upper joint 51, and the outer baffle edge 524 is clamped between the lower end surface of the inner baffle edge 511 of the upper joint 51 and the upper end surface of the lower joint 55 so that the guide sleeve 52 is fixed. The inner peripheral surface of the inner baffle edge 511 of the upper joint 51 is provided with a chamfer which is inclined from top to bottom to the inside, the chamfer is positioned above the inner peripheral surface of the guide sleeve 52, and the chamfer is used for centering and guiding the inner tube before entering the guide sleeve 52, thereby facilitating the inner tube to enter the guide sleeve 52.

The inner peripheral surface of the guide sleeve 52 is provided with an upper guide section 521, a guide conical surface 523 and a lower guide section 522 which are distributed up and down, the inner diameter of the upper guide section 521 is larger than that of the lower guide section 522, the inner diameter of the lower guide section 522 is larger than that of the upper annular sealing element, the guide conical surface 523 is large and small up and down and is used for centering and guiding the inner tube entering the guide sleeve 52, and the inner tube is facilitated to enter the upper annular sealing element.

The upper annular sealing member comprises an annular support 53 and a rubber sealing ring 54, wherein the rubber sealing ring 54 is arranged on the inner peripheral surface of the annular support 53, in the embodiment, the rubber sealing ring 54 is combined with an annular groove on the inner peripheral surface of the annular support 53 in a vulcanization mode, so that the annular support 53 is a vulcanized steel member, the rubber sealing ring 54 is vulcanized rubber, the rubber sealing ring 54 is tightly adhered to the inner peripheral surface of the annular support 53, and when the cannula 3 is lifted or lowered, the rubber sealing ring 54 is not easy to fall off and damage under the condition that pressure difference exists between the upper side and the lower side of the rubber sealing ring 54, so that the effective period is prolonged. The outer peripheral surface of the annular support 53 is provided with an outer seal ring groove 531, and a seal ring which is in sealing fit with the inner peripheral surface of the lower joint 55 is installed in the outer seal ring groove 531.

The upper sealer 5 operates on the principle that: after the cannula 3 is inserted into the upper sealer 5, the cannula 3 passes through the upper joint 51 and the guide sleeve 52 to enter the upper annular sealer, the sealing matching section of the cannula 3 is contacted with the rubber sealing ring 54 of the upper annular sealer to realize sealing, the upper side and the lower side of the upper annular sealer in the upper sealer 5 are sealed into an upper sealing pressure system and a lower sealing pressure system, and after the cannula 3 is pulled out of the upper sealer 5, the upper sealer 5 is changed into a pressure system.

As shown in fig. 4, the lower sealer 7 includes an upper connector 72, a middle connector 73, and a lower connector 74 that are vertically distributed, and the upper connector 72, the middle connector 73, and the lower connector 74 are hollow tubes, and a lower sealer inner hole is formed in the lower sealer 7, and the lower sealer inner hole can be inserted through the cannula 3 as a part of a central passage in the release outer tube. The sealing sleeve 76 and the lower annular sealing element which are distributed up and down are arranged in the inner hole of the lower sealer.

The upper and lower ends of the middle connector 73 are respectively connected with an upper connector 72 and a lower connector 74 in a threaded manner, a sealer liquid inlet 71 is arranged on the upper connector 72, an inner thread for connecting with a connecting pipe is arranged at the upper end of the upper connector 72, and an outer thread for connecting with the connecting pipe is arranged at the lower end of the lower connector 74.

The sealing sleeve 76 is arranged at the middle upper part of the inner hole of the lower sealer and is positioned in the upper connector 72 and the middle connector 73, the sealing sleeve 76 can move up and down and is provided with an upper position for closing the liquid inlet 71 of the sealer and a lower position for opening the liquid inlet 71 of the sealer, a shearing pin hole is correspondingly formed in the upper part of the sealing sleeve 76 and the upper connector 72, the sealing sleeve 76 at the upper position is fixed with the upper connector 72 through the shearing pin 75, corresponding clamping springs 78 and clamping spring grooves 79 are respectively formed in the outer wall of the lower part of the sealing sleeve 76 and the inner wall of the middle connector 73, the sealing sleeve 76 at the lower position and the middle connector 73 are fixed together through the clamping connection of the clamping springs 78 and the clamping spring grooves 79, the inner wall of the sealing sleeve 76 is provided with inward protruding shearing pins 77, the shearing pins 77 are used for being pushed by the downward moving insertion pipe 3 so that the shearing pins 77 and the sealing sleeve 76 are stressed downwards, and the stress limit value of the shearing pins 75 is smaller than that of the shearing pins 77: the shear pin 75 and the shear pin 77 are sequentially disabled when the insertion tube 3 pushes the shear pin 77 downwards, the sealing sleeve 76 moves from the upper position to the lower position after the shear pin 75 is disabled, and the shear pin 77 is disabled after the sealing sleeve 76 moves to the lower position, so that the insertion tube 3 can continue to descend. The function of the sealing sleeve 76 is: the sealing sleeve 76 is fixed with the lower sealer 7 through a shear pin 75, the lower sealer 7 is in a sealing state before the insertion of the cannula 3, the inside and the outside are not communicated, and the hydraulic setting of the upper packer 6 and the lower packer 9 after the releasing string is put down to the position can be ensured.

The lower annular sealing member is installed in the lower connector 74, the lower annular sealing member includes annular base 80 and sealing rubber 81, sealing rubber 81 establishes on annular base 80's the inner peripheral face, in this embodiment, sealing rubber 81 combines through the vulcanization mode with the annular groove on the annular base 80's the inner peripheral face, thereby annular base 80 is the vulcanized steel part, sealing rubber 81 is vulcanized rubber, sealing rubber 81 tightly pastes on annular base 80's the inner peripheral face, when lifting up or when lowering intubate 3, under the pressure differential condition exists in sealing rubber 81's upper and lower both sides, sealing rubber 81 is difficult for droing and damages, the extension validity period. The outer peripheral surface of the annular base 80 is provided with a seal ring in sealing engagement with the inner peripheral surface of the lower connector 74.

The working principle of the lower annular sealing piece is as follows: after the cannula 3 is inserted into the lower sealer 7, the cannula 3 enters the upper connector 72 to be contacted with the shear pin 77 for pressurization, the shear pin 75 is sheared firstly for continuous pressurization, the sealing sleeve 76 descends along with the cannula 3, the sealer liquid inlet 71 is opened, and liquid can flow in and out through the sealer liquid inlet 71, so that internal and external communication is realized. The sealing sleeve 76 continues to descend along with the insertion tube 3, the clamping spring 78 enters the clamping spring groove 79 to enable the sealing sleeve 76 to be fixed, the clamping spring groove 79 is continuously pressurized, the shear pin 77 is cut off, the insertion tube 3 continues to descend, the lower annular sealing member is entered, after the sealing matching section of the outer wall of the insertion tube 3 is in rubber contact with the sealing rubber ring 81 of the lower annular sealing member, sealing is achieved, the upper side and the lower side of the lower annular sealing member in the lower sealing member 7 are sealed into an upper sealing pressure system and a lower sealing pressure system, meanwhile, the upper part of the lower sealing member 7 is communicated with the inside and the outside through the sealing member liquid inlet hole 71, and after the insertion tube 3 is pulled out of the lower sealing member 7, the inside of the lower sealing member 7 is changed into a pressure system.

When the embodiment of the plugging pipe column for the intubation tube is used, after the intubation tube 3 is inserted into the upper sealer 5 and the lower sealer 7, the following working modes exist:

(a) The inner pipe liquid inlet 31 is positioned below the lower annular seal of the lower sealer 7, and the inner pipe liquid inlet 31 communicates with the lower oil inlet passage to recover oil from the lower oil recovery layer 103.

(b) The inner pipe intake 31 is located above the sealer intake 71 and below the upper annular seal of the upper sealer 5, the inner pipe intake 31 communicating with the middle oil intake passage to recover oil from the middle oil recovery layer 102.

(c) The inner pipe liquid inlet hole 31 is positioned above the upper annular sealing element of the upper sealer 5, and the inner pipe liquid inlet hole 31 is communicated with the upper oil inlet channel to recover oil from the upper oil recovery layer 101.

In addition, in the embodiment, the upper packer on the releasing outer pipe is a Y445 water shutoff packer, the lower packer is a Y341 water shutoff packer, and in other embodiments of the utility model, the two packers can be replaced by other common combination forms according to actual needs. In addition, in other embodiments of the present utility model, the cannula of the three-stage structure in the above embodiments may be of a two-stage structure. In addition, in other embodiments of the present utility model, the sealer liquid inlet is provided in the lower sealer as the middle oil inlet passage, and in other embodiments, the middle oil inlet passage may be provided on the connecting pipe or the extension pipe to which the packer is connected, instead of the sealer liquid inlet provided in the lower sealer. The embodiments which are formed by simple alternatives or obvious variants listed above or similar thereto also belong to the embodiments which implement the technical solutions of the utility model.

Claims (10)

1. The utility model provides a water pipe column is looked for to intubate, includes release outer tube and inner tube, is equipped with the central channel that supplies inner tube male in the release outer tube, and the release outer tube includes: go up packer (6), lower packer (9), go up oil feed passageway, well oil feed passageway, lower oil feed passageway, the inner tube includes intubate (3), is equipped with central passageway in the inner tube, be equipped with on intubate (3) with communicating inner tube feed liquor hole (31) of central passageway, its characterized in that, release outer tube still includes upper sealer (5), lower sealer (7) that are in upper and lower both sides of last packer (6) respectively, is equipped with the sealing member in upper sealer (5), the lower sealer (7) respectively: the upper sealing piece and the lower sealing piece are positioned below the middle oil inlet channel; the upper oil inlet channel is positioned above the upper sealing piece, the lower oil inlet channel is positioned below the lower sealing piece, and the middle oil inlet channel is positioned between the upper sealing piece and the lower sealing piece; the upper side and the lower side of the inner tube liquid inlet hole (31) of the insertion tube (3) are provided with sealing matching sections: an upper seal mating segment, a lower seal mating segment; the seal matching section is used for being matched with the sealing elements in the upper sealer (5) and the lower sealer (7) in a sealing way when the inner pipe is lifted up and lowered down, so that the sealing matching section is realized: (a) The inner pipe liquid inlet hole (31) is positioned below the lower sealing element to recover oil from the lower oil recovery layer (103); (b) The inner pipe liquid inlet hole (31) is positioned above the sealer liquid inlet hole (71) and below the upper sealing piece of the upper sealer (5) to recover oil from the middle oil recovery layer (102); (c) The inner pipe liquid inlet (31) is positioned above the upper sealing element to recover oil from the upper oil recovery layer (101).

2. The cannula water finding and plugging tubular column according to claim 1, wherein the cannula (3) is formed by connecting a first cannula (32), a connecting joint (34) and a second cannula (35) from bottom to top.

3. The cannula water finding and plugging tubular column according to claim 2, wherein a conical head (33) is arranged at the lower end of the first cannula (32), and the inner tube liquid inlet hole (31) is formed in the second cannula (35).

4. The cannula water finding and plugging tubular column according to claim 1, wherein the sealing matching section is formed by smooth outer walls with equal outer diameters, wherein the smooth outer walls are arranged on the upper side and the lower side of an inner tube liquid inlet hole (31) of the cannula (3).

5. A cannula water finding and plugging tubular column according to any of claims 1-4, wherein 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, and the sealing matching section of the cannula (3) is matched with the annular sealing elements in the upper sealing element (5) and the lower sealing element (7) through circumferential sealing to realize sealing.

6. A cannula water shutoff string as claimed in claim 5, characterised in that the upper sealer (5) comprises an upper sealer bore in which an upper annular seal is provided; the inner hole of the upper sealer is internally provided with a guide sleeve (52) above the upper annular sealing element, the inner peripheral surface of the guide sleeve (52) is provided with an upper guide section (521), a guide conical surface (523) and a lower guide section (522) which are distributed up and down, the inner diameter of the upper guide section (521) is larger than that of the lower guide section (522), the inner diameter of the lower guide section (522) is larger than that of the upper annular sealing element, and the guide conical surface (523) is large up and down and is used for centering and guiding an inner pipe entering the guide sleeve (52).

7. The cannula water shutoff pipe column of claim 6, wherein the upper annular seal member comprises an annular bracket (53) and a rubber seal ring (54), the rubber seal ring (54) being arranged on the inner peripheral surface of the annular bracket (53); the rubber sealing ring (54) is combined with the annular groove on the inner peripheral surface of the annular support (53) in a vulcanization mode, the annular support (53) is a vulcanized steel piece, and the rubber sealing ring (54) is vulcanized rubber.

8. The cannula water shutoff string of claim 5, wherein the middle oil feed passage is a sealer liquid feed hole (71) provided on the lower sealer (7) above the lower annular seal.

9. A cannula water finding and plugging string according to claim 8, wherein said lower sealer (7) comprises a lower sealer bore in which a lower annular seal is provided; the sealing sleeve (76) which is arranged above the lower annular sealing piece and can move up and down is arranged in the inner hole of the lower sealer, the sealing sleeve (76) moves up and down and is provided with an upper position for sealing the sealer liquid inlet hole (71) and a lower position for opening the sealer liquid inlet hole (71), a shearing pin hole is correspondingly formed in the upper part of the sealing sleeve (76) and the upper part of the lower sealer (7), the sealing sleeve (76) which is arranged at the upper position is fixed with the upper part of the lower sealer (7) through a shearing pin (75), corresponding clamping springs (78) and clamping spring grooves (79) are respectively arranged on the outer wall of the lower part of the sealing sleeve (76) and the inner wall of the middle part of the lower sealer (7), the sealing sleeve (76) which is arranged at the lower position is fixed with the middle part of the lower sealer (7) through the clamping springs (78) and the clamping spring grooves (79), shearing pins (77) which are protruded inwards are arranged on the inner wall of the sealing sleeve (76) are used for being pushed by the shearing pins (3) which are moved downwards, so that the shearing pins (77) and the sealing sleeve (76) are stressed downwards are stressed by the limiting force of the shearing pins (75), and the limiting force of the shearing pins (75) is smaller than the limiting force of the shearing pins (77): the shear pin (75) and the shear pin (77) are sequentially disabled when the insertion tube (3) pushes the shear pin (77) downwards, the sealing sleeve (76) moves from the upper position to the lower position after the shear pin (75) is disabled, and the shear pin (77) is disabled after the sealing sleeve (76) moves to the lower position, so that the insertion tube (3) can continue to move downwards.

10. The cannula water finding and plugging pipe column according to claim 8, wherein the lower annular sealing member comprises an annular base (80) and a sealing rubber ring (81), the sealing rubber ring (81) is arranged on the inner peripheral surface of the annular base (80), the sealing rubber ring (81) is combined with an annular groove on the inner peripheral surface of the annular base (80) in a vulcanization mode, the annular base (80) is a vulcanized steel member, and the sealing rubber ring (81) is vulcanized rubber.