Oil well pipe column structure and using method

Abstract

The invention discloses an oil well pipe column structure and a using method. The technical problem that a plurality of switch sliding sleeves in an oil well pipe column can be opened and closed only by drilling down for multiple times is solved. The oil well pipe column structure comprises a center pipe and a plurality of switch sliding sleeves and further comprises opening short sections, the number of the opening short sections is equal to that of the switch sliding sleeves, and the adjacent opening short sections are connected in series through matched long pipes to form opening tools. The number of the closing short sections is equal to that of the switch sliding sleeves, and the adjacent closing short sections are connected in series through matched long pipes to form a closing tool; wherein the opening short section can control the switch sliding sleeves at the corresponding layers and all the layers below the opening short section to slide downwards so as to realize opening control of the switch sliding sleeves, and the closing short section can control the switch sliding sleeves at the corresponding layers and all the layers below the closing short section to slide upwards so as to realize closing control of the switch sliding sleeves. Opening and closing control over the multiple switch sliding sleeves can be achieved through one-time drilling, the number of times of drilling is reduced, and the operation time efficiency is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of oil and gas field production, and in particular relates to an oil well pipe string structure and a use method thereof. Background Art

[0002] The development of marine oil and gas resources is the hot spot and focus of the current development of the world's marine economy. Marine oil and gas resources not only have large reserves, but modern science and technology have already possessed tremendous capabilities for their development. The marine oil and gas industry has developed into an emerging, high-value-added leading industry in the marine economy.

[0003] In the process of oil production, the switch sleeve is the most widely used downhole tool in the field of segmented and layered production and layered sand control of oil and gas wells. This kind of sleeve needs to be opened and closed with the corresponding service tools. For example, according to the operation requirements, it is necessary to open the production channel of a specific layer and carry out production operations on a specific layer, or selectively close the production channel of a specific layer according to the liquid discharge of the production layer, so as to achieve the purpose of layered production, layered plugging and production.

[0004] At present, the control of sliding sleeve switch in oil well pipe string usually adopts one-to-one mode, that is, one switch tool controls one sliding sleeve switch. When multiple sliding sleeves need to be controlled to switch in sequence, the one-to-one control mode requires multiple drilling, which is too costly and has poor timeliness. At the same time, most of the switch tools in related technologies adopt the pressure-type, that is, the switch tools need to be controlled by pressure, which has many problems and high operation risks, and needs to be improved. Summary of the invention

[0005] In order to solve all or part of the above problems, the purpose of the present invention is to provide an oil well pipe string structure and a method of use, which can reduce the number of drilling times, improve operation time efficiency, and reduce operation risks.

[0006] In a first aspect, the present invention provides an oil well tubular structure, comprising a central pipe and a plurality of switch sleeves, the oil well tubular structure further comprising:

[0007] The opening short sections are equal in number to the switch sleeves, and the adjacent opening short sections are connected in series through matching long pipes to form an opening tool;

[0008] The number of closing short sections is equal to that of the switch sleeves, and the adjacent closing short sections are connected in series through matching long pipes to form a closing tool;

[0009] Among them, each of the opening short sections can control the switch sleeve at the corresponding layer and all the layers below it to slide downward to achieve opening control of the switch sleeve, and each of the closing short sections can control the switch sleeve at the corresponding layer and all the layers below it to slide upward to achieve closing control of the switch sleeve.

[0010] Optionally, each of the upper ends of the inner side wall of the switch sleeve is integrally connected with an annular closing key, and each of the lower ends of the inner side wall of the switch sleeve is integrally connected with an annular opening key, the widths of the closing keys and the opening keys on the multiple switch sleeves decrease successively, and each of the opening short sections can cooperate with the opening keys of the corresponding layer and all the layers below it, and each of the closing short sections can cooperate with the closing keys of the corresponding layer and all the layers below it.

[0011] Optionally, each of the opening short section and the closing short section comprises:

[0012] A control cylinder is arranged vertically and is used to be lowered into the central tube;

[0013] An upper joint is arranged at the top of the control tube and is used to connect with a service pipe string or a matching pipe;

[0014] A lower joint, which is arranged at the bottom end of the control cylinder and is used to connect with the matching long pipe;

[0015] A plurality of control plates, each of which is movably disposed on the control cylinder. The plurality of control plates are arranged at equal intervals along the circumference of the control cylinder, and the control plates can slide along the radial direction of the control cylinder;

[0016] A plurality of control keys, each integrally formed and connected to a side of the corresponding control panel away from the control cylinder;

[0017] Each of the opening short sections further comprises a plurality of opening grooves, which are respectively arranged on the corresponding control keys, the widths of the opening grooves on the plurality of opening short sections decrease in sequence, and each of the opening keys can be inserted into the opening grooves of the corresponding layer and all layers below it;

[0018] Each of the closing short sections further comprises a plurality of closing grooves, which are respectively arranged on the corresponding control keys, the widths of the closing grooves on the plurality of closing short sections decrease in sequence, and each of the closing keys can be inserted into the closing grooves of the corresponding layer and all layers below it;

[0019] Each of the opening short section and the closing short section also includes a tube control, which is used to control the corresponding multiple control plates to move synchronously along the radial direction of the control cylinder, so that the multiple closing keys are respectively inserted into the corresponding closing grooves, or the multiple closing keys are respectively removed from the corresponding closing grooves, or the multiple opening keys are respectively inserted into the corresponding opening grooves, or the multiple opening keys are respectively removed from the corresponding opening grooves.

[0020] Optionally, each of the tube controls comprises:

[0021] Control springs, which are provided in a plurality of groups and correspond to the plurality of control plates one by one, and are used to push the corresponding control plates to move in a direction away from the control cylinder;

[0022] An upper control slope, disposed at the upper end of the closing key;

[0023] A lower control slope, arranged at the lower end of the opening key;

[0024] An upper control slope is provided at the upper end of the control key;

[0025] A lower control slope is provided at the lower end of the control key;

[0026] A lower guiding inclined surface is arranged on the inner wall of the bottom side of the opening groove;

[0027] An upper guiding inclined surface is arranged on the top inner wall of the closing groove;

[0028] A support ring, integrally formed and connected to the inner wall of the central tube, the support ring is located below the switch sleeve, and an extrusion slope is provided at the upper end of the support ring;

[0029] A release ring, arranged on the inner side wall of the central tube, and the release ring is located above the switch sliding sleeve;

[0030] A plurality of support blocks are respectively arranged on the inner side wall of the release ring, the plurality of support blocks are arranged at equal intervals along the circumference of the release ring, and each support block is respectively provided with an upper pressing inclined surface at its upper end and a lower pressing inclined surface at its lower end;

[0031] Among them, the upper pressing slope, the upper control slope, the lower control slope, the upper guide slope and the extrusion slope have the same inclination direction, and the lower pressing slope, the upper control slope, the lower guide slope and the lower control slope have the same inclination direction.

[0032] Optionally, an upper claw is disposed at the top of each switch sleeve, a lower claw is disposed at the bottom, a limit claw is disposed at the bottom of each release ring, a limit clamp ring is disposed below each switch sleeve, and the limit clamp ring is integrally connected to the center tube;

[0033] When the switch sleeve moves downward and reaches the open position, the lower clamping claw and the limit clamping ring form an elastic clamping fit, and the locking force between the lower clamping claw and the limit clamping ring is greater than the friction force between the opening short section and the switch sleeve;

[0034] When the switch sleeve moves upward and reaches the closed position, the upper clamping claw and the limit clamping claw form an elastic clamping fit, and the locking force between the upper clamping claw and the limit clamping claw is greater than the friction force between the closing short section and the switch sleeve.

[0035] Optionally, a limit ring is respectively provided at the bottom end of the upper joint and the top end of the lower joint, and an annular sliding gap exists between the limit ring and the control cylinder, the two ends of the control plate are respectively located in the corresponding sliding gaps, and the two ends of the control plate can slide radially along the control cylinder in the corresponding sliding gaps.

[0036] Optionally, a group of guide grooves are respectively provided on one side of each control plate facing the control cylinder, and one end of each group of control springs is respectively inserted into the corresponding guide groove, and the other end is respectively connected to the control cylinder.

[0037] In a second aspect, the present invention provides a method for using an oil well tubular structure, comprising the following steps:

[0038] S1, according to the layer position of the switch sleeve, select an appropriate opening short section or closing short section, and connect adjacent opening short sections or closing short sections in series through matching long pipes to form an opening tool or a closing tool;

[0039] S2, connecting the opening tool or the closing tool to the service string, and lowering the opening tool or the closing tool into the central pipe through the service string;

[0040] S3, by lifting and lowering the service pipe string, use the opening tool to control the switch sleeve to open, or use the closing tool to control the switch sleeve to close.

[0041] Optionally, if you need to control the opening of the switch sleeves of all or some layers:

[0042] Select opening short sections that match the switch sleeves of the corresponding layers respectively, and connect the adjacent opening short sections in series through the matching long pipes to form an opening tool, and ensure that after the opening tool is lowered into the central pipe, the multiple opening short sections are aligned one by one with the switch sleeves of the corresponding layers respectively, connect the opening tool to the service pipe string, and carry the opening tool into the central pipe through the service pipe string. At this time, the multiple opening grooves are respectively engaged with the opening keys of the corresponding layers, and the service pipe string is lowered to make the switch sleeves of all layers or some layers move downward synchronously, so that the switch sleeves of all layers or some layers are opened synchronously;

[0043] Alternatively, only select an opening short section that is compatible with the switch sliding sleeve located at the highest layer among the switch sliding sleeves to be opened, and connect the opening short section with the matching length pipe to form an opening tool, and then connect the opening tool to the service pipe string, and carry the opening tool into the central pipe through the service pipe string. During the process of lowering the service pipe string, the opening grooves are engaged with the opening keys of the corresponding layers from top to bottom and then separated, so that the switch sliding sleeves of all layers or some layers move downward in turn, so that the switch sliding sleeves of all layers or some layers are opened in turn.

[0044] Optionally, if you need to control the switch sleeves of all layers or some layers to close:

[0045] Select closing short sections that match the switch sleeves of the corresponding layers respectively, and connect the adjacent closing short sections in series through the matching long pipes to form a closing tool, and ensure that after the closing tool is lowered into the central pipe, the multiple closing short sections are aligned with the switch sleeves of the corresponding layers one by one, connect the closing tool to the service string, and carry the closing tool into the central pipe through the service string. At this time, the multiple closing grooves are respectively engaged with the closing keys of the corresponding layers, and the service string is lifted to make the switch sleeves of all layers or some layers move upward synchronously, so that the switch sleeves of all layers or some layers are closed synchronously;

[0046] Alternatively, only a closing short section that is compatible with the switch sleeve at the highest level among the switch sleeves to be closed is selected, and the closing short section is connected to the matching length pipe to form a closing tool, and then the closing tool is connected to the service string, and the closing tool is carried into the central pipe through the service string. During the process of lifting the service string, the closing grooves are engaged with the closing keys of the corresponding levels from bottom to top and then separated, so that the switch sleeves of all levels or some levels move upward in turn, so that the switch sleeves of all levels or some levels are closed in turn.

[0047] Optionally, if you need to control the opening of the switch sleeves of some layers:

[0048] Select opening short sections that match the switch sleeves of the corresponding layers respectively, and connect the adjacent opening short sections in series through matching long pipes to form an opening tool, connect the opening tool to the service string, and carry the opening tool through the service string and run it into the central pipe;

[0049] The length of the distribution pipe is set so that there is a distance difference between two adjacent opening short sections, and multiple opening short sections can be aligned with the switch sliding sleeves of the corresponding layers in sequence from the high layer to the low layer, or multiple opening short sections can be aligned with the switch sliding sleeves of the corresponding layers in sequence from the low layer to the high layer;

[0050] When controlling multiple switch sleeves to be opened sequentially from a high level to a low level, first control the opening short section at the high level to cooperate with the switch sleeve at the corresponding level, lower the service string to make the switch sleeve at the high level move downward and open, continue to lower the service string, the opening short section at the second high level to cooperate with the switch sleeve at the corresponding level, lower the service string to make the switch sleeve at the second high level move downward and open, repeat this process, so that the switch sleeves at multiple levels are opened sequentially from a high level to a low level;

[0051] When controlling multiple switch sleeves to be opened in sequence from a low layer to a high layer, first control the opening short section at the low layer to cooperate with the switch sleeve at the corresponding layer, lower the service string to make the switch sleeve at the low layer move downward and open, continue to lower the service string, and the opening short section at the second lowest layer to cooperate with the switch sleeve at the corresponding layer, lower the service string to make the switch sleeve at the second lowest layer move downward and open, and repeat this process, so that the switch sleeves at multiple layers are opened in sequence from a low layer to a high layer.

[0052] Optionally, if you need to control the switch sleeves of some layers to close:

[0053] Select the closing short sections that match the switch sleeves of the corresponding layers respectively, and connect the adjacent closing short sections in series through the matching long pipes to form a closing tool, connect the closing tool to the service string, and carry the closing tool into the central pipe through the service string;

[0054] The length of the distribution pipe is set so that there is a distance difference between two adjacent closing short sections, and a plurality of closing short sections can be aligned with the switch sliding sleeves of the corresponding layers in sequence from the high layer to the low layer, or a plurality of closing short sections can be aligned with the switch sliding sleeves of the corresponding layers in sequence from the low layer to the high layer;

[0055] When controlling multiple switch sleeves to be closed in sequence from a high level to a low level, first control the closing nipple at the high level to cooperate with the switch sleeve at the corresponding level, lift the service string to close the switch sleeve at the high level, then lift the string to move the switch sleeve at the high level upward and close it, continue to lift the string to make the closing nipple at the next high level cooperate with the switch sleeve at the corresponding level, then lift the service string to move the switch sleeve at the next high level upward and close it, and repeat this process, so that the switch sleeves at multiple levels are closed in sequence from a high level to a low level;

[0056] When controlling multiple switch sleeves to be closed in sequence from a low layer to a high layer, first control the closing short section at the low layer to cooperate with the switch sleeve at the corresponding layer, lift the pipe string to make the switch sleeve at the low layer move upward and close, continue to lift the service pipe string, and make the switch sleeve at the second lowest layer cooperate, then lift the service pipe string to make the switch sleeve at the second lowest layer move upward and close, and repeat this process, so that the switch sleeves at multiple layers are closed in sequence from a low layer to a high layer.

[0057] It can be seen from the above technical solutions that the oil well pipe string structure and the use method provided by the present invention have the following advantages:

[0058] The oil well pipe string structure can realize the opening and closing control of multiple switch sleeves in one trip to drill, effectively reducing the number of trips to drill, which can not only reduce the burden on the staff, but also improve the time efficiency of the operation. At the same time, the opening and closing tools are designed as mechanical structures, which are safer and more reliable to operate, thereby reducing the risk of operation.

[0059] Other features and advantages of the present invention will be set forth in the description which follows. BRIEF DESCRIPTION OF THE DRAWINGS

[0060] The accompanying drawings are used to provide a further understanding of the technical solution of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the technical solution of the present invention and do not constitute a limitation on the technical solution of the present invention.

[0061] Figure 1 This is a schematic diagram of the structure of the oil well pipe string in Example 1 of the present invention, mainly showing the state of opening the short joint and lowering the central pipe;

[0062] Figure 2 This is a schematic diagram of the structure of the oil well pipe string in Example 1 of the present invention, mainly showing the state of the closed short joint being lowered into the central pipe;

[0063] Figure 3 It is a cross-sectional view of the opened short section in Example 1 of the present invention;

[0064] Figure 4 It is a cross-sectional view of a closed short section in Example 1 of the present invention;

[0065] Figure 5 It is a schematic diagram of the cooperation between the opening short section and the closing short section and the switch sliding sleeve in Example 1 of the present invention, showing the sizes of the opening slot, closing slot, opening key and closing key at different levels;

[0066] Figure 6 This is a schematic diagram of the matching state of the opening short section and the switch sliding sleeve in Example 1 of the present invention;

[0067] Figure 7 This is a schematic diagram of the matching state of the closing short section and the switch sliding sleeve in Example 1 of the present invention;

[0068] Figure 8 This is a schematic diagram of the state in which the sliding sleeve of the opening short section control switch in Example 1 of the present invention is opened, mainly showing the upper half of the opening short section;

[0069] Fig. 9 This is a schematic diagram of the state in which the sliding sleeve of the opening short section control switch in Example 1 of the present invention is opened, mainly showing the lower half of the opening short section;

[0070] Fig.10 This is a schematic diagram of the state in which the closing short section control switch sliding sleeve is closed in Example 1 of the present invention, mainly showing the upper half of the closing short section;

[0071] Fig.11 This is a schematic diagram of the state in which the closing short section control switch sliding sleeve is closed in Example 1 of the present invention, mainly showing the lower half of the closing short section;

[0072] Fig.12 This is a schematic diagram of the structure of the oil well pipe string in Example 2 of the present invention, mainly showing a schematic diagram of the use status of the opening tool;

[0073] Fig.13 This is a schematic diagram of the structure of the oil well pipe string in Example 2 of the present invention, mainly showing a schematic diagram of the use state of the closing tool;

[0074] Fig.14 This is a schematic diagram of a state in which an opening tool is used to control the synchronous opening of multiple switch sleeves in Embodiment 2 of the present invention;

[0075] Fig.15 This is a schematic diagram of a state in which a plurality of switch sleeves are controlled to be opened in sequence by using an opening tool in Embodiment 2 of the present invention;

[0076] Fig.16 It is a schematic diagram of a state in which a closing tool is used to control the synchronous closing of multiple switch sleeves in Embodiment 2 of the present invention;

[0077] Fig.17 This is a schematic diagram of a state in which a closing tool is used to control multiple switch sleeves to close in sequence in Embodiment 2 of the present invention;

[0078] Fig.18 It is a schematic diagram of the state of using an opening tool to control multiple switch sleeves to be opened layer by layer from a high level to a low level in Example 2 of the present invention;

[0079] Fig.19 It is a schematic diagram of the state of using an opening tool to control multiple switch sleeves to be opened layer by layer from a low level to a high level in Example 2 of the present invention;

[0080] Fig. 20 It is a schematic diagram of the state of using a closing tool to control multiple switch sleeves to close layer by layer from a high level to a low level in Example 2 of the present invention;

[0081] Fig.21 This is a schematic diagram of the state of using a closing tool to control multiple switch sleeves to close layer by layer from a low level to a high level in Example 2 of the present invention.

[0082] Description of reference numerals:

[0083] 1. Center tube; 2. Switch sleeve; 3. Open short section; 4. Close short section; 5. Close key; 6. Open key; 7. Control tube; 8. Upper joint; 9. Lower joint; 10. Control board; 11. Control key; 12. Open slot; 13. Close slot; 14. Tube control; 141. Control spring; 142. Upper control slope; 143. Lower control slope; 144. Upper control slope; 145. Lower control slope; 146. Lower guide slope; 147. Upper guide slope; 148. Support ring; 149. Extrusion slope; 150. Release ring; 151. Support block; 152. Upper pressing slope; 153. Lower pressing slope; 15. Upper claw; 16. Lower claw; 17. Limit claw; 18. Limit clamp ring; 19. Limit ring; 20. Sliding gap; 21. Guide groove;

[0084] 100. Opening tool; 200. Closing tool; 300. Distribution pipe; 400. Service pipe string. DETAILED DESCRIPTION

[0085] To make the purpose, technical solution and advantages of the present invention more clear, the embodiments of the present invention will be described in detail with reference to the accompanying drawings. It should be noted that the embodiments and features in the embodiments of the present invention can be combined with each other arbitrarily without conflict.

[0086] Example 1

[0087] like Figure 1-Figure 11 The embodiment 1 of the present invention is shown, and the embodiment discloses an oil well pipe string structure, including a vertically arranged central pipe 1, a plurality of switch sleeves 2 are vertically slidably connected in the central pipe 1, and the plurality of switch sleeves 2 are arranged in sequence along the vertical direction. The oil well pipe string structure also includes a plurality of opening short sections 3 and a plurality of closing short sections 4, the number of the opening short sections 3 and the closing short sections 4 are respectively equal to the number of the switch sleeves 2, adjacent opening short sections 3 are respectively connected in series through the matching long tubes 300 to form an opening tool 100, and adjacent closing short sections 4 are respectively connected in series through the matching long tubes 300 to form a closing tool 200.

[0088] In one embodiment, Figure 1 , Figure 2 As shown, each opening short section 3 can control the switch sleeve 2 of the corresponding layer and all layers below it to slide downward, so as to realize the opening control of the switch sleeve 2. Each closing short section 4 can control the switch sleeve 2 of the corresponding layer and all layers below it to slide upward, so as to realize the closing control of the switch sleeve 2.

[0089] In one embodiment, Figure 1 , Figure 2As shown, the upper end of the inner side wall of each switch sleeve 2 is integrally connected with an annular closing key 5, and the lower end of the inner side wall of each switch sleeve 2 is integrally connected with an annular opening key 6. The widths of the closing keys 5 and the opening keys 6 on the multiple switch sleeves 2 decrease in sequence, that is, the closing key 5 on the switch sleeve 2 at the highest level has the widest width, each opening short section 3 can cooperate with the opening key 6 at the corresponding level and all levels below it, and each closing short section 4 can cooperate with the closing key 5 at the corresponding level and all levels below it.

[0090] In one embodiment, Figure 3 , Figure 4 As shown, each opening sub 3 and closing sub 4 includes a vertically arranged control tube 7, and the control tube 7 is used to be lowered into the central pipe 1. The top of the control tube 7 is integrally connected with an upper joint 8, and the upper joint 8 is used to be connected to the service pipe string 400 or the distribution pipe 300, and the bottom end of the control tube 7 is threadedly sleeved with a lower joint 9, and the lower joint 9 is used to be connected to the distribution pipe 300.

[0091] In one embodiment, Figure 3 , Figure 4 As shown, a plurality of control panels 10 are movably arranged around the control tube 7. The plurality of control panels 10 are arranged at equal intervals along the circumference of the control tube 7, and the control panels 10 can slide radially along the control tube 7. At the same time, a control key 11 is integrally formed and connected to one side of each control panel 10 away from the control tube 7.

[0092] In one embodiment, Figure 3 , Figure 4 As shown, each opening short section 3 also includes a plurality of opening grooves 12, and the plurality of opening grooves 12 are respectively arranged on the corresponding control keys 11, and the widths of the opening grooves 12 on the plurality of opening short sections 3 decrease successively, that is, the width of the opening groove 12 on the opening short section 3 located at the highest layer is the widest, and the opening grooves 12 are provided for the opening keys 6 at the corresponding layer and all layers therebelow to be snap-fitted.

[0093] In one embodiment, Figure 3 , Figure 4 As shown, each closing short section 4 also includes a plurality of closing grooves 13, and the plurality of closing grooves 13 are respectively arranged on the corresponding control keys 11, and the widths of the closing grooves 13 on the plurality of closing short sections 4 decrease successively, that is, the width of the closing groove 13 on the closing short section 4 located at the highest level is the widest, and the closing groove 13 is provided for the closing keys 5 at the corresponding level and all levels therebelow to be snap-fitted.

[0094] In one embodiment, Figure 3 , Figure 4As shown, each opening short section 3 and closing short section 4 also includes a tube control 14, which is arranged between the control board 10 and the control cylinder 7, and the tube control 14 is used to control the corresponding multiple control boards 10 to move synchronously along the radial direction of the control cylinder 7, so that the multiple closing keys 5 are respectively inserted into the corresponding closing grooves 13, or the multiple closing keys 5 are respectively removed from the corresponding closing grooves 13, or the multiple opening keys 6 are respectively inserted into the corresponding opening grooves 12, or the multiple opening keys 6 are respectively removed from the corresponding opening grooves 12.

[0095] The specific explanations of “the opening slot 12 is for the corresponding layer and the opening key 6 of all layers below it to be snapped together” and “the closing slot 13 is for the corresponding layer and the closing key 5 of all layers below it to be snapped together” in this application are as follows:

[0096] like Figure 5 As shown, if there are six layers of switch sleeves 2 in the central tube 1, the opening groove 12 of the opening short section 3 at the first level (highest level) is for the opening key 6 on the switch sleeves 2 at the first level to the sixth level to be snapped in, and the closing groove 13 on the closing short section 4 at the first level (highest level) is for the closing key 5 on the switch sleeves 2 at the first level to the sixth level to be snapped in. The opening groove 12 of the opening short section 3 at the second level is for the opening key 6 on the switch sleeves 2 at the second level to the sixth level to be snapped in, and the closing groove 13 of the closing short section 4 at the second level is for the closing key 5 on the switch sleeves 2 at the second level to the sixth level to be snapped in. By analogy, the opening groove 12 of the opening short section 3 at the sixth level (lowest level) is only for the opening key 6 on the switch sleeve 2 at the sixth level to be snapped in, and the closing groove 13 of the closing short section 4 at the sixth level (lowest level) is only for the closing key 5 on the switch sleeve 2 at the sixth level to be snapped in.

[0097] In one embodiment, Figure 6 , Figure 7 As shown, each tube control unit 14 includes multiple groups of control springs 141, and the multiple groups of control springs 141 are arranged in a one-to-one correspondence with the multiple control plates 10. Each group of control springs 141 is provided with two, and the two control springs 141 are used to jointly push the corresponding control plate 10 to move in a direction away from the control cylinder 7, so that the closing key 5 forms a snap fit with the corresponding closing groove 13, or the opening key 6 forms a snap fit with the corresponding opening groove 12.

[0098] In one embodiment, Figure 3 , Figure 4 , Figure 6 , Figure 7As shown, the upper end of the closing key 5 is provided with an upper control slope 142, the lower end of the opening key 6 is provided with a lower control slope 143, the upper end of the control key 11 is provided with an upper control slope 144, and the lower end is provided with a lower control slope 145, the bottom inner wall of the opening groove 12 is provided with a lower guide slope 146, and the top inner wall of the closing groove 13 is provided with an upper guide slope 147.

[0099] In one embodiment, Figure 6 , Figure 7 , Figure 8 As shown, the inner side wall of the central tube 1 is integrally connected with a support ring 148, the support ring 148 is located below the switch sleeve 2, and the upper end of the support ring 148 is provided with an extrusion slope 149. The inner side wall of the central tube 1 is threadedly connected with a release ring 150, and the release ring 150 is located above the switch sleeve 2. At the same time, the inner side wall of the release ring 150 is integrally connected with a plurality of support blocks 151, the plurality of support blocks 151 are arranged at equal intervals along the circumference of the release ring 150, and each support block 151 is respectively provided with an upper pressing slope 152 at the upper end and a lower pressing slope 153 at the lower end.

[0100] In one embodiment, Figure 6 , Figure 7 , Figure 8 As shown, the upper pressing slope 152, the upper control slope 142, the lower control slope 145, the upper guide slope 147 and the extrusion slope 149 have the same inclination direction, and the lower pressing slope 153, the upper control slope 144, the lower guide slope 146 and the lower control slope 143 have the same inclination direction.

[0101] In one embodiment, Figure 6 , Figure 7 As shown, the top of each switch sleeve 2 is integrally connected with an upper claw 15, and the bottom end is integrally connected with a lower claw 16, the bottom end of each release ring 150 is integrally connected with a limiting claw 17, and a limiting clamp ring 18 is arranged under each switch sleeve 2, and the limiting clamp ring 18 is integrally connected with the center tube 1.

[0102] When the switch sleeve 2 moves downward and reaches the open position, the lower claw 16 can form an elastic snap fit with the limit snap ring 18, and the locking force between the lower claw 16 and the limit snap ring 18 is greater than the friction between the opening short section 3 and the switch sleeve 2 to prevent the switch sleeve 2 from moving upward when the service pipe string 400 is lifted.

[0103] When the switch sleeve 2 moves upward and reaches the closed position, the upper claw 15 can form an elastic engagement with the limit claw 17, and the locking force between the upper claw 15 and the limit claw 17 is greater than the friction between the closing short section 4 and the switch sleeve 2 to prevent the switch sleeve 2 from moving downward when the service pipe string 400 is lowered.

[0104] like Figure 8 , Fig. 9 As shown, when the opening tool 100 moves downward and makes the opening short section 3 reach the position of the switch sleeve 2 at the same layer, the control key 11 moves toward the control cylinder 7 under the action of the lower control slope 145 and the upper pressing slope 152, that is, the control key 11 is retracted. As the opening tool 100 continues to move downward, the control key 11 remains retracted under the action of the lower control slope 145 and the upper control slope 142. When the opening key 6 is aligned with the opening slot 12, the control key 11 is ejected under the action of the control spring 141, so that the opening key 6 and the opening slot 12 form a snap fit. When the opening tool 100 moves downward, the switch sleeve 2 can move downward synchronously and open. At this time, the lower claw 16 and the limit snap ring 18 form a snap fit. As the opening tool 100 continues to move downward, the control key 11 is retracted under the action of the lower control slope 145 and the extrusion slope 149, so that the opening slot 12 is separated from the opening key 6. Therefore, as the opening tool 100 continues to move downward, the opening groove 12 can form a snap fit with the opening key 6 on the switch sleeve 2 of the next layer, that is, the opening short section 3 can control the switch sleeve 2 located at the layer below it to open. At the same time, when the opening short section 3 at the lower layer passes through the switch sleeve 2 at the higher layer, the width of the opening groove 12 on the opening short section 3 is smaller than the width of the opening key 6 on the switch sleeve 2 at the higher layer, that is, the opening key 6 cannot form a snap fit with the opening groove 12, so that the opening short section 3 at the lower layer can smoothly pass through the switch sleeve 2 at the higher layer.

[0105] like Figure 8 , Fig. 9 As shown, during the upward movement of the opening tool 100, the control key 11 is retracted under the action of the upper control slope 144 and the lower control slope 143, and when the opening key 6 is aligned with the opening slot 12, the opening key 6 is inserted into the corresponding opening slot 12. As the opening tool 100 continues to move upward, the control key 11 is retracted under the action of the lower guide slope 146 and the lower control slope 143, so that the opening key 6 is separated from the opening slot 12. As the opening tool 100 continues to move upward, the control key 11 pops open and the closing key 5 is inserted into the opening slot 12, and then the control key 11 is retracted under the action of the lower guide slope 146 and the closing key 5, so that the closing key 5 is separated from the opening slot 12. As the opening tool 100 continues to move upward, the control key 11 is retracted under the action of the upper control slope 144 and the lower pressing slope 153, so that when the opening tool 100 moves upward, it will not affect the switch sleeve 2.

[0106] like Fig.10 , Fig.11As shown, during the downward movement of the closing tool 200, the control key 11 is retracted under the action of the lower control slope 145 and the upper pressing slope 152, the lower control slope 145 and the upper control slope 142, until the closing slot 13 is aligned with the closing key 5, and the control key 11 pops open to form a snap fit between the closing key 5 and the closing slot 13. As the closing tool 200 continues to move downward, the control key 11 is retracted under the action of the upper guide slope 147 and the upper control slope 142, and the closing key 5 is separated from the closing slot 13. After the closing tool 200 continues to move downward, the closing key 5 is snapped into the closing slot 13, and then the control key 11 is retracted again under the action of the upper guide slope 147 and the closing key 5, so that the closing key 5 is separated from the closing slot 13. As the closing tool 200 continues to move downward, the control key 11 is retracted under the action of the lower control slope 145 and the extrusion slope 149, so that the closing joint can smoothly pass through the switch sleeve 2 at the corresponding level. Therefore, when the closing tool 200 moves downward, it will not affect the switch sleeve 2.

[0107] like Fig.10 , Fig.11 As shown, when the closing tool 200 moves upward and makes the closing short section 4 reach the position of the switch sleeve 2 at the same layer, the control key 11 is retracted under the action of the upper control slope 144 and the lower control slope 143. When the closing key 5 is aligned with the opening groove 12, the control key 11 pops up and the closing key 5 is stuck in the opening groove 12. As the closing tool 200 continues to move upward, the control key 11 is retracted under the action of the lower control slope 143. When the closing key 5 is aligned with the closing groove 13, the control key 11 pops up and the closing key 5 is stuck in the closing groove 13. Subsequently, the control key 11 controls the switch sleeve 2 to move upward so that the switch sleeve 2 is closed. At this time, the upper clamping claw 15 and the limit clamping claw 17 form an elastic clamping fit. As the closing tool 200 continues to move upward, the control key 11 is retracted under the action of the lower pressing slope 153 and the upper control slope 144 so that the closing key 5 is separated from the closing groove 13. Therefore, as the closing tool 200 continues to move upward, the closing sub 4 at the lower layer can smoothly pass through the switch sleeve 2 at the higher layer due to the size difference between the closing key 5 and the closing groove 13. Of course, after the closing sub 4 controls the switch sleeve 2 at the same layer to close, the closing tool 200 can be further lowered, and the closing groove 13 on the closing sub 4 is aligned with the closing key 5 on the switch sleeve 2 at the next layer. At this time, the pipe column can be lifted to close the switch sleeve 2 at the next layer.

[0108] In one embodiment, Figure 3 , Figure 4As shown, a limit ring 19 is threadedly sleeved on the lower end of each upper joint 8, and the upper end of each lower joint 9 is also integrally formed with the limit ring 19, and an annular sliding gap 20 exists between each limit ring 19 and the control cylinder 7, and both ends of each control plate 10 are respectively located in the corresponding sliding gap 20 and can slide radially along the control cylinder 7 in the corresponding sliding gap 20.

[0109] In one embodiment, Figure 3 , Figure 4 As shown, each control plate 10 is provided with a group of guide grooves 21 on the side facing the control cylinder 7, and each group of guide grooves 21 is provided with two. One end of each control spring 141 is respectively inserted into the corresponding guide groove 21, and the other end is respectively connected to the control cylinder 7 to play a guiding role for the control spring 141 and ensure that the control spring 141 can be elastically deformed smoothly.

[0110] As can be seen from the above, the oil well pipe string structure can realize the opening and closing control of multiple switch sleeves 2 in one trip to drill, effectively reducing the number of times to drill, which can not only reduce the burden on the staff, but also improve the time efficiency of the operation. At the same time, each layer of the opening short section 3 / closing short section 4 can control the opening / closing of the switch sleeve 2 of the corresponding layer and all layers below it, so that the staff can have more choices and improve the adaptability of use.

[0111] Example 2

[0112] like Figure 12-Figure 21 The embodiment 2 of the present invention is shown, which discloses a method for using an oil well pipe string structure, including the following steps:

[0113] S1, according to the layer position of the switch sleeve 2, select an appropriate opening short section 3 or closing short section 4, and connect adjacent opening short sections 3 or closing short sections 4 in series through a matching long pipe 300 to form an opening tool 100 or a closing tool 200;

[0114] S2, connecting the opening tool 100 or the closing tool 200 to the service string 400, and lowering the opening tool 100 or the closing tool 200 into the central pipe 1 through the service string 400;

[0115] S3, by lifting and lowering the service pipe string 400, the opening tool 100 is used to control the opening of the switch sliding sleeve 2, or the closing tool 200 is used to control the closing of the switch sliding sleeve 2.

[0116] like Fig.12 , Fig.14As shown, if it is necessary to control the synchronous opening of the switch sleeves 2 of all layers or some layers, select the opening short sections 3 that are compatible with the switch sleeves 2 of the corresponding layers respectively, and connect the adjacent opening short sections 3 in series through the matching length pipes 300 to form an opening tool 100, and ensure that after the opening tool 100 is lowered into the central pipe 1, the multiple opening short sections 3 are aligned one by one with the switch sleeves 2 of the corresponding layers respectively, connect the opening tool 100 with the service pipe string 400, and carry the opening tool 100 into the central pipe 1 through the service pipe string 400. At this time, the multiple opening grooves 12 are respectively snap-fitted with the opening keys 6 of the corresponding layers, and the service pipe string 400 is lowered to make the switch sleeves 2 of all layers or some layers move downward synchronously, so that the switch sleeves 2 of all layers or some layers are opened synchronously.

[0117] like Fig.15 As shown, if it is necessary to control the switch sleeves 2 of all layers or some layers to be opened in sequence, only the opening short section 3 that is compatible with the switch sleeve 2 located at the highest layer among the switch sleeves 2 to be opened is selected, and the opening short section 3 is connected to the matching length pipe 300 to form an opening tool 100, and then the opening tool 100 is connected to the service string 400, and the opening tool 100 is carried by the service string 400 into the central pipe 1. During the process of lowering the service string 400, the opening groove 12 is sequentially engaged with the opening key 6 of the corresponding layer from top to bottom and then separated, so that the switch sleeves 2 of all layers or some layers move downward in sequence, so that the switch sleeves 2 of all layers or some layers are opened in sequence.

[0118] like Fig.13 , Fig.16 As shown, if it is necessary to control the synchronous closing of the switch sleeves 2 of all layers or some layers, the closing short sections 4 adapted to the switch sleeves 2 of the corresponding layers are selected respectively, and the adjacent closing short sections 4 are connected in series through the matching length pipe 300 to form a closing tool 200, and it is ensured that after the closing tool 200 is lowered into the central pipe 1, the multiple closing short sections 4 are aligned one by one with the switch sleeves 2 of the corresponding layers, and the closing tool 200 is connected to the service pipe string 400, and the closing tool 200 is carried by the service pipe string 400 and lowered into the central pipe 1. At this time, the multiple closing grooves 13 are respectively snap-fitted with the closing keys 5 of the corresponding layers, and the service pipe string 400 is lifted to make the switch sleeves 2 of all layers or some layers move upward synchronously, so that the switch sleeves 2 of all layers or some layers are synchronously closed.

[0119] like Fig.17As shown, if it is necessary to control the switch sleeves 2 of all layers or some layers to be closed in sequence, only the closing short section 4 that is compatible with the switch sleeve 2 located at the highest layer among the switch sleeves 2 to be closed is selected, and the closing short section 4 is connected to the matching length pipe 300 to form a closing tool 200, and then the closing tool 200 is connected to the service string 400, and the closing tool 200 is carried by the service string 400 into the central pipe 1. In the process of lifting the service string 400, the closing groove 13 is sequentially engaged with the closing key 5 of the corresponding layer from bottom to top and then separated, so that the switch sleeves 2 of all layers or some layers move upward in sequence, so that the switch sleeves 2 of all layers or some layers are closed in sequence.

[0120] like Fig.18 , Fig.19 As shown, if the switch sleeves 2 of some layers need to be controlled to open in sequence:

[0121] Select opening short sections 3 that are compatible with the switch sleeves 2 of the corresponding layers respectively, and connect adjacent opening short sections 3 in series through the matching length pipes 300 to form an opening tool 100, connect the opening tool 100 to the service string 400, and carry the opening tool 100 into the central pipe 1 through the service string 400.

[0122] The length of the extension pipe 300 is set so that there is a distance difference between two adjacent opening short sections 3, and multiple opening short sections 3 can be aligned with the switch sleeves 2 of the corresponding layers in sequence from high layers to low layers, or multiple opening short sections 3 can be aligned with the switch sleeves 2 of the corresponding layers in sequence from low layers to high layers.

[0123] When controlling multiple switch sleeves 2 to be opened sequentially from a high level to a low level, firstly control the opening short section 3 at the high level to cooperate with the switch sleeve 2 at the corresponding level, lower the service string 400 to make the switch sleeve 2 at the high level move downward and open, continue to lower the service string 400, the opening short section 3 at the next high level cooperates with the switch sleeve 2 at the corresponding level, lower the service string 400 to make the switch sleeve 2 at the next high level move downward and open, repeat this process, so that the switch sleeves 2 at multiple levels are opened sequentially from a high level to a low level;

[0124] When controlling multiple switch sleeves 2 to be opened in sequence from a low layer to a high layer, first control the opening short section 3 at the low layer to cooperate with the switch sleeve 2 at the corresponding layer, lower the service string 400 to make the switch sleeve 2 at the low layer move downward and open, continue to lower the service string 400, and the opening short section 3 at the second lowest layer to cooperate with the switch sleeve 2 at the corresponding layer, lower the service string 400 to make the switch sleeve 2 at the second lowest layer move downward and open, and repeat this process, so that the switch sleeves 2 at multiple layers are opened in sequence from a low layer to a high layer.

[0125] Specific examples are as follows:

[0126] If the central pipe 1 has nine layers of switch sleeves 2, and the third, fifth and eighth layers of switch sleeves 2 need to be opened, select opening short sections 3 that are compatible with the third, fifth and eighth layers of switch sleeves 2, and connect adjacent opening short sections 3 through matching length pipes 300 to form an opening tool 100, and then connect the opening tool 100 to the service pipe string 400.

[0127] like Fig.18 As shown, if it is necessary to control the three switch sleeves 2 to be opened in sequence from the high position to the low position:

[0128] The service string 400 is lowered to align the third-layer opening short section 3 with the third-layer switch sleeve 2. At this time, the fifth-layer and eighth-layer opening short sections 3 are respectively located above the switch sleeves 2 at the corresponding layers. Subsequently, the service string 400 is lowered to open the third-layer switch sleeve 2. At this time, the fifth-layer and eighth-layer opening short sections 3 have not reached the switch sleeves 2 at the corresponding layers. The service string 400 is continued to be lowered until the fifth-layer opening short section 3 cooperates with the fifth-layer switch sleeve 2. At this time, the eighth-layer opening short section 3 has not reached the eighth-layer switch sleeve 2. This is repeated so that the three switch sleeves 2 are opened in sequence from the high position to the low position. It should be noted that when the eighth-layer switch sleeve 2 is opened, the third-layer opening short section 3 has not reached the fourth-layer switch sleeve 2, and the fifth-layer opening short section 3 has not reached the sixth-layer switch sleeve 2.

[0129] like Fig.19 As shown, if it is necessary to control the three switch sleeves 2 to be opened in sequence from the low position to the high position:

[0130] The service string 400 is lowered to align the eighth-layer opening short section 3 with the eighth-layer switch sleeve 2. At this time, the third-layer and fifth-layer opening short sections 3 are respectively located above the corresponding layer switch sleeves 2. Subsequently, the service string 400 is lowered to open the eighth-layer switch sleeve 2. The service string 400 is lowered and the fifth-layer opening short section 3 is matched with the fifth-layer switch sleeve 2. At this time, the third-layer opening short section 3 does not reach the third-layer switch sleeve 2. The service string 400 is lowered again to open the fifth-layer switch sleeve 2. This is repeated so that the three switch sleeves 2 are opened in sequence from the lower layer to the higher layer. It should be noted that when the third-layer switch sleeve 2 is opened, the fifth-layer opening short section 3 does not reach the sixth-layer switch sleeve 2, and the eighth-layer opening short section 3 does not reach the ninth-layer switch sleeve 2.

[0131] like Fig. 20 , Fig.21 As shown, if the switch sleeves 2 of some layers need to be controlled to be closed in sequence:

[0132] The closing pup joints 4 matching the switch sleeves 2 of the corresponding layers are selected respectively, and the adjacent closing pup joints 4 are connected in series through the matching length pipes 300 to form a closing tool 200, the closing tool 200 is connected to the service string 400, and the closing tool 200 is carried by the service string 400 and lowered into the central pipe 1.

[0133] The length of the extension pipe 300 is set so that there is a distance difference between two adjacent closing pup joints 4, and multiple closing pup joints 4 can be aligned with the switch sleeves 2 of the corresponding layers in sequence from high layers to low layers, or multiple closing pup joints 4 can be aligned with the switch sleeves 2 of the corresponding layers in sequence from low layers to high layers.

[0134] When controlling multiple switch sleeves 2 to be closed sequentially from a high level to a low level, first control the closing nipple 4 at the high level to cooperate with the switch sleeve 2 at the corresponding level, lift the service string 400 to close the switch sleeve 2 at the high level, then lift the string to move the switch sleeve 2 at the high level upward and close it, continue to lift the string, make the closing nipple 4 at the next high level cooperate with the switch sleeve 2 at the corresponding level, then lift the service string 400 to move the switch sleeve 2 at the next high level upward and close it, repeat this process, so that the switch sleeves 2 at multiple levels are closed sequentially from a high level to a low level;

[0135] When controlling multiple switch sleeves 2 to be closed in sequence from a low layer to a high layer, first control the closing short section 4 at the low layer to cooperate with the switch sleeve 2 at the corresponding layer, lift the pipe string to make the switch sleeve 2 at the low layer move upward and close, continue to lift the service pipe string 400, and make the switch sleeve 2 at the second lowest layer cooperate, then lift the service pipe string 400 to make the switch sleeve 2 at the second lowest layer move upward and close, and repeat this process, so that the switch sleeves 2 at multiple layers are closed in sequence from a low layer to a high layer.

[0136] Specific examples are as follows:

[0137] If the central pipe 1 has nine layers of switch sleeves 2, and the third, fifth and eighth layers of switch sleeves 2 need to be closed, select closing pup joints 4 that are compatible with the third, fifth and eighth layers of switch sleeves 2, and connect adjacent closing pup joints 4 through matching length pipes 300 to form a closing tool 200, and then connect the closing tool 200 to the service pipe string 400.

[0138] like Fig. 20 As shown, if it is necessary to control the three switch sleeves 2 to be opened in sequence from the high position to the low position:

[0139] The service string 400 is lowered to align the third-layer closing pup joint 4 with the third-layer switch sleeve 2. At this time, the fifth-layer and eighth-layer closing pup joints 4 are respectively located below the switch sleeves 2 at the corresponding layers. Subsequently, the service string 400 is lifted to close the third-layer switch sleeve 2. At this time, the fifth-layer and eighth-layer closing pup joints 4 have not reached the switch sleeves 2 at the corresponding layers. The service string 400 is continuously lifted until the fifth-layer closing pup joint 4 cooperates with the fifth-layer switch sleeve 2. At this time, the eighth-layer closing pup joint 4 has not reached the eighth-layer switch sleeve 2. This is repeated to close the three switch sleeves 2 from the high layer to the low layer. It should be noted that when the service string 400 is lowered and the third-layer closing pup joint 4 is aligned with the third-layer switch sleeve 2, the fifth-layer closing pup joint 4 has not reached the sixth-layer switch sleeve 2, and the eighth-layer closing pup joint 4 has not reached the ninth-layer switch sleeve 2.

[0140] like Fig.21 As shown, if it is necessary to control the three switch sleeves 2 to be closed in sequence from the low position to the high position:

[0141] The service string 400 is lowered to align the eighth-layer closing pup joint 4 with the eighth-layer switch sleeve 2. At this time, the third-layer and fifth-layer closing pup joints 4 are respectively located below the switch sleeves 2 at the corresponding layers. Subsequently, the service string 400 is lifted to close the eighth-layer switch sleeve 2. At this time, the third-layer and fifth-layer closing pup joints 4 have not reached the switch sleeves 2 at the corresponding layers. The service string 400 is further lifted to match the fifth-layer closing pup joint 4 with the fifth-layer switch sleeve 2. At this time, the third-layer closing pup joint 4 has not reached the third-layer switch sleeve 2. The service string 400 is lifted again to close the fifth-layer switch sleeve 2. This is repeated to close the three switch sleeves 2 from the lower layer to the higher layer. It should be noted that when the service string 400 is lowered to align the eighth-layer closing pup joint 4 with the eighth-layer switch sleeve 2, the third-layer closing pup joint 4 has not reached the fourth-layer switch sleeve 2, and the fifth-layer closing pup joint 4 has not reached the sixth-layer switch sleeve 2.

[0142] It should be noted that, unless otherwise specified, the technical terms or scientific terms used in the present invention should have the common meanings understood by those skilled in the art to which the present invention belongs.

[0143] In addition, the terms "first", "second", etc. are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. In the description of the present invention, the meaning of "plurality" is more than two, unless otherwise clearly and specifically defined.

[0144] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be included in the scope of the claims and specification of the present invention. In particular, as long as there is no structural conflict, the various technical features mentioned in each embodiment can be combined in any way. The present invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

Claims

1. An oil well pipe string structure, comprising a central pipe (1) and a plurality of switch sleeves (2), characterized in that: The oil well pipe string structure also includes: The opening short sections (3) are equal in number to the switch sleeves (2), and the adjacent opening short sections (3) are connected in series through the matching long tubes (300) to form an opening tool (100); The closing short sections (4) are equal in number to the switch sleeves (2), and the adjacent closing short sections (4) are connected in series through matching long tubes (300) to form a closing tool (200); Each of the opening short sections (3) can control the corresponding layer and all layers below the switch sleeve (2) to slide downward, so as to achieve opening control of the switch sleeve (2), and each of the closing short sections (4) can control the corresponding layer and all layers below the switch sleeve (2) to slide upward, so as to achieve closing control of the switch sleeve (2).

2. The oil well pipe string structure according to claim 1, characterized in that: The upper end of the inner side wall of each switch sleeve (2) is integrally connected with an annular closing key (5), and the lower end of the inner side wall of each switch sleeve (2) is integrally connected with an annular opening key (6). The widths of the closing keys (5) and the opening keys (6) on the multiple switch sleeves (2) decrease in sequence, and each opening short section (3) can cooperate with the opening keys (6) at the corresponding layer and all layers below it, and each closing short section (4) can cooperate with the closing keys (5) at the corresponding layer and all layers below it.

3. The oil well pipe string structure according to claim 2, characterized in that: Each of the opening short section (3) and the closing short section (4) comprises: A control cylinder (7) is arranged vertically and is used to be lowered into the central tube (1); An upper joint (8) is arranged at the top end of the control tube (7) and is used to connect with a service pipe string (400) or a distribution pipe (300); A lower joint (9) is arranged at the bottom end of the control tube (7) and is used to connect with the matching extension tube (300); A plurality of control plates (10) are movably disposed on the control cylinder (7), the plurality of control plates (10) are arranged at equal intervals along the circumference of the control cylinder (7), and the control plates (10) can slide along the radial direction of the control cylinder (7); A plurality of control keys (11) are integrally formed and connected to a side of the corresponding control panel (10) away from the control cylinder (7); Each of the opening short sections (3) further comprises a plurality of opening grooves (12), wherein the plurality of opening grooves (12) are respectively arranged on the corresponding control keys (11), the widths of the opening grooves (12) on the plurality of opening short sections (3) decrease in sequence, and each of the opening keys (6) can be inserted into the opening grooves (12) at the corresponding layer and all layers below it; Each of the closing short sections (4) further comprises a plurality of closing grooves (13), wherein the plurality of closing grooves (13) are respectively arranged on the corresponding control keys (11), the widths of the closing grooves (13) on the plurality of closing short sections (4) decrease in sequence, and each of the closing keys (5) can be inserted into the closing grooves (13) at the corresponding level and all levels below it; Each of the opening short section (3) and the closing short section (4) further comprises a tube control (14), wherein the tube control (14) is used to control the corresponding plurality of control plates (10) to synchronously move along the radial direction of the control cylinder (7), so that the plurality of closing keys (5) are respectively inserted into the corresponding closing grooves (13), or the plurality of closing keys (5) are respectively removed from the corresponding closing grooves (13), or the plurality of opening keys (6) are respectively inserted into the corresponding opening grooves (12), or the plurality of opening keys (6) are respectively removed from the corresponding opening grooves (12).

4. The oil well pipe string structure according to claim 3, characterized in that: Each of the tube controls (14) comprises: Control springs (141), which are provided in a plurality of groups and correspond one to one with the plurality of control plates (10), and the control springs (141) are used to push the corresponding control plates (10) to move in a direction away from the control cylinder (7); An upper control slope (142) is arranged at the upper end of the closing key (5); A lower control slope (143) is arranged at the lower end of the opening key (6); An upper control slope (144) is arranged at the upper end of the control key (11); A lower control slope (145) is arranged at the lower end of the control key (11); A lower guiding inclined surface (146) is arranged on the inner wall of the bottom side of the opening groove (12); An upper guiding inclined surface (147) is arranged on the inner wall of the top side of the closing groove (13); A support ring (148) is integrally formed and connected to the inner wall of the central tube (1); the support ring (148) is located below the switch sleeve (2); and an extrusion slope (149) is provided at the upper end of the support ring (148); A release ring (150) is arranged on the inner side wall of the central tube (1), and the release ring (150) is located above the switch sliding sleeve (2); A plurality of support blocks (151) are respectively arranged on the inner side wall of the release ring (150); the plurality of support blocks (151) are arranged at equal intervals along the circumference of the release ring (150); an upper pressing inclined surface (152) is respectively arranged at the upper end of each support block (151) and a lower pressing inclined surface (153) is respectively arranged at the lower end; The upper pressing slope (152), the upper control slope (142), the lower control slope (145), the upper guide slope (147) and the extrusion slope (149) have the same inclination direction, and the lower pressing slope (153), the upper control slope (144), the lower guide slope (146) and the lower control slope (143) have the same inclination direction.

5. The oil well pipe string structure according to claim 4, characterized in that: The top of each switch sleeve (2) is provided with an upper claw (15) and the bottom is provided with a lower claw (16), the bottom of each release ring (150) is provided with a limit claw (17), and a limit clamping ring (18) is provided below each switch sleeve (2), and the limit clamping ring (18) is integrally formed and connected with the center tube (1); When the switch sleeve (2) moves downward and reaches the open position, the lower clamping claw (16) and the limit clamping ring (18) form an elastic clamping fit, and the locking force between the lower clamping claw (16) and the limit clamping ring (18) is greater than the friction force between the opening short section (3) and the switch sleeve (2); When the switch sleeve (2) moves upward and reaches the closed position, the upper clamping claw (15) and the limit clamping claw (17) form an elastic clamping fit, and the locking force between the upper clamping claw (15) and the limit clamping claw (17) is greater than the friction force between the closing short section (4) and the switch sleeve (2).

6. The oil well pipe string structure according to claim 4, characterized in that: A limit ring (19) is provided at the bottom end of the upper joint (8) and the top end of the lower joint (9), and an annular sliding gap (20) exists between the limit ring (19) and the control cylinder (7). The two ends of the control plate (10) are respectively located in the corresponding sliding gap (20), and the two ends of the control plate (10) can slide radially along the control cylinder (7) in the corresponding sliding gap (20).

7. The oil well pipe string structure according to claim 4, characterized in that: A group of guide grooves (21) are respectively provided on one side of each control plate (10) facing the control cylinder (7); one end of each group of control springs (141) is respectively inserted into the corresponding guide groove (21), and the other end is respectively connected to the control cylinder (7).

8. A method for using the oil well tubular structure according to any one of claims 1 to 7, characterized in that: The steps include: S1, according to the layer position of the switch sleeve (2), select an appropriate opening short section (3) or closing short section (4), and connect adjacent opening short sections (3) or closing short sections (4) in series through a matching long pipe (300) to form an opening tool (100) or a closing tool (200); S2, connecting the opening tool (100) or the closing tool (200) to the service string (400), and lowering the opening tool (100) or the closing tool (200) into the central pipe (1) through the service string (400); S3, by lifting and lowering the service pipe column (400), using the opening tool (100) to control the switch sliding sleeve (2) to open, or using the closing tool (200) to control the switch sliding sleeve (2) to close.

9. The method for using the oil well pipe string structure according to claim 8, characterized in that: If you need to control the switch sleeve (2) of all layers or some layers to open: Select opening short sections (3) that are compatible with the switch sleeves (2) at the corresponding layers respectively, and connect the adjacent opening short sections (3) in series through the matching length pipe (300) to form an opening tool (100), and ensure that after the opening tool (100) is lowered into the central pipe (1), the plurality of opening short sections (3) are aligned one by one with the switch sleeves (2) at the corresponding layers respectively, connect the opening tool (100) with the service pipe string (400), and carry the opening tool (100) through the service pipe string (400) to lower into the central pipe (1). At this time, the plurality of opening grooves (12) respectively form a snap fit with the opening keys (6) at the corresponding layers, and lower the service pipe string (400) so that the switch sleeves (2) at all layers or some layers move downward synchronously, so that the switch sleeves (2) at all layers or some layers are opened synchronously; Alternatively, only an opening short section (3) that is compatible with the switch sleeve (2) located at the highest level among the switch sleeves (2) to be opened is selected, and the opening short section (3) is connected to the matching length pipe (300) to form an opening tool (100), and then the opening tool (100) is connected to the service pipe string (400), and the opening tool (100) is carried by the service pipe string (400) and lowered into the central pipe (1). During the process of lowering the service pipe string (400), the opening groove (12) is sequentially engaged with the opening key (6) of the corresponding level from top to bottom and then separated, so that the switch sleeves (2) of all levels or part of the levels move downward in sequence, so that the switch sleeves (2) of all levels or part of the levels are opened in sequence.

10. The method for using the oil well pipe string structure according to claim 8, characterized in that: If you need to control the switch sleeve (2) of all layers or some layers to close: Select closing short sections (4) that match the switch sleeves (2) of the corresponding layers respectively, and connect the adjacent closing short sections (4) in series through the matching length pipe (300) to form a closing tool (200), and ensure that after the closing tool (200) is lowered into the central pipe (1), the plurality of closing short sections (4) are aligned one by one with the switch sleeves (2) of the corresponding layers respectively, connect the closing tool (200) with the service pipe string (400), and carry the closing tool (200) through the service pipe string (400) to lower into the central pipe (1). At this time, the plurality of closing grooves (13) respectively form a snap fit with the closing keys (5) of the corresponding layers, and lift the service pipe string (400) to make the switch sleeves (2) of all layers or some layers move upward synchronously, so that the switch sleeves (2) of all layers or some layers are closed synchronously; Alternatively, only a closing short section (4) that matches the switch sleeve (2) located at the highest level among the switch sleeves (2) to be closed is selected, and the closing short section (4) is connected to the matching length pipe (300) to form a closing tool (200), and then the closing tool (200) is connected to the service pipe string (400), and the closing tool (200) is carried by the service pipe string (400) and lowered into the central pipe (1). In the process of lifting the service pipe string (400), the closing groove (13) is sequentially engaged with the closing keys (5) of the corresponding levels from bottom to top and then separated, so that the switch sleeves (2) of all levels or part of the levels move upwards in sequence, so that the switch sleeves (2) of all levels or part of the levels are closed in sequence.

11. The method for using the oil well pipe string structure according to claim 8, characterized in that: If it is necessary to control the opening of the switch sleeve (2) at some layers: Selecting opening short sections (3) that are compatible with the switch sleeves (2) of the corresponding layers, and connecting adjacent opening short sections (3) in series through the matching length pipes (300) to form an opening tool (100), connecting the opening tool (100) to the service pipe string (400), and lowering the opening tool (100) into the central pipe (1) through the service pipe string (400); The length of the distribution pipe (300) is set such that there is a distance difference between two adjacent opening short sections (3), and the plurality of opening short sections (3) can be aligned with the switch sliding sleeves (2) at corresponding layers in sequence from a high layer to a low layer, or the plurality of opening short sections (3) can be aligned with the switch sliding sleeves (2) at corresponding layers in sequence from a low layer to a high layer; When controlling a plurality of switch sleeves (2) to be opened sequentially from a high level to a low level, firstly control the opening short section (3) at the high level to cooperate with the switch sleeve (2) at the corresponding level, lower the service pipe string (400) to make the switch sleeve (2) at the high level move downward and open, continue to lower the service pipe string (400), the opening short section (3) at the next high level cooperates with the switch sleeve (2) at the corresponding level, lower the service pipe string (400) to make the switch sleeve (2) at the next high level move downward and open, repeat this process, so that the switch sleeves (2) at the multiple levels are opened sequentially from a high level to a low level; When controlling a plurality of switch sleeves (2) to be opened sequentially from a low layer to a high layer, firstly control the opening short section (3) of the low layer to cooperate with the switch sleeve (2) of the corresponding layer, lower the service pipe string (400) to make the switch sleeve (2) of the low layer move downward and open, continue to lower the service pipe string (400), the opening short section (3) of the second lowest layer to cooperate with the switch sleeve (2) of the corresponding layer, lower the service pipe string (400) to make the switch sleeve (2) of the second lowest layer move downward and open, repeat this process, so that the switch sleeves (2) of the plurality of layers are opened sequentially from a low layer to a high layer.

12. The method for using the oil well pipe string structure according to claim 8, characterized in that: If you need to control the switch sleeve (2) of some layers to close: Selecting closing short sections (4) matched with the switch sleeves (2) of the corresponding layers respectively, and connecting the adjacent closing short sections (4) in series through the matching length pipes (300) to form a closing tool (200), connecting the closing tool (200) with the service pipe string (400), and carrying the closing tool (200) through the service pipe string (400) and lowering it into the central pipe (1); The length of the distribution pipe (300) is set such that there is a distance difference between two adjacent closing short sections (4), and the plurality of closing short sections (4) can be aligned with the switch sliding sleeves (2) at corresponding layers in sequence from a high layer to a low layer, or the plurality of closing short sections (4) can be aligned with the switch sliding sleeves (2) at corresponding layers in sequence from a low layer to a high layer; When controlling a plurality of switch sleeves (2) to be closed sequentially from a high level to a low level, firstly control the closing nipple (4) at the high level to cooperate with the switch sleeve (2) at the corresponding level, lift the service pipe column (400) to close the switch sleeve (2) at the high level, then lift the pipe column to move the switch sleeve (2) at the high level upward and close it, continue to lift the pipe column to make the closing nipple (4) at the next high level cooperate with the switch sleeve (2) at the corresponding level, then lift the service pipe column (400) to move the switch sleeve (2) at the next high level upward and close it, repeat this process, so that the switch sleeves (2) at the multiple levels are closed sequentially from a high level to a low level; When controlling a plurality of switch sleeves (2) to be closed in sequence from a low layer to a high layer, firstly control the closing short joint (4) at the low layer to cooperate with the switch sleeve (2) at the corresponding layer, lift the pipe column to make the switch sleeve (2) at the low layer move upward and close, continue to lift the service pipe column (400), and make the switch sleeve (2) at the second lowest layer cooperate, then lift the service pipe column (400) again to make the switch sleeve (2) at the second lowest layer move upward and close, and repeat this process, so that the switch sleeves (2) at the plurality of layers are closed in sequence from a low layer to a high layer.

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