A back-connection plug and completion string for facilitating lateral drilling

Abstract

The utility model belongs to the drilling lining integrated well completion technical field, specifically, relate to a kind of back connection plug and well completion pipe column convenient for side tracking.The back connection plug convenient for side tracking includes: main body, the main body includes from top to bottom coaxial setting back connection cylinder release short piece and back connection bushing, and the lower end of first oil pipe is arranged in the release short piece by shear pin, and coaxial fixed setting easy drilling pipe is arranged on the upper side of back connection cylinder, and the easy drilling pipe is located the outside of first oil pipe, and the connector for being connected with the lower tool in hole is coaxially arranged in the lower end of back connection bushing.

Description

Technical Field

[0001] This utility model belongs to the field of drilling-lining integrated well completion technology, specifically, it relates to a reconnection plug that facilitates side-drilling and a well completion string that facilitates side-drilling. Background Technology

[0002] In the drill-liner integrated drilling and completion process, to meet the requirements of later open-hole sidetracking, a liner is usually first run to support the open-hole section. There is an axial gap between the upper end of the liner and the upper end of the open-hole section. Then, the lower end of the upper tubing string (small-diameter tubing) is inserted back into the liner to form a continuous tubing working channel. When sidetracking is required in the open-hole section, the upper tubing string is separated from the liner, pulled out of the well, and the open-hole section is exposed. Then, sidetracking tools are run to perform sidetracking in the open-hole section.

[0003] In actual operation, the above process has many technical problems: the use of small-sized tubing for reinsertion makes it impossible to determine whether the reinsertion is in place and the circulation channel is not sealed, which affects the normal construction of coiled tubing; if the well wall of the open hole section becomes unstable and collapses, it may even bury the connection between the upper tubing string and the liner, making it impossible to pull the upper tubing string out of the well, which increases the difficulty of handling.

[0004] The aforementioned technical problems urgently need to be solved. Utility Model Content

[0005] In view of the technical problems mentioned above, the present invention aims to provide a reconnection plug that facilitates side-drilling and a completion string that facilitates side-drilling.

[0006] According to this utility model, a reconnection plug for easy side drilling is provided, comprising: The main body includes a reconnection sleeve release section and a reconnection insertion pipe arranged coaxially from top to bottom, and the lower end of the first oil pipe is set in the release section by a shear pin; An easy-drilling pipe is coaxially fixed above the return cylinder, and the easy-drilling pipe is located outside the first oil pipe; A connector coaxially disposed at the lower end of the reconnection tube for connection with the downhole tool below.

[0007] In one specific embodiment, the connector includes a connecting cylinder coaxially fixed to the outside of the reconnection tube and a pawl coaxially disposed below the connecting cylinder. There is a gap between the inner wall of the pawl and the outer wall of the connecting cylinder, and a groove for connecting with the pawl is provided on the inner wall of the downhole tool.

[0008] In one specific embodiment, a protrusion is provided at the lower end of the reconnection tube, the protrusion being located below the pawl, and an abutment portion is provided on the inner wall of the downhole tool for axially abutting the protrusion, the abutment portion being located below the slot.

[0009] In one specific embodiment, a groove is provided on the outer wall of the reconnection tube, and the pawl is axially movable between the connecting cylinder and the protrusion. When the upper end of the pawl abuts against the connecting cylinder, the lower end of the pawl is located within the groove, thereby allowing the pawl to retract radially. When the lower end of the pawl abuts against the protrusion, the lower end of the pawl is outside the range of the groove, thus preventing the pawl from retracting radially.

[0010] In one specific embodiment, a limiting step for axially abutting the first oil pipe is provided on the inner wall of the release section.

[0011] In one specific embodiment, when the first oil pipe is fixedly connected to the release section by a shear pin, there is an axial gap between the lower end of the first oil pipe and the limiting step.

[0012] In one specific embodiment, the reconnecting cylinder is constructed with an inner diameter that gradually increases from bottom to top, and the easy-drilling tube is coaxially disposed above the reconnecting cylinder.

[0013] In one specific embodiment, the reconnecting sleeve and the release section are coaxially fixedly connected via the housing.

[0014] According to this utility model, a completion string that facilitates sidetracking is also provided, comprising: Liner; The aforementioned reconnection plug is coaxially disposed above the liner; A second oil pipe coaxially connected to the upper end of the first oil pipe inside the reconnection plug.

[0015] In one specific embodiment, the lower end of the easy-drill tube of the reconnector is located in the bare-eye section, and the upper end of the easy-drill tube is not lower than the upper end of the bare-eye section.

[0016] Compared with the prior art, the advantages of this application are as follows.

[0017] The reconnector of this utility model includes a main body and an easy-drilling pipe coaxially fixed to the upper end of the main body. During well completion, after the reconnector is inserted into the well, it connects with the liner inside the well to form a circulation channel for oil and gas extraction. When sidetracking is required, because the easy-drilling pipe is installed outside the first tubing, even if the wellbore wall becomes unstable and collapses in the open hole section, only the easy-drilling pipe will be buried, without affecting the first tubing. Therefore, the first tubing can be smoothly pulled out from the main body of the reconnector, and then the easy-drilling pipe can be drilled out before sidetracking.

[0018] The easy-drill pipe has poor corrosion resistance. In this invention, the first oil pipe is connected to the liner to form a circulation channel, so that the produced fluid will not or only comes into contact with the easy-drill pipe, thereby improving the service life of the easy-drill pipe and increasing the success rate of subsequently pulling the first oil pipe out of the reconnection plug body.

[0019] The lower end of the reconnection tube of this utility model is provided with a protrusion, and the inner wall of the connector above the liner is provided with an abutment part, so that the pressure of the lowered tube column can be used to determine whether the tube column has been reconnected in place. Attached Figure Description

[0020] The present invention will now be described with reference to the accompanying drawings.

[0021] Figure 1 This is a schematic diagram of one embodiment of the reconnection plug according to the present invention; Figure 1a and Figure 1b This is a schematic diagram of an embodiment of the connection between the reconnector and the connector according to the present invention; Figure 2 This is a schematic diagram of one embodiment of the well completion string according to the present invention; Figures 3 to 7 This is a schematic diagram illustrating the workflow of running the completion string and side-drilling the completion string according to the present invention. Figures 8 to 11 This is a schematic diagram illustrating the working process of the reconnection plug (drillable tube not shown) according to this utility model.

[0022] Figure label: 1. Liner; 2. Connector; 3. Reconnector plug; 4. First oil pipe; 6. Packer; 7. Second oil pipe; 21. Card slot; 22. Abutment part; 31. Main body; 310. Shell; 311. Reconnecting tube; 312. Release section; 313. Reconnecting sleeve; 314. Protrusion; 315. Groove; 316. Limiting step; 32. Connecting part; 321. Connecting sleeve; 322. Pawl; 33. Shear pin; 34. Easy-drill tube; 100. Completion string; 101. Open hole section; 102. Casing section.

[0023] In this application, all the accompanying drawings are schematic drawings, used only to illustrate the principle of the present invention, and are not drawn to scale. Detailed Implementation

[0024] The present invention will now be described with reference to the accompanying drawings.

[0025] It should be noted that in this application, the direction of the well completion string near the wellhead after it is inserted into the well is described as "up", "forward" or similar terms, while the direction of the well string away from the wellhead after it is inserted into the well is described as "down", "back" or similar terms.

[0026] Figure 1 The structure of the reconnector 3 according to this utility model is shown. For example... Figure 1 As shown, the reconnector 3 includes a body 31, an easy-drill tube 34, and a connector 32.

[0027] Both the main body 31 and the easy-drill tube 34 are constructed as cylindrical structures. The easy-drill tube 34 is coaxially fixed to the upper end of the main body 31 by means of a threaded connection. The lower end of the first oil pipe 4 can pass through the interior of the easy-drill tube 34 from top to bottom and reach the main body 31. The first oil pipe 4 and the main body 31 are coaxially fixedly connected by a shear pin 33.

[0028] The connector 32 is coaxially disposed at the lower end of the main body 31 for connection with the downhole tool below. In this embodiment, the downhole tool connected to the connector 32 is specifically the connector head 2, such as... Figure 2 As shown.

[0029] In this embodiment, the wellbore includes an open hole section 101 and a casing section 102 coaxially disposed above the open hole section 101. The well completion procedure using the reconnection plug 3 is as follows.

[0030] like Figure 3 As shown, the liner 1 is first lowered into the well, with its upper end face positioned below the upper end face of the open hole section 101, leaving space for subsequent sidetracking. It should be noted that in this embodiment, a connector 2 is provided at the upper end of the liner 1. The connector 2 is a part of the release assembly left after the drilling string above the liner 1 is released following the completion of drilling in the drill-liner integrated drilling process. The drill-liner integrated drilling process is well known to those skilled in the art and will not be described in detail here. Figure 4 As shown, the reconnector 3 is then assembled at the wellhead to the lower end of the first tubing 4, that is, the lower end of the first tubing 4 is inserted into the main body 31 through the easy-drill pipe 34 and fixedly connected to the main body 31 by the shear pin 33. Figure 5 As shown, the upper end of the first oil pipe 4 is then connected to the second oil pipe 7, and a packer 6 is installed on the outer wall of the second oil pipe 7. Figure 6As shown, the well completion is finally achieved by lowering the second tubing 7 to reconnect the reconnector 3 to the connector 2 at the upper end of the liner 1.

[0031] When side-drilling is required, such as Figure 7 As shown, by releasing the first tubing 4 and the return connector 3, the first tubing 4 and the second tubing 7 are pulled out of the well. Then, the easy-drill pipe 34 is drilled out, exposing the open hole section 101, which facilitates the subsequent running of side-drilling tools from the wellhead into the well for side-drilling of the open hole section 101. The method of drilling out the easy-drill pipe 34 is well known to those skilled in the art and will not be described in detail here.

[0032] When the first tubing 4 and the reconnector 3 are released, because the first tubing 4 is equipped with an easy-drill pipe 34, even if the wellbore wall of the open hole section 101 becomes unstable and collapses, only the outer wall of the easy-drill pipe 34 will be buried, without affecting the first tubing 4. Therefore, the first tubing 4 can be smoothly pulled out from the main body 31 of the reconnector 3. After the easy-drill pipe 34 is drilled out, sidetracking can be performed. The easy-drill pipe 34 has poor corrosion resistance. It forms a circulation channel through the connection between the first tubing 4 and the liner 1. The produced fluid will not or only minimally contact the easy-drill pipe 34, thereby improving the service life of the easy-drill pipe 34 and increasing the success rate of pulling the first tubing 4 out of the main body 31.

[0033] In this embodiment, the main body 31 includes a reconnection tube 313, a release section 312, and a reconnection insertion tube 311, which are coaxially and fixedly connected from top to bottom.

[0034] The connector 32 is coaxially fixed on the outside of the reconnection tube 311. Specifically, the connector 32 includes a connecting cylinder 321 and a pawl 322. The connecting cylinder 321 is coaxially fixed on the outside of the reconnection tube 311, and the pawl 322 is coaxially located at the lower end of the connecting cylinder 321. There is a gap between the inner wall of the pawl 322 and the outer wall of the connecting cylinder 321, allowing the pawl 322 to retract radially inward under external force. The diameter of the inner wall of the connector 2 is smaller than the outer diameter of the pawl 322 when no external force is applied. A groove 21 for fitting and connecting with the pawl 322 is provided on the inner wall of the connector 2. During the process of inserting the reconnection plug 3 into the connector 2 from top to bottom, the pawl 322 retracts radially under the squeezing action of the inner wall of the connector 2. When the pawl 322 reaches the position of the groove 21, the pawl 322 expands radially under its own elastic force and thus engages with the groove 21. At this time, the reconnection plug 3 and the connector 2 are reconnected.

[0035] In one specific embodiment, a protrusion 314 is provided at the lower end of the reconnection cannula 311. The protrusion 314 is located below the pawl 322, and there is an axial gap between the protrusion 314 and the pawl 322. An abutment portion 22 for fitting the protrusion 314 is provided on the inner wall of the connector 2. The abutment portion 22 is located below the slot 21, and its inner diameter is smaller than that of the protrusion 314. During the process of inserting the reconnection plug 3 into the connector 2 from top to bottom, the pawl 322 contracts radially under the squeezing action of the inner wall of the connector 2, thus entering the interior of the connector 2. When the pawl 322 reaches the position of the slot 21, it expands radially under its own elastic force, thus locking into the slot 21. At this time, the reconnection plug 3 and the connector 2 are reconnected. Simultaneously, as... Figure 8 As shown, the protrusion 314 at the lower end of the reconnection tube 311 axially abuts against the abutment portion 22 on the inner wall of the connector 2. By providing the protrusion 314 and the abutment portion 22, the insertion of the reconnection plug 3 into the connector 2 can be detected by applying pressure from the wellhead to the completion string 100. In this embodiment, a pressure of two tons is applied from the wellhead to the completion string 100. If the completion string 100 no longer moves downward, it indicates that the reconnection plug 3 has been inserted into the connector 2. Then, by lifting the completion string 100 from the wellhead, it is detected whether the pawl 322 of the reconnection plug 3 has connected with the slot 21 of the connector 2. It should be noted that when detecting the connection between the reconnection plug 3 and the connector 2 by applying pressure from the wellhead to the completion string 100 or by lifting it, the applied tonnage should be controlled within the strength range of the shear pin 33 to avoid shearing the shear pin 33.

[0036] In this embodiment, as Figure 1a and Figure 1b As shown, the pawl 322 is axially movable on the outside of the reconnection tube 311. The upper and lower ends of the pawl 322 are respectively limited by the connecting cylinder 321 and the protrusion 314. That is, the axial distance between the connecting cylinder 321 and the protrusion 314 is greater than the axial length of the pawl 322, and the pawl 322 can move within the axial range between the connecting cylinder 321 and the protrusion 314.

[0037] A groove 315 is provided on the outer wall of the reconnection cannula 311. There is an axial gap between the lower end of the groove 315 and the upper end of the protrusion 314.

[0038] During the insertion of the reconnector 3 into the connector 2, the outer diameter of the pawl 322 is larger than the inner diameter of the upper part of the connector 2. Therefore, the connector 2 applies an upward thrust to the pawl 322, causing the upper end of the pawl 322 to axially abut against the connector tube 321. At this time, the lower end of the pawl 322 is located in the groove 315. Under the pressure of the inner wall of the connector 2, the pawl 322 can radially retract into the groove 315, thereby allowing the entire reconnector 3 to be inserted into the connector 2. When the protrusion 314 of the reconnection tube 311 axially abuts against the abutment portion 22 of the inner wall of the connector 2, the pawl 322 engages with the slot 21 of the connector 2. When the reconnector 3 is lifted, the pawl 322 remains stationary under the engagement of the slot 21. The reconnector tube 311 moves upward relative to the pawl 322, causing the lower end of the pawl 322 to axially abut against the protrusion 314 at the lower end of the reconnector tube 311. Furthermore, the groove 315 on the outer wall of the reconnector tube 311 moves upward relative to the pawl 322. At this point, the lower end of the pawl 322 is no longer within the groove 315. The inner and outer sides of the pawl 322 abut against the outer wall of the reconnector tube 311 and the inner wall of the connector 2, respectively. This prevents the pawl 322 from retracting radially and from disengaging from the slot 21, thus preventing the reconnector 3 from separating from the connector 2. Figure 1b As shown.

[0039] In this embodiment, an internal thread is provided on the inner wall of the lower end of the release section 312, and an external thread is provided on the outer wall of the upper end of the reconnection tube 311. The release section 312 is coaxially fixedly connected to the upper part of the reconnection tube 311 by means of threaded connection. The first oil pipe 4 is coaxially disposed inside the release section 312, and the first oil pipe 4 and the release section 312 are fixedly connected by a shear pin 33.

[0040] After the pawl 322 of the reconnector 3 is connected to the slot 21 of the connector 2, the shear pin 33 is cut off by applying pressure from the wellhead to the completion string 100. Figure 9 As shown, this separates the first oil pipe 4 from the release section 312 of the reconnection plug 3. Figure 10 As shown, at this time, the first tubing 4 and the tubing string above it can be moved up or down to adjust the position of the wellhead tubing string, which facilitates the installation of the wellhead equipment.

[0041] In this embodiment, a limiting step 316 is provided on the inner wall of the release section 312. The inner diameter of the limiting step 316 is smaller than the outer diameter of the first oil pipe 4, and it is used to axially abut against the first oil pipe 4. The limiting step 316 is located below the first oil pipe 4. When the first oil pipe 4 is fixedly connected to the release section 312 by the shear pin 33, there is an axial gap between the lower end face of the first oil pipe 4 and the limiting step 316, thereby providing space for the subsequent vertical movement of the first oil pipe 4 to adjust the tubing.

[0042] In this embodiment, the reconnecting sleeve 313 is coaxially fixed above the release section 312, and the easy-drill tube 34 is coaxially fixed above the reconnecting sleeve 313 via a threaded connection. The reconnecting sleeve 313 is constructed with an inner diameter that gradually increases from bottom to top, serving as a guide for the insertion of the first oil pipe 4, allowing the first oil pipe 4 to be repeatedly inserted into the reconnecting sleeve 313. Figure 11 As shown, after adjusting the position of the wellhead tubing string, the first tubing 4 can be re-inserted into the release sub 312 under the guidance of the reconnection sleeve 313.

[0043] In a specific embodiment, such as Figure 1 As shown, the reconnecting sleeve 313 and the release section 312 are coaxially fixedly connected via the housing 310. An external thread is provided at the upper end of the housing 310 for coaxial fixed connection with the reconnecting sleeve 313, and an external thread is provided at the lower end of the housing 310 for coaxial fixed connection with the release section 312. The upper and lower ends of the housing 310 are coaxially fixedly connected to the reconnecting sleeve 313 and the release section 312 respectively via external threads.

[0044] Figure 2 The structure of the well completion string 100 according to this utility model is shown. For example... Figure 2 As shown, the completion string 100 includes a liner 1, a reconnection plug 3, a first tubing 4, and a second tubing 7.

[0045] The liner 1 is installed inside the open hole section 101, and there is an axial gap between the upper end face of the liner 1 and the upper end face of the open hole section 101 to allow space for subsequent side-drilling. The reconnector 3 is coaxially connected to the upper end of the liner 1 via the connector 2. The first tubing 4 is coaxially connected to the body 31 of the reconnector 3 via the shear pin 33. The second tubing 7 is coaxially connected to the upper end of the first tubing 4. The easy-drill pipe 34 of the reconnector 3 is not connected to the second tubing 7. The lower end of the easy-drill pipe 34 is located inside the open hole section 101 to facilitate subsequent side-drilling. The upper end face of the easy-drill pipe 34 is not lower than the upper end face of the open hole section 101, thereby preventing cuttings generated after the wellbore of the open hole section 101 collapses from falling into the easy-drill pipe 34.

[0046] like Figures 3 to 7 The completion process of the completion string 100 is shown, as well as the workflow for sidetracking the completion string 100.

[0047] The completion process for a 100mm completion string is as follows. For example... Figure 3As shown, the liner 1 is first lowered into the well, with its upper end face positioned below the upper end face of the open hole section 101, leaving space for subsequent sidetracking. It should be noted that in this embodiment, a connector 2 is provided at the upper end of the liner 1. The connector 2 is a part of the release assembly left after the drilling string above the liner 1 is released following the completion of drilling in the drill-liner integrated drilling process. The drill-liner integrated drilling process is well known to those skilled in the art and will not be described in detail here. Figure 4 As shown, the reconnector 3 is then assembled to the lower end of the first tubing 4 at the wellhead. Figure 5 As shown, the upper end of the first oil pipe 4 is then connected to the second oil pipe 7, and a packer 6 is installed on the outer wall of the second oil pipe 7. Figure 6 As shown, the reconnector 3 is finally reconnected to the connector 2 at the upper end of the liner 1 via the second tubing 7 below. Then, the wellhead string position is adjusted to set the packer 6.

[0048] When side-drilling is required, such as Figure 7 As shown, by releasing the first tubing 4 and the return connector 3, the first tubing 4 and the second tubing 7 are pulled out of the well. Then, the easy-drill pipe 34 is drilled out, exposing the open hole section 101, which facilitates the subsequent running of side-drilling tools from the wellhead into the well for side-drilling of the open hole section 101. The method of drilling out the easy-drill pipe 34 is well known to those skilled in the art and will not be described in detail here.

[0049] The structure of packer 6 is well known to those skilled in the art and will not be described in detail here.

[0050] According to this utility model, a method for constructing a well completion string is also provided, including the following steps.

[0051] First, the liner 1 is lowered into the well, with its upper end face positioned below the upper end face of the open hole section 101, leaving space for subsequent side-drilling. Figure 3 As shown. It should be noted that in this embodiment, a connector 2 is provided at the upper end of the liner 1. The connector 2 is a part of the release component left after the drilling string above the liner 1 is released after drilling is completed in the drill-liner integrated drilling process. The drill-liner integrated drilling process is well known to those skilled in the art and will not be described in detail here.

[0052] like Figure 4 As shown, the reconnector 3 is then assembled at the wellhead to the lower end of the first tubing 4.

[0053] like Figure 5 As shown, the upper end of the first oil pipe 4 is then connected to the second oil pipe 7, and a packer 6 is provided on the outer wall of the second oil pipe 7.

[0054] like Figure 6As shown, the reconnection plug 3 is reconnected to the connector 2 at the upper end of the liner 1 via the second oil pipe 7 below. Figure 8 As shown, at this time, the pawl 322 of the reconnector plug 3 is connected to the slot 21 of the connector 2.

[0055] Then, apply a two-ton downforce to the completion string 100. If the completion string 100 no longer moves down, it indicates that the protrusion 314 of the reconnector 3 has abutted against the contact portion 22 of the connector 2, and the reconnector 3 has been inserted into the connector 2. Next, by lifting the completion string 100 from the wellhead, check whether the pawl 322 of the reconnector 3 has connected with the slot 21 of the connector 2. If the first tubing 4 and the tubing above it do not move upward or move upward a very small distance (the distance from when the pawl 322 abuts against the upper connector 321 to when it abuts against the lower protrusion 314) and then stop, it indicates that the pawl 322 of the reconnector 3 has connected with the slot 21 of the connector 2. It should be noted that when checking the connection between the reconnector 3 and the connector 2 by applying pressure to or lifting the completion string 100 from the wellhead, the applied tonnage should be controlled within the strength range of the shear pin 33 to avoid shearing the shear pin 33.

[0056] like Figure 9 As shown, by applying pressure from the wellhead to the completion string 100, the first tubing 4 moves downward relative to the release section 312, shearing the shear pin 33 and separating the first tubing 4 from the release section 312 of the reconnection plug 3. Figure 10 As shown, the first tubing 4 and the second tubing 7 can be moved up or down at this time to adjust the position of the wellhead tubing string, facilitating the installation of the wellhead equipment. The process of adjusting the position of the wellhead tubing string is as follows: The second tubing 7 is composed of multiple short tubings connected in series. When the reconnector 3 has been inserted into the connector 2 and connected to each other, if the upper end of the second tubing 7 exceeds the specified height of the wellhead, the second tubing 7 is pulled up, and the uppermost short tubing of the second tubing 7 is replaced with a shorter tubing, so that after the first tubing 4 is reconnected to the reconnector 313 and the release section 312, the uppermost end of the second tubing 7 can be located at the specified height of the wellhead. The process of replacing the uppermost short tubing of the second tubing 7 when adjusting the position of the wellhead tubing string is well known to those skilled in the art and will not be described in detail here.

[0057] like Figure 11 As shown, the first tubing 4 and the second tubing 7 are lowered, so that the first tubing 4 is reconnected to the reconnection plug 3 through the reconnection sleeve 313, and the packer 6 is set, thus completing the well completion work.

[0058] When sidetracking is required or well workover is needed in the upper section, such as Figure 7As shown, the packer 6 is unsealed, and then the second tubing 7 and the first tubing 4 are pulled up directly from the wellhead position to separate the body 31 of the reconnector plug 3 from the first tubing 4. The first tubing 4 and the second tubing 7 are pulled out of the well, and then the easy-drill pipe 34 is drilled out to expose the open hole section 101. The side-drilling tool is then lowered to perform side-drilling on the open hole section 101.

[0059] In the description of this utility model, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified.

[0060] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0061] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0062] Finally, it should be noted that the above description is merely a preferred embodiment of this utility model and does not constitute any limitation on this utility model. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A reconnection plug for easy side drilling, characterized in that, include: The main body (31) includes a reconnection tube (313), a release section (312) and a reconnection insertion tube (311) arranged coaxially from top to bottom. The lower end of the first oil pipe (4) is set in the release section (312) by a shear pin (33). An easy-drilling pipe (34) is coaxially fixed above the return sleeve (313), and the easy-drilling pipe (34) is located outside the first oil pipe (4); A connector (32) is coaxially disposed at the lower end of the reconnection tube (311) for connection with the downhole tool below.

2. The reconnection plug according to claim 1, characterized in that, The connector (32) includes a connecting cylinder (321) coaxially fixed on the outside of the reconnection tube (311) and a pawl (322) coaxially disposed below the connecting cylinder (321). There is a gap between the inner wall of the pawl (322) and the outer wall of the connecting cylinder (321). A slot (21) for connecting with the pawl (322) is provided on the inner wall of the downhole tool.

3. The reconnector according to claim 2, characterized in that, A protrusion (314) is provided at the lower end of the reconnection tube (311), the protrusion (314) being located below the pawl (322), and an abutment (22) is provided on the inner wall of the downhole tool for axially abutting the protrusion (314), the abutment (22) being located below the slot (21).

4. The reconnector according to claim 3, characterized in that, A groove (315) is provided on the outer wall of the reconnection tube (311), and the pawl (322) is axially movable between the connecting cylinder (321) and the protrusion (314). When the upper end of the pawl (322) abuts against the connecting cylinder (321), the lower end of the pawl (322) is located within the range of the groove (315), thereby allowing the pawl (322) to retract radially. When the lower end of the pawl (322) abuts against the protrusion (314), the lower end of the pawl (322) is outside the range of the groove (315), thereby preventing the pawl (322) from retracting radially.

5. The reconnector according to claim 1, characterized in that, The inner wall of the release section (312) is provided with a limiting step (316) for axially abutting the first oil pipe (4).

6. The reconnector according to claim 5, characterized in that, When the first oil pipe (4) is fixedly connected to the release section (312) by the shear pin (33), there is an axial gap between the lower end of the first oil pipe (4) and the limiting step (316).

7. The reconnector according to claim 6, characterized in that, The return tube (313) is constructed with an inner diameter that gradually increases from bottom to top, and the easy-drill tube (34) is coaxially arranged above the return tube (313).

8. The reconnection plug according to claim 1, characterized in that, The return tube (313) and the drop-out section (312) are coaxially fixedly connected by the housing (310).

9. A well completion string, characterized in that, include: Liner (1); A reconnection plug (3) according to any one of claims 1 to 8 is coaxially disposed above the liner (1); A second oil pipe (7) is coaxially connected to the upper end of the first oil pipe (4) inside the reconnection plug (3).

10. The completion string according to claim 9, characterized in that, The lower end of the easy-drill tube (34) of the reconnection plug (3) is located in the bare eye section (101), and the upper end of the easy-drill tube (34) is not lower than the upper end of the bare eye section (101).

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