Direct connection type special thread oil casing

Abstract

The utility model discloses a direct connection type special thread oil casing which comprises one or more direct connection pipe bodies connected end to end and a multifunctional well cementation connector connected with the direct connection pipe body on the leftmost side. The left end of the direct connection pipe body is of an external thread structure, and the right end is of an internal thread structure. The multifunctional well cementation connector comprises an upper connecting structure arranged at the left end, a lower connecting structure arranged at the right end and a middle bearing ring arranged in the middle. Joint external threads are arranged on the outer circumferential surface of the upper connecting structure, and joint internal threads are arranged on the inner circumferential surface; the lower connecting structure comprises a lower connecting inner thread, an inner sealing conical surface and an inner secondary sealing shoulder, and the depth of the lower connecting structure is smaller than the length of the outer thread structure. By the adoption of the design of the multifunctional well cementation connector, the function of lifting a short section can be achieved, a cement head can be directly connected, later-period circulating well cementation is facilitated, the multifunctional well cementation connector has multiple functions, cost is saved, construction efficiency is improved, and the multifunctional well cementation connector is convenient to popularize and use in industry.

Description

Technical Field

[0001] This utility model relates to the field of oil casing structure technology, and in particular to a direct-connection special snap-fit ​​oil casing. Background Technology

[0002] Currently, the oil casing used in engineering typically includes two types: direct connection type and coupling type. Direct connection type does not require coupling and is directly connected using the pipes; coupling type requires coupling and is connected between the two pipes using coupling. Due to its structural feature of a smaller outer diameter of the joint compared to the coupling outer diameter of conventional oil casing, direct connection type oil casing is widely used in wells with small diameters, situations where running-in encounters jamming, and relatively difficult operations such as window drilling and old well repair. It is beneficial for downhole operations such as running-in and cementing.

[0003] However, current direct-connection casing lifting systems mostly use safety slips or drill pipe lifting joints, lacking dedicated lifting joints. Using safety slips is cumbersome and inefficient, and in deep wells, it can damage the casing. Drill pipe lifting joints are also bulky and inconvenient to operate. Existing standard cementing heads connect to the casing string using API standard round threads or trapezoidal threads, which cannot be directly connected to special threads. Utility Model Content

[0004] In view of the technical problems mentioned in the background art above, the purpose of this utility model is to provide a direct connection type special threaded oil sleeve.

[0005] To achieve the above objectives, the technical solution provided by this utility model is as follows:

[0006] This application provides a direct-connection special oil casing, including one or more direct-connection pipes connected end to end and a multi-functional cementing joint connected to the leftmost direct-connection pipe.

[0007] The left end of the straight-connected pipe has an external thread structure, and the right end has an internal thread structure;

[0008] The multi-functional cementing connector includes an upper connecting structure at the left end, a lower connecting structure at the right end, and a central support ring at the middle. The upper connecting structure has an external thread on its outer circumferential surface and an internal thread on its inner circumferential surface. The lower connecting structure includes a lower internal thread, an inner sealing cone surface, and an inner secondary sealing shoulder. The depth of the lower connecting structure is less than the length of the external thread structure.

[0009] The external thread structure includes, from the outside to the inside, an outer secondary sealing shoulder, an outer sealing conical surface, a first external thread, an outer cylindrical plane, and an outer main sealing shoulder.

[0010] The internal thread structure includes, from the outside to the inside, an inner main sealing shoulder, an inner cylindrical plane, a first internal thread, an inner sealing cone surface, and an inner secondary sealing shoulder;

[0011] When connected, the external thread structure of one straight-connect special oil sleeve is screwed to the internal thread structure of another straight-connect special oil sleeve.

[0012] When the external thread structure and the internal thread structure are screwed together, the first external thread of the external thread structure is screwed into the first internal thread of the internal thread structure. As it is tightened, the external sealing cone surface and the external main sealing shoulder gradually come into contact with the internal sealing cone surface and the internal main sealing shoulder, respectively, until an interference fit is formed. The external secondary sealing shoulder and the internal secondary sealing shoulder are in clearance fit, with a clearance of S=0.03~0.10mm.

[0013] The external thread of the connector on the outer circumferential surface of the upper connecting structure is an API standard round thread, and the internal thread of the connector on the inner circumferential surface is an API standard trapezoidal thread, or the external thread of the connector is an API standard trapezoidal thread and the internal thread of the connector is an API standard round thread.

[0014] The pitch of the first internal thread and the first external thread is 5.08 mm, the included angle of the bearing surface is 10°, the included angle of the guide surface is 3°, and the taper is 0.0625~0.0833 mm / mm.

[0015] The outer diameter of the direct connection pipe is 114.3~339.7mm, and the outer diameter of the pipe is equal to the outer diameter of the multi-functional cementing joint, which is less than the outer diameter of the central support ring. The inner diameter of the pipe is equal to the inner diameter of the multi-functional cementing joint.

[0016] The outer circumference of the central support ring is provided with a wrench socket, the depth of which is ≤ (outer diameter of the central support ring - outer diameter of the multi-functional cementing connector) / 2.

[0017] The multi-functional cementing joint is made of aluminum alloy.

[0018] Among them, the internal threads, internal sealing cone surface, and internal main sealing shoulder of the lower connection structure are copper plated.

[0019] Compared with the prior art, the beneficial effects of this utility model are:

[0020] 1. Compared with the direct connection type and coupling type used in traditional technologies, the outer diameter of this utility model is much smaller, consistent with the outer diameter of the casing, which greatly increases the annular clearance of the wellbore and fully meets the needs of special working conditions such as small wellbore, blockage during running-in, and difficult operation, such as window-opening side-drilling and old well repair. This utility model adopts a multi-functional cementing joint design, which can not only play the role of lifting the short section, but also directly connect the cement head for easy subsequent circulation cementing. It is multi-functional, saves costs and improves construction efficiency, and is easy to promote and use in the industry.

[0021] 2. This utility model adopts a design with the same outer diameter and the same inner diameter, and the inner and outer surfaces are flush, which reduces hydraulic pressure loss, improves construction efficiency, and facilitates subsequent well operations. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the overall structure provided for an embodiment of this application;

[0023] Figure 2 A schematic diagram of a direct-connection oil casing structure provided for an embodiment of this application;

[0024] Figure 3 A schematic diagram of the internal and external threaded assembly structure provided for embodiments of this application;

[0025] Figure 4 A schematic diagram of the thread profile is provided for the embodiments of this application;

[0026] Figure 5 A schematic cross-sectional view of the multifunctional cementing joint structure provided in the embodiments of this application;

[0027] Figure 6 An enlarged schematic diagram of the secondary shoulder assembly of the internal and external thread structure provided in the embodiments of this application;

[0028] In the diagram: 1-Multi-functional cementing connector, 2-Straight connecting pipe body, 11-Upper connecting structure, 12-Middle support ring, 13-Lower connecting structure, 21-External thread structure, 22-Internal thread structure, 111-Connector external thread, 112-Connector internal thread, 211-Outer secondary sealing shoulder, 212-Outer sealing cone surface, 213-External thread, 214-Outer cylindrical plane, 215-Outer main sealing shoulder, 221-Inner secondary sealing shoulder, 2 22-Inner sealing conical surface, 223-Internal thread, 224-Inner cylindrical plane, 225-Inner main sealing shoulder, D-Specification outer diameter, D1-Specification outer diameter of multi-functional cementing joint, D2-Outer diameter of central support ring, d-Specification inner diameter, d1-Inner diameter of multi-functional cementing joint, P-Pitch, B-Guide surface angle, A-Bearing surface angle, t-Socket depth, S-Clearance, L1-Depth of lower connection structure, L2-Length of external thread structure. Detailed Implementation

[0029] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0030] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and are not intended to indicate or imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0031] In the description of this patent, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "setting" should be interpreted broadly. For example, they can refer to a fixed connection or setting, a detachable connection or setting, or an integral connection or setting; they can refer to a direct connection or an indirect connection. Those skilled in the art can understand the specific meaning of the above terms in this patent according to the specific circumstances.

[0032] Please see Figures 1-6 The diagram shows the structure of an embodiment provided by this utility model.

[0033] This embodiment provides a direct-connection special oil casing, including one or more direct-connection pipe bodies 2 connected end to end and a multi-functional cementing connector 1 connected to the leftmost direct-connection pipe body.

[0034] The left end of the straight-connected pipe 2 has an external thread structure 21, and the right end has an internal thread structure 22;

[0035] The multi-functional cementing connector 1 includes an upper connecting structure 11 at the left end, a lower connecting structure 13 at the right end, and a central support ring 12 in the middle. The upper connecting structure 11 has an external thread 111 on its outer circumferential surface and an internal thread 112 on its inner circumferential surface. The lower connecting structure 13 includes a lower internal thread 223, an inner sealing cone surface 222, and an inner secondary sealing shoulder 221. The depth L1 of the lower connecting structure is less than the length L2 of the external thread structure.

[0036] It should be noted that, compared with the direct connection type and coupling type used in traditional technologies, the outer diameter of this utility model is much smaller, consistent with the outer diameter of the casing, which greatly increases the annular clearance of the wellbore and fully meets the needs of special working conditions such as small wellbore, blockage during downhole drilling, and difficult operation, such as window side-drilling and old well repair. This utility model adopts a multi-functional cementing joint design, which can not only play the role of lifting the short section, but also directly connect the cement head for easy subsequent circulation cementing. It is multi-functional, saves costs and improves construction efficiency, and is easy to promote and use in the industry.

[0037] In addition, the external thread structure 21 includes an outer secondary sealing shoulder 211, an outer sealing cone surface 212, a first external thread 213, an outer cylindrical plane 214, and an outer main sealing shoulder 215 arranged sequentially from the outside to the inside.

[0038] The internal thread structure 22 includes an inner main sealing shoulder 225, an inner cylindrical plane 224, a first internal thread 223, an inner sealing cone surface 222, and an inner secondary sealing shoulder 221 arranged sequentially from the outside to the inside.

[0039] When connected, the external thread structure 21 of one straight pipe body 2 is screwed to the internal thread structure 22 of another straight pipe body 2.

[0040] When the external thread structure 21 and the internal thread structure 22 are screwed together, the first external thread 213 of the external thread structure 21 is screwed into the first internal thread 223 of the internal thread structure 22. As it is tightened, the external sealing cone surface 212 and the external main sealing shoulder 215 gradually come into contact with the internal sealing cone surface 222 and the internal main sealing shoulder 225, respectively, until an interference fit is formed. The external secondary sealing shoulder 211 and the internal secondary sealing shoulder 221 are in clearance fit, and the clearance amount S = 0.03~0.10mm.

[0041] Among them, the external thread 111 of the connector on the outer circumferential surface of the upper connecting structure 11 is an API standard round thread, and the internal thread 112 of the connector on the inner circumferential surface is an API standard trapezoidal thread, or the external thread 111 of the connector is an API standard trapezoidal thread and the internal thread 112 of the connector is an API standard round thread.

[0042] Among them, the pitch P of the first internal thread 223 and the first external thread 213 is 5.08mm, the bearing surface angle A is 10°, the guide surface angle B is 3°, and the taper is 0.0625~0.0833mm / mm.

[0043] Among them, the outer diameter of the straight connecting pipe body 2 is D=114.3~339.7mm, and the outer diameter of the specification D=the outer diameter of the multi-functional cementing joint D1<the outer diameter of the middle support ring D2, and the inner diameter of the specification d=the inner diameter of the multi-functional cementing joint d1.

[0044] This utility model adopts a design with the same outer diameter and the same inner diameter, and the inner and outer surfaces are flush, which reduces hydraulic pressure loss, improves construction efficiency, and facilitates subsequent downhole operations.

[0045] Among them, the outer circumference of the central support ring 12 is provided with a wrench socket, the depth of which is t≤(outer diameter of the central support ring D2-outer diameter of the multi-functional cementing joint D1) / 2.

[0046] The multi-functional cementing connector 1 is made of aluminum alloy. It should be noted that the aluminum alloy was purchased externally and is a material known in the prior art.

[0047] Among them, the surfaces of the internal thread 223, the internal sealing cone surface 222, and the internal main sealing shoulder 225 of the lower connecting structure 13 are plated with copper.

[0048] The foregoing has shown and described the basic principles, main features, and advantages of this utility model. Those skilled in the art should understand that this utility model is not limited to the above embodiments. The embodiments and descriptions in the specification are merely preferred examples and are not intended to limit the utility model. Various changes and modifications can be made to this utility model without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed utility model. The scope of protection of this utility model is defined by the appended claims and their equivalents.

Claims

1. A direct-connection type special threaded oil sleeve, characterized in that, It includes one or more straight connecting pipes (2) connected end to end and a multi-functional cementing joint (1) connected to the leftmost straight connecting pipe. The left end of the straight connecting pipe (2) has an external thread structure (21), and the right end has an internal thread structure (22). The multi-functional cementing joint (1) includes an upper connecting structure (11) at the left end, a lower connecting structure (13) at the right end, and a central support ring (12) at the middle. The upper connecting structure (11) has an external thread (111) on its outer circumferential surface and an internal thread (112) on its inner circumferential surface. The lower connecting structure (13) includes a lower internal thread (223), an inner sealing cone (222), and an inner secondary sealing shoulder (221). The depth (L1) of the lower connecting structure is less than the length (L2) of the external thread structure.

2. The direct-connection special threaded oil sleeve according to claim 1, characterized in that, The external thread structure (21) includes an outer secondary sealing shoulder (211), an outer sealing cone surface (212), a first external thread (213), an outer cylindrical plane (214), and an outer main sealing shoulder (215) arranged sequentially from the outside to the inside. The internal thread structure (22) includes an inner main sealing shoulder (225), an inner cylindrical plane (224), a first internal thread (223), an inner sealing cone surface (222), and an inner secondary sealing shoulder (221) arranged sequentially from the outside to the inside. When connected, the external thread structure (21) of one straight connecting pipe (2) is screwed to the internal thread structure (22) of the other straight connecting pipe (2); When the external thread structure (21) and the internal thread structure (22) are screwed together, the first external thread (213) of the external thread structure (21) is screwed into the first internal thread (223) of the internal thread structure (22). As it is tightened, the external sealing cone surface (212) and the external main sealing shoulder (215) gradually come into contact with the internal sealing cone surface (222) and the internal main sealing shoulder (225) respectively, until an interference fit is produced. The external secondary sealing shoulder (211) and the internal secondary sealing shoulder (221) are in clearance fit, and the clearance amount S = 0.03~0.10mm.

3. The direct-connection special threaded oil sleeve according to claim 2, characterized in that, The external thread (111) of the connector on the outer circumferential surface of the upper connecting structure (11) is an API standard round thread, and the internal thread (112) of the connector on the inner circumferential surface is an API standard trapezoidal thread, or the external thread (111) of the connector is an API standard trapezoidal thread and the internal thread (112) of the connector is an API standard round thread.

4. The direct-connection special threaded oil sleeve according to claim 3, characterized in that, The pitch (P) of the first internal thread (223) and the first external thread (213) is 5.08 mm, the bearing surface angle (A) is 10°, the guide surface angle (B) is 3°, and the taper is 0.0625~0.0833 mm / mm.

5. The direct-connection special threaded oil sleeve according to claim 4, characterized in that, The outer diameter (D) of the direct connection pipe (2) is 114.3~339.7mm, and the outer diameter (D) is equal to the outer diameter (D1) of the multi-functional cementing joint and the outer diameter (D2) of the middle support ring. The inner diameter (d) is equal to the inner diameter (d1) of the multi-functional cementing joint.

6. The direct-connection special threaded oil sleeve according to claim 5, characterized in that, A wrench socket is provided on the outer circumference of the central support ring (12), with a socket depth of... 。 7. The direct-connection special threaded oil sleeve according to claim 1, characterized in that, The multi-functional cementing connector (1) is made of aluminum alloy.

8. The direct-connection special threaded oil sleeve according to claim 1, characterized in that, The surfaces of the internal thread (223), the internal sealing cone (222), and the internal main sealing shoulder (225) of the lower connecting structure (13) are copper plated.

Images