Petroleum tubing special thread with sealing surface at end part

Abstract

A petroleum oil pipe special thread with a sealing surface at the end relates to the technical field of petroleum exploitation pipe fittings, and comprises an oil pipe and a coupling, special threads are respectively processed on the outer side of the oil pipe and the inner side of the coupling, and the oil pipe is connected with the coupling through the special threads; an elastic sealing assembly is arranged at the end of the oil pipe and comprises an elastic metal ring with a U-shaped section, a U-shaped opening of the elastic metal ring faces the oil pipe, one straight edge of the elastic metal ring is fixedly connected with the oil pipe in a sealed mode, and the other straight edge of the elastic metal ring is in a free state. A disc spring is arranged on the inner side of the elastic metal ring and abuts against the position between the two straight edges of the elastic metal ring. The oil pipe coupling solves the problem that the sealing performance of the oil pipe and the coupling end face is reduced, it is guaranteed that the same sealing effect can be achieved on the sealing face when the coupling is connected with the oil pipe every time, and the sealing strength is good.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the technical field of petroleum exploitation pipe fitting, especially relates to a special thread of petroleum oil pipe with sealing surface at the end. BACKGROUND

[0002] In order to meet the high performance requirement of oil pipe and casing sealing connection in deep well, super deep well, high pressure well, thermal recovery well and the like, the prior art generally adopts the oil pipe with special thread, because the sealing property of special thread connection is much higher than that of ordinary thread.

[0003] The connection of the existing oil pipe with special thread and the coupling with special thread relies on the sealing of special thread in addition to the connection, and the outer sealing surface of the pipe body is processed at the end of the oil pipe, and the inner sealing surface of the coupling is processed at the inner side of the coupling, so that the secondary sealing effect is formed by the interference fit of the outer sealing surface of the pipe body and the inner sealing surface of the coupling. The defect of the prior art is that the sealing property of the interference fit of the outer sealing surface of the pipe body and the inner sealing surface of the coupling is good when sealed for the first time, however, after the oil pipe and the coupling are disassembled once, the sealing effect of the interference fit of the sealing surface is reduced from the second time, because the interference fit has deformed the sealing surface, so that the interference fit effect of the sealing surface is greatly reduced from the second time. In order to ensure that the sealing surface can produce the same sealing effect every time the coupling and the oil pipe are connected, the utility model is improved. UTILITY MODEL CONTENT

[0004] In order to solve the problem that the end surface sealing surface of the oil pipe and the coupling can produce the same sealing effect every time, the utility model provides a special thread of petroleum oil pipe with sealing surface at the end, the utility model not only can produce the same sealing effect every time, but also the sealing effect has very high sealing property.

[0005] The utility model provides a technical scheme: a special thread of petroleum oil pipe with sealing surface at the end, including oil pipe and coupling, the outside of oil pipe and the inside of coupling are processed with special thread respectively, and the oil pipe and the coupling are connected through the special thread, the end of oil pipe is provided with elastic sealing assembly, the elastic sealing assembly includes the elastic metal ring of section U, the U type opening of elastic metal ring faces oil pipe, one straight edge of elastic metal ring is fixedly connected with oil pipe, the other straight edge of elastic metal ring is in free state, the inside of elastic metal ring is provided with disc spring, and the disc spring is resisted between the two straight edges of elastic metal ring.

[0006] Further technical scheme is: the end of the straight edge of the elastic metal ring in the free state is provided with the straight angle shaped flange, and the flange is located on the outer wall of the oil pipe.

[0007] Further technical scheme is: the outside of the elastic metal ring is provided with the elastic sealing layer, and the material of the elastic sealing layer is rubber

[0008] Further technical solutions are: the elastic metal ring material is spring steel.

[0009] Compared with the prior art, the present application has the following advantages:

[0010] 1. The utility model discloses a set up elastic sealing assembly, ensure that every time the coupling is connected with the oil pipe, and the sealing surface can produce the same sealing effect, and the sealing strength is good.

[0011] 2. The disc spring in the utility model plays the role of increasing the sealing strength, and ensures that the sealing of the end surface can withstand higher pressure. Meanwhile, the disc spring can play the role of avoiding the non-rebound of the U-shaped elastic metal ring. DETAILED DESCRIPTION

[0012] Figure 1 is the cross section schematic view of the utility model.

[0013] Figure 2 is Figure 1 the local enlarged view of A in

[0014] In the drawing: 1, coupling; 2, oil pipe; 3, elastic sealing layer; 4, elastic metal ring; 5, disc spring. DETAILED DESCRIPTION

[0015] In order to make the technical problems, technical schemes and beneficial effects of the utility model to be solved more clearly, the utility model is further described in detail below by combining with the drawings and examples. It should be understood that the specific examples described here are only used to explain the utility model, and are not used to limit the utility model.

[0016] The embodiment discloses a special thread of petroleum oil pipe with sealing surface at the end, and the structure comprises an oil pipe and a coupling, the outer side of the oil pipe and the inner side of the coupling are respectively provided with special threads, and the oil pipe and the coupling are connected through the special threads. The above is a technical scheme that already exists in the prior art, and will not be repeated here.

[0017] The innovation of the embodiment is that the end of the oil pipe 2 is provided with an elastic sealing assembly, the elastic sealing assembly comprises an elastic metal ring 4 with a U-shaped cross section, the U-shaped opening of the elastic metal ring 4 faces the oil pipe 2, one straight edge of the elastic metal ring 4 is fixedly and sealingly connected with the oil pipe 2, the other straight edge of the elastic metal ring 4 is in a free state, a disc spring 5 is arranged on the inner side of the elastic metal ring 4, and the disc spring 5 abuts between the two straight edges of the elastic metal ring 4. After the oil pipe 2 is screwed with the coupling 1, one side of the elastic metal ring 4 is fixedly and sealingly connected with the oil pipe 2, the other side of the elastic metal ring 4 is extruded and tightly abuts against the inner sealing surface of the coupling 1, at this time, the disc spring 5 is extruded and deformed, and since the elastic force of the disc spring 5 after compression and deformation is large, the sealing effect of the other side of the elastic metal ring 4 and the coupling 1 is excellent under the action of the disc spring 5. The excellent sealing effect does not change with the change of the number of times of disassembly and connection of the oil pipe 2 and the coupling 1. Since the sealing effect of the disc spring 5 is excellent, the sealing at the end surface can withstand higher pressure, and the use requirement of a high-pressure well is met.

[0018] In the application, when the U-shaped elastic metal ring 4 is extruded, the bent edge can sealingly abut against the coupling 1, and a sealing is formed again, so that the sealing effect is better.

[0019] In the application, the material of the elastic metal ring 4 is spring steel, although the elastic metal ring 4 has good resilience, but the annular well bottom is harsh, and the situation that the elastic metal ring 4 cannot rebound cannot be excluded, the disc spring 5 in the application plays a role in forcing the elastic metal ring 4 to rebound, and reduces the failure rate of the whole sealing assembly.

Claims

1. A special thread of an oil pipe (2) with a sealing surface at the end, comprising an oil pipe (2) and a coupling (1), the outer side of the oil pipe (2) and the inner side of the coupling (1) are respectively processed with a special thread, the oil pipe (2) and the coupling (1) are connected through the special thread, characterized in that: The end of the oil pipe (2) is provided with an elastic sealing assembly, which comprises an elastic metal ring (4) with a U-shaped cross section, the U-shaped opening of the elastic metal ring (4) faces the oil pipe (2), one straight edge of the elastic metal ring (4) is fixedly and sealingly connected with the oil pipe (2), the other straight edge of the elastic metal ring (4) is in a free state, the inner side of the elastic metal ring (4) is provided with a disc spring (5), and the disc spring (5) abuts between the two straight edges of the elastic metal ring (4).

2. A premium thread for an oil country tubular good (2) with a sealing shoulder at the end, according to claim 1, characterized in that: The end of the straight edge of the elastic metal ring (4) in the free state is provided with a right-angle-shaped folded edge, and the folded edge is located on the outer wall of the oil pipe (2).

3. A premium thread for an oil country tubular good (2) with a sealing shoulder at the end, according to claim 1, characterized in that: The outer side of the elastic metal ring (4) is provided with an elastic sealing layer (3).

4. A premium thread for an oil country tubular good (2) with a sealing shoulder according to claim 1, characterized in that: The material of the elastic metal ring (4) is spring steel.

5. A premium thread for an oil country tubular good (2) with a sealing shoulder according to claim 3, characterized in that: The material of the elastic sealing layer (3) is rubber.

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