Variable-wall-thickness economical duplex stainless steel continuous pipe for ultra-deep well injection

Abstract

The utility model relates to the technical field of alloy continuous pipes, in particular to a variable-wall-thickness economical duplex stainless steel continuous pipe for injection of an ultra-deep well, which comprises a continuous pipeline, a connecting pipeline, a mounting component, a connecting component, a fixing component and a sealing component, the mounting component is arranged at one end of the continuous pipeline, the connecting pipeline is arranged at one end of the continuous pipeline, and the fixing component is arranged at the other end of the continuous pipeline. In the using process of the alloy continuous pipe, in order to increase the tripping-in depth of the economical corrosion-resistant alloy continuous pipe, continuous wall thickness changing of the continuous pipe is achieved in a multi-section continuous wall thickness changing mode, and pipe column stress concentration caused by a single wall thickness changing section is completely avoided; the wall thickness dimensional tolerance of the variable wall thickness section is set to be larger than the rolled plate wall thickness dimensional tolerance and is within the range of two times of the rolled plate wall thickness dimensional tolerance, it is guaranteed that the rolled plate wall thickness changes evenly, by means of the design, the weight of the pipe column is reduced, cost is reduced, the tripping-in depth of the pipe column is increased, and the problem that the tensile property of the corrosion-resistant alloy continuous pipe is insufficient is completely solved; and the device can adapt to working conditions of deep wells and ultra-deep wells.

Description

TECHNICAL FIELD

[0001] The utility model relates to alloy continuous tube technical field especially uses a kind of variable wall thickness economic type duplex stainless steel continuous tube for super deep well injection. BACKGROUND

[0002] CCUS technology is generally applied to developed oil field, and the gas injection string is fully contacted with the injected gas. During the water-gas alternation process, the water and gas flow at different speeds, and the wellbore is in a gas-liquid coexistence state, which causes corrosion to the wellhead equipment and downhole string. With the increase of formation depth, the temperature and pressure change in a gradient, and CO2 dissolves in water, which easily causes local pitting corrosion, moss corrosion and mesa corrosion of the string (ordinary carbon steel) under high-temperature and high-pressure working conditions. The corrosion rate is as high as 5-7 mm / a. Currently, the use of corrosion-resistant alloy continuous tube instead of ordinary carbon steel oil pipe solves the problems of gas-tightness and insufficient corrosion resistance of the oil pipe.

[0003] During the actual use process, the conventional carbon steel is severely corroded during the CCUE-EOR injection process in the oil field site, and corrosion perforation is more likely to occur. The use of corrosion-resistant alloy continuous tube products is expensive, and there is a problem of inability to be widely applied in large quantities.

[0004] Therefore, in order to solve the problem of insufficient tensile property of the economic corrosion-resistant alloy continuous tube, a variable wall thickness economic type duplex stainless steel continuous tube for super deep well injection can be designed. When the alloy continuous tube is used, first, the installation assembly at one end of the continuous pipe is aligned with the connection assembly at one end of the connection pipe, to ensure that the holes on the side walls of the two are one-to-one corresponding. Then, the firm connection between the continuous pipe and the connection pipe can be realized through the fixing assembly. At the same time, the sealing performance of the pipe can be effectively improved through the sealing assembly. In addition, in order to increase the depth of the economic corrosion-resistant alloy continuous pipe, the continuous pipe is continuously changed in wall thickness in a multi-section continuous variable wall thickness manner, which completely avoids the stress concentration of the single variable wall thickness section, and the wall thickness size tolerance of the variable wall thickness section is set to be greater than the wall thickness size tolerance of the coiled plate to be within the range of two times the tolerance, to ensure that the wall thickness of the coiled plate changes uniformly. This design not only reduces the weight and cost of the string, but also increases the depth of the string, and completely solves the problem of insufficient tensile property of the economic corrosion-resistant alloy continuous tube, which can adapt to the working environment of deep well and super deep well. SUMMARY

[0005] In order to overcome the problem that the conventional carbon steel is severely corroded during the CCUE-EOR injection process in the oil field site, and corrosion perforation is more likely to occur, and the use of corrosion-resistant alloy continuous tube products is expensive, and there is a problem of inability to be widely applied in large quantities.

[0006] The utility model discloses a technical scheme for an economic duplex stainless steel continuous pipe with variable wall thickness for super-deep well injection, which comprises a continuous pipe, a connecting pipe, an installation assembly, a connecting assembly, a fixing assembly and a sealing assembly.

[0007] Preferably, when the alloy continuous pipe is in use, first, the installation assembly at one end of the continuous pipe is aligned with the connecting assembly at one end of the connecting pipe to ensure that the holes on the sidewalls of the two assemblies correspond to each other, then, the fixing assembly can be used to firmly connect the continuous pipe and the connecting pipe, and meanwhile, the sealing assembly can effectively improve the sealing performance of the pipe. In addition, to increase the depth of the economic corrosion-resistant alloy continuous pipe, the continuous pipe is continuously changed in wall thickness in a multi-section continuous variable wall thickness manner, which completely avoids the stress concentration of the pipe string caused by a single variable wall thickness section, and the wall thickness size tolerance of the variable wall thickness section is set to be greater than the wall thickness size tolerance of the coiled plate to within a range of two times the tolerance, thereby ensuring uniform change of the wall thickness of the coiled plate. This design not only reduces the weight of the pipe string and the cost, but also increases the depth of the pipe string and completely solves the problem of insufficient tensile performance of the economic corrosion-resistant alloy continuous pipe, and can be adapted to the working conditions of deep and super-deep wells.

[0008] Preferably, the installation assembly comprises an installation flange and an installation hole, the one end of the continuous pipe is provided with the installation flange, the sidewall of the installation flange is provided with the installation hole, and the installation hole is provided with multiple groups.

[0009] Preferably, the connecting assembly comprises a connecting flange and a connecting hole, the one end of the connecting pipe is provided with the connecting flange, the sidewall of the connecting flange is provided with the connecting hole, and the connecting hole is provided with multiple groups.

[0010] Preferably, the fixing assembly comprises a fixing bolt and a fixing nut, the connecting hole is provided with the fixing bolt, the one end of the fixing bolt is provided with the fixing nut, and the fixing nut is threadedly connected to the one end of the fixing bolt.

[0011] Preferably, the sealing assembly comprises an installation ring groove, the inner wall of the installation flange is provided with the installation ring groove, the installation ring groove is provided with two groups, and the other installation ring groove is provided on the inner wall of the connecting flange.

[0012] Preferably, the sealing assembly further comprises a sealing ring, and the installation ring groove is provided with the sealing ring.

[0013] The utility model has the advantages of:

[0014] When the alloy continuous pipe is in use, first, the installation assembly of one end of the continuous pipe is aligned with the connecting assembly of one end of the connecting pipe, the holes on the sidewalls of the two are one-to-one corresponding, then the fixed assembly can realize the firm connection between the continuous pipe and the connecting pipe, at the same time, the sealing assembly can effectively improve the sealing performance of the pipe, in addition, in order to increase the running depth of the economic corrosion-resistant alloy continuous pipe, the continuous pipe is realized to continuously change the wall thickness in a multi-section continuous wall thickness changing mode, the stress concentration of the pipe string caused by the single wall thickness changing section is completely avoided, the wall thickness size tolerance of the wall thickness changing section is set to be greater than the wall thickness size tolerance of the coiled plate to be within the tolerance range of the wall thickness size tolerance of the coiled plate, the uniform change of the wall thickness of the coiled plate is ensured, the pipe string weight is reduced, the cost is reduced, the running depth of the pipe string is increased, the problem of insufficient tensile property of the economic corrosion-resistant alloy continuous pipe is completely solved, and the deep well and ultra-deep well working environment can be adapted to. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 A first three-dimensional structure schematic view of the variable-wall-thickness economic duplex stainless steel continuous pipe for super-deep well injection is shown.

[0016] Figure 2 A first partial three-dimensional structure schematic view of the variable-wall-thickness economic duplex stainless steel continuous pipe for super-deep well injection is shown.

[0017] Figure 3 A second partial three-dimensional structure schematic view of the variable-wall-thickness economic duplex stainless steel continuous pipe for super-deep well injection is shown.

[0018] Figure 4 A third partial three-dimensional structure schematic view of the variable-wall-thickness economic duplex stainless steel continuous pipe for super-deep well injection is shown.

[0019] The reference signs are explained as follows: 1, continuous pipe; 2, connecting pipe; 101, installation flange; 102, installation hole; 201, connecting flange; 202, connecting hole; 301, fixed bolt; 302, fixed nut; 401, installation ring groove; 402, sealing ring. DETAILED DESCRIPTION

[0020] The utility model will be further explained in connection with the drawings and examples.

[0021] Please refer to Figures 1-4The utility model provides an embodiment: a kind of economic type duplex stainless steel continuous tube for super deep well injection with variable wall thickness, including continuous pipeline 1, connecting pipeline 2, installation assembly, connecting assembly, fixed assembly and sealing assembly, one end of continuous pipeline 1 is provided with installation assembly, one end of continuous pipeline 1 is provided with connecting pipeline 2, one end of connecting pipeline 2 is provided with connecting assembly, the inside of connecting assembly is provided with fixed assembly, and the inner wall of mounting flange plate 101 is provided with sealing assembly.

[0022] Please refer to Figure 2 Installation assembly includes mounting flange plate 101 and mounting hole 102, one end of continuous pipeline 1 is provided with mounting flange plate 101, mounting hole 102 is set up on the side wall of mounting flange plate 101, and mounting hole 102 is set up with multiple groups, and mounting flange plate 101 and mounting hole 102 can play the effect of auxiliary installation, connecting assembly includes connecting flange plate 201 and connecting hole 202, one end of connecting pipeline 2 is provided with connecting flange plate 201, connecting hole 202 is set up on the side wall of connecting flange plate 201, and connecting hole 202 is set up with multiple groups, and connecting flange plate 201 and connecting hole 202 can play the effect of auxiliary installation, fixed assembly includes fixed bolt 301 and fixed nut 302, fixed bolt 301 is provided in the inside of connecting hole 202, one end of fixed bolt 301 is provided with fixed nut 302, and fixed nut 302 is threadedly connected with one end of fixed bolt 301, and the firm connection between continuous pipeline 1 and connecting pipeline 2 is realized by fixed bolt 301 passing through the corresponding hole and being fastened with fixed nut 302.

[0023] Please refer to Figures 3-4 Sealing assembly includes mounting ring groove 401, and the inner wall of mounting flange plate 101 is provided with mounting ring groove 401, and mounting ring groove 401 is set up with two groups, and the other mounting ring groove 401 is set up on the inner wall of connecting flange plate 201, and mounting ring groove 401 can realize the installation effect of sealing ring 402, and sealing assembly further includes sealing ring 402, and the inside of mounting ring groove 401 is provided with sealing ring 402, and the sealing performance of pipeline can be effectively improved by sealing ring 402 on the inner wall of mounting flange plate 101 and connecting flange plate 201.

[0024] When alloy continuous tube is used, first, the mounting flange plate 101 of one end of continuous pipeline 1 is aligned with the connecting flange plate 201 of one end of connecting pipeline 2, ensures that mounting hole 102 and connecting hole 202 on the side wall of both are one-to-one correspondence, then, fixed bolt 301 passes through the corresponding hole and is fastened with fixed nut 302, realizes the firm connection between continuous pipeline 1 and connecting pipeline 2, simultaneously, the sealing performance of pipeline can be effectively improved by sealing ring 402 on the inner wall of mounting flange plate 101 and connecting flange plate 201,

[0025] In addition, in order to increase the running depth of the economic corrosion-resistant alloy continuous pipe 1, the continuous pipe 1 is continuously changed in thickness in a multi-section manner, stress concentration of the pipe string caused by a single variable thickness section is completely avoided, the thickness size tolerance of the variable thickness section is set to be greater than the thickness size tolerance of the coiled plate to be within a range of two times of the thickness size tolerance, and uniform change of the thickness of the coiled plate is ensured, so that the pipe string weight is reduced, the cost is lowered, the running depth of the pipe string is increased, the problem of insufficient tensile property of the economic corrosion-resistant alloy continuous pipe is completely solved, and the deep well and ultra-deep well working environment can be adapted.

[0026] Through the above steps, when the alloy continuous pipe is used, first, the mounting assembly at one end of the continuous pipe 1 is aligned with the connecting assembly at one end of the connecting pipe 2, the holes on the side walls of the two are ensured to be one-to-one corresponding, then the fixed assembly can be used to realize firm connection between the continuous pipe 1 and the connecting pipe 2, meanwhile, the sealing assembly can effectively improve the sealing performance of the pipe, in addition, in order to increase the running depth of the economic corrosion-resistant alloy continuous pipe 1, the continuous pipe 1 is continuously changed in thickness in a multi-section manner, stress concentration of the pipe string caused by a single variable thickness section is completely avoided, the thickness size tolerance of the variable thickness section is set to be greater than the thickness size tolerance of the coiled plate to be within a range of two times of the thickness size tolerance, and uniform change of the thickness of the coiled plate is ensured, so that the pipe string weight is reduced, the cost is lowered, the running depth of the pipe string is increased, the problem of insufficient tensile property of the economic corrosion-resistant alloy continuous pipe is completely solved, and the deep well and ultra-deep well working environment can be adapted.

[0027] The embodiments of the utility model are described in detail above in combination with the drawings, but the utility model is not limited to the above-mentioned embodiments, and various changes can be made within the knowledge of those skilled in the art without departing from the purpose of the utility model.

Claims

1. An economical dual-phase stainless steel continuous pipe with variable wall thickness for ultra-deep well injection, comprising a continuous pipe (1), characterized in that: It also includes connecting pipe (2), mounting assembly, connecting assembly, fixing assembly and sealing assembly, one end of continuous pipe (1) is provided with mounting assembly, one end of continuous pipe (1) is provided with connecting pipe (2), one end of connecting pipe (2) is provided with connecting assembly, the inside of connecting assembly is provided with fixing assembly, the inner wall of mounting flange (101) is provided with sealing assembly.

2. The variable wall thickness economic duplex stainless steel coiled tubing for ultra-deep well injection according to claim 1, characterized in that: The mounting assembly comprises mounting flange (101) and mounting hole (102), one end of continuous pipe (1) is provided with mounting flange (101), the sidewall of mounting flange (101) is provided with mounting hole (102), and mounting hole (102) is provided with multiple groups.

3. The variable wall thickness economic duplex stainless steel coiled tubing for ultra-deep well injection according to claim 1, characterized in that: The connecting assembly comprises connecting flange (201) and connecting hole (202), one end of connecting pipe (2) is provided with connecting flange (201), the sidewall of connecting flange (201) is provided with connecting hole (202), and connecting hole (202) is provided with multiple groups.

4. The variable wall thickness economic duplex stainless steel coiled tubing for ultra-deep well injection according to claim 3, characterized in that: The fixing assembly comprises fixing bolt (301) and fixing nut (302), the inside of connecting hole (202) is provided with fixing bolt (301), one end of fixing bolt (301) is provided with fixing nut (302), and fixing nut (302) is threadedly connected with one end of fixing bolt (301).

5. The variable wall thickness economic duplex stainless steel coiled tubing for ultra-deep well injection according to claim 3, characterized in that: The sealing assembly comprises mounting ring groove (401), the inner wall of mounting flange (101) is provided with mounting ring groove (401), mounting ring groove (401) is provided with two groups, and the other mounting ring groove (401) is provided on the inner wall of connecting flange (201).

6. The variable wall thickness economic duplex stainless steel coiled tubing for ultra-deep well injection according to claim 5, characterized in that: The sealing assembly further comprises sealing ring (402), and the inside of mounting ring groove (401) is provided with sealing ring (402).

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