A jacketed coiled tubing repair device and a coiled tubing repair method based thereon

Abstract

The present invention discloses a jacket-type continuous oil tubing repair device and a continuous oil tubing repair method based thereon. The repair device includes a continuous oil tubing section, a connector, and a heating coil. The connector is made of a nickel-titanium shape memory alloy, and its material strength is greater than or equal to that of the continuous oil tubing material. After the shape memory is restored, the inner diameter is smaller than the outer diameter of the continuous oil tubing section, and the wall thickness is the same as the wall thickness of the continuous oil tubing section. During repair, the connector is first expanded and deformed at a low temperature to facilitate the insertion of two continuous oil tubing sections into the connector from both ends. The heating coil heats the connector above the transition temperature after the continuous oil tubing section is inserted, keeps the heat, and restores the connector to a state above the transition temperature. The continuous oil tubing is repaired through contact pressure. The continuous oil tubing repaired by this process has high reliability, saves continuous oil tubing costs, and promotes the on-site application and development of continuous oil tubing.

Description

Technical Field

[0001] The present invention belongs to the technical field of oil and gas field exploration and development, and in particular relates to a jacket-type coiled tubing repair device and a coiled tubing repair method based thereon. Background Art

[0002] During drilling operations in oil and gas exploration and development, coiled tubing (CCT) is widely used in drilling and completion operations such as fracturing and sand flushing. Coiled tubing, also known as flexible tubing, is made of low-carbon alloy steel and offers excellent flexibility. A single roll can be several kilometers long. It can replace conventional tubing in many operations. Coiled tubing equipment features pressurized operation and continuous tripping, and is compact, with fast cycle times and low costs. However, since CTUs are formed from a single, integral pipe, traditional welding repair methods are complex and demanding when localized damage or fractures occur during use. Different pipe materials require different welding wires, making weld quality difficult to guarantee. Summary of the Invention

[0003] In order to overcome the shortcomings of the above-mentioned prior art, the purpose of the present invention is to provide a jacketed coiled tubing repair device and a coiled tubing repair method based thereon, so as to solve the technical problems in the prior art such as complex repair methods, high requirements, and the need to use different welding wires.

[0004] In order to achieve the above object, the present invention adopts the following technical solutions:

[0005] The present invention discloses a jacketed coiled tubing repair device, comprising a connector, wherein a heating coil is provided on the outside of the connector and a first coiled tubing section and a second coiled tubing section are jacketed on the inside of the connector;

[0006] The first coiled tubing section and the second coiled tubing section have the same material, outer diameter and wall thickness;

[0007] The connecting piece is in the shape of a circular ring and is made of a one-way shape memory alloy material;

[0008] A plurality of first negative-angle serrated grooves and second negative-angle serrated grooves are respectively provided on both sides of the inner surface of the connecting piece; the first negative-angle serrated grooves and the second negative-angle serrated grooves have the same shape and are in opposite directions.

[0009] Furthermore, the transition temperature of the connecting piece is greater than or equal to 45° C., and the length is 80 to 150 mm.

[0010] Furthermore, the inner diameter of the connecting piece after deformation below the transition temperature is 0.2 to 0.4 mm larger than the outer diameters of the first and second continuous oil tubing sections; after the connecting piece recovers its memory, the inner diameter of the connecting piece is 0.3 to 0.5 mm smaller than the outer diameters of the continuous oil tubing sections, and the wall thickness is the same as the wall thickness of the first and second continuous oil tubing sections; the material strength of the connecting piece after recovering its memory is greater than or equal to the material strength of the first and second continuous oil tubing sections.

[0011] Furthermore, the number of the first negative-angle sawtooth grooves and the second negative-angle sawtooth grooves are 3-7 respectively.

[0012] Furthermore, the negative angles of the first negative angle serrated groove and the second negative angle serrated groove are -3° to -5°, the slope angle is 30°, the groove depth is 5 to 10% of the wall thickness of the connector, the tooth top width is 1-2 mm, and the tooth bottom width is 2-3 mm.

[0013] The present invention also discloses a method for repairing a coiled tubing based on the above-mentioned outer jacket type coiled tubing repair device, comprising the following steps:

[0014] First, the connector is deformed below the transition temperature, and the first and second coiled tubing sections are respectively inserted into the connector, with the insertion depth being 1 / 2 of the connector length. The connector is then heated using a heating coil and kept warm to obtain the repaired coiled tubing.

[0015] Furthermore, the heating temperature is 50-65°C, and the insulation time is 15-20 minutes.

[0016] The present invention also discloses a repaired coiled tubing obtained by the above repair method. The connection strength of the repaired coiled tubing at the connector is greater than 80% of the connection strength of the tubing body, and the sealing strength is greater than 85% of the internal pressure resistance strength of the tubing body.

[0017] Furthermore, the operating temperature of the repaired coiled tubing is -20°C to 220°C.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] The present invention discloses a jacketed coiled tubing repair device, which uses a connector made of a one-way memory alloy material as a connecting material. By heating it through a heating coil, the connector can achieve dimensional expansion below the transition temperature, which facilitates the insertion of two sections of the coiled tubing into the connector from both ends. The heating coil heats the connector above the transition temperature after the inserted coiled tubing sections, keeps it warm, and restores the connector to a state above the transition temperature. The coiled tubing is repaired through contact pressure. During the repair, no welding equipment is required, nor is heat treatment required for the weld of the welded repaired coiled tubing. The device has a simple structure, convenient construction, and high reliability.

[0020] Furthermore, a number of negative-angle serrated grooves are provided on both sides of the inner surface of the connector, which can divide the inner surface of the connector into multiple small annular contact surfaces for contacting the continuous oil tubing section, thereby increasing the contact force and sealing effect between the connector and the continuous oil tubing section.

[0021] The present invention also discloses a method for repairing a coiled tubing using the jacket-type coiled tubing repair device. The method is simple and easy to operate, does not require additional welding equipment, has low cost and high reliability.

[0022] The repaired coiled tubing obtained by the above-mentioned coiled tubing repair method has a performance at the joint that reaches more than 80% of the pipe body, which can effectively realize the reuse of the coiled tubing, save the cost of the coiled tubing, and promote the on-site application and development of the coiled tubing. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a schematic structural diagram of a jacket-type coiled tubing repair device according to the present invention;

[0024] Figure 2 This is a schematic diagram of the connector structure of the present invention;

[0025] Figure 3 This is a schematic structural diagram of a negative angle serrated groove in a connector according to the present invention;

[0026] Among them: 1-first continuous oil pipe section; 2-second continuous oil pipe section; 3-connecting piece; 31-first negative angle serrated groove; 32-second negative angle serrated groove; 4-heating coil. DETAILED DESCRIPTION

[0027] To facilitate understanding of the features and effects of the present invention by those skilled in the art, the following provides a general description and definition of the terms and expressions used in the specification and claims. Unless otherwise indicated, all technical and scientific terms used herein have the ordinary meanings as understood by those skilled in the art regarding the present invention. In the event of conflict, the definitions in this specification shall prevail.

[0028] The theories or mechanisms described and disclosed herein, whether correct or incorrect, should not limit the scope of the present invention in any way, that is, the present invention can be implemented without being limited by any specific theory or mechanism.

[0029] Herein, all features such as values, amounts, amounts, and concentrations defined in numerical ranges or percentage ranges are for brevity and convenience only. Accordingly, the description of numerical ranges or percentage ranges should be considered to include and specifically disclose all possible subranges and individual values ​​within the range (including integers and fractions).

[0030] In this document, unless otherwise specified, “include,” “including,” “contains,” “has” or similar terms cover the meanings of “consisting of” and “mainly consisting of,” for example, “A includes a” covers the meanings of “A includes a and other” and “A only includes a.”

[0031] In this document, for the sake of brevity, not all possible combinations of the various technical features in each embodiment or example are described. Therefore, as long as there are no contradictions in the combination of these technical features, the various technical features in each embodiment or example can be combined in any way, and all possible combinations should be considered to be within the scope of this specification.

[0032] Below in conjunction with specific embodiment, further set forth the present invention.Should be understood that these embodiments are only used to illustrate the present invention and are not used in limiting the scope of the present invention.In addition, should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms fall equally within the scope limited by the appended claims of the application.

[0033] The following examples were prepared using conventional instruments and equipment in the art. Experimental methods in the following examples, where specific conditions are not specified, were generally performed under conventional conditions or according to the conditions recommended by the manufacturer. The various raw materials used in the following examples, unless otherwise specified, were conventional commercially available products, with specifications conventional in the art. In the present specification and the following examples, unless otherwise specified, "%" indicates percentage by weight, "part" indicates parts by weight, and "ratio" indicates weight ratio.

[0034] Example 1

[0035] A jacketed coiled tubing repair device includes a connector 3 made of nickel-titanium shape memory alloy, a heating coil 4 disposed on the exterior of the connector 3, and a first coiled tubing segment 1 and a second coiled tubing segment 2 sheathed within the connector 3. The first coiled tubing segment 1 and the second coiled tubing segment 2 have the same material, outer diameter, and wall thickness.

[0036] The connector 3 is annular, has a transition temperature of 45°C, and is 110 mm long. Its inner diameter above the transition temperature (after memory recovery) is 0.3 mm smaller than the outer diameter of the coiled tubing section. Before coiled tubing repair, the connector 3 undergoes expansion and deformation below the transition temperature. After deformation, its inner diameter is 0.4 mm larger than the outer diameter of the coiled tubing section, and its wall thickness is the same as that of the coiled tubing section. After memory recovery, the material strength of the connector 3 is greater than or equal to that of the coiled tubing section 1.

[0037] like Figure 2 and Figure 3 As shown, a plurality of negative-angle serrated grooves are processed on both sides of the inner surface of the connecting member 3. The first negative-angle serrated groove 31 and the second negative-angle serrated groove 32 on the left and right sides have the same shape and are opposite in direction. There are 5 grooves; the negative angle is -5°, the slope angle is 30°, the groove depth is 8% of the wall thickness, the tooth top width is 1.5 mm, and the tooth bottom width is 2.5 mm.

[0038] Example 2

[0039] A jacketed coiled tubing repair device includes a connector 3 made of nickel-titanium shape memory alloy, a heating coil 4 disposed on the exterior of the connector 3, and a first coiled tubing segment 1 and a second coiled tubing segment 2 sheathed within the connector 3. The first coiled tubing segment 1 and the second coiled tubing segment 2 have the same material, outer diameter, and wall thickness.

[0040] The connector 3 is annular, has a transition temperature of 50°C, and is 90 mm long. Its inner diameter above the transition temperature (after memory restoration) is 0.4 mm smaller than the outer diameter of the coiled tubing segment. Before coiled tubing repair, the connector 3 undergoes expansion and deformation below the transition temperature. After deformation, its inner diameter is 0.25 mm larger than the outer diameter of the coiled tubing segment, and its wall thickness is the same as that of the coiled tubing segment. After memory restoration, the material strength of the connector 3 is greater than or equal to that of the coiled tubing segment 1.

[0041] like Figure 2 and Figure 3 As shown, a plurality of negative-angle serrated grooves are processed on both sides of the inner surface of the connecting member 3. The first negative-angle serrated groove 31 and the second negative-angle serrated groove 32 on the left and right sides have the same shape and are opposite in direction. There are three grooves; the negative angle is -4°, the slope angle is 30°, the groove depth is 5% of the wall thickness, the tooth top width is 1 mm, and the tooth bottom width is 2 mm.

[0042] Example 3

[0043] A jacketed coiled tubing repair device includes a connector 3 made of nickel-titanium shape memory alloy, a heating coil 4 disposed on the exterior of the connector 3, and a first coiled tubing segment 1 and a second coiled tubing segment 2 sheathed within the connector 3. The first coiled tubing segment 1 and the second coiled tubing segment 2 have the same material, outer diameter, and wall thickness.

[0044] The connector 3 is annular, has a transition temperature of 60°C, and is 80 mm long. Its inner diameter above the transition temperature (after memory restoration) is 0.5 mm smaller than the outer diameter of the coiled tubing segment. Before coiled tubing repair, the connector 3 undergoes expansion and deformation below the transition temperature. After deformation, its inner diameter is 0.2 mm larger than the outer diameter of the coiled tubing segment, and its wall thickness is the same as that of the coiled tubing segment. After memory restoration, the material strength of the connector 3 is greater than or equal to that of the coiled tubing segment 1.

[0045] like Figure 2 and Figure 3 As shown, a plurality of negative-angle serrated grooves are processed on both sides of the inner surface of the connecting member 3. The first negative-angle serrated groove 31 and the second negative-angle serrated groove 32 on the left and right sides have the same shape and are opposite in direction. There are 6 grooves; the negative angle is -3°, the slope angle is 30°, the groove depth is 7% of the wall thickness, the tooth top width is 2 mm, and the tooth bottom width is 2.5 mm.

[0046] Example 4

[0047] A jacket-type coiled tubing repair device differs from Example 1 in that the length of the connecting piece 3 is 150 mm, the number of first negative-angle serrated grooves 31 and second negative-angle serrated grooves 32 on the left and right sides is 7; the negative angle is -3°, the groove depth is 10% of the wall thickness, the tooth top width is 2 mm, and the tooth bottom width is 3 mm. The remaining components and materials are the same as those in Example 1.

[0048] Application Example 1

[0049] The outer jacket type coiled tubing repair device of Example 1 is used to perform continuous related repair, including the following steps:

[0050] The first coiled tubing section 1 and the second coiled tubing section 2 were respectively inserted into the connector 3 to a depth of 1 / 2 the length of the connector 3. The connector 3 was then heated using the heating coil 4 at a temperature of 60°. After the temperature was maintained for 19 minutes, the coiled tubing repair was completed.

[0051] The connection strength of the repaired coiled tubing at the connector 3 is greater than 80% of the tensile strength of the coiled tubing section 1 , and the sealing strength is greater than 85% of the internal pressure resistance of the coiled tubing section 1 .

[0052] like Figure 1As shown in the figure, the operating conditions of the repaired coiled tubing are -20℃~220℃.

[0053] Application Example 2

[0054] The outer jacket type coiled tubing repair device of Example 1 is used to perform continuous related repair, including the following steps:

[0055] The first coiled tubing section 1 and the second coiled tubing section 2 are respectively inserted into the connector 3, with the insertion depth being 1 / 2 of the length of the connector 3. The connector 3 is then heated using the heating coil 4 at a temperature of 65°. After keeping the temperature for 20 minutes, the coiled tubing is repaired.

[0056] Application Example 3

[0057] The outer jacket type coiled tubing repair device of Example 3 is used to perform continuous related repair, including the following steps:

[0058] The first coiled tubing section 1 and the second coiled tubing section 2 are respectively inserted into the connector 3 to a depth of 1 / 2 the length of the connector 3. The connector 3 is then heated using the heating coil 4 at a temperature of 55°. After the temperature is maintained for 16 minutes, the coiled tubing repair is completed.

[0059] Application Example 4

[0060] The outer jacket type coiled tubing repair device of Example 4 is used to perform continuous related repair, including the following steps:

[0061] The first coiled tubing section 1 and the second coiled tubing section 2 are respectively inserted into the connector 3, with the insertion depth being 1 / 2 of the length of the connector 3. The connector 3 is then heated using the heating coil 4 at a temperature of 50°. After keeping the temperature for 15 minutes, the coiled tubing is repaired.

[0062] The coiled tubing repaired by the above implementation method has high reliability, and the performance of the joint reaches more than 80% of the tubing body, which can effectively realize the reuse of the coiled tubing, save the cost of the coiled tubing, and promote the field application and development of the coiled tubing.

[0063] The above content is only for explaining the technical idea of ​​the present invention and cannot be used to limit the protection scope of the present invention. Any changes made on the basis of the technical solution in accordance with the technical idea proposed by the present invention shall fall within the protection scope of the claims of the present invention.

Claims

1. A method for repairing a coiled tubing using a jacketed coiled tubing repair device, characterized in that: The following steps are involved: First, the connector (3) is deformed below the transition temperature, and then the first continuous oil pipe section (1) and the second continuous oil pipe section (2) are respectively inserted into the connector (3), and the insertion depth is respectively 1 / 2 of the length of the connector (3), and then the connector (3) is heated by a heating coil (4). After heat preservation, a repaired continuous oil pipe is obtained; The heating temperature is 50-65°C and the holding time is 15-20 minutes; The connection strength of the repaired coiled tubing at the connector (3) is greater than 80% of the connection strength of the tubing body, and the sealing strength is greater than 85% of the internal pressure resistance strength of the tubing body; The jacket-type continuous oil pipe repair device comprises a connecting piece (3), wherein a heating coil (4) is provided on the outside of the connecting piece (3) and a first continuous oil pipe section (1) and a second continuous oil pipe section (2) are jacketed on the inside. The first continuous oil tubing section (1) and the second continuous oil tubing section (2) have the same material, outer diameter and wall thickness; The connecting piece (3) is in the shape of a circular ring and is made of a one-way shape memory alloy material; A plurality of first negative angle sawtooth grooves (31) and second negative angle sawtooth grooves (32) are respectively provided on both sides of the inner surface of the connecting member (3); the first negative angle sawtooth grooves (31) and the second negative angle sawtooth grooves (32) have the same shape and are in opposite directions; The negative angles of the first negative angle sawtooth groove (31) and the second negative angle sawtooth groove (32) are -3° to -5°, the slope angle is 30°, the groove depth is 5% to 10% of the wall thickness of the connecting member (3), the tooth top width is 1-2 mm, and the tooth bottom width is 2-3 mm.

2. The coiled tubing repair method using a jacketed coiled tubing repair device according to claim 1, characterized in that: The transition temperature of the connecting piece (3) is greater than or equal to 45°C, and the length is 80-150 mm.

3. The coiled tubing repair method using a jacketed coiled tubing repair device according to claim 1, characterized in that: The inner diameter of the connecting piece (3) after deformation below the transition temperature is 0.2-0.4 mm larger than the outer diameters of the first continuous oil pipe section (1) and the second continuous oil pipe section (2); after the connecting piece (3) recovers its memory, the inner diameter of the connecting piece (3) is 0.3-0.5 mm smaller than the outer diameter of the continuous oil pipe section (1), and the wall thickness is the same as the wall thickness of the first continuous oil pipe section (1) and the second continuous oil pipe section (2); the material strength of the connecting piece (3) after recovering its memory is greater than or equal to the material strength of the first continuous oil pipe section (1) and the second continuous oil pipe section (2).

4. The coiled tubing repair method using a jacketed coiled tubing repair device according to claim 1, characterized in that: The number of the first negative-angle sawtooth grooves (31) and the second negative-angle sawtooth grooves (32) is 3-7 respectively.

5. The coiled tubing repair method using a jacketed coiled tubing repair device according to claim 1, characterized in that: The operating temperature of the repaired coiled tubing is -20~220℃.

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