Repair device and repair method for casing pipe

Abstract

The invention provides a repair device for a casing pipe, which comprises a pipe column arranged in the casing pipe and a repair mechanism sleeved outside the pipe column, the repair mechanism comprises a first repair part and a second repair part arranged on the downstream of the first repair part, a deformation section is arranged on the inner wall of the casing pipe, and the deformation section is arranged on the inner wall of the casing pipe. The first repairing part and the second repairing part are each provided with a plurality of protrusions used for milling the deformation section. According to the method, the deformed section of the sleeve can be repaired step by step, so that staged conservative milling work is carried out on the deformed section of the sleeve, and the inner wall of the sleeve is protected to the maximum extent. In addition, the invention further provides a repairing method.

Description

Technical Field

[0001] The present invention relates to the technical field of casing repair, and in particular to a casing repair device and a casing repair method. Background Art

[0002] At present, the conventional method for treating casing deformation in oil and gas wells in oil and gas fields is to use a downhole milling cone tool string to lift and lower the string, thereby rotating and milling the casing deformation position to repair the casing deformation.

[0003] In the prior art, conventional milling cone tool strings have the following problems: First, the milling cone tool is usually a single-stage milling tool, so the stability is poor when performing milling work in the casing, so it is very easy to cause the casing to "open windows", thereby causing well leakage; second, the milling cone tool is very easy to expand the diameter of the casing, thereby causing downhole debris to be retained, the sealing device to fail or the sealing is ineffective, and then causing problems such as hanging and getting stuck in the later tubing string; third, when the tubing string is lifted or lowered, it is very easy to get stuck or the drill is stuck, thereby causing downhole accidents.

[0004] Therefore, it is desired in the art to provide a repair device for casing to solve the above technical problems. Summary of the invention

[0005] The purpose of the present invention is to provide a repair device for casing, which realizes the purpose of repairing the deformed section of the casing step by step through the first repair part and the second repair part, thereby achieving the conservative milling work of the deformed section of the casing in stages to protect the inner wall of the casing to the maximum extent, so as to further avoid the risk of drill sticking. In addition, a repair method is also provided.

[0006] According to a first aspect of the present invention, there is provided a repair device for a casing, comprising a pipe string for being arranged in the casing, and

[0007] A repair mechanism sleeved outside the pipe column comprises a first repair component and a second repair component arranged downstream of the first repair component.

[0008] Wherein, a deformation section is provided on the inner wall of the sleeve, and a plurality of protrusions for milling the deformation section are provided on both the first repair component and the second repair component.

[0009] In one embodiment, the first repair component and the second repair component are both configured in a tapered form.

[0010] In one embodiment, a guide groove for guiding foreign matter in the sleeve is provided on both the first repair component and the second repair component, and the guide groove is configured as a spiral channel.

[0011] In one embodiment, a plurality of the protrusions are spirally arranged on the outer walls of the first repair member and the second repair member and are located between adjacent diversion grooves, and an included angle of 30° to 45° is formed between the extending direction of the protrusions and the central line direction of the pipe string.

[0012] In one embodiment, the maximum diameter of the first repair member is larger than the maximum diameter of the second repair member, and the maximum diameter of the first repair member is equal to the inner diameter of the casing.

[0013] In one embodiment, the repair mechanism further includes pressure sensors that are spirally arranged on the first repair member and the second repair member and are used to receive the deformation signals of the deformed section.

[0014] In one embodiment, first chamfers configured as circular arcs are provided at both ends of the first repair member; second chamfers configured as circular arcs are provided at both ends of the second repair member.

[0015] In one embodiment, the repair mechanism further includes first limit seats provided at both ends of the first repair member and used for adapting to the first chamfers, and second limit seats provided at both ends of the second repair member and used for adapting to the second chamfers.

[0016] In one embodiment, a driving member for allowing the repair mechanism to rotate unidirectionally is provided at the upper end surface of the pipe string.

[0017] According to a second aspect of the present invention, there is provided a repair method using the repair device as described above, including the following steps:

[0018] S1. Put the assembled repair device into the casing.

[0019] S2. Initially mill the deformed section on the casing through the protrusions on the second repair member until the second repair member passes through the deformed section.

[0020] S3. Continue to descend, and secondarily mill the deformed section through the protrusions on the first repair member until the first repair member passes through the deformed section, thereby repairing the casing.

[0021] Compared with the prior art, the advantages of the present invention are as follows:

[0022] Firstly, the present invention realizes the purpose of gradually repairing the deformed section of the casing through the first repair member and the second repair member, thereby achieving a phased and conservative milling operation on the deformed section of the casing to protect the inner wall of the casing to the greatest extent and further avoiding the risk of sticking the drill.

[0023] In addition, both the first repair part and the second repair part of the present invention are arranged in an inverted cone structure, which is beneficial to improving the repair efficiency and quality, so that the repaired casing can have a clean and unobstructed working environment, and ensure that the subsequent packer can be successfully set.

[0024] Second, through the pressure sensors spirally arranged on the first repair part and the second repair part, the present invention can sense the deformation signal of the casing and transmit it to the ground for the operators to timely understand the deformation and repair conditions of the deformed section of the casing, and then can more easily control the changes of parameters such as drilling pressure and torque to further improve the repair ability of the casing. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The present invention will be described in detail below with reference to the drawings. In the drawings:

[0026] Figure 1 Schematically shows the structure of the repair device for the casing according to the present invention;

[0027] Figure 2 Schematically shows the first repair stage of the repair device for the casing according to the present invention;

[0028] Figure 3 Schematically shows the second repair stage of the repair device for the casing according to the present invention;

[0029] Figure 4 Schematically shows the third repair stage of the repair device for the casing according to the present invention.

[0030] In the drawings, the same components are denoted by the same reference numerals. The drawings are not drawn to actual scale. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0031] In order to make the technical solutions and advantages of the present invention clearer, the exemplary embodiments of the present invention will be further described in detail below with reference to the drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than an exhaustive list of all embodiments. And without conflict, the embodiments in the present invention and the features in the embodiments can be combined with each other.

[0032] In the description of the present invention, it should be understood that the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features.

[0033] In the present invention, unless otherwise clearly specified or limited, terms such as "installation", "connection", "linkage", "fixation" shall be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection or an electrical connection; it may be a direct connection or an indirect connection through an intermediate medium, and it may be the communication inside two components.

[0034] In the present invention, the directional terms "upstream" or "above" or similar terms refer to the direction close to the wellhead, that is, Figure 1 the top direction in Figure 1 . The directional terms "downstream" or "below" or similar terms refer to the direction away from the wellhead, that is,

[0035] the bottom direction in

[0036] For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0036] The present invention will be further described below with reference to the accompanying drawings.

[0037] Figure 1 Schematically shows the structure of a repair device 100 for a casing according to the present invention;

[0038] Figure 2 Schematically shows the first repair stage of a repair device 100 for a casing according to the present invention;

[0039] Figure 3 Schematically shows the second repair stage of a repair device 100 for a casing according to the present invention;

[0040] Figure 4 Schematically shows the third repair stage of a repair device 100 for a casing according to the present invention.

[0041] As Figure 1 shown, according to the first aspect of the present invention, there is provided a repair device 100 for a casing, which includes a pipe string 10 and a repair mechanism sleeved outside the pipe string 10. Among them, the repair mechanism includes a first repair member 101 and a second repair member 102. Preferably, the first repair member 101 is arranged upstream of the second repair member 102.

[0042] In an embodiment of the present invention, as Figures 2 - 4 shown, a deformed section 201 to be repaired and a flat section 202 with a standard inner diameter are formed on the inner wall of the casing 200.

[0043] Preferably, the repair device 100 for the casing is configured to be rotatably lowered into the casing 200, and can successively perform milling and expanding operations on the deformed section 201 in the casing 200 through the second repair member 102 and the first repair member 101 respectively, so as to achieve the purpose of repairing the casing 200, and its content will be introduced below.

[0044] In one embodiment, both the first repair member 101 and the second repair member 102 are configured in a conical form. Preferably, both the first repair member 101 and the second repair member 102 are configured in an inverted cone structure, so as to be able to perform milling and gradual expansion operations on the deformed section 201 in the casing 200, thereby ensuring that the deformed casing 200 can be effectively repaired and ensuring that the subsequent packer can be successfully set.

[0045] According to the present invention, as Figure 1 shown, a plurality of protrusions 21 are provided on the outer peripheral surfaces of both the first repair member 101 and the second repair member 102. Preferably, during the repair process, the protrusions 21 on the first repair member 101 and the second repair member 102 can contact the deformed section 201 in the casing 200 and further perform milling operations.

[0046] In addition, as the first repair member 101 and the second repair member 102 gradually move downstream, the repair mechanism can smoothly carry out the expansion operation in the deformed section 201 of the casing 200 until the first repair member 101 or the second repair member 102 successfully passes through the deformed section 201 of the casing 200, and its content will be introduced below.

[0047] In one embodiment, as Figure 1 shown, diversion grooves 22 are provided on both the first repair member 101 and the second repair member 102. Preferably, the diversion grooves 22 are configured as spiral channels, and the diversion grooves 22 can be spirally arranged on the outer walls of the first repair member 101 and the second repair member 102.

[0048] Preferably, in the present invention, the wellbore foreign matters generated by milling will be carried out through the diversion grooves 22, so as to ensure that the repaired casing 200 can have a smooth operation environment, thereby further improving the repair ability of the repair device 100 for the casing.

[0049] In one embodiment of the present invention, a plurality of protrusions 21 are respectively spirally arranged on the outer walls of the first repair member 101 and the second repair member 102. Preferably, the protrusions 21 are all located between adjacent diversion grooves 22.

[0050] Therefore, the foreign objects in the wellbore generated by the repair mechanism when milling the inner wall of the casing 200 with the protrusion 21 will smoothly fall into the diversion groove 22, so that they can be more easily taken out of the casing 200 through the diversion groove 22 after the repair is completed, further ensuring a clean and unobstructed working environment inside the casing 200.

[0051] In an embodiment of the present invention, an angle of 30° to 45° is formed between the extension direction of the protrusion 21 and the center line direction of the pipe string 10. Therefore, when the repair device 100 for the casing is performing repair work, the protrusions 21 on the first repair part 101 and the second repair part 102 can both mill the deformed section 201 inside the casing 200 with greater strength through the protrusions 21, thereby not only improving the repair speed of the repair device 100 for the casing, but also improving the repair quality of the deformed section 201 inside the casing 200 by the repair device 100 for the casing.

[0052] In the present invention, the protrusions 21 on the first repair part 101 and the second repair part 102 are both made of cemented carbide. In this way, the strength of the protrusions 21 is significantly improved, so that the protrusions 21 on the first repair part 101 and the second repair part 102 can more easily mill and expand the deformed section 201 inside the casing 200, further improving the repair quality of the deformed section 201 inside the casing 200 by the repair device 100 for the casing.

[0053] In the present invention, the first repair part 101 and the second repair part 102 are arranged at intervals in the axial direction, so as to be able to perform staged and conservative milling work on the deformed section 201 inside the casing 200, to protect the inner wall of the casing 200 to the greatest extent. Therefore, it can not only prevent the risk of sticking the drill, but also have the ability to evaluate the deformation degree of the casing 200, the content of which will be introduced below.

[0054] In a preferred embodiment of the present invention, the overall size of the first repair part 101 is larger than the overall size of the second repair part 102. Preferably, the volume of the protrusion 21 on the first repair part 101 is larger than the volume of the protrusion 21 on the second repair part 102, which helps the repair device 100 for the casing to perform staged and conservative milling work on the deformed section 201.

[0055] In an embodiment of the present invention, the maximum diameter of the first repair part 101 is larger than the maximum diameter of the second repair part 102. In other words, the diameter of the upper end surface of the first repair part 101 is larger than the diameter of the upper end surface of the second repair part 102. In this way, the repair device 100 for the casing can more easily perform staged and conservative milling work on the deformed section 201 inside the casing 200.

[0056] In one embodiment of the present invention, the maximum diameter of the first repair member 101 is equal to the inner diameter of the casing 200. Therefore, when the first repair member 101 can smoothly pass through the deformed section 201 inside the casing 200, the inner diameter of the deformed section 201 inside the casing 200 will be equal to the inner diameter of the flat section 202 inside the casing 200, thus successfully completing the repair work of the casing 200.

[0057] The following will introduce the repair process of the present invention in conjunction with Figures 2 - 4 as shown below:

[0058] After the repair device 100 for the casing is lowered into the casing 200, when the second repair member 102 approaches the deformed section 201 inside the casing 200, the pipe string 10 is rotated. The second repair member 102 will first use the smaller-diameter lower part to contact and mill the deformed section 201 inside the casing 200, and perform preliminary repair work.

[0059] Then, as the repair device 100 for the casing continues to be lowered, the diameter of the deformed section 201 inside the casing 200 will be preliminarily expanded under the action of the second repair member 102. Until the larger-diameter upper part of the second repair member 102 completely passes through the deformed section 201 inside the casing 200, the first-stage repair work of the present invention is completed.

[0060] The repair device 100 for the casing stops rotating and continues to move downstream. When the first repair member 101 approaches the deformed section 201 inside the casing 200, the pipe string 10 is rotated. The first repair member 101 will first use the smaller-diameter lower part to contact and mill the deformed section 201 inside the casing 200, and perform the final repair work.

[0061] Then, as the repair device 100 for the casing continues to be lowered, the diameter of the deformed section 201 inside the casing 200 will be finally expanded under the action of the first repair member 101. Until the larger-diameter upper part of the first repair member 101 completely passes through the deformed section 201 inside the casing 200, the second-stage repair work of the present invention is completed.

[0062] Preferably, after the second-stage repair work is completed, the inner diameter of the deformed section 201 inside the casing 200 will be equal to the inner diameter of the flat section 202 inside the casing 200, so as to ensure that a packer (not shown) can be successfully set inside the casing 200 during subsequent downhole operations.

[0063] In the present invention, through long-distance intermittent operations, namely the repair work in the first stage and the repair work in the second stage described above, the deformed section 201 within the casing 200 can be conservatively milled in stages, so as to maximize the protection of the inner wall of the casing 200. In this way, not only can the risk of sticking the drill in the casing 200 be prevented, but also the ability to evaluate the degree of deformation of the casing 200 can be achieved.

[0064] According to the present invention, as Figure 1 shown, the repair mechanism further includes a pressure sensor 23. Preferably, the pressure sensor 23 is arranged in a spiral manner on the first repair part 101 and the second repair part 102, so as to be able to sense the deformation signal of the casing 200 and transmit it to the ground for the operator to timely understand the deformation situation and repair situation of the deformed section 201 of the casing 200, thereby being able to more easily control the changes of parameters such as the drilling pressure and torque, and further improving the repair ability of the casing 200.

[0065] In addition, under the action of the pressure sensor 23, the repair device 100 for the casing can also have the ability to evaluate the degree of deformation of the casing 200 in real time.

[0066] In one embodiment, as Figure 1 shown, first chamfers 31 configured as circular arcs are provided at both ends of the first repair part 101, and second chamfers 32 configured as circular arcs are provided at both ends of the second repair part 102. Preferably, both the first repair part 101 and the second repair part 102 are configured to be more easily lowered into the casing 200 or lifted out of the casing 200 under the action of the first chamfers 31 and the second chamfers 32.

[0067] In this way, the working efficiency and working ability of the repair device 100 for the casing within the casing 200 are significantly improved, so as to further improve the repair ability of the casing 200.

[0068] In one embodiment, as Figure 1 shown, the repair mechanism further includes first limit seats 41 provided at both ends of the first repair part 101. Preferably, the first limit seats 41 can match with the first chamfers 31 provided at both ends of the first repair part 101 respectively and form a sealed connection, so as to more easily play a good limiting role on the first repair part 101.

[0069] In one embodiment, as Figure 1 shown, the repair mechanism further includes second limit seats 42 provided at both ends of the second repair part 102. Preferably, the second limit seats 42 can match with the second limit seats 42 provided at both ends of the second repair part 102 respectively and form a sealed connection, so as to more easily play a good limiting role on the second repair part 102.

[0070] In one embodiment, a driving member (not shown) is provided at the upper end face of the pipe string 10. Preferably, the driving member is configured to be able to drive the pipe string 10, as well as the first repair member 101 and the second repair member 102, to rotate unidirectionally in the casing 200, that is, to ensure that the repair device 100 for the casing can only perform rotational movement in a single direction in the casing 200. Thereby, the repair device 100 for the casing can perform efficient and safe repair work.

[0071] According to the second aspect of the present invention, there is provided a repair method using the repair device as described above, including the following steps:

[0072] S1. Connect the upper end face of the pipe string 10 to the driving member, and put the assembled repair device 100 for the casing into the casing 200.

[0073] S2. When the second repair member 102 approaches the deformed section 201 in the casing 200, rotate the pipe string 10, so as to initially mill the deformed section 201 on the casing 200 through the protrusion 21 on the second repair member 102 until the second repair member 102 smoothly passes through the deformed section 201.

[0074] Specifically, first, the second repair member 102 will first contact and mill the deformed section 201 in the casing 200 using the smaller-diameter lower part, and perform preliminary repair work; then, as the repair device 100 for the casing continues to be lowered, the diameter of the deformed section 201 in the casing 200 will be initially expanded under the action of the second repair member 102 until the larger-diameter upper part of the second repair member 102 completely passes through the deformed section 201 in the casing 200, that is, the repair work in the first stage of the present invention is completed.

[0075] S3. Continue to lower, when the first repair member 101 approaches the deformed section 201 in the casing 200, rotate the pipe string 10, so as to perform secondary milling on the deformed section 201 on the casing 200 through the protrusion 21 on the first repair member 101 until the first repair member 101 completely passes through the deformed section 201 to achieve the repair of the casing 200.

[0076] Specifically, first, the first repair member 101 will first contact and mill the deformed section 201 in the casing 200 using the smaller-diameter lower part, and perform final repair work; then, as the repair device 100 for the casing continues to be lowered, the diameter of the deformed section 201 in the casing 200 will be finally expanded under the action of the first repair member 101 until the larger-diameter upper part of the first repair member 101 completely passes through the deformed section 201 in the casing 200, that is, the repair work in the second stage of the present invention is completed.

[0077] Compared with the prior art, the advantages of the present invention are as follows:

[0078] First, the present invention realizes the purpose of gradually repairing the deformed section 201 of the casing 200 through the first repair member 101 and the second repair member 102, so as to achieve a phased and conservative milling operation on the deformed section 201 of the casing 200, to maximize the protection of the inner wall of the casing 200, and to further avoid the risk of sticking the drill.

[0079] In addition, both the first repair member 101 and the second repair member 102 of the present invention are arranged in an inverted cone structure, which is beneficial to improving the repair efficiency and repair quality, so that the repaired casing 200 can have a clean and unobstructed working environment, and ensure that the subsequent packer can be successfully set.

[0080] Second, through the pressure sensors 23 arranged spirally on the first repair member 101 and the second repair member 102, the present invention can sense the deformation signal of the casing 200 and transmit it to the ground for the operator to timely understand the deformation situation and repair situation of the deformed section 201 of the casing 200, and then it is easier to control the changes of parameters such as the drilling pressure and torque, so as to further improve the repair ability of the casing 200.

[0081] The above is only the preferred embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art can easily make changes or variations within the disclosure scope of the present invention, and such changes or variations should be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. A repair device for a casing, comprising: a pipe string (10) configured to be disposed within a casing (200), and a repair mechanism sleeved outside the pipe string (10), which includes a first repair member (101) and a second repair member (102) disposed downstream of the first repair member (101), wherein a deformed section (201) is provided on the inner wall of the casing (200), and a plurality of protrusions (21) for milling the deformed section (201) are provided on both the first repair member (101) and the second repair member (102).

2. The repair device for a casing according to claim 1, wherein: both the first repair member (101) and the second repair member (102) are configured in a conical form.

3. The repair device for a casing according to claim 2, wherein: flow guiding grooves (22) for guiding foreign matters within the casing (200) are provided on both the first repair member (101) and the second repair member (102), and the flow guiding grooves (22) are configured as spiral channels.

4. The repair device for a casing according to claim 3, wherein: the plurality of protrusions (21) are spirally arranged on the outer walls of the first repair member (101) and the second repair member (102) and are located between adjacent flow guiding grooves (22), and an angle of 30° to 45° is formed between the extending direction of the protrusions (21) and the central line direction of the pipe string (10).

5. The repair device for a casing according to claim 4, wherein: the maximum diameter of the first repair member (101) is larger than the maximum diameter of the second repair member (102), and the maximum diameter of the first repair member (101) is equal to the inner diameter of the casing (200).

6. The repair device for a casing according to claim 5, wherein: the repair mechanism further includes pressure sensors (23) spirally arranged on the first repair member (101) and the second repair member (102) and configured to receive deformation signals of the deformed section (201).

7. The repair device for a casing according to claim 6, wherein: first chamfers (31) configured as circular arcs are provided at both ends of the first repair member (101); second chamfers (32) configured as circular arcs are provided at both ends of the second repair member (102).

8. The repair device for a casing according to claim 7, wherein: the repair mechanism further includes first limit seats (41) provided at both ends of the first repair member (101) and configured to be adapted to the first chamfers (31), and second limit seats (42) provided at both ends of the second repair member (102) and configured to be adapted to the second chamfers (32).

9. The repair device for a casing according to claim 8, wherein: a driving member for allowing the repair mechanism to rotate unidirectionally is provided at the upper end surface of the pipe string (10).

10. A repair method using the repair device according to any one of claims 1 to 9, comprising the following steps: S1. Put the assembled repair device into the casing (200); S2. Initially mill the deformed section (201) on the casing (200) through the protrusion (21) on the second repair part (102) until the second repair part (102) passes through the deformed section (201); S3. Continue to move downward, and secondarily mill the deformed section (201) through the protrusion (21) on the first repair part (101) until the first repair part (101) passes through the deformed section (201), thereby repairing the casing (200).

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