Flexible cone casing expansion tool and casing expansion method

Abstract

The present invention discloses a flexible cone casing expansion tool and a casing expansion method. The tool includes an upper joint, a connecting outer shell, a reset spring compartment shell, a reset spring compartment cover, a hydraulic compartment shell, a flexible cone shrapnel, a spherical plug, a hydraulic oil pipe, a reset spring, a hydraulic cylinder piston shaft, a hydraulic cylinder body, and a sealing ring. When the present invention is used for side drilling operations in old wells, the part of the casing below the side drilling point is expanded and deformed, and a groove is formed on the casing to ensure that the cement solidification block used for plugging will not slip along the well wall. When the present invention reaches the predetermined position of the casing, hydraulic oil is pressed into the hydraulic cylinder body. Under the action of the hydraulic oil pressure, the hydraulic cylinder piston shaft drives the flexible cone shrapnel to undergo elastic deformation, forming an arch, and expanding the corresponding part of the casing. At the same time, the casing undergoes plastic deformation. When the expansion of the present invention is completed, the hydraulic oil pressure is released, and the hydraulic cylinder piston shaft is reset under the joint action of the reset spring and the flexible cone shrapnel, leaving a groove on the casing.

Description

Technical Field

[0001] The invention relates to a flexible cone casing expansion tool and belongs to the field of casing side drilling operations. Background Art

[0002] Sidetracking old wells is an important means of tapping the potential of various oil fields. It is more cost-effective than drilling new wells and can restore oil and gas production in old wells more effectively than conventional overhauls. Sidetracking old wells involves drilling a new wellbore by opening a window or milling a section at a specific depth within the original casing. These methods include inclined wells, directional wells, and horizontal wells. The most prominent feature of these two methods is that they can revive old wells and inactive wells, recover remaining oil, and restore production in older oil fields. They can fully utilize the original well site, the upper wellbore of the original well, and existing oil and gas pipelines, significantly saving investment. Currently, the cost of sidetracking a well is equivalent to 30% to 60% of the cost of drilling a new well, and the cost of horizontal wells is equivalent to 60% to 80% of the cost of drilling a new well.

[0003] Research on sidetracking string technology is still in its infancy in China, and mature supporting tools and technologies are not yet available. Especially for older wells where plugging is required below the sidetracking point, direct cement curing can create a risk of slippage due to the smoothness of the wellbore casing. A method is urgently needed to create grooves in the wellbore casing to prevent the slippage of the cement blocks used for plugging. Summary of the Invention

[0004] The present invention provides a flexible cone casing expansion tool and a casing expansion method, so as to achieve the purpose of placing the present invention in a casing position that needs to be expanded, starting a hydraulic pump, and causing the present invention to start expanding the well wall casing, forming a groove on the well wall casing, and making full preparations for using cement for solidification and sealing.

[0005] The present invention is achieved through the following technical solutions:

[0006] A flexible cone casing expansion tool comprises an upper joint, a connecting outer shell connected below the upper joint, a return spring bin housing connected below the connecting outer shell, a return spring bin cover on the return spring bin housing, a return spring installed in the return spring bin housing, a hydraulic cylinder piston shaft passing through the return spring, a hydraulic bin housing connected below the return spring bin housing, a hydraulic cylinder body installed in the hydraulic bin housing, a flexible cone shrapnel installed below the hydraulic bin housing, and a spherical plug below the hydraulic cylinder piston shaft; a channel is provided in the upper joint, the connecting outer shell, the return spring bin housing, and the hydraulic bin housing for passing a hydraulic oil pipe; a hydraulic oil pipe joint is provided below the hydraulic cylinder body; the upper end of the hydraulic oil pipe is connected to the lower part of the upper joint, and the lower end is connected to the hydraulic oil pipe joint below the hydraulic cylinder body.

[0007] During the research process, the inventors of this case discovered that the expansion degree of the flexible cone casing expansion tool required to achieve the optimal expansion deformation effect in wellheads of different diameters is different. The expansion size of the present invention has a range. The expansion degree within this range can be achieved by controlling the output pressure of the hydraulic pump to control the expansion degree of the flexible cone casing expansion tool. In this way, the present invention can adapt to wellheads of different diameters.

[0008] As can be seen, the present invention achieves expansion of the well casing, enabling its use in wellheads of varying diameters. This ensures the reliability of the plugging cement after curing, enabling continuous and efficient operation of the entire sidetracking process from an old well to a new one, thus filling a gap in the existing technology. The present invention allows for adequate pre-installation of the plugging cement, significantly reducing the difficulty of plugging and improving overall efficiency of sidetracking from an old well to a new one.

[0009] Those skilled in the art should understand that in this application, the term "up" and "down" refers to the direction toward the wellhead after the tool enters the well as the direction toward the bottom of the well.

[0010] Furthermore, a throttling chamber is provided inside the upper joint for connecting the hydraulic oil pipe and the main hydraulic oil circuit.

[0011] This solution allows the hydraulic oil pipe and the hydraulic oil main oil circuit to be connected on different axes, making it easy to move the hydraulic oil pipe to the side inside the flexible cone casing expansion tool, leaving the internal axis position of the flexible cone casing expansion tool for installing the hydraulic cylinder piston shaft.

[0012] Furthermore, the return spring chamber housing is provided with a limit baffle, a through hole with a diameter of 120 mm is opened in the center of the limit baffle, and a through hole of 50 mm is opened on the side of the limit baffle for passing the hydraulic oil pipe.

[0013] This solution allows the hydraulic oil pipe to pass through the limit baffle of the return spring chamber housing, so that the hydraulic oil pipe can successfully deliver the hydraulic oil to the hydraulic cylinder body.

[0014] Furthermore, the limit baffle allows the hydraulic cylinder piston shaft to pass through and can move axially freely with a range of motion of 350 mm; the return spring passing through the hydraulic cylinder piston shaft contacts the limit baffle, and the return spring cannot pass through the limit baffle.

[0015] This solution ensures that the piston shaft of the hydraulic cylinder can restore the initial position of the flexible cone casing expansion tool under the action of the elastic force of the return spring when the hydraulic pressure is released.

[0016] Furthermore, the middle part of the hydraulic cylinder piston shaft is the piston part, which is installed in the hydraulic cylinder body. Two slots are provided in the piston part for installing a sealing ring; a shoulder is provided on the upper part of the hydraulic cylinder piston shaft to limit the reset spring; a spherical plug is installed on the lower part of the hydraulic cylinder piston shaft.

[0017] This solution can ensure the sealing performance of the contact between the hydraulic cylinder body and the piston part of the hydraulic cylinder piston shaft, so that the overall hydraulic cylinder structure can work normally.

[0018] Furthermore, 10 flexible cone springs are installed under the hydraulic chamber housing, and the flexible cone springs will undergo elastic deformation when subjected to external forces.

[0019] The core of this solution is to utilize the arch formed by the elastic deformation of the flexible cone shrapnel under the action of force, and then produce an expansion effect.

[0020] Furthermore, when the hydraulic cylinder piston shaft is subjected to hydraulic pressure, it will undergo axial movement. At this time, the return spring begins to compress under the action of the shaft shoulder on the upper part of the hydraulic cylinder piston shaft and the limit baffle in the return spring chamber housing. When the hydraulic pressure decreases, the return spring rebounds to ensure that the hydraulic cylinder piston shaft returns to its initial position.

[0021] This proposal introduces the working principle of the return spring when the flexible cone casing expansion tool is working.

[0022] Furthermore, the lower part of the flexible cone spring is fixed to the hydraulic cylinder piston shaft through a spherical plug installed at the lower part of the hydraulic cylinder piston shaft; when the hydraulic cylinder piston shaft moves axially under hydraulic pressure, the flexible cone spring undergoes elastic deformation to form an arch; when 10 flexible cone springs undergo elastic deformation at the same time to form an arch, an expansion effect is exerted on the casing.

[0023] This solution introduces the working principle of the flexible cone shrapnel when the flexible cone casing expansion tool is working.

[0024] Furthermore, two outwardly protruding bosses are provided on the side surface of the hydraulic cylinder body, and two inner grooves matching the two outwardly protruding bosses on the side surface of the hydraulic cylinder body are also provided in the hydraulic chamber shell.

[0025] This solution ensures that the hydraulic cylinder body and the hydraulic tank housing will not rotate relative to each other after installation.

[0026] A method for using a flexible cone casing expansion tool in this application includes:

[0027] S1. Place the flexible cone casing expansion tool into the casing and move it to the location where the casing needs to be expanded;

[0028] S2. When the flexible cone casing expansion tool reaches the predetermined position, hydraulic oil is pressed into the hydraulic cylinder body. Under the action of the hydraulic oil pressure, the hydraulic cylinder piston shaft drives the flexible cone spring to elastically deform, forming an arch, expanding the corresponding part of the casing, and at the same time, the casing undergoes plastic deformation;

[0029] S3. When the flexible cone casing expansion tool has completed expansion, the hydraulic oil pressure is released. The hydraulic cylinder piston shaft returns to its initial position under the combined action of the return spring and the flexible cone spring. The flexible cone casing expansion tool returns to its initial state, leaving a groove in the casing. Repeat the above steps to expand the casing to the desired number of grooves. S4. Pause the hydraulic pump and remove the flexible cone casing expansion tool.

[0030] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0031] 1. The flexible cone casing expansion tool and casing expansion method of the present invention can make sufficient advance preparations for filling plugging cement, significantly reduce the difficulty of plugging, and improve the overall efficiency of sidetracking new wells in old wells.

[0032] 2. The flexible cone casing expansion tool and casing expansion method of the present invention are simple to operate, and technicians can operate them without special training.

[0033] 3. The flexible cone casing expansion tool and casing expansion method of the present invention have a simple structure, do not use electronic components, and have high reliability.

[0034] 4. The flexible cone casing expansion tool and casing expansion method of the present invention are ingeniously designed and utilize the elastic deformation of the flexible cone spring to produce an expansion effect. Compared with the traditional method of directly expanding by pushing out the extrusion block from the side, the expansion degree of the present invention can be adjusted, the expansion range is wider, and the expansion efficiency is higher.

[0035] 5. The flexible cone casing expansion tool and casing expansion method of the present invention can adapt to wellheads of different diameters by setting the output pressure of the hydraulic pump.

[0036] 6. The present invention provides a flexible cone casing expansion tool and a casing expansion method. After using the present invention, cement solidification and sealing can be used. Compared with other sealing methods, cement solidification and sealing are low-cost and easy to operate.

[0037] 7. The flexible cone casing expansion tool and casing expansion method of the present invention do not generate consumable materials when used, and have low use costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] The drawings described herein are used to provide a further understanding of the embodiments of the present invention, constitute a part of this application, and do not constitute a limitation of the embodiments of the present invention. In the drawings:

[0039] Figure 1 This is a schematic structural diagram of an initial state of a specific embodiment of the present invention;

[0040] Figure 2 This is a schematic structural diagram of an expanded state of a specific embodiment of the present invention;

[0041] Figure 3 A schematic diagram of a half-section structure of an initial state of a specific embodiment of the present invention;

[0042] Figure 4 It is a schematic diagram of a half-section structure of a specific embodiment of the present invention in an expanded state;

[0043] Figure 5 This is a schematic diagram of the flexible cone structure in the initial state of a specific embodiment of the present invention;

[0044] Figure 6 This is a schematic diagram of the flexible cone structure in an expanded state according to a specific embodiment of the present invention;

[0045] The marks and corresponding parts names in the accompanying drawings are: 1-upper joint, 2-connecting outer shell, 3-return spring chamber housing; 4-return spring chamber cover, 5-hydraulic chamber housing; 6-flexible cone spring, 7-spherical plug, 8-hydraulic oil pipe, 9-return spring, 10-hydraulic cylinder piston shaft, 11-hydraulic cylinder body, 12-sealing ring. DETAILED DESCRIPTION

[0046] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, other embodiments obtained by ordinary technicians in this field without making creative work are all within the scope of protection of the present invention.

[0047] A flexible cone casing expansion tool such as Figure 3As shown, it includes an upper joint 1, a connecting outer shell 2 connected to the bottom of the upper joint 1, a return spring bin shell 3 connected to the bottom of the connecting outer shell 2, a return spring bin cover 4 on the return spring bin shell 3, a return spring 9 installed in the return spring bin shell 3, a hydraulic cylinder piston shaft 10 passing through the return spring 9, a hydraulic bin shell 5 connected to the bottom of the return spring bin shell 3, a hydraulic cylinder body 11 installed in the hydraulic bin shell 5, a flexible cone shrapnel 6 installed under the hydraulic bin shell 5, and a spherical plug 7 under the hydraulic cylinder piston shaft 10; a channel is provided in the upper joint 1, the connecting outer shell 2, the return spring bin shell 3, and the hydraulic bin shell 5 for passing a hydraulic oil pipe 8; a hydraulic oil pipe joint is provided under the hydraulic cylinder body 11; the upper end of the hydraulic oil pipe 8 is connected to the lower part of the upper joint 1, and the lower end is connected to the hydraulic oil pipe joint under the hydraulic cylinder body 11.

[0048] like Figure 3 As shown, the upper joint 1 is internally provided with a throttle chamber for connecting the hydraulic oil pipe 8 to the main hydraulic oil circuit. The throttle chamber inside the upper joint 1 allows the hydraulic oil pipe 8 and the main hydraulic oil circuit to be connected on different axes, facilitating the movement of the hydraulic oil pipe 8 to the side of the interior of the flexible tapered casing expansion tool, leaving the internal axis position of the flexible tapered casing expansion tool for installing the hydraulic cylinder piston shaft 10. The return spring compartment housing 3 is provided with a limit baffle, with a through hole with a diameter of 120 mm opened in the center of the limit baffle, and a 50 mm through hole opened on the upper side of the limit baffle for passing the hydraulic oil pipe 8.

[0049] like Figure 3 and Figure 4 As shown, the stopper allows the hydraulic cylinder piston shaft 10 to pass through and move freely axially within a range of 350mm. The return spring 9 passing through the hydraulic cylinder piston shaft 10 contacts the stopper and cannot pass through the stopper. The central portion of the hydraulic cylinder piston shaft 10 is the piston portion, which is installed in the hydraulic cylinder body 11. The piston portion is provided with two slots for installing the sealing ring 12. The upper portion of the hydraulic cylinder piston shaft 10 is provided with a shaft shoulder to limit the return spring 9. The lower portion of the hydraulic cylinder piston shaft 10 is installed with a spherical plug 7.

[0050] like Figure 3 As shown, 10 flexible cone springs 6 are installed under the hydraulic chamber housing 5. The flexible cone springs 6 will elastically deform when subjected to external forces. The elastic deformation of the flexible cone springs 6 under the force forms an arch, thereby generating an expansion effect.

[0051] like Figure 3 and Figure 4As shown, when the hydraulic cylinder piston shaft 10 is subjected to hydraulic pressure, it will move axially. At this time, the return spring 9 begins to compress under the action of the shaft shoulder on the upper part of the hydraulic cylinder piston shaft 10 and the limit baffle in the return spring chamber housing 3. When the hydraulic pressure decreases, the return spring 9 rebounds to ensure that the hydraulic cylinder piston shaft 10 returns to its initial position.

[0052] like Figure 4 and Figure 6 As shown, the lower part of the flexible cone spring piece 6 is fixed to the hydraulic cylinder piston shaft 10 through the spherical plug 7 installed at the lower part of the hydraulic cylinder piston shaft 10; when the hydraulic cylinder piston shaft 10 is subjected to hydraulic pressure and axial movement, the flexible cone spring piece 6 undergoes elastic deformation to form an arch; when the 10 flexible cone spring pieces 6 undergo elastic deformation at the same time to form an arch, an expansion effect is exerted on the casing.

[0053] like Figure 3 As shown, two outwardly protruding bosses are provided on the side of the hydraulic cylinder body 11 , and two inner grooves are also provided in the hydraulic chamber housing 5 to match the two outwardly protruding bosses on the side of the hydraulic cylinder body 11 .

[0054] Working principle of the patented invention:

[0055] The flexible cone casing expansion tool is placed into the casing and moved to the location where the casing expansion is required. When the flexible cone casing expansion tool reaches the predetermined position, hydraulic oil is pressed into the hydraulic cylinder body 11. Under the action of the hydraulic oil pressure, the hydraulic cylinder piston shaft 10 causes the flexible cone spring 6 to elastically deform, forming an arch, expanding the corresponding part of the casing and simultaneously causing the casing to plastically deform. When the flexible cone casing expansion tool has completed expansion, the hydraulic oil pressure is released, and the hydraulic cylinder piston shaft 10 returns to its initial position under the combined action of the return spring 9 and the flexible cone spring 6. The flexible cone casing expansion tool returns to its initial state, leaving a groove on the casing. Repeating these steps can expand the casing to the desired number of grooves.

Claims

1. A flexible cone casing expansion method, characterized in that: The flexible cone casing expansion method is used for side drilling a new well in an old well. The flexible cone casing expansion method is based on a flexible cone casing expansion tool. The flexible cone casing expansion tool comprises an upper joint (1), a connecting outer shell (2) connected below the upper joint (1), a return spring chamber shell (3) connected below the connecting outer shell (2), a return spring chamber cover (4) on the return spring chamber shell (3), a return spring (9) installed in the return spring chamber shell (3), a hydraulic cylinder piston shaft (10) passing through the return spring (9), and a hydraulic chamber shell (5) connected below the return spring chamber shell (3). , a hydraulic cylinder body (11) installed in the hydraulic chamber housing (5), a flexible cone shrapnel (6) installed under the hydraulic chamber housing (5), and a spherical plug (7) below the hydraulic cylinder piston shaft (10); a passage is provided in the upper joint (1), the connecting outer shell (2), the return spring chamber housing (3), and the hydraulic chamber housing (5) for passing the hydraulic oil pipe (8); a hydraulic oil pipe joint is provided below the hydraulic cylinder body (11); the upper end of the hydraulic oil pipe (8) is connected to the lower part of the upper joint (1), and the lower end is connected to the hydraulic oil pipe joint below the hydraulic cylinder body (11); Ten flexible cone shrapnels (6) are installed under the hydraulic chamber housing (5), and the flexible cone shrapnels (6) are elastically deformed when subjected to external forces; The lower portion of the flexible cone shrapnel (6) is fixed to the hydraulic cylinder piston shaft (10) via a spherical plug (7) installed at the lower portion of the hydraulic cylinder piston shaft (10); when the hydraulic cylinder piston shaft (10) is subjected to hydraulic pressure and undergoes axial movement, the flexible cone shrapnel (6) undergoes elastic deformation to form an arch; when the ten flexible cone shrapnel (6) undergo elastic deformation simultaneously to form an arch, an expansion effect is exerted on the casing; The flexible cone casing expansion method comprises: S1. Place the flexible cone casing expansion tool into the casing and move it to the location where the casing needs to be expanded; S2. When the flexible cone casing expansion tool reaches a predetermined position, hydraulic oil is pressed into the hydraulic cylinder body (11). Under the action of the hydraulic oil pressure, the hydraulic cylinder piston shaft (10) drives the flexible cone spring (6) to undergo elastic deformation, forming an arch, thereby expanding the corresponding part of the casing, and at the same time, the casing undergoes plastic deformation; S3. After the expansion of the flexible cone casing expansion tool is completed, the pressure of the hydraulic oil is released, and the hydraulic cylinder piston shaft (10) returns to the initial position under the combined action of the return spring (9) and the flexible cone shrapnel (6). The flexible cone casing expansion tool returns to its initial state, leaving a groove on the casing. Repeating the above steps can expand the required number of grooves. S4. Pause the hydraulic pump and pull out the flexible cone casing expansion tool.

2. A flexible cone casing expansion method according to claim 1, characterized in that: A throttling chamber is provided inside the upper joint (1) for connecting the hydraulic oil pipe (8) and the main hydraulic oil circuit.

3. A flexible cone casing expansion method according to claim 1, characterized in that: The return spring chamber housing (3) is provided with a limit baffle, a through hole with a diameter of 120 mm is opened in the center of the limit baffle, and a through hole with a diameter of 50 mm is opened on the side of the limit baffle for passing the hydraulic oil pipe (8).

4. A flexible cone casing expansion method according to claim 3, characterized in that: The limit baffle allows the hydraulic cylinder piston shaft (10) to pass through and can freely move axially with a range of motion of 350 mm; the return spring (9) passing through the hydraulic cylinder piston shaft (10) contacts the limit baffle, and the return spring (9) cannot pass through the limit baffle.

5. A flexible cone casing expansion method according to claim 4, characterized in that: The middle portion of the hydraulic cylinder piston shaft (10) is a piston portion, which is installed in the hydraulic cylinder body (11). Two slots are provided in the piston portion for installing a sealing ring (12); a shaft shoulder is provided on the upper portion of the hydraulic cylinder piston shaft (10) for limiting the return spring (9); and a spherical plug (7) is installed on the lower portion of the hydraulic cylinder piston shaft (10).

6. A flexible cone casing expansion method according to claim 5, characterized in that: When the hydraulic cylinder piston shaft (10) is subjected to hydraulic pressure, it will move axially. At this time, the return spring (9) begins to compress under the action of the shaft shoulder on the upper part of the hydraulic cylinder piston shaft (10) and the limit baffle in the return spring chamber housing (3). When the hydraulic pressure decreases, the return spring (9) rebounds to ensure that the hydraulic cylinder piston shaft (10) returns to its initial position.

7. The flexible cone casing expansion method according to claim 1, characterized in that: Two outwardly protruding bosses are provided on the side of the hydraulic cylinder body (11), and two inner grooves matching the two outwardly protruding bosses on the side of the hydraulic cylinder body (11) are also provided in the hydraulic chamber housing (5).

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