Combined sealing and anchoring device for sidetracking well

Abstract

The invention belongs to the field of downhole tools for oil and gas fields, and discloses a sidetracking well combined sealing and anchoring device. Comprising an upper connector, a shear pin, a connecting sleeve, a shear ring, a trial insertion shear pin, a sealing sleeve, a sealing sleeve back cap, a clamping ring, a sealing ring back cap, an upper metal ring, an upper gasket, a sealing ring, a central pipe, a lower gasket, a lower metal ring, a back cap, a releasing shear pin, a supporting sleeve, an elastic sleeve and a barb-shaped chamfer. The device can be prevented from being ejected out of an inner cavity of an underground tool when being stressed during fracturing construction, and after the fracturing construction is completed, the pipe column can be lifted up to shear off the releasing shear pin, so that the pipe column is pulled out.

Description

Technical Field

[0001] The invention belongs to the field of downhole tools for oil and gas fields, and in particular relates to a side drilling combined sealing and anchoring device. Background Art

[0002] Sidetracking is a process in which, based on the original wellbore trajectory (vertical well, directional well, horizontal well), special sidetracking tools are used to make the drilling trajectory of the drill bit deviate from the original wellbore trajectory as pre-designed for special process needs.

[0003] Side drilling and side drilling horizontal wells are old oil field development technologies with low investment, quick results and significant economic benefits. As early as the 1920s, foreign countries proposed to use side drilling to increase oil well production. However, due to the limitations of drilling and completion technology, the technology did not make a qualitative leap until the 1980s. In the 1990s, the side drilling technology was perfected and the number of side drilling wells increased rapidly. my country's side drilling technology began in the 1950s, but it did not develop significantly until the 1990s.

[0004] At present, China's oil system generally uses oil pipes and small-diameter packers to seal + hydraulic anchors to connect back to the side-drilling section for completion. However, due to the limitations of the hydraulic anchor tool structure and the large size of the sealing device, it is difficult to achieve large-scale segmented transformation of the large-diameter full-well casing in side-drilling wells. Summary of the invention

[0005] In order to overcome the shortcomings of the prior art, the present invention provides a side drilling combined sealing and anchoring device to meet the side drilling sealing and anchoring requirements and realize the side drilling large diameter full well casing completion and later segmented transformation requirements.

[0006] The above-mentioned purpose of the present invention is achieved through the following technical scheme: a side drilling combined sealing and anchoring device, including an upper joint, a shear nail, a connecting sleeve, a shear ring, a trial shear nail, a sealing sleeve, a sealing sleeve back cap, a clamping ring, a sealing ring back cap, an upper metal ring, an upper gasket, a sealing ring, a central pipe, a lower gasket, a lower metal ring, a back cap, a hand-release shear nail, a support sleeve, an elastic sleeve, and a hook-shaped chamfer.

[0007] The outer side of the lower end of the upper joint is connected to the inner side of the upper end of the connecting sleeve with a left-hand thread and fixed by shear nails to prevent rotation; the lower end of the connecting sleeve is connected to the upper end of the center pipe with a thread;

[0008] The shear ring is installed on the outside of the center tube, the shoulder is limited and fixed by the trial shear nails;

[0009] The sealing sleeve and the sealing sleeve back cap are installed on the outside of the central tube; the clamping ring is installed in the ring groove on the outside of the central tube, and the outer side of the lower end of the sealing sleeve back cap is threadedly connected with the inner side of the upper end of the sealing ring back cap;

[0010] The upper metal ring, the upper gasket, the sealing ring, the lower gasket and the lower metal ring are installed on the outer side of the central tube, and are limited by the sealing ring back cap and the back cap, and the inner side of the back cap is threadedly connected with the outer side of the central tube;

[0011] The lower end of the center tube is connected to the upper end of the support sleeve by a shear nail, and an elastic sleeve is installed on the outside of the support sleeve; the elastic sleeve is provided with a barb-shaped chamfer and a plurality of evenly distributed vertical grooves;

[0012] The working process of a side drilling combined sealing and anchoring device of the present invention is as follows:

[0013] The device is docked with the downhole tool, and the upper joint is connected to the oil tubing string. When the oil tubing string is slowly lowered to the downhole tool position, the shear ring contacts the downhole tool. The hanging weight of the oil tubing string is reduced, indicating that the device has been lowered to the designed position. After the length of the oil tubing string is configured, the oil tubing string is continued to be lowered, the trial shear nails are cut off, the shear ring moves upward, the device enters the inner cavity of the downhole tool, and the combined seal enters the inner cavity of the downhole tool to form a seal with it; the elastic sleeve body is deformed and the outer diameter is reduced. After being introduced into the inner cavity of the downhole tool, it returns to its original shape, and the barb-shaped chamfer on the elastic sleeve enters the corresponding inner cavity of the downhole tool.

[0014] During fracturing construction, when the device moves upward under the pressure difference, the barb-shaped chamfer on the elastic sleeve docks with the corresponding shoulder in the inner cavity of the downhole tool, and the outer slope shoulder of the support sleeve fits with the corresponding slope shoulder on the inner side of the elastic sleeve to form a support. At this time, the elastic sleeve body cannot deform toward the inner cavity, and the barb-shaped chamfer on the elastic sleeve docks with the shoulder in the inner cavity of the downhole tool to anchor the device, preventing the device from being pushed out of the inner cavity of the downhole tool.

[0015] After the fracturing construction is completed, the oil pipe string is lifted up, the shear nails are cut off, and the oil pipe string is continued to be lifted up to lift the device out of the well. If the device encounters resistance when lifting the oil pipe string, the oil pipe string can be rotated forward to make the device inverted and released from the left-handed thread of the upper joint and the connecting sleeve. The downhole part can be lifted out of the well together with the downhole tools later.

[0016] Compared with the prior art, the invention has the following beneficial effects: the anchoring mechanism composed of the hand-drop shear nail, the support sleeve and the elastic sleeve can be anchored on the corresponding shoulder after entering the inner cavity of the downhole tool, thereby preventing the device from being pushed out of the inner cavity of the downhole tool when subjected to force during fracturing construction;

[0017] The support sleeve and the center pipe are connected by shear pins. After the fracturing construction is completed, the pipe string can be lifted up to cut off the shear pins and pull out the pipe string.

[0018] A shear ring is provided on the center tube, and the shear ring and the center tube are connected by trial shear pins. The trial shear pins are installed on the outer surface of the shear ring and the number of the trial shear pins is adjustable. When the device is docked with the downhole tool, the shear ring and the trial shear pins are subjected to force, and the load on the ground hanging weight meter is displayed to be reduced, which indicates that the device is in place. This can prevent the device from directly entering the inner cavity of the downhole tool, causing the anchoring mechanism to be anchored and the wellhead to be unable to be installed. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

[0020] Figure 1 It is a schematic diagram of the structure of the present invention.

[0021] Figure 2 It is a partial schematic diagram of the chamfer of the barb shape on the elastic sleeve of the present invention.

[0022] Figure 3 It is a three-dimensional axonometric drawing of the elastic sleeve of the present invention.

[0023] In the figure, 1. upper joint; 2. shear pin; 3. connecting sleeve; 4. shear ring; 5. trial shear pin; 6. sealing sleeve; 7. sealing sleeve back cap; 8. retaining ring; 9. sealing ring back cap; 10. upper metal ring; 11. upper gasket; 12. sealing ring; 13. center tube; 14. lower gasket; 15. lower metal ring; 16. back cap; 17. shear pin; 18. supporting sleeve; 19. elastic sleeve; 20. hook-shaped chamfer. DETAILED DESCRIPTION

[0024] The present invention is described in detail below by specific examples, but the protection scope of the present invention is not limited. Unless otherwise specified, the experimental methods used in the present invention are all conventional methods, and the experimental equipment, materials, reagents, etc. used can be obtained from commercial channels.

[0025] Example 1

[0026] A side drilling combined sealing and anchoring device, comprising: an outer side of a lower end of an upper joint 1 is connected to an inner side of an upper end of a connecting sleeve 3 by a left-handed thread and fixed to prevent rotation by a shear nail 2; a lower end of the connecting sleeve 3 is connected to an upper end of a central pipe 13 by a thread;

[0027] The shear ring 4 is installed on the outside of the central tube 13, the shoulder is limited and fixed by the trial-inserted shear nails 5;

[0028] The sealing sleeve 6 and the sealing sleeve back cap 7 are installed on the outside of the central tube 12; the clamping ring 8 is installed in the ring groove on the outside of the central tube 13, and the outer side of the lower end of the sealing sleeve back cap 7 is threadedly connected with the inner side of the upper end of the sealing ring back cap 9;

[0029] The upper metal ring 10, the upper gasket 11, the sealing ring 12, the lower gasket 14 and the lower metal ring 15 are installed on the outer side of the central tube 13 and are limited by the sealing ring back cap 9 and the back cap 16. The inner side of the back cap 16 is threadedly connected with the outer side of the central tube 13.

[0030] The lower end of the central tube 13 is connected to the upper end of the support sleeve 18 by a shear nail 17. An elastic sleeve 19 is installed outside the support sleeve 18. The elastic sleeve 19 is provided with a barb-shaped chamfer 20 and a plurality of evenly distributed vertical grooves.

[0031] The working process of the side drilling combined sealing and anchoring device is as follows:

[0032] The device is docked with the downhole tool, and the upper joint 1 is connected to the oil pipe string. The oil pipe string is not shown in the figure. When the downhole reaches the position of the downhole tool, the oil pipe string is slowly lowered. When the shear ring 4 contacts the downhole tool, the hanging weight of the oil pipe string is reduced, indicating that the device has been lowered to the designed position. After the length of the oil pipe string is configured, it continues to be lowered into the oil pipe string, the trial shear nail 5 is cut off, the shear ring 4 goes up, the device enters the inner cavity of the downhole tool, and the combined seal enters the inner cavity of the downhole tool to form a seal with it; the elastic sleeve 19 body is deformed and the outer diameter is reduced. After being introduced into the inner cavity of the downhole tool, it returns to its original state, and the barb-shaped chamfer 20 on the elastic sleeve 19 enters the corresponding inner cavity of the downhole tool. -

[0033] During fracturing construction, when the device is subjected to the upper pressure difference and moves upward, the barb-shaped chamfer 20 on the elastic sleeve 19 docks with the corresponding shoulder in the inner cavity of the downhole tool, and the outer slope shoulder of the support sleeve 18 fits with the corresponding slope shoulder on the inner side of the elastic sleeve 19 to form a support. At this time, the elastic sleeve 19 body cannot deform toward the inner cavity, and the barb-shaped chamfer 20 on the elastic sleeve 19 docks with the shoulder in the inner cavity of the downhole tool to anchor the device, preventing the device from being pushed out of the inner cavity of the downhole tool.

[0034] After the fracturing construction is completed, the oil pipe string is lifted up, the shear nail 17 is cut off, and the oil pipe string is continued to be lifted up to pull the device out of the well. If the device encounters resistance when lifting the oil pipe string, the oil pipe string can be rotated forward to make the device inverted and released from the left-handed thread of the upper joint 1 and the connecting sleeve 3. The downhole part can be pulled out of the well together with the downhole tool at a later stage.

[0035] Example 2

[0036] The device is docked with the downhole tool, and the upper joint 1 is connected to the oil tubing string. The oil tubing string is not shown in the figure. When the downhole reaches the downhole tool position, the oil tubing string is slowly lowered. When the shear ring 4 contacts the downhole tool, the hanging weight of the oil tubing string is reduced, indicating that the device has been lowered to the designed position. After the length of the oil tubing string is configured, the oil tubing string is continued to be lowered, the trial shear nail 5 is cut off, the shear ring 4 goes up, the device enters the inner cavity of the downhole tool, and the combined seal enters the inner cavity of the downhole tool to form a seal with it; the elastic sleeve 19 body is deformed and the outer diameter is reduced. After being introduced into the inner cavity of the downhole tool, it returns to its original state, and the barb-shaped chamfer 20 on the elastic sleeve 19 enters the corresponding inner cavity of the downhole tool.

[0037] During fracturing construction, when the device is subjected to the upper pressure difference and moves upward, the barb-shaped chamfer 20 on the elastic sleeve 19 docks with the corresponding shoulder in the inner cavity of the downhole tool, and the outer slope shoulder of the support sleeve 18 fits with the corresponding slope shoulder on the inner side of the elastic sleeve 19 to form a support. At this time, the elastic sleeve 19 body cannot deform toward the inner cavity, and the barb-shaped chamfer 20 on the elastic sleeve 19 docks with the shoulder in the inner cavity of the downhole tool to anchor the device, preventing the device from being pushed out of the inner cavity of the downhole tool.

[0038] After the fracturing construction is completed, the oil pipe string is lifted up, the shear nail 17 is cut off, and the oil pipe string is continued to be lifted up to pull the device out of the well. If the device encounters resistance when lifting the oil pipe string, the oil pipe string can be rotated forward to make the device inverted and released from the left-handed thread of the upper joint 1 and the connecting sleeve 3. The downhole part can be pulled out of the well together with the downhole tool at a later stage.

[0039] The above-described embodiments are only preferred embodiments of the present invention, but not all feasible embodiments of the present invention. For those skilled in the art, any obvious changes made thereto without departing from the principles and spirit of the present invention should be considered to be included in the scope of protection of the claims of the present invention.

Claims

1. A side drilling well combined sealing and anchoring device, characterized in that: The invention comprises an upper joint (1), a shear pin (2), a connecting sleeve (3), a shear ring (4), a trial insertion shear pin (5), a sealing sleeve (6), a sealing sleeve back cap (7), a clamping ring (8), a sealing ring back cap (9), an upper metal ring (10), an upper gasket (11), a sealing ring (12), a central tube (13), a lower gasket (14), a lower metal ring (15), a back cap (16), a hand-release shear pin (17), a supporting sleeve (18), an elastic sleeve (19), and a hook-shaped chamfer (20).

2. The side drilling combined sealing and anchoring device according to claim 1, characterized in that: The outer side of the lower end of the upper joint (1) is connected to the inner side of the upper end of the connecting sleeve (3) by a left-handed thread and is fixed by a shear nail (2) to prevent rotation; the lower end of the connecting sleeve (3) is connected to the upper end of the center pipe (13) by a thread.

3. The side drilling combined sealing and anchoring device according to claim 1, characterized in that: The shear ring (4) is installed on the outside of the center tube (13), and the shoulder is limited and fixed by the trial-inserted shear nail (5).

4. The side drilling combined sealing and anchoring device according to claim 1, characterized in that: The sealing sleeve (6) and the sealing sleeve back cap (7) are installed on the outside of the central tube (12); the clamping ring (8) is installed in the ring groove on the outside of the central tube (13); the outer side of the lower end of the sealing sleeve back cap (7) is threadedly connected with the inner side of the upper end of the sealing ring back cap (9).

5. The side drilling combined sealing and anchoring device according to claim 1, characterized in that: An upper metal ring (10), an upper gasket (11), a sealing ring (12), a lower gasket (14) and a lower metal ring (15) are installed on the outside of a central tube (13) and are limited by a sealing ring back cap (9) and a back cap (16). The inner side of the back cap (16) is threadedly connected to the outer side of the central tube (13).

6. The side drilling combined sealing and anchoring device according to claim 1, characterized in that: The lower end of the central tube (13) is connected to the upper end of the support sleeve (18) by a shear nail (17). An elastic sleeve (19) is arranged outside the support sleeve (18); the elastic sleeve (19) is provided with a barb-shaped chamfer (20) and a plurality of evenly distributed vertical grooves.

7. The working process of the side drilling combined sealing and anchoring device according to claim 1 is characterized in that: The steps are as follows: the device is docked with the downhole tool, the upper joint (1) is connected to the oil pipe string and the oil pipe string is slowly lowered when it reaches the downhole tool position, the shear ring (4) contacts the downhole tool and the hanging weight of the oil pipe string is reduced, indicating that the device has been lowered to the designed position, and after the length of the oil pipe string is configured, the oil pipe string is continued to be lowered, the trial shear nail (5) is cut off, the shear ring (4) moves upward, the device enters the inner cavity of the downhole tool, and the combined seal enters the inner cavity of the downhole tool to form a seal with it; the elastic sleeve (19) body is deformed and the outer diameter is reduced, and it returns to its original state after being introduced into the inner cavity of the downhole tool, and the barb-shaped chamfer (20) on the elastic sleeve (19) enters the corresponding inner cavity of the downhole tool; during fracturing construction, when the device is subjected to the upper pressure difference and moves upward, the barb on the elastic sleeve (19) The chamfer (20) is butted against the corresponding shoulder of the inner cavity of the downhole tool, and the outer slope shoulder of the support sleeve (18) is fitted against the corresponding slope shoulder of the inner side of the elastic sleeve (19) to form a support. At this time, the elastic sleeve (19) body cannot deform toward the inner cavity, and the barb-shaped chamfer (20) on the elastic sleeve (19) is butted against the shoulder of the inner cavity of the downhole tool to anchor the device, thereby preventing the device from being pushed out of the inner cavity of the downhole tool. After the fracturing operation is completed, the oil pipe string is lifted up, the shear nail (17) is cut off, and the oil pipe string is continued to be lifted up to lift the device out of the well. If the device encounters resistance when lifting the oil pipe string, the oil pipe string can be rotated forward to make the device buckled and released from the left-handed thread of the upper joint (1) and the connecting sleeve (3), and the downhole part can be lifted out of the well together with the downhole tool at a later stage.

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