Multi-channel packing sliding sleeve

Abstract

Multi-channel filling sliding sleeve, the upper outer wall of the body is connected with the upper end of the bypass sleeve; the middle part of the side wall of the body and the bypass sleeve is respectively provided with a plurality of through inner and outer filling holes, which are communicated to form a first channel; the annular opening is formed between the lower outer wall of the body and the lower end of the bypass sleeve, forming a second channel; the lower outer wall of the body is connected with the piston through a shear pin, and the piston is sealed with the outer wall of the boss and the inner wall of the bypass sleeve; when the first channel is blocked, the pressure rises until the shear pin is sheared, the piston goes down, and the second channel is opened. The utility model discloses a second channel and a separable piston are arranged between the body and the bypass sleeve, after sand plugging occurs in conventional filling, the piston is separated and the second channel is automatically opened by pressure, so that the sand-carrying liquid can pass through the sand bridge or the blockage, and the filling efficiency and success rate are improved.

Description

Technical Field

[0001] This utility model relates to a gravel packing completion tool for open-hole horizontal wells in oil and gas, specifically a multi-channel packing sliding sleeve. Background Technology

[0002] With the development of offshore oil fields and the limited availability of well slots, horizontal wells are increasingly being used to increase drainage area, improve production, and reduce operating costs. However, the development of long or deepwater horizontal wells at sea is challenging and costly, requiring a high success rate for first-time well completion.

[0003] To improve the service life of screen pipe sand control, gravel packing is an important sand control method. The gravel packing layer can support the wellbore between the screen pipe and the wellbore and prevent formation sand from entering the oil well. In offshore long horizontal wells or deepwater horizontal wells with open hole gravel packing, there are risks such as early sand bridging, low formation fracture pressure, serious leakage during circulation testing, and irregular wellbore. Sand bridges and blockages are easily formed, resulting in some well sections with incomplete packing or no packing at all.

[0004] Especially during gravel packing operations in horizontal wells, packing gaps can occur due to formation or design issues. Field experience shows that 30% of horizontal open-hole wells fail to complete gravel packing due to mudstone collapse; long horizontal gravel packing sections may fail to reach the wellhead for various reasons, leading to premature sand blockage. For unpacked sections, packing cannot continue, significantly impacting construction efficiency. Summary of the Invention

[0005] To address the aforementioned problems, this invention aims to provide a multi-channel filling sleeve that can continue filling even after sand blockage occurs during conventional filling, thereby improving filling efficiency.

[0006] To achieve the above objectives, the technical solution adopted by this utility model includes a main body, an outer bypass sleeve fitted around the main body, and the upper outer wall of the main body connected to the upper end of the bypass sleeve; the middle sidewalls of the main body and the bypass sleeve are respectively provided with a plurality of through inner and outer filling holes, which are connected to form a first channel.

[0007] The lower outer wall of the main body and the lower end of the bypass sleeve form an annular opening, forming a second channel; the lower outer wall of the main body is also provided with a boss, and the outer wall of the boss is detachably connected to the piston through a shear pin, and the piston forms a seal with the outer wall of the boss and the inner wall of the bypass sleeve respectively.

[0008] When the first channel is blocked, the pressure rises until the shear pin is broken, the piston moves downward, and then the second channel is opened.

[0009] Furthermore, the upper outer wall of the main body is connected to the upper inner wall of the bypass sleeve by threads, and is provided with an anti-rotation pin.

[0010] Furthermore, after the piston descends, it is stopped by the upper end of the lower tool joint located below.

[0011] Furthermore, the inner and outer walls of the piston are sealed to the outer wall of the boss and the inner wall of the bypass sleeve by O-rings, respectively.

[0012] Furthermore, there are six inner filling holes and six outer filling holes.

[0013] Furthermore, the total area of ​​the plurality of external filling holes must be no less than the total area of ​​the plurality of internal filling holes; and / or, the area of ​​the second channel must be no less than the total area of ​​the plurality of internal filling holes.

[0014] Furthermore, the body has an axially movable switch sleeve inside. When the side wall of the switch sleeve blocks the inner filling hole, the first channel is closed.

[0015] Furthermore, the outer walls of the upper and lower ends of the switch sleeve form a seal with the inner wall of the body to seal the upper and lower ends of the inner filling hole.

[0016] Furthermore, the upper section of the main body is provided with an upper connector, the lower end of which is connected to a limiting sleeve. The lower end of the limiting sleeve is used to limit the upward travel of the switch sleeve.

[0017] Compared with existing technologies, this utility model sets a second channel and a separable piston between the main body and the bypass sleeve. After sand blockage occurs during conventional filling, the pressure in the first channel pushes the piston to separate and automatically open the second channel, allowing the sand-carrying fluid to pass through the sand bridge or blockage. This allows it to cooperate with the bypass screen pipe to continue filling, improving filling efficiency and success rate, ensuring the normal progress of sand control construction in horizontal wells, improving the reliability of the bypass screen pipe, and better guaranteeing the sand control effect and long-term development of offshore oil fields. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the initial state of an embodiment of the present invention;

[0019] Figure 2 This is a schematic diagram of the second channel in the open state according to an embodiment of the present invention;

[0020] Referring to the attached diagram, the components are: upper connector 1, limiting sleeve 2, main body 3, bypass sleeve 4, inner filling hole 5, switch sleeve 6, outer filling hole 7, sealing cylinder 8, piston 9, shearing pin 10, and lower tool connector 11. Detailed Implementation

[0021] The present invention will now be further described with reference to the accompanying drawings. For ease of description, the following will refer to... Figure 1 The direction of the middle and upper connector is "up" and the opposite is "down".

[0022] See Figure 1 , Figure 1 This illustration shows one embodiment of the present invention. This embodiment mainly includes a body, which comprises an upper connector, a main body, and a sealing cylinder connected sequentially from top to bottom. A bypass sleeve is also fitted over the main body. The upper outer wall of the main body is threadedly connected to the upper inner wall of the bypass sleeve and is secured with an anti-rotation pin.

[0023] The main body and the bypass sleeve are provided with several through inner and outer filling holes in the middle side wall; the internal space of the main body passes through the inner filling hole, through the annular space between the outer wall of the main body and the inner wall of the bypass sleeve, and finally connects with the outer filling hole to form the first channel.

[0024] An annular opening (i.e., the lower end face of the aforementioned annular space) is formed between the outer wall of the sealing cylinder and the lower inner wall of the bypass sleeve, which serves as the second channel. A radially outward protruding boss is also provided on the outer wall of the sealing cylinder near the lower annular opening within the annular space. A piston for blocking is provided between the outer wall of the boss and the inner wall of the bypass sleeve, and the boss is separably connected to the piston via a shear pin. When the pressure within the annular space exceeds a preset threshold, the shear pin is sheared, causing the piston to separate from the boss and descend. After the piston has descended a sufficiently long distance to completely disengage from the boss, the second channel is opened after the piston descends because its size is smaller than the annular opening. Preferably, the descending piston is restricted in its movement by the upper end of the lower tool connector of the sliding sleeve, and the upper outer wall of the lower tool connector is connected to the lower inner wall of the bypass pipe.

[0025] Furthermore, the inner and outer walls of the piston are sealed to the outer wall of the boss and the inner wall of the bypass sleeve by O-rings, respectively, so that the second channel below remains sealed until it is opened.

[0026] Preferably, in this embodiment, the main body is provided with six internal filling holes, and the bypass sleeve is also provided with six external filling holes; the number of holes can be flexibly selected and is not a limitation of this utility model. Furthermore, the total area of ​​the external filling holes should not be less than the total area of ​​the internal filling holes, and the area of ​​the second channel should not be less than the total area of ​​a plurality of internal filling holes.

[0027] In this embodiment, the device is vertically lowered into the well with the switch sleeve closed and the second channel inactive. If there is no blockage at the sand inlet of the bypass screen, the first channel can be filled normally, and the pressure inside the channel is stable, failing to reach the activation pressure of the second channel. Therefore, the second channel will not affect the filling operation of the first channel. However, during sand control filling, if blockage occurs due to early sand bridging, formation collapse, local wellbore irregularities, or clay expansion in mudstone sections, the external channel of the screen will be blocked. In this case, the sand-carrying fluid cannot enter the sand-carrying fluid transmission pipe inside the bypass screen, significantly reducing the filling efficiency of the bypass screen. Simultaneously, the first channel cannot be filled normally due to blockage, causing the pressure inside the first channel to rise. When the pressure rises to the activation pressure / threshold set for the second channel, the shear pin is sheared by the piston. At this point, the piston separates from the boss and is pushed downwards by the pressure, opening the second channel. At this point, the second channel in this embodiment is connected to the transmission pipe of the bypass screen pipe. The sand-carrying fluid can directly enter the transmission pipe of the bypass screen pipe through the second channel, which solves the problem that the sand-carrying fluid cannot enter the transmission pipe due to blockage caused by formation collapse or other reasons at the sand inlet of the bypass screen pipe. Furthermore, the piston can automatically activate the second channel under pressure without the need for manual intervention at the wellhead, and the use of the first channel is not affected after the piston is opened.

[0028] See Figure 1 and Figure 2 The main body contains an axially movable switch sleeve; the switch sleeve, together with the upper connector, limiting sleeve, sealing cylinder, and various soft sealing components, forms a switch valve mechanism. In this embodiment, the up-and-down movement of the switch sleeve driven by an existing switching tool can close or open the first channel; the inner wall of the switch sleeve is adapted to the shape of the outer wall of the switching tool. Specifically, see... Figure 1 When the switch sleeve moves upward, its side wall blocks the inner filling hole, and the first channel is in a closed state. (See also...) Figure 2 When the switch sleeve moves downward, its side wall completely disengages from the inner filling hole, and the first channel is in the open state.

[0029] Preferably, the outer walls of the upper and lower ends of the switch sleeve are sealed to the inner wall of the body by O-rings. When the switch is closed, the two O-rings are located above and below the inner filling hole, respectively, which further seals both ends of the switch sleeve.

[0030] Preferably, the lower end of the upper connector is connected to a limiting sleeve, which is located inside the main body. The lower end of the limiting sleeve can be used to limit the upward travel of the switch sleeve to prevent device malfunction. Furthermore, the upper and lower ends of the switch sleeve can be provided with toothed structures, which can convert the axial force applied by the switching tool into a radial force to realize the locking function of the switch sleeve. When the axial force of the switch sleeve reaches a set value, the sliding sleeve is opened or closed.

[0031] The embodiments of this utility model have been described above with reference to the accompanying drawings and examples. The structures given in the embodiments do not constitute a limitation on this utility model. Those skilled in the art can make adjustments as needed, and various modifications or variations within the scope of the appended claims are all within the scope of protection.

Claims

1. A multi-channel filling sliding sleeve, comprising a body, characterized in that: The body is fitted with a bypass sleeve, and the upper outer wall of the body is connected to the upper end of the bypass sleeve; the middle side walls of the body and the bypass sleeve are respectively provided with several through inner and outer filling holes, which are connected to form a first channel. The lower outer wall of the main body and the lower end of the bypass sleeve form an annular opening, forming a second channel; the lower outer wall of the main body is also provided with a boss, and the outer wall of the boss is detachably connected to the piston through a shear pin, and the piston forms a seal with the outer wall of the boss and the inner wall of the bypass sleeve respectively. When the first channel is blocked, the pressure rises until the shear pin is broken, the piston moves downward, and then the second channel is opened.

2. The multi-channel filling sliding sleeve according to claim 1, characterized in that: The upper outer wall of the main body is connected to the upper inner wall of the bypass sleeve by threads, and is equipped with an anti-rotation pin.

3. The multi-channel filling sliding sleeve according to claim 1, characterized in that: After the piston descends, it is stopped by the upper end of the lower tool joint located below.

4. The multi-channel filling sliding sleeve according to claim 1, characterized in that: The inner and outer walls of the piston are sealed to the outer wall of the boss and the inner wall of the bypass sleeve by O-rings, respectively.

5. The multi-channel filling sliding sleeve according to claim 1, characterized in that: The number of inner filling holes is six; and / or, the number of outer filling holes is six.

6. The multi-channel filling sliding sleeve according to any one of claims 1-4, characterized in that: The total area of ​​the external filling holes must be no less than the total area of ​​the internal filling holes; and / or, the area of ​​the second channel must be no less than the total area of ​​the internal filling holes.

7. The multi-channel filling sliding sleeve according to claim 1, characterized in that: The main body has an axially movable switch sleeve inside. When the side wall of the switch sleeve blocks the inner filling hole, the first channel is closed.

8. The multi-channel filling sliding sleeve according to claim 6, characterized in that: The outer walls of the upper and lower ends of the switch sleeve form a seal with the inner wall of the body.

9. The multi-channel filling sliding sleeve according to claim 6, characterized in that: The upper section of the main body is provided with an upper connector, and the lower end of the upper connector is connected to a limiting sleeve. The lower end of the limiting sleeve is used to limit the upward travel of the switch sleeve.

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