A composite sand control downhole slip-type choke

Abstract

The utility model relates to a kind of composite sand control type downhole slip type flow restrictor, including composite sand control structure;Composite sand control structure includes the pipe base being located at the bottom end of slip type flow restrictor, sand control outer tube being installed in the bottom side of pipe base, sand control inner tube being installed in the bottom side of pipe base and being located in the inboard of sand control outer tube;The bottom end of sand control outer tube, the bottom end of sand control inner tube are blind end;The sidewall of sand control outer tube is equipped with multiple first sand control gap slots equidistantly distributed along length direction;The sidewall of sand control inner tube is equipped with multiple second sand control gap slots equidistantly distributed along length direction;The region of multiple first sand control gap slots and the region of multiple second sand control gap slots correspond.The utility model relates to a kind of composite sand control type downhole slip type flow restrictor, uses double-layer composite sand control inner tube and sand control outer tube, different from traditional sand control cylinder or single sand control pipe structure, change gas mode, effectively block sand grain from gas well, not easy to cause sand jam or sand block, facilitate flow restrictor successfully salvage operation.

Description

Technical Field

[0001] This utility model relates to the field of downhole chokes in oil and gas fields, and in particular to a composite sand-proof downhole slip choke. Background Technology

[0002] To adapt to the vigorous development of gas fields, downhole choke technology has been widely applied as a core process in gas field development. In gas well production, the downhole choke is a key tool installed on the inner wall of the tubing, its core function being to choke and reduce the pressure of high-pressure natural gas deep within the wellbore. Market demand for chokes mainly focuses on products with high reliability, high retrieval success rate, and strong sand-blocking capabilities, especially new chokes adaptable to horizontal wells and high water-cut gas wells. Slip-type chokes have a wider range of applications due to their ability to withstand higher pressure differentials, good sealing effect, and simple and reliable deployment and retrieval operations. However, the sand-blocking performance of conventional slip-type chokes on the market varies greatly. If the choke itself has an unsatisfactory sand-blocking effect, it can lead to sand burial or sand jamming at the top of the choke, ultimately causing retrieval difficulties.

[0003] To address this issue, we designed a composite sand-resistant downhole slip-type choke to solve the problems existing in chokes on the market. Utility Model Content

[0004] To solve the above-mentioned technical problems, this utility model provides a composite sand-proof downhole slip-type throttle, which adopts a double-layer composite sand-proof inner tube and sand-proof outer tube, which is different from the traditional sand-proof cylinder or single sand-proof pipe structure. It changes the gas flow method, effectively blocking sand particles from the gas well, making it less likely to cause sand jamming or sand blockage, and facilitating the smooth retrieval operation of the throttle.

[0005] The technical solution adopted by this utility model to solve its technical problem is: a composite sand-proof downhole slip-type choke, including a composite sand-proof structure; the composite sand-proof structure includes a pipe seat set at the bottom end of the slip-type choke, a sand-proof outer pipe installed on the bottom side of the pipe seat, and a sand-proof inner pipe installed on the bottom side of the pipe seat and located inside the sand-proof outer pipe; the bottom ends of the sand-proof outer pipe and the bottom ends of the sand-proof inner pipe are both blind ends; the side wall of the sand-proof outer pipe is provided with a plurality of first sand-proof slots evenly distributed along the length direction; the side wall of the sand-proof inner pipe is provided with a plurality of second sand-proof slots evenly distributed along the length direction; the areas where the plurality of first sand-proof slots are located correspond to the areas where the plurality of second sand-proof slots are located.

[0006] Furthermore, the depth direction of the first sand-proof groove is at 45° to the axis of the outer sand-proof tube, and it is inclined from top to bottom and from the inside to the outside; the depth direction of the second sand-proof groove is at 45° to the axis of the inner sand-proof tube, and it is inclined from top to bottom and from the inside to the outside.

[0007] Furthermore, the width of the first sand-proof slot and the second sand-proof slot is 0.2mm-0.6mm; the width of the first sand-proof slot and the width of the second sand-proof slot are set according to the particle size distribution of the downhole geological sand.

[0008] Furthermore, the throttle valve includes a throttle nozzle assembly disposed near the bottom side; the throttle nozzle assembly includes a nozzle seat, and the nozzle seat includes a mounting portion; the mounting portion has a mounting cavity, which is threadedly connected to the lower region of the outer wall of the nozzle seat.

[0009] Furthermore, a threaded hole is provided on the side wall of the mounting part of the tube seat, and a first set screw is fitted into the threaded hole. The first set screw abuts against the outer wall of the air nozzle seat.

[0010] Furthermore, the tube seat also includes a first boss disposed on the bottom side of the mounting portion and a second boss disposed on the bottom side of the first boss; the first boss and the second boss have a channel that connects with the air nozzle seat; the outer diameter of the second boss is larger than the diameter of the channel and smaller than the outer diameter of the first boss.

[0011] Furthermore, the outer wall of the first boss is threaded to the top end of the inner wall of the sandproof outer tube; the outer wall of the second boss is threaded to the top end of the inner wall of the sandproof inner tube.

[0012] The beneficial effects of this utility model are as follows: This utility model is a composite sand-proof downhole slip-type throttle, which adopts a double-layer composite sand-proof inner tube and sand-proof outer tube. It is different from the traditional sand-proof cylinder or single sand-proof pipe structure. It changes the gas transmission method, effectively blocks sand particles from the gas well, and is less likely to cause sand jamming or sand blockage, which facilitates the smooth retrieval operation of the throttle. Attached Figure Description

[0013] Figure 1 A schematic diagram of a composite sand-control type downhole slip throttle device as an example;

[0014] Figure 2 A schematic diagram of the composite sand-control structure of a composite sand-control type downhole slip throttle as an example;

[0015] Figure 3 A schematic diagram of the pipe seat of a composite sand-control type downhole slip throttle as an embodiment;

[0016] Figure 4 A schematic diagram of the sand-proof outer tube of a composite sand-proof type downhole slip throttle device as an example;

[0017] Figure 5 A schematic diagram of the sand-proof inner tube of the composite sand-proof structure of a composite sand-proof downhole slip-type throttle device as an example;

[0018] Figure 6 for Figure 2 A magnified view of a portion of region D;

[0019] Figure 7 for Figure 1 A magnified view of a portion of region A;

[0020] Figure 8 for Figure 1 A magnified view of a portion of region B;

[0021] Figure 9 for Figure 1 A magnified view of a portion of region C;

[0022] Among them, 1-composite sand-proof structure, 2-dispensing head, 3-retrieval head, 4-dispensing pin, 5-connector, 6-mandrel, 7-second set screw, 8-upper retaining ring, 9-supporting ring, 10-third set screw, 11-shearing ring, 12-fourth set screw, 13-unsealing shear pin, 14-first sealing ring, 15-central tube, 16-clip, 17-cone, 18-sealing sleeve, 19-lower retaining ring, 20-locking ring sleeve, 21-locking ring, 22-connector 23-Nut, 24-Back Cap, 25-Fifth Set Screw, 26-Air Nozzle Seat, 27-Sixth Set Screw, 28-Second Sealing Ring, 29-Air Nozzle, 30-Third Sealing Ring, 31-First Set Screw, 101-Pipe Seat, 102-Sand-proof Outer Tube, 103-Sand-proof Inner Tube, 1011-Mounting Part, 1012-First Boss, 1013-Second Boss, 1021-First Sand-proof Gap Groove, 1031-Second Sand-proof Gap Groove. Detailed Implementation

[0023] To enhance understanding of this utility model, it will be described in further detail below with reference to the accompanying drawings and embodiments. These embodiments are only used to explain this utility model and do not limit the scope of protection of this utility model.

[0024] Example

[0025] Please refer to Figures 1 to 9As shown, a composite sand-control type downhole slip-type choke in this embodiment includes a composite sand-control structure 1; the composite sand-control structure 1 includes a pipe seat 101 disposed at the bottom end of the slip-type choke, a sand-control outer pipe 102 installed on the bottom side of the pipe seat 101, and a sand-control inner pipe 103 installed on the bottom side of the pipe seat 101 and located inside the sand-control outer pipe 102; the bottom ends of the sand-control outer pipe 102 and the bottom ends of the sand-control inner pipe 103 are both blind ends; the side wall of the sand-control outer pipe 102 is provided with a plurality of first sand-control slots 1021 equidistantly distributed along the length direction; the side wall of the sand-control inner pipe 103 is provided with a plurality of second sand-control slots 1031 equidistantly distributed along the length direction; the areas where the plurality of first sand-control slots 1021 are located correspond to the areas where the plurality of second sand-control slots 1031 are located.

[0026] Please refer to the following: Figures 4 to 6 As shown, the groove depth direction of the first sand-proof groove 1021 is at 45° to the axis of the outer sand-proof tube 102, and is inclined from top to bottom and from the inside to the outside; the groove depth direction of the second sand-proof groove 1031 is at 45° to the axis of the inner sand-proof tube 103, and is inclined from top to bottom and from the inside to the outside.

[0027] In this embodiment, the width of the first sand-proof groove 1021 and the second sand-proof groove 1031 is 0.2mm-0.6mm; the width of the first sand-proof groove 1021 and the width of the second sand-proof groove 1031 are set according to the particle size distribution of the downhole geological sand.

[0028] Please refer to the following: Figure 1 , Figure 3 and Figure 9 As shown, the throttle valve includes a throttle nozzle assembly disposed near the bottom side; the throttle nozzle assembly includes a nozzle seat 26, and the pipe seat 101 includes a mounting portion 1011; the mounting portion 1011 has a mounting cavity, which is threadedly connected to the lower region of the outer wall of the nozzle seat 26.

[0029] Please refer to the following: Figure 9 As shown, a threaded hole is also provided on the side wall of the mounting part 1011 of the tube seat 101, and a first set screw 31 is fitted in the threaded hole. The first set screw 31 abuts against the outer wall of the air nozzle seat 26.

[0030] Please refer to the following: Figure 3 As shown, the tube seat 101 further includes a first boss 1012 disposed on the bottom side of the mounting part 1011 and a second boss 1013 disposed on the bottom side of the first boss 1012; the first boss 1012 and the second boss 1013 have a channel that connects with the air nozzle seat 26; the outer diameter of the second boss 1013 is larger than the diameter of the channel and smaller than the outer diameter of the first boss 1012.

[0031] In this embodiment, the outer wall of the first boss 1012 is threaded to the top end of the inner wall of the sandproof outer tube 102; the outer wall of the second boss 1013 is threaded to the top end of the inner wall of the sandproof inner tube 103.

[0032] Please refer to the following: Figure 1 , Figures 7 to 9As shown, a composite sand-control type downhole slip throttle in this embodiment also includes a delivery head 2, a retrieval head 3, a delivery pin 4, a connector 5, a spindle 6, a second set screw 7, an upper retaining ring 8, a support ring 9, a third set screw 10, a shearing ring 11, a fourth set screw 12, a release shearing pin 13, a first sealing ring 14, a central tube 15, slips 16, a cone 17, a sealing sleeve 18, a lower retaining ring 19, a locking ring sleeve 20, a locking ring 21, a connecting sleeve 22, a nut 23, a back cap 24, a fifth set screw 25, a nozzle seat 26, a sixth set screw 27, a second sealing ring 28, a nozzle 29, a third sealing ring 30, and a first set screw 31; each part is placed horizontally on the workbench for assembly. For the assembled throttle, the following descriptions of "bottom" and "top" are based on the throttle being placed vertically: The inner hole of the upper retaining ring 8 is fitted onto the outer circumference of the middle section of the retrieval head 3. The internal thread of the shearing ring 11 is connected to the external thread near the bottom of the retrieval head 3, and the fourth set screw 12 is tightened at the internal and external threads. Then, the bottom end of the retrieval head 3 is fitted onto the outer circumference of one end of the mandrel 6 and moved until the external thread end of the top side of the mandrel 6 is exposed. The internal thread end of the bottom side of the connector 5 is threaded and tightened to the external thread end of the top side of the mandrel 6, and the second set screw 7 is tightened. The top end of the connector 5 is fitted onto the bottom end of the delivery head 2, the side hole of the connector 5 corresponds to the side hole of the delivery head 2, and the delivery pin 4 is installed therein. Move the retrieval head 3 to the middle section of the deployment head 2; embed three identical first sealing rings 14 into the large outer cylindrical sealing groove of the mandrel 6; fit the central tube 15 onto the mandrel 6, with the top end (claw spring end) of the central tube 15 fitted onto the bottom outer circle of the retrieval head 3; move the support ring 9 from the central tube 15 to the top end of the central tube 15, so that the top end of the central tube 15 is tightly gripped at the bottom end of the retrieval head 3; tighten the support ring 9 by connecting it to the external thread at the bottom end of the upper retaining ring 8 via the internal thread, and tighten the third set screw 10; simultaneously, align the side hole of the support ring 9 with the side hole of the shearing ring 11, and install the unsealing shearing nail 13 therein; fit the cone 17 onto the outer cylindrical section of the central tube 15, and install the top end of the slip 16 onto the T-shaped part at the bottom side of the support ring 9. In the groove, the inner side of the slip 16 is engaged with the limiting step of the central tube 15; the dovetail groove on the inner inclined surface of the bottom end of the slip 16 matches and is installed with the dovetail edge on the outer conical surface of the cone 17; two sealing rubber tubes 18 are successively fitted onto the outer cylinder of the central tube 15, with the top of the two sealing rubber tubes 18 on opposite top sides contacting the bottom end face of the cone 17; the lower retaining ring 19 is fitted onto the central tube 15, with the top of the lower retaining ring 19 abutting against the bottom end face of the two sealing rubber tubes 18 on opposite bottom sides; the locking ring sleeve 20 is fitted onto the central tube 15 and placed inside the lower retaining ring 19; then the locking ring 21 is fitted onto the central tube 15 and inserted into the inner hole of the locking ring sleeve 20, with the inner teeth of the locking ring 21 matching the outer teeth of the bottom outer wall of the central tube 15;The connecting sleeve 22 is fitted onto the central tube, with its top end inserted between the locking ring sleeve 20 and the lower retaining ring 19. The outer side of the top end of the connecting sleeve 22 is threadedly connected to the inner side of the bottom end of the lower retaining ring 19 and tightened. The stepped surface on the inner side of the connecting sleeve 22 abuts against the bottom end face of the locking ring 21. The nut 23 and the back cap 24 are fitted onto the central tube 15, with the top end of the nut 23 abutting against the bottom end of the connecting sleeve 22. The inner side of the top end of the back cap 24 is threadedly connected to the outer side of the bottom end of the connecting sleeve 22 and tightened, and the fifth set screw 25 is tightened. The sealing groove near the top end of the air nozzle seat 26 is fitted with the second sealing ring 28, and the sealing groove near the bottom end is fitted with the third sealing ring 30. The air nozzle seat 26 is fitted onto the spindle 6, and the second sealing ring 28 is inserted into the sealing groove near the top end of the air nozzle seat 26. The sealing ring 28 seals against the spindle 6; the inner side of the top of the nozzle seat 26 is threadedly connected to the outer side of the bottom of the back cap 24, and the sixth set screw 27 is tightened; the nozzle 29 is installed in the area near the bottom of the nozzle seat 26; the sand-proof inner tube 103 and the sand-proof outer tube 102 are sequentially threaded onto the second boss 1013 and the first boss 1012 of the tube seat 101; then the tube seat 101 is fitted onto the nozzle seat 26, and the inner wall of the mounting cavity of the mounting part 1011 of the tube seat 101 is threadedly connected to the outer wall of the bottom of the nozzle seat 26, and the first set screw 31 is tightened; finally, all exposed set screws are tightened again to prevent the threads from loosening, thus completing the assembly of the slip-type throttle.

[0033] This embodiment of a composite sand-control type downhole slip choke is operated via wire rope for deployment, setting, and retrieval. Specifically:

[0034] Deployment: Before setting, the slips are loosened and the sealing sleeve is in a naturally contracted state; then, the slip-type throttle is lowered into the designed position in the well. After setting, the deployment tool is released, the slips are opened and sit in the tubing, the sealing sleeve is opened and set, and a certain pressure difference is formed above and below the air nozzle. The pressure difference makes the throttle set more and more firmly.

[0035] Setting: After the choke is lowered to the predetermined position in the well, wait a few minutes and record the tension value. Then, quickly pull it up. As the tension count rises, continue to pull up the wireline, controlling the tension value. Repeat the lowering and pulling actions. Pay attention to the changes in the tension count value during lowering. The choke is released by repeated vibrations during lowering and pulling. As the wireline moves upward, only the release head is pulled out of the wellbore, while the rest of the choke remains in the wellbore. The choke is successfully set.

[0036] Salvage: Replace the drop tool with a retrieval tool, connect the tool string and lower it into the well. When the retrieval tool grabs the retrieval head of the downhole choke, lift it up to cut off the unsealing pin. Continue lifting to loosen the slips and cone, while the sealing rubber sleeve contracts. Continue lifting to retrieve the downhole choke.

[0037] In this embodiment, a composite sand control structure is designed, which differs from traditional sand control cylinders or single sand control pipes. The pipe base is connected to a double-layered composite sand control structure consisting of an inner sand control pipe and an outer sand control pipe. The gas flow method is changed; the bottom ends of both the inner and outer sand control pipes are designed as blind ends, and equidistant sand control slots (0.2mm~0.6mm width) at 45° to the axis are designed on their side walls, evenly distributed axially and radially, forming a composite double-layer sand control. Different inner and outer slot widths can be customized and adjusted according to the downhole geological sand particle conditions, effectively blocking sand particles from the gas well, reducing the risk of sand jamming or blockage, and facilitating smooth retrieval operations of the choke. Field testing on multiple gas wells has shown that it has stronger sand control capabilities than traditional chokes.

[0038] The above embodiments should not limit the present invention in any way. All technical solutions obtained by equivalent substitution or equivalent conversion fall within the protection scope of the present invention.

Claims

1. A composite sand-proof downhole slip-type throttle, characterized in that: The system includes a composite sand-proof structure (1); the composite sand-proof structure (1) includes a pipe seat (101) disposed at the bottom of the slip-type throttle, a sand-proof outer pipe (102) installed on the bottom side of the pipe seat (101), and a sand-proof inner pipe (103) installed on the bottom side of the pipe seat (101) and located inside the sand-proof outer pipe (102); the bottom ends of the sand-proof outer pipe (102) and the sand-proof inner pipe (103) are both blind ends; the side wall of the sand-proof outer pipe (102) is provided with a plurality of first sand-proof slots (1021) equidistantly distributed along the length direction; the side wall of the sand-proof inner pipe (103) is provided with a plurality of second sand-proof slots (1031) equidistantly distributed along the length direction; the area where the plurality of first sand-proof slots (1021) are located corresponds to the area where the plurality of second sand-proof slots (1031) are located.

2. The composite sand-control type downhole slip throttle according to claim 1, characterized in that: The first sand-proof groove (1021) is 45° to the axis of the outer sand-proof tube (102) and is inclined from top to bottom and from inside to outside; the second sand-proof groove (1031) is 45° to the axis of the inner sand-proof tube (103) and is inclined from top to bottom and from inside to outside.

3. A composite sand-control type downhole slip throttle according to claim 1 or 2, characterized in that: The width of the first sand-proof slot (1021) and the second sand-proof slot (1031) is 0.2mm-0.6mm; the width of the first sand-proof slot (1021) and the width of the second sand-proof slot (1031) are set according to the particle size distribution of the downhole geological sand.

4. The composite sand-control type downhole slip throttle according to claim 1, characterized in that: The throttle valve includes a throttle nozzle assembly disposed near the bottom side; the throttle nozzle assembly includes a nozzle seat (26), and the pipe seat (101) includes a mounting portion (1011); the mounting portion (1011) has a mounting cavity, which is threaded to the lower region of the outer wall of the nozzle seat (26).

5. A composite sand-control type downhole slip throttle according to claim 4, characterized in that: The mounting portion (1011) of the tube seat (101) is also provided with a threaded hole, which is fitted with a first set screw (31), and the first set screw (31) abuts against the outer wall of the air nozzle seat (26).

6. A composite sand-control type downhole slip throttle according to claim 4 or 5, characterized in that: The tube seat (101) further includes a first boss (1012) disposed on the bottom side of the mounting part (1011) and a second boss (1013) disposed on the bottom side of the first boss (1012); the first boss (1012) and the second boss (1013) have a channel that connects with the air nozzle seat (26); the outer diameter of the second boss (1013) is larger than the diameter of the channel and smaller than the outer diameter of the first boss (1012).

7. A composite sand-control type downhole slip throttle according to claim 6, characterized in that: The outer wall of the first boss (1012) is threaded to the top end of the inner wall of the sandproof outer tube (102); the outer wall of the second boss (1013) is threaded to the top end of the inner wall of the sandproof inner tube (103).

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