CN111502595A - All metal sealed soluble bridge plug - Google Patents

Abstract

The invention belongs to the field of downhole tools in oilfields, and in particular relates to an all-metal sealed dissolvable bridge plug, comprising a center pipe, an upper outer pipe and a lower outer pipe are sheathed in sequence on the center pipe, and an annular space is left between the upper outer pipe and the center pipe , in the annular space, there are two pistons on the upper and lower sides, namely piston A and piston B, wherein piston A is fixed and sealed with the central tube, and is connected with the upper outer tube in a sliding seal. The inner side of the upper outer tube of the piston B section has a The diameter expansion step plays a limiting role on the piston B, the piston B is connected with the upper outer tube in a sliding seal, and the piston B is connected with the center tube in a sliding seal, so that the piston A, the piston B, the center tube and the upper outer tube are surrounded by A gas chamber is formed into a gas chamber, which is called the upper gas chamber. The present invention uses the fluid to drive the hydrodynamic rotary paddle to convert the rotary motion into axial movement, thereby opening the liquid passage, so that the two gas chambers are compressed by the powerful hydraulic pressure in the well, thereby A reverse force is generated to set the bridge plug.

Description

All metal sealed soluble bridge plug

technical field

The invention belongs to the field of downhole tools in oilfields, in particular to an all-metal sealed soluble bridge plug.

Background technique

Bridge plugs are downhole tools used to temporarily isolate the wellbore in the staged fracturing technology of horizontal wells. According to the different ways of unsealing, bridge plugs can be divided into removable bridge plugs, drillable bridge plugs and soluble bridge plugs. The salvage cost of the salvageable bridge plug is high, and the risk of failure is high; when the amount of debris generated by the drillable bridge plug during drilling and milling is large, it will accumulate and block the casing, which will have adverse effects on subsequent operations; the soluble bridge plug is made of magnesium and aluminum alloys. A new type of bridge plug, which can dissolve in a certain liquid environment after the completion of the fracturing operation, so as to realize the full-bore production of the wellbore.

In the prior art, the rubber cylinder in the bridge plug is relatively thick, and the diameter of the bridge plug is fixed. Therefore, the rubber cylinder seriously restricts the expansion of the diameter of the bridge plug, thereby limiting the performance of the bridge plug; in addition, installing the bridge plug In this case, it is necessary to connect a special setting tool for the bridge plug above the bridge plug. The length of the tool section formed by connecting the setting tool and the bridge plug into one body is long, and the problem of sticking is easy to occur during the downhole process. It is therefore necessary to design a soluble bridge plug that does not require setting tools.

SUMMARY OF THE INVENTION

In order to solve the problem in the background art that the sealing component of the bridge plug is thicker, which affects the expansion of the diameter of the bridge plug, and the problem that the setting tool of the bridge plug is required to cause the pipe string to be too long in the background art, the present invention provides an all-metal seal. Dissolving bridge plug, the sealing assembly of the present invention is a relatively thin metal sealing ring, and the present invention does not require a setting tool after reaching the predetermined position, so the length of the pipe string is short, and the probability of sticking is reduced.

The technical scheme provided by the present invention is: an all-metal sealing dissolvable bridge plug, comprising a central tube, a vertebral body and slips, the central tube and the vertebral body are threadedly connected, and the slips are sleeved on the central tube and the vertebral body. On the outside of the body, the relative movement of the vertebral body and the slip makes the claw of the slip expand and finally get stuck on the inner wall of the casing, and the outside of the claw is provided with a ceramic column, which is characterized in that: the present invention also includes a metal sealing ring. The metal sealing ring is sleeved on the vertebral body, and the upper end of the slip abuts on the metal sealing ring;

The center tube under the slip is sleeved with an orientation ring, a support ring, an upper outer tube and a lower outer tube in sequence, and the four are connected in sequence;

The inner side of the lower part of the orientation ring is provided with a circlip, the supporting ring is located below the circlip and is used to support the circlip, and the outer side of the center tube corresponding to the circlip section is processed with a clamping tooth that restricts the downward movement of the circlip relative to the center tube, thereby The support ring, the circlip and the directional ring as a whole can only move upward relative to the central tube;

An annular space is left between the upper outer tube and the central tube, and two pistons are arranged in the annular space, namely piston A and piston B, wherein piston A is fixed and sealed with the central tube, and is connected with the upper outer tube. Sliding and sealing connection, the inner side of the upper outer tube of the piston B section is provided with a diameter expansion step, and the diameter expansion step acts as a limit for the piston B, the piston B is connected with the upper outer tube in a sliding seal, and the piston B is connected with the center tube in a sliding seal, thus Piston A, piston B, central tube, and upper outer tube form a gas chamber, which is called the upper gas chamber;

An annular space is left between the lower outer tube and the central tube, and two pistons on the upper and lower sides are arranged in the annular space, which are piston C and piston D respectively. Pipe sliding and sealing connection, piston D is fixed and sealing connection with the lower outer pipe, and sliding and sealing connection with the center pipe, so that the piston C, piston D, center pipe, and lower outer pipe form a gas chamber, which is called the lower gas chamber;

The inner side of the central tube is divided into an upper diameter expansion section and a lower diameter reduction section, and a hydrodynamic rotating paddle is installed in the expanding diameter section. The hydrodynamic rotating paddle is coaxial with the central tube, and the hydrodynamic rotating paddle shaft is connected with a The helical gear has two coaxial holes on the center tube between the piston B and the piston C, the valve cores are respectively installed in the two holes, and a valve meshing with the helical gear is connected between the two valve cores. screw, so as to convert the rotational movement of the helical gear into the axial movement of the screw. One of the valve cores is provided with an axial blind hole and a radial through hole, and the axial blind hole and the radial through hole are connected to form a connection between the inside and outside of the central pipe. Liquid passage, the axial movement of the valve core controls the opening and closing of the liquid passage;

The valve core is vulcanized with a soft layer of soluble rubber;

The outer side of the upper end of the vertebral body is provided with a reduced diameter section, the outer side of the reduced diameter section is slidably sealed with the coiled tubing, and the two are connected by hand-dropping scissors.

Further, the two sides of the hydrodynamic rotating paddle are respectively provided with retaining rings for limiting them.

Further, the vertebral body above the metal sealing ring is sheathed with a sealing spacer ring for limiting the position thereof.

Further, the piston A and the piston C are formed by splicing two half rings, the outer side of the central tube of the section where the piston A and the piston C are located are processed with an annular groove, and the piston A and the piston C are installed in the annular groove. in the groove.

The beneficial effects of the present invention are:

The sealing component in the present invention is a metal sealing ring. Compared with the traditional rubber sealing component, the metal sealing ring is thinner, which improves the expandability of the diameter of the bridge plug.

After the invention reaches the predetermined position, the hydrodynamic rotary paddle is rotated by the coiled tubing pressure, and the rotary motion of the helical gear is converted into the axial motion of the screw, so as to open the liquid passage, and under the action of strong hydraulic pressure in the well, the two compressed air chambers, thereby creating opposing forces on the two pistons of each air chamber, which pull the center tube and the two outer tubes in reverse, thereby expanding the slips and anchoring them to the casing wall. Therefore, after the present invention reaches the predetermined position, self-setting can be realized without using setting tools, thereby shortening the length of the pipe string, thereby avoiding sticking due to the long pipe string in the running horizontal well.

Description of drawings

Figure 1 is a schematic structural diagram of the present invention.

FIG. 2 is a cross-sectional view at A-A in FIG. 1 .

FIG. 3 is a cross-sectional view at B-B in FIG. 1 .

FIG. 4 is a partial enlarged view of C in FIG. 1 .

In the picture: 1-coiled tubing, 2-hand-drop scissors, 3-vertebral body, 4-sealing spacer, 5-metal sealing ring, 6-center tube, 7-slip, 8-orientation ring, 9-torsion Ring, 10-circlip, 11-upper outer tube, 12-lower outer tube, 13-piston D, 14-lower air chamber, 15-piston C, 16-piston B, 17-upper air chamber, 18-piston A , 19- blocking ring, 20- hydrodynamic rotary paddle, 21- helical gear, 22- screw, 23- valve core, 24- liquid passage.

Detailed ways

In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

The present invention includes a central tube 6, a vertebral body 3 and slips 7, the central tube 6 is connected with the vertebral body 3 by thread, the slips 7 are sleeved on the outer side of the central tube 6 and the vertebral body 3, and the vertebral body 3 is connected with the vertebral body 3. The relative movement of the slips 7 causes the jaws of the slips 7 to expand and finally get stuck on the inner wall of the casing. The outer side of the jaws is provided with a ceramic column.

The main innovation of the present invention is:

The present invention also includes a metal seal ring 5, the metal seal ring 5 is sleeved on the vertebral body 3, and the upper end of the slip 7 abuts on the metal seal ring 5. The metal seal ring 5 in the present invention replaces the traditional The thickness of the metal sealing ring 5 is smaller than that of the rubber sealing assembly, so it is more conducive to improving the expansion of the diameter of the bridge plug.

The center tube 6 below the slip 7 is sleeved with an orientation ring 8, a support ring 9, an upper outer tube 11 and a lower outer tube 12 in sequence, and the four are screwed in sequence.

The inner side of the lower part of the orientation ring 8 is provided with a circlip 10, the supporting ring 9 is located below the circlip 10 for supporting the circlip 10, and the outer side of the center tube 6 corresponding to the circlip 10 is processed with a limit circlip 10 opposite. The downward clamping teeth of the central tube 6 , so the support ring 9 , the retaining ring 10 and the orientation ring 8 as a whole can only move upward relative to the central tube 6 .

An annular space is left between the upper outer tube 11 and the central tube 6, and two pistons are arranged in the annular space, which are piston A18 and piston B16, wherein the piston A18 is fixed and sealed with the central tube 6, and is The upper outer tube 11 is slidably and sealedly connected, and the inner side of the upper outer tube 11 of the piston B16 section is provided with a diameter expansion step, which limits the position of the piston B16. The pipes 6 are connected in a sliding and sealing manner, so that the piston A18 , the piston B16 , the central pipe 6 and the upper outer pipe 11 form a gas chamber, which is called the upper gas chamber 17 .

When the upper air chamber 17 is subjected to the liquid pressure from the downhole, the upper air chamber 17 is compressed, and the piston A18 and the piston B16 are close to each other. The outer tube 11 exerts an upward thrust, so that two reaction forces finally act between the slips 7 and the vertebral body 3, so that the slips 7 are expanded and finally stuck on the inner wall of the casing.

An annular space is left between the lower outer tube 12 and the central tube 6, and two pistons on the upper and lower sides are arranged in the annular space, namely the piston C15 and the piston D13, wherein the piston C15 is fixed and sealed with the central tube 6, It is slidably and sealedly connected to the lower outer tube 12, the piston D13 is fixedly and sealedly connected to the lower outer tube 12, and is slidably and sealedly connected to the central tube 6, so that the piston C15, the piston D13, the central tube 6, and the lower outer tube 12 form a gas chamber. The chamber is called the lower air chamber 14 .

When the lower air chamber 14 is subjected to the liquid pressure from the downhole, the lower air chamber 14 is compressed, and the same reverse force as the upper air chamber 17 to set the bridge plug is generated. The greater the sealing force, the better the setting effect.

The inner side of the central tube 6 is divided into an upper diameter expansion section and a lower diameter reduction section, and a hydrodynamic rotating paddle 20 is installed in the expanding diameter section, and the hydrodynamic rotating paddle 20 is coaxial with the central tube 6. After it is in place, the coiled tubing 1 is pressed, and the liquid flows through to make the hydrodynamic rotary paddle 20 rotate. Two coaxial holes are opened on the central pipe 6 between the piston B16 and the piston C15, the valve cores 23 are respectively installed in the two holes, and a valve core 23 is connected with the helical gear 21. The screw 22 is connected, so as to convert the rotational movement of the helical gear 21 into the axial movement of the screw 22. The length of the thread meshing with the helical gear 21 on the screw 22 is limited, so even if the helical gear 21 is always rotating in one direction, the axial direction of the screw 22 is limited. The displacement is also fixed, but the helical gear 21 loses meshing on the screw 22 and spins idly. One of the valve cores 23 is provided with an axial blind hole and a radial through hole. The axial blind hole and the radial through hole are connected to form a liquid passage 24. The axial movement of the valve core 23 controls the opening and closing of the liquid passage 24. .

In order to ensure the tightness between the valve core 23 and the hole, a soluble rubber soft layer is vulcanized on the valve core 23 .

The outer side of the upper end of the vertebral body 3 is provided with a diameter-reduced section, and the outer side of the reduced-diameter section is slidably sealed with the coiled tubing 1, and the two are connected by hand-throwing scissors 2. After the bridge plug is set and sealed, the coiled tubing 1 is lifted up. , the hand-dropping scissors 2 with low strength are cut off, that is, hand-dropping is realized. The invention does not need to connect a special setting tool when setting, so the length of the pipe string is short, and the occurrence of jamming accident is effectively reduced when running into a horizontal well, and when the bridge plug is lowered, the coiled tubing 1 pushes the bridge plug down, and the scissors 2 are lost. Not under force, so it won't break accidentally.

The two sides of the hydrodynamic rotary paddle 20 are respectively provided with retaining rings 19 for limiting the position thereof.

The vertebral body 3 above the metal sealing ring 5 is sheathed with a sealing spacer ring 4 that acts as a limiter.

The piston A18 and the piston C15 are both formed by splicing two half rings. The outer side of the central tube 6 of the section where the piston A18 and the piston C15 are located is processed with an annular groove, and the piston A18 and the piston C15 are installed in the annular groove. Inside.

All components except the ceramic column in the present invention are made of soluble materials, and after fracturing, the present invention dissolves by itself to restore the full diameter of the casing.

The present invention is especially suitable for fracturing horizontal wells. Before fracturing, the present invention is connected to the lower end of the coiled tubing 1 into the well. During the feeding process, the well fluid passes through the hydrodynamic rotary paddle 20 from bottom to top, so that the hydrodynamic rotary paddle 20 generates The counterclockwise rotation causes the helical gear 21 to rotate counterclockwise, and the driving screw 22 moves axially to block the liquid passage 24; However, due to the limited length of the thread on the screw 22, the helical gear 21 loses engagement with the screw 22 and rotates idly, so that the screw 22 will not continue to undergo axial displacement. After the bridge plug is sent to the predetermined position, it presses the coiled tubing 1, and the liquid passes through the hydrodynamic rotary paddle 20 from top to bottom, so that the hydrodynamic rotary paddle 20 rotates clockwise, and the helical gear 21 follows to generate a clockwise rotation. , the driving screw 22 moves axially, and the liquid passage 24 is opened. With the continuous pressing, the hydrodynamic rotary paddle 20 continues to rotate clockwise. Also, because the thread length on the screw 22 is limited, the screw 22 will not continue to have axial displacement. , keep the liquid passage 24 open.

The present invention utilizes fluid to drive the hydrodynamic rotary paddle 20 to convert the rotary motion into axial movement, thereby opening the liquid passage 24, so that the two air cavities are compressed by the powerful hydraulic pressure in the well, thereby generating a reverse force, making the bridge plug sit seal up.

Claims (4)

1. The utility model provides an all-metal seal soluble bridge plug, includes center tube (6), centrum (3) and slips (7), center tube (6) and centrum (3) threaded connection, slips (7) cover in the outside of center tube (6) and centrum (3), centrum (3) and the relative motion of slips (7) make the jack catch expansion of slips (7) and finally block at the sleeve pipe inner wall, the jack catch outside has ceramic column, its characterized in that: the invention also comprises a metal sealing ring (5), wherein the metal sealing ring (5) is sleeved on the cone (3), and the upper end of the slip (7) is abutted against the metal sealing ring (5);

a central pipe (6) below the slips (7) is sequentially sleeved with an orientation ring (8), a supporting ring (9), an upper outer pipe (11) and a lower outer pipe (12), and the four are sequentially in threaded connection;

the clamp spring (10) is arranged on the inner side of the lower portion of the orientation ring (8), the support ring (9) is located below the clamp spring (10) and used for supporting the clamp spring (10), clamp teeth for limiting the clamp spring (10) to move downwards relative to the central tube (6) are machined on the outer side of the central tube (6) corresponding to the clamp spring (10), and therefore the support ring (9), the clamp spring (10) and the orientation ring (8) can only move upwards relative to the central tube (6) as a whole;

an annular space is reserved between the upper outer tube (11) and the central tube (6), an upper piston and a lower piston are arranged in the annular space and respectively comprise a piston A (18) and a piston B (16), wherein the piston A (18) is fixedly and hermetically connected with the central tube (6) and is in sliding sealing connection with the upper outer tube (11), the inner side of the upper outer tube (11) of the section of the piston B (16) is provided with an expanding step, the expanding step limits the piston B (16), the piston B (16) is in sliding sealing connection with the upper outer tube (11), and the piston B (16) is in sliding sealing connection with the central tube (6), so that the piston A (18), the piston B (16), the central tube (6) and the upper outer tube (11) enclose a gas chamber which is called as an upper gas chamber (17);

an annular space is reserved between the lower outer pipe (12) and the central pipe (6), two pistons, namely a piston C (15) and a piston D (13), are arranged in the annular space, wherein the piston C (15) is fixedly and hermetically connected with the central pipe (6) and is in sliding and sealing connection with the lower outer pipe (12), and the piston D (13) is fixedly and hermetically connected with the lower outer pipe (12) and is in sliding and sealing connection with the central pipe (6), so that a gas chamber, namely a lower gas chamber (14), is enclosed by the piston C (15), the piston D (13), the central pipe (6) and the lower outer pipe (12);

the inner side of the central tube (6) is divided into an upper expanding section and a lower reducing section, a hydrodynamic rotating paddle (20) is arranged in the expanding section, the hydrodynamic rotating paddle (20) is coaxial with the central tube (6), a helical gear (21) is connected on the shaft of the hydrodynamic rotating paddle (20), a central pipe (6) between the piston B (16) and the piston C (15) is provided with two coaxial holes, two valve cores (23) are respectively arranged in the two holes, a screw rod (22) meshed with the helical gear (21) is connected between the two valve cores (23), thereby converting the rotary motion of the helical gear (21) into the axial motion of the screw (22), one valve core (23) is provided with an axial blind hole and a radial through hole, the axial blind hole is communicated with the radial through hole to form a liquid passing channel (24) communicated with the inside and the outside of the central tube (6), and the axial movement of the valve core (23) controls the opening and the closing of the liquid passing channel (24);

a soluble rubber soft layer is vulcanized on the valve core (23);

the outer side of the upper end of the cone body (3) is provided with a reducing section, the outer side of the reducing section is in sliding seal with the coiled tubing, and the reducing section and the coiled tubing are connected through a releasing shear pin (2).

2. An all-metal sealed soluble bridge plug according to claim 1, wherein: two sides of the hydrodynamic rotating paddle (20) are respectively provided with a baffle ring (19) which has a limiting effect on the hydrodynamic rotating paddle.

3. An all-metal sealed soluble bridge plug according to claim 1, wherein: the vertebral body (3) above the metal sealing ring (5) is sleeved with a sealing spacer ring (4) which can limit the vertebral body.

4. An all-metal sealed soluble bridge plug according to claim 1, wherein: the piston A (18) and the piston C (15) are formed by splicing two semi-rings, an annular groove is processed on the outer side of a central pipe (6) of a section where the piston A (18) and the piston C (15) are located, and the piston A (18) and the piston C (15) are installed in the annular groove.

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