阅读说明：本技术 一种可增压坐封的扩张式封隔器及其使用方法 (But expanding packer of pressure boost setting and application method thereof ) 是由 孙德旭 王增林 孙金峰 罗杨 隋旭强 姜忠新 毛福生 王鹏飞 张凯 谭云贤 于 2019-11-11 设计创作，主要内容包括：本发明公开了一种可增压坐封的扩张式封隔器及其使用方法,属于扩张式封隔器领域,包括上连接头,上连接头连接有上挡碗,上挡碗连接有胶筒,胶筒内部套接有外中心管；胶筒的下端连接有下挡碗,下挡碗的下端连接有外筒,外筒的下部与下连接头连接；上连接头和下连接头之间设置有内中心管；外中心管与内中心管之间设置坐封液；内中心管上设置导液孔；外筒和内中心管之间设置增压部件。本发明通过设置增压部件,可使加压时坐封液压强较内中心管内压强增大数倍,解决了现有扩张式封隔器在低节流压差下无法有效坐封的问题,可满足低节流压差下坐封需求,达到更好的分层效果,防止层间流体和压力互相干扰,提高油井生产效率。(The invention discloses a pressurized setting expansion packer and a use method thereof, belonging to the field of expansion packers and comprising an upper connector, wherein the upper connector is connected with an upper retaining bowl which is connected with a rubber cylinder, and an outer central pipe is sleeved in the rubber cylinder; the lower end of the rubber cylinder is connected with a lower retaining bowl, the lower end of the lower retaining bowl is connected with an outer cylinder, and the lower part of the outer cylinder is connected with a lower connector; an inner central tube is arranged between the upper connector and the lower connector; setting sealing liquid between the outer central tube and the inner central tube; the inner central tube is provided with a liquid guide hole; and a pressurizing component is arranged between the outer cylinder and the inner central pipe. By arranging the pressurizing component, the setting hydraulic pressure is stronger than the pressure in the inner central tube by multiple times during pressurization, the problem that the existing expansion packer cannot be effectively set under low throttling differential pressure is solved, the setting requirement under the low throttling differential pressure can be met, a better layering effect is achieved, interlayer fluid and pressure are prevented from interfering with each other, and the production efficiency of an oil well is improved.)

1. The expandable packer capable of realizing pressurized setting is characterized by comprising an upper connector (1), wherein the upper connector (1) is connected with an upper retaining bowl (2), the upper retaining bowl (2) is connected with a rubber cylinder (3), an outer central pipe (4) is sleeved inside the rubber cylinder (3), and a plurality of pressure guide holes are uniformly distributed on the pipe side of the outer central pipe (4); the lower end of the rubber cylinder (3) is connected with a lower baffle bowl (6), the lower end of the lower baffle bowl (6) is connected with an outer cylinder (7), and the lower part of the outer cylinder (7) is connected with a lower connector (12); an inner central pipe (5) is arranged between the upper connector (1) and the lower connector (12), and the inner central pipe (5) is arranged on the inner side of the outer central pipe (4); a setting and sealing liquid is arranged between the outer central tube (4) and the inner central tube (5); the inner central tube (5) is provided with a liquid guide hole; a pressurizing component is arranged in an annular space between the outer cylinder (7) and the inner central tube (5); the pressurizing part comprises a first pressurizing piston (8), the first pressurizing piston (8) is of a hollow structure, one end of the first pressurizing piston is a small section end, the other end of the first pressurizing piston is a large section end, the small section end is in contact with the setting liquid, and the large section end is in contact with the liquid injected into the inner central pipe (5).

2. the supercharged, set, expandable packer according to claim 1, characterized in that a collar (9) is arranged below the first supercharging piston (8), the collar (9) is sleeved between the outer barrel (7) and the inner central tube (5), the outer barrel (7) is provided with a groove in which the collar (9) can be clamped and positioned, the collar (9) is provided with a through hole; an annular space A (13) is formed among the first pressurizing piston (8), the retainer ring (9), the inner central tube (5) and the outer cylinder (7).

3. A pressure-settable expandable packer according to claim 2, wherein the large-section end of the first pressure-increasing piston (8) is connected with a second pressure-increasing piston (10), the second pressure-increasing piston (10) mainly comprises a piston and a piston rod (101) fixedly mounted on the piston, the piston can slide in the space formed by the outer barrel (7) and the inner central tube (5), and the piston rod (101) passes through the through hole of the retainer ring (9) and is fixedly connected with the first pressure-increasing piston (8).

4. A supercharged, set expandable packer according to claim 3, characterized in that it further comprises a buffer device (11) arranged below the second booster piston (10), said buffer device (11) essentially comprising a buffer cylinder (111), a buffer spring (112) being arranged in said buffer cylinder (111), said buffer spring (112) being connected to a buffer slide (113), said buffer slide (113) being slidable in said buffer cylinder (111); an annular space B (14) is formed among the second pressurizing piston (10), the buffer device (11), the inner central tube (5) and the outer cylinder (7).

5. The supercharged setting expansion packer as claimed in claim 4, characterized in that the top, inner wall and outer wall of the buffer tube (111) are provided with a drain hole A (114), a drain hole B (115) and a drain hole C (116), respectively, the inner part of the outer tube (7) is provided with a through drain channel A (71), the drain channel A (71) is communicated with the annular space B (14) below the second supercharging piston (10), and the inner part of the buffer slide block (113) is provided with a through drain channel B (117); the liquid guide hole A (114) connects the space where the buffer spring (112) is located with the annular space B (14); the liquid guide hole B (115) is matched with the liquid guide hole of the inner central pipe (5), and the space at the lower part of the buffer cylinder (111) is communicated with the inside of the inner central pipe (5); two openings of the liquid guide hole C (116) are respectively matched with the liquid guide channel A (71) and the liquid guide channel B (117), and the liquid guide hole C (116) can communicate the liquid guide channel A (71) with the liquid guide channel B (117), so that the annular space B (14) is communicated with the space at the lower part of the buffer cylinder (111).

6. A method of pressure-setting based on the pressure-settable expandable packer of claim 1, comprising the steps of: in the process of going down the well, liquid in the inner central tube (5) flows into the lower part of the large-section end of the first pressurizing piston (8) through the liquid guide hole in the inner central tube (5), when the pressure of the liquid in the inner central tube (5) is stably increased, the pressure of the liquid below the first pressurizing piston (8) is increased, so that the first pressurizing piston (8) is pushed to move upwards to extrude setting liquid, the setting liquid pressure is increased, the pressure on the rubber cylinder (3) is increased, the rubber cylinder (3) expands radially to contact with a sleeve, and setting is completed.

7. A method of dual booster setting based on the booster-settable expandable packer of claim 5, comprising the steps of: in the process of descending the well, liquid in the inner central tube (5) flows into the annular space A (13) and the annular space B (14) through the liquid guide holes in the inner central tube (5), when the pressure of the liquid in the inner central tube (5) is stably increased, the pressure of the liquid below the first pressurizing piston (8) and the second pressurizing piston (10) is increased, so that the first pressurizing piston (8) and the second pressurizing piston (10) are pushed to move upwards simultaneously to squeeze setting liquid, the setting liquid pressure is increased, the pressure applied to the rubber cylinder (3) is increased, the rubber cylinder (3) is radially expanded to be in contact with a casing, and setting is completed.

8. A method of anti-advancing setting based on the pressurizable set expandable packer of claim 5, comprising the steps of: during the downhole process, the liquid inside the inner central tube (5) flows into the annular space A (13) and the annular space B (14) through the liquid guide holes on the inner central tube (5) respectively, when the pressure of the liquid in the inner central tube (5) is increased instantly, a larger pressure difference is generated above and below the buffer sliding block (113), the buffer sliding block (113) is pushed upwards, the pushing force makes the buffer slide block (113) move upwards to compress the buffer spring (112), the cross-sectional area of the liquid guide passage B (117) communicating with the liquid guide hole C (116) is gradually reduced, the flow rate of the liquid flowing into the annular space B (14) is reduced, the boosting piston (10) is displaced upwards slightly, and the buffer spring (112) absorbs part of energy in the process, so that the instantaneous setting liquid cannot reach the pressure required by setting; when the pressure increased instantly disappears, the pressure difference above and below the buffer slide block (113) disappears, the buffer spring (112) pushes the buffer slide block (113) to return to the initial position, and the first pressurizing piston (8) and the second pressurizing piston (10) return downwards.

9. a method of using the pressurizable set expandable packer of claim 5, comprising the steps of:

In the process of descending the well, liquid in the inner central tube (5) flows into the annular space A (13) and the annular space B (14) through liquid guide holes in the inner central tube (5), when the pressure of the liquid in the inner central tube (5) is stably increased, the pressure of the liquid below the first pressurizing piston (8) and the second pressurizing piston (10) is increased, so that the first pressurizing piston (8) and the second pressurizing piston (10) are pushed to move upwards simultaneously to squeeze setting sealing liquid, the setting sealing liquid pressure is increased, the pressure applied to the rubber cylinder (3) is increased, the rubber cylinder (3) is radially expanded to be in contact with a casing, and setting sealing is completed;

When the pressure of liquid in the inner central tube (5) is increased instantly in the process of descending, a larger pressure difference is generated above and below the buffer slide block (113), the buffer slide block (113) is subjected to upward thrust, the thrust enables the buffer slide block (113) to move upwards to compress the buffer spring (112), the cross section area of the liquid guide channel B (117) communicated with the liquid guide hole C (116) is gradually reduced, the liquid flow flowing into the annular space B (14) is reduced, the boosting piston (10) moves upwards a little, and the buffer spring (112) absorbs part of energy in the process, so that the instant setting liquid cannot reach the pressure required by setting; when the pressure increased instantly disappears, the pressure difference above and below the buffer slide block (113) disappears, the buffer spring (112) pushes the buffer slide block (113) to return to the initial position, and the first pressurizing piston (8) and the second pressurizing piston (10) return downwards.

Technical Field

The invention relates to the field of an expandable packer, in particular to an expandable packer capable of being pressurized and set and a using method thereof.

Background

The implementation of polymer flooding and water injection well profile control in oilfield development is an effective means for solving the contradiction between water-flooding reservoir layer development and improving the water-flooding development effect, and is generally applied to the development of various large water-flooding oilfields at present. However, in the implementation process, the polymer solution and the profile control agent injected into the water well are mostly high-viscosity solution systems prepared from high molecular polymers, and if the throttling pressure difference is too large in the injection process, the long-chain structure of polymer molecules is damaged, so that the viscosity of the solution system is greatly reduced, the profile control and flooding performance of injected fluid is affected, and the oil displacement effect is reduced. Therefore, it is desirable to maintain a small throttle pressure differential during injection to ensure that the viscosity retention of the injected fluid meets performance requirements.

At present, an expansion packer is generally adopted as a layering tool for underground layering of a water injection well. Conventional expandable packers are set zonation by the pressure in the string acting directly on the packer, causing the packer to expand. However, the conventional expandable packer cannot be effectively set under low throttling differential pressure and cannot meet the layering requirement. Therefore, there is a need for improvements in the art to meet the setting requirements at low throttle differential pressures.

Disclosure of Invention

Aiming at the problems in the prior art, the invention aims to provide a pressurized setting expansion packer and a using method thereof, which can realize that the packer can keep a better setting effect under a lower throttling pressure difference and ensure underground stratification.

In order to achieve the purpose, the invention adopts the following technical scheme:

A pressure boosting setting expansion packer comprises an upper connector, wherein the upper connector is connected with an upper blocking bowl, the upper blocking bowl is connected with a rubber cylinder, an outer central pipe is sleeved inside the rubber cylinder, and a plurality of pressure guide holes are uniformly distributed on the pipe side of the outer central pipe; the lower end of the rubber cylinder is connected with a lower baffle bowl, the lower end of the lower baffle bowl is connected with an outer cylinder, and the lower part of the outer cylinder is connected with a lower connector; an inner central pipe is arranged between the upper connector and the lower connector, and the inner central pipe is arranged on the inner side of the outer central pipe; a setting liquid is arranged between the outer central pipe and the inner central pipe; the inner central tube is provided with a liquid guide hole; a pressurizing component is arranged in an annular space of the outer cylinder and the inner central pipe; the pressurizing part comprises a first pressurizing piston, the first pressurizing piston is of a hollow structure, one end of the first pressurizing piston is a small section end, the other end of the first pressurizing piston is a large section end, the small section end is in contact with the setting liquid, and the large section end is in contact with the liquid injected into the inner central tube.

furthermore, a check ring is arranged below the first supercharging piston, the check ring is sleeved between the outer cylinder and the inner central pipe, a groove is formed in the outer cylinder, the check ring can be clamped in the groove for positioning, and a through hole is formed in the check ring; an annular space A is formed among the first pressurizing piston, the retainer ring, the inner central tube and the outer barrel.

Furthermore, the large-section end of the first pressurizing piston is connected with a second pressurizing piston, the second pressurizing piston mainly comprises a piston and a piston rod fixedly installed on the piston, the piston can slide in a space formed by the outer cylinder and the inner central tube, and the piston rod penetrates through the through hole of the check ring and is fixedly connected with the first pressurizing piston.

Further, a buffer device is arranged below the second supercharging piston, the buffer device mainly comprises a buffer cylinder, a buffer spring is arranged in the buffer cylinder, the buffer spring is connected with a buffer slide block, and the buffer slide block can slide in the buffer cylinder; an annular space B is formed among the second pressurizing piston, the buffer device, the inner central pipe and the outer cylinder.

furthermore, a liquid guide hole A, a liquid guide hole B and a liquid guide hole C are respectively formed in the top, the inner wall and the outer wall of the buffer cylinder, a through liquid guide channel A is formed in the outer cylinder, the liquid guide channel A is communicated with an annular space B below the second pressurizing piston, and a through liquid guide channel B is formed in the buffer slide block; the liquid guide hole A connects the space where the buffer spring is located with the annular space B; the liquid guide hole B is matched with the liquid guide hole of the inner central pipe, and the space at the lower part of the buffer cylinder is communicated with the inside of the inner central pipe; two openings of the liquid guide hole C are respectively matched with the liquid guide channel A and the liquid guide channel B, and the liquid guide hole C can communicate the liquid guide channel A with the liquid guide channel B, so that the annular space B is communicated with the space at the lower part of the buffer cylinder.

A method of pressure-setting a pressure-settable expandable packer, comprising the steps of: in the process of going down the well, liquid in the inner central tube flows into the position below the large-section end of the first pressurizing piston through the liquid guide hole in the inner central tube, when the pressure of the liquid in the inner central tube is stably increased, the pressure of the liquid below the first pressurizing piston is increased along with the pressure of the liquid, so that the first pressurizing piston is pushed to move upwards to extrude setting liquid, the setting liquid pressure is increased, the pressure on the rubber cylinder is increased along with the increase of the pressure, the rubber cylinder is radially expanded to be in contact with the sleeve, and setting is completed.

A method of dual pressurized setting of a pressurizable set expandable packer comprising the steps of: in the process of going down the well, liquid in the inner central tube flows into the annular space A and the annular space B through the liquid guide holes in the inner central tube respectively, when the pressure of the liquid in the inner central tube is increased stably, the pressure of the liquid below the first pressurizing piston and the second pressurizing piston is increased accordingly, the first pressurizing piston and the second pressurizing piston are pushed to move upwards simultaneously to squeeze setting liquid, the setting liquid pressure is increased, the pressure on the rubber cylinder is increased accordingly, the rubber cylinder is radially expanded to be in contact with the sleeve, and setting is completed.

a method of anti-lift setting of a booster settable expandable packer comprising the steps of: in the process of descending the well, liquid in the inner central tube respectively flows into the annular space A and the annular space B through the liquid guide holes in the inner central tube, when the pressure of the liquid in the inner central tube is increased instantly, a large pressure difference is generated above and below the buffer slide block, the buffer slide block is subjected to upward thrust, the thrust enables the buffer slide block to move upwards to compress the buffer spring, the sectional area of the liquid guide channel B communicated with the liquid guide holes C is gradually reduced, the flow of the liquid flowing into the annular space B is reduced, the boosting piston moves upwards slightly, and in the process, the buffer spring absorbs part of energy, so that the instant setting liquid cannot reach the pressure required by setting; when the pressure increased instantly disappears, the pressure difference above and below the buffer slide block disappears, the buffer spring pushes the buffer slide block to return to the initial position, and the first pressurizing piston and the second pressurizing piston also reset downwards.

A method of using a pressure-settable expandable packer comprising the steps of:

In the process of going down the well, liquid inside the inner central tube flows into the annular space A and the annular space B through the liquid guide holes in the inner central tube respectively, when the pressure of the liquid inside the inner central tube is increased stably, the pressure of the liquid below the first pressurizing piston and the second pressurizing piston is increased accordingly, so that the first pressurizing piston and the second pressurizing piston are pushed to move upwards simultaneously to squeeze setting liquid, the setting liquid pressure is increased, the pressure applied to the rubber cylinder is increased accordingly, the rubber cylinder is radially expanded to be in contact with the sleeve, and setting is completed;

When the liquid pressure in the inner central tube is increased instantly in the process of descending, a larger pressure difference is generated above and below the buffer slide block, the buffer slide block is subjected to upward thrust, the buffer slide block moves upwards to compress the buffer spring, the cross section area of the liquid guide channel B communicated with the liquid guide hole C is gradually reduced, the liquid flow flowing into the annular space B is reduced, the boosting piston moves upwards for a small displacement, and the buffer spring absorbs part of energy in the process, so that the instant setting liquid cannot reach the pressure required by setting; when the pressure increased instantly disappears, the pressure difference above and below the buffer slide block disappears, the buffer spring pushes the buffer slide block to return to the initial position, and the first pressurizing piston and the second pressurizing piston also reset downwards.

the invention has the beneficial effects that:

1. The invention relates to a booster setting expansion packer, which comprises an upper connector, an upper baffle bowl, a rubber cylinder, a lower baffle bowl, an outer cylinder, a lower connector, an inner central pipe and a booster component, wherein the upper connector is connected with the upper baffle bowl; through "be provided with the setting liquid between outer center tube and the interior center tube, be provided with the drain hole on the interior center tube, be provided with pressure boost part"'s technical scheme in the annular space of urceolus and interior center tube, through setting up pressure boost part, when can making the pressurization, the internal pressure of setting liquid increases several times than the internal liquid pressure of interior center tube, the problem of current expanding packer unable effective setting under low throttle pressure differential has been avoided, can satisfy the setting demand under the low throttle pressure differential, reach better layering effect, prevent that fluid and pressure from disturbing each other between the layer, oil well production efficiency is improved.

2. According to the pressurizing component, by adopting the technical scheme that one end of the first pressurizing piston is a small-section end, the other end of the first pressurizing piston is a large-section end, the small-section end is in contact with the setting liquid, and the large-section end is in contact with the liquid injected into the inner central tube, when the pressure of the liquid in the inner central tube is increased, according to the principle that the pressure is unchanged and the pressure area is reduced from large to small, the pressure is increased along with the pressure, the first pressurizing piston can enable the pressure in the setting liquid to be obviously increased compared with the pressure of the liquid in the inner central tube through non-equal-area design, so that the pressure borne by the rubber sleeve is increased, and the expansion effect of the rubber sleeve is better than the direct action effect of.

3. According to the technical scheme, when the liquid pressure in the inner central tube is gradually increased, the liquid pressure below the second supercharging piston is increased along with the increase of the liquid pressure, and the second supercharging piston moves upwards under the action of gradually increased pressure so as to push the first supercharging piston to move upwards; meanwhile, the liquid pressure below the first pressurizing piston is increased, so that the first pressurizing piston is simultaneously acted by two thrusts, namely the thrust of the liquid below the first pressurizing piston and the thrust of the second pressurizing piston, according to the principle that the pressure is higher when the contact area is unchanged, the pressure is higher, the pressure in the seat sealing liquid is superposed and increased under the double pressurization of the first pressurizing piston and the second pressurizing piston, the pressure borne by the rubber sleeve in unit area is increased by multiple times, the rubber sleeve is more fully expanded, the packer is kept to have a better seat sealing effect under a lower throttling pressure difference, the expansion effect of the rubber sleeve is better than the direct action effect of the pressure of a pipe column, and effective layering is guaranteed.

4. According to the invention, through the buffer device below the second supercharging piston, the buffer device mainly comprises a buffer cylinder, a buffer spring is arranged in the buffer cylinder, the buffer spring is connected with a buffer slide block, and the buffer slide block can slide in the buffer cylinder; the technical scheme is that an annular space B' is formed among the second pressurizing piston, the buffer device, the inner central tube and the outer tube, when the pressure of liquid in the inner central tube is increased instantly, the buffer spring absorbs partial energy, and at the moment, the setting liquid cannot reach the pressure required by setting; when the pressure increased instantly disappears, the pressure difference between the upper part and the lower part of the buffer slide block disappears, the buffer spring pushes the buffer slide block to return to the initial position, and the first pressurizing piston and the second pressurizing piston also reset downwards, so that the occurrence of advanced setting caused by unstable liquid pressure in the downhole process of the packer is avoided.

Drawings

FIG. 1 is a schematic view of the overall structure of the present invention;

FIG. 2 is an enlarged view of FIG. 1 at A;

FIG. 3 is a state diagram at A of FIG. 1 when the pressure of the inner tube is momentarily increased in accordance with the present invention;

Fig. 4 is a schematic structural view of the second booster piston 10 of the present invention.

Illustration of the drawings:

1. An upper connector; 2. an upper retaining bowl; 3. a rubber cylinder; 4. an outer center tube; 5. an inner center tube; 51. an upper row of drainage holes; 52. a lower drainage hole; 6. a lower retaining bowl; 7. an outer cylinder; 71. a drainage channel A; 8. A first booster piston; 9. a retainer ring; 10. a second booster piston; 101. a piston rod; 11. a buffer device; 12. a lower connector; 13. an annular space A; 14. an annular space B; 111. a buffer cylinder; 112. a buffer spring; 113. A buffer slide block; 114. A drainage hole A; 115. a drainage hole B; 116. a drain hole C; 117. and a liquid guide channel B.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

As shown in fig. 1-2, the expandable packer capable of pressurized setting of the invention comprises an upper connector 1 of the packer, an upper retaining bowl 2 is screwed below the upper connector 1, the interior of the upper retaining bowl 2 is screwed with the upper end of a rubber cylinder 3, an outer central tube 4 is sleeved inside the rubber cylinder 3, and a plurality of pressure guide holes are uniformly distributed on the tube side of the outer central tube 4; the lower end of the rubber cylinder 3 is in threaded connection with a lower retaining bowl 6, the lower end of the lower retaining bowl 6 is in threaded connection with an outer cylinder 7, and the lower part of the outer cylinder 7 is in threaded connection with a lower connector 12; an inner central pipe 5 is screwed between the upper connector 1 and the lower connector 12, and a first pressurizing piston 8 is sleeved in an annular space between the outer barrel 7 and the inner central pipe 5 in a sliding manner; the pipe wall of the inner central pipe 5 is annularly provided with a plurality of upper rows of liquid guide holes 51 and a plurality of lower rows of liquid guide holes 52, and the inner part of the inner central pipe 5 is communicated with the space below the first pressurizing piston 8 through the upper rows of liquid guide holes 51;

Setting liquid is arranged between the inner central tube 5, the outer central tube 4, the lower retaining bowl 6, the outer tube 7 and the first pressurizing piston 8, and the setting liquid conducts pressure to the rubber tube 3 through the pressure guide hole of the outer central tube 4, so that the rubber tube 3 is pressed and opened. The rubber tube 3 can be expanded under a small pressure to perform a setting function, the expanding means under the small pressure of the rubber tube is a conventional means in the field, and the structure of the rubber tube 3 is not described again.

First pressure boost piston 8 is hollow structure, one end is little section end, the other end is big section end, little section end and setting liquid contact, the liquid contact of pouring into in big section end and the interior center tube 5, when the interior liquid pressure increase of center tube 5, according to pressure unchangeable, the pressurized area is by when diminishing greatly, the principle that pressure also can grow thereupon, first pressure boost piston 8 is through the design of unequal area, can make the interior liquid pressure of pressure than interior center tube 5 of setting liquid show the increase, thereby make the pressure increase that packing element 3 received, the expansion effect is better than the direct effect of tubular column pressure. When the design is carried out, the diameter of the first supercharging piston 8 can be adjusted to achieve a preset supercharging effect.

a check ring 9 is arranged below the first supercharging piston 8, the check ring 9 is sleeved between the outer cylinder 7 and the inner central pipe 5, a groove is formed in the outer cylinder 7, the check ring 9 can be clamped in the groove for positioning, and a through hole is formed in the check ring 9; an annular space A13 is formed between the first booster piston 8, the retainer ring 9, the inner center tube 5 and the outer cylinder 7.

As shown in fig. 4, the large diameter end of the first pressurizing piston 8 is connected with a second pressurizing piston 10, the second pressurizing piston 10 mainly comprises a piston and a piston rod 101 fixedly mounted on the piston, the piston can slide in a space formed by the outer cylinder 7 and the inner central tube 5, the piston rod 101 passes through a through hole of the retainer ring 9 and is fixedly connected with the first pressurizing piston 8, and a seal ring is fixedly mounted between the piston rod 101 and the through hole of the retainer ring 9.

the expandable packer capable of realizing pressurized setting further comprises a buffer device 11 arranged below the second pressurizing piston 10, specifically, as shown in fig. 2-3, the buffer device 11 mainly comprises a buffer cylinder 111, a buffer spring 112 is arranged in the buffer cylinder 111, the buffer spring 112 is connected with a buffer slide block 113, and the buffer slide block 113 can slide in the buffer cylinder 111; a limiting structure is arranged in the buffer cylinder 111 to limit the downward sliding position of the buffer slide block 113; an annular space B14 is formed between the second booster piston 10, the damper 11, the inner center tube 5, and the outer cylinder 7.

the top, the inner wall and the outer wall of the buffer cylinder 111 are respectively provided with a liquid guide hole A114, a liquid guide hole B115 and a liquid guide hole C116, a through liquid guide channel A71 is arranged in the outer cylinder 7, the liquid guide channel A71 is communicated with an annular space B14 below the second pressurizing piston 10, and a through liquid guide channel B117 is arranged in the buffer slide block 113; the liquid guide hole A114 connects the space where the buffer spring 112 is located with the annular space B14 below the second booster piston 10; the liquid guide hole B115 is matched with the liquid guide hole of the inner central tube 5, and the space at the lower part of the buffer cylinder 111 is communicated with the inside of the inner central tube 5; two openings of the liquid guide hole C116 are respectively matched with the liquid guide channel a71 and the liquid guide channel B117, and the liquid guide hole C116 can connect the liquid guide channel a71 with the liquid guide channel B117, so that the annular space B14 is connected with the space at the lower part of the buffer tube 111.

In the use process, when the pressure of the liquid in the inner central tube 5 is gradually increased, the pressure of the liquid below the second booster piston 10 is increased, and the second booster piston 10 moves upwards under the action of the gradually increased pressure, so that the first booster piston 8 is pushed to move upwards; at the same time, the pressure of the liquid below the first pressurizing piston 8 also increases, so that the first pressurizing piston 8 is simultaneously subjected to two thrusts, namely the thrust of the liquid below the first pressurizing piston and the thrust of the second pressurizing piston 10, because the pressure is higher when the contact area is unchanged, and the pressure is higher, so that the pressure in the setting liquid is superposed and increased under the double pressurization of the first pressurizing piston 8 and the second pressurizing piston 10.

Conventional expanding packer is because pressure is little under low throttle differential pressure, can't effectively sit and seal, can not reach the layering requirement, this application is through the dual function of the non-equal area design pressure boost of first pressure boost piston 8 and second pressure boost piston 10, promote first pressure boost piston 8 and remove under low differential pressure, make the pressure in the seat liquid be several times of the interior liquid pressure of center tube 5, thereby make 3 unit areas of packing element increase several times that receive, make the packing element inflation, thereby realize that the packer keeps better seat and seal the effect under lower throttle differential pressure, packing element inflation effect is better than the direct effect of tubular column pressure, thereby guarantee effectual layering.

conventional setting ware if the interior hydraulic pressure of interior center tube 5 increases in the twinkling of an eye in the process of transferring, packing element 3 can take place to set in advance under the tubular column pressure is direct, and this work load that not only can increase borehole operation, but also can influence the normal operating of oil well production to and the safety problem of well control.

In the invention, the buffer device 11 can effectively prevent the packer from setting in advance. When the liquid pressure inside the inner central tube 5 is stable, the initial position of the buffer sliding block 113 is designed when the cross section area of the liquid guide channel B117 communicated with the liquid guide hole C116 is the largest. When the pressure of the liquid in the inner central tube 5 is increased instantly, a larger pressure difference is generated above and below the buffer slide block 113, the buffer slide block 113 is subjected to upward thrust, the thrust makes the buffer slide block 113 move upwards to compress the buffer spring 112, the cross section area of the liquid guide channel B117 communicated with the liquid guide hole C116 is gradually reduced, as shown in FIG. 3, the flow rate of the liquid flowing into the annular space B14 is reduced, the boosting piston 10 moves upwards slightly, the buffer spring 112 absorbs part of energy in the process, and at the moment, the setting liquid cannot reach the pressure required by setting; when the pressure increased instantly disappears, the pressure difference between the upper part and the lower part of the buffer slide block 113 disappears, the buffer spring 112 pushes the buffer slide block 113 to return to the initial position, and the first pressurizing piston 8 and the second pressurizing piston 10 also reset downwards, so that the occurrence of advanced setting caused by unstable liquid pressure in the process of lowering the packer is avoided. When the liquid in the inner central tube 5 is normally and stably pressurized, the pressure difference between the upper part and the lower part of the buffer sliding block 113 is small or negligible due to the stable inflow of the liquid, and the cross-sectional area of the connection part of the liquid guide channel B117 and the liquid guide hole C116 is the largest, so the buffer device 11 only plays a buffer role when the pressure is instantly increased.

The working principle of the inflatable setting expansion packer of the application is as follows:

During downhole, fluid inside the inner base pipe 5 flows into annular space a13 and annular space B14 through the upper and lower rows of ports 51 and 52, when the liquid pressure in the inner central tube 5 is increased instantly, a large pressure difference is generated above and below the buffer slide block 113, the buffer slide block 113 is pushed upwards, the pushing force makes the buffer slide block 113 move upwards to compress the buffer spring 112, the cross-sectional area of the liquid guide channel B117 communicated with the liquid guide hole C116 becomes smaller gradually, as shown in fig. 3, the liquid flow flowing into the annular space B14 becomes smaller, the force increasing piston 10 makes a small displacement upwards, in the process, the buffer spring 112 absorbs the energy generated by the instantaneously increased pressure in the central pipe 5 in the part, and the first pressurizing piston 8 does not make the setting liquid reach the pressure required by setting under the action of the instantaneously increased pressure and the smaller thrust of the force increasing piston 10, so that the advance setting in the packer well-descending process can be effectively avoided; when the instantaneously increased pressure disappears, the pressure difference between the upper part and the lower part of the buffer slide block 113 disappears, the buffer spring 112 pushes the buffer slide block 113 to return to the initial position, and the first pressurizing piston 8 and the second pressurizing piston 10 also return downwards.

When the liquid pressure inside the inner central tube 5 is stably increased, the pressure of liquid below the first pressurizing piston 8 and the second pressurizing piston 10 is increased, so that the first pressurizing piston 8 and the second pressurizing piston 10 are pushed to move upwards to extrude setting liquid, the setting hydraulic pressure is increased, the pressure on the rubber sleeve 3 is increased, the rubber sleeve 3 is radially expanded to contact with a sleeve, the setting is completed, the packer can keep a good setting effect under a low throttling pressure difference, and underground layering is guaranteed.

The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art should be considered to be within the technical scope of the present invention, and the technical solutions and the inventive concepts thereof according to the present invention should be equivalent or changed within the scope of the present invention.