Packer and fracturing string thereof

Abstract

The utility model relates to the technical field of separate layer fracturing, and discloses a packer and a fracturing string thereof, which comprise a pipe body, a first opening is formed at the upper end of the pipe body, the first opening is used for being connected with an oil pipe, and a second opening is formed at the tail end of the pipe body to be communicated with a sleeve on the inner wall of a fracturing construction well. A pressure transmitting hole used for transmitting liquid pressure is formed in the side wall of the pipe body, the pressure transmitting hole is connected with a movable compression sleeve, the compression sleeve can be driven by the liquid pressure to move along the pipe body, the pipe body is provided with a rubber barrel adjacent to one side of the compression sleeve, a movable setting sliding sleeve is arranged in the pipe body, and an inner hole used for sealing a corresponding plugging ball is formed in the setting sliding sleeve. And the setting sliding sleeve moves to control opening and closing of the second opening and the pressure transmission hole. Liquid pressure injected by an oil pipe is used as a power source for setting, so that influence of an external oil and gas well is avoided, throttling is avoided during liquid transmission, and operation loss is approximate to zero.

Description

Technical Field

[0001] The utility model belongs to the field of staged fracturing technology, and specifically relates to a packer and its fracturing string. Background Art

[0002] Generally, during the well completion process, the packer is seated on the casing wall to isolate the annulus fluids above and below the packer, forming different pressure systems.

[0003] Currently, the commonly used staged fracturing mainly uses two types of packers: expansion type and compression type. Each fracturing layer is equipped with a throttling sandblasting sliding sleeve. By injecting a large volume of liquid into the tubing, a throttling effect is generated at the outlet of the throttling sandblasting sliding sleeve or the throttler, thereby forming an oil-casing pressure difference. Utilizing the oil difference inside and outside the tubing, the rubber barrel of the packer is compressed and expanded, and the expanded rubber barrel seals with the inner wall of the casing, realizing the setting of each packer connected to the upper part of the support string and closing each operation layer. For oil and gas wells with good formation absorbability and low construction pressure, the above-mentioned staged fracturing string can meet the construction requirements.

[0004] However, with the continuous deepening of the development of oil and gas wells, the number of ultra-deep wells and oil and gas wells with reservoirs below the bedrock is gradually increasing. For such oil and gas wells, the formation absorbability is generally poor, the formation fracture pressure is high, and before the formation fractures, a high injection volume cannot be achieved. The above-mentioned staged fracturing string cannot meet the construction requirements and will have the following problems:

[0005] Problem 1: The setting power source of the packer depends on the throttling pressure difference formed by the constriction of the sandblasting holes on the sandblasting sliding sleeve, and the formation of the throttling pressure difference depends on the fluid displacement. For oil and gas wells with high formation fracture pressure and poor absorption performance, at the initial stage of construction, that is, before the formation fractures, the injection volume is extremely low or even zero. Under such conditions, it is impossible to establish an oil-casing pressure difference and form a power source to maintain the setting of the packer. The setting conditions of the packer cannot be met, resulting in the failure of layer isolation;

[0006] Problem 2: When the geological conditions can meet the setting conditions of the packer, once the oil-casing pressure difference is established, all packers are set simultaneously. When constructing the following layers, it is very difficult to determine whether the lower packer is in a good set state, and thus it is impossible to judge the construction quality of each layer;

[0007] Problem 3: For oil and gas wells with high formation fracture pressure, the injection pressure exceeds the compressive capacity of the tubing. Therefore, a balancing pressure needs to be applied to the oil-casing annulus to support the ultra-high pressure injection inside the tubing. Referring to the balancing pressure injected into the oil-casing annulus being blocked by the packer 3 and unable to reach the top of the lower construction layer, the pressure-bearing capacity of the tubing connecting the layers exceeds the pressure-bearing limit and fractures, unable to meet the requirements of high-pressure construction.

[0008] Problem 4: For a fracturing operation well, once the formation fractures under high pressure, it is necessary to inject fracturing fluid into the formation at a large displacement. Limited by the throttling holes of the sandblasting sliding sleeve, increasing the construction displacement will pose risks of overpressure and sand plugging.

[0009] In view of this, the present utility model is specifically proposed. Summary of the Utility Model

[0010] To solve the above technical problems, the basic concept of the technical solution adopted by the present utility model is as follows:

[0011] A device includes a pipe body. A first opening is formed at the upper end of the pipe body for connecting with an oil pipe. A second opening is formed at the end of the pipe body to communicate with a casing on the inner wall of the fracturing operation well. A pressure transmission hole for transmitting liquid pressure is formed on the side wall of the pipe body. The pressure transmission hole is connected with a movable compression sleeve. The compression sleeve can be driven by liquid pressure to move along the pipe body. A rubber cylinder is arranged adjacent to the compression sleeve on one side of the pipe body.

[0012] A movable setting slip is arranged inside the pipe body. An inner hole for hermetically sealing a corresponding plugging ball is formed inside the setting slip. The setting slip moves to control the opening and closing of the second opening and the pressure transmission hole.

[0013] The setting slip closes the second opening and opens the pressure transmission hole, so that the liquid pressure injected into the pipe body from the first opening enters through the pressure transmission hole, causing the compression sleeve to move along the pipe body and compress the rubber cylinder for setting.

[0014] As a preferred embodiment of the present utility model, the pipe body is provided with a one-way mechanism and is connected with the compression sleeve through the one-way mechanism. The one-way mechanism enables the compression sleeve to move only towards the side close to the rubber cylinder to maintain setting.

[0015] As a preferred embodiment of the present utility model, the one-way mechanism includes a self-destructing part made of a soluble material. The self-destructing part dissolves and self-destructs within a limited time in the well, releasing the positioning of the compression sleeve by the one-way mechanism, and enabling the rubber cylinder to recover by its own elasticity to release setting.

[0016] As a preferred embodiment of the present utility model, the one-way mechanism includes a locking sleeve arranged in the inner sandwich layer of the compression sleeve. The locking sleeve is a one-way open tooth ring and moves unidirectionally with the pipe body through a one-way thread. The self-destructing part includes a locking sleeve pressing ring. The locking sleeve pressing ring is arranged between the compression sleeve and the locking sleeve. The locking sleeve pressing ring can rotate relative to the locking sleeve and is fixed to the compression sleeve to support the positioning of the compression sleeve.

[0017] As a preferred embodiment of the present utility model, setting shear pins are arranged on the pipe body. The setting shear pins fix the setting slip on one side of the pressure transmission hole to make the setting slip close the pressure transmission hole.

[0018] As a preferred embodiment of the present utility model, the pipe body includes a first packer. The first packer is located at the tail of the fracturing string. A limit ring is provided at the tail of the first packer. A limiting surface is formed at the upper end of the limit ring. The limiting surface can be abutted by the setting slip sleeve and sealed with the setting slip sleeve to close the second opening. The limit ring is fixed to the first packer by limit shear pins, and the shear value of the limit shear pins is greater than the shear value of the setting shear pins.

[0019] As a preferred embodiment of the present utility model, the pipe body includes a second packer. A sandblaster is provided downstream of the second packer. Sandblasting holes are formed in the side wall of the sandblaster.

[0020] A slidable sandblasting slip sleeve is provided inside the sandblaster. A sandblasting shear pin for fixing the sandblasting slip sleeve is fixedly arranged between the sandblasting slip sleeve and the sandblaster. The sandblasting slip sleeve is fixed to one side of the sandblasting hole by the sandblasting shear pin, so that the sandblasting slip sleeve closes the sandblasting hole. The shear value of the sandblasting shear pin is higher than the shear value of the setting slip sleeve of the upper packer.

[0021] As a preferred embodiment of the present utility model, the sandblasting holes are arranged in a circumferential multi-hole pattern, and the cross-sectional sum of the sandblasting holes is larger than the cross-sectional area of the inner diameter of the tubing.

[0022] As a preferred embodiment of the present utility model, a first sealing port is formed at the upper part of the sandblasting slip sleeve. The first sealing port is used to receive the setting slip sleeve that has fallen off from the upstream packer and is sealingly connected to the setting slip sleeve. A second sealing port is formed at the top of the pipe body. The second sealing port is used to receive the sandblasting slip sleeve that has fallen off from the upstream sandblaster and is sealingly connected to the sandblasting slip sleeve.

[0023] A fracturing string includes the packer described in any one of the above.

[0024] The present utility model has the following beneficial effects compared with the prior art:

[0025] 1. Since the liquid pressure injected through the tubing is used as the power source for setting, it is not affected by the external oil and gas wells, and can be applied to oil and gas wells with high formation fracture pressure and poor absorption performance. Moreover, there is no throttling in liquid transmission, and the operation loss is approximately zero.

[0026] 2. Whether each stage of packer is set is controlled by the corresponding slip sleeve respectively. Therefore, it can be set or released step by step according to different formation requirements, which is convenient for determining whether the lower packer is in a good set state through the annulus pressure data and judging the construction quality of each layer.

[0027] 3. Since step-by-step setting can be achieved, balanced pressure can be injected into the annulus step by step to ensure that the balancing liquid can reach each construction layer and improve the pressure-bearing capacity of the tubing.

[0028] 4. Since there is no need to generate a throttling pressure difference in the sandblasting holes, the sandblasting holes only retain the basic function of sandblasting. The total cross-sectional area of each sandblasting hole can be enlarged, the risk of overpressure and sand blockage can be reduced, and the flow rate of sandblasting can be decreased. The erosion power is small, and the impact on the casing can be reduced.

[0029] 5. Self-destructive materials are used for delayed self-unsealing, eliminating the need for an additional power source, simplifying the product structure, and realizing the subsequent full-bore logging process.

[0030] 6. Since each sliding sleeve is gradually fixed by each shear pin, there is no risk of incorrect setting position. The sliding sleeves fall layer by layer, realizing the interlock of the structural design and reducing unexpected situations.

[0031] The following further describes in detail the specific implementation manners of the present utility model with reference to the accompanying drawings. Description of the Drawings

[0032] In the drawings:

[0033] Figure 1 is a schematic structural view of the first packer of the present invention;

[0034] Figure 2 is a schematic structural view of the second packer of the present invention;

[0035] Figure 3 is a schematic structural view of the sandblaster of the present invention;

[0036] Figure 4 is a schematic view of the second state of the sandblaster of the present invention;

[0037] Figure 5 is a schematic view of the third state of the sandblaster of the present invention;

[0038] Figure 6 is a schematic structural view of the fracturing string of the present invention;

[0039] Figure 7 is a schematic view of the construction of operation layer 1 of the present invention;

[0040] Figure 8 is a schematic view of the first step of the construction of operation layer 2 of the present invention;

[0041] Figure 9 is a schematic view of the second step of the construction of operation layer 2 of the present invention;

[0042] Figure 10 is a schematic view of the construction of operation layer 3 of the present invention;

[0043] Figure 11 is a schematic view of the end of the downhole construction of the present invention.

[0044] 1. Body; 11. Pressure transmission hole; 12. Setting shear pin; 13. Second sealing port; 2. Compression sleeve; 21. Locking sleeve; 22. Locking sleeve thrust ring; 23. Locking sleeve compression ring; 3. Rubber cylinder; 4. Setting sliding sleeve; 5. First packer; 51. Limiting ring; 52. Limiting shear pin; 6. Second packer; 7. Sandblaster; 71. Sandblasting hole; 72. Sandblasting sliding sleeve; 721. First sealing port; 73. Sandblasting shear pin; 8. Hydraulic anchor claw

[0045] A. No. 1 packer; B. No. 2 packer; C. No. 3 packer, D. No. 1 sandblaster; E. No. 2 sandblaster; F. No. 1 plugging ball; G. No. 2 plugging ball; H. No. 3 plugging ball Specific implementation mode

[0046] To make the objectives, technical solutions and advantages of the embodiments of the present utility model clearer, the following will clearly and completely describe the technical solutions in the embodiments in conjunction with the accompanying drawings in the embodiments of the present utility model. The following embodiments are used to illustrate the present utility model

[0047] Embodiment 1

[0048] As Figure 1 and Figure 2 shown, the packer of the present invention includes a body 1. A first opening is formed at the upper end of the body 1, and the first opening is used to connect with the oil pipe. The oil pipe injects materials into the first opening according to the fracturing process to fracture each working layer. The second opening is located at the end of the body 1 and is used to communicate with the casing on the inner wall of the fracturing construction well. In order to set the packer, a setting mechanism is provided on the body 1

[0049] The setting mechanism includes a pressure transmission hole 11. The pressure transmission hole 11 is arranged on the side wall of the body 1. The pressure transmission hole 11 is connected with a movable compression sleeve 2. A rubber cylinder 3 is arranged adjacent to the compression sleeve 2 on the body 1. The pressure transmission hole 11 transmits liquid pressure to move the compression sleeve 2 along the body 1 to compress the rubber cylinder 3, so that the rubber cylinder 3 expands radially and closes the oil-casing annulus to achieve setting

[0050] In order to separately control the setting of each stage, a movable setting sliding sleeve 4 is arranged in the body 1. An inner hole for sealing the corresponding plugging ball is formed in the setting sliding sleeve 4. The setting sliding sleeve 4 moves to control the opening and closing of the second opening and the pressure transmission hole 11. The setting sliding sleeve 4 closes the second opening and opens the pressure transmission hole 11, so that the liquid pressure injected into the body 1 from the first opening enters through the pressure transmission hole 11 to compress the rubber cylinder 3 and achieve setting

[0051] Thus, whether each stage of the packer is set is respectively controlled by the corresponding setting sliding sleeve 4. Therefore, setting or releasing can be carried out step by step according to different formation requirements, and low-displacement step-by-step setting control can be achieved

[0052] In order to maintain the setting after setting and prevent it from being affected by the setting slip sleeve 4, the pipe body 1 is provided with a one-way mechanism, which is connected to the compression sleeve 2 through the one-way mechanism. The one-way mechanism enables the compression sleeve 2 to move only towards the side close to the rubber cylinder 3 to maintain the setting.

[0053] Specifically, the one-way mechanism includes a locking sleeve 21 arranged in the inner sandwich layer of the compression sleeve 2. The locking sleeve 21 is a one-way open-tooth ring and moves unidirectionally with the pipe body 1 through a one-way thread. A locking sleeve thrust ring 22 is arranged on the side of the locking sleeve 21 close to the pressure transmission hole 11. The locking sleeve thrust ring 22 is sleeved outside the pipe body 1 to receive the liquid pressure transmitted by the pressure transmission hole 11. A locking sleeve pressure ring 23 is also arranged between the compression sleeve 2 and the locking sleeve 21. The locking sleeve pressure ring 23 can rotate relative to the locking sleeve 21 and is fixed to the compression sleeve 2 to support the positioning of the compression sleeve 2.

[0054] To release the setting of the packer, the one-way mechanism includes a self-destruction part made of a soluble material. The self-destruction part dissolves and self-destructs within a limited time in the well, canceling the positioning of the one-way mechanism on the compression sleeve 2, so that the rubber cylinder 3 relies on its own elasticity to recover and the setting is released. Specifically, the above-mentioned locking sleeve pressure ring 23 is the self-destruction part, and the soluble material is an existing material, which will not be elaborated in this embodiment.

[0055] Moreover, a setting shear pin 12 is arranged on the pipe body 1. The setting shear pin 12 fixes the setting slip sleeve 4 on one side of the pressure transmission hole 11, so that the setting slip sleeve 4 closes the pressure transmission hole 11. The tubing is pressurized to push the setting slip sleeve 4 to cut off the setting shear pin 12 and move downward, opening the pressure transmission hole 11 for setting.

[0056] The packer needs to be provided with different structures according to its position in the fracturing string.

[0057] Therefore, as Figure 1 shown, the pipe body 1 includes a first packer 5. The first packer 5 is located at the tail of the fracturing string. A limit ring 51 is arranged at the tail of the first packer 5. A limiting surface is formed at the upper end of the limit ring 51. The limiting surface can be abutted by the setting slip sleeve 4 and is sealed with the setting slip sleeve 4 to close the second opening. The limit ring 51 is fixed to the first packer 5 through a limit shear pin 52. The shear value of the limit shear pin 52 is greater than the shear value of the setting shear pin 12, so as to control the position of the setting slip sleeve 4 by pressure, enabling the setting slip sleeve 4 to have three states:

[0058] In the initial state, the setting slip sleeve 4 is fixed by the setting shear pin 12. The setting slip sleeve 4 seals the pressure transmission hole 11. The locking sleeve thrust ring 22 is in the initial position, and the rubber cylinder 3 is not squeezed; in the second state, the setting slip sleeve 4 is located at the limit ring 51 and is fixed by the sealing shear pin. The setting slip sleeve 4 and the plugging ball close the second opening at the lower end of the pipe body 1, enabling the liquid pressure to enter from the pressure transmission hole 11 and squeezing the rubber cylinder 3 to achieve setting; in the third state, the setting slip sleeve 4 disengages from the second opening, well water flows into the pressure transmission hole 11, and after the self-locking mechanism is self-destroyed, the setting is released.

[0059] As shown Figure 2 in FIG. 1, the pipe body 1 includes a second packer 6. Downstream of the second packer 6 is a sandblasting tool 7. Sandblasting holes 71 are formed in the side wall of the sandblasting tool 7. The sandblasting holes 71 are arranged in a circumferential multi-hole pattern. The cross-sectional sum of each through hole is larger than the inner diameter cross-section of the tubing, so as to reduce the flow rate, reduce the impact on the casing, and protect the casing. Generally, three sandblasting holes 71 are provided.

[0060] As shown Figure 3 in FIG. 2, a slidable sandblasting sleeve 72 is provided in the sandblasting tool 7. A sandblasting shear pin 73 for fixing the sandblasting sleeve 72 is fixedly arranged between the sandblasting sleeve 72 and the sandblasting tool 7. The sandblasting sleeve 72 is fixed on one side of the sandblasting hole 71 through the sandblasting shear pin 73, so that the sandblasting sleeve 72 closes the sandblasting hole 71. A first sealing port 721 is formed on the upper part of the sandblasting sleeve 72. The first sealing port 721 is used to receive the setting slip sleeve 4 that has fallen off the packer located upstream and is sealingly connected to the setting slip sleeve 4. The shear value of the sandblasting shear pin 73 is higher than the shear value of the setting slip sleeve 4 of the upper packer and meets the pressure value required for the packer to set. And a second sealing port 13 is formed at the top of the pipe body 1. The second sealing port 13 is used to receive the sandblasting sleeve 72 that has fallen off the sandblasting tool 7 located upstream and is sealingly connected to the sandblasting sleeve 72.

[0061] Thus, the second packer 6 has four states:

[0062] In the initial state, the setting slip sleeve 4 is fixed by the setting shear pin 12. The setting slip sleeve 4 seals the pressure transmission hole 11. The lock sleeve thrust ring 22 is in the initial position, and the rubber cylinder 3 is not extruded; the sandblasting sleeve 72 is fixed by the sandblasting shear pin 73 to close the sandblasting hole 71; in the second state, as shown Figure 4 in FIG. 3, the setting slip sleeve 4 is located at the sandblasting sleeve 72 and is fixed by the setting shear pin 12. The setting slip sleeve 4 and the plugging ball close the lower opening of the pipe body 1, so that the liquid pressure enters from the pressure transmission hole 11 to extrude the rubber cylinder 3 to achieve setting; in the third state, as shown Figure 5 in FIG. 4, the setting slip sleeve 4 and the sandblasting sleeve 72 are located at the second sealing port 13 of the lower packer, so that the proppant (sand) can be ejected from the sandblasting hole 71; in the fourth state, the setting slip sleeve 4 and the sandblasting sleeve 72 are separated, the well water flows into the pressure transmission hole 11, and the self-locking mechanism self-destructs to release the setting.

[0063] Moreover, the above-mentioned limit ring 51, setting slip sleeve 4, and sandblasting sleeve 72 are all made of soluble self-destructive materials. After the fracturing construction is completed, they dissolve and self-destruct, leaving no residue in the pipe string, achieving full bore and supporting subsequent operations.

[0064] Embodiment 2

[0065] The present invention also discloses a fracturing string, as shown Figure 6As shown in the figure, it includes the above-mentioned packer. A number of second packers 6 are provided according to the construction conditions. The first packer 5 is arranged at the tail of the fracturing string, and the sandblaster 7 is arranged between adjacent packers for fracturing operations.

[0066] The inner holes of the setting slips 4 of each packer are divided into different apertures according to a step difference and gradually decrease from top to bottom. Taking three packers as an example, the lowermost No. 1 packer A is the first packer 5, and the upper No. 2 packer B and No. 3 packer C adopt the second packer 6. The aperture of the setting slip 4 on the No. 2 packer B can pass the plugging ball matched with the setting slip 4 on the No. 1 packer A; the aperture of the setting slip 4 on the No. 3 packer C can pass the plugging ball matched with the setting slip 4 on the No. 2 packer B; and so on.

[0067] Taking three packers as an example again, between the No. 1 packer A and the No. 2 packer B is the No. 1 sandblaster D, between the No. 2 packer B and the No. 3 packer is the No. 2 sandblaster E, the plugging ball corresponding to the No. 1 packer A is the No. 1 plugging ball F; the plugging ball corresponding to the No. 2 packer B is the No. 1 plugging ball G, and the plugging ball corresponding to the No. 3 packer C is the No. 1 plugging ball H. The construction process is as follows:

[0068] Operation layer 1 construction

[0069] As Figure 7 shown in the figure, the No. 1 plugging ball F is put into the well to plug the setting slip 4 on the No. 1 packer A. The tubing is pressurized to knock off the setting slip 4 and form a seal with the lower limit ring 51. At this time, the pressure injected by the tubing enters the setting mechanism of the No. 1 packer A through the pressure transmission hole 11, compresses the rubber cylinder 3, achieves the setting purpose, and realizes self-locking;

[0070] The tubing continues to boost pressure to knock off the limit ring 51 and the setting slip 4, and a fracturing injection channel is established between operation layer 1 and the lower part of the No. 1 packer A. At this time, the No. 2 packer B and the No. 3 packer C are controlled by the setting slip 4 and are in an unoperated state. The balancing pressure applied by the casing can directly act on the upper part of the No. 1 packer A, which can monitor whether the No. 1 packer A is well sealed and protect the tubing from bearing high-pressure operations.

[0071] Operation layer 2 construction

[0072] As Figure 8 and Figure 9 shown in the figure, the No. 2 plugging ball G is put into the well to plug the setting slip 4 on the No. 2 packer B. The tubing is pressurized to knock off the setting slip 4 and form a seal with the sandblasting slip 72 on the No. 1 sandblaster D. At this time, the pressure injected by the tubing enters the setting mechanism of the No. 2 packer B through the pressure transmission hole 11. After the rubber cylinder 3 is compressed to achieve the setting purpose and self-locking is realized, the tubing continues to boost pressure to knock off the sandblasting slip 72, and a fracturing injection channel is established between the lower part of the No. 2 packer B and operation layer 2.

[0073] At this time, the No. 1 packer A is still in the working state. The dropped sandblasting sliding sleeve 72, the packer setting sliding sleeve 4 and the No. 2 plugging ball G fall together and sit on the second sealing port 13 at the top of the No. 1 packer A, closing the operation layer 1 that has completed the construction, so that the No. 1 packer A and the No. 2 packer B completely seal the annulus outside the operation layer 2, forming an independent operation channel.

[0074] At this time, the No. 3 packer C is in the non-working state under the control of the setting sliding sleeve 4. The balancing pressure applied by the casing can directly act on the upper part of the No. 2 packer B, which can monitor whether the No. 2 packer B is well sealed and protect the tubing from bearing high-pressure operations.

[0075] Construction of operation layer 3

[0076] Such as Figure 10 shown, the No. 3 plugging ball H is put into the wellhead. The construction steps and principles are the same as those of the operation layer 2, and will not be elaborated in this embodiment.

[0077] Such as Figure 11 shown, the downhole construction process is all completed, and the drill-out operation is carried out

[0078] After the fracturing construction is completed, within the preset time, the plugging balls put into the wellhead, the setting sliding sleeve 4 on the No. 2 packer B and the No. 3 packer C, the No. 1 packer A, the No. 2 packer B, the setting sliding sleeve 4 on the No. 3 packer C, and the self-locking mechanism self-destruct and dissolve, a full-bore is formed in the work string, and the packers are released by themselves; the oil-casing pressure difference disappears, the hydraulic anchor claws 8 return to their original positions by themselves, the pipe string anchoring is released, and the pipe string is lifted to take out the tool string from the well.

[0079] It can be understood that the present utility model is described through some embodiments. Those skilled in the art know that without departing from the spirit and scope of the present utility model, various changes or equivalent replacements can be made to these features and embodiments. In addition, under the teaching of the present utility model, these features and embodiments can be modified to adapt to specific situations and materials without departing from the spirit and scope of the present utility model. Therefore, the present utility model is not limited by the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application belong to the scope protected by the present utility model.

Claims

1. A packer, comprising a pipe body (1), wherein the upper end of the pipe body (1) is formed with a first opening for connecting with an oil pipe, and the lower end of the pipe body (1) is formed with a second opening for communicating with a casing on the inner wall of a fracturing well, wherein: A pressure transmission hole (11) for transmitting liquid pressure is formed on the side wall of the tube body (1), and a movable compression sleeve (2) is connected to the pressure transmission hole (11). The compression sleeve (2) can be driven by the liquid pressure to move along the tube body (1), and a rubber sleeve (3) is arranged on the tube body (1) adjacent to the compression sleeve (2); A movable sealing sleeve (4) is arranged in the pipe body (1), and an inner hole for sealing a corresponding sealing ball is formed in the sealing sleeve (4); the sealing sleeve (4) moves to control the opening and closing of the second opening and the pressure transmission hole (11); The sealing sleeve (4) closes the second opening and opens the pressure transmission hole (11), allowing the liquid pressure injected into the pipe body (1) from the first opening to enter from the pressure transmission hole (11), causing the compression sleeve (2) to move along the pipe body (1) and compress the rubber sleeve (3), thereby performing sealing.

2. The packer according to claim 1, characterized in that: The tube body (1) is provided with a one-way mechanism and is connected to the compression sleeve (2) via the one-way mechanism. The one-way mechanism enables the compression sleeve (2) to move only toward the side close to the rubber cylinder (3) to maintain the sealing.

3. The packer according to claim 2, characterized in that: The one-way mechanism comprises a self-destructing part made of a soluble material, which dissolves and self-destructs in a limited time in the well, thereby releasing the one-way mechanism from positioning the compression sleeve (2), and allowing the rubber cylinder (3) to recover by its own elasticity, thereby releasing the seal.

4. The packer according to claim 3, characterized in that: The one-way mechanism comprises a locking sleeve (21) arranged in an inner interlayer of the compression sleeve (2); the locking sleeve (21) is a one-way open toothed ring, and moves in one direction with the tube body (1) via a one-way thread; the self-destructing component comprises a locking sleeve pressure ring (23), the locking sleeve pressure ring (23) is arranged between the compression sleeve (2) and the locking sleeve (21), the locking sleeve pressure ring (23) can rotate relative to the locking sleeve, and is fixed to the compression sleeve (2) to support the compression sleeve (2) in position.

5. The packer according to claim 1, characterized in that: The pipe body (1) is provided with a setting shear pin (12), and the setting shear pin (12) fixes the setting sleeve (4) to one side of the pressure transmission hole (11), so that the setting sleeve (4) seals the pressure transmission hole (11).

6. The packer according to claim 5, characterized in that: The pipe body (1) comprises a first packer (5), the first packer (5) is located at the tail of the fracturing pipe string, a limiting ring (51) is arranged at the tail of the first packer (5), a limiting surface is formed at the upper end of the limiting ring (51), and the limiting surface can be abutted by the setting sleeve (4) and sealed with the setting sleeve (4) to close the second opening; the limiting ring (51) is fixed to the first packer (5) by limiting shear pins (52), and the shear value of the limiting shear pins (52) is greater than the shear value of the setting shear pins (12).

7. The packer according to claim 1, characterized in that: The pipe body (1) comprises a second packer (6), a sandblaster (7) is provided downstream of the second packer (6), and a sandblasting hole (71) is provided on the side wall of the sandblaster (7); A slidable sandblasting sleeve (72) is provided in the sandblaster (7); a sandblasting shearing pin (73) for fixing the sandblasting sleeve (72) is fixedly provided between the sandblasting sleeve (72) and the sandblaster (7); the sandblasting sleeve (72) is fixed to one side of the sandblasting hole (71) by the sandblasting shearing pin (73), so that the sandblasting sleeve (72) closes the sandblasting hole (71); and the shear value of the sandblasting shearing pin (73) is higher than the shear value of the upper packer setting sleeve (4).

8. The packer according to claim 7, characterized in that: The sandblasting holes (71) are arranged at multiple circumferential positions, and the cross-section of each sandblasting hole (71) is greater than the cross-section of the inner diameter of the oil pipe.

9. The packer according to claim 7, characterized in that: A first sealing opening (721) is formed on the upper portion of the sandblasting sleeve (72), and the first sealing opening (721) is used to receive the setting sleeve (4) that has fallen off from the upstream packer, and is sealedly connected to the setting sleeve (4); a second sealing opening (13) is formed on the top of the pipe body (1), and the second sealing opening (13) is used to receive the sandblasting sleeve (72) that has fallen off from the upstream sandblaster, and is sealedly connected to the sandblasting sleeve (72).

10. A fracturing string, characterized in that: Comprising the packer as described in any one of claims 1-9.

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