High temperature 250 degree expandable fracturing packer

Abstract

The present application relates to the technical fields of packer, and proposes a high-temperature-resistant 250-degree expansion type fracturing packer, which comprises a center pipe, a locking mechanism, a sealing mechanism and an anchoring mechanism arranged on the center pipe in sequence, and the sealing mechanism comprises a first sealing cylinder, a second sealing cylinder and a third sealing cylinder, the second sealing cylinder comprises a plurality of first sealing blocks and a plurality of second sealing blocks, which are uniformly distributed around the center pipe in the circumferential direction and can slide along the center pipe in the radial direction, the second sealing blocks are arranged at intervals from the first sealing blocks, and each second sealing block is sealed with two first sealing blocks adjacent thereto; a reset spring is arranged to provide elastic force for moving the first sealing blocks and the second sealing blocks close to the center pipe; the first sealing cylinder and the second sealing cylinder can be compressed under the action of the locking mechanism, and the first sealing blocks and the second sealing blocks can slide outward under the action of the locking mechanism. Through the above technical scheme, the problem of poor high-temperature resistance of the packer in the prior art and the difficulty in maintaining good sealing performance for a long time under high temperature are solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field, specifically, relates to high-temperature-resistant 250-degree expansion type fracturing packer. BACKGROUND

[0002] In the field of oil and gas field development, packer is an important component for implementing downhole injection and production processes such as separate layer oil production, separate layer water injection, separate layer fracturing, acidification or mechanical plugging, and the elastic sealing cylinder is the core component of the packer, which will directly affect the working quality of the packer. In the development of oil and gas fields, the depth of oil and gas wells is getting deeper and deeper, and as the depth of oil and gas wells increases, the temperature and pressure of the mining environment become greater, so higher requirements are put forward for the rubber cylinder of the packer to adapt to the above harsh working conditions. However, the existing sealing cylinder is generally made of rubber cylinder, which is deformed by extrusion at both ends to form a seal for the outer sleeve and inner core (shaft or pipe) of the oil and gas well, but it is easy to be damaged in the high temperature environment of the downhole, affecting the sealing effect and difficult to maintain good sealing between the attempts. SUMMARY

[0003] The present application provides a high-temperature-resistant 250-degree expansion type fracturing packer, which solves the problems in the prior art.

[0004] The technical scheme of the present application is as follows:

[0005] The high-temperature-resistant 250-degree expansion type fracturing packer comprises a center pipe, a locking mechanism, a sealing mechanism and an anchoring mechanism arranged in sequence on the center pipe, the sealing mechanism is sealed under the action of the locking mechanism, and the sealing mechanism comprises:

[0006] A first sealing cylinder, a second sealing cylinder and a third sealing cylinder are arranged in sequence on the center pipe, the first sealing cylinder and the second sealing cylinder, and the second sealing cylinder and the third sealing cylinder are provided with a pressing block therebetween, and the second sealing cylinder comprises:

[0007] A first sealing block, the first sealing block is a plurality of, uniformly distributed around the center pipe in the circumferential direction, and can slide radially along the center pipe;

[0008] A second sealing block, the second sealing block is a plurality of, uniformly distributed around the center pipe in the circumferential direction, and can slide radially along the center pipe, the second sealing block is arranged at intervals with the first sealing block, and the second sealing block is sealed with the two first sealing blocks adjacent thereto;

[0009] A reset spring for providing elastic force to make the first sealing block and the second sealing block close to the center pipe;

[0010] The first sealing cylinder and the second sealing cylinder are compressed by the locking mechanism, and the first sealing block and the second sealing block are slid outward by the locking mechanism.

[0011] Further, a first pressing block is arranged between the first sealing cylinder and the second sealing cylinder, the first pressing block is provided with a first inclined surface, a plurality of first partition plates are arranged on the first inclined surface in a circumferential direction, and the first sealing block is arranged between two adjacent first partition plates.

[0012] A second pressing block is arranged between the second sealing cylinder and the third sealing cylinder, the second pressing block is provided with a second inclined surface, a plurality of second partition plates are arranged on the second inclined surface in a circumferential direction, and the second sealing block is arranged between two adjacent second partition plates.

[0013] The first inclined surface and the second inclined surface oppositely form a space with an outer side larger than an inner side, and the first partition plates and the second partition plates are arranged in a spaced manner.

[0014] Further, the locking mechanism comprises:

[0015] A screw rod is rotationally arranged on the central pipe.

[0016] A nut is arranged on the screw rod and slides along a generatrix direction of the central pipe.

[0017] A first push block slides along the generatrix direction of the central pipe under the action of the nut and is in contact with the first sealing cylinder.

[0018] Further, the locking mechanism further comprises:

[0019] An outer sleeve is arranged on the screw rod, and an inner part of the outer sleeve is provided with a track for guiding the nut.

[0020] A friction block is arranged on the outer sleeve by an elastic member and can slide along a radial direction of the outer sleeve.

[0021] Further, an end surface of the friction block for contacting the pipe string is provided with a first friction pattern along a length direction of the pipe string.

[0022] Further, the anchoring mechanism comprises:

[0023] A fixed disc is provided with a plurality of first tracks in a radial direction.

[0024] A driving disc is provided with a plurality of second tracks.

[0025] A plurality of anchor blocks slide relative to the first tracks and the second tracks, and the anchor blocks slide along the first tracks under the action of the driving disc.

[0026] A driving mechanism is arranged to drive the driving disc to rotate.

[0027] Further, the driving mechanism comprises:

[0028] A cylinder, which is provided with a first cavity and a second cavity,

[0029] A piston, which is slidingly arranged in the first cavity and divides the first cavity into a first chamber and a second chamber;

[0030] A second push block, which is fixedly connected with the piston and in contact with the third sealing cylinder;

[0031] A partition plate and a sealing plate, the partition plate is fixedly arranged in the second cavity, the sealing plate is rotatably arranged in the second cavity, the partition plate and the sealing plate divide the second cavity into a third chamber and a fourth chamber, the third chamber and the fourth chamber are in communication and filled with oil, and the sealing plate is coaxially arranged with the driving disc;

[0032] An unsealing spring, which is arranged in the second cavity and provides an elastic force for moving the piston to a direction in which the volume of the first chamber is reduced.

[0033] Further, a positioning sleeve is fixedly connected with the fixed disc.

[0034] Further, the end surface of the anchor block for contacting the pipe column is provided with a second frictional pattern which is perpendicular to the length direction of the pipe column.

[0035] The working principle and beneficial effects of the present application are as follows:

[0036] In the application, the anchoring mechanism is used to be fixed in the pipe string when the packer is set, the sealing mechanism is driven by the locking mechanism to realize the sealing of the pipe string, the setting is completed, the sealing mechanism is designed with three layers of sealing cylinders, the first sealing cylinder and the third sealing cylinder are made of heat-resistant rubber, and the sealing between the pipe string is realized by compression through the action of the locking mechanism during setting; the second sealing cylinder is composed of a plurality of first sealing blocks and a plurality of second sealing blocks, the first sealing block and the second sealing block are slid outward to seal with the pipe string under the action of the locking mechanism during setting, the first sealing block and the second sealing block are retracted inward at the same time during unsetting, and the first sealing block and the second sealing block always maintain sealing between them, which guarantees the sealing effect. Through the design of three layers of sealing structure, the sealing effect required during setting can be effectively achieved, and the heat insulation effect of three layers of sealing is better, which can still guarantee good sealing under high temperature. The second sealing cylinder in the middle changes the sealing mode of commonly used rubber compression, adopts sealing block sliding to seal, avoids the influence of rubber material aging on sealing effect caused by high temperature, and effectively improves the high temperature resistance of the packer, improves the sealing effect of the packer under high temperature, and increases the service life. BRIEF DESCRIPTION OF DRAWINGS

[0037] The application will be further described in detail below in combination with the drawings and specific embodiments.

[0038] Figure 1 It is a structure diagram of the packer;

[0039] Figure 2 It is a structure diagram of the first pressing block and the second pressing block;

[0040] Figure 3 It is a structure diagram of the second cavity in the cylinder body;

[0041] Figure 4 It is a structure diagram of the anchoring mechanism;

[0042] Figure 5 It is a structure diagram of the fixing disc;

[0043] In the figure: 1, center tube, 2, locking mechanism, 21, screw rod, 22, nut, 23, first push block, 24, outer sleeve, 25, friction block, 3, sealing mechanism, 31, first sealing cylinder, 32, second sealing cylinder, 321, first sealing block, 322, second sealing block, 323, reset spring, 324, first pressing block, 3241, first partition, 325, second pressing block, 3251, second partition, 33, third sealing cylinder, 4, anchoring mechanism, 41, fixed disc, 411, first track, 42, driving disc, 421, second track, 43, anchor block, 44, cylinder, 441, first cavity, 442, second cavity, 443, third cavity, 444, fourth cavity, 45, piston, 46, second push block, 47, partition plate, 48, sealing plate, 49, unsealing spring, 5, positioning sleeve. DETAILED DESCRIPTION

[0044] The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor also fall within the scope of protection of the present application.

[0045] As shown in the figure, the present embodiment proposes Figures 1-5

[0046] High-temperature-resistant 250-degree expansion-type fracturing packer, comprising a center tube 1, a locking mechanism 2, a sealing mechanism 3 and an anchoring mechanism 4 arranged in sequence on the center tube 1, the sealing mechanism 3 being sealed under the action of the locking mechanism 2, the sealing mechanism 3 comprising:

[0047] A first sealing cylinder 31, a second sealing cylinder 32 and a third sealing cylinder 33 are arranged in sequence on the center tube 1, and pressing blocks are arranged between the first sealing cylinder 31 and the second sealing cylinder 32 and between the second sealing cylinder 32 and the third sealing cylinder 33, the second sealing cylinder 32 comprising:

[0048] A first sealing block 321, the first sealing block 321 being a plurality of blocks uniformly distributed around the center tube 1 and being capable of sliding radially along the center tube 1;

[0049] A second sealing block 322, the second sealing block 322 being a plurality of blocks uniformly distributed around the center tube 1 and being capable of sliding radially along the center tube 1, the second sealing block 322 being arranged at intervals with the first sealing block 321, and the second sealing block 322 being sealed with the two first sealing blocks 321 adjacent thereto;

[0050] A reset spring 323 for providing elastic force to make the first sealing block 321 and the second sealing block 322 close to the center tube 1;

[0051] ​The first sealing cylinder 31 and the second sealing cylinder 32 can be compressed under the action of the locking mechanism 2, and the first sealing block 321 and the second sealing block 322 can slide outward under the action of the locking mechanism 2.

[0052] The anchoring mechanism 4 is used to be fixed in the pipe string when the packer is set, and the sealing mechanism 3 is driven by the locking mechanism 2 to realize the sealing of the pipe string, complete the setting, the sealing mechanism 3 adopts a three-layer sealing cylinder design, wherein the first sealing cylinder 31 and the third sealing cylinder 33 adopt heat-resistant rubber, and the sealing between the pipe string is realized by compression under the action of the locking mechanism 2 during setting; the second sealing cylinder 32 is composed of a plurality of first sealing blocks 321 and a plurality of second sealing blocks 322, and the first sealing block 321 and the second sealing block 322 slide outward under the action of the locking mechanism 2 during setting, and seal with the pipe string, and during unsetting, the first sealing block 321 and the second sealing block 322 are retracted inward by the reset spring 323, and the first sealing block 321 and the second sealing block 322 are always sealed, ensuring the sealing effect. Through the design of three-layer sealing structure, the sealing effect required during setting can be effectively achieved, and the three-layer sealing has better heat insulation effect, and can still ensure good sealing at high temperature. The second sealing cylinder 32 changes the sealing mode of commonly used rubber compression, and adopts sealing block sliding to seal, avoiding the influence of rubber material aging on sealing effect due to high temperature. The above scheme can effectively improve the sealing effect of the packer at high temperature and increase the service life.

[0053] The first pressure block 324 is arranged between the first sealing cylinder 31 and the second sealing cylinder 32, the first pressure block 324 is provided with a first inclined surface, a plurality of first partition plates 3241 are arranged on the first inclined surface in a circumferential direction, and the first sealing block 321 is arranged between two adjacent first partition plates 3241;

[0054] The second pressure block 325 is arranged between the second sealing cylinder 32 and the third sealing cylinder 33, the second pressure block 325 is provided with a second inclined surface, a plurality of second partition plates 3251 are arranged on the second inclined surface in a circumferential direction, and the second sealing block 322 is arranged between two adjacent second partition plates 3251;

[0055] The first inclined surface and the second inclined surface form a space with an outside larger than an inside, and the first partition plate 3241 and the second partition plate 3251 are arranged at intervals.

[0056] The pressure provided by the locking mechanism 2 makes the first sealing block 321 slide outward along the first inclined surface and the second sealing block 322 slide outward along the second inclined surface, the partition plates are arranged to facilitate the installation of the sealing blocks and provide a sliding track for the sealing blocks, and the structure is simple and effective.

[0057] The locking mechanism 2 comprises:

[0058] The screw rod 21 is rotationally arranged on the central pipe 1.

[0059] Nut 22, arranged on screw rod 21, slides along the generatrix direction of central pipe 1;

[0060] First push block 23, under the action of nut 22, slides along the generatrix direction of central pipe 1, and first push block 23 is in contact with first sealing cylinder 31.

[0061] During setting, nut 22 is driven to slide along the generatrix direction of central pipe 1 by rotating screw rod 21, so that nut 22 pushes first push block 23, and first push block 23 applies pressure to first sealing cylinder 31, so that sealing mechanism 3 realizes sealing, and the self-locking property of nut 22 and screw rod 21 can ensure stability during setting, and only needs to rotate screw rod 21 in the opposite direction during unsetting, so that control is simple and convenient to use.

[0062] When setting or unsetting is performed, screw rod 21 is connected with a device that can provide torque, such as a motor or an oil motor, and is removed after setting or unsetting is completed, without being left in the pipe string, thereby ensuring safety.

[0063] Locking mechanism 2 further comprises:

[0064] Outer sleeve 24, which is arranged on screw rod 21, has a track inside for guiding nut 22;

[0065] Friction block 25, which is arranged on outer sleeve 24 by an elastic member, can slide along the radial direction of outer sleeve 24.

[0066] The end surface of friction block 25 for contacting the pipe string is provided with first friction lines along the length direction of the pipe string.

[0067] Outer sleeve 24 is arranged on screw rod 21 and nut 22, and has relative rotation with screw rod 21 without relative sliding, and the inside of outer sleeve 24 is provided with a track for guiding nut 22, and friction block 25 is arranged on outer sleeve 24 to avoid rotation of outer sleeve 24, and the elastic member makes friction block 25 contact the inner wall of the pipe string, and the first friction lines on the pipe string along the length direction of the pipe string can ensure that the packer normally advances and retreats in the pipe string, and provide friction force to avoid rotation of outer sleeve 24 when outer sleeve 24 has a tendency to rotate.

[0068] Anchor mechanism 4 comprises:

[0069] Fixed disc 41, which is provided with a plurality of first tracks 411 in the radial direction;

[0070] Drive disc 42, which is provided with a plurality of second tracks 421;

[0071] Anchor blocks 43, which are a plurality of, and slide relative to first tracks 411 and second tracks 421, and slide along first tracks 411 under the action of drive disc 42;

[0072] A driving mechanism is used to drive the rotation of the disc 42.

[0073] The anchor mechanism is also driven by rotation. The driving mechanism drives the rotation of the disc 42, and the anchor block 43 which slides relative to the disc 42 and the fixed disc 41 moves radially, moving outward during the setting, and the anchor block 43 is pressed against the inner wall of the pipe string, ensuring the stability of the packer during setting, and it will not be pushed by the pressure when bearing the pressure.

[0074] The driving mechanism comprises:

[0075] A cylinder 44, which is provided with a first cavity and a second cavity,

[0076] A piston 45, which is slidingly arranged in the first cavity and divides the first cavity into a first chamber 441 and a second chamber 442;

[0077] A second push block 46, which is fixedly connected with the piston 45 and in contact with the third sealing cylinder 33;

[0078] A partition plate 47 and a sealing plate 48, the partition plate 47 is fixedly arranged in the second cavity, and the sealing plate 48 is rotationally arranged in the second cavity, the partition plate 47 and the sealing plate 48 divide the second cavity into a third chamber 443 and a fourth chamber 444, the third chamber 443 and the fourth chamber 444 are in communication and filled with oil, and the sealing plate 48 is coaxially arranged with the disc 42;

[0079] A releasing spring 49, which is arranged in the second cavity and provides a spring force for moving the piston 45 in a direction in which the volume of the first chamber 441 is reduced.

[0080] The driving mechanism is hydraulically driven. When setting, the pressure applied by the locking mechanism 2 to the sealing mechanism 3 is transmitted to the driving mechanism through the second push block 46, the piston 45 reduces the volume of the oil storage space formed by the communication between the second chamber 442 and the third chamber 443, the oil pushes the sealing plate 48 to rotate, and the sealing plate 48 drives the disc 42 to rotate when rotating, thereby realizing the anchoring of the anchor mechanism 4; when releasing, the locking mechanism 2 no longer applies pressure to the sealing mechanism 3, the second push block 46 is no longer under pressure, and the piston 45 moves in a direction in which the volume of the first chamber 441 is reduced under the action of the releasing spring 49, the volume of the second chamber 442 and the third chamber 443 increases, the pressure difference causes the sealing plate 48 to rotate in the opposite direction, and the anchor mechanism 4 is released from the anchoring state, which is simple and practical.

[0081] It also comprises a positioning sleeve 5, which is fixedly connected with the fixed disc 41.

[0082] The positioning sleeve 5 is used for positioning the packer in the pipe string, and the fixed disc 41 is fixedly connected with the positioning sleeve 5 to ensure that the fixed disc 41 does not rotate during setting or releasing.

[0083] The anchor block 43 is provided with a second frictional pattern in the direction perpendicular to the length of the pipe string at the end surface in contact with the pipe string.

[0084] The anchor block 43 mainly functions to anchor the packer during setting, and the frictional force in the length direction of the pipe string is increased by providing the second frictional pattern on the end surface in contact with the pipe string, thus being more stable.

[0085] The packer is used by first connecting the oil motor with the screw rod 21, and then lowering them into the pipe string together. The positioning sleeve 5 functions to position the packer when the packer is in place. During setting, the oil motor drives the screw rod 21 to rotate, the screw rod 21 rotates to drive the nut 22 to slide in the track, the nut 22 pushes the first push block 23, the first push block 23 pushes the entire sealing mechanism 3 to move, and the second push block 46 pushes the piston 45 to move, so that the sealing plate 48 drives the driving disc 42 to rotate, thus causing the anchor block 43 to slide outward and anchor on the pipe string. After the anchor block 43 is anchored on the pipe string, the second push block 46 cannot continue to move, and the first push block 23 continues to move to press the sealing mechanism 3 together with the second push block 46. The first sealing cylinder 31 and the third sealing cylinder 33 are compressed to seal with the inner wall of the pipe string, and the first sealing block 321 and the second sealing block 322 of the second sealing cylinder 32 slide outward to seal with the inner wall of the pipe string. When the sealing is completed, the packer is set. At this time, the oil motor can be removed from the screw rod 21 and taken out of the pipe string.

[0086] During unsetting, the oil motor needs to be connected to the screw rod 21, the oil motor drives the screw rod 21 to rotate in the opposite direction, the nut 22 slides in the opposite direction, the force applied to the first push block 23 gradually decreases, the first sealing cylinder 31 and the third sealing cylinder 33 are restored under the action of their own elasticity, the second sealing cylinder 32 is restored under the action of the reset spring 323, and the unsetting spring 49 causes the piston 45 to move in the direction of reducing the volume of the first cavity 441, so that the sealing plate 48 drives the driving disc 42 to rotate in the opposite direction, the anchor block 43 is retracted inward, and unsetting is completed.

[0087] The above is only a preferred embodiment of the present application, and is not used to limit the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A high-temperature resistant 250°C expansion fracturing packer, comprising a central tube (1), a locking mechanism (2), a sealing mechanism (3), and an anchoring mechanism (4) sequentially arranged on the central tube (1), wherein the sealing mechanism (3) performs sealing under the action of the locking mechanism (2), characterized in that, The sealing mechanism (3) comprises: The first sealing cylinder (31), the second sealing cylinder (32) and the third sealing cylinder (33) are sequentially arranged on the central pipe (1), the first sealing cylinder (31) and the second sealing cylinder (32), the second sealing cylinder (32) and the third sealing cylinder (33) are provided with a pressing block therebetween, and the second sealing cylinder (32) comprises: A first sealing block (321) is provided, and a plurality of first sealing blocks (321) are uniformly distributed along the circumference of the central pipe (1) and can slide radially along the central pipe (1); A second sealing block (322) is provided, and a plurality of second sealing blocks (322) are uniformly distributed along the circumference of the central pipe (1) and can slide radially along the central pipe (1), the second sealing blocks (322) are arranged at intervals from the first sealing blocks (321), and each second sealing block (322) is sealed with two first sealing blocks (321) adjacent thereto; A reset spring (323) is arranged to provide elastic force for moving the first sealing blocks (321) and the second sealing blocks (322) to be close to the central pipe (1); The first sealing cylinder (31) and the second sealing cylinder (32) can be compressed under the action of the locking mechanism (2), and the first sealing blocks (321) and the second sealing blocks (322) can slide outward under the action of the locking mechanism (2); A first pressing block (324) is arranged between the first sealing cylinder (31) and the second sealing cylinder (32), a first inclined surface is arranged on the first pressing block (324), a plurality of first partition plates (3241) are arranged on the first inclined surface, and the first sealing blocks (321) are arranged between two adjacent first partition plates (3241); A second pressing block (325) is arranged between the second sealing cylinder (32) and the third sealing cylinder (33), a second inclined surface is arranged on the second pressing block (325), a plurality of second partition plates (3251) are arranged on the second inclined surface, and the second sealing blocks (322) are arranged between two adjacent second partition plates (3251); The first inclined surface and the second inclined surface oppositely form a space with an outer side larger than an inner side, and the first partition plates (3241) and the second partition plates (3251) are arranged at intervals.

2. The high temperature 250 degree stretch fracturing packer of claim 1, wherein, Further comprising: The locking mechanism (2) comprises: A screw rod (21) is rotatably arranged on the central pipe (1); A nut (22) is arranged on the screw rod (21) and can slide along the generatrix of the central pipe (1); A first push block (23) slides along the generatrix of the central pipe (1) under the action of the nut (22), and the first push block (23) is in contact with the first sealing cylinder (31).

3. The high temperature 250 degree stretch fracturing packer of claim 2, wherein, The locking mechanism (2) further comprises: An outer sleeve (24) is arranged on the screw rod (21), and an inner track is arranged in the outer sleeve (24) to guide the nut (22); A friction block (25) is arranged on the outer sleeve (24) by an elastic member and can slide radially along the outer sleeve (24).

4. The high temperature 250 degree stretch fracturing packer of claim 3, wherein, The friction block (25) is provided with a first friction pattern along the length direction of the pipe column on the end surface for contacting the pipe column.

5. The 250-degree HT expandable frac packer of claim 1, wherein, The anchoring mechanism (4) comprises: A fixed disc (41) provided with a plurality of first tracks (411) in the radial direction; A driving disc (42) provided with a plurality of second tracks (421); A plurality of anchor blocks (43) sliding relative to the first tracks (411) and the second tracks (421), and sliding along the first tracks (411) under the action of the driving disc (42); A driving mechanism for driving the driving disc (42) to rotate.

6. The high temperature 250 degree stretch fracturing packer of claim 5, wherein, The driving mechanism comprises: A cylinder (44) provided with a one-layer cavity and a two-layer cavity, A piston (45) slidingly arranged in the one-layer cavity, dividing the one-layer cavity into a first cavity (441) and a second cavity (442); A second push block (46) fixedly connected with the piston (45) and in contact with the third sealing cylinder (33); A partition plate (47) fixedly arranged in the two-layer cavity and a sealing plate (48) rotatably arranged in the two-layer cavity, the partition plate (47) and the sealing plate (48) dividing the two-layer cavity into a third cavity (443) and a fourth cavity (444), the third cavity (443) and the fourth cavity (444) being in communication and filled with oil, and the sealing plate (48) being coaxially arranged with the driving disc (42); An unsealing spring (49) arranged in the two-layer cavity and providing a spring force for moving the piston (45) in a direction to reduce the volume of the first cavity (441).

7. The high temperature 250 degree stretch fracturing packer of claim 6, wherein, Further comprising a positioning sleeve (5) fixedly connected with the fixed disc (41).

8. The high temperature 250 degree stretch fracturing packer of claim 5, wherein, The anchor block (43) is provided with a second friction pattern perpendicular to the length direction of the pipe column on the end surface for contacting the pipe column. The anchoring mechanism (4) comprises: A fixed disc (41) provided with a plurality of first tracks (411) in the radial direction; A driving disc (42) provided with a plurality of second tracks (421); A plurality of anchor blocks (43) sliding relative to the first tracks (411) and the second tracks (421), and sliding along the first tracks (411) under the action of the driving disc (42); A driving mechanism for driving the driving disc (42) to rotate. The driving mechanism comprises: A cylinder (44) provided with a one-layer cavity and a two-layer cavity, A piston (45) slidingly arranged in the one-layer cavity, dividing the one-layer cavity into a first cavity (441) and a second cavity (442); A second push block (46) fixedly connected with the piston (45) and in contact with the third sealing cylinder (33); A partition plate (47) fixedly arranged in the two-layer cavity and a sealing plate (48) rotatably arranged in the two-layer cavity, the partition plate (47) and the sealing plate (48) dividing the two-layer cavity into a third cavity (443) and a fourth cavity (444), the third cavity (443) and the fourth cavity (444) being in communication and filled with oil, and the sealing plate (48) being coaxially arranged with the driving disc (42); An unsealing spring (49) arranged in the two-layer cavity and providing a spring force for moving the piston (45) in a direction to reduce the volume of the first cavity (441). Further comprising a positioning sleeve (5) fixedly connected with the fixed disc (41). The anchor block (43) is provided with a second friction pattern perpendicular to the length direction of the pipe column on the end surface for contacting the pipe column.

Images