A reliable, easy-to-handle mechanically-set, washable packer and method of using same

Abstract

The application discloses a reliable and easy-to-handle mechanical seat seal type washable well packer and a use method thereof, and relates to the technical field of oil and gas well packers. The anchor sealing mechanism and the setting and locking mechanism jointly form a backwash mechanism. The application also discloses a reverse-thread safety mechanism. When the packer fails to be unsealed, the reverse-thread safety mechanism can be used to release the packer, and after the release, a wellbore processing tool can be used to mill the hydraulic anchor. The reverse-thread safety mechanism reduces the risk of downhole accidents and improves the adaptability and safety of the tool.

Description

Technical Field

[0001] This invention relates to the field of oil well packer technology, specifically to a reliable and easy-to-handle mechanically set washable packer and its usage method. Background Technology

[0002] Mechanically set packers with an upward and downward setting method are simple, reliable, and re-set. They are widely used in oilfield acidizing, leak detection, and other processes, effectively improving process flexibility and efficiency.

[0003] Currently used mechanically set packers with a lifting-lowering setting method have certain limitations:

[0004] When a mechanically set packer with a lifting and lowering method is lowered into the well, the mechanical components of the packer are prone to actuation due to the friction between the tubing and the inner wall of the casing. This can cause the rubber sleeve to expand and set prematurely or be damaged by friction, affecting the reliability of the tool.

[0005] Mechanically set packers with an upward and downward setting method are often used in environments with repeated setting and pressurization due to their simple setting and repeated setting and unsetting characteristics. However, they are prone to damage to the packer sleeve due to the creep of the tubing caused by changes in working conditions, which affects the safety of the tool.

[0006] Mechanically set packers with a lifting and lowering setting method lack a backwashing channel. If applied to water injection process tubing, backwashing wells cannot be implemented, which restricts the overall function and application effect of the tubing and affects the adaptability of the tool.

[0007] Publication (Announcement) No.: CN111594092B discloses a method for using packer backwashing, including: Step 1: Connect the Y221 packer to the tubing string and run it down the well. After the packer is lowered to the predetermined position, lift the tubing string outside the well and rotate the tubing string. Then continue to lower the tubing string to complete the packer setting. Step 2: When backwashing is required, inject fluid into the annulus to increase the casing pressure. When the pressure reaches the set value, push the backwash piston sleeve (105) to compress the backwash spring (102) and move it upward, squeezing the blocking ring (103) to ensure that the backwash mechanism is open. Step 3: When the pressure inside the casing disappears, the backwash piston sleeve (105) returns to its original position under the action of the backwash spring (102), which can close the well washing channel. Step 4: When unsealing is required, lift the tubing string outside the well, and the rubber sleeve (108) resets to complete the unsealing of the packer.

[0008] The existing technology lacks a drop-off mechanism, making it difficult to remove the tubing after a failed unsealing attempt.

[0009] Publication No. CN110424922A discloses a backwashing method for a non-metallic anchored packer. The packer used in this method includes an upper connector, a central tube, and a lower connector connected sequentially from top to bottom. The central tube has an anchoring structure, a compression structure, a release head, a sealing structure, and a setting structure arranged from top to bottom. A flow pipe is provided between the compression structure and the central tube, forming an annular backwashing channel. A backwashing inlet is located on the upper side of the flow pipe, and a backwashing outlet is located on the setting structure. After setting, the anchor claw protrudes from the packer body, supporting it on the casing wall and anchoring the injection string. This reduces string creep caused by pressure fluctuations, improves the packer's sealing effect, and extends the packer's sealing life. The anchor claw is made of high-strength vulcanized rubber, ensuring no damage to the casing after anchoring. It also features self-locking setting and backwashing functions. This method simplifies the injection tool string, reduces injection tool costs, and extends the effectiveness of the injection string.

[0010] The existing technology lacks a drop-off mechanism, making it difficult to remove the tubing after a failed unsealing attempt.

[0011] Publication No. CN115992661A discloses a long-lasting anchoring tool and method, including an outer protection mechanism, an inner protection mechanism, a well-washing mechanism, and an anchoring mechanism. The outer protection mechanism includes a connecting sleeve, a protective cylinder, a sealing sleeve, and a starting piston. The inner protection mechanism includes a pressure-transmitting piston, an outer cylinder, and a lower central tube, with a protective fluid placed inside. The well-washing mechanism includes a well-washing sleeve, a well-washing spring, an upper piston, a lower piston, and a sealing element. The anchoring mechanism includes a main body, a spring, anchor claws, and a pressure plate. This prior art can effectively improve the service life and retrieval reliability of the anchoring tool, further reducing the risk of subsequent replacement, thereby extending the service life of the supporting tubing string. It is of great significance for further improving the level of fine-scale water injection in the development of old oilfields.

[0012] The existing technology lacks a drop-off mechanism, making it difficult to remove the tubing after a failed unsealing attempt.

[0013] In summary, the technical solutions, technical problems to be solved, and beneficial effects of the above-disclosed technologies are all different from those of the present invention. Regarding the more technical features, technical problems to be solved, and beneficial effects of the present invention, the above-disclosed technical documents do not provide any technical inspiration. Summary of the Invention

[0014] In view of the above-mentioned defects in the existing technology, the purpose of this invention is to provide a reliable and easy-to-handle mechanically set washable packer and its usage method, which solves the problem that it is difficult to remove the tubing string after the existing packer fails to be unsealed.

[0015] To achieve the above objectives, the present invention adopts the following technical solution:

[0016] A reliable and easy-to-handle mechanically set-sealed washable packer includes an anchoring and sealing mechanism and a setting and locking mechanism connected in sequence; the anchoring and sealing mechanism and the setting and locking mechanism together constitute a backwashing mechanism;

[0017] It also includes an inverted safety mechanism; the inverted safety mechanism is disposed above the anchoring and sealing mechanism.

[0018] The inverted safety mechanism includes an upper connector, a locking block, and a first central tube;

[0019] The inner wall of the upper end of the first central tube is connected to the outer wall of the lower end of the upper connector by a reverse thread. The locking block passes through the upper end of the first central tube and is inserted into the upper connector. A shearing nail sleeve is fitted on the outer wall of the first central tube below the upper connector.

[0020] The shear pin sleeve is connected to the first central tube via shear pins, and the first central tube is provided with a first pressure transmission hole at the corresponding position on the upper end of the shear pin sleeve;

[0021] The outer wall of the clipper sleeve is connected to a locking sleeve by threads. The locking sleeve covers the locking block, and the inner wall of the locking sleeve above the locking block is provided with a receiving groove.

[0022] The anchoring and sealing mechanism includes an anchoring part and a sealing part connected in sequence.

[0023] The anchoring component includes hydraulic anchor teeth and hydraulic anchor body;

[0024] The first central tube has a first external thread on its outer wall below the shear pin sleeve. The upper inner wall of the hydraulic anchor body is connected to the first external thread. The lower part of the first external thread of the first central tube is inserted into the hydraulic anchor body.

[0025] The hydraulic anchor teeth are fixed at both ends to the outer wall of the hydraulic anchor body. The first anchor body has a through hole in the area corresponding to the hydraulic anchor teeth. A first piston is installed in the through hole. A first spring is installed between the first piston and the hydraulic anchor teeth. At least two sets of hydraulic anchor teeth, through holes, first pistons and first springs are provided.

[0026] The sealing part includes an upper outer sleeve, an upper support body, a rubber sleeve, a lower support body, and a second central tube;

[0027] The upper jacket is connected to the hydraulic anchor body by a thread, the upper end of the second central tube is connected to the inner wall of the upper end of the upper jacket by a thread, the outer wall of the upper jacket is provided with a downwardly extending protrusion, and the inner wall of the lower end of the protrusion is threaded to an upper support body;

[0028] The lower end of the upper support body is threaded with a rubber sleeve seat.

[0029] The rubber sleeve seat does not contact the second central tube. At least two rubber sleeves are fitted on the rubber sleeve seat, and a spacer ring is provided between each pair of rubber sleeves. A lower support body is provided on the lower outer wall of the rubber sleeve seat.

[0030] The lower support body can slide relative to the rubber sleeve seat, the upper end of the lower support body is in contact with the rubber sleeve, and the lower end of the lower support body is connected to the seat locking mechanism.

[0031] A second spring is provided at the upper end of the annular space between the protrusion and the second central tube, and a second piston is provided at the lower end of the second spring. The lower end surface of the second piston is an outer conical surface, and a second pressure transmission hole is provided at the corresponding position of the upper end of the second spring in the second central tube.

[0032] The upper end face of the upper support is an inner conical surface, the lower end face of the second piston is in contact with the upper end face of the upper support, the upper support does not contact the second central tube, and the protrusion is provided with a water inlet hole above the upper end face of the upper support.

[0033] The seat locking mechanism includes a lower outer jacket and a spring body;

[0034] The lower outer sleeve has a threaded connection to the inner wall of the lower end of the sleeve. The lower end of the second central tube is inserted into the inner wall of the upper end of the lower joint. The inner wall of the lower outer sleeve is provided with a limiting boss. The second central tube is provided with a groove in the corresponding area of ​​the lower outer sleeve. A spring body is provided between the second central tube and the lower outer sleeve. The spring body has at least two through grooves evenly opened around the axial center. The outer wall of the connecting rib between the through grooves is provided with a first engaging part, which sits on the upper end face of the convex ring. The inner wall of the spring body is provided with a second engaging part, and the upper end face of the second engaging part contacts the upper end face of the groove.

[0035] The lower outer sleeve is threaded to the lower outer wall of the lower support body. The lower outer sleeve is provided with a water outlet hole below the lower support body. The rubber sleeve seat is provided with a drainage hole at the corresponding position of the lower support body. When the lower support body moves upward to squeeze the rubber sleeve to complete the setting seal, the water outlet hole and the drainage hole coincide.

[0036] The hydraulic anchor body and hydraulic anchor teeth are made of drillable materials and can be milled by well drilling tools.

[0037] The reverse thread is a left-hand thread, and the thread is a right-hand thread.

[0038] A method for using a reliable and easy-to-handle mechanically set washable well packer includes the following steps:

[0039] S1. Connecting the tubing string and lowering it into the well: Assemble a reliable and easy-to-handle mechanically set washable packer and connect it to the designed position on the tubing string, then lower it into the well. When assembling a reliable and easy-to-handle mechanically set washable packer, connect the reverse safety mechanism, anchoring sealing mechanism, and setting locking mechanism in sequence. Select a suitable spring body according to the downhole environment, and preset the packer setting force through the spring body material to ensure that the tool is safely lowered into the well and does not set midway.

[0040] S2, Setting: After the packer is lowered to the design depth, the tailpipe supports the "lowering" of the tubing string. The lower connector supports the lower outer sleeve to keep it in a fixed position. The second central tube drives the spring body to move downward. The tubing string is "lowered" to apply setting force. The spring body deforms and breaks through the lower outer sleeve limit. The second central tube drives the upper outer sleeve to move downward, squeezing the rubber sleeve out to complete the setting. At this time, the drain hole and the outlet hole coincide.

[0041] S3, Water Injection: After the oil pipe is pressurized, the oil pipe pressure acts on the upper end face of the second piston through the second pressure transmission hole, which closes the backwash channel. At the same time, the oil pipe pressure pushes the first piston through the gap between the first central pipe and the hydraulic anchor body, which causes the hydraulic anchor teeth to be pushed out, anchoring the tubing and preventing the packer from creeping.

[0042] S4. Well washing: After the tubing is depressurized, well washing fluid is injected from the annulus of the tubing and casing. The well washing fluid enters through the inlet hole, causing the second piston to move against the elastic force of the second spring under the backwash pressure. The backwash channel is opened, and the well washing fluid is sprayed out from the outlet hole through the backwash channel. It passes through a reliable and easy-to-handle mechanically set-sealed washable packer.

[0043] S5. Unsealing: After the tubing is depressurized, the hydraulic anchor tooth retracts, and the second piston moves against the second spring force under the pressure of the lower part of the rubber sleeve, releasing the pressure of the lower casing and "lifting" the tubing string, which drives the packer body to move upward. The rubber sleeve retracts, and the tubing string continues to be "lifted". The elastic deformation of the spring body is restored to the initial position through the lower outer sleeve limiting boss.

[0044] S6. Release: If the packer fails to release, pressure is applied to the tubing to cut the shear pins, causing the outer sleeve to move down and the locking block to pop out into the receiving groove. The upper connector and the first central tube are then disengaged by clockwise rotation. The release part, hydraulic anchor body, and hydraulic anchor teeth can be milled using wellbore treatment tools.

[0045] Compared with the prior art, the present invention has the following advantages:

[0046] 1. It can be repeatedly set and the setting force required to start the packer can be adjusted by changing the material of the spring body, which effectively improves the adaptability of the tool;

[0047] 2. After the tubing is depressurized, the pressure in the lower casing can be released through the backwash channel. The packer has no additional unsealing load, which improves the safety of the tool.

[0048] 3. If the packer fails to release, it can be released by the inverted safety mechanism. After release, the hydraulic anchor can be milled using wellbore treatment tools to reduce the risk of downhole accidents and further improve the tool's adaptability and safety. Attached Figure Description

[0049] Figure 1 This is a schematic diagram of the structure of a reliable and easy-to-handle mechanically set washable well packer according to the present invention;

[0050] Figure 2 This is a schematic diagram of the inverted safety mechanism of a reliable and easy-to-handle mechanically set and washable well packer according to the present invention;

[0051] Figure 3 This is a schematic diagram of the anchoring and sealing mechanism of a reliable and easy-to-handle mechanically set washable well packer according to the present invention;

[0052] Figure 4 This is a schematic diagram of the setting and locking mechanism of a reliable and easy-to-handle mechanically set and washable well packer according to the present invention;

[0053] Figure 5 This is a schematic diagram of the spring body structure in the setting and locking mechanism of a reliable and easy-to-handle mechanically set and washable well packer according to the present invention;

[0054] In the diagram: 1. Inverted safety mechanism; 101. Upper connector; 102. Locking sleeve; 103. Locking block; 104. First central tube; 105. Shear pin sleeve; 2. Anchoring and sealing mechanism; 201. Hydraulic anchor body; 202. Hydraulic anchor tooth; 203. Upper outer sleeve; 204. Second spring; 205. Second piston; 206. Rubber sleeve; 207. Second central tube; 3. Sealing and locking mechanism; 301. Lower outer sleeve; 302. Spring body; 303. Lower connector. Detailed Implementation

[0055] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Example

[0056] Please see Figure 1 The present invention provides a reliable and easy-to-handle mechanically set-sealed washable packer, comprising a reverse safety mechanism 1, an anchoring and sealing mechanism 2, and a set-sealing mechanism 3 connected in sequence, wherein the anchoring and sealing mechanism 2 and the set-sealing mechanism 3 are provided with a backwashing mechanism;

[0057] Please see Figure 1 , Figure 2 The inverted safety mechanism 1 includes an upper connector 101, a locking block 103, and a first central tube 104. The upper inner wall of the first central tube 104 is connected to the lower outer wall of the upper connector 101 by an inverted thread. The locking block 103 passes through the upper end of the first central tube 104 and is inserted into the upper connector 101. A shear pin sleeve 105 is fitted on the lower outer wall of the first central tube 104 below the upper connector 101. The shear pin sleeve 105 is connected to the first central tube 104 by shear pins. A first pressure transmitting hole is provided at the corresponding position on the upper end of the shear pin sleeve 105. A locking sleeve 102 is threadedly connected to the outer wall of the shear pin sleeve 105. The locking sleeve 102 covers the locking block 103. A receiving groove is provided on the inner wall of the locking sleeve 102 above the locking block 103.

[0058] Please see Figure 1 , Figure 3 The anchoring and sealing mechanism 2 includes an anchoring part and a sealing part connected in sequence;

[0059] The anchoring part includes a hydraulic anchor tooth 202 and a hydraulic anchor body 201; the first central tube 104 has a first external thread on the outer wall below the shear pin sleeve 105, the upper inner wall of the hydraulic anchor body 201 is connected to the first external thread, and the lower part of the first external thread of the first central tube 104 is inserted into the hydraulic anchor body 201.

[0060] The hydraulic anchor tooth 202 is fixed at both ends to the outer wall of the hydraulic anchor body 201. The first anchor body has a through hole in the area corresponding to the hydraulic anchor tooth 202. A first piston is provided in the through hole. A first spring is provided between the first piston and the hydraulic anchor tooth 202. At least two sets of hydraulic anchor tooth 202, through hole, first piston and first spring are provided.

[0061] The sealing part includes an upper outer sleeve 203, an upper support body, a rubber sleeve 206, a lower support body, and a second central tube 207; the upper outer sleeve 203 is threadedly connected to the hydraulic anchor body 201, the upper end of the second central tube 207 is threadedly connected to the upper inner wall of the upper outer sleeve 203, the outer wall of the upper outer sleeve 203 is provided with a downwardly extending protrusion, a second spring 204 is provided at the upper end of the annular space between the protrusion and the second central tube 207, a second piston 205 is provided at the lower end of the second spring 204, the lower end face of the second piston 205 is an outer conical surface, and a second pressure transmission hole is provided at the corresponding position on the upper end of the second spring 204 in the second central tube 207;

[0062] The protrusion is threaded to the inner wall of the lower end of the upper support body. The upper end face of the upper support body is an inner conical surface. The lower end face of the second piston 205 is in contact with the upper end face of the upper support body. The upper support body does not contact the second central tube 207. The protrusion is provided with a water inlet hole above the upper end face of the upper support body.

[0063] The lower inner wall of the upper support body is threaded with a rubber sleeve seat. The rubber sleeve seat does not contact the second central tube 207. At least two rubber sleeves 206 are fitted on the rubber sleeve seat, and a spacer ring is provided between each pair of rubber sleeves 206. The lower outer wall of the lower end of the rubber sleeve seat is provided with a lower support body. The lower support body can slide relative to the rubber sleeve seat. The upper end of the lower support body contacts the rubber sleeve 206, and the lower end of the lower support body is connected to the seat locking mechanism 3.

[0064] Please see Figure 1 , Figure 4 , Figure 5 The seat sealing mechanism 3 includes a lower outer sleeve 301 and a spring body 302; the lower outer sleeve 301 is threadedly connected to the lower outer wall of the lower support body, the lower outer sleeve 301 is provided with a water outlet hole below the lower support body, and the rubber sleeve seat is provided with a drainage hole at the corresponding position of the lower support body. When the lower support body moves upward to squeeze the rubber sleeve 206 to complete the seat sealing, the water outlet hole coincides with the drainage hole.

[0065] The lower outer sleeve 301 is threaded to the inner wall of the lower end of the lower connector 303. The lower end of the second central tube 207 is inserted into the inner wall of the upper end of the lower connector 303. The inner wall of the lower outer sleeve 301 is provided with a limiting boss. The second central tube 207 is provided with a groove in the corresponding area of ​​the lower outer sleeve 301. A spring body 302 is provided between the second central tube 207 and the lower outer sleeve 301. The spring body 302 is evenly provided with at least two through grooves centered on the axial direction. The outer wall of the connecting rib between the through grooves is provided with a first engaging part, which sits on the upper end face of the convex ring. The inner wall of the spring body 302 is provided with a second engaging part. The upper end face of the second engaging part contacts the upper end face of the groove. The first engaging part can follow the bending and contraction of the connecting rib.

[0066] The spring body 302 prevents accidental sealing.

[0067] The hydraulic anchor body 201 and hydraulic anchor teeth 202 are made of drillable materials and can be milled by well drilling tools.

[0068] The reverse thread is a left-hand thread, and the thread is a right-hand thread. Example

[0069] Based on Example 1, the present invention provides a method for using a reliable and easily manageable mechanically set washable well packer, comprising the following steps:

[0070] S1. Connect the tubing string and run it into the well: Connect the reverse safety mechanism 1, the anchoring sealing mechanism 2, and the setting and locking mechanism 3 in sequence. Select a suitable spring body 302 according to the downhole environment. Preset the packer setting force through the material of the spring body 302 to ensure that the tool is safely entered into the well and does not set midway. Connect a reliable and easy-to-handle mechanical setting washable packer to the tubing string design position and run it into the well.

[0071] S2, Setting: After the packer is lowered to the design depth, the tailpipe supports the "lowering" of the tubing string. The lower connector 303 supports the lower outer sleeve 301 to maintain a fixed position. The second central tube 207 drives the spring body 302 to move downward. The tubing string continues to be lowered to apply setting force. The spring body 302 deforms and breaks through the limit of the lower outer sleeve 301. The second central tube 207 drives the upper outer sleeve 203 to move downward, squeezing the rubber cylinder 206 out to complete the setting. At this time, the drainage hole and the outlet hole coincide.

[0072] S3, Water Injection: After the oil pipe is pressurized, the oil pipe pressure acts on the upper end face of the second piston 205 through the second pressure transmission hole, so that the backwash channel is closed. At the same time, the oil pipe pressure pushes the first piston through the gap between the first central pipe 104 and the hydraulic anchor body 201, so that the hydraulic anchor tooth 202 is pushed out, anchoring the pipe string and preventing the packer from creeping.

[0073] S4. Well washing: After the tubing is depressurized, well washing fluid is injected from the annulus of the tubing and casing. The well washing fluid enters through the inlet hole, causing the second piston 205 to move against the spring force of the spring 204 under the backwash pressure. The backwash channel is opened, and the well washing fluid is sprayed out from the outlet hole through the backwash channel. It passes through a reliable and easy-to-handle mechanically set-sealed washable packer.

[0074] S5. Unsealing: After the tubing is depressurized, the hydraulic anchor 202 retracts, and the second piston 205 moves against the spring force of the spring 204 under the pressure of the lower part of the rubber sleeve 206, releasing the pressure of the lower casing and "lifting" the tubing string. This drives the body of a reliable and easy-to-handle mechanically set washable packer to move upward. The rubber sleeve 206 retracts, and the tubing string continues to be "lifted". The elastic deformation of the spring body 302 is restored to its initial position through the limiting boss of the lower outer sleeve 301.

[0075] S6. Release: If the packer fails to release, pressure is applied to the tubing to cut the shear pin sleeve 105, causing the outer sleeve 102 to move down, the locking block 103 to pop out into the receiving groove, and the upper connector 101 to rotate right and disengage from the first central tube 104. The release part, hydraulic anchor body 201, and hydraulic anchor tooth 202 can be milled by wellbore treatment tools.

[0076] All components not discussed in detail in this application, as well as the connection methods of these components, are well-known technologies in this field. They can be directly applied and will not be elaborated further.

[0077] In this invention, the term "multiple" refers to two or more unless otherwise explicitly defined. The terms "install," "connect," "link," and "fix" should be interpreted broadly. For example, "connect" can be a fixed connection, a detachable connection, or an integral connection; "link" can be a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0078] In the description of this invention, it should be understood that the terms "upper," "lower," "left," "right," "front," "rear," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or unit referred to must have a specific orientation or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0079] In the description of this specification, the terms "one embodiment," "some embodiments," "specific embodiment," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0080] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A reliable and easily handled mechanically set washable well packer, comprising an anchoring and sealing mechanism and a setting and locking mechanism connected in sequence; characterized in that, The anchoring and sealing mechanism and the setting and sealing mechanism together constitute the backwashing well mechanism; It also includes an inverted safety mechanism; the inverted safety mechanism is disposed above the anchoring and sealing mechanism; The anchoring sealing mechanism includes a second central tube; The seat locking mechanism includes a lower outer jacket and a spring body; The lower outer sleeve has a threaded connection to the inner wall of the lower end of the sleeve, and the lower end of the second central tube is inserted into the inner wall of the upper end of the lower joint. The inner wall of the lower outer sleeve is provided with a limiting boss. The second central tube is provided with a groove in the corresponding area of ​​the lower outer sleeve. A spring body is provided between the second central tube and the lower outer sleeve. The spring body has at least two through grooves evenly opened around the axial center. The outer wall of the connecting rib between the through grooves is provided with a first engaging part, which sits on the upper end face of the convex ring. The inner wall of the spring body is provided with a second engaging part, and the upper end face of the second engaging part contacts the upper end face of the groove. A rubber sleeve seat is provided at the upper end of the lower support body; The lower outer sleeve is threaded to the lower outer wall of the lower support body. The lower outer sleeve is provided with a water outlet hole below the lower support body. The rubber sleeve seat is provided with a drainage hole at the corresponding position of the lower support body. When the lower support body moves upward to squeeze the rubber sleeve to complete the setting seal, the water outlet hole and the drainage hole coincide.

2. The reliable and easily processed mechanically set washable well packer according to claim 1, characterized in that, The inverted safety mechanism includes an upper connector, a locking block, and a first central tube; The inner wall of the upper end of the first central tube is connected to the outer wall of the lower end of the upper connector by a reverse thread. The locking block passes through the upper end of the first central tube and is inserted into the upper connector. A shearing nail sleeve is fitted on the outer wall of the first central tube below the upper connector. The shear pin sleeve is connected to the first central tube via shear pins, and the first central tube is provided with a first pressure transmission hole at the corresponding position on the upper end of the shear pin sleeve; The outer wall of the clipper sleeve is connected to a locking sleeve by threads. The locking sleeve covers the locking block, and the inner wall of the locking sleeve above the locking block is provided with a receiving groove.

3. The reliable and easily processed mechanically set washable well packer according to claim 2, characterized in that, The anchoring and sealing mechanism includes an anchoring part and a sealing part connected in sequence.

4. A reliable and easily processed mechanically set washable well packer according to claim 3, characterized in that, The anchoring part includes a hydraulic anchor tooth and a hydraulic anchor body; the first central tube is provided with a first external thread on the outer wall below the shear pin sleeve, the upper inner wall of the hydraulic anchor body is connected to the first external thread, and the lower part of the first external thread of the first central tube is inserted into the hydraulic anchor body. The hydraulic anchor teeth are fixed at both ends to the outer wall of the hydraulic anchor body. The hydraulic anchor body has a through hole in the area corresponding to the hydraulic anchor teeth. A first piston is installed in the through hole. A first spring is installed between the first piston and the hydraulic anchor teeth. At least two sets of hydraulic anchor teeth, through holes, first pistons, and first springs are provided. The hydraulic anchor body and hydraulic anchor teeth are made of drillable materials and can be milled by well drilling tools.

5. A reliable and easily processed mechanically set washable well packer according to claim 4, characterized in that, The sealing part includes an upper outer sleeve, an upper support body, a rubber sleeve, a lower support body, and a second central tube; The upper jacket is connected to the hydraulic anchor body by a thread, the upper end of the second central tube is connected to the inner wall of the upper end of the upper jacket by a thread, the outer wall of the upper jacket is provided with a downwardly extending protrusion, and the inner wall of the lower end of the protrusion is threaded to an upper support body; The lower end of the upper support body is threaded with a rubber sleeve seat. The rubber sleeve seat does not contact the second central tube. At least two rubber sleeves are fitted on the rubber sleeve seat, and a spacer ring is provided between each pair of rubber sleeves. A lower support body is provided on the lower outer wall of the rubber sleeve seat. The lower support body can slide relative to the rubber sleeve seat, the upper end of the lower support body is in contact with the rubber sleeve, and the lower end of the lower support body is connected to the seat locking mechanism.

6. A reliable and easily processed mechanically set washable well packer according to claim 5, characterized in that, A second spring is provided at the upper end of the annular space between the protrusion and the second central tube, and a second piston is provided at the lower end of the second spring. The lower end surface of the second piston is an outer conical surface, and a second pressure transmission hole is provided at the corresponding position of the upper end of the second spring in the second central tube. The upper end face of the upper support is an inner conical surface, the lower end face of the second piston is in contact with the upper end face of the upper support, the upper support does not contact the second central tube, and the protrusion is provided with a water inlet hole above the upper end face of the upper support.

7. A reliable and easily processed mechanically set washable well packer according to claim 6, characterized in that, The reverse thread is a left-hand thread.

8. A method for using a reliable and easily handled mechanically set washable well packer, characterized in that, Includes the following steps: S1. Connecting the tubing string and lowering it into the well: Assemble the reliable and easy-to-handle mechanically set washable packer as described in claim 7, connect it to the designed position on the tubing string, and lower it into the well; S2, Setting: After the packer is lowered to the design depth, the tailpipe support is used to "lower" the tubing string, and the rubber sleeve is squeezed out to complete the setting. At this time, the drain hole and the outlet hole coincide. S3, Water Injection: After the oil pipe is pressurized, the backwash channel is closed, the hydraulic anchor teeth are extended, the tubing is anchored, and the packer is prevented from creeping. S4. Well washing: After the tubing is depressurized, well washing fluid is injected into the annulus of the tubing and casing. The well washing fluid enters through the inlet and sprays out through the outlet, passing through a reliable and easy-to-handle mechanically set packer that can be washed. S5. Unsealing: After the tubing is depressurized, the hydraulic anchor retracts, and the second piston moves against the second spring force under the pressure of the lower part of the rubber sleeve, releasing the pressure of the lower casing, "lifting" the tubing string, driving the packer body to move upward, the rubber sleeve retracts, and the tubing string continues to be "lifted". The elastic deformation of the spring body is restored to the initial position through the lower outer sleeve limiting boss. S6. Release: If the packer fails to release, pressure is applied to the tubing to cut the shear pins, causing the outer sleeve to move down and the locking block to pop out into the receiving groove. The upper connector and the first central tube are then disengaged by clockwise rotation. The release part, hydraulic anchor body, and hydraulic anchor teeth can be milled using wellbore treatment tools.

9. The method of use according to claim 8, characterized in that, When assembling a reliable and easy-to-handle mechanically set washable packer, the inverted safety mechanism, the anchoring sealing mechanism, and the setting and locking mechanism are connected in sequence. A suitable spring body is selected according to the downhole environment. The setting force of the packer is preset by the material of the spring body to ensure that the tool is safely inserted into the well and does not set midway.

10. The method of use according to claim 8, characterized in that, During the setting process, the lower connector supports the lower outer sleeve to maintain a fixed position, the second central tube drives the spring body to move downward, and the tube continues to "lower" to apply setting force. The spring body deforms and breaks through the lower outer sleeve limit, and the second central tube drives the upper outer sleeve to move downward, squeezing the rubber cylinder out to complete the setting process. During water injection, after the oil pipe is pressurized, the oil pipe pressure acts on the upper end face of the second piston through the second pressure transmission hole, which closes the backwash channel. At the same time, the oil pipe pressure pushes the first piston through the gap between the first central pipe and the hydraulic anchor body, causing the hydraulic anchor teeth to extend and anchor the pipe column. During well washing: the washing fluid enters through the inlet hole, causing the second piston to move against the elastic force of the second spring under the backwash pressure. The backwash channel opens, and the washing fluid is sprayed out from the outlet hole through the backwash channel, passing through a reliable and easy-to-handle mechanically set-sealed washable packer.

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