A safety check tube column and method of using the same

Abstract

The application discloses a safe inspection and replacement pipe column and a use method thereof, and relates to the oil field drilling technology field. The safe inspection and replacement pipe column comprises an oil pipe, at least three water distributors are arranged on the oil pipe, a packer is arranged between every two water distributors, one water distributor corresponds to one water injection layer, the lowermost packer is a type II packer, and the remaining packers are type I packers; the type I packer is provided with a first reverse-threading safety part, and the type II packer is provided with a second reverse-threading safety part. The packers are all designed with reverse-threading safety mechanisms, the pipe column can be reverse-threaded and rotated open when being stuck in the later period, the anchoring positions are all made of cast iron materials, the later period milling and drilling are facilitated, the safety accidents of the downhole pipe column are reduced, and the safe inspection and replacement of the pipe column are realized.

Description

Technical Field

[0001] This invention relates to the field of downhole water injection tubing technology in oil extraction, specifically a safe replacement tubing string and its usage method. Background Technology

[0002] Water injection via injection wells is a crucial method for oilfields to maintain formation pressure and improve reservoir recovery. Currently, most oilfields in my country have transitioned from the initial natural energy development stage to water injection development. In the early stages of water injection development, water was injected indiscriminately based on the natural water absorption capacity of different oil layers (i.e., multiple oil layers were injected simultaneously). However, due to the existence of multiple underground oil layers, the water absorption capacity of layers with different permeabilities varies significantly, leading to sudden water injection surges and affecting development efficiency. To resolve this issue, stratified water injection strings are installed in the injection wells to increase the utilization rate of various oil layers.

[0003] For low-permeability reservoirs, due to their low oil layer permeability and high water injection pressure, anchoring tools such as hydraulic anchors, hydraulic slips, or anchoring packers are generally used to prevent tubing creep.

[0004] Publication No. CN112709557B discloses a safe and long-lasting water injection string and construction method for offshore oilfields, comprising: a sand control string and a water injection string, wherein the water injection string is installed inside the sand control string; the sand control string includes at least two filter pipes, each corresponding to a different oil layer, spaced apart from top to bottom on the casing; Y341 packers are installed between each pair of filter pipes, above the uppermost filter pipe, and below the lowermost filter pipe; the water injection string includes at least two adjustable water distributors, each corresponding to a different oil layer, spaced apart from top to bottom on the tubing; a setting switch is connected below each adjustable water distributor; and a hydraulically controlled stratified packer is installed above and below each setting switch. This invention enables the simultaneous installation of the sand control string and the water injection string, saving single-well construction time, and allows for reliable independent maintenance in offshore oilfields, extending the service life of the sand control string.

[0005] The existing technology uses a pull-out switch for forced disconnection, and if one packer fails and gets stuck, all packers need to be abandoned.

[0006] Publication (Announcement) No.: CN108999576B discloses an integrated water injection and sand control tubing string and its process. This integrated tubing string is located within the casing and includes at least one section of water injection and sand control tubing connected downwards from the wellhead via tubing. The water injection and sand control tubing string includes a water distributor, an upper sand-blocking packer, a sand control pipe, and a lower sand-blocking packer connected sequentially from top to bottom. The water distributor and the upper sand-blocking packer are connected via tubing. The sand control pipe includes a central pipe, an outer pipe, and a metal felt mesh located outside the outer pipe. An annular cavity exists between the central pipe and the outer pipe, and the outer pipe has a flow passage. Both the upper and lower sand-blocking packers are provided with flow channels connecting the annular cavity of the sand control pipe to the annulus of the casing. The upper and lower sand-blocking packers are located at the upper and lower ends of the oil layer, respectively, and a closed sand control space can be formed between the upper sand-blocking packer, the lower sand-blocking packer, the outer pipe of the sand control pipe, and the casing. Using this type of tubing can effectively prevent the water injection tubing from being buried by sand, thus improving the service life of the water injection tubing.

[0007] The existing technology uses a reverse-lock safety connector for forced disconnection, and if one packer fails and gets stuck, all packers need to be abandoned.

[0008] Publication No. CN111173483B discloses a time-sharing water injection string and method. The time-sharing water injection string includes an indoor control system, a wellhead control cabinet, a hydraulic control pipeline, tubing, a hydraulic control layered packer, and a hydraulic control water distribution device. Multiple hydraulic control layered packers and water distribution devices are included, with each packer setting its corresponding water distribution device in a different oil layer. The water distribution device uses stepped pressurization on the surface to control the switching of water distribution devices in different oil layers. The wellhead control cabinet monitors and records the injection volume of the oil layer and transmits this data remotely to the indoor control system. Simultaneously, it dynamically monitors the pressure of the hydraulic control pipeline to ensure the pressure remains within a reasonable range. The indoor control system controls the wellhead control cabinet via wired or wireless means. Based on the surface pressurization conditions, the time-sharing water injection string and method activate the corresponding water distribution device. A surface flow meter measures the flow rate of the injection layer, achieving intermittent, layered injection of the water injection well.

[0009] The existing technology does not have a safety release mechanism, which may result in the packer malfunction preventing the tubing from being pulled out.

[0010] 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

[0011] To address the aforementioned deficiencies in existing technologies, the purpose of this invention is to provide a safe replacement tubing string and its usage method. This allows the tubing string to be unscrewed when it becomes stuck, and all anchoring parts are made of cast iron, facilitating subsequent milling and drilling, reducing downhole tubing string safety accidents, and achieving safe replacement of the tubing string.

[0012] To achieve the above objectives, the present invention adopts the following technical solution:

[0013] A safety inspection and replacement tubing string and its usage method are disclosed, comprising an oil tubing with at least three water distributors, a packer between every two water distributors, each water distributor corresponding to a water injection layer, the lowest packer being a type II packer, and the remaining packers being type I packers; the type I packer is provided with a first inverted safety part, and the type II packer is provided with a second inverted safety part.

[0014] A well-washing valve is installed at the bottom of the tubing, and a compensator is installed above the water distributor at the top of the tubing.

[0015] The packer includes a first inverted safety section, a first anchoring and release section, and a first sealing and backwashing section connected in sequence.

[0016] The first inverted safety component includes a first upper connector, a first locking block, and a first central tube;

[0017] The inner wall of the upper end of the first central tube is connected to the outer wall of the lower end of the first upper connector by a reverse thread; the first locking block passes through the upper end of the first central tube and is inserted into the first upper connector;

[0018] The first central tube is fitted with a first shear pin sleeve on its outer wall below the first upper connector;

[0019] The first shear pin sleeve is connected to the first central tube via the first shear pin, and the first central tube is provided with a first pressure transmission hole at the corresponding position on the upper end of the first shear pin sleeve;

[0020] The outer wall of the first shear pin sleeve is connected to a first locking block sleeve by threads. The first locking block sleeve covers the first locking block, and the inner wall of the first locking block sleeve above the first locking block is provided with a first receiving groove.

[0021] The first anchoring and unblocking section includes a second central tube, anchor teeth, and a first anchor body;

[0022] The upper end of the first anchor body is connected to the lower end of the first central tube by a thread, and the two ends of the anchor teeth are fixed to the outer wall of the first anchor body;

[0023] The first anchor body has a first through hole in the area corresponding to the anchor tooth, and the second central tube is fitted into the first anchor body;

[0024] A first piston is provided inside the first through hole, and a first spring is provided between the first piston and the anchor tooth;

[0025] The anchor tooth, the first through hole, the first piston, and the first spring are provided in at least two sets.

[0026] The first sealing and backwashing section includes an upper outer sleeve, an upper support body, a first rubber sleeve, a lower support body, a third central tube, and a lower outer sleeve;

[0027] The upper outer sleeve is connected to the first anchor body by a thread, and the upper end of the third central tube is connected to the inner wall of the upper end of the upper outer sleeve by a thread;

[0028] The outer wall of the upper jacket is provided with a downwardly extending protrusion. A second spring is provided at the upper end of the annular space between the protrusion and the third central tube. 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. A second pressure transmission hole is provided at the corresponding position on the upper end of the second spring in the third central tube.

[0029] The lower end of the protrusion is threaded to an upper support body, the upper end face of the upper support body is an inner conical surface, and the lower end face of the second piston is in contact with the upper end face of the upper support body.

[0030] The upper support body does not contact the third central tube, and the protrusion is provided with a first water inlet hole above the upper end face of the upper support body;

[0031] The lower end inner wall of the upper support body is threadedly connected to a first rubber sleeve seat. The first rubber sleeve seat does not contact the third central tube. At least two first rubber sleeves are fitted on the first rubber sleeve seat. A spacer ring is provided between each two first rubber sleeves. The lower end outer wall of the first rubber sleeve seat is provided with a lower support body. The lower support body can slide relative to the second rubber sleeve seat.

[0032] The upper end of the lower support body contacts the first rubber cylinder. The lower outer wall of the lower support body is threaded with a lower outer sleeve. The lower outer sleeve is provided with a first water outlet hole below the lower support body. The first rubber cylinder seat is provided with a first drainage hole at the corresponding position of the lower support body. When the lower support body moves upward to squeeze the first rubber cylinder to complete the setting and sealing, the first water outlet hole and the first drainage hole coincide.

[0033] The lower end of the outer sleeve is threaded to the inner wall of the lower end of the first lower connector, and the lower end of the third central tube is inserted into the inner wall of the upper end of the first lower connector.

[0034] The inner wall of the lower outer sleeve is provided with a protruding ring, and the third central tube is provided with a groove in the corresponding area of ​​the lower outer sleeve;

[0035] A spring body is provided between the third central tube and the lower outer sleeve. The outer wall of the spring body 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.

[0036] The type II packer includes a fourth central tube, and a second inverted safety part, a second anchoring and release part, a second sealing and backwashing part, and a support and setting part, which are sequentially arranged on the fourth central tube.

[0037] The second inverted safety part includes a second upper connector, a second locking block sleeve, a second locking block, and a second shear pin sleeve;

[0038] The upper inner wall of the fourth central tube is connected to the lower outer wall of the second upper connector by a reverse thread, and the second locking block passes through the upper end of the fourth central tube and is inserted into the second upper connector.

[0039] The fourth central tube is fitted with a second shear pin sleeve on the outer wall below the second upper connector. The second shear pin sleeve is connected to the fourth central tube through the second shear pin. The fourth central tube is provided with a third pressure transmission hole at the corresponding position on the upper end of the second shear pin sleeve.

[0040] The outer wall of the second shear pin sleeve is threadedly connected to a second locking block sleeve, the second locking block sleeve covers the second locking block, and the inner wall of the second locking block sleeve above the second locking block is provided with a second receiving groove.

[0041] The second anchoring release section includes an anchor claw and a second anchor body;

[0042] The second anchor body is fitted onto the fourth central tube, and the two ends of the anchor claw are fixed to the outer wall of the second anchor body. The second anchor body has a second through hole in the area corresponding to the anchor claw. A third piston is installed in the second through hole, and a third spring is installed between the third piston and the anchor claw. At least two sets of anchor claw, second through hole, third piston, and third spring are provided.

[0043] The fourth central tube is provided with a pressure groove in the area corresponding to the anchor claw, and a fourth pressure transmission hole is provided in the pressure groove.

[0044] Two second through holes are opened in the corresponding area of ​​the anchor claw, and the middle of the anchor claw is also fixed to the outer wall of the second anchor body.

[0045] The second sealing and backwashing well section includes an inlet sleeve, an upper retaining ring, and a cone.

[0046] The lower end of the second anchor body is threadedly connected to a water inlet sleeve. A fourth spring is provided above the annular space between the water inlet sleeve and the fourth central tube. A fourth piston is provided at the lower end of the fourth spring. The lower end face of the fourth piston is an outer conical surface.

[0047] The upper retaining ring is threaded to the lower inner wall of the water inlet sleeve. The upper retaining ring is not in contact with the fourth central tube. The upper end face of the upper retaining ring is an inner conical surface. The lower end face of the fourth piston is in contact with the upper end face of the upper retaining ring.

[0048] The water inlet sleeve is provided with a second water inlet hole above the upper end face of the upper baffle ring, and the fourth central tube is provided with a fifth pressure transmission hole at the corresponding position on the upper end of the fourth spring;

[0049] The lower end of the upper retaining ring is threadedly connected to a second rubber sleeve seat. The second rubber sleeve seat does not contact the fourth central tube. At least two second rubber sleeves are fitted on the outer side of the second rubber sleeve seat, and a separator ring is provided between each two second rubber sleeves.

[0050] The cone is disposed on the lower outer wall of the second rubber sleeve seat and can slide relative to the second rubber sleeve seat. An outer cone is disposed at the lower end of the cone and the outer cone is in contact with the fourth central tube. A second water outlet is disposed above the outer cone.

[0051] The supporting seat portion includes a limiting shell;

[0052] The limiting housing is fitted onto the fourth central tube and positioned below the cone. The upper end of the limiting housing is provided with at least two locking grooves, and the middle part is provided with at least two straightening grooves.

[0053] Each slip groove contains a slip, the upper end of which has an inner cone, the outer wall of which has slip teeth, and the lower end of which is fixed in the slip groove.

[0054] Each straightening groove is provided with a straightening block. The outer walls of the upper and lower ends of the straightening groove protrude inward to prevent the straightening block from detaching from the limiting shell. A spring sheet is provided between the straightening block and the straightening groove. The upper and lower ends of the straightening block are provided with inclined surfaces.

[0055] The supporting seat also includes a reversing sleeve and a second lower connector;

[0056] The upper end of the reversing sleeve is threaded to the lower outer wall of the limiting housing, the upper inner wall of the second lower connector is threaded to the lower outer wall of the fourth central tube, and the inner wall of the reversing sleeve is provided with a "7" shaped groove, which is divided into a short groove and a long groove.

[0057] The upper outer wall of the second lower connector is provided with a reversing block. The reversing block is embedded in a short slot or a long slot. When the reversing block is embedded in the short slot, the second lower connector and the reversing sleeve move synchronously. When the reversing block is embedded in the long slot, the second lower connector and the reversing sleeve can slide relative to each other.

[0058] The reverse thread is a left-hand thread, and the thread is a right-hand thread.

[0059] The anchor teeth are made of cast iron and can be milled or drilled.

[0060] The anchor claws are made of cast iron and can be milled or drilled.

[0061] The first locking block sleeve and the first shear pin sleeve are made of cast iron and can be milled or drilled.

[0062] The second locking block sleeve and the second shear pin sleeve are made of cast iron and can be milled or drilled.

[0063] A method for using a safety inspection and replacement tubing string includes the following steps:

[0064] S1. Assemble the tubing string and run it into the well. According to the construction design depth, use tubing of different lengths to assemble the compensator, water distributor, type I packer, type II packer, and well washing valve and run them into the well to deliver them to the design depth, so that one water distributor corresponds to one injection layer.

[0065] S2, Setting: After reaching the design depth, first complete the setting of the lower type II packer. "Lift up" - "right turn" the tubing string. The second lower connector reversing block is in the long groove of the "7" shaped groove on the inner wall of the reversing sleeve. Lower the tubing string. At this time, the slips extend and lock onto the inner wall of the sleeve. Continue to lower the tubing string. The slips tighten, and the cone compresses the second rubber sleeve to achieve setting.

[0066] After the bottom type II packer is set, the tubing continues to be lowered to set the top type I packer. The type I packer will use the bottom type II packer as a support point. At this time, the tubing continues to be lowered. The first lower connector is fixed in place. The first inverted safety part, the first anchor release part, the third central tube, the upper outer sleeve, and the upper support body move downward. The upper support body compresses the first rubber sleeve to achieve setting. At this time, the first outlet hole coincides with the first drainage hole.

[0067] S3. Water injection: Open each level of water distributor, adjust the water distributor to the appropriate opening according to the injection volume requirements, and inject water into the oil pipe;

[0068] After the oil pipe is pressurized, the oil pipe pressure passes through the gap between the second central pipe and the first anchor body, pushes the first piston, and causes the anchor teeth to extend. The oil pipe pressure enters the pressure groove through the fourth pressure transmission hole, pushes the third piston, and causes the anchor claws to extend.

[0069] The oil pipe pressure passes through the second pressure transmission hole, causing the second piston to sit on the upper support body. The oil pipe pressure passes through the fifth pressure transmission hole, causing the fourth piston to sit on the upper retaining ring. The backwash channel is closed.

[0070] S4. Backwashing well: After stopping water injection and depressurizing the tubing, backwashing fluid is injected from the annulus of the casing. The backwashing fluid enters from the first inlet, causing the second piston to move under the backwashing pressure and push the second spring. The first backwashing channel opens, and the backwashing fluid is discharged from the first outlet and passes through a type 1 packer.

[0071] The backwash fluid enters through the second inlet, causing the fourth piston to push the fourth spring under backwash pressure. The second backwash channel opens, and the backwash fluid is discharged from the second outlet, passing through the type II packer.

[0072] The backwash fluid enters the tubing through the backwash valve and returns to the surface.

[0073] S5. Unsealing: After the tubing is depressurized, the anchor teeth and anchor claws of the Type I packer and Type II packer are retrieved, the tubing string is "lifted", the upper support of the Type I packer is moved upward, the first rubber sleeve is retrieved, and the Type I packer is unsealed.

[0074] Continue to "lift" the tubing string. The reversing block of the second lower connector of the type II packer moves from the lower end of the long groove of the reversing sleeve to the upper end. The slip is retracted, the cone is retracted, the second rubber sleeve loses compression, the second rubber sleeve is retracted, and the second packer is unsealed.

[0075] S6, Release and Milling: If the tubing gets stuck, use tubing "pressure boost" - "forward rotation" to release the tubing from the packer in reverse for safety. The remaining part in the well is then milled or drilled.

[0076] When the Type 1 packer is stuck: the tubing is raised to the shearing pressure of the first shear pin, the first shear pin sleeve of the Type 1 packer shears the first shear pin, which drives the locking block sleeve to move down, the first locking block pops out into the first receiving groove, the first upper connector and the first central tube are disengaged and pulled out by right-hand rotation, and the remaining part of the well is milled or drilled using wellbore processing tools.

[0077] When the Type II packer is stuck: the tubing is raised to the shearing pressure of the second shear pin, the second shear pin sleeve of the Type II packer shears the second shear pin, which drives the locking block sleeve to move down, the second locking block pops out into the second receiving groove, the second upper connector and the fourth central tube are disengaged and pulled out, and the remaining part of the well is milled or drilled using wellbore processing tools.

[0078] The shearing pressure of the second shear pin is less than that of the first shear pin.

[0079] Compared with the prior art, the present invention has the following advantages:

[0080] 1. The two-stage packer in the tubing string achieves setting by the weight of the tubing itself, a mechanical setting method that is simple to operate and reliable. The type-one packer's setting mechanism has its setting track positioned on the inner wall of the reversing sleeve, avoiding direct contact with the wellbore fluid, eliminating the risk of affecting track reversal, and improving tool setting reliability. The type-one packer uses the set type-two packer as a support point, relying on the weight of the upper tubing string to compress the rubber sleeve to achieve setting, making setting simple and reliable.

[0081] 2. Lifting the tubing string releases the two-stage packers without additional load, making the operation simple, safe, and reliable. Both packers are designed with a reverse-lock safety mechanism, allowing for unscrewing if the tubing string becomes stuck later. The anchoring parts are made of cast iron, facilitating subsequent milling and drilling, reducing downhole tubing safety accidents, and enabling safe replacement of the tubing string.

[0082] 3. Both packers are designed with backwashing channels, and the tubing string can meet the needs of backwashing in the later stage. Attached Figure Description

[0083] Figure 1 This is a structural schematic diagram of a safety inspection and replacement tube column according to the present invention;

[0084] Figure 2 This is a schematic diagram of the structure of a packer for a safety inspection and replacement string according to the present invention;

[0085] Figure 3 This is a schematic diagram of the structure of a type II packer for a safety replacement string according to the present invention;

[0086] Figure 4 This is a schematic diagram of the second anchoring and unblocking part of the type II packer of a safety replacement string according to the present invention;

[0087] Figure 5 This is a schematic diagram of the second sealing and backwashing well section structure of a type II packer for a safe replacement tubing string according to the present invention;

[0088] In the diagram: 1. Expansion joint; 2. Water distributor; 3. Type I packer; 4. Type II packer; 5. Well-washing valve;

[0089] 6. First inverted safety part; 601. First upper connector; 602. First locking block; 603. First shear pin; 604. First central tube;

[0090] 7. First anchoring and release section; 701. Second central tube; 702. Anchor tooth; 703. First anchor body;

[0091] 8. First sealing and backwashing well section; 801. Upper outer sleeve; 802. Second spring; 803. Second piston; 804. Upper support body; 805. First rubber sleeve; 806. Lower support body; 807. Third central tube; 808. Lower outer sleeve; 809. First lower connector;

[0092] 9. Second inverted safety part; 901. Second upper connector; 902. Second locking block sleeve; 903. Second locking block; 904. Fourth central tube; 905. Second shear pin sleeve;

[0093] 10. Second anchoring and release section; 1001. Anchor claw; 1002. Second anchor body;

[0094] 11. Second sealing and backwashing well section; 1101. Fourth spring; 1102. Fourth piston; 1103. Second rubber sleeve; 1104. Cone;

[0095] 12. Support seat section; 1201. Slipper; 1202. Centering block; 1203. Reversing sleeve; 1204. Second lower connector. Detailed Implementation

[0096] 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.

[0097] Example 1:

[0098] Please see Figure 1 The present invention provides a safety replacement string, including tubing, on which at least three water distributors 2 are provided, and a packer is provided between every two water distributors 2. Each water distributor corresponds to a water injection layer. The bottom packer is a type II packer 4, and the remaining packers are type I packers 3. A well-washing valve 5 is provided at the bottom of the tubing, and a compensator 1 is provided above the top water distributor 2 of the tubing.

[0099] Please see Figure 2 The type 1 packer 3 includes a first inverted safety part 6, a first anchoring and unblocking part 7, and a first sealing and backwashing well part 8 connected in sequence.

[0100] The first inverted safety part 6 includes a first upper connector 601, a first locking block 602, and a first central tube 604. The inner wall of the upper end of the first central tube 604 is connected to the outer wall of the lower end of the first upper connector 601 by an inverted thread. The first locking block 602 passes through the upper end of the first central tube 604 and is inserted into the first upper connector 601. A first shear pin sleeve is fitted on the outer wall of the first central tube 604 below the first upper connector 601. The first shear pin sleeve is connected to the first central tube 604 through a first shear pin 603. A first pressure transmitting hole is provided at the corresponding position on the upper end of the first shear pin sleeve. A first locking block sleeve is threadedly connected to the outer wall of the first shear pin sleeve. The first locking block sleeve covers the first locking block 602. A first receiving groove is provided on the inner wall of the first locking block sleeve above the first locking block 602.

[0101] The first anchoring and unblocking part 7 includes a second central tube 701, an anchor tooth 702, and a first anchor body 703; the upper end of the first anchor body 703 is threadedly connected to the lower end of the first central tube 604, the two ends of the anchor tooth 702 are fixed to the outer wall of the first anchor body 703, the first anchor body has a first through hole in the corresponding area of ​​the anchor tooth 702, the second central tube 701 is fitted into the first anchor body 703, a first piston is provided in the first through hole, and a first spring is provided between the first piston and the anchor tooth 702; at least two sets of the anchor tooth 702, the first through hole, the first piston, and the first spring are provided.

[0102] The first sealing and backwashing well section 8 includes an upper outer sleeve 801, an upper support body 804, a first rubber sleeve 805, a lower support body 806, a third central tube 807, and a lower outer sleeve 808. The upper outer sleeve 801 is threadedly connected to the first anchor body 703. The upper end of the third central tube 807 is threadedly connected to the inner wall of the upper end of the upper outer sleeve 801. The outer wall of the upper outer sleeve 801 is provided with a downwardly extending protrusion. A second spring 802 is provided at the upper end of the annular space between the protrusion and the third central tube 807. A second piston 803 is provided at the lower end of the second spring. The lower end face of the second piston 803 is an outer conical surface. A second pressure transmission hole is provided at the corresponding position on the upper end of the third central tube 807.

[0103] The protrusion has an upper support body 804 threadedly connected to its lower inner wall. The upper surface of the upper support body 804 is an inner conical surface. The lower surface of the second piston 803 is in contact with the upper surface of the upper support body 804. The upper support body 804 does not contact the third central tube 807. The protrusion has a first water inlet hole above the upper surface of the upper support body 804. The upper support body 804 has a first rubber sleeve seat threadedly connected to its lower inner wall. The first rubber sleeve seat does not contact the third central tube 807. At least two first rubber sleeves 805 are fitted on the first rubber sleeve seat. Each pair of first rubber sleeves 805... A spacer ring is provided between the two parts. A lower support body 806 is provided on the lower outer wall of the first rubber sleeve seat. The lower support body 806 can slide relative to the first rubber sleeve seat. The upper end of the lower support body 806 contacts the first rubber sleeve 805. A lower outer sleeve 808 is threadedly connected to the lower outer wall of the lower end of the lower support body 806. A first water outlet hole is provided below the lower support body 806. A first drainage hole is provided at the corresponding position of the first rubber sleeve seat on the lower support body 806. When the lower support body 806 moves upward to squeeze the first rubber sleeve 805 to complete the setting and sealing, the first water outlet hole coincides with the first drainage hole.

[0104] The lower outer sleeve 808 is threaded to the inner wall of the lower end of the first lower connector 809. The lower end of the third central tube is inserted into the inner wall of the upper end of the first lower connector 809. A convex ring is provided on the inner wall of the lower outer sleeve 808. A groove is provided in the corresponding area of ​​the lower outer sleeve 808 by the third central tube 807. A spring body is provided between the third central tube 807 and the lower outer sleeve 808. A first engaging part is provided on the outer wall of the spring body, which sits on the upper end face of the convex ring. A second engaging part is provided on the inner wall of the spring body, and the upper end face of the second engaging part contacts the upper end face of the groove.

[0105] The spring body prevents the type 1 packer 3 from accidentally setting.

[0106] Please see Figures 3 to 5 The type II packer 4 includes a fourth central tube 904, and a second inverted safety part 9, a second anchoring and unblocking part 10, a second sealing and backwashing well part 11, and a support and setting part 12 arranged sequentially on the fourth central tube 904.

[0107] The second inverted safety part 9 includes a second upper connector 901, a second locking block sleeve 902, a second locking block 903, and a second shear pin sleeve 905. The upper inner wall of the fourth central tube 904 is connected to the lower outer wall of the second upper connector 901 by an inverted thread. The second locking block 903 passes through the upper end of the fourth central tube 904 and is inserted into the second upper connector 901. The second shear pin sleeve 905 is fitted on the lower outer wall of the fourth central tube 904 below the second upper connector 901. The second shear pin sleeve 905 is connected to the fourth central tube 904 through a second shear pin. The fourth central tube 904 is provided with a third pressure transmission hole at a corresponding position on the upper end of the second shear pin sleeve 905. The second locking block sleeve 902 is threadedly connected to the outer wall of the second shear pin sleeve 905. The second locking block sleeve 902 covers the second locking block 903. The second locking block sleeve 902 is provided with a second receiving groove on the inner wall above the second locking block 903.

[0108] The second anchoring and unlocking part 10 includes an anchor claw 1001 and a second anchor body 1002. The second anchor body 1002 is fitted onto the fourth central tube 904. The two ends of the anchor claw 1001 are fixed to the outer wall of the second anchor body 1002. The second anchor body 1002 has a second through hole in the area corresponding to the anchor claw 1001. A third piston is provided in the second through hole. A third spring is provided between the third piston and the anchor claw 1001. At least two sets of anchor claw 1001, second through hole, third piston, and third spring are provided. Two second through holes are provided in the area corresponding to the anchor claw 1001. The middle of the anchor claw 1001 is fixed to the outer wall of the second anchor body 1002. The fourth central tube 904 has a pressure groove in the area corresponding to the anchor claw 1001. A fourth pressure transmission hole is provided in the pressure groove.

[0109] The second sealing and backwashing well section 11 includes a water inlet sleeve, an upper retaining ring, and a cone 1104; the lower end of the second anchor 1002 is threadedly connected to the water inlet sleeve on the outer wall; a fourth spring 1101 is provided above the annular space between the water inlet sleeve and the fourth central tube 904; a fourth piston 1102 is provided at the lower end of the fourth spring 1101; the lower end face of the fourth piston 1102 is an outer cone surface; the upper retaining ring is threadedly connected to the lower end of the inner wall of the water inlet sleeve; the upper retaining ring is not in contact with the fourth central tube 904; the upper end face of the upper retaining ring is an inner cone surface; the lower end face of the fourth piston 1102 is in contact with the upper end face of the upper retaining ring; the water inlet sleeve is provided with a second water inlet hole above the upper end face of the upper retaining ring; and the fourth central tube 904 is provided with a fifth pressure transmission hole at the corresponding position above the fourth spring 1101.

[0110] The lower end of the upper retaining ring is threadedly connected to a second rubber sleeve seat. The second rubber sleeve seat does not contact the fourth central tube 904. At least two second rubber sleeves 1103 are fitted on the outer side of the second rubber sleeve seat. A separator ring is provided between every two second rubber sleeves 1103. The cone 1104 is provided on the lower end of the outer wall of the second rubber sleeve seat and can slide relative to the second rubber sleeve seat. An outer cone is provided at the lower end of the cone 1104. The outer cone contacts the fourth central tube 904. A second water outlet is provided above the outer cone of the cone 1104.

[0111] The supporting seat portion 12 includes a limiting shell, a reversing sleeve 1203, and a second lower connector 1204. The limiting shell is fitted onto the fourth central tube 904 and positioned below the cone 1104. The upper end of the limiting shell is provided with at least two slip grooves, and the middle part is provided with at least two straightening grooves. Each slip groove is provided with a slip 1201. The upper end of the slip 1201 is provided with an inner cone, and the outer wall of the inner cone is provided with slip teeth. The lower end of the slip 1201 is fixed in the slip groove. Each straightening groove is provided with a straightening block 1202. The outer walls of the upper and lower ends of the straightening groove protrude inward to prevent the straightening block 1202 from detaching from the limiting shell. A spring sheet is provided between the straightening block and the straightening groove to allow the straightening block to extend out of the limiting shell. The upper and lower ends of the straightening block are provided with inclined surfaces.

[0112] The upper end of the reversing sleeve 1203 is threadedly connected to the lower outer wall of the limiting housing, and the upper inner wall of the second lower connector 1204 is threadedly connected to the lower outer wall of the fourth central tube 904. The inner wall of the reversing sleeve 1203 is provided with a "7"-shaped groove, which is divided into a short groove and a long groove. The upper outer wall of the second lower connector 1204 is provided with a reversing block, which is embedded in the short groove or the long groove. When the reversing block is embedded in the short groove, the second lower connector 1204 and the reversing sleeve 1203 move synchronously. When the reversing block is embedded in the long groove, the second lower connector 1204 and the reversing sleeve 1203 slide relative to each other.

[0113] The reverse thread is a left-hand thread, and the thread is a right-hand thread.

[0114] The anchor teeth 702 and anchor claws 1001 are made of cast iron and can be milled or drilled.

[0115] The first locking block sleeve, the first shear pin sleeve, the second locking block sleeve 902, and the second shear pin sleeve 905 are made of cast iron and can be milled or drilled.

[0116] Example 2:

[0117] Based on Example 1, the present invention provides a method for using a safe inspection and replacement tubing string, comprising the following steps:

[0118] S1. Assemble the tubing string and run it into the well. According to the construction design depth, use tubing of different lengths to assemble compensator 1, water distributor 2, type I packer 3, type II packer 4, and well washing valve 5 and run them into the well to deliver them to the design depth, so that one water distributor corresponds to one injection layer.

[0119] S2, Setting: After reaching the designed depth, first complete the setting of the lower type II packer 4. "Lift up" - "right turn" the tubing string. The second lower connector 1204 reversing block is in the long groove of the "7" shaped groove on the inner wall of the reversing sleeve 1203. Lower the tubing string. At this time, the slip 1201 extends and locks onto the inner wall of the sleeve. Continue to lower the tubing string. The slip 1201 tightens, and the cone 1104 compresses the second rubber sleeve 1103 to achieve setting.

[0120] After the bottom type II packer is set, the tubing continues to be lowered to set the top type I packer. The type I packer will use the bottom type II packer as a support point. At this time, the tubing continues to be lowered. The first lower connector 809 remains fixed. The first inverted safety part 6, the first anchoring release part 7, the third central tube 807, the upper outer sleeve 801, and the upper support body 804 move downward. The upper support body 804 compresses the first rubber sleeve 805 to achieve setting. At this time, the first outlet hole coincides with the first drainage hole.

[0121] S3. Water injection: Open each level of water distributor 2, adjust the water distributor to the appropriate opening according to the injection volume requirements, and inject water into the oil pipe;

[0122] After the oil pipe is pressurized, the oil pipe pressure passes through the gap between the second central pipe 701 and the first anchor body 703, pushes the first piston, and causes the anchor tooth 702 to extend. The oil pipe pressure enters the pressure groove through the fourth pressure transmission hole, pushes the third piston, and causes the anchor claw 1001 to extend.

[0123] The oil pipe pressure passes through the second pressure transmission hole, causing the second piston 803 to sit on the upper support body 804. The oil pipe pressure passes through the fifth pressure transmission hole, causing the fourth piston 1102 to sit on the upper retaining ring, and the backwash channel is closed.

[0124] S4. Backwashing well: After stopping water injection and depressurizing the tubing, backwashing fluid is injected from the annulus of the tubing. The backwashing fluid enters from the first inlet, causing the second piston 803 to push the second spring 802 under the backwashing pressure. The backwashing channel opens, and the backwashing fluid is discharged from the first outlet and passes through the type 1 packer 3.

[0125] The backwash fluid enters from the second inlet, causing the fourth piston 1102 to push the fourth spring 1101 under the backwash pressure, opening the backwash channel and discharging the backwash fluid from the second outlet, passing through the type II packer 4.

[0126] The backwashing fluid enters the tubing through well-washing valve 5 and returns to the surface;

[0127] S5. Unsealing: After the oil pipe is depressurized, the anchor teeth 702 and anchor claws 1001 of the type 1 packer 3 and the type 2 packer 4 are retracted, the tubing is "lifted", the upper support body 804 of the type 1 packer 3 is moved upward, the first rubber sleeve 805 is retracted, and the type 1 packer is unsealed.

[0128] Continue to "lift" the tubing string. The reversing block of the second lower connector 1204 of the type II packer 4 moves from the lower end of the long groove of the reversing sleeve 1203 to the upper end. The slip 1201 is retracted, the cone 1104 is retracted, the second rubber sleeve 1103 loses compression, and the second rubber sleeve 1103 is retracted, thus completing the unsealing of the second packer.

[0129] S6, Release, Drilling and Milling: If the tubing gets stuck later, the tubing can be "pressurized" and "rotated in the forward direction" to release the tubing from the packer. The remaining part in the well can be milled or drilled.

[0130] After the tubing is pressurized, the first shearing sleeve of the packer 3 cuts the first shearing nail 603, which drives the locking block sleeve to move down. The first locking block 602 pops out into the first receiving groove. The first upper connector 601 is disengaged from the first central tube 104 by right rotation and pulled out. The remaining part of the well is milled or drilled using wellbore processing tools.

[0131] After the tubing is pressurized, the second shear pin sleeve 905 of the type II packer cuts off the second shear pin, causing the second locking block sleeve 902 to move down, and the second locking block 903 pops out into the second receiving groove. The second upper connector 901 and the fourth central tube 904 are then disengaged and pulled out. The remaining part of the well is then milled or drilled using wellbore processing tools.

[0132] The shearing pressure of the second shear pin is less than that of the first shear pin 603. When there are at least two first shear pins, the deeper the position, the smaller the shearing pressure.

[0133] 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.

[0134] 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.

[0135] 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.

[0136] 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.

[0137] 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 safety inspection and replacement string, comprising an oil pipe, wherein at least three water distributors are provided on the oil pipe, a packer is provided between every two water distributors, and each water distributor corresponds to a water injection layer, characterized in that, The bottom packer is a Type II packer, and the remaining packers are Type I packers; The type I packer is provided with a first inverted safety part, and the type II packer is provided with a second inverted safety part; The type of packer includes a first inverted safety section, a first anchoring and release section, and a first sealing and backwashing section connected in sequence. The first anchoring release section includes a first anchor body; The first sealing and backwashing section includes an upper outer sleeve, an upper support body, a first rubber sleeve, a lower support body, a third central tube, and a lower outer sleeve; The upper outer sleeve is connected to the first anchor body by a thread, and the upper end of the third central tube is connected to the inner wall of the upper end of the upper outer sleeve by a thread; The outer wall of the upper jacket is provided with a downwardly extending protrusion. A second spring is provided at the upper end of the annular space between the protrusion and the third central tube. 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. A second pressure transmission hole is provided at the corresponding position on the upper end of the second spring in the third central tube. The lower end of the protrusion is threaded to an upper support body, the upper end face of the upper support body is an inner conical surface, and the lower end face of the second piston is in contact with the upper end face of the upper support body. The upper support body does not contact the third central tube, and the protrusion is provided with a first water inlet hole above the upper end face of the upper support body; The lower end inner wall of the upper support body is threadedly connected to a first rubber sleeve seat. The first rubber sleeve seat does not contact the third central tube. At least two first rubber sleeves are fitted on the first rubber sleeve seat. A spacer ring is provided between each two first rubber sleeves. The lower end outer wall of the first rubber sleeve seat is provided with a lower support body. The lower support body can slide relative to the first rubber sleeve seat. The upper end of the lower support body is in contact with the first rubber cylinder. The lower outer wall of the lower support body is threaded with a lower outer sleeve. The lower outer sleeve is provided with a first water outlet hole below the lower support body. The first rubber cylinder seat is provided with a first drainage hole at the corresponding position of the lower support body. When the lower support body moves upward to squeeze the first rubber cylinder to complete the setting seal, the first water outlet hole and the first drainage hole coincide. The lower end of the outer sleeve is threaded to the inner wall of the lower end of the first lower connector, and the lower end of the third central tube is inserted into the inner wall of the upper end of the first lower connector. The inner wall of the lower outer sleeve is provided with a protruding ring, and the third central tube is provided with a groove in the corresponding area of ​​the lower outer sleeve; A spring body is provided between the third central tube and the lower outer sleeve. The outer wall of the spring body 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.

2. The safety inspection and replacement string according to claim 1, characterized in that, A well-washing valve is installed at the bottom of the tubing, and a compensator is installed above the water distributor at the top of the tubing.

3. The safety inspection and replacement string according to claim 2, characterized in that, The first inverted safety component includes a first upper connector, a first 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 first upper connector by a reverse thread; the first locking block passes through the upper end of the first central tube and is inserted into the first upper connector; The first central tube is fitted with a first shear pin sleeve on its outer wall below the first upper connector; The first shear pin sleeve is connected to the first central tube via the first shear pin, and the first central tube is provided with a first pressure transmission hole at the corresponding position on the upper end of the first shear pin sleeve; The outer wall of the first shear pin sleeve is connected to a first locking block sleeve by threads. The first locking block sleeve covers the first locking block, and the inner wall of the first locking block sleeve above the first locking block is provided with a first receiving groove.

4. The safety inspection and replacement string according to claim 3, characterized in that, The first anchoring and unblocking section also includes a second central tube and anchor teeth; The upper end of the first anchor body is connected to the lower end of the first central tube by a thread, and the two ends of the anchor teeth are fixed to the outer wall of the first anchor body; The first anchor body has a first through hole in the area corresponding to the anchor tooth, and the second central tube is fitted into the first anchor body; A first piston is provided inside the first through hole, and a first spring is provided between the first piston and the anchor tooth; The anchor tooth, the first through hole, the first piston, and the first spring are provided in at least two sets.

5. The safety inspection and replacement string according to claim 4, characterized in that, The type II packer includes a fourth central tube, and a second inverted safety part, a second anchoring and release part, a second sealing and backwashing part, and a support and setting part, which are sequentially arranged on the fourth central tube.

6. The safety inspection and replacement string according to claim 5, characterized in that, The second inverted safety part includes a second upper connector, a second locking block sleeve, a second locking block, and a second shear pin sleeve; The upper inner wall of the fourth central tube is connected to the lower outer wall of the second upper connector by a reverse thread, and the second locking block passes through the upper end of the fourth central tube and is inserted into the second upper connector. The fourth central tube is fitted with a second shear pin sleeve on the outer wall below the second upper connector. The second shear pin sleeve is connected to the fourth central tube through the second shear pin. The fourth central tube is provided with a third pressure transmission hole at the corresponding position on the upper end of the second shear pin sleeve. The outer wall of the second shear pin sleeve is threadedly connected to a second locking block sleeve, the second locking block sleeve covers the second locking block, and the inner wall of the second locking block sleeve above the second locking block is provided with a second receiving groove.

7. A safety inspection and replacement string according to claim 6, characterized in that, The second anchoring release section includes anchor claws and a second anchor body; The second anchor body is fitted onto the fourth central tube, and the two ends of the anchor claw are fixed to the outer wall of the second anchor body. The second anchor body has a second through hole in the area corresponding to the anchor claw. A third piston is installed in the second through hole, and a third spring is installed between the third piston and the anchor claw. At least two sets of anchor claw, second through hole, third piston, and third spring are provided. The fourth central tube is provided with a pressure groove in the area corresponding to the anchor claw, and a fourth pressure transmission hole is provided in the pressure groove.

8. A safety inspection and replacement string according to claim 7, characterized in that, Two second through holes are opened in the corresponding area of ​​the anchor claw, and the middle of the anchor claw is also fixed to the outer wall of the second anchor body.

9. A safety inspection and replacement string according to claim 8, characterized in that, The second sealing and backwashing well section includes an inlet sleeve, an upper retaining ring, and a cone. The lower end of the second anchor body is threadedly connected to a water inlet sleeve. A fourth spring is provided above the annular space between the water inlet sleeve and the fourth central tube. A fourth piston is provided at the lower end of the fourth spring. The lower end face of the fourth piston is an outer conical surface. The upper retaining ring is threaded to the lower inner wall of the water inlet sleeve. The upper retaining ring is not in contact with the fourth central tube. The upper end face of the upper retaining ring is an inner conical surface. The lower end face of the fourth piston is in contact with the upper end face of the upper retaining ring. The water inlet sleeve is provided with a second water inlet hole above the upper end face of the upper baffle ring, and the fourth central tube is provided with a fifth pressure transmission hole at the corresponding position on the upper end of the fourth spring; The lower end of the upper retaining ring is threadedly connected to a second rubber sleeve seat. The second rubber sleeve seat does not contact the fourth central tube. At least two second rubber sleeves are fitted on the outer side of the second rubber sleeve seat, and a separator ring is provided between each two second rubber sleeves. The cone is disposed on the lower outer wall of the second rubber sleeve seat and can slide relative to the second rubber sleeve seat. An outer cone is disposed at the lower end of the cone and the outer cone is in contact with the fourth central tube. A second water outlet is disposed above the outer cone.

10. A safety inspection and replacement string according to claim 9, characterized in that, The supporting seat portion includes a limiting shell; The limiting housing is fitted onto the fourth central tube and positioned below the cone. The upper end of the limiting housing is provided with at least two locking grooves, and the middle part is provided with at least two straightening grooves. Each slip groove contains a slip, the upper end of which has an inner cone, the outer wall of which has slip teeth, and the lower end of which is fixed in the slip groove. Each straightening groove is provided with a straightening block. The outer walls of the upper and lower ends of the straightening groove protrude inward to prevent the straightening block from detaching from the limiting shell. A spring sheet is provided between the straightening block and the straightening groove. The upper and lower ends of the straightening block are provided with inclined surfaces.

11. A safety inspection and replacement string according to claim 10, characterized in that, The supporting seat also includes a reversing sleeve and a second lower connector; The upper end of the reversing sleeve is threaded to the lower outer wall of the limiting housing, the upper inner wall of the second lower connector is threaded to the lower outer wall of the fourth central tube, and the inner wall of the reversing sleeve is provided with a "7" shaped groove, which is divided into a short groove and a long groove. The upper outer wall of the second lower connector is provided with a reversing block. The reversing block is embedded in a short slot or a long slot. When the reversing block is embedded in the short slot, the second lower connector and the reversing sleeve move synchronously. When the reversing block is embedded in the long slot, the second lower connector and the reversing sleeve can slide relative to each other.

12. A safety inspection and replacement string according to claim 3 or 6, characterized in that, The reverse thread is a left-hand thread.

13. A safety inspection and replacement string according to claim 4, characterized in that, The first locking block sleeve and the first shear pin sleeve are made of cast iron and can be milled or drilled. The anchor teeth are made of cast iron and can be milled or drilled.

14. A safety inspection and replacement string according to claim 7 or 8, characterized in that, The second locking block sleeve and the second shear pin sleeve are made of cast iron and can be milled or drilled. The anchor claws are made of cast iron and can be milled or drilled.

15. A method for using the safety inspection and replacement tubing string as described in claim 11, characterized in that, Includes the following steps: S1. Assemble the tubing string and run it into the well. According to the construction design depth, use tubing of different lengths to assemble the compensator, water distributor, type I packer, type II packer, and well washing valve and run them into the well to deliver them to the design depth, so that one water distributor corresponds to one injection layer. S2, Setting: "Lift up" - "Right turn" the tubing string to set the Type II packer, then continue "Lower down" the tubing string to set the Type I packer. At this time, the first outlet hole coincides with the first drain hole. S3. Water injection: Open each level of water distributor, adjust the water distributor to the appropriate opening according to the injection volume requirements, and inject water into the oil pipe; after the oil pipe is pressurized, the anchor teeth and anchor claws will extend. S4. Backwashing well: After stopping water injection and depressurizing the tubing, backwashing fluid is injected from the annulus of the casing and tubing. The backwashing fluid passes through the type I packer, the type II packer, and the well-washing valve, and then enters the tubing to return to the surface. S5. Unsealing: After the tubing is depressurized, the anchor teeth and anchor claws are retrieved, the tubing string is "lifted up", and the Type I packer is unsealed; the tubing string is "lifted up" again, and the Type II packer is unsealed. S6, Release and Milling: If the tubing gets stuck, use tubing "pressure boost" - "forward rotation" to release the tubing from the packer in reverse for safety. The remaining part in the well is then milled or drilled.

16. The method of use according to claim 15, characterized in that, The process of setting the seal is as follows: After reaching the design depth, the lower type II packer is first set. The tubing is then lifted and rotated to the right. The reversing block of the second lower connector is positioned in the long groove of the "7"-shaped groove on the inner wall of the reversing sleeve. The tubing is then lowered. At this point, the slips extend and engage with the inner wall of the sleeve. The tubing is then lowered further, the slips tighten, and the cone compresses the second rubber sleeve, thus achieving the setting seal. After the bottom Type II packer is set, the tubing continues to be lowered to set the top Type I packer. The Type I packer will use the bottom Type II packer as a support point. At this time, the tubing continues to be lowered. The first lower connector remains fixed, while the first inverted safety part, the first anchor release part, the third central tube, the upper outer sleeve, and the upper support body move downwards. The upper support body compresses the first rubber sleeve to achieve setting. At this time, the first outlet hole coincides with the first drainage hole.

17. The method of use according to claim 15, characterized in that, When injecting water, open each level of water distributor, adjust the water distributor to the appropriate opening degree according to the injection volume requirements, and inject water into the oil pipe; After the oil pipe is pressurized, the oil pipe pressure passes through the gap between the second central pipe and the first anchor body, pushes the first piston, and causes the anchor teeth to extend. The oil pipe pressure enters the pressure groove through the fourth pressure transmission hole, pushes the third piston, and causes the anchor claws to extend. The oil pipe pressure passes through the second pressure transmission hole, causing the second piston to sit on the upper support body. The oil pipe pressure passes through the fifth pressure transmission hole, causing the fourth piston to sit on the upper retaining ring, and the backwash channel is closed.

18. The method of use according to claim 15, characterized in that, The process of backwashing fluid returning to the surface through Type I and Type II packers is as follows: After stopping water injection and depressurizing the tubing, backwashing fluid is injected from the annulus of the casing. The backwashing fluid enters from the first inlet hole, causing the second piston to push the second spring to move under the backwashing pressure. The first backwashing channel opens, and the backwashing fluid is discharged from the first outlet hole and passes through a type 1 packer. The backwash fluid enters through the second inlet hole, causing the fourth piston to push the fourth spring under the backwash pressure. The second backwash channel opens, and the backwash fluid is discharged through the second outlet hole, passing through the type II packer. The backwash fluid enters the tubing through the backwash valve and returns to the surface.

19. The method of use according to claim 15, characterized in that, During unsealing, after the oil pipe is depressurized, the anchor teeth of the Type I packer and the anchor claws of the Type II packer are retracted, the tubing string is "lifted", which drives the upper support of the Type I packer to move upward, and the first rubber sleeve is retracted, thus realizing the unsealing of the Type I packer; Continue to "lift" the tubing string. The reversing block of the second lower connector of the type II packer moves from the lower end of the long groove of the reversing sleeve to the upper end. The slip is retracted, the cone is retracted, the second rubber sleeve loses compression, and the second rubber sleeve is retracted, completing the unsealing of the type II packer.

20. The method of use according to claim 15, characterized in that, The S6, drop-out, and drilling / milling processes are divided into two cases; Type 1 packer jammed: The tubing is raised to the first shear pin shearing pressure, the first shear pin sleeve of the Type 1 packer shears the first shear pin, which drives the first locking block sleeve to move down, the first locking block pops out into the first receiving groove, the first upper connector and the first central tube are disengaged and pulled out by right-hand rotation, and the remaining part of the well is milled or drilled using wellbore processing tools. Type II packer jammed: When the tubing is raised to the shearing pressure of the second shear pin, the second shear pin sleeve of the Type II packer shears the second shear pin, which drives the second locking block sleeve to move down. The second locking block pops out into the second receiving groove, and the second upper connector is disengaged from the fourth central tube by right-hand rotation and pulled out. The remaining part of the well is then milled or drilled using wellbore processing tools. The shearing pressure of the second shear pin is less than that of the first shear pin. When there are at least two first shear pins, the deeper the position, the smaller the shearing pressure.

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