Packer, integrated tubular column and oil well layering operation method

Abstract

The invention discloses a packer, an integrated tubular column and an oil well layering operation method, and relates to the technical field of oil exploitation equipment.The packer is provided with a central pipe, an anchoring mechanism and a hydraulic pressure building unlocking mechanism, in the deblocking operation process, the tubular column does not need to be lifted, deblocking can be triggered only by putting a second pressure building ball from the upper portion of the tubular column and building pressure, and the deblocking efficiency is improved. Therefore, the packer at the specific position on the tubular column can be independently unsealed, all the packers above the position do not need to be unsealed in sequence, the operation difficulty of unsealing operation is reduced, the operation procedures are reduced, the operation period is shortened, meanwhile, the safety risks such as tubular column jamming and sleeve damage possibly caused by lifting of the tubular column are avoided, and the safety of the tubular column is improved. And the safety and the efficiency of underground operation are improved.

Description

Technical Field

[0001] This invention relates to the field of oil extraction equipment technology, and in particular to a packer, an integrated tubing string, and a method for layered well operations. Background Technology

[0002] Packers are commonly used equipment in oil well operations for well washing, stratified water injection, and stratified pumping. In use, packers are usually connected with other functional tubing sections and tubing to form a string that runs from the drilled well to the downhole. After the packer has been set, the corresponding downhole operations are performed.

[0003] When using tubing strings for downhole operations in oil and gas wells, packers are often required. In existing technology, common packer setting operations typically involve dropping a ball into the tubing string, then pressurizing it. The hydraulic cylinder mounted on the packer moves under this pressure, causing the rubber sleeve and slips to extend and engage with the inner wall of the casing lowered into the well during drilling. Unsealing is usually accomplished by lifting the tubing string. While this method achieves both setting and unsealing, in practice, because multiple packers are often installed on the tubing string, unsealing a specific packer requires sequentially unsealing all packers above that location. This makes the unsealing process not only difficult but also increases safety risks. Summary of the Invention

[0004] The main objective of this invention is to propose a packer, an integrated tubing string, and a method for layered well operations. This invention aims to solve the technical problem that in the actual operation process of existing technologies, since multiple packers are often installed on the tubing string, if it is necessary to unseal a packer at a specific location, all packers above that location need to be unsealed sequentially. This makes the entire unsealing process not only difficult but also increases safety risks.

[0005] To achieve the above objectives, in a first aspect, the present invention provides a packer comprising: The central tube includes an integrally formed mounting section and a working section. The working section has multiple rings of jet holes distributed at intervals along the length of the central tube and initially in a blocked state. One ring of jet holes is located close to the mounting section. The end of the mounting section away from the working section is interference-fitted with an abutment seat. A hydraulic cylinder liner is installed at the end of the working section away from the mounting section. A first pressure-blocking ball seat is installed in the cavity of the end of the mounting section away from the working section. A second pressure-blocking ball seat is installed at the junction of the mounting section and the working section. An anchoring mechanism, wherein the anchoring mechanism is sleeved on the outer periphery of the mounting section, with one end abutting against the abutment seat and the other end extending toward the working section; and, A hydraulic pressure-locking unlocking mechanism is installed in the working section. The hydraulic pressure-locking unlocking mechanism includes an outer shell and a multi-stage hydraulic pressure-locking unlocking component. The outer shell has a bellows-like structure and its two ends are respectively connected to the hydraulic cylinder liner and the anchoring mechanism. The multi-stage hydraulic pressure-locking unlocking component is sleeved on the outer periphery of the working section and one end is connected to the anchoring mechanism. The outer shell is sleeved on the outer periphery of the multi-stage hydraulic pressure-locking unlocking component. A one-way valve that can discharge gas inside the outer shell is provided on the outer shell. Specifically, when the first pressure-blocking ball seat is in the first pressure-blocking state, the hydraulic cylinder liner can push the hydraulic pressure-blocking unlocking mechanism to move towards the abutment seat, causing the anchoring mechanism to switch from the release state to the anchoring state; when the second pressure-blocking ball seat is in the second pressure-blocking state, the liquid column in the central tube opens the jet hole near the installation section and enters the multi-stage hydraulic pressure-blocking unlocking component, releasing pressure step by step, driving the anchoring mechanism to move towards the hydraulic cylinder liner and switch from the anchoring state to the release state.

[0006] The technical solution of this invention involves setting a first pressure-blocking ball seat and a second pressure-blocking ball seat within the cavity of the central tube, and setting multiple ring-shaped jet holes on the working section and a multi-stage hydraulic pressure-blocking unlocking component on the outer periphery of the working section. This allows the sealing and unsealing operations to be triggered independently by inserting different pressure-blocking balls. During the sealing stage, when the first pressure-blocking ball seat is in the first pressure-blocking state, the hydraulic cylinder liner pushes the hydraulic pressure-blocking unlocking mechanism towards the contact seat, causing the anchoring mechanism to switch from the release state to the anchoring state. During the unsealing stage, when the second pressure-blocking ball seat is in the second pressure-blocking state, the liquid column enters the multi-stage hydraulic pressure-blocking unlocking component through the jet holes and releases pressure step by step, driving the anchoring mechanism to move towards the hydraulic cylinder liner and switch from the anchoring state to the release state. Compared to existing technologies that use tubing string lifting for unsealing, the packer unsealing operation in this application does not require lifting the tubing string. Unsealing is triggered simply by inserting a second pressure-pressurizing ball from above the tubing string and applying pressure. This allows for individual unsealing of packers at specific locations on the tubing string, eliminating the need to sequentially unseal all packers above that location. This reduces the operational difficulty, streamlines the process, and shortens the operation cycle. It also avoids safety risks such as tubing jamming and casing damage that may occur when lifting the tubing string, improving the safety and efficiency of downhole operations. Furthermore, the outer shell adopts a corrugated pipe-like structure, allowing it to adaptively expand and contract axially during setting and unsealing. Combined with a one-way valve to discharge internal gas, this ensures smooth movement and structural reliability of the hydraulic pressure-pressurizing unlocking mechanism during setting and unsealing. The central tube uses an integrated structure for the installation and working sections, avoiding sealing failures and insufficient strength that may result from separate connections, ensuring the long-term reliability of the packer in high-temperature and high-pressure downhole environments. Attached Figure Description

[0007] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0008] Figure 1 This is a schematic diagram of the overall structure of the packer provided by the present invention; Figure 2 for Figure 1 A schematic diagram of the internal structure of the packer in the example; Figure 3 for Figure 2 A schematic diagram of the internal structure of the packer with the outer casing removed, as shown in the example; Figure 4 for Figure 1A schematic diagram of the internal structure of the multi-stage hydraulic pressure-locking unlocking component in the example, in its assembled state; Figure 5 for Figure 1 A schematic diagram of the internal structure of the packer removal anchoring mechanism in the example; Figure 6 for Figure 1 A schematic diagram of the internal structure of the hydraulic pressure-locking mechanism shown in the example; Figure 7 for Figure 6 A schematic diagram of the structure of the first ratchet sleeve and the first pressure unlocking component in the example; Figure 8 for Figure 6 A schematic diagram of the internal structure of the second ratchet sleeve in the example; Figure 9 for Figure 6 A schematic diagram of the third ratchet sleeve in the example; Figure 10 for Figure 1 A schematic diagram of the hydraulic pressure-locking mechanism assembled with the anchoring mechanism in the example; Figure 11 for Figure 10 A detailed structural diagram of the anchoring mechanism in the example; Figure 12 for Figure 10 Another perspective of the detailed structure of the anchoring mechanism in the example; Figure 13 for Figure 12 A detailed structural diagram of the pressure transmission sleeve in the example; Figure 14 This is a schematic diagram of the structure of one unit of the integrated tubular column as an example of the present invention; Figure 15 This is a flowchart illustrating an oil well stratification operation method as an example of the present invention.

[0009] Explanation of icon numbers: 100. Central tube; 110. Mounting section; 120. Working section; 130. Jet orifice; 140. Abutment seat; 150. One-way valve; 200. Hydraulic cylinder liner; 210. First pressure-locking ball seat; 220. Second pressure-locking ball seat; 300. Anchoring mechanism; 400. Hydraulic pressure-locking unlocking mechanism; 410. Housing; 420. Multi-stage hydraulic pressure-locking unlocking component; 421. First ratchet sleeve; 422. First pressure-locking unlocking assembly; 423. First piston pressure-locking chamber; 424. Second pressure-locking unlocking assembly; 425. First sleeve; 426. First shear pin; 427. First ratchet ring; 428. First ratchet tooth ring; 429. First partition post; 430. First ratchet tooth groove; 431. First unlocking ring; 432. First piston ring; 433. First connecting ring; 434. First unlocking rod; 435. First abutment ring ; 436. Second shear pin; 437. Second ratchet sleeve; 438. Third shear pin; 439. Second sleeve; 440. Second ratchet ring; 441. Second ratchet tooth ring; 442. Second separator post; 443. Second ratchet tooth groove; 444. Second unlocking ring; 445. Second piston ring; 446. Second connecting ring; 447. Second unlocking lever; 448. Second abutment ring; 449. Fourth shear pin; 45 0. Third ratchet sleeve; 451. Fifth shear pin; 452. Third sleeve; 453. Third ratchet ring; 10. Packer; 20. Tubing string module; 21. Tubing section; 22. Leakage prevention well washing joint; 23. Fracturing sliding sleeve; 310. Connecting seat; 320. Elastic reset element; 330. Pressure transmission sleeve; 340. Setting and anchoring assembly; 350. Rubber sleeve; 360. Anchor block; 454. Liquid flow channel.

[0010] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0011] 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 a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0012] It should be noted that if the embodiments of the present invention involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a specific posture. If the specific posture changes, the directional indicators will also change accordingly.

[0013] Furthermore, if the embodiments of this invention involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the use of "and / or" or "and / or" throughout the text includes three parallel solutions. For example, "A and / or B" includes solution A, solution B, or a solution where both A and B are satisfied simultaneously. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0014] When using tubing strings for downhole operations in oil and gas wells, packers are often required. In existing technology, common packer setting operations typically involve dropping a ball into the tubing string, then pressurizing it. The hydraulic cylinder mounted on the packer moves under this pressure, causing the rubber sleeve and slips to extend and engage with the inner wall of the casing lowered into the well during drilling. Unsealing is usually accomplished by lifting the tubing string. While this method achieves both setting and unsealing, in practice, because multiple packers are often installed on the tubing string, unsealing a specific packer requires sequentially unsealing all packers above that location. This makes the unsealing process not only difficult but also increases safety risks.

[0015] This invention proposes a packer, an integrated tubing string, and a method for layered well operations.

[0016] Please see Figures 1 to 15For ease of understanding, this packer 10 includes a central tube 100, an anchoring mechanism 300, and a hydraulic pressure-locking mechanism 400. The central tube 100 includes an integrally formed mounting section 110 and a working section 120. The working section 120 has multiple rings of spaced jet holes 130 distributed along the length of the central tube 100, which are initially in a blocked state. One ring of jet holes 130 is located close to the mounting section 110. The end of the mounting section 110 away from the working section 120 is interference-fitted with an abutment seat 140. A hydraulic cylinder liner 200 is installed at the end of the working section 120 away from the installation section 110. A first pressure-holding ball seat 210 is installed in the cavity of the end of the installation section 110 away from the working section 120. A second pressure-holding ball seat 220 is installed at the junction of the installation section 110 and the working section 120. An anchoring mechanism 300 is sleeved on the outer periphery of the installation section 110, with one end abutting against the abutment seat 140 and the other end extending toward the working section 120. A hydraulic pressure-holding unlocking mechanism 400 is installed in the working section 120. The hydraulic pressure-holding unlocking mechanism 400 includes an outer... The housing 410 and the multi-stage hydraulic pressure-locking unlocking component 420 are included. The housing 410 has a bellows-like structure and its two ends are respectively connected to the hydraulic cylinder liner 200 and the anchoring mechanism 300. The multi-stage hydraulic pressure-locking unlocking component 420 is sleeved on the outer periphery of the working section 120 and one end is connected to the anchoring mechanism 300. The housing 410 is sleeved on the outer periphery of the multi-stage hydraulic pressure-locking unlocking component. A one-way valve 150 is provided on the housing 410 to discharge the gas inside the housing 410. The hydraulic cylinder liner 200 can be positioned at the first pressure-locking ball seat 210. In the first pressurized state, the hydraulic pressurized unlocking mechanism 400 is pushed to move towards the abutment seat 140, causing the anchoring mechanism 300 to switch from the release state to the anchoring state. When the second pressurized ball seat 220 is in the second pressurized state, the multi-stage hydraulic pressurized unlocking component 420 can be opened by the liquid column in the central tube 100, which is close to the jet hole 130 of the installation section 110, and enter the multi-stage hydraulic pressurized unlocking component to release the pressure step by step, thereby driving the anchoring mechanism 300 to move towards the hydraulic cylinder liner 200 and switch from the anchoring state to the release state.

[0017] Specifically, the installation section 110 and the working section 120 are distributed sequentially along the length of the central tube 100. The integrally formed structure ensures that there are no connecting seams between the installation section 110 and the working section 120, thereby guaranteeing the structural strength and sealing reliability of the central tube 100 in the downhole high-pressure environment and avoiding the risk of leakage or breakage caused by separate connections.

[0018] A preset distance is maintained between adjacent annular jet holes 130 on the working section 120. Each annular jet hole 130 is initially in a blocked state. That is, during the packer 10 running into the well and setting operation, the jet holes 130 are blocked by the sealing components and do not communicate with the lumen of the central tube 100, thereby ensuring the hydraulic integrity within the lumen of the central tube 100. One annular jet hole 130 is located close to the installation section 110. This annular jet hole 130 serves as the hydraulic channel for the first stage of pressure release during subsequent unsealing operations. Its proximity to the installation section 110 facilitates the initial application of hydraulic column pressure to the multi-stage hydraulic pressure release component 420 corresponding to this annular jet hole 130, thereby achieving the initial triggering of step-by-step unlocking.

[0019] The abutment seat 140 is fixedly installed at the end of the installation section 110 by an interference fit. The interference fit ensures that a tight radial clamping force is formed between the abutment seat 140 and the installation section 110. Under downhole vibration and hydraulic shock conditions, the abutment seat 140 will not experience axial movement or loosening, thus providing a stable axial abutment reference surface for the anchoring mechanism 300. A hydraulic cylinder liner 200 is installed at the end of the working section 120 away from the installation section 110. The hydraulic cylinder liner 200 is sleeved on the end of the working section 120 and forms a sealed fit with the working section 120. The hydraulic cylinder liner 200 can slide along the axial direction of the central tube 100 under the action of hydraulic pressure in the cavity, thereby converting the hydraulic pressure into an axial thrust that drives the hydraulic pressure release mechanism 400 to move.

[0020] During the setting operation, the first pressure-retaining ball is dropped from above the tubing string. The first pressure-retaining ball falls along the tubing cavity and settles on the first pressure-retaining ball seat 210. The first pressure-retaining ball and the first pressure-retaining ball seat 210 cooperate to form a seal. At this time, the space above the first pressure-retaining ball seat 210 in the tubing cavity is blocked. Liquid continues to be injected into the tubing string and pressurized, increasing the hydraulic pressure in the tubing cavity. The first pressure-retaining ball seat 210 is then in the first pressure-retaining state. A second pressure-retaining ball seat 220 is installed at the junction of the installation section 110 and the working section 120, located within the tubing cavity at the junction of the installation section 110 and the working section 120. During the unsealing operation, the second pressure-retaining ball is dropped from above the tubing. The second pressure-retaining ball falls down along the tubing and sits on the second pressure-retaining ball seat 220. The second pressure-retaining ball and the second pressure-retaining ball seat 220 cooperate to form a seal. At this time, the space above the second pressure-retaining ball seat 220 in the tubing is blocked. Liquid continues to be injected into the tubing and pressurized. The hydraulic pressure in the tubing increases, and the second pressure-retaining ball seat 220 is in the second pressure-retaining state.

[0021] To further clarify, the diameter of the first pressure-locking ball seat 210 is smaller than that of the second pressure-locking ball seat 220. During the setting operation, the smaller-diameter first pressure-locking ball is first placed on the first pressure-locking ball seat 210 to complete the setting. After setting, the first pressure-locking ball on the first pressure-locking ball seat 210 is hydraulically opened or dissolved and released. During the subsequent unsealing operation, the larger-diameter second pressure-locking ball is placed on the second pressure-locking ball seat 220 to trigger the unsealing. Of course, the operators can also choose the relationship between the diameters of the first pressure-locking ball seat 210 and the second pressure-locking ball seat 220 and the corresponding ball placement order according to the actual downhole operating conditions.

[0022] It can be further explained that the anchoring mechanism 300 includes a connecting seat 310, an elastic reset member 320, a pressure transmission sleeve 330, and a setting and anchoring assembly 340.

[0023] The connecting seat 310 is slidably fitted onto the outer periphery of the mounting section 110, maintaining a sliding fit between the connecting seat 310 and the mounting section 110 in the axial direction. This means the connecting seat 310 can reciprocate along the outer wall of the mounting section 110 in the axial direction without disengaging. The connecting seat 310 is connected to the multi-stage hydraulic pressure-locking unlocking component 420 in a fixed connection, allowing the axial movement of the multi-stage hydraulic pressure-locking unlocking component 420 to be transmitted to other components of the anchoring mechanism 300 via the connecting seat 310. A mounting position is formed at the end of the connecting seat 310 away from the multi-stage hydraulic pressure-locking unlocking component 420. This mounting position provides a mounting reference for one end of the elastic reset component 320, through which the elastic reset component 320 is fixedly connected to the connecting seat 310.

[0024] The elastic reset component 320 is a structural component with elastic recovery capability, and can be a spring bar, coil spring, leaf spring, or other elastic element. In the initial state, the elastic reset component 320 is in its natural length state, with one end connected to the mounting position of the connecting seat 310 and the other end connected to the setting and anchoring assembly 340. When the anchoring mechanism 300 transitions from the unlocked state to the anchored state, the connecting seat 310 moves towards the abutment seat 140 under the push of the hydraulic cylinder liner 200, compressing the elastic reset component 320 and shortening its axial length, accumulating elastic potential energy inside the elastic reset component 320. When the anchoring mechanism 300 transitions from the anchored state to the unlocked state, the elastic reset component 320 releases the accumulated elastic potential energy, returning to its natural length state. Its restoring force drives the setting and anchoring assembly 340 to move towards the working section 120, realizing the unsealing action.

[0025] One end of the pressure transmission sleeve 330 is fixedly connected to the connecting seat 310, so that the axial movement of the connecting seat 310 is transmitted to the setting and anchoring assembly 340 through the pressure transmission sleeve 330; the other end of the pressure transmission sleeve 330 is in sliding fit with the abutment seat 140, that is, the pressure transmission sleeve 330 can slide relative to the abutment seat 140 in the axial direction along the outer wall surface of the abutment seat 140. The pressure transmission sleeve 330 has a cylindrical structure, and its outer wall surface forms an annular space with the mounting section 110, in which the setting and anchoring assembly 340 is installed. The pressure transmission sleeve 330 is extensible in the axial direction. When the connecting seat 310 moves toward the abutment seat 140, the pressure transmission sleeve 330 is compressed, its axial length is shortened, and the setting and anchoring assembly 340 moves toward the abutment seat 140 accordingly. When the connecting seat 310 moves toward the working section 120, the pressure transmission sleeve 330 is extended, its axial length is increased, and the setting and anchoring assembly 340 moves toward the working section 120 accordingly.

[0026] In one embodiment, a plurality of mounting holes are formed at the mounting position, and the plurality of mounting holes are distributed circumferentially at intervals on the connecting seat 310. The number of elastic reset members 320 is the same as that of the mounting holes and they are arranged in a one-to-one correspondence. The pressure transmission sleeve 330 is an integrally formed structure, and an array of folded grooves are formed on the pressure transmission sleeve 330.

[0027] In one specific embodiment, folding grooves are arranged around the circumference of the pressure transmission sleeve 330, and multiple folding grooves are arranged at equal intervals along the axial direction of the pressure transmission sleeve 330 to form an array structure of circumferential annular grooves. When the pressure transmission sleeve 330 is subjected to axial compressive force, the wall section between two adjacent circumferential annular grooves bulges outward in the radial direction and folds, and the axial length of the pressure transmission sleeve 330 gradually shortens, realizing compression folding.

[0028] In one embodiment, the pressure transmission sleeve 330 includes an extrusion deformation zone and an engagement zone connected in sequence. The setting and anchoring assembly 340 includes a rubber sleeve 350 and a plurality of anchor blocks 360.

[0029] In this embodiment, the sealing and anchoring functions are simultaneously achieved during the setting stage through the coordinated operation of the rubber sleeve 350 and multiple anchor blocks 360. The rubber sleeve 350 is fitted around the outer periphery of the extrusion deformation zone and extends out and fits against the inner wall of the casing when the pressure transmission sleeve 330 is folded and extruded, achieving an elastic seal. The multiple anchor blocks 360 are arranged in a circumferential array in the engagement zone and extend radially and engage with the inner wall of the casing when the pressure transmission sleeve 330 contracts and abuts against the casing wall, achieving anchoring and positioning. The sealing function of the rubber sleeve 350 and the anchoring function of the anchor blocks 360 are independent yet complementary. The rubber sleeve 350 provides sealing and isolation, while the anchor blocks 360 provide axial fixation. Together, they ensure the reliability of the packer 10's setting in the well. During the unsealing phase, the restoring force of the elastic reset component 320 causes the setting and anchoring assembly 340 to retract towards the working section 120. Simultaneously, the rubber sleeve 350 and the anchoring block 360 retract radially, disengaging from the inner wall of the casing. The seal and anchoring are released simultaneously, and the packer 10 is unsealed. Compared to the existing unsealing method that uses tubing string lifting, this application uses a hydraulic pressure-based triggering mechanism to unlock the multi-stage hydraulic pressure-locking component 420 step-by-step. The elastic reset component 320 releases its elastic potential energy, causing the setting and anchoring assembly 340 to retract. Unsealing can be completed without lifting the tubing string, reducing the operational difficulty and steps involved in the unsealing operation. It also avoids safety risks such as tubing string jamming and casing damage that may occur when lifting the tubing string, thus improving the safety and efficiency of downhole operations.

[0030] More specifically, the outer casing 410 has a bellows-like structure, meaning that the outer wall surface of the outer casing 410 undulates in a wave-like pattern along the axial direction, forming alternating crests and troughs. This bellows-like structure gives the outer casing 410 axial flexibility. When the outer casing 410 is subjected to axial compressive force, the distance between the crests and troughs decreases, and the axial length of the outer casing 410 shortens; when the outer casing 410 is subjected to axial tensile force, the distance between the crests and troughs increases, and the axial length of the outer casing 410 lengthens. The two ends of the outer casing 410 are respectively connected to the hydraulic cylinder liner 200 and the anchoring mechanism 300, that is, one end of the outer casing 410 is fixedly connected to the hydraulic cylinder liner 200, and the other end is fixedly connected to the anchoring mechanism 300, thus forming a closed axial force transmission path between the outer casing 410, the hydraulic cylinder liner 200, and the anchoring mechanism 300.

[0031] A one-way valve 150 is provided on the outer casing 410. The one-way valve 150 is oriented from the inside of the outer casing 410 to the outside of the outer casing 410. That is, the one-way valve 150 only allows gas inside the outer casing 410 to be discharged to the outside of the outer casing 410, but does not allow fluid outside the outer casing 410 to enter the inside of the outer casing 410. During the setting operation, the hydraulic cylinder liner 200 pushes the outer casing 410 towards the abutment seat 140. The bellows-like structure of the outer casing 410 is compressed in the axial direction, and the volume of the annular space inside the outer casing 410 decreases. The gas in the annular space is compressed and discharged to the outside of the outer casing 410 through the one-way valve 150, thereby avoiding the back pressure generated by the accumulation of gas inside the outer casing 410 from hindering the compression movement of the outer casing 410 and ensuring the smooth progress of the setting operation. Meanwhile, due to the one-way conduction characteristic of the check valve 150, the well fluid outside the housing 410 cannot enter the housing 410 through the check valve 150, thereby ensuring a clean and waterless environment inside the housing 410 and preventing solid particles or corrosive media in the well fluid from damaging the multi-stage hydraulic pressure relief unlocking component 420.

[0032] During the setting stage, the first pressure ball is inserted from above the tubing string. The first pressure ball sits on the first pressure ball seat 210 to form a seal. Liquid is injected into the tubing string and pressurized. The first pressure ball seat 210 is in the first pressure-pressurized state. The hydraulic pressure between the first pressure ball seat 210 and the hydraulic cylinder liner 200 in the tubing rises. Under the action of hydraulic pressure, the hydraulic cylinder liner 200 slides along the axial direction of the central tube 100 toward the abutment seat 140. The hydraulic cylinder liner 200 transmits the axial thrust to the anchoring mechanism 300 through the outer shell 410. One end of the anchoring mechanism 300 is limited by the abutment seat 140. The axial thrust causes the slips of the anchoring mechanism 300 to expand radially and engage with the inner wall of the casing. The rubber sleeve expands radially and fits tightly against the inner wall of the casing. The anchoring mechanism 300 switches from the release state to the anchoring state, and the packer 10 completes the setting operation. During this process, the bellows-like structure of the outer casing 410 is compressed in the axial direction, and the gas inside the outer casing 410 is discharged through the one-way valve 150.

[0033] During the unsealing operation, a second pressure-holding ball is inserted from above the tubing column. The second pressure-holding ball sits on the second pressure-holding ball seat 220 to form a seal. Liquid is injected into the tubing column and pressurized. The second pressure-holding ball seat 220 is in a second pressure-holding state. The hydraulic pressure below the second pressure-holding ball seat 220 in the tubing cavity increases. The pressure of the liquid column acts on the inner wall of the working section 120. First, an annular jet hole 130 set near the installation section 110 is opened. The liquid column enters the corresponding first-stage hydraulic pressure-holding unlocking component in the multi-stage hydraulic pressure-holding unlocking component 420 through the annular jet hole 130. The first-stage hydraulic pressure-holding unlocking component completes the pressure-holding release action under hydraulic action. After release, the liquid column continues to flow along the tubing cavity of the working section 120 and opens the next annular jet hole 130, entering the second-stage hydraulic pressure-holding unlocking component, and so on. The multi-stage hydraulic pressure-holding unlocking component 420 completes the pressure-holding release step by step. After each stage of hydraulic pressure release component completes its pressure release, the axial constraint between the hydraulic pressure release component and the anchoring mechanism 300 is released. During the process of the multi-stage hydraulic pressure release component 420 releasing step by step, the anchoring mechanism 300 is driven to move towards the hydraulic cylinder sleeve 200. The slips of the anchoring mechanism 300 gradually retract radially and disengage from the inner wall of the sleeve, and the rubber sleeve gradually retracts radially and disengages from the inner wall of the sleeve. The anchoring mechanism 300 switches from the anchoring state to the release state, and the packer 10 completes the unsealing operation.

[0034] In one embodiment, the multi-stage hydraulic pressure-locking unlocking component 420 includes: The first ratchet sleeve 421 is slidably sleeved on the outer periphery of the working section 120 and connected to the anchoring mechanism 300. The inner wall of the first ratchet sleeve 421 has liquid channels 454 that are the same number as each ring jet hole 130 and are connected one-to-one. The end of the liquid channel 454 facing the mounting section 110 is a blind end. A first pressure-locking unlocking assembly 422 is sleeved on the outer periphery of the working section 120 and covers the outer periphery of the first ratchet sleeve 421 along the length direction of the central tube 100. A first piston pressure-locking chamber 423 is formed between the first pressure-locking unlocking assembly and the working section 120, communicating with one of the jet holes 130. The first piston pressure-locking chamber 423 is connected to the liquid flow channel 454. At least one second pressure-locking unlocking component 424 is provided. All second pressure-locking unlocking components 424 are sequentially sleeved on the outer periphery of the central tube 100 along the length direction of the working section 120. The second pressure-locking unlocking components 424 located close to the first pressure-locking unlocking component 422 cover the outer periphery of the first pressure-locking unlocking component 422. Each second pressure-locking unlocking component 424 and the working section 120 respectively form a second piston pressure-locking chamber that communicates with a jet hole 130.

[0035] Specifically, the first pressure-locking unlocking component 422 is a cylindrical structure, with its inner wall surface fitting or spaced against the outer wall surface of the first ratchet sleeve 421. The axial length of the first pressure-locking unlocking component 422 covers all or part of the outer circumferential surface of the first ratchet sleeve 421. A first piston pressure-locking chamber 423 is formed between the first pressure-locking unlocking component 422 and the working section 120, communicating with one of the jet holes 130. The first piston pressure-locking chamber 423 is an annular chamber or a partial chamber surrounding the outer circumference of the working section 120. This chamber communicates with the lumen through the corresponding jet hole 130, and at the same time, the first piston pressure-locking chamber 423 communicates with the liquid flow channel 454.

[0036] At least one second pressure-locking unlocking component 424 is sequentially sleeved on the outer periphery of the central tube 100 along the length of the working section 120. The second pressure-locking unlocking component 424, positioned close to the first pressure-locking unlocking component 422, covers the outer periphery of the first pressure-locking unlocking component 422; that is, the inner wall surface of the second pressure-locking unlocking component 424 is in contact with or spaced from the outer wall surface of the first pressure-locking unlocking component 422, forming a multi-layered sleeve structure nested from the inside out. Each second pressure-locking unlocking component 424 has a second piston pressure-locking chamber connected to a jet hole 130 between it and the working section 120. Each second piston pressure-locking chamber is connected to the tube cavity through a corresponding jet hole 130, and each second piston pressure-locking chamber is independent of the others. During the unsealing operation, when the second pressure-holding ball seat 220 is in the second pressure-holding state, the hydraulic pressure in the cavity increases, and the liquid enters the corresponding second piston pressure-holding chamber through each annular jet hole 130 in sequence. The hydraulic pressure in each second piston pressure-holding chamber acts on the corresponding second pressure-holding unlocking component 424 step by step. Each second pressure-holding unlocking component 424 unlocks step by step under the action of hydraulic pressure, releasing the axial constraint on the first ratchet sleeve 421 and the connecting seat. The elastic reset component releases elastic potential energy to drive the seated anchoring component to retract towards the working section 120, thereby achieving unsealing.

[0037] The operator can select the specific number of the second pressure-locking unlocking components 424 based on the actual downhole conditions, the anchoring force of the setting and anchoring components, and the maximum hydraulic pressure that the cavity can withstand. For example, there can be two, three, four, or more. All the second pressure-locking unlocking components 424 need to be sequentially fitted onto the outer periphery of the central tube 100 along the length of the working section 120, and each second pressure-locking unlocking component 424 and the working section 120 must form a second piston pressure-locking chamber connected to a jet orifice 130. The more second pressure-locking unlocking components 424 there are, the more unlocking stages there are, and the lower the hydraulic pressure required for each unlocking stage. This increases the safety and controllability of the unsealing operation. However, the axial dimensions and structural complexity of the packer 10 also increase accordingly. Therefore, a reasonable selection and balance needs to be made based on the actual working conditions.

[0038] It can be further clarified that, in the embodiment of the present invention, the number of second pressure-locking unlocking components is set to two. One of the two second pressure-locking unlocking components is a first second pressure-locking unlocking component, and the other is a second pressure-locking unlocking component. The first second pressure-locking unlocking component is connected to the first pressure-locking unlocking component, and the second second pressure-locking unlocking component is connected to the first second pressure-locking unlocking component. This achieves the function of sequentially nesting and connecting the first pressure-locking unlocking component and the two second pressure-locking unlocking components. Through this arrangement, the present invention can achieve the function of graded pressure-locking unlocking. It can also be further clarified that, in this embodiment, the number of rings in the example multi-ring jet orifice should be consistent with and correspond one-to-one with the number of rings in the set shear pins. Specifically, the ring jet orifice corresponding to the first shear pin is the first ring jet orifice, the ring jet orifice corresponding to the second shear pin is the second ring jet orifice, the ring jet orifice corresponding to the third shear pin is the third ring jet orifice, the ring jet orifice corresponding to the fourth shear pin is the fourth ring jet orifice, and the ring jet orifice corresponding to the fifth shear pin is the fifth ring jet orifice. Furthermore, the number of the first ring jet holes, the second ring jet holes, the third ring jet holes, the fourth ring jet holes, and the fifth ring jet holes can be the same or different. The number of jet holes in each ring can be set according to actual needs. Regardless of how the number of jet holes in each ring is set, the number of shear pins in each ring jet hole should be consistent with the number of corresponding shear pins and set one-to-one.

[0039] In some specific embodiments, the first ratchet sleeve 421 includes: The first sleeve 425 is slidably sleeved on the outer periphery of the working section 120 and connected to the anchoring mechanism 300. A liquid flow channel 454 is formed on the inner wall of the first sleeve 425. Multiple first shear pins 426, the number of which corresponds to the number of jet holes 130 (i.e., first annular jet holes), are inserted into and abut against the end of the first sleeve 425 away from the anchoring mechanism 300; and, The first ratchet ring 427 is interference-fitted to the outer periphery of the first sleeve 425. The first ratchet ring 427 is provided with multiple first ratchet rings 428 that are inclined towards the mounting section 110, and multiple first partition posts 429 that are spaced apart along its circumference and penetrate all the first ratchet rings 428. The first partition posts 429 divide all the first ratchet rings 428 into multiple first ratchet grooves 430 that are distributed along the circumference. All the first ratchet grooves 430 are engaged with the first pressure unlocking component 422. When the second pressure-holding ball seat 220 is in the second pressure-holding state, the liquid column in the central tube 100 can impact all the first shear pins 426 to make the jet hole 130 connect with the first piston pressure-holding chamber 423, and release the first sleeve 425, so that the first ratchet ring 428 is unlocked from the first pressure-holding unlocking assembly 422, driving the anchoring mechanism 300 to move towards the working section 120.

[0040] Specifically, the first sleeve 425 is a cylindrical structure, and its inner wall surface maintains a sliding fit with the outer wall surface of the working section 120 in the axial direction. The end of the first sleeve 425 near the mounting section 110 is fixedly connected to the connecting seat of the anchoring mechanism 300, so that the axial movement of the first sleeve 425 can be transmitted to the connecting seat, thereby driving the pressure transmission sleeve and the setting anchoring assembly of the anchoring mechanism 300 to move. A liquid flow channel 454 is formed on the inner wall of the first sleeve 425. The liquid flow channel 454 is opened along the inner wall surface of the first sleeve 425, and each liquid flow channel 454 is connected to one of the jet holes 130 in the corresponding first annular jet hole on the working section 120. When the first shear pin 426 is not cut off in the set-off state, the first shear pin 426 is inserted into the jet hole 130 and blocks the communication channel between the jet hole 130 and the liquid flow channel 454. The liquid in the tube cannot enter the liquid flow channel 454 and the first piston pressure chamber 423 through the jet hole 130. The first sleeve 425 remains stationary in the axial direction, and the anchoring mechanism 300 maintains the anchoring state.

[0041] Each first shear pin 426 is inserted into a corresponding jet hole 130 on the working section 120. One end of the first shear pin 426 extends into the jet hole 130 and blocks the outlet of the jet hole 130, while the other end of the first shear pin 426 abuts against the end face of the first sleeve 425 away from the anchoring mechanism 300. When the first shear pin 426 is not cut off, one end of it blocks the outlet of the jet hole 130, preventing the liquid in the pipe from entering the liquid flow channel 454 through the jet hole 130. At the same time, the first shear pin 426 abuts against the end face of the first sleeve 425, forming an axial positioning constraint on the first sleeve 425 and restricting the first sleeve 425 from moving axially toward the working section 120. The first shear pin 426 has a preset shear strength. When the impact force of the liquid column in the tube reaches the shear strength threshold of the first shear pin 426, the first shear pin 426 is sheared, and the outlets of all the jet holes 130 in the first annular jet hole are opened. The liquid in the tube enters the liquid flow channel 454 through the jet hole 130 and enters the first piston pressure chamber 423. At the same time, the axial positioning constraint of the first shear pin 426 on the first sleeve 425 is released, and the first sleeve 425 gains the freedom to move in the axial direction.

[0042] The first ratchet ring 427 is a ring-shaped structural component. Its inner wall surface is fastened to the outer wall surface of the first sleeve 425 through an interference fit. The first ratchet ring 427 moves synchronously with the first sleeve 425. The first ratchet ring 427 is provided with multiple first ratchet rings 428 that are all inclined towards the mounting section 110. The multiple first ratchet rings 428 are arranged at intervals along the axial direction of the first ratchet ring 427. Each first ratchet ring 428 is composed of multiple ratches arranged in the circumferential direction, and all ratches are inclined towards the mounting section 110. The ratchet is inclined toward the mounting section 110, giving the first ratchet ring 428 a one-way locking function: when the first ratchet ring 427 moves toward the mounting section 110 relative to the first pressure unlocking component 422, the inclined surface of the ratchet forms a forward sliding fit with the inner wall surface of the first pressure unlocking component 422, the ratchet is compressed and allows the first ratchet ring 427 to pass; when the first ratchet ring 427 moves toward the working section 120 relative to the first pressure unlocking component 422, the inclined surface of the ratchet forms a reverse engagement with the inner wall surface of the first pressure unlocking component 422, the ratchet engages with the inner wall surface of the first pressure unlocking component 422 and prevents the first ratchet ring 427 from moving in the opposite direction.

[0043] The first partition post 429 is a columnar structure extending along the axial direction of the first ratchet ring 427. Each first partition post 429 penetrates all first ratchet rings 428, dividing all first ratchet rings 428 into multiple circumferentially distributed first ratchet grooves 430. Each first ratchet groove 430 is formed by the ratchet segments between two adjacent first partition posts 429. The first partition post 429 divides the continuous annular ratchet structure into multiple independent arc-shaped ratchet segments. All first ratchet grooves 430 engage with the first pressure unlocking component 422. That is, the inner wall surface of the first pressure unlocking component 422 is provided with an engagement structure that matches the first ratchet grooves 430. The ratchet teeth in the first ratchet grooves 430 and the engagement structure of the first pressure unlocking component 422 engage with each other to form an axial lock. The first separator 429 makes each segment of the first ratchet groove 430 independent in the circumferential direction. When the first ratchet ring 427 moves toward the working section 120 under the action of axial force, the ratchet teeth in each segment of the first ratchet groove 430 can disengage from the first pressure unlocking component 422 segment by segment under the separation action of the first separator 429, reducing the axial force required for overall disengagement and making the unlocking process more stable and controllable.

[0044] In one embodiment, the first pressure release component 422 includes: The first unlocking ring 431 is sleeved on the outer periphery of the working section 120. The first unlocking ring 431 includes a first piston ring 432, a first connecting ring 433, and a plurality of first unlocking rods 434 that are integrally formed in sequence along the circumferential direction. The first piston ring 432 cooperates with the piston of the working section 120. All the first unlocking rods 434 have first meshing teeth on the side facing the working section 120 that mesh with the first ratchet ring 428. The outer periphery of the first connecting ring 433 is provided with a first abutment ring 435. Multiple second shear pins 436 are distributed circumferentially around the outer periphery of the working section 120. The number of second shear pins 436 is the same as that of another annular jet hole 130 (i.e., the second annular jet hole), and they are inserted one-to-one and abut against the first piston ring 432. The second shear pins 436 are located in the first piston pressure chamber 423. The second ratchet sleeve 437 is slidably sleeved on the outer periphery of the working section 120, and at least partially sleeved on the outer periphery of the first unlocking ring 431 and abutting against the first abutting ring 435. A second piston pressure chamber is formed between the second ratchet sleeve 437 and the first piston ring 432. The outer periphery of the second ratchet sleeve 437 engages with the adjacent second pressure unlocking assembly 424. Multiple third shear pins 438 are distributed circumferentially around the outer periphery of the working section 120 and abut against the end of the second ratchet sleeve 437 away from the first pressure-locking unlocking assembly 422. The number of third shear pins 438 is the same as that of the next ring jet hole (i.e., the third ring jet hole) and they are inserted one by one. The third shear pins 438 are located in the second piston pressure-locking chamber. The first sleeve 425 can enter the first connecting ring 433 and impact and shear the second shear pin 436. When it comes into contact with the first piston ring 432, it continues to press down to push the second ratchet sleeve 437 to shear all the third shear pins 438, so that the second ratchet sleeve 437 is disengaged from the adjacent second press-down unlocking assembly 424 and drives the anchoring mechanism 300 to move in the direction of the working section 120.

[0045] Specifically, the first piston ring 432, the first connecting ring 433, and multiple first unlocking rods 434 are made from a single blank through a one-time molding process. There are no welding seams or splicing gaps between the three. The integrally formed structure ensures the overall structural strength and pressure resistance of the first unlocking ring 431 in the downhole high-pressure environment.

[0046] The first piston ring 432 engages with the piston of the working section 120, forming a piston-sealing fit between the inner wall surface of the first piston ring 432 and the outer wall surface of the working section 120. The first piston ring 432 can slide axially along the outer wall surface of the working section 120. The piston-sealing fit between the first piston ring 432 and the working section 120 ensures the sealing of the first piston pressure chamber 423, preventing liquid leakage from the fit gap between the first piston ring 432 and the working section 120. The first piston ring 432 is located at one end of the first piston pressure chamber 423, forming the piston end wall of the first piston pressure chamber 423. When the hydraulic pressure in the first piston pressure chamber 423 increases, the hydraulic pressure acts on the end face of the first piston ring 432, generating a thrust in the axial direction.

[0047] The first abutment ring 435 is an annular flange structure extending circumferentially along the outer wall surface of the first connecting ring 433. The outer diameter of the first abutment ring 435 is larger than that of the first connecting ring 433. The first abutment ring 435 forms a stepped surface in the axial direction for abutting and engaging with the second ratchet sleeve 437. The inner diameter of the first connecting ring 433 is larger than the outer diameter of the first sleeve 425, allowing the first sleeve 425 to enter the inner cavity of the first connecting ring 433 during axial movement.

[0048] The tooth profile of the first engaging tooth matches the tooth profile of the ratchet on the first ratchet ring 428. The first engaging tooth engages with the ratchet in the first ratchet groove 430, forming an axial lock. The structure of multiple first unlocking rods 434 spaced circumferentially ensures that the biting force between the first engaging tooth and the first ratchet groove 430 is evenly distributed circumferentially, guaranteeing the balance and stability of the axial lock. In the set state, the first engaging tooth and the first ratchet groove 430 remain engaged, and the first unlocking ring 431 and the first ratchet ring 427 form an axial lock, restricting the movement of the first ratchet ring 427 and the first sleeve 425 towards the working section 120, thereby maintaining the anchoring state of the anchoring mechanism 300.

[0049] Each second shear pin 436 is inserted into one of the corresponding jet holes 130 on the working section 120. One end of the second shear pin 436 extends into the jet hole 130 and blocks its outlet, while the other end abuts against the end face of the first piston ring 432 facing the mounting section 110. When the second shear pin 436 is not cut off, one end of it blocks the outlet of the corresponding jet hole 130, preventing the liquid in the tube from entering the first piston pressure chamber 423 through the jet hole 130. At the same time, the other end of the second shear pin 436 abuts against the end face of the first piston ring 432, forming an axial positioning constraint on the first piston ring 432 and restricting its movement in the axial direction toward the working section 120. The second shear pin 436 is located inside the first piston pressure chamber 423. When the second shear pin 436 is cut, the outlet of the corresponding jet hole 130 is opened, and the liquid in the tube directly enters the first piston pressure chamber 423 through the jet hole 130, increasing the hydraulic pressure inside the first piston pressure chamber 423. The second shear pin 436 has a preset shear strength, which is selected according to the hydraulic pressure required for the unsealing operation.

[0050] The number of third shear pins 438 is the same as that of the next ring jet holes (i.e., the third ring jet holes), and they are inserted one-to-one. The third shear pins 438 are located in the second piston pressure chamber. Each third shear pin 438 is inserted into the corresponding jet hole 130 in the next ring jet hole 130 on the working section 120. One end of the third shear pin 438 extends into the jet hole 130 and blocks the outlet of the jet hole 130. The other end of the third shear pin 438 abuts against the end face of the second ratchet sleeve 437 away from the first pressure unlocking assembly 422. When the third shear pin 438 is not cut, one end of it blocks the outlet of the corresponding jet hole 130, preventing the liquid in the pipe from entering the second piston pressure chamber through the jet hole 130. Simultaneously, the other end of the third shear pin 438 abuts against the end face of the second ratchet sleeve 437, forming an axial positioning constraint on the second ratchet sleeve 437 and restricting its movement axially toward the working section 120. The third shear pin 438 is located within the second piston pressure chamber. When the third shear pin 438 is cut, the outlet of the corresponding jet hole 130 is opened, and the liquid in the pipe directly enters the second piston pressure chamber through the jet hole 130. The hydraulic pressure in the second piston pressure chamber increases, causing the second ratchet sleeve 437 to unlock from the adjacent second piston pressure unlocking assembly.

[0051] After the second-level unlocking is completed, all axial constraints of the multi-stage hydraulic pressure-locking unlocking component 420 on the first sleeve 425 and the connecting seat are released. The elastic reset component releases the accumulated elastic potential energy, and its restoring force drives the anchoring mechanism 300 to move in the direction of the working section 120 through the connecting seat. The pressure transmission sleeve extends, and the rubber sleeve and anchoring block of the seated anchoring component retract radially and detach from the inner wall of the sleeve. The packer 10 completes the first unlocking.

[0052] In some preferred embodiments, the second ratchet sleeve 437 includes: The second sleeve 439 is sleeved on the outer periphery of the working section 120 and abuts against the first abutting ring 435. All the third shear pins 438 are distributed at the end of the second sleeve 439 away from the first unlocking ring 431. The second sleeve 439 slides with the working section 120 and blocks the jet hole 130 corresponding to the third shear pins 438. The second ratchet ring 440 is interference-fitted to the outer periphery of the second sleeve 439. The second ratchet ring 440 is provided with multiple second ratchet rings 441 with the same inclination direction as the first ratchet ring 428, and multiple second partition posts 442 that are circumferentially spaced and pass through all the second ratchet rings 441. The second partition posts 442 divide all the second ratchet rings 441 into multiple second ratchet grooves 443 that are circumferentially spaced. All the second ratchet grooves 443 engage with their adjacent second pressure unlocking components 424. When the second sleeve 439 cuts the third shear pin 438, the liquid column entering the first piston pressure chamber 423 moves away from the installation section 110 through the first connecting ring 433, and disengages the second ratchet ring 440 and the adjacent second pressure unlocking assembly 424, thereby driving the anchoring mechanism 300 to move towards the working section 120.

[0053] Specifically, the second sleeve 439 is a cylindrical structure with a sliding fit between its inner wall and the outer wall of the working section 120, meaning that the second sleeve 439 can reciprocate along the outer wall of the working section 120 in the axial direction. The end of the second sleeve 439 near the first unlocking ring 431 abuts against the first abutting ring 435 on the outer periphery of the first connecting ring 433. The stepped surface of the first abutting ring 435 abuts against the end face of the second sleeve 439, allowing the axial movement of the first unlocking ring 431 to be transmitted to the second sleeve 439 via the first abutting ring 435, driving the second sleeve 439 to move synchronously. All the third shear pins 438 are distributed at the end of the second sleeve 439 away from the first unlocking ring 431. That is, the third shear pins 438 abut against the end face of the second sleeve 439 away from the first abutment ring 435. When the third shear pins 438 are not cut, they form an axial positioning constraint on the second sleeve 439, restricting the second sleeve 439 from moving axially away from the installation section 110. The second sleeve 439 slides with the working section 120 and blocks the jet hole 130 corresponding to the third shear pins 438. That is, the inner wall surface of the second sleeve 439 covers the outer outlet of the jet hole 130 corresponding to the third shear pins 438. When the third shear pins 438 are not cut, the sliding fit surface between the inner wall surface of the second sleeve 439 and the outer wall surface of the working section 120 blocks the outer outlet of the jet hole 130, and the liquid in the tube cannot enter the second piston pressure chamber through the jet hole 130. When the third shear pin 438 is cut off, the second sleeve 439 moves away from the installation section 110 under the action of axial thrust. The inner wall of the second sleeve 439 is released from the blockage of the outer outlet of the jet hole 130, the outer outlet of the jet hole 130 is opened, and the liquid in the tube enters the second piston pressure chamber through the jet hole 130.

[0054] The second ratchet ring 440 is a ring-shaped structural component. Its inner wall surface is fastened to the outer wall surface of the second sleeve 439 through an interference fit. The second ratchet ring 440 moves synchronously with the second sleeve 439. The second ratchet ring 440 is provided with multiple second ratchet rings 441 with the same inclination direction as the first ratchet ring 428. The multiple second ratchet rings 441 are arranged at intervals along the axial direction of the second ratchet ring 440. Each second ratchet ring 441 is composed of multiple ratches arranged in the circumferential direction. All ratches are inclined towards the mounting section 110, which is consistent with the inclination direction of the ratches on the first ratchet ring 428. The ratchet teeth on the second ratchet ring 441 are inclined toward the mounting section 110, giving the second ratchet ring 441 a one-way locking function: when the second ratchet ring 440 moves toward the mounting section 110 relative to the adjacent second pressure unlocking component 424, the inclined surface of the ratchet teeth forms a forward sliding engagement with the inner wall surface of the second pressure unlocking component 424, the ratchet teeth are compressed, and the second ratchet ring 440 is allowed to pass; when the second ratchet ring 440 moves away from the mounting section 110 relative to the adjacent second pressure unlocking component 424, the inclined surface of the ratchet teeth forms a reverse engagement with the inner wall surface of the second pressure unlocking component 424, the ratchet teeth are engaged with the inner wall surface of the second pressure unlocking component 424, and the second ratchet ring 440 is prevented from moving in the opposite direction. The second ratchet ring 441 is inclined in the same direction as the first ratchet ring 428, ensuring that the first ratchet sleeve 421 and the second ratchet sleeve 437 have the same locking direction in the setting state, both preventing their corresponding sleeves from moving towards the working section 120, thereby forming a multi-level axial constraint on the anchoring mechanism 300 in the setting state.

[0055] The second partition post 442 is a columnar structure extending along the axial direction of the second ratchet ring 440. Each second partition post 442 penetrates all second ratchet rings 441, dividing all second ratchet rings 441 into multiple circumferentially spaced second ratchet grooves 443. Each second ratchet groove 443 is formed by the ratchet segments between two adjacent second partition posts 442, and the second partition post 442 divides the continuous annular ratchet structure into multiple independent arc-shaped ratchet segments. All second ratchet grooves 443 engage with their adjacent second pressure unlocking components 424, that is, the inner wall surface of the adjacent second pressure unlocking components 424 is provided with an engagement structure that matches the second ratchet groove 443. The ratchet teeth in the second ratchet groove 443 and the engagement structure of the second pressure unlocking component 424 engage with each other to form an axial lock. The presence of the second partition post 442 makes each segment of the second ratchet groove 443 independent in the circumferential direction. When the second ratchet ring 440 moves away from the installation segment 110 under the action of axial force, the ratchet teeth in each segment of the second ratchet groove 443 can disengage from the second buckling unlocking component 424 segment by segment under the separation action of the second partition post 442, reducing the axial force required for overall disengagement and making the second-stage unlocking process more stable and controllable.

[0056] After unlocking, all axial constraints of the multi-stage hydraulic pressure-locking unlocking component 420 on the first sleeve 425 and the connecting seat are released. The elastic reset component releases the stored elastic potential energy, and its restoring force drives the anchoring mechanism 300 to move towards the working section 120 through the connecting seat. The pressure transmission sleeve extends, and the rubber sleeve and anchoring block of the seated anchoring component retract radially and detach from the inner wall of the sleeve. The packer 10 completes the second stage of unlocking.

[0057] In one embodiment, the second pressure release component 424 includes: The second unlocking ring 444 is sleeved on the outer periphery of the working section 120. The second unlocking ring 444 includes a second piston ring 445, a second connecting ring 446 and multiple second unlocking rods 447 integrally formed along the direction from the working section 120 to the mounting section 110. The second piston ring 445 cooperates with the piston of the working section 120. All the second unlocking rods 447 have second engagement teeth on the side facing the working section 120 that mesh with the second ratchet ring 441. The outer periphery of the second connecting ring 446 is provided with a second abutment ring 448. Multiple fourth shear pins 449 are distributed circumferentially around the outer periphery of the working section 120, and are all located inside the second connecting ring 446 and abut against the second piston ring 445. The number of fourth shear pins 449 is consistent with that of the next ring jet hole (i.e., the fourth ring jet hole), and they are inserted one by one and abut against the second piston ring 445. The third ratchet sleeve 450 is slidably sleeved on the outer periphery of the working section 120, and at least a portion of the third ratchet sleeve 450 is sleeved on the outer periphery of the second unlocking ring 444 and abuts against the second abutting ring 448. A second piston pressure chamber is formed between the third ratchet sleeve 450 and the second piston ring 445. The outer periphery of the third ratchet sleeve 450 engages with another second pressure unlocking assembly 424 adjacent to it. Multiple fifth shear pins 451 are distributed circumferentially around the outer periphery of the working section 120 and abut against the end of the third ratchet sleeve 450 away from the second pressure unlocking component 424. The number of fifth shear pins 451 is the same as that of another ring jet hole (i.e., the fifth ring jet hole) and they are inserted one by one. The second sleeve 439 can enter the second connecting ring 446 and impact and shear the fourth shear pin 449. When it comes into contact with the second piston ring 445, it continues to press down to push the third ratchet sleeve 450 to shear all the fifth shear pins 451, so that the third ratchet sleeve 450 is disengaged from the adjacent second press-down unlocking assembly 424 and drives the anchoring mechanism 300 to move towards the working section 120.

[0058] Specifically, the second piston ring 445, the second connecting ring 446, and the multiple second unlocking rods 447 are manufactured from a single blank through a one-time molding process. There are no welding seams or splicing gaps between the three. The integrally molded structure ensures the overall structural strength and pressure resistance of the second unlocking ring 444 in the downhole high-pressure environment, so that the hydraulic thrust borne by the second piston ring 445 can be transmitted to the second connecting ring 446 and the second unlocking rods 447 without loss.

[0059] The second piston ring 445 engages with the piston of the working section 120, forming a piston-sealing fit between the inner wall surface of the second piston ring 445 and the outer wall surface of the working section 120. The second piston ring 445 can slide axially along the outer wall surface of the working section 120. This piston-sealing fit ensures the sealing of the chamber containing the second piston ring 445, preventing liquid leakage from the fit gap between the second piston ring 445 and the working section 120. The second piston ring 445 is located at one end of the second piston pressure chamber, forming the piston end wall of the pressure chamber. When the hydraulic pressure in the pressure chamber increases, the hydraulic pressure acts on the end face of the second piston ring 445, generating a thrust in the axial direction.

[0060] The second abutment ring 448 is an annular flange structure extending circumferentially along the outer wall surface of the second connecting ring 446. The outer diameter of the second abutment ring 448 is larger than that of the second connecting ring 446. The second abutment ring 448 forms a stepped surface in the axial direction for abutting and engaging with the third ratchet sleeve 450. The inner diameter of the second connecting ring 446 is larger than the outer diameter of the second sleeve 439, allowing the second sleeve 439 to enter the inner cavity of the second connecting ring 446 during axial movement.

[0061] The tooth profile of the second engagement tooth matches the tooth profile of the ratchet on the second ratchet ring 441. The second engagement tooth engages with the ratchet in the second ratchet groove 443 to form an axial lock. The structure of multiple second unlocking rods 447 distributed circumferentially ensures that the biting force between the second engagement tooth and the second ratchet groove 443 is evenly distributed circumferentially, guaranteeing the balance and stability of the axial lock. In the set state, the second engagement tooth and the second ratchet groove 443 remain engaged, and an axial lock is formed between the second unlocking ring 444 and the second ratchet ring 440, restricting the movement of the second ratchet ring 440 and the second sleeve 439 away from the installation section 110, thereby maintaining the engagement state between the second ratchet sleeve 437 and the first buckling unlocking assembly 422. It can be understood that the second unlocking rod 447 and the first unlocking rod 434 correspond in structure and function, and both engage with the corresponding ratchet ring through their respective engagement teeth to form an axial lock between each unlocking assembly and the corresponding ratchet sleeve.

[0062] Each fourth shear pin 449 is inserted into a corresponding jet hole 130 in the fourth ring jet hole on the working section 120. One end of the fourth shear pin 449 extends into the jet hole 130 and blocks the outlet of the jet hole 130, while the other end of the fourth shear pin 449 abuts against the end face of the second piston ring 445 facing the working section 120. When the fourth shear pin 449 is not cut off, one end of it blocks the outlet of the corresponding jet hole 130, preventing the liquid in the tube from entering the second piston pressure chamber through the jet hole 130; at the same time, the other end of the fourth shear pin 449 abuts against the end face of the second piston ring 445, forming an axial positioning constraint on the second piston ring 445, restricting the second piston ring 445 from moving axially away from the mounting section 110. The fourth shear pin 449 is located inside the second connecting ring 446. When the second sleeve 439 enters the inner cavity of the second connecting ring 446, the second sleeve 439 can impact and shear the fourth shear pin 449. The fourth shear pin 449 has a preset shear strength, which is selected according to the hydraulic pressure required for the unsealing operation.

[0063] The third ratchet sleeve 450 is a cylindrical structure, and its inner wall surface and the outer wall surface of the working section 120 maintain a sliding fit relative to each other in the axial direction. The third ratchet sleeve 450 is at least partially sleeved on the outer periphery of the second unlocking ring 444, that is, the inner cavity of the third ratchet sleeve 450 accommodates at least part of the structure of the second unlocking ring 444, and the inner wall surface of the third ratchet sleeve 450 and the outer wall surface of the second unlocking ring 444 form a spaced fit or a sliding fit. The end of the third ratchet sleeve 450 near the second unlocking ring 444 abuts against the second abutting ring 448. That is, the end face of the third ratchet sleeve 450 abuts against the stepped surface of the second abutting ring 448 on the outer periphery of the second connecting ring 446. The second abutting ring 448 limits the third ratchet sleeve 450 in the axial direction. When the second unlocking ring 444 moves away from the installation section 110 under the action of hydraulic thrust, the second abutting ring 448 pushes the third ratchet sleeve 450 to move away from the installation section 110 in the same direction. A second piston pressure chamber is formed between the third ratchet sleeve 450 and the second piston ring 445. The second piston pressure chamber is an annular chamber or a partial chamber formed by the inner wall surface of the third ratchet sleeve 450, the outer wall surface of the second piston ring 445, and the outer wall surface of the working section 120. The outer periphery of the third ratchet sleeve 450 engages with the adjacent second buckling unlocking component 424. That is, the outer wall surface of the third ratchet sleeve 450 is provided with a ratchet structure or an engagement structure, which engages with the corresponding structure on the inner wall surface of the adjacent second buckling unlocking component 424 to form an axial lock.

[0064] The number of fifth shear pins 451 is the same as the number of jet holes 130 in the next ring of jet holes (i.e., the fifth ring of jet holes), and they are inserted one-to-one. Each fifth shear pin 451 is inserted into the corresponding jet hole 130 in the fifth ring of jet holes on the working section 120. One end of the fifth shear pin 451 extends into the jet hole 130 and blocks the outlet of the jet hole 130, while the other end of the fifth shear pin 451 abuts against the end face of the third ratchet sleeve 450 away from the second pressure-locking unlocking assembly 424. When the fifth shear pin 451 is not sheared, one end of it blocks the outlet of the corresponding jet hole 130, preventing the liquid in the tube from entering the next stage piston pressure-locking chamber through the jet hole 130; at the same time, the other end of the fifth shear pin 451 abuts against the end face of the third ratchet sleeve 450, forming an axial positioning constraint on the third ratchet sleeve 450, restricting the third ratchet sleeve 450 from moving axially away from the installation section 110. Understandably, the fifth scissor pin 451 and the third scissor pin 438 correspond in structure and function, both abutting against the end of their respective ratchet sleeves away from the previous unlocking component, and both being inserted into their respective jet holes 130 one by one.

[0065] After the first stage of unlocking is completed, if there is a subsequent second pressure-locking unlocking component 424 in the multi-stage hydraulic pressure-locking unlocking component 420, the third ratchet sleeve 450 continues to move and enters the corresponding connecting ring in the subsequent second pressure-locking unlocking component 424, repeating the above-mentioned step-by-step unlocking process until all levels of unlocking are completed. When the axial constraints of all levels in the multi-stage hydraulic pressure-locking unlocking component 420 are released, the elastic reset component releases the accumulated elastic potential energy, and its restoring force drives the anchoring mechanism 300 to move towards the working section 120 through the connecting seat. The pressure transmission sleeve extends, and the rubber sleeve and anchoring block of the setting anchoring component retract radially and detach from the inner wall of the sleeve. The packer 10 completes the third stage of unlocking.

[0066] To further clarify, the third ratchet sleeve 450 includes: The third sleeve 452 is sleeved on the outer periphery of the working section 120 and abuts against the second abutting ring 448. All the fifth shear pins 451 are distributed at the end of the third sleeve 452 away from the second unlocking ring 444. The third sleeve 452 slides with the working section 120 and seals the jet hole 130 corresponding to the fifth shear pin 451. The third ratchet ring 453 is interference-fitted to the outer periphery of the third sleeve 452. The third ratchet ring 453 is provided with multiple third ratchet rings with the same inclination direction as the first ratchet ring 428, and multiple third partition posts that are circumferentially spaced and penetrate all the third ratchet rings. The third partition posts divide all the third ratchet rings into multiple segments of third ratchet grooves that are circumferentially distributed. All the third ratchet grooves engage with the adjacent next second pressure unlocking component 424. When the fifth shear pin 451 is cut, the third sleeve 452 can move away from the installation section 110 by the liquid column entering the first piston pressure chamber 423 through the second connecting ring 446, and disengage the third ratchet ring 453 and the adjacent second pressure unlocking assembly 424, so that the anchoring mechanism 300 can be driven to move towards the working section 120 by all the unlocked second pressure unlocking assemblies 424, the first pressure unlocking assembly 422 and the first ratchet sleeve 421.

[0067] During the unsealing phase, the first sleeve 425 moves towards the working section 120 under hydraulic thrust, enters the inner cavity of the first connecting ring 433, and impacts and shears all the second shear pins 436. The first sleeve 425 continues to move until it abuts against the end face of the first piston ring 432. The hydraulic pressure in the first piston pressure chamber 423 increases, and the hydraulic pressure pushes the second sleeve 439 away from the installation section 110 through the first connecting ring 433 and the first abutting ring 435. After the second sleeve 439 shears the third shear pin 438, the inner wall of the second sleeve 439 is released from the blockage of the outer outlet of the jet hole 130 corresponding to the third shear pin 438, and the outer outlet of the jet hole 130 is opened. The second sleeve 439 continues to move, enters the inner cavity of the second connecting ring 446, and impacts and shears all the fourth shear pins 449. The second sleeve 439 continues to move until it abuts against the end face of the second piston ring 445. The hydraulic pressure in the second piston's pressure chamber increases, and the hydraulic pressure pushes the third sleeve 452 away from the installation section 110 through the second connecting ring 446 and the second abutment ring 448. The third sleeve 452 impacts and shears off all the fifth shear pins 451. After the fifth shear pins 451 are sheared off, the axial positioning constraint of the fifth shear pins 451 on the third sleeve 452 is released.

[0068] During the process of the third sleeve 452 cutting the fifth shear pin 451, the blind end of the first sleeve 425 has moved to the position of blocking the jet hole 130 corresponding to the first shear pin 426. The blind end of the first sleeve 425 blocks the outlet of the jet hole 130 corresponding to the first shear pin 426, and the liquid in the cavity cannot flow out through the jet hole 130. The second sleeve 439 has slid to the position that opens the jet hole 130 corresponding to the third shear pin 438. The inner wall of the second sleeve 439 no longer covers the outer outlet of the jet hole 130 corresponding to the third shear pin 438. The outer outlet of the jet hole 130 is in an open state, and the liquid in the cavity can enter the first piston pressure chamber 423 through the jet hole 130. After the third sleeve 452 cuts the fifth shear nail 451, the inner wall of the third sleeve 452 still covers the outer outlet of the jet hole 130 corresponding to the fifth shear nail 451, thus blocking the outer outlet of the jet hole 130.

[0069] Thus, during the process of the third sleeve 452 cutting off the fifth shear pin 451 and continuing to move, at least two rings of jet orifices 130 are open and connected to the first piston pressure chamber 423: one ring is the jet orifice 130 opened after the second shear pin 436 is cut off, and the other ring is the jet orifice 130 corresponding to the third shear pin 438, opened due to the sliding disengagement of the second sleeve 439 from its seal. These at least two rings of jet orifices 130 simultaneously and continuously supply liquid to the first piston pressure chamber 423, ensuring that the hydraulic pressure within the first piston pressure chamber 423 is adequately replenished and maintained. The liquid column in the first piston pressure chamber 423 continuously pushes the third sleeve 452 away from the installation section 110 through the second connecting ring 446. The third ratchet ring 453 moves synchronously with the third sleeve 452. The engagement between the ratchet on the third ratchet ring and the adjacent next second pressure unlocking component 424 is gradually released. Under the separation action of the third partition column, the ratchet in each segment of the third ratchet groove gradually disengages from the engagement structure of the next second pressure unlocking component 424. The third ratchet ring 453 and the adjacent other second pressure unlocking component 424 are then disengaged and unlocked.

[0070] At least two ring jet orifices 130 simultaneously supply fluid to the first piston pressure chamber 423, ensuring that the hydraulic pressure within the first piston pressure chamber 423 remains stable during the continuous movement of the third sleeve 452. This avoids hydraulic pressure drop and thrust attenuation caused by insufficient fluid flow from a single ring jet orifice 130. As each sleeve moves sequentially, the cumulative axial stroke of each sleeve increases progressively. The third sleeve 452 has the longest stroke among all sleeves, requiring sufficient axial thrust and a sufficiently long continuous thrust stroke to disengage from the next second pressure unlocking assembly 424. The coordinated fluid supply from at least two ring jet orifices 130 ensures that the hydraulic pressure within the first piston pressure chamber 423 remains at a sufficient level throughout the entire stroke of the third sleeve 452, providing continuous and stable axial thrust. This allows the third sleeve 452 to complete its entire stroke and completely disengage from the next second pressure unlocking assembly 424.

[0071] After the third ratchet ring 453 disengages from the adjacent second pressure unlocking assembly 424, all axial constraints on the connecting seat by the unlocked second pressure unlocking assemblies 424, the first pressure unlocking assembly 422, and the first ratchet sleeve 421 are released. The elastic reset member releases its accumulated elastic potential energy, and its restoring force drives the anchoring mechanism 300 to move towards the working section 120 through the connecting seat. Under the restoring force of the elastic reset member, the unlocked sleeves and unlocking rings at each stage retract as a whole in the axial direction towards the working section 120, providing sufficient release space for the anchoring mechanism 300. The pressure transmission sleeve extends, and the rubber sleeve and anchoring block of the setting anchoring assembly retract radially and detach from the inner wall of the sleeve until the unsealing operation of the packer 10 is completed.

[0072] Based on the same technical concept, in a second aspect, the present invention also proposes an integrated tubular column, comprising: Multiple packers 10 of the first aspect; and, Multiple tubing modules 20 are connected sequentially and alternately with all packers 10 to form an integrated tubing string. The integrated tubing string can be placed inside the casing of an oil well, and all packers 10 can switch between the setting state and the unsealing state of pressure release.

[0073] In this embodiment, the outer diameter of the integrated tubing string is smaller than the inner diameter of the casing. The integrated tubing string is run into the casing through wellhead equipment and extends along the axial direction of the casing to a predetermined well depth. After the integrated tubing string is run into the casing, each packer 10 corresponds to a target section position within the casing, and the tubing module 20 between two adjacent packers 10 corresponds to the well section between the two target sections.

[0074] It should be noted that the number of packers 10 and tubing modules 20 in the integrated tubing string can be flexibly adjusted according to the number and distribution of target formations in the oil well. The number of packers 10 corresponds to the number of target formations that need to be separated, and the number of tubing modules 20 is the number of packers 10 plus one. When the number of target formations increases, the number of packers 10 and tubing modules 20 can be increased accordingly, while the alternating arrangement structure of the integrated tubing string remains unchanged.

[0075] In one embodiment, the tubing module 20 includes a tubing section 21, a leak-proof well-washing joint 22, and a fracturing sleeve 23 arranged in sequence. The end of the tubing section 21 away from the leak-proof well-washing joint 22 is connected to one of the packers 10, and the fracturing sleeve 23 is connected to another packer 10. A fracturing space can be formed between any two adjacent packers 10.

[0076] In this embodiment, when all packers 10 are in the set state, the rubber sleeve and anchor block of the setting anchoring assembly of each packer 10 expand radially and abut against the inner wall of the casing, sealing the annular space between the inner wall of the casing and the outer wall of the central tube 100. After two adjacent packers 10 are set, the setting anchoring assemblies of the upper packer 10 and the lower packer 10 respectively seal the annular space at their respective positions, forming an independent sealing cavity between the two packers 10. This sealing cavity is the fracturing space. The upper end of the fracturing space is sealed by the setting anchoring assembly of the upper packer 10, and the lower end of the fracturing space is sealed by the setting anchoring assembly of the lower packer 10. The outer side of the fracturing space is the inner wall of the casing, and the inner side of the fracturing space is the outer wall surface of the tubing module 20. The fracturing orifice of the fracturing sleeve 23 is located on the tubing module 20 corresponding to the fracturing space. When the fracturing sleeve 23 is opened, the fracturing fluid in the inner cavity of the tubing module 20 enters the fracturing space through the fracturing orifice to perform fracturing operations on the target formation corresponding to the fracturing space.

[0077] Based on the same technical concept, in a third aspect, the present invention also proposes a method for layered operation of oil wells, using the integrated tubing string described in the second aspect, wherein the method for layered operation of oil wells includes the following steps: S100. Drilling operations are carried out in a preset oil production area to obtain a working well; wherein, a casing is installed in the working well.

[0078] Specifically, in this step, drilling operations are first carried out in the pre-designated oil production area. The pre-designated oil production area is an underground area containing multiple target oil and gas layers, determined based on geological exploration data. The purpose of the drilling operation is to form an operating well that penetrates multiple target oil and gas layers.

[0079] During drilling operations, drilling can be carried out in a predetermined oil production area based on pre-determined drilling data. It should be noted that, in this embodiment, the drilling data includes the well location coordinates, well depth, inclination angle, azimuth angle, and the depth range and interlayer spacing of each target oil and gas layer. After drilling is completed, casing is run into the wellbore and cementing is performed to form a stable wellbore structure. The casing is a steel tubular structure with an inner diameter larger than the outer diameter of the integrated tubing string. The casing is cemented to the wellbore wall using a cement sheath, and the inner wall of the casing forms a smooth cylindrical channel, providing space for the subsequent running and setting of the integrated tubing string.

[0080] It can be further explained that, in this embodiment, the casing depth should cover the depth range of all target oil and gas formations to ensure that each packer in the subsequent integrated tubing string can be set at the location corresponding to each target oil and gas formation. After the casing is run and cemented, a well cleaning operation can be performed inside the casing to confirm the unobstructedness and roundness of the casing inner wall and eliminate obstacles such as casing deformation and cement sheath residue that may affect the running of the integrated tubing string and packer setting.

[0081] S200. The integrated tubing string is lowered into the working well; wherein, an annulus is formed between the integrated tubing string and the casing, and the portion of the integrated tubing string protruding from the wellhead of the working well is connected to an external wellhead device.

[0082] After the integrated tubing string is lowered to the predetermined depth, its upper portion protrudes from the wellhead of the working well. This exposed portion connects to an external wellhead assembly. The external wellhead assembly is a surface device installed at the wellhead of the working well. It includes a wellhead sealing assembly and a hydraulic line interface. The wellhead sealing assembly forms a sealed fit with the outer wall of the integrated tubing string, preventing fluid leakage from the wellbore to the surface. The hydraulic line interface connects to a surface injection pump station or fracturing pump unit, used to inject fluid into the inner cavity of the integrated tubing string and establish hydraulic pressure. After the external wellhead assembly is connected to the integrated tubing string, the surface injection pump station or fracturing pump unit can inject fluid into the inner cavity of the integrated tubing string through the external wellhead assembly, providing hydraulic power for subsequent setting and stratified fracturing operations.

[0083] It is important to note that during the lowering of the integrated tubing string, the setting and anchoring components of each packer are in an unset state. This means that the rubber sleeves and anchor blocks of each packer are in a radially contracted state, the outer diameter of each packer is smaller than the inner diameter of the casing, and the integrated tubing string can move freely within the casing. All levels of the shear pins in the multi-stage hydraulic pressure-locking unlocking components of each packer are in good condition, the engagement between the ratchet sleeves at each stage and the unlocking components at each stage is locked, and the elastic reset components are in a natural or pre-compressed state.

[0084] S300. Pressurize the integrated tubing string through the external wellhead device and perform a setting operation to divide the annulus into multiple fracturing spaces spaced apart along the extension direction of the working well.

[0085] After each packer is set, the setting and anchoring assembly of each packer seals the annulus between the inner wall of the casing and the outer wall of the central tube at the packer's location. The annulus region between two adjacent packers is sealed and anchored at their respective locations by the setting and anchoring assemblies of the upper and lower packers, forming independent sealed cavities, which are the fracturing spaces. After all packers are set, the annulus is divided into multiple fracturing spaces spaced apart along the extension direction of the working well. These fracturing spaces are not interconnected, and each fracturing space corresponds to a target oil and gas formation.

[0086] It should be further explained that after the setting operation is completed, the elastic reset components in the multi-stage hydraulic pressure-locking unlocking mechanisms of each packer are compressed and accumulate elastic potential energy during the setting process. The engagement between the various stages of shear pins, ratchet sleeves, and unlocking components maintains the setting state of the setting anchoring assembly, preventing the restoring force of the elastic reset components from causing the setting anchoring assembly to retract. The setting state of each packer remains stable under the axial locking action of the multi-stage hydraulic pressure-locking unlocking mechanisms, and setting can be maintained without continuous hydraulic pressure.

[0087] S400. For any of the fracturing spaces, a ball is thrown into the first pressure-retaining ball seat located below and adjacent to it, so as to perform stratification operation on the corresponding fracturing space through the tubing module.

[0088] It is important to note that during stratified fracturing operations, it is preferable to fracture each fracturing space sequentially from bottom to top. Specifically, the first fracturing ball is first inserted into the first pressure-retaining ball seat of the lowest packer to fracturing the lowest fracturing space. After fracturing of the lowest fracturing space is completed, the second fracturing ball is inserted into the first pressure-retaining ball seat of the second-to-last packer to fracturing the second-to-last fracturing space, and so on, until all fracturing spaces have been fracturing. This bottom-to-top fracturing sequence ensures that each fracturing ball can fall freely along the lumen to the target first pressure-retaining ball seat without being blocked by fracturing balls already inserted above.

[0089] In this embodiment, multiple packers and multiple tubing modules are alternately connected to form an integrated tubing string. A single run into the working well allows for the simultaneous setting and stratified isolation of multiple target oil and gas formations. Stratified fracturing of each target oil and gas formation is achieved through sequential ball dropping and layer-by-layer fracturing. Each fracturing space is independent, ensuring the independence and specificity of stratified fracturing and preventing cross-contamination and pressure interference between different target oil and gas formations. The entire operation requires only one tubing string run, one setting, and sequential ball dropping to complete multi-segment stratified fracturing, reducing the number of tubing string trips and the operation time, thus lowering operating costs. All packers can be unsealed through a multi-stage unlocking process triggered by hydraulic pressure within the tubing cavity, eliminating the need for mechanical tools or cables for individual unsealing. This further simplifies the unsealing process and improves the overall efficiency and economy of stratified well operations.

[0090] The above are merely exemplary embodiments of the present invention and do not limit the scope of the patent of the present invention. All equivalent structural transformations made using the contents of the present invention specification and drawings under the technical concept of the present invention, or direct / indirect applications in other related technical fields, are included within the scope of patent protection of the present invention.

Claims

1. A packer, characterized in that, include: The central tube includes an integrally formed mounting section and a working section. The working section has multiple rings of jet holes distributed at intervals along the length of the central tube and initially in a blocked state. One ring of jet holes is located close to the mounting section. The end of the mounting section away from the working section is interference-fitted with an abutment seat. A hydraulic cylinder liner is installed at the end of the working section away from the mounting section. A first pressure-blocking ball seat is installed in the cavity of the end of the mounting section away from the working section. A second pressure-blocking ball seat is installed at the junction of the mounting section and the working section. An anchoring mechanism, wherein the anchoring mechanism is sleeved on the outer periphery of the mounting section, with one end abutting against the abutment seat and the other end extending toward the working section; and, A hydraulic pressure-locking unlocking mechanism is installed in the working section. The hydraulic pressure-locking unlocking mechanism includes an outer shell and a multi-stage hydraulic pressure-locking unlocking component. The outer shell has a bellows-like structure and its two ends are respectively connected to the hydraulic cylinder liner and the anchoring mechanism. The multi-stage hydraulic pressure-locking unlocking component is sleeved on the outer periphery of the working section and one end is connected to the anchoring mechanism. The outer shell is sleeved on the outer periphery of the multi-stage hydraulic pressure-locking unlocking component. A one-way valve that can discharge gas inside the outer shell is provided on the outer shell. Specifically, when the first pressure-blocking ball seat is in the first pressure-blocking state, the hydraulic cylinder liner can push the hydraulic pressure-blocking unlocking mechanism to move towards the abutment seat, causing the anchoring mechanism to switch from the release state to the anchoring state; when the second pressure-blocking ball seat is in the second pressure-blocking state, the liquid column in the central tube opens the jet hole near the installation section and enters the multi-stage hydraulic pressure-blocking unlocking component, releasing pressure step by step, driving the anchoring mechanism to move towards the hydraulic cylinder liner and switch from the anchoring state to the release state.

2. The packer as claimed in claim 1, characterized in that, The multi-stage hydraulic pressure-locking unlocking component includes: A first ratchet sleeve is slidably fitted onto the outer periphery of the working section and connected to the anchoring mechanism. A liquid flow channel is formed on the inner wall of the first ratchet sleeve, which is consistent with the number of jet holes in each ring and is connected to each other. The end of the liquid flow channel facing the installation section is a blind end. A first pressure-locking unlocking assembly is sleeved on the outer periphery of the working section and covers the outer periphery of the first ratchet sleeve along the length direction of the central tube. A first piston pressure-locking chamber is formed between the first pressure-locking unlocking assembly and the working section, communicating with one of the jet holes. The first piston pressure-locking chamber is also communicating with the liquid flow channel. At least one second pressure-locking unlocking component, all second pressure-locking unlocking components are sequentially sleeved on the outer periphery of the central tube along the length direction of the working section, and the second pressure-locking unlocking components located close to the first pressure-locking unlocking component cover the outer periphery of the first pressure-locking unlocking component, and a second piston pressure-locking chamber communicating with one of the jet holes is formed between each second pressure-locking unlocking component and the working section.

3. The packer as described in claim 2, characterized in that, The first ratchet sleeve includes: A first sleeve is slidably fitted onto the outer periphery of the working section and connected to the anchoring mechanism, and the liquid flow channel is formed on the inner wall of the first sleeve. Multiple first shear pins, the number of which corresponds to the number of jet holes, are inserted into and abut against the end of the first sleeve furthest from the anchoring mechanism; and... The first ratchet ring is interference-fitted to the outer periphery of the first sleeve. The first ratchet ring is provided with multiple first ratchet rings that are inclined towards the mounting section, and multiple first partition posts that are spaced apart circumferentially and penetrate all the first ratchet rings. The first partition posts divide all the first ratchet rings into multiple first ratchet grooves distributed circumferentially, and all the first ratchet grooves engage with the first pressure unlocking component. When the second pressure-holding ball seat is in the second pressure-holding state, the liquid column in the central tube can impact all the first shear pins to make the jet hole connect with the first piston pressure-holding chamber, and release the first sleeve, so that the first ratchet ring is unlocked from the first pressure-holding unlocking assembly, and drive the anchoring mechanism to move in the direction of the working section.

4. The packer as described in claim 3, characterized in that, The first pressure release component includes: The first unlocking ring is sleeved on the outer periphery of the working section. The first unlocking ring includes a first piston ring, a first connecting ring and a plurality of first unlocking rods that are integrally formed in sequence and distributed circumferentially. The first piston ring cooperates with the piston of the working section. All the first unlocking rods have first biting teeth that mesh with the first ratchet ring on the side facing the working section. The outer periphery of the first connecting ring is provided with a first abutting ring. Multiple second shear pins are distributed circumferentially around the outer periphery of the working section. The number of second shear pins is the same as that of the jet holes of the other ring, and they are inserted into each other and abut against the first piston ring. The second shear pins are located in the first piston pressure chamber. The second ratchet sleeve is slidably sleeved on the outer periphery of the working section, and at least partially sleeved on the outer periphery of the first unlocking ring and abutting against the first abutting ring. The second ratchet sleeve and the first piston ring form the second piston pressure chamber. The outer periphery of the second ratchet sleeve engages with the adjacent second pressure unlocking component. Multiple third shear pins are distributed circumferentially around the outer periphery of the working section and abut against the end of the second ratchet sleeve away from the first pressure-locking unlocking component. The number of the third shear pins is the same as the number of the jet holes in the next ring and they are inserted one by one. The third shear pins are located in the second piston pressure-locking chamber. The first sleeve can enter the first connecting ring and impact and shear the second shear pin. When it abuts against the first piston ring, it continues to press down to push the second ratchet sleeve to shear all the third shear pins, so that the second ratchet sleeve disengages from the adjacent second press-down unlocking assembly and drives the anchoring mechanism to move in the direction of the working section.

5. The packer as claimed in claim 4, characterized in that, The second ratchet sleeve includes: The second sleeve is sleeved on the outer periphery of the working section and abuts against the first abutting ring. All the third shear pins are distributed at the end of the second sleeve away from the first unlocking ring. The second sleeve slides with the working section and blocks the jet hole corresponding to the third shear pin. The second ratchet ring is interference-fitted to the outer periphery of the second sleeve. The second ratchet ring is provided with multiple second ratchet rings that are inclined in the same direction as the first ratchet ring, and multiple second partition posts that are circumferentially spaced and penetrate all the second ratchet rings. The second partition posts divide all the second ratchet rings into multiple second ratchet grooves that are circumferentially spaced. All the second ratchet grooves engage with the adjacent second pressure unlocking component. When the second sleeve cuts the third shear pin, the liquid column entering the first piston pressure chamber moves away from the installation section through the first connecting ring, and disengages the second ratchet ring and the adjacent second pressure unlocking assembly, thereby driving the anchoring mechanism to move towards the working section.

6. The packer as claimed in claim 5, characterized in that, The second pressure release component includes: The second unlocking ring is sleeved on the outer periphery of the working section. The second unlocking ring includes a second piston ring, a second connecting ring and multiple second unlocking rods integrally formed in sequence along the direction from the working section to the mounting section. The second piston ring cooperates with the piston of the working section. All the second unlocking rods have second biting teeth on their sides facing the working section that mesh with the second ratchet ring. The outer periphery of the second connecting ring is provided with a second abutment ring. Multiple fourth shear pins are distributed circumferentially around the outer periphery of the working section, and are all located inside the second connecting ring and abut against the second piston ring. The number of the fourth shear pins is the same as that of the jet holes in the next ring, and they are inserted one by one and abut against the second piston ring. The third ratchet sleeve is slidably sleeved on the outer periphery of the working section, and at least a portion of the third ratchet sleeve is sleeved on the outer periphery of the second unlocking ring and abuts against the second abutting ring. The third ratchet sleeve and the second piston ring form the second piston pressure chamber. The outer periphery of the third ratchet sleeve engages with another second pressure unlocking component adjacent to it. Multiple fifth shear pins are distributed circumferentially around the outer periphery of the working section and abut against the end of the third ratchet sleeve away from the second pressure unlocking component. The number of fifth shear pins is the same as the number of jet holes in the next ring and they are inserted one by one. The second sleeve can enter the second connecting ring and impact and shear the fourth shear pin. When it abuts against the second piston ring, it continues to press down to push the third ratchet sleeve to shear all the fifth shear pins, so that the third ratchet sleeve disengages from the adjacent second press-down unlocking assembly and drives the anchoring mechanism to move towards the working section.

7. The packer as claimed in claim 6, characterized in that, The third ratchet sleeve includes: The third sleeve is sleeved on the outer periphery of the working section and abuts against the second abutting ring. All the fifth shear pins are distributed at the end of the third sleeve away from the second unlocking ring. The third sleeve slides with the working section and seals the jet hole corresponding to the fifth shear pin. The third ratchet ring is interference-fitted to the outer periphery of the third sleeve. The third ratchet ring is provided with multiple third ratchet rings with the same inclination direction as the first ratchet ring, and multiple third partition posts that are circumferentially spaced and penetrate all the third ratchet rings. The third partition posts divide all the third ratchet rings into multiple circumferentially distributed third ratchet grooves. All the third ratchet grooves engage with the adjacent next second pressure unlocking component. When the fifth shear pin is cut, the third sleeve can move the liquid column entering the first piston pressure chamber away from the installation section through the second connecting ring, and disengage the third ratchet ring and the adjacent second pressure unlocking component, so that the anchoring mechanism can be driven to move towards the working section by all the unlocked second pressure unlocking components, the first pressure unlocking component and the first ratchet sleeve.

8. An integrated tubular column, characterized in that, include: Multiple packers as described in any one of claims 1 to 7; as well as, Multiple tubing modules are sequentially and alternately connected with all packers to form the integrated tubing string. The integrated tubing string can be placed inside the casing of an oil well, and all packers can switch between a set state and a depressurized release state.

9. The integrated tubular column as described in claim 8, characterized in that, The tubing module includes a tubing section, a leak-proof well-washing joint, and a fracturing sleeve arranged in sequence. The end of the tubing section away from the leak-proof well-washing joint is connected to one of the packers, and the fracturing sleeve is connected to the other packer. A fracturing space can be formed between any two adjacent packers.

10. A method for stratified operation of oil wells, characterized in that, The oil well stratification operation method, using the integrated tubing string as described in claim 8 or 9, includes the following steps: Drilling operations are carried out in a predetermined oil production area to obtain a working well; wherein, a casing is installed in the working well; The integrated tubing string is lowered into the working well; wherein, an annulus is formed between the integrated tubing string and the casing, and the portion of the integrated tubing string protruding from the wellhead of the working well is connected to an external wellhead device. The external wellhead device is used to pressurize the integrated tubing string and perform a setting operation to divide the annulus into multiple fracturing spaces that are spaced apart along the extension direction of the working well. For any of the fracturing spaces, a ball is thrown into the first pressure-retaining ball seat located below and adjacent to it, so as to perform stratification operations on the corresponding fracturing space through the tubing module.

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