A perforation-resistant downhole packer

Abstract

This patent discloses an anti-impact downhole packer for perforation, specifically relating to the field of oil and gas well development. Its shock-absorbing mechanism includes a limiting sleeve, a disc spring, and a shock-absorbing rubber sleeve; the upper end of the shock-absorbing mechanism includes a centralizing mechanism, composed of a centralizer, a spring plate, and a centralizer friction plate; the centralizing mechanism contains an unsealing mechanism, composed of a lower spindle and a guide ring; the upper end of the centralizing mechanism includes a setting mechanism, the two mechanisms being connected by the guide ring, and the setting mechanism includes an opening ring clamp, a locking sleeve, and slips; the upper end of the setting mechanism includes a sealing mechanism, composed of two rubber sleeves, with a top shoe and a bottom shoe at the top and bottom of the sleeves; the upper end of the sealing mechanism includes an anchoring mechanism, with a hydraulic anchor slip and an elastic limiting structure at its upper end; this anti-impact downhole packer for perforation can automatically activate when facing a downhole perforation, preventing the high-intensity vibration and impact generated by the downhole perforation from affecting the packer's performance, improving the packer's setting efficiency, and reducing drilling costs.

Description

Technical Field

[0001] This patent relates to the field of drilling engineering for oil and gas development, and in particular to an anti-impact downhole packer for perforation. Background Technology

[0002] With the continuous advancement of oil and gas extraction technologies, downhole operations place increasingly higher demands on the performance of packers. While existing downhole packers play a crucial role in operations such as stratified oil and gas well production, acid fracturing, and well testing, several technical challenges remain. Firstly, traditional packers have limitations in terms of high pressure resistance, high temperature resistance, and corrosion resistance. During downhole perforation operations, the sealing performance of packers is subjected to downhole impacts.

[0003] The impact of these factors limits their use in complex well conditions. Especially during the development of deep oil and gas reservoirs, the high temperature, high pressure, and corrosive media at the wellbore pose greater challenges to the long-term stability and sealing performance of packers. Furthermore, existing packers are complex to operate during setting and retrieval, resulting in low efficiency and susceptibility to wellbore conditions such as wellbore irregularities and wellbore diameter variations, which can lead to unstable setting or difficulty in retrieval. Currently available packers often have complex structural designs, which not only increases manufacturing costs but also makes them prone to malfunctions during downhole operations, affecting operational safety.

[0004] Chinese patent application CN202411077949.1 discloses an external packer for cementing, comprising a packer body, a central tube, an upper connector, a pressure seat, a shoe seat, several slips, and two rubber sleeves. The central tube includes an upper tube and a lower tube, the upper tube being fixedly connected to the upper connector and the lower tube being fixedly connected to the shoe seat. A locking groove is formed on the upper part of the slips near the shoe seat. The packer also includes several limiting mechanisms, evenly arrayed at equal angles along the circumference of the pressure seat. Each limiting mechanism includes a limiting shaft, a limiting spring, and an anti-crossing mechanism. One end of the limiting shaft is slidably connected to the upper tube, and the other end is fixedly connected to the lower tube. The limiting spring is sleeved outside the limiting shaft, with both ends fixedly connected to the upper and lower tubes respectively. The anti-crossing mechanism is connected to the pressure seat. This device prevents further expansion of the slips when the rubber sleeves open after the slips are tightened inside the pipe wall, thus avoiding damage to the pipe wall.

[0005] Chinese patent application CN202411065118.2 discloses an adjustable packer for oil wells used in oil development, including a housing, a sealing pressure plate, a sealing rubber block, and an adjustment component. The adjustment component includes a first drive rod, a drive disc, a clutch disc, a control disc, and a second drive rod. The clutch disc is configured to consist of multiple sector discs, and these sector discs can move independently vertically. When the sealing rubber block deforms to fit against the inner wall of the tubing, if the drive disc continues to rotate and there is local wear on the force ring or clamping teeth, or if foreign matter gets stuck between the force ring and clamping teeth, the multiple independently vertically moving sector discs can move independently to address these issues, dispersing local pressure and extending the service life of the drive disc or sector discs. Furthermore, when a sector disc or clamping tooth is damaged, it can be replaced individually, reducing maintenance costs.

[0006] However, the above-mentioned patent applications still have the following defects in implementation:

[0007] The above methods are limited by the complex underground environment, and the complex structure and control system of the device itself cannot withstand severe impacts and vibrations underground, making it difficult to adapt to the special underground environment and resulting in high operating costs.

[0008] Therefore, in response to the problem that packers cannot operate effectively due to downhole perforation, this patent proposes an anti-impact downhole packer for perforation. The aim is to improve the packer's explosion-proof, impact-proof, vibration-resistant, and pressure-resistant performance under complex well conditions by improving the packer's structural design, material selection, and operating mechanism, simplifying the operation process, improving operational efficiency, and reducing manufacturing costs, so as to meet the high standards and strict requirements of modern oil and gas well development. Summary of the Invention

[0009] The main objective of this invention is to provide an anti-shock downhole packer for perforation, which can effectively prevent the impact of high-intensity shock waves and vibrations during downhole perforation on the packer's setting efficiency, and can adaptively respond to downhole perforation impacts; improve the packer's explosion-proof, shock-proof, vibration-resistant, and pressure-resistant performance under complex well conditions, simplify the operation process, improve operational efficiency, and reduce manufacturing costs, so as to meet the high standards and strict requirements of modern oil and gas well development.

[0010] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0011] This invention provides an anti-impact downhole packer for perforation, comprising a hydraulic anchor, fixing screws, springs, fixing plates, top shoe, rubber sleeves, bottom shoe, locking sleeves, slips, open ring clamps, guide rings, spring plates, centralizer friction plates, fixing blocks, centralizers, limiting sleeves, disc springs, lower mandrels, shock-absorbing rubber sleeves, hydraulic anchor slips, a central tube, and limiting plates. The shock-absorbing rubber sleeves are evenly fitted around the lower mandrel, and are secured by limiting plates on the lower mandrel.

[0012] The step is used for axial positioning; the lower spindle is provided with a disc spring boss in the middle, the lower part of the disc spring is fixedly connected to the disc spring boss, and the upper part is fixedly connected to the support surface at the lower end of the variable track ring.

[0013] The limiting sleeve is fitted outside the disc spring, and its upper part is fixedly connected to the straightener by a snap fastener;

[0014] The T-shaped groove on the upper part of the open ring mates with the T-shaped boss of the slip and provides axial positioning for the slip.

[0015] The locking sleeve is fitted outside the lower spindle, and the upper end of the locking pad is engaged with the inclined surface of the locking sleeve.

[0016] The upper end of the locking sleeve and the bottom shoe are in surface contact, and the bottom shoe is fitted outside the lower spindle; the top shoe is fitted outside the lower spindle, and two rubber tubes are installed between the bottom shoe and the top shoe;

[0017] The top shoe is equipped with a hydraulic anchor, and the hydraulic anchor has a central tube inside, and the hydraulic anchor is connected to the lower top shoe through the central tube.

[0018] Optionally or preferably, the bottom of the lower mandrel is provided with a threaded stepped surface, and the lower mandrel and the lower drill rod are connected by a thread.

[0019] Optionally or preferably, the variable track ring has two axial guide grooves, and the lower spindle is provided with two guide sliders.

[0020] Optionally or preferably, the rubber tubes are separated by a limiting piece.

[0021] Optionally or preferably, the slip is provided with a friction block, and the hydraulic anchor slip is provided with a hydraulic anchor friction block. Optionally or preferably, the lower mandrel and the central tube are clearance-fitted.

[0022] Optionally or preferably, the locking sleeve is provided with a V-shaped groove.

[0023] The perforation anti-impact downhole packer provided by this invention operates downhole with its hydraulic anchor connected to the upper drill pipe and its lower mandrel connected to the lower drill pipe or lower drill collar. When the packer reaches the predetermined setting position with the drill string system, the friction blocks on the centralizer friction plates will make tight contact with the casing wall due to the pushing action of the spring plates. The drill string is then raised 20-30cm and lowered 50-70cm, and the guide slider will slide within the axial guide groove to complete the track-changing operation. Then, the packer slips will slide into position. Driven by the sleeve, it expands radially, and the friction block makes close contact with the well wall to fix the anchoring mechanism; further, the top shoe and bottom shoe compress the rubber sleeve to achieve the effect of sealing the annulus; when the downhole pressure is too high, the lower pressure will be transmitted to the inside of the hydraulic anchor, and the compression spring will push the hydraulic anchor slip to move radially, further anchoring the packer. The hydraulic anchor fixes the position of the packer through hydraulic action, preventing the packer from moving up and down in the wellbore due to changes in hydraulic column pressure, working pressure or formation pressure, thus extending the service life of the packer.

[0024] Meanwhile, the outer end of the shock-absorbing rubber sleeve on the lower mandrel forms a bowl-shaped space with the casing wall due to friction. When perforating downhole, this bowl-shaped space acts as a sealing cup against the casing wall, blocking the impact of the downhole perforation. Furthermore, the disc spring mounted on the mandrel buffers axial impact and vibration, further preventing the rubber sleeve of the setting mechanism from being affected by downhole impacts and ensuring its sealing performance. After the setting operation is completed, the drill string is continuously pulled up to activate the sealing element.

[0025] The packer contracts, releasing itself from contact with the wellbore; subsequently, it can be removed from the wellbore along with the tubing, completing the setting and unsealing operations.

[0026] In summary, the perforation-resistant downhole packer of the present invention buffers downhole perforation impacts and vibrations, absorbs the shock wave energy generated during perforation, and reduces damage to the packer and its sealing elements. The impact-resistant packer can maintain sealing performance while resisting the instantaneous high pressure generated during perforation. It can isolate the perforation zone from other zones, preventing high-pressure fluids or debris generated during perforation from entering other zones, ensuring the packer's sealing efficiency, and guaranteeing the accuracy and safety of the operation.

[0027] By adopting the above technical solution, compared with the prior art, the embodiments of the present invention have at least the following beneficial effects:

[0028] 1. This invention has high reliability. By setting up a shock-absorbing rubber sleeve to form a bowl-shaped space with the casing wall, it isolates the perforation section and absorbs impact energy, thereby reducing the risk in perforation operations and improving the safety of downhole operations.

[0029] 2. This invention, by installing a disc spring on the lower mandrel, can effectively resist perforation impact, buffer axial vibration, and reduce packer damage and operation interruption caused by perforation impact. The anti-impact downhole packer helps improve overall operation efficiency. 3. This invention, by setting slips and hydraulic anchors, can effectively isolate different production or injection layers, preventing fluid cross-contamination between layers, thereby improving the extraction efficiency of oil, gas, water, and other fluids or the efficiency of water injection; the use of a variable track ring simplifies the setting operation mechanism, making the setting and recovery process faster, reducing operation time and labor intensity. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0031] Figure 2 This is a schematic diagram of the overall external structure of the present invention when it is not sealed.

[0032] Figure 3 This is a schematic diagram of the overall cross-sectional structure of the present invention before it is set in place;

[0033] Figure 4 This is a schematic diagram of the overall cross-sectional structure of the present invention during setting;

[0034] Figure 5 This is a schematic diagram of the track-changing ring structure of the present invention;

[0035] Figure 6 This is a schematic diagram of the lower mandrel structure of the present invention;

[0036] In the diagram: 1. Hydraulic anchor; 101. Hydraulic anchor slip; 102. Fixing clamp; 103. Fixing screw; 104. Spring; 105. Hydraulic anchor friction block; 2. Top shoe; 3. Rubber sleeve; 4. Bottom shoe; 5. Locking sleeve; 501. Sleeve bevel; 502. V-shaped groove; 6. Slip; 601. Friction block; 602. T-shaped boss; 7. Open ring clamp; 701. T-shaped groove; 8. Centralizer; 801. Track changing ring; 802. Spring plate; 803. Centralizer friction plate; 804. Fixing block; 805.

[0037] 9. Axial guide groove; 10. Limiting sleeve; 11. Disc spring; 12. Lower spindle; 13. Limiting step; 14. Disc spring boss; 15. Threaded step surface; 16. Guide slider; 17. Shock-absorbing rubber sleeve; 18. Central tube; 19. Limiting plate. Detailed Implementation

[0038] To make the technical means, creative features, achieved objectives, and effects of this patent easily understood, the invention is further described below in conjunction with specific embodiments. Obviously, the described embodiments are merely some embodiments of the invention, not all embodiments. Based on the embodiments of the invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0039] like Figures 1 to 6 As shown:

[0040] This invention proposes an explosion-proof, heat-insulating, and fire-extinguishing downhole tool for gas drilling, comprising a hydraulic anchor 1, a fixing screw 103, a spring 104, a fixing clamp 102, a top shoe 2, a rubber sleeve 3, a bottom shoe 4, a locking sleeve 5, a slip 6, an open ring 7, a guide ring 801, a spring plate 802, a centralizer friction plate 803, a fixing block 804, a centralizer 8, a limiting sleeve 9, a disc spring 10, a lower spindle 11, a shock-absorbing rubber sleeve 12, a hydraulic anchor slip 101, a central tube 13, and a limiting plate 14. The shock-absorbing rubber sleeve 12 is evenly fitted around the lower spindle 11 and is axially limited by a limiting step 1101 on the lower spindle 11. A disc spring boss 1102 is provided in the middle of the lower spindle 11. The lower end of the disc spring 10 is fixedly connected to the disc spring boss 1102, and the upper part is fixedly connected to the support surface of the lower end of the guide ring 801.

[0041] The limiting sleeve 9 is sleeved outside the disc spring 10, and its upper part is fixedly connected to the straightener 8 by a snap-fit.

[0042] The upper T-shaped groove 701 of the open ring 7 engages with the T-shaped boss 602 of the slip 6, and axially limits the slip 6.

[0043] The locking sleeve 5 is sleeved outside the lower core 11, and the upper end of the locking piece 6 is engaged with the sliding sleeve inclined surface 501 of the locking sleeve 5.

[0044] The upper end of the locking sleeve 5 and the bottom shoe 4 are in surface contact, and the bottom shoe 4 is sleeved on the outside of the lower spindle 11; the top shoe 2 is sleeved on the outside of the lower spindle 11, and two rubber tubes 3 are installed between the bottom shoe 4 and the top shoe 2.

[0045] The upper end of the top shoe 2 is provided with a hydraulic anchor 1, and the hydraulic anchor 1 is provided with a central tube 13 inside, and the hydraulic anchor 1 is connected to the lower top shoe 2 through the central tube 13; as an optional embodiment, the perforation anti-impact downhole packer is characterized in that the bottom of the lower mandrel 11 is provided with a threaded stepped surface 1103, and the lower mandrel 11 and

[0046] The lower drill rods are connected by threads.

[0047] As an optional implementation, the perforation anti-impact downhole packer is characterized in that the guide ring 801 has two axial guide grooves 805, and the lower spindle 11 is provided with two guide sliders 1104.

[0048] As an optional implementation, the perforation anti-impact downhole packer is characterized in that the rubber sleeves 3 are separated by a limiting piece 14.

[0049] As an optional implementation, the perforation anti-impact downhole packer is characterized in that the slip 6 is provided with a friction block 601, and the hydraulic anchor slip 101 is provided with a hydraulic anchor friction block 105.

[0050] As an optional implementation, the perforation anti-impact downhole packer is characterized in that the lower mandrel 11 and the central tube 13 are in clearance fit.

[0051] As an optional implementation, the perforation anti-impact downhole packer is characterized in that the locking sleeve 5 is provided with a V-shaped groove 502.

[0052] The working principle of the anti-impact downhole packer for perforation in this invention is as follows:

[0053] The perforation anti-impact downhole packer provided by this invention has its hydraulic anchor 1 connected to the upper drill pipe and its lower mandrel 11 connected to the lower drill pipe or the lower drill collar when working downhole;

[0054] As the packer reaches the predetermined setting position with the drill string system, the friction blocks on the centralizer friction plates 803 will come into close contact with the casing wall due to the pushing action of the spring plate 802. The drill string is then raised 20-30cm and lowered 50-70cm, and the guide slider 1104 will slide within the axial guide channel 805 to complete the track-changing operation. Then, the packer slips 6 will be radially expanded under the pushing action of the locking sleeve 7, and the friction blocks 601 will come into close contact with the well wall and be fixed by the anchoring mechanism. Furthermore, the top shoe 2 and bottom shoe 4 compress the rubber sleeve 3 to achieve the effect of sealing the annulus. When the downhole pressure is too high, the lower pressure will be transmitted to the inside of the hydraulic anchor 1, and the compression spring 104 will push the hydraulic anchor slips 101 to move radially, further anchoring the packer. The hydraulic anchor fixes the position of the packer through hydraulic action, preventing the packer from moving up and down in the wellbore due to changes in hydraulic column pressure, working pressure, or formation pressure, thus extending the service life of the packer.

[0055] Meanwhile, the outer end of the shock-absorbing rubber sleeve 12 on the lower mandrel 11 will form a bowl-shaped space with the casing wall due to the friction of the casing wall. When perforating downhole, the bowl-shaped space will form a rubber cup seal, which will act on the casing wall to block the impact of the downhole perforation. In addition, the disc spring 10 installed on the lower mandrel 11 will buffer the axial impact and vibration, further preventing the rubber sleeve 3 of the setting mechanism from being affected by downhole impact and ensuring the sealing performance of the rubber sleeve 3. After the setting operation is completed, the drill string is continued to be lifted to make the sealing element contract and release the contact with the well wall. Subsequently, the packer can be taken out of the wellbore along with the tubing string to complete the setting and unsealing operations.

[0056] The foregoing has shown and described the basic principles, main features, and advantages of this patent. Those skilled in the art should understand that this patent is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of this patent. Various changes and modifications can be made to this patent without departing from its spirit and scope, and all such changes and modifications fall within the scope of this patent as claimed. The scope of protection of this patent is defined by the appended claims and their equivalents.

Claims

1. A perforation-resistant downhole packer, characterized in that, The components include a hydraulic anchor (1), a hydraulic anchor slip (101), a fixing clamp (102), a fixing screw (103), a spring (104), a top shoe (2), a rubber sleeve (3), a bottom shoe (4), a locking sleeve (5), a slip (6), an open ring clamp (7), a stabilizer (8), a track changer ring (801), a spring plate (802), a stabilizer friction plate (803), a fixing block (804), a limiting sleeve (9), a disc spring (10), a lower spindle (11), a shock-absorbing rubber sleeve (12), a central tube (13), and a limiting plate (14). The shock-absorbing rubber sleeve (12) is evenly sleeved on the outside of the lower spindle (11) and is axially limited by the limiting step (1101) on the lower spindle (11); the lower spindle (11) is provided with a disc spring boss (1102) in the middle, the lower end of the disc spring (10) is fixedly connected to the disc spring boss (1102), and the upper part is fixedly connected to the support surface of the lower end of the variable track ring (801); The limiting sleeve (9) is sleeved on the outside of the disc spring (10), and its upper part is fixedly connected to the straightener (8) by a snap fastener; the upper T-shaped groove (701) of the open ring hoop (7) cooperates with the T-shaped boss (602) of the slip (6) and axially limits the slip (6); The locking sleeve (5) is sleeved outside the lower spindle (11), and the upper end of the locking piece (6) is engaged with the sliding sleeve inclined surface (501) of the locking sleeve (5); The upper end of the locking sleeve (5) and the bottom shoe (4) are in surface contact, and the bottom shoe (4) is fitted outside the lower spindle (11); the top shoe (2) is fitted outside the lower spindle (11), and two rubber tubes (3) are installed between the bottom shoe (4) and the top shoe (2). The top shoe (2) is provided with a hydraulic anchor (1) at its upper end. The hydraulic anchor (1) is provided with a central tube (13) inside, and the hydraulic anchor (1) is connected to the lower top shoe (2) through the central tube (13). The variable track ring (801) has two axial guide grooves (805), and the lower spindle (11) is provided with two guide sliders (1104). The rubber tubes (3) are separated by limiting pieces (14); The locking sleeve (5) is provided with a V-shaped groove (502).

2. The anti-impact downhole packer for perforation according to claim 1, characterized in that, The bottom of the lower spindle (11) is provided with a threaded stepped surface (1103), and the lower spindle (11) is connected to the lower drill rod by a thread.

3. The anti-impact downhole packer for perforation according to claim 1, characterized in that, The slip (6) is provided with a friction block (601), and the hydraulic anchor slip (101) is provided with a hydraulic anchor friction block (105).

4. The anti-impact downhole packer for perforation according to claim 1, characterized in that, The lower mandrel (11) and the central tube (13) are fitted with a clearance.

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