Anti-impact downhole packer for perforation

Abstract

The invention discloses an anti-impact downhole packer for perforation, and particularly relates to the field of oil and gas well development. A limiting sliding sleeve, a disc spring and a damping rubber cylinder are arranged on the damping mechanism; a centralizing mechanism is arranged at the upper end of the damping mechanism and consists of a centralizer, a spring piece and a centralizer friction plate; a deblocking mechanism is arranged in the righting mechanism and consists of a lower mandrel and a track transfer ring; the setting mechanism is arranged at the upper end of the righting mechanism, the two mechanisms are connected through the orbital transfer ring, and the setting mechanism is provided with an open hoop, a clamping sliding sleeve and a slip; a sealing mechanism is arranged at the upper end of the setting mechanism and consists of two rubber sleeves, and a top shoe and a bottom shoe are arranged above and below the rubber sleeves; an anchoring mechanism is arranged at the upper end of the sealing mechanism, and a hydraulic anchor slip and an elastic limiting structure are arranged at the upper end of the sealing mechanism; when facing underground perforation, the anti-impact underground packer for perforation can be automatically started, the influence of high-strength vibration and impact generated by underground perforation on the performance of the packer is prevented, the setting efficiency of the packer is improved, and the drilling cost is reduced.

Description

Technical Field

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

[0002] With the continuous advancement of oil and gas extraction technology, downhole operations have increasingly higher requirements for the performance of packers. Although existing downhole packers play an important role in oil and gas well stratification, acid fracturing, oil and gas testing, etc., there are still some technical problems that need to be solved. On the one hand, traditional packers have limitations in high pressure resistance, high temperature resistance and corrosion resistance. During downhole perforation operations, the sealing performance of the packer will be affected by downhole impact, which to a certain extent limits its use in complex well conditions. Especially in the process of exploitation of deep oil and gas reservoirs, the high temperature, high pressure and corrosive media at the bottom of the well pose a higher challenge to the long-term stability and sealing performance of the packer. On the other hand, the existing packers are complicated to operate and have low operating efficiency during the setting and recovery process, and are easily affected by wellbore conditions, such as irregularities of the well wall and changes in the well diameter, which may lead to unstable setting or difficulty in recovery of the packer. At present, the packers on the market are often more complex in structural design, which not only increases the manufacturing cost, but also easily fails during downhole operations, affecting operational safety.

[0003] The existing Chinese patent document application number CN 202411077949.1 discloses an external pipe packer for cementing, including a packer body, the packer body includes a center pipe, an upper joint, a pressure seat, a tile seat, a plurality of slips and two rubber cylinders, wherein the center pipe includes an upper pipe and a lower pipe, the upper pipe is fixedly connected to the upper joint, the lower pipe is fixedly connected to the tile seat, and a clamping groove is formed on one side of the upper part of the slip close to the tile seat; it also includes a plurality of limiting mechanisms, and the plurality of limiting mechanisms are arranged in an array uniformly at equal angles along the circumferential direction of the pressure seat, the center pipe includes an upper pipe and a lower pipe, each limiting mechanism includes a limiting shaft, a limiting spring and an anti-slip mechanism, one end of the limiting shaft is slidably connected to the upper pipe, and the other end is fixedly connected to the lower pipe, the limiting spring is sleeved on the outside of the limiting shaft, the two ends of the limiting spring are respectively fixedly connected to the upper pipe and the lower pipe, and the anti-slip mechanism is connected to the pressure seat. The device prevents the slip from being further expanded when the rubber cylinder is expanded after the slip is tightly stretched against the inner side of the pipe wall, thereby causing damage to the pipe wall.

[0004] Existing Chinese patent document CN 202411065118.2 discloses an adjustable oil well packer for oil development, including a shell, a sealing pressure plate, a sealing rubber block, and a regulating component, wherein the regulating component includes a first driving rod, a driving disc, a clutch disc, a control disc, and a second driving rod, wherein the clutch disc is configured to be composed of a plurality of fan-shaped discs, and the plurality of fan-shaped discs can independently move vertically. When the sealing rubber block is deformed to fit the inner wall of the oil pipe, if the driving disc continues to rotate, and the force tooth ring or the latch teeth are locally worn, or debris is stuck between the force tooth ring and the latch teeth, then the plurality of fan-shaped discs that can independently move vertically can independently move according to the above situation, disperse the local pressure, and extend the service life of the driving disc or the fan-shaped disc, and when a fan-shaped disc or the latch teeth is damaged, it can be replaced separately, thereby reducing maintenance costs.

[0005] However, the above patent documents still have the following defects in the implementation process:

[0006] The above methods are limited by the complex underground environment when used, and the device itself has a complex structure and control system, cannot withstand severe impact and vibration underground, is difficult to adapt to the special underground environment, and has high cost of use.

[0007] Therefore, in order to address the problem that downhole perforating causes the packer to not operate effectively, this patent proposes an anti-shock downhole packer for perforating, which aims to improve the packer's explosion-proof, anti-shock, anti-vibration, and pressure-resistant performance under complex well conditions by improving the packer's structural design, material selection, and operating mechanism, simplify the operating process, improve operating efficiency, and reduce manufacturing costs, so as to meet the high standards and strict requirements of modern oil and gas well exploitation. Summary of the invention

[0008] The main purpose of the present invention is to provide a shock-proof downhole packer for perforating, which can effectively prevent the influence of high-intensity shock waves and vibrations during downhole perforating on the sealing efficiency of the packer, and can adaptively respond to downhole perforating shocks; improve the explosion-proof, shock-proof, shock-resistant and pressure-resistant performance of the packer under complex well conditions, simplify the operation process, improve the operating efficiency, and reduce the manufacturing cost at the same time, so as to meet the high standards and strict requirements of modern oil and gas well exploitation.

[0009] To achieve the above object, the technical solution adopted by the present invention is:

[0010] The present invention provides an anti-shock downhole packer for perforating, comprising a hydraulic anchor, a fixing screw, a spring, a fixing splint, a top shoe, a rubber tube, a bottom shoe, a positioning sleeve, a slip, an open hoop, a track change ring, a spring sheet, a centralizer friction sheet, a fixing block, a centralizer, a limiting sleeve, a disc spring, a lower mandrel, a shock-absorbing rubber tube, a hydraulic anchor slip, a central tube, and a limiting sheet, wherein:

[0011] The shock-absorbing rubber tube is evenly sleeved on the outside of the lower spindle, and is axially limited by the limiting step on the lower spindle; a disc spring boss is provided in the middle of the lower spindle, the lower part of the disc spring is fixedly connected to the disc spring boss, and the upper part is fixedly connected to the supporting surface of the lower end of the track change ring;

[0012] The limit sliding sleeve is sleeved on the outside of the disc spring, and the upper part of the limit sliding sleeve is fixedly connected to the centralizer by a buckle;

[0013] The T-shaped groove on the upper part of the open hoop cooperates with the T-shaped boss of the slip and limits the slip in the axial direction;

[0014] The locking sleeve is sleeved on the outside of the lower spindle, and the upper end of the slip cooperates with the inclined surface of the locking sleeve;

[0015] The upper end of the positioning sliding sleeve is in surface contact with the bottom shoe, and the bottom shoe cover is arranged outside the lower spindle; the top shoe cover is arranged outside the lower spindle, and two rubber cylinders are installed between the bottom shoe and the top shoe;

[0016] A hydraulic anchor is arranged at the upper end of the top shoe, a central tube is arranged inside the hydraulic anchor, and the hydraulic anchor is connected to the lower top shoe through the central tube.

[0017] Optionally or preferably, a threaded step surface is provided at the bottom of the lower mandrel, and the lower mandrel is threadedly connected to the lower drill rod.

[0018] Optionally or preferably, the track change ring has two axial guide grooves, and the lower spindle is provided with two guide sliders.

[0019] Optionally or preferably, the rubber cylinders are separated by limiting plates.

[0020] Optionally or preferably, the slip is provided with a friction block, and the hydraulic anchor slip is provided with a hydraulic anchor friction block.

[0021] Optionally or preferably, there is a clearance fit between the lower mandrel and the center tube.

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

[0023] When the anti-shock downhole packer for perforating provided by the present invention works downhole, its hydraulic anchor is connected to the upper drill pipe, and the lower mandrel is connected to the lower drill pipe or the lower drill collar; the packer reaches the predetermined setting position along with the drill string system, and due to the pushing effect of the spring sheet, the friction block on the friction plate of the stabilizer will be in close contact with the casing wall; the pipe string is lifted up by 20-30cm, and then the drill string is lowered by 50-70cm, and the guide slider will slide in the axial guide groove to complete the track changing operation; then the packer slip will slide in the locking position The hydraulic anchor is pushed by the sleeve and radially expands, and the friction block is in close contact with the well wall and fixed by the anchoring mechanism; further, the top shoe and the bottom shoe compress the rubber tube to achieve the effect of sealing the annulus; when the downhole pressure is too large, 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 to further anchor the packer. The hydraulic anchor fixes the position of the packer through hydraulic action to prevent the packer from moving up and down in the wellbore due to changes in liquid column pressure, operating pressure or formation pressure, thereby extending the service life of the packer.

[0024] At the same time, the outer end of the shock-absorbing rubber tube on the lower mandrel 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 leather cup seal, acting on the casing wall to block the impact of perforating downhole; and the disc spring installed on the mandrel will buffer the axial impact and vibration, further preventing the rubber tube of the sealing mechanism from being affected by the impact downhole, thereby ensuring the sealing of the rubber tube; after the sealing operation is completed, continue to lift the drill string to shrink the sealing element and release the contact with the well wall; then, the packer can be taken out of the wellbore together with the tubing to complete the sealing and unsealing operations.

[0025] In summary, the impact-proof downhole packer for perforating of the present invention has the function of buffering downhole perforating impact and vibration, absorbing the shock wave energy generated during perforating, and reducing damage to the packer and its sealing elements; the impact-proof packer can resist the instantaneous high pressure generated by perforating while maintaining the sealing performance; it can isolate the perforated layer from other layers, prevent the high-pressure fluid in the perforating operation or the debris generated by the perforating from entering other layers, ensure the sealing efficiency of the packer, and ensure the accuracy and safety of the operation.

[0026] After adopting the above technical solution, compared with the prior art, the embodiment of the present invention has at least the following beneficial effects:

[0027] 1. The present invention has high reliability. By arranging the shock-absorbing rubber tube and the casing wall to form a bowl-shaped space, the perforation layer is isolated and the impact energy is absorbed, thereby reducing the risk in the perforation operation and improving the safety of the underground operation.

[0028] 2. The present invention can effectively resist perforation impact, buffer axial vibration, and reduce packer damage and operation interruption caused by perforation impact by arranging a disc spring on the lower mandrel. The anti-impact downhole packer helps to improve the overall operation efficiency.

[0029] 3. The present invention can effectively isolate different production layers or water injection layers by setting slips and hydraulic anchors to prevent fluids from flowing between layers, thereby improving the extraction efficiency or water injection efficiency of fluids such as oil, gas and water; the use of a track change ring simplifies the sealing operation mechanism, making the sealing and recovery process faster and reducing the operation time and labor intensity. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It 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 set;

[0032] Figure 3 It is a schematic diagram of the overall cross-sectional structure of the present invention when it is not set;

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

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

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

[0036] In the figure: 1, hydraulic anchor; 101, hydraulic anchor slip; 102, fixing splint; 103, fixing screw; 104, spring; 105, hydraulic anchor friction block; 2, top shoe; 3, rubber tube; 4, bottom shoe; 5, positioning sleeve; 501, sleeve slope; 502, V-shaped slide; 6, slip; 601, friction block; 602, T-shaped boss; 7, open hoop; 701, T-shaped slot; 8 , centralizer; 801, track change ring; 802, spring sheet; 803, centralizer friction plate; 804, fixing block; 805, axial guide groove; 9, limiting sleeve; 10, disc spring; 11, lower spindle; 1101, limiting step; 1102, disc spring boss; 1103, threaded step surface; 1104, guide slider; 12, shock-absorbing rubber tube; 13, center tube; 14, limiting plate. DETAILED DESCRIPTION

[0037] In order to make the technical means, creative features, objectives and effects of this patent easy to understand, the present invention is further described below in conjunction with specific implementation methods. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other implementation methods obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0038] like Figures 1 to 6As shown:

[0039] The present invention provides 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 splint 102, a top shoe 2, a rubber tube 3, a bottom shoe 4, a positioning sleeve 5, a slip 6, an open hoop 7, a track change ring 801, a spring sheet 802, a centralizer friction sheet 803, a fixing block 804, a centralizer 8, a limiting sleeve 9, a disc spring 10, a lower spindle 11, a shock-absorbing rubber tube 12, a hydraulic anchor slip 101, a central tube 13, and a limiting sheet 14, wherein:

[0040] The shock-absorbing rubber tube 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; 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 supporting surface of the lower end of the track change ring 801;

[0041] The limiting sliding sleeve 9 is sleeved on the outside of the disc spring 10, and the upper part of the limiting sliding sleeve 9 is fixedly connected to the centralizer 8 by a buckle;

[0042] The T-shaped groove 701 on the upper part of the open hoop 7 cooperates with the T-shaped boss 602 of the slip 6 to limit the axial position of the slip 6;

[0043] The locking sleeve 5 is sleeved on the outside of the lower core 11, and the upper end of the slip 6 is matched with the sleeve inclined surface 501 of the locking sleeve 5;

[0044] The upper end of the positioning sleeve 5 is in surface contact with the bottom shoe 4, 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 cylinders 3 are installed between the bottom shoe 4 and the top shoe 2;

[0045] A hydraulic anchor 1 is provided at the upper end of the top shoe 2, a central tube 13 is provided inside the hydraulic anchor 1, and the hydraulic anchor 1 is connected to the lower top shoe 2 through the central tube 13;

[0046] As an optional embodiment, the anti-shock downhole packer for perforating is characterized in that a threaded step surface 1103 is provided at the bottom of the lower mandrel 11, and the lower mandrel 11 is threadedly connected to the lower drill pipe.

[0047] As an optional embodiment, the anti-shock downhole packer for perforating is characterized in that the track change ring 801 has two axial guide grooves 805 , and the lower mandrel 11 is provided with two guide sliding blocks 1104 .

[0048] As an optional implementation, the anti-shock downhole packer for perforating is characterized in that the rubber tubes 3 are separated by limit plates 14.

[0049] As an optional embodiment, the anti-shock downhole packer for perforating 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 embodiment, the anti-shock downhole packer for perforating is characterized in that there is a clearance fit between the lower mandrel 11 and the central pipe 13 .

[0051] As an optional implementation, the anti-shock downhole packer for perforating is characterized in that a V-shaped sliding groove 502 is provided on the locking sliding sleeve 5 .

[0052] The working principle of a downhole anti-shock packer for perforating in the present invention is as follows:

[0053] When the anti-shock downhole packer for perforating provided by the present invention is working downhole, its hydraulic anchor 1 is connected to the upper drill pipe, and the lower mandrel 11 is connected to the lower drill pipe or the lower drill collar; the packer reaches the predetermined setting position along with the drill string system, and due to the pushing effect of the spring sheet 802, the friction block on the friction plate 803 of the stabilizer will be in close contact with the casing wall; the pipe string is lifted up 20-30cm, and then the drill string is lowered 50-70cm, and the guide slider 1104 will slide in the axial guide groove 805 to complete the track change operation; then the packer slip 6 will be in the slip The hydraulic anchor 102 is pushed forward by the sliding sleeve 7 and radially expands, and the friction block 601 is in close contact with the well wall and fixed by the anchoring mechanism; further, the top shoe 2 and the bottom shoe 4 compress the rubber sleeve 3 to achieve the effect of sealing the annulus; when the downhole pressure is too large, the lower pressure will be transmitted to the inside of the hydraulic anchor 1, and the compression spring 104 will push the hydraulic anchor slip 101 to move radially, thereby 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 liquid column pressure, operating pressure or formation pressure, thereby extending the service life of the packer.

[0054] At the same time, the outer end of the shock-absorbing rubber tube 12 on the lower core shaft 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 leather cup seal, acting on the casing wall to block the impact of perforating downhole; and the disc spring 10 installed on the lower core shaft 11 will buffer the axial impact and vibration, further prevent the rubber tube 3 of the sealing mechanism from being affected by the impact downhole, and ensure the sealing of the rubber tube 3; after the sealing operation is completed, continue to lift the drill string to shrink the sealing element and release the contact with the well wall; then, the packer can be taken out from the wellbore together with the pipe string to complete the sealing and unsealing operations.

[0055] The above shows and describes the basic principles and main features of this patent and the advantages of this patent. Those skilled in the art should understand that this patent is not limited to the above embodiments. The above embodiments and descriptions are only for explaining the principles of this patent. Without departing from the spirit and scope of this patent, this patent will have various changes and improvements, which fall within the scope of this patent. The scope of protection claimed by this patent is defined by the attached claims and their equivalents.

Claims

1. A downhole anti-shock packer for perforating, characterized in that: The invention comprises a hydraulic anchor (1), a hydraulic anchor slip (101), a fixing splint (102), a fixing screw (103), a spring (104), a top shoe (2), a rubber tube (3), a bottom shoe (4), a positioning sleeve (5), a slip (6), an open hoop (7), a centralizer (8), a track change ring (801), a spring sheet (802), a centralizer friction sheet (803), a fixing block (804), a limiting sleeve (9), a disc spring (10), a lower spindle (11), a shock-absorbing rubber tube (12), a center tube (13), and a limiting sheet (14), wherein: The shock-absorbing rubber tube (12) is evenly sleeved on the outside of 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 supporting surface of the lower end of the track change ring (801); The limiting sliding sleeve (9) is sleeved on the outside of the disc spring (10), and the upper part of the limiting sliding sleeve is fixedly connected to the centralizer (8) by a buckle; The T-shaped groove (701) on the upper part of the open hoop (7) cooperates with the T-shaped boss (602) of the slip (6) to limit the axial position of the slip (6); The locking sleeve (5) is sleeved on the outside of the lower spindle (11), and the upper end of the slip (6) cooperates with the sleeve inclined surface (501) of the locking sleeve (5); The upper end of the locking sleeve (5) is in surface contact with the bottom shoe (4), 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 sleeves (3) are installed between the bottom shoe (4) and the top shoe (2); A hydraulic anchor (1) is provided at the upper end of the top shoe (2), a central tube (13) is provided inside the hydraulic anchor (1), and the hydraulic anchor (1) is connected to the lower top shoe (2) via the central tube (13).

2. The anti-shock downhole packer for perforation according to claim 1, characterized in that: The bottom of the lower mandrel (11) is provided with a threaded step surface (1103), and the lower mandrel (11) is threadedly connected to the lower drill rod.

3. The anti-shock downhole packer for perforation according to claim 1, characterized in that: The track change ring (801) is provided with two axial guide grooves (805), and the lower spindle (11) is provided with two guide sliding blocks (1104).

4. The anti-shock downhole packer for perforation according to claim 1, characterized in that: The rubber cylinders (3) are separated by limiting plates (14).

5. The anti-shock 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).

6. The anti-shock downhole packer for perforation according to claim 1, characterized in that: The lower mandrel (11) and the center tube (13) are clearance-fitted.

7. The anti-shock downhole packer for perforation according to claim 1, characterized in that: The locking sliding sleeve (5) is provided with a V-shaped sliding groove (502).

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