A multi-stage plunger downhole placement device

Abstract

This invention relates to the field of oil and gas production technology for unconventional oil and gas reservoirs such as petroleum and natural gas, and particularly to a downhole placement device for multi-stage plungers. This invention provides a downhole placement device for multi-stage plungers. When the locking wire contacts and springs open the tubing coupling, a right-angled step extends into the tubing coupling and engages with it, forming the first anchoring. When the center rod moves towards the locking wire, the cup moves along the conical surface of the cone to abut against the inner wall of the tubing, forming the first seal. When the center rod moves towards the locking wire, the end of the drain section away from the slip connector abuts against the rubber sleeve, which, under pressure, abuts against the inner wall of the tubing, forming the second seal. When the slip expands along the conical slide away from the slip axis until the slip engages with the inner wall of the tubing, forming the second anchoring. The multi-stage plunger placement device of this invention has a double anchoring mechanism, a double sealing mechanism, high anchoring force, good sealing effect, and stable performance.

Description

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[0001] The present invention relates to the technical field of oil and gas production in unconventional oil and gas reservoirs such as oil and natural gas, and particularly relates to a downhole setting tool for a multi-stage plunger. Background Art

[0002] The multi-stage plunger drainage gas production process has the advantages of significantly reducing the starting pressure of the plunger and improving the liquid drainage efficiency of the plunger, etc., and has a broad application prospect. The downhole setting tool supporting the multi-stage plunger drainage gas production process needs to withstand the bidirectional impact of the upper and lower plungers. The central flow channel of the setting tool has a check valve and seals the annular space between it and the tubing to achieve the purpose of preventing the accumulated liquid from flowing back. The setting tool used in the conventional plunger gas lift process is prone to unclamping and upward movement under the condition of withstanding the bidirectional impact of the upper and lower plungers, resulting in the failure of the process operation. Summary of the Invention

[0003] The purpose of the present invention is to provide a downhole setting tool for a multi-stage plunger to solve the problem that the setting tool used in the current conventional plunger gas lift process is prone to unclamping and upward movement under the condition of withstanding the bidirectional impact of the upper and lower plungers, resulting in the failure of the process operation.

[0004] To solve the above technical problems, the technical solution provided by the present invention is as follows:

[0005] A downhole setting tool for a multi-stage plunger, comprising: a cone, a slip, a slip connecting body, a drainage nipple, a steel ball, a central rod, a rubber cylinder, a cone body, a cup leather, an inner washer, an outer ring, an elastic claw and a locking wire;

[0006] The slip, the slip connecting body, the drainage nipple and the central rod are connected in sequence;

[0007] The cone is inserted into the slip and the slip connecting body and extends into the drainage nipple. The cone is slidably connected to the drainage nipple. A conical slideway is provided at one end of the cone away from the drainage nipple, and the slip can move along the conical slideway;

[0008] One end of the central rod is inserted into the drainage nipple, and the steel ball abuts against the port of the central rod close to the drainage nipple so that the liquid in the inner flow channel of the central rod can run upward and cannot flow back from the inner of the central rod;

[0009] The rubber cylinder, the cone body, the cup leather, the inner washer and the outer ring are sleeved on the outside of the central rod in sequence in the direction away from the drainage nipple and can slide relative to the central rod. The outer ring is threadedly connected to the elastic claw, and one end of the central rod away from the steel ball extends into the elastic claw and can slide relative to the elastic claw;

[0010] The elastic claw is provided with a right-angle step for engaging with the tubing coupling. The elastic claw is locked by the locking wire so that the right-angle step is not engaged with the tubing coupling. When the locking wire contacts the tubing coupling and springs open, the locking wire releases the elastic claw, and the right-angle step extends into the tubing coupling and engages with it, thus forming the first anchoring.

[0011] When the center rod moves toward the locking wire, the cup can move along the conical surface of the cone to abut against the inner wall of the oil pipe, thus forming the first seal.

[0012] When the center rod moves toward the locking wire, the end of the drain section away from the slip connector can abut against the rubber sleeve. Under pressure, the rubber sleeve abuts against the inner wall of the oil pipe, thus forming a second seal.

[0013] When the slip expands along the conical slide away from the slip axis until the slip engages with the inner wall of the oil pipe, a second anchoring is formed.

[0014] Furthermore, the multi-stage plunger downhole positioning device also includes an upper retrieval head, an upper support rod, an upper shock-absorbing spring, and an upper support seat;

[0015] The upper retrieval head is threadedly connected to the upper support rod, and the upper support rod extends into the upper support seat and can move relative to the upper support seat.

[0016] The upper shock-absorbing spring is sleeved on the outside of the upper support rod. One end of the upper shock-absorbing spring is connected to the upper retrieval head, and the other end is connected to the upper support base.

[0017] The upper support is connected to the conical body.

[0018] Furthermore, the multi-stage plunger downhole positioning device also includes a lower support base, a lower shock-absorbing spring, a lower support rod, and a lower retrieval head;

[0019] The lower retrieval head is threadedly connected to the lower support rod, and the lower support rod extends into the lower support seat and can move relative to the lower support seat;

[0020] The lower shock-absorbing spring is sleeved on the outside of the lower support rod. One end of the lower shock-absorbing spring is connected to the lower retrieval head, and the other end is connected to the lower support base.

[0021] The lower end of the elastic claw is connected to the lower support seat by a thread.

[0022] Furthermore, the slip connector has a through hole, and the slip and the slip connector are connected through the through hole.

[0023] Furthermore, the cone-shaped body is provided with an upper limit block, and a sliding groove is provided inside the drainage section, with the limit block slidably connected to the sliding groove.

[0024] Furthermore, the multi-stage plunger downhole positioning device also includes an elastic external clamp;

[0025] The elastic outer clamp is fitted onto the outside of the clamp.

[0026] Furthermore, the drainage section is provided with a drainage hole for drainage.

[0027] Furthermore, the multi-stage plunger downhole positioning device also includes a retaining ring;

[0028] The inner washer is threadedly connected to the outer ring and forms a retaining groove, with the outer ring of the retaining spring extending into the retaining groove.

[0029] Furthermore, the center rod is provided with an upper groove and a lower groove for engaging with the inner ring of the retaining spring.

[0030] Furthermore, the central rod is provided with a lower step block, and the elastic claw is provided with a chamfer for abutting against the lower step block.

[0031] In summary, the technical effects achieved by this invention are as follows:

[0032] When the locking wire contacts and springs open the tubing coupling, the elastic claw releases its lock, and the right-angle step extends into the tubing coupling and engages with it, forming the first anchoring. When the center rod moves towards the locking wire, the rubber cup moves along the conical surface of the cone to abut against the inner wall of the tubing, forming the first seal. When the center rod moves towards the locking wire, the end of the drain section away from the slip connector abuts against the rubber sleeve, which, under pressure, abuts against the inner wall of the tubing, forming the second seal. When the slip expands along the conical slide away from the slip axis until it engages with the inner wall of the tubing, the second anchoring is formed. The multi-stage plunger placement device of the present invention has a double anchoring mechanism and a double sealing mechanism, with large anchoring force, good sealing effect and stable performance. It solves the problem that the placement device used in the conventional plunger gas lift process is prone to disengagement and upward movement under the condition of being subjected to bidirectional impact from the upper and lower plungers, which leads to process failure. Attached Figure Description

[0033] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0034] Figure 1 This is a schematic diagram of the structure of a multi-stage plunger downhole placement device provided in an embodiment of the present invention;

[0035] Figure 2 for Figure 1 An enlarged view of position A in the middle;

[0036] Figure 3 for Figure 1 An enlarged view of position B in the middle;

[0037] Figure 4 for Figure 1 An enlarged view of position C in the middle;

[0038] Figure 5 for Figure 1 An enlarged view of position D in the middle;

[0039] Figure 6 for Figure 1 An enlarged view of position E in the middle;

[0040] Figure 7 This is a schematic diagram of the structure of the locator connector;

[0041] Figure 8 This is a structural diagram of the KAVO connector from another angle;

[0042] Figure 9 This is a schematic diagram of a cone-shaped structure;

[0043] Figure 10 This is a schematic diagram of the drainage section;

[0044] Figure 11 This is a schematic diagram of the central rod.

[0045] Figure 12 This is a schematic diagram of the seat setting state provided in an embodiment of the present invention;

[0046] Figure 13 for Figure 12 Enlarged diagram of position F in the middle;

[0047] Figure 14 for Figure 12 Enlarged diagram of position G in the middle;

[0048] Figure 15 for Figure 12 Enlarged view of position H in the middle;

[0049] Figure 16 for Figure 12 Enlarged schematic diagram of position I in the middle;

[0050] Figure 17 for Figure 12 Enlarged diagram of position J in the middle;

[0051] Figure 18 for Figure 12 Enlarged view of position K in the middle;

[0052] Figure 19 This is a schematic diagram of the locking wire structure.

[0053] Icons: 1-Upper retrieval head; 2-Upper support rod; 3-Upper shock absorber spring; 4-Upper support seat; 5-Conical body; 51-Upper limit block; 52-Conical slide; 6-Clip; 7-Elastic outer clamp; 8-Clip connector; 81-Through hole; 9-Drainage short section; 91-Slide groove; 92-Drainage hole; 10-Steel ball; 11-Center rod; 111-Upper groove; 112-Lower groove; 113-Lower step block; 12-Rubber sleeve; 13-Conical body; 14-Leather cup; 15-Inner washer; 16-Snap ring; 17-Outer ring; 171-Snap groove; 18-Elastic claw; 181-Right angle step; 182-Chamfer; 19-Locking wire; 20-Lower support seat; 21-Lower shock absorber spring; 22-Lower support rod; 23-Lower retrieval head. Detailed Implementation

[0054] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0055] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0056] The following detailed description of some embodiments of the present invention is provided in conjunction with the accompanying drawings. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0057] This invention provides a multi-stage plunger downhole placement device, comprising: a conical body 5, slips 6, slip connector 8, drainage sub 9, steel ball 10, center rod 11, rubber sleeve 12, conical body 13, cup 14, inner washer 15, outer ring 17, elastic claw 18, and locking wire 19; the slips 6, slip connector 8, drainage sub 9, and center rod 11 are connected sequentially; the conical body 5 is inserted into the slips 6 and slip connector 8, and extends into the drainage sub 9, the conical body 5 is slidably connected to the drainage sub 9, and the conical body 5 is located away from the drainage sub 9. One end is provided with a tapered slide 52, and the slip 6 can move along the tapered slide 52; one end of the center rod 11 is inserted into the drain section 9, and the steel ball 10 abuts against the port of the center rod 11 near the drain section 9, so that the liquid in the flow channel inside the center rod 11 can run upward and cannot fall back from the center rod 11; the rubber sleeve 12, cone 13, cup 14, inner washer 15 and outer ring 17 are sequentially sleeved on the outside of the center rod 11 in the direction away from the drain section 9, and can slide relative to the center rod 11; the outer ring 17 is threaded to the elastic claw 18. Next, the end of the center rod 11 away from the steel ball 10 extends into the elastic claw 18 and can slide relative to the elastic claw 18; the elastic claw 18 is provided with a right-angle step 181 for engaging with the oil pipe coupling. The elastic claw 18 is locked by the locking wire 19 so that the right-angle step 181 is not engaged with the oil pipe coupling. When the locking wire 19 contacts the oil pipe coupling and springs open, the locking wire 19 releases the locking of the elastic claw 18, and the right-angle step 181 extends into the oil pipe coupling and engages with the oil pipe coupling, thus forming the first anchoring; when the center rod 11 moves towards When the piston cup 14 moves toward the locking wire 19, it can move along the conical surface of the cone 13 to abut against the inner wall of the oil pipe, thus forming the first seal. When the center rod 11 moves toward the locking wire 19, the end of the drain stub 9 away from the slip connector 8 can abut against the rubber sleeve 12. Under pressure, the rubber sleeve 12 abuts against the inner wall of the oil pipe, thus forming the second seal. When the slip 6 expands along the conical slide 52 away from the axis of the slip 6 until the slip 6 engages with the inner wall of the oil pipe, thus forming the second anchoring.

[0058] The multi-stage plunger placement device of the present invention has a double anchoring mechanism and a double sealing mechanism, with large anchoring force, good sealing effect and stable performance. It solves the problem that the placement device used in the conventional plunger gas lift process is prone to disengagement and upward movement under the condition of being subjected to bidirectional impact from the upper and lower plungers, which leads to process failure.

[0059] The following combination Figures 1-19 The structure and shape of the multi-stage plunger downhole placement device provided in this embodiment are described in detail.

[0060] Regarding the shape and structure of the upper salvage head 1, upper support rod 2, upper shock-absorbing spring 3, and upper support base 4, in detail:

[0061] Reference Figure 1 and Figure 2 The upper retrieval head 1 and the upper support rod 2 are connected by threads. The upper support rod 2 extends into the upper support seat 4 and can move relative to the upper support seat 4. The upper shock-absorbing spring 3 is sleeved on the outside of the upper support rod 2. One end of the upper shock-absorbing spring 3 is connected to the upper retrieval head 1, and the other end is connected to the upper support seat 4. The upper support rod 2 and the upper support seat 4 are limited by the lower step on the upper support rod 2. By compressing the upper shock-absorbing spring 3, the upper support rod 2 can extend and retract within the upper support seat 4. The upper retrieval head 1, the upper support rod 2, the upper shock-absorbing spring 3, and the upper support seat 4 constitute the upper shock-absorbing mechanism, which can effectively buffer the impact of the plunger falling rapidly from the top onto the landing device.

[0062] Regarding the shape and structure of the conical body 5, the slip 6, the elastic external clamp 7, the slip connector 8, and the drainage stub 9, in detail:

[0063] Reference Figure 1 and Figure 3 The slip 6, slip connector 8, drain stub 9 and center rod 11 are connected in sequence from top to bottom. The conical body 5 is inserted into the slip 6 and slip connector 8 and extends into the drain stub 9. The conical body 5 is slidably connected to the drain stub 9. A conical slide 52 is provided at the end of the conical body 5 away from the drain stub 9. The slip 6 can move along the conical slide 52. The elastic outer clamp 7 is sleeved on the outside of the slip 6.

[0064] Specifically, the conical body 5 is located below the upper support 4, and the upper support 4 and the conical body 5 are connected by threads, as shown in the reference. Figure 7 and Figure 8 The slip connector 8 has evenly distributed through holes 81. The slip 6 is connected to the slip connector 8 through the through holes 81, and the bottom end of the slip 6 extends into and connects to the through hole 81. The slip connector 8 is connected to the drain stub 9 by threads. The conical body 5 can run within the central channel between the slip connector 8 and the drain stub 9, as shown in the reference. Figure 9 and Figure 10 The conical body 5 is equipped with an upper limit block 51, and the drain section 9 has a groove 91. The upper limit block is slidably connected to the groove 91, and the upper limit block 51 is limited within the groove 91. The slip 6 is tightly attached to the conical body 5 by the action of the elastic outer clamp 7. During the movement of the conical body 5, the slip 6 can run along the conical slide 52.

[0065] Regarding the shape and structure of the steel ball 10 and the center rod 11, in detail:

[0066] Reference Figure 1 and Figure 4 One end of the center rod 11 is inserted into the drain section 9, and the steel ball 10 abuts against the port of the center rod 11 near the drain section 9, so that the liquid in the flow channel inside the center rod 11 can run upward and cannot fall back from the center rod 11.

[0067] Specifically, the drain section 9 is threadedly connected to the center rod 11. The upper end of the center rod 11 is chamfered and forms a check valve with the steel ball 10, ensuring that the liquid in the flow channel inside the center rod 11 can flow upward and cannot fall back from the center rod 11. The drain section 9 is designed with a drain hole 92, through which the liquid flowing from bottom to top inside the center rod 11 can be discharged.

[0068] Regarding the shape and structure of the rubber sleeve 12, cone 13, leather cup 14, inner washer 15, retaining spring 16, outer ring 17, elastic claw 18, and locking wire 19, in detail:

[0069] Reference Figure 1 and Figure 5 The rubber sleeve 12, cone 13, cup 14, inner washer 15 and outer ring 17 are sequentially sleeved on the outside of the central rod 11 in the direction away from the drain section 9, and can slide relative to the central rod 11. The outer ring 17 is threadedly connected to the elastic claw 18. The end of the central rod 11 away from the steel ball 10 extends into the elastic claw 18 and can slide relative to the elastic claw 18.

[0070] The elastic claw 18 is provided with a right-angle step 181 for engaging with the oil pipe coupling. The elastic claw 18 is locked by the locking wire 19 so that the right-angle step 181 is not engaged with the oil pipe coupling.

[0071] When the locking wire 19 contacts and springs open the oil pipe coupling, the locking wire 19 releases the locking of the elastic claw 18, and the right-angle step 181 extends into the oil pipe coupling and engages with the oil pipe coupling, thus forming the first anchoring. When the slip 6 expands along the conical slide 52 in a direction away from the axis of the slip 6 until the slip 6 engages with the inner wall of the oil pipe, thus forming the second anchoring.

[0072] When the center rod 11 moves towards the locking wire 19, the cup 14 can move along the conical surface of the cone 13 to abut against the inner wall of the oil pipe, thus forming the first seal. When the center rod 11 moves towards the locking wire 19, the end of the drain section 9 away from the slip connector 8 can abut against the rubber sleeve 12. Under pressure, the rubber sleeve 12 abuts against the inner wall of the oil pipe, thus forming the second seal. Specifically, both the cone 13 and the cup 14 have inclined surfaces. The inclined surfaces of the cone 13 and the cup 14 are arranged opposite to each other. The rubber sleeve 12 and the cup 14 are compressed and deformed during the downward movement of the center rod 11, forming a seal by tightly contacting the inner wall of the oil pipe. (Refer to...) Figure 11 The lower end of the center rod 11 is designed with a lower step block 113, which can also serve as a limit for the vertical movement of the center rod 11. The elastic claw 18 is provided with a chamfer 182 for abutting against the lower step block 113. The outer ring 17 is connected to the elastic claw 18 by a thread. (Refer to...) Figure 1Before the tool is inserted into the well, the elastic claw 18 can be locked together by the locking wire 19. The structure of the locking wire 19 is as follows: Figure 19 As shown, in this embodiment, the elastic claw 18 is provided with a pin, and the locking wire 19 is hinged to the pin. The bent part of the locking wire 19 is engaged with another pin so that the locking wire 19 locks the elastic claw 18.

[0073] In an optional implementation, refer to Figure 18 The chamfer 182 of the elastic claw 18 is a bevel and has a horizontal edge for limiting, so as to prevent the center rod 11 from continuing to move downward.

[0074] In an optional embodiment, this embodiment also includes a retaining spring 16, which is sleeved on the central rod 11 and engages with the upper groove 111 and lower groove 112 of the central rod 11 to lock the central rod 11. The inner washer 15 is threadedly connected to the outer ring 17 and forms a retaining groove 171. The outer ring of the retaining spring 16 extends into the retaining groove 171, and the inner ring of the retaining spring 16 extends into the groove of the central rod 11.

[0075] Regarding the shape and structure of the lower support base 20, the lower shock-absorbing spring 21, the lower support rod 22, and the lower retrieval head 23, in detail:

[0076] Reference Figure 1 and Figure 6 The lower retrieval head 23 is threadedly connected to the lower support rod 22, which extends into the lower support seat 20 and can move relative to it. A lower damping spring 21 is sleeved on the outside of the lower support rod 22, with one end connected to the lower retrieval head 23 and the other end connected to the lower support seat 20. The lower end of the elastic claw 18 is threadedly connected to the lower support seat 20. The lower support seat 20, lower damping spring 21, lower center rod 11, and lower retrieval head 23 constitute the lower damping mechanism, mitigating the impact of the lower plunger on the landing device.

[0077] The working process of the multi-stage plunger downhole deployment device provided in this embodiment is as follows:

[0078] I. The deployment process of the multi-stage plunger downhole deployment device provided in this embodiment:

[0079] The delivery string of the multi-stage plunger setter consists of, from top to bottom: steel wire, rope cap, weight bar, vibrator, delivery bucket, and setter. Among them, the steel wire, rope cap, weight bar, vibrator, and delivery bucket are all standard steel wire operation tools.

[0080] First, lock the two elastic claws 18 of the landing device together using the locking wire 19 (as shown). Figure 1 As shown, the tool will not get stuck in the tubing coupling during the well entry process, and the placement device will enter the well smoothly and stably without being limited by the entry speed.

[0081] The steel wire, rope cap, weight bar, shock absorber, delivery bucket, and landing device are connected in sequence to form a landing device steel wire operation delivery pipe string.

[0082] II. Anchoring and sealing process of the multi-stage plunger downhole setter provided in this embodiment:

[0083] The tool status during the placement process is as follows: Figure 1 As shown, at this time, the clamping spring cooperates with the center rod 11 to lock, and the two elastic claws 18 are locked together by the locking steel wire 19. When the delivery pipe string of the launcher is lowered to 5-8 meters below the designed oil pipe coupling position, the lowering of the pipe string is stopped.

[0084] Reference Figures 12 to 18 Slowly raise the delivery pipe string using the placement device. When the placement device passes the designed oil pipe coupling position, the locking wire 19 will spring away from the oil pipe coupling, and the elastic claw 18 will return to its free state (as shown). Figure 12 As shown in the diagram, the elastic claw 18 will anchor into the tubing coupling seam. Continuing to lift the deployed tubing string, the weight suspended on the well test vehicle will fluctuate significantly. At this point, the tubing string is slowly lowered. First, the elastic claw 18 will anchor into the tubing coupling seam. Because the protrusion below the elastic claw 18 is designed as a right-angled step 181, it forms a stable limit after anchoring into the tubing coupling seam, preventing further descent. At this point, the entire weight of the deployed tubing string is transferred to the center rod 11. Under the pressure from above, the groove of the center rod 11 will separate from the retaining spring 16, and the center rod 11 will move downwards until the lower step block 113 of the center rod 11 fully contacts the elastic claw 18, forming a limit. During the entire operation of the central rod 11, the cup 14 first moves along the conical surface of the cone 13, forming a seal with the oil pipe. Then, the rubber sleeve 12 forms a seal with the inner wall of the oil pipe under pressure. After the rubber sleeve 12, cup 14, and oil pipe form a seal, the central rod 11 is precisely limited by the elastic claw 18, and the central rod 11 stops descending. Under the pressure of the delivery pipe string, the cone 5 continues to descend, forming relative movement with the slip 6. The slip 6 expands outward along the conical slide 52 of the cone 5 until it engages with the inner wall of the oil pipe. At this point, the anchoring and sealing of the anchor are completed. This forms a double anchoring of the slip 6 and elastic claw 18 with the inner wall of the oil pipe and the oil pipe coupling seam, respectively, and a double seal of the rubber sleeve 12, cup 14, and inner wall of the oil pipe.

[0085] Using a shocker to knock down the delivery pipe string, the delivery bucket pin is cut short, causing it to separate from the setter. Slowly lift the delivery pipe string; if there is no significant change in the suspended weight, it proves that the delivery bucket has separated from the setter. Remove the delivery pipe string; the setter is now set.

[0086] III. The retrieval and unsealing process of the multi-stage plunger downhole deployment device provided in this embodiment.

[0087] The retrieval string for the landing device includes: steel wire, rope cap, weight rod, shock absorber, and retrieval cylinder.

[0088] The retrieval string, consisting of a steel wire, rope cap, weight rod, shock absorber, and retrieval barrel, is connected and lowered into the wellbore. When the retrieval string is lowered to the top of the setter, the retrieval barrel connects to the retrieval head 1 on the setter. The retrieval string is then lifted. Under the lifting force, the conical body 5 moves relative to the slips 6. The slips 6, under the action of the elastic outer clamp 7, contract along the conical slide 52 of the conical body 5 and disengage from the inner wall of the tubing. The retrieval string continues to be lifted until the conical body 5... After the limiting block moves along the slide of the drain section 9 to the uppermost end, it will continue to drive the drain section 9 and the center rod 11 to move upward. As the center rod 11 moves upward, the rubber sleeve 12 and the cup 14 will retract and unseal under the action of elastic force. When the center rod 11 continues to move upward, the lower step block 113 contacts the outer ring 17. At this time, the center rod 11 will drive the elastic claw 18 to move upward. Under the action of upward lifting force, the elastic claw 18 will retract and be pulled out from the oil pipe coupling seam. The seat is completely released from the oil pipe.

[0089] Continue lifting the retrieval string to retrieve the landing device out of the wellbore.

[0090] The multi-stage plunger downhole device provided in this embodiment can facilitate the deployment and retrieval of the multi-stage device, withstand the bidirectional impact of the upper and lower plungers during operation, and prevent the liquid at the top of the device from falling back.

[0091] The multi-stage plunger downhole placement device provided in this embodiment is not limited by the descent speed during deployment and is easy to deploy; the multi-stage plunger downhole placement device provided in this embodiment has low unsealing force and is easy to retrieve.

[0092] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A downhole placement device for a multi-stage plunger, characterized in that, include: Conical body (5), slip (6), slip connector (8), drain section (9), steel ball (10), center rod (11), rubber sleeve (12), cone (13), leather cup (14), inner washer (15), outer ring (17), elastic claw (18) and locking wire (19); The slip (6), the slip connector (8), the drain section (9), and the center rod (11) are connected in sequence; The conical body (5) is inserted into the slip (6) and the slip connector (8) and extends into the drain section (9). The conical body (5) is slidably connected to the drain section (9). A conical slide (52) is provided at the end of the conical body (5) away from the drain section (9). The slip (6) can move along the conical slide (52). One end of the central rod (11) is inserted into the drainage section (9), and the steel ball (10) abuts against the port of the central rod (11) near the drainage section (9) so that the liquid in the flow channel of the central rod (11) can run upward and cannot fall back from the central rod (11); The rubber sleeve (12), the cone (13), the cup (14), the inner washer (15), and the outer ring (17) are sequentially fitted onto the outside of the central rod (11) in a direction away from the draining section (9) and can slide relative to the central rod (11). The outer ring (17) is threadedly connected to the elastic claw (18). One end of the central rod (11) away from the steel ball (10) extends into the elastic claw (18) and can slide relative to the elastic claw (18). The elastic claw (18) is provided with a right-angle step (181) for engaging with the tubing coupling. The elastic claw (18) is locked by the locking wire (19) so that the right-angle step (181) is not engaged with the tubing coupling. When the locking wire (19) contacts the tubing coupling and springs open, the locking wire (19) releases the locking of the elastic claw (18), and the right-angle step (181) extends into the tubing coupling and engages with the tubing coupling, thus forming the first anchor. When the center rod (11) moves toward the locking wire (19), the cup (14) can move along the conical surface of the cone (13) to abut against the inner wall of the oil pipe, thus forming the first seal. When the center rod (11) moves toward the locking wire (19), the end of the drain section (9) away from the slip connector (8) can abut against the rubber sleeve (12), and the rubber sleeve (12) abuts against the inner wall of the oil pipe under pressure, thus forming a second seal. When the slip (6) expands along the conical slide (52) in a direction away from the axis of the slip (6) until the slip (6) engages with the inner wall of the oil pipe, a second anchor is formed.

2. The downhole placement device for multi-stage plungers according to claim 1, characterized in that, It also includes an upper retrieval head (1), an upper support rod (2), an upper shock-absorbing spring (3), and an upper support base (4); The upper retrieval head (1) is threadedly connected to the upper support rod (2), and the upper support rod (2) extends into the upper support seat (4) and can move relative to the upper support seat (4); The upper shock-absorbing spring (3) is sleeved on the outside of the upper support rod (2). One end of the upper shock-absorbing spring (3) is connected to the upper retrieval head (1), and the other end is connected to the upper support seat (4). The upper support (4) is connected to the cone (5).

3. The downhole placement device for multi-stage plungers according to claim 2, characterized in that, It also includes a lower support base (20), a lower shock-absorbing spring (21), a lower support rod (22), and a lower retrieval head (23); The lower retrieval head (23) is threadedly connected to the lower support rod (22), and the lower support rod (22) extends into the lower support seat (20) and is movable relative to the lower support seat (20); The lower shock absorber spring (21) is sleeved on the outside of the lower support rod (22). One end of the lower shock absorber spring (21) is connected to the lower retrieval head (23), and the other end is connected to the lower support seat (20). The lower end of the elastic claw (18) is connected to the lower support seat (20) by a thread.

4. The downhole placement device for multi-stage plungers according to claim 3, characterized in that, The slip connector (8) has a through hole (81), and the slip (6) is connected to the slip connector (8) through the through hole (81).

5. The downhole placement device for multi-stage plungers according to claim 4, characterized in that, The cone (5) is provided with an upper limit block (51), and the drain section (9) is provided with a groove (91), and the limit block is slidably connected to the groove (91).

6. The downhole placement device for multi-stage plungers according to claim 1, characterized in that, It also includes elastic external clamps (7); The elastic outer clamp (7) is fitted onto the outside of the clamp (6).

7. The downhole placement device for multi-stage plungers according to claim 6, characterized in that, The drainage section (9) is provided with a drainage hole (92) for drainage.

8. The downhole placement device for multi-stage plungers according to claim 7, characterized in that, It also includes snap rings (16); The inner washer (15) is threaded to the outer ring (17) and forms a groove (171), with the outer ring of the retaining spring (16) extending into the groove (171).

9. The downhole placement device for multi-stage plungers according to claim 8, characterized in that, The center rod (11) is provided with an upper groove (111) and a lower groove (112) for engaging with the inner ring of the snap ring (16).

10. The downhole placement device for multi-stage plungers according to claim 1, characterized in that, The central rod (11) is provided with a lower step block (113), and the elastic claw (18) is provided with a chamfer (182) for abutting against the lower step block (113).

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