Release anchor

Abstract

The releasing anchor, the upper connector and the upper end of the connecting rod are detachably connected through a releasing shear pin, the outer wall of the middle section of the connecting rod is sleeved with a limiting claw, the outer wall of the upper end of the limiting claw is connected with the inner wall of the lower end of the upper connector, the lower end of the connecting rod is inserted into an inner hole of the mandrel, and an outwards-protruding step at the lower end of the connecting rod expands the lower end of the limiting claw in the radial direction. And the outer convex part at the lower end part of the limiting claw is limited by the inner convex step at the upper end of the mandrel. The releasing mechanism is connected with and separated from the upper end of the core shaft through opening and retracting of the limiting claw, so that the releasing mechanism can be separated from a lower structure to be independently lifted, taken out and recycled. And after being taken out, the releasing anchor can still stably hang an oil pipe and a tool at the lower end.

Description

Technical Field

[0001] This utility model relates to oil and gas development well completion tools, specifically a hand-release anchor. Background Technology

[0002] During intelligent well completion operations in oil and gas, it is necessary to understand the downhole working environment and conditions. Currently, there are two common methods for downhole information transmission: hydraulic control lines and cable-based methods. Due to their structural design, the tools used in these two methods are generally long; and most of these tools cannot be retrieved separately from the upper section of the tubing after they are run down with the tubing.

[0003] To solve this technical problem, a release anchor needs to be designed that can stably suspend the lower section of the oil pipe and tools after the upper section of the oil pipe is removed, and has a relatively short overall length. Summary of the Invention

[0004] This invention aims to solve the problem of the inability to remove the upper section of the oil pipe separately, and provides a hand-release anchor that is simple to operate, has stable performance, and allows for easy removal of the upper section of the oil pipe after anchoring.

[0005] To achieve the above objectives, the release mechanism in the technical solution adopted by this utility model includes an upper connector, a connecting rod, and a limiting claw. The inner wall of the middle section of the inner hole of the upper connector is detachably connected to the outer wall of the upper end of the connecting rod. The limiting claw is fitted on the outer wall of the middle section of the connecting rod. The outer wall of the upper end of the limiting claw is connected to the inner wall of the lower end of the upper connector. The lower end of the connecting rod is inserted into the inner hole of the mandrel. The protruding step on the outer wall of the lower end of the connecting rod radially expands the lower end of the limiting claw, so that the protruding part on the outer wall of the lower end of the limiting claw is limited by the protruding step on the inner wall of the upper end of the mandrel, thus preventing it from moving upward.

[0006] This also includes a ball. When releasing the ball after the sealing is completed, it is placed into the upper end of the inner hole of the connecting pipe to form a seal and prevent hydraulic leakage during pressurization.

[0007] The upper outer wall of the mandrel is connected to the inner wall of the salvage neck. The shape of the salvage neck matches the salvage claw of the salvage tool. The outer wall of the salvage neck can be detachably connected to the inner wall of the upper cylinder. The lower end of the upper cylinder is connected to the upper end of the upper cone of the anchoring mechanism.

[0008] The outer wall of the salvage neck is provided with an upward protruding step, and the upper end of the inner hole of the outer cylinder is provided with a corresponding upward protruding step. When the salvage neck separates from the upper cylinder and moves upward, the upward protruding step contacts the upward protruding step and drives the outer cylinder to move upward together.

[0009] It also includes a split ring. The upper outer wall of the mandrel has an outwardly protruding limiting step. The upper and lower ends of the split ring abut against the lower end face of the limiting step and the upper end face of the upper cone, respectively. The outer wall of the split ring is radially limited by the inner wall of the retrieval neck. After the retrieval neck separates from the upper cylinder and moves upward, the split ring expands outward and disengages from the limiting step, thus no longer limiting the upper cone, allowing it to move upward together with the upper cylinder.

[0010] The anchoring mechanism includes an upper cone, an outer tube, a slip, and a lower cone. The axially movable outer tube is sleeved on the mandrel. The upper cone, slip, and lower cone are sequentially arranged on the outer wall of the outer tube. The lower end of the outer tube is also connected to the inner wall of the lower cone. When the outer tube moves upward, it drives the lower cone to move upward. The upper cone and the lower cone squeeze each other through their inclined surfaces and push the slip to expand radially to complete the anchoring.

[0011] Among them, the kawa is a two-way kawa.

[0012] The setting mechanism includes a locking sleeve, a locking ring, a piston, and a hydraulic cylinder. The upper end of the locking sleeve is detachably connected to the lower end of the lower cone, and the lower end of the locking sleeve is connected to the upper end of the hydraulic cylinder. The lower end of the hydraulic cylinder is connected to the outer wall of the mandrel. An axially movable piston is provided between the inner wall of the hydraulic cylinder and the outer wall of the mandrel. The upper end of the piston presses against the lower end of the outer tube, and the pressure transmission hole on the side wall of the mandrel connects the interior of the mandrel with the lower end of the piston.

[0013] The lock sleeve is also equipped with a locking ring inside, and a backstop mechanism is provided between the inner wall of the locking teeth and the outer wall of the piston;

[0014] During setting, the lower end of the mandrel is plugged, and the pressure is transmitted through the pressure hole to push the piston upward. The piston pushes the mandrel upward, which in turn drives the lower cone upward.

[0015] Among them, an anti-rotation screw is provided between the lower end of the upper connector and the limiting claw; an anti-rotation screw is provided between the outer wall of the upper cylinder and the upper cone; and an anti-rotation screw is provided between the locking sleeve and the locking ring.

[0016] The inner wall of the central hole of the upper connector is detachably connected to the outer wall of the upper end of the connecting rod via a release scissor pin. The outer wall of the retrieval neck is detachably connected to the inner wall of the upper cylinder via a release scissor pin.

[0017] The upper end of the locking sleeve is detachably connected to the lower end of the lower cone via a seated shear pin.

[0018] A sealing assembly is provided between the inner wall of the central hole of the upper connector and the outer wall of the upper end of the connecting rod.

[0019] A sealing assembly is provided between the lower outer wall of the connecting rod and the inner wall of the mandrel's inner hole.

[0020] Sealing assemblies are provided between the inner wall of the piston and the outer wall of the spindle, and between the outer wall of the piston and the inner wall of the hydraulic cylinder.

[0021] Compared with the existing technology, this utility model completes the connection and disconnection with the upper end of the mandrel by opening and retracting the limiting claw, so that the release mechanism can be lifted up independently from the lower structure and taken out / retrieved with the upper oil pipe, thus separating into upper and lower oil pipe sections; after being taken out, the release anchor can still stably suspend the lower oil pipe and tools, and can support the signal transmitter and receiver to communicate and transmit downhole parameter information. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the structure of an embodiment of the present utility model;

[0023] See attached diagram: upper connector (1), O-ring (2), retaining ring (3), release shear pin (4), connecting rod (5), limiting claw (6), anti-rotation screw (7), retrieval neck (8), upper cylinder (9), release shear pin (10), split ring (11), set screw (12), upper cone (13), mandrel (14), outer tube (15), slip (16), lower cone (17), setting shear pin (18), locking sleeve (19), locking ring (20), piston (21), hydraulic cylinder (22), ball (27). Detailed Implementation

[0024] The present invention will now be further described with reference to the accompanying drawings. See also: Figure 1 , Figure 1 This illustration shows an embodiment of the present invention: a release anchor, which mainly consists of a release mechanism, an anchoring mechanism, and a setting mechanism. For ease of description, the direction of the upper connector will be referred to as "upper" in the following text, and vice versa.

[0025] The release mechanism includes an upper connector, a connecting rod, and a limiting pawl. Both the upper connector and the connecting rod are tubular structures with axially extending holes at both ends. The upper part of the limiting pawl is tubular, while its lower part consists of several segmented pawl structures, with the pawl ends capable of radial extension and retraction. The inner wall of the middle section of the hole in the upper connector is detachably connected to the outer wall of the upper end of the connecting rod via a release scissor pin. The limiting pawl is fitted onto the outer wall of the middle section of the connecting rod, and its upper outer wall is threaded to the inner wall of the lower end of the upper connector. The lower end of the connecting rod is inserted into the inner hole of the mandrel. An outwardly protruding step on the outer wall of the lower end of the connecting rod contacts the inner wall of the lower end of the limiting pawl. The inner wall of the upper end of the mandrel has a correspondingly matching inwardly protruding step, and the outer wall of the lower end of the limiting pawl also has an outwardly protruding portion. Initially, the lower end of the limiting pawl extends into the inner hole of the mandrel, with the outwardly protruding portion located below the inwardly protruding step. The outward protruding step of the connecting rod pushes the lower end of the limiting claw outward in a radial direction, so that the outward protrusion on the outer wall of the lower end of the limiting claw is axially limited by the inner protruding step on the inner wall of the upper end of the mandrel, thereby preventing the limiting claw from separating from the mandrel and moving upward.

[0026] Preferably, sealing components are provided between the inner wall of the central hole of the upper connector and the outer wall of the upper end of the connecting rod, and between the outer wall of the lower end of the connecting rod and the inner wall of the inner hole of the mandrel. O-ring-stop ring structure and O-ring are respectively set in the corresponding sealing groove to form a sealing structure.

[0027] Preferably, an anti-rotation screw is provided between the lower end of the upper connector and the limiting claw.

[0028] It also includes a ball. When releasing the ball after the sealing is completed, the ball is dropped into the upper end of the inner hole of the connecting pipe. The ball surface and the upper end face of the inner hole of the connecting rod form a sealing surface to prevent hydraulic leakage during pressurization.

[0029] It also includes components for retrieval. The upper outer wall of the mandrel is connected to the inner wall of the retrieval neck, and the outer wall of the retrieval neck is fitted with an upper cylinder. The shape of the upper end of the retrieval neck matches the retrieval claw of the retrieval tool. After the release mechanism releases the retrieval neck, the matching retrieval tool is lowered in, and the retrieval tool can grab the retrieval neck. The outer wall of the retrieval neck is detachably connected to the inner wall of the upper cylinder through a release shear pin. The lower end of the upper cylinder is connected to the upper end of the upper cone of the anchoring mechanism.

[0030] Furthermore, the outer wall of the salvage neck is provided with an upward-facing outward protruding step, and the upper end of the inner hole of the outer cylinder is provided with a corresponding upward-facing inward protruding step. When the salvage neck separates from the upper cylinder and moves upward, the upper end face of the upward-facing outward protruding step can contact the lower end face of the upward-facing inward protruding step, and drive the outer cylinder and the upper cone connected to the lower end of the outer cylinder to move upward together.

[0031] Furthermore, it also includes a split ring. The upper outer wall of the mandrel has a protruding limiting step, and the lower inner wall of the retrieval neck has a corresponding notched ring. The split ring is located between the lower end face of the limiting step and the inner wall of the retrieval neck, and its outer wall is radially limited by the inner wall of the retrieval neck. The upper and lower ends of the split ring abut against the lower end face of the limiting step and the upper end face of the upper cone, respectively, limiting the upward movement of the lower cone.

[0032] After the salvage neck separates from the upper cylinder, it moves upward. The inner wall of the salvage neck disengages from the outer wall of the split ring, and the split ring expands radially outward. Furthermore, its inner wall and upper end disengage from the outer wall of the mandrel and the lower end face of the limiting step, respectively. As a result, it no longer limits the upper end of the upper cone, allowing it to move upward together with the upper cylinder.

[0033] Furthermore, the anchoring mechanism in this embodiment includes an upper cone, an outer tube, a slip, and a lower cone; wherein the outer tube, which can move axially up and down, is sleeved on the mandrel, and the upper cone, slip, and lower cone are sequentially sleeved on the outer wall of the outer tube from top to bottom, and the lower end of the outer tube is also connected to the inner wall of the lower cone.

[0034] When the outer tube is pushed upward by the piston and moves upward along with the lower cone, the upper and lower cones contact the slips, and the slips are squeezed by the upper and lower inclined surfaces respectively, pushing the slips to expand radially and engage with the inner wall of the sleeve to complete the setting seal.

[0035] As a preferred option, the slips are bidirectional slips. The use of bidirectional slips allows the release anchor to withstand axial loads in both the upper and lower directions. Pressurization within the oil pipe is sufficient to set the slips, and the setting position can be freely selected.

[0036] Preferably, a set screw or anti-rotation screw is provided between the lower end of the upper cylinder and the outer wall of the upper cone. Further, the setting mechanism in this embodiment includes a locking sleeve, a locking ring, a piston, and a hydraulic cylinder. The upper end of the locking sleeve is detachably connected to the lower end of the lower cone via a setting shear pin; the lower end of the locking sleeve is threadedly connected to the upper end of the hydraulic cylinder; and the lower end of the hydraulic cylinder is connected to the outer wall of the mandrel.

[0037] A piston that can move axially is provided between the inner wall of the hydraulic cylinder and the outer wall of the mandrel. The upper end of the piston presses against the lower end of the outer tube. The upper outer wall of the piston is connected to the inner wall of the lower cone by a thread. The pressure transmission hole on the side wall of the mandrel connects the interior of the mandrel with the lower end of the piston.

[0038] The locking ring is installed inside the locking sleeve, and its locking teeth form a backstop mechanism with the outer wall of the piston, preventing the piston from retracting after moving upwards. Preferably, an anti-rotation screw is provided between the locking sleeve and the locking ring.

[0039] Preferably, sealing components (an O-ring-retaining ring-O-ring structure is provided between the inner wall of the piston and the outer wall of the mandrel, and between the outer wall of the piston and the inner wall of the hydraulic cylinder) are provided to form a sealing structure. During setting, the lower end of the mandrel is plugged, and the pressure pushes the piston upward through the pressure transmission hole. The piston pushes the mandrel upward, causing the lower cone to move upward together.

[0040] The usage process of this embodiment is as follows:

[0041] Setting: The embodiment is lowered to the designated position, and then the lower end of the release anchor is plugged. The resulting pressure enters the internal cavity formed between the inner wall of the hydraulic cylinder, the lower end face of the piston, and the outer wall of the mandrel through the pressure transmission hole of the mandrel. The pressure is transmitted to the lower end face of the piston, pushing the piston upward axially, and then pushing the outer tube upward. At the same time, the piston also drives the lower cone upward and shears the setting shear pin. During the upward movement, the lower cone moves towards the stationary upper cone and cooperates with it, jointly pushing the slips radially outward through their respective inclined surfaces until their outer walls engage with the inner wall of the sleeve, thus completing the slip anchoring / setting.

[0042] Then, increase the pressure to the pressure value required to dislodge the ball seat below, cut the ball seat pin (not shown in the figure), and the internal pressure of the spindle will automatically release.

[0043] Release: Insert a ball into the upper connector that matches the sealing surface size of the upper end face of the connecting rod's central hole. After the ball and connecting rod are sealed, apply pressure. The connecting rod is then pressed downwards, shearing the release shear pin and moving downwards. When the outer convex step moves downwards to the position where it completely disengages from the inner wall of the lower end of the limiting pawl, the lower end of the radially expanded limiting pawl retracts radially inwards to the smaller diameter section of the outer wall in the middle of the connecting rod. Consequently, its outer convex part no longer overlaps with the inner convex step of the mandrel in the axial direction. That is, the limiting pawl is released from its upward movement restriction and can pass upwards through the upper opening of the mandrel's inner hole.

[0044] The tubing string is then lifted, and the upper connector and limiting claw, connected by threads, follow the tubing string upwards, separating the release mechanism from the other structures below. After following the tubing string upwards, the retrieval is completed. After the release is completed, the lower section of the release anchor can still stably suspend the lower tubing and tools.

[0045] Salvage: Lower the salvage tool compatible with the release anchor. Slowly press down the tubing near the release anchor. Once the salvage claws are engaged in the salvage neck, lift the tubing. Continue applying upward force until the release pins are sheared off, separating the salvage neck from the outer cylinder and allowing it to move upward with the salvage claws.

[0046] At this point, the salvage neck disengages from the split ring, releasing the split ring's axial freedom and causing the upper cone to lose its downward force. Simultaneously, the upward-protruding step on the outer wall of the salvage neck contacts the upward-protruding step on the inner wall of the upper cylinder's inner bore, causing the upper cylinder to move upward. The upper cylinder then pulls the upper cone, which is threadedly connected to it, upward. With the lower cone stationary, the upward movement of the upper cone removes the force exerted by the inclined surfaces on both ends of the slips, causing the slips to retract radially and disengage from the inner wall of the casing. The release anchor then disengages, completing the salvage operation.

[0047] In this embodiment, the release mechanism can be removed along with the upper oil pipe after release, while the release anchor can still stably suspend the lower oil pipe and tools. Furthermore, its relatively short overall length does not affect communication and information transmission between the re-entered tubing and tools and the tools suspended at the lower end of the release anchor.

[0048] The embodiments of this utility model have been described above with reference to the accompanying drawings and examples. The structures given in the embodiments do not constitute a limitation on this utility model. Those skilled in the art can make adjustments as needed, and various modifications or variations within the scope of the appended claims are all within the scope of protection.

Claims

1. A release anchor, characterized in that: The release mechanism includes an upper connector, a connecting rod, and a limiting pawl. The inner wall of the central hole of the upper connector is separably connected to the outer wall of the upper end of the connecting rod. The limiting pawl is fitted on the outer wall of the middle section of the connecting rod. The outer wall of the upper end of the limiting pawl is connected to the inner wall of the lower end of the upper connector. The lower end of the connecting rod is inserted into the inner hole of the mandrel. The protruding step on the outer wall of the lower end of the connecting rod radially expands the limiting pawl, so that the protruding part on the outer wall of the limiting pawl is limited by the protruding step on the inner wall of the upper end of the mandrel.

2. The release anchor as described in claim 1, characterized in that: It also includes a ball. When releasing the ball after the sealing is completed, the ball is dropped into the upper end of the inner hole of the connecting pipe to form a seal.

3. The release anchor as described in claim 1, characterized in that: The upper outer wall of the mandrel is connected to the inner wall of the retrieval neck. The outer wall of the retrieval neck can be detachably connected to the inner wall of the upper cylinder. The lower end of the upper cylinder is connected to the upper cone of the anchoring mechanism. The outer wall of the salvage neck is also provided with an upward protruding step, and the upper end of the inner hole of the outer cylinder is provided with a corresponding upward protruding step; when the salvage neck separates from the upper cylinder and moves upward, the upward protruding step contacts the upward protruding step and drives the outer cylinder to move upward together.

4. The release anchor according to claim 3, characterized in that: It also includes a split ring, and the upper outer wall of the mandrel is provided with an outwardly protruding limiting step. The upper and lower ends of the split ring abut against the lower end face of the limiting step and the upper end face of the upper cone, respectively. The outer wall of the split ring is radially limited by the inner wall of the retrieval neck. After the salvage neck separates from the upper cylinder, it moves upward. The split ring expands outward and disengages from the limiting step, thus no longer limiting the upper cone, allowing it to move upward together with the upper cylinder.

5. The release anchor according to claim 3, characterized in that: The anchoring mechanism includes an upper cone, an outer tube, a slip, and a lower cone. The axially movable outer tube is sleeved on the mandrel. The upper cone, slip, and lower cone are sequentially arranged on the outer wall of the outer tube. The lower end of the outer tube is also connected to the inner wall of the lower cone. When the outer tube moves upward, it drives the lower cone to move upward. The upper cone and the lower cone squeeze each other through their inclined surfaces and push the slip to expand radially to complete the anchoring.

6. The release anchor according to claim 5, characterized in that: The slip is a two-way slip.

7. The release anchor as claimed in claim 1, characterized in that: The setting mechanism includes a locking sleeve, a locking ring, a piston, and a hydraulic cylinder. The upper end of the locking sleeve is detachably connected to the lower end of the lower cone, the lower end of the locking sleeve is connected to the upper end of the hydraulic cylinder, and the lower end of the hydraulic cylinder is connected to the outer wall of the mandrel. A piston that can move axially is provided between the inner wall of the hydraulic cylinder and the outer wall of the mandrel. The upper end of the piston is connected to the lower cone, and the upper end of the piston presses against the lower end of the outer tube. The pressure transmission hole on the side wall of the mandrel connects the interior of the mandrel with the lower end of the piston. The lock sleeve is also equipped with a locking ring inside, and a backstop mechanism is provided between the inner wall of the locking teeth and the outer wall of the piston; During setting, the lower end of the mandrel is plugged, and the pressure pushes the piston upward through the pressure transmission hole. The piston pushes the lower cone upward together.

8. The release anchor according to any one of claims 1-7, characterized in that: An anti-rotation screw is provided between the lower end of the upper connector and the limiting claw; and / or an anti-rotation screw is provided between the outer wall of the upper cylinder and the upper cone; and / or an anti-rotation screw is provided between the locking sleeve and the locking ring.

9. The release anchor according to any one of claims 1-7, characterized in that: The inner wall of the central hole of the upper connector is detachably connected to the outer wall of the upper end of the connecting rod by a release shear pin; and / or the outer wall of the retrieval neck is detachably connected to the inner wall of the upper cylinder by a release shear pin; and / or the upper end of the locking sleeve is detachably connected to the lower end of the lower cone by a setting shear pin.

10. The release anchor according to any one of claims 1-7, characterized in that: A sealing assembly is provided between the inner wall of the central hole of the upper connector and the outer wall of the upper end of the connecting rod; and / or a sealing assembly is provided between the outer wall of the lower end of the connecting rod and the inner wall of the inner hole of the mandrel; and / or sealing assemblies are provided between the inner wall of the piston and the outer wall of the mandrel, and between the outer wall of the piston and the inner wall of the hydraulic cylinder.

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