Annular pressure deblocking packer capable of being repeatedly set

Abstract

According to the annular pressure deblocking packer capable of being repeatedly set, the lower end of an outer pipe is connected with a lower rubber cylinder seat, a sectioning groove is formed in the upper end of the outer pipe, and a sectioning claw is arranged at the lower end of a deblocking piston and embedded into the sectioning groove; the lock sleeve is arranged between the upper joint and the upper rubber sleeve seat, and lock sleeve lock teeth are arranged on the inner wall of the lock sleeve; the elastic lock ring is arranged in the lock sleeve and arranged on the middle section of the sectioning claw of the deblocking piston in a sleeving mode, and lock teeth on the outer wall of the elastic lock ring are connected with lock teeth of the lock sleeve. Inner wall locking teeth are arranged on the inner wall of the elastic locking ring; when the outer pipe moves upwards, the outer pipe is locked with the inner wall locking teeth; a slope guide groove is formed in the inner wall of the elastic locking ring, the deblocking piston sectioning claw is provided with a corresponding reducing structure, and when the deblocking piston moves upwards, the reducing structure radially opens the elastic locking ring so that the elastic locking ring can be disengaged from the outer pipe. Through mutual cooperation of expansion and retraction of the elastic locking ring with the variable diameter and hydraulic pushing, repeated setting and unsetting operation can be achieved under the condition that a pipe column is not lifted, stratum damage is reduced, the accident occurrence probability is reduced, and the working efficiency is improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to an oil and gas field completion tool, in particular to an annular pressure unblocking packer with repeated setting. BACKGROUND

[0002] The packer is used for sealing the annular space between various size pipe columns and wellbores or between pipe columns to achieve the purpose of isolating production layers and protecting casings; its performance is crucial to oil exploitation. With the increase of complex reservoir structure and multi-layer exploitation demand, packers with repeated setting are needed.

[0003] The existing packer has limited unblocking mode: the pipe column needs to be lifted, and such unblocking operation may be limited in complex downhole environment and is difficult to repeat setting; or the packer structure is easily damaged after repeated setting, resulting in damaged sealing performance and further affecting the effect of repeated setting. In particular, there is a contradiction between the sealing performance and repeated setting, and part of the sealing element is easily worn and deformed in the operation of repeatedly lifting the pipe column, which may cause sealing failure. SUMMARY

[0004] The utility model discloses to solve the existing problem, aims at providing a kind of annular pressure unblocking packer with repeated setting.

[0005] In order to achieve the above purpose, the utility model discloses the technical scheme that is equipped with upper joint, upper rubber cylinder seat, rubber cylinder assembly, lower rubber cylinder seat, lower joint from top to bottom in sequence, and the center tube fixedly arranged in the inside, characterized by: further comprising outer tube, lock sleeve, elastic lock ring and unblocking piston, wherein:

[0006] The outer tube and the unblocking piston can move up and down and are sleeved on the outer wall of the center tube, the lower end of the outer tube is connected with the lower rubber cylinder seat, and the upper end of the outer tube is provided with a plurality of split slots;The lower end of the unblocking piston is provided with a plurality of split claws, and the split claws are embedded in the split slots of the outer tube correspondingly;

[0007] The lock sleeve is arranged between the upper joint and the upper rubber cylinder seat, and the inner wall of the lock sleeve is provided with lock teeth;The elastic lock ring is arranged in the lock sleeve and is sleeved on the middle section of the split claw of the unblocking piston, and the outer wall lock teeth of the elastic lock ring are connected with the lock teeth of the lock sleeve in position;The inner wall of the elastic lock ring is provided with inner wall lock teeth, and when setting, the upper end outer wall of the outer tube can be locked with the corresponding setting lock teeth;

[0008] The inner wall of the elastic lock ring is further provided with a plurality of inclined surface guide grooves, and the lower section outer wall of the split claw of the unblocking piston is provided with a corresponding variable diameter structure expanding from top to bottom, and when unblocking, the unblocking piston goes up, the variable diameter structure radially expands the elastic lock ring, so that it is loose with the outer tube.

[0009] The lower end of the liquid cylinder is connected with the lower joint, and the hydraulic cylinder II formed between the inner wall of the liquid cylinder and the outer wall of the central pipe is provided with an upper piston which can move up and down, the upper piston is connected with the lower end of the lower rubber cylinder seat through a shear pin.

[0010] The side wall of the central pipe is further provided with a lower pressure transmission hole II which connects the lower end of the upper piston and transmits the hydraulic pressure upward, and the upper piston can move upward and push the lower rubber cylinder seat upward.

[0011] The inner wall of the upper part of the upper piston and the outer wall of the central pipe form a hydraulic cylinder I, and the side wall of the central pipe is provided with a lower pressure transmission hole I which connects the hydraulic cylinder I and transmits the hydraulic pressure to the lower end of the lower rubber cylinder seat to push it upward.

[0012] The lower joint and the central pipe form a hydraulic cylinder III in which a lower piston which can move up and down is arranged, the upper end of the lower piston abuts against the lower end of the upper piston, and the side wall of the central pipe is further provided with a lower pressure transmission hole III which connects the lower end of the lower piston and transmits the hydraulic pressure upward.

[0013] The side wall of the upper section of the central pipe is provided with an upper pressure transmission hole which connects the upper end of the unsealing piston and transmits the hydraulic pressure downward.

[0014] The side wall of the upper rubber cylinder seat is provided with an unsealing hole which connects the lower end of the unsealing piston.

[0015] The lock sleeve and the elastic lock ring are further limited by a screw.

[0016] The split claw, the split groove and the inclined surface guide groove are evenly distributed along the circumference.

[0017] The number of the split claw, the split groove and the inclined surface guide groove is four.

[0018] The inner wall and the outer wall of the upper part of the unsealing piston and the outer wall of the central pipe and the inner wall of the upper joint are respectively provided with sealing rings.

[0019] The inner wall of the lower rubber cylinder seat and the outer wall of the outer pipe are provided with a sealing ring.

[0020] The inner wall and the outer wall of the lower part of the upper piston and the outer wall of the central pipe and the inner wall of the liquid cylinder, and the inner wall of the upper part of the upper piston and the outer wall of the central pipe are respectively provided with sealing rings.

[0021] The inner wall and the outer wall of the lower part of the lower piston and the outer wall of the central pipe and the inner wall of the lower joint, and the outer wall of the upper part of the lower piston and the inner wall of the liquid cylinder are respectively provided with sealing rings.

[0022] Compared with the prior art, the utility model discloses through the expansion, the shrinkage of the elastic lock ring of variable diameter and the mutual cooperation of hydraulic propelling, can realize repeatedly setting, unsetting operation without the pipe column, make the well flushing operation more flexible, improve the utilization efficiency of the well flushing fluid, reduce the formation damage, reduce the probability of the accident and the labor intensity of operation simultaneously, improve the work efficiency. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 It is the structure schematic diagram of the utility model embodiment;

[0024] Figure 2 It is the section view of the utility model embodiment;

[0025] Referring to the drawings, (1) upper joint, (2) central tube, (3) sealing ring, (4) variable diameter structure, (5) unsetting piston, (6) lock sleeve, (7) elastic lock ring, (8) screw, (9) upper rubber cylinder seat, (10) outer tube, (11) shoulder guard, (12) end rubber cylinder, (13) spacer ring, (14) middle rubber cylinder, (15) rubber cylinder inner ring, (16) lower rubber cylinder seat, (17) split claw, (18) split groove, (19) shear pin, (20) upper piston, (21) liquid cylinder, (22) lower central tube, (23) setting lock tooth, (24) lower piston, (25) lower joint. DETAILED DESCRIPTION

[0026] In order to better illustrate the use method of the device, the technical scheme in the utility model embodiment will be described completely in conjunction with the drawings in the utility model embodiment. For the convenience of description, the direction along the central axis to the upper joint is "up", and vice versa is "down".

[0027] Referring to Figure 1 , Figure 1 An embodiment of the utility model discloses a kind of annular space pressure unsetting packer that can repeatedly set, mainly including as outer sleeve component and being sequentially provided with upper joint, lock sleeve, upper rubber cylinder seat, rubber cylinder assembly, lower rubber cylinder seat, liquid cylinder and lower joint from top to bottom.

[0028] Wherein, rubber cylinder assembly sequentially includes upper shoulder, upper end rubber cylinder, upper spacer ring, middle rubber cylinder, lower spacer ring, lower end rubber cylinder, lower shoulder from top to bottom;Middle rubber cylinder inner wall and outer tube outer wall are also provided with rubber cylinder inner ring between them.The rubber cylinder assembly is prior art, after being extruded by the lower rubber cylinder seat upper end of its lower side uplink, can radially expand and complete setting.

[0029] And, a center tube fixedly arranged inside the outer sleeve; for the convenience of manufacture and installation, the lower section of the center tube is designed as a lower center tube in split body, and is connected through screw thread. The outer wall of the upper section of the center tube and the outer wall of the lower section of the lower center tube are respectively connected through screw thread with the inner wall of the upper joint and the lower joint. The outer wall of the upper section of the lower center tube is provided with a radially expanded convex structure for contacting and sealing with the inner wall of the upper end of the upper piston and forming the hydraulic cylinders I and II. And, the outer tube and the unsealing piston which can move up and down. See Figure 2 The outer tube and the unsealing piston are arranged inside the outer sleeve assembly and are respectively sleeved on the outer wall of the center tube, and the unsealing piston is located above the outer tube. The inner wall and the outer wall of the upper part of the unsealing piston are respectively provided with a sealing ring (O-ring) between the outer wall of the center tube and the inner wall of the upper joint, forming a sealing structure.

[0030] The lower end of the outer tube is connected with the lower rubber cylinder seat, and the outer wall of the upper end of the outer tube is provided with four split slot grooves which are uniformly distributed along the circumference. Correspondingly, the outer wall of the lower end of the unsealing piston is provided with four split pawl claws which are respectively embedded in the split slot grooves of the outer tube, forming a structure which can be meshed and limited with each other.

[0031] The upper and lower ends of the lock sleeve are respectively connected with the upper joint and the upper rubber cylinder seat, and the inner wall of the lock sleeve is provided with lock sleeve lock teeth. The elastic lock ring is arranged in the lock sleeve and is sleeved on the middle section of the split pawl claw of the unsealing piston, and the outer wall lock teeth of the elastic lock ring are limitedly connected with the lock sleeve lock teeth. The side wall of the upper rubber cylinder seat is provided with an unsealing through hole which is connected with the lower end of the unsealing piston.

[0032] As a preferred, a screw is further arranged between the lock sleeve and the elastic lock ring, and the end of the screw is inserted into the elastic lock ring from the outer wall of the elastic lock ring, further limiting the elastic lock ring.

[0033] Further, the inner wall of the elastic lock ring is provided with inner wall lock teeth (the inner wall part except the inclined surface guide groove); correspondingly, the outer wall of the upper end of the outer tube is provided with setting lock teeth. By setting the distribution position of the setting lock teeth, the setting lock teeth are not in contact with the inner wall lock teeth in the initial state. When the outer tube moves up in the setting operation, the setting lock teeth of the outer tube move up together and are in contact with the inner wall lock teeth and are locked.

[0034] Further, the inner wall of the elastic lock ring is further provided with four inclined surface guide grooves corresponding to the split pawl claws of the unsealing piston, which are uniformly distributed along the circumference. Correspondingly, the outer wall of the lower section of the split pawl claw of the unsealing piston is provided with a variable diameter structure which expands in diameter from top to bottom. See Figure 2 The thickness of the lower end of the split pawl claw is greater than the thickness of the upper claw body, that is, the diameter of the outer wall of the lower end is greater than the diameter of the outer wall of the upper section, forming a tapered surface.

[0035] In the initial state, the variable-diameter structure is located below the elastic lock ring, and the part of the unsealing piston in contact with the elastic lock ring has no diameter expansion, so the elastic lock ring is not stretched from the initial state to the setting. When unsealing, the unsealing piston is raised by hydraulic pressure, and the variable-diameter structure is raised together. As the variable-diameter structure continuously enters the inside of the elastic lock ring, the contact part of the split claw and the outer wall of the elastic lock ring gradually thickens, and the elastic lock ring is gradually stretched radially outward, and the inner wall lock teeth and the setting lock teeth of the outer pipe are finally loosened and separated. Subsequently, the outer pipe is no longer limited and can rely on its own gravity to descend.

[0036] Further, referring to Figure 1 , the lower end of the liquid cylinder is connected to the upper end of the lower joint, and the inner wall of the liquid cylinder and the outer wall of the lower central pipe form a hydraulic cylinder II, and an upper piston movable up and down is arranged in the hydraulic cylinder II. The inner wall and the outer wall of the lower part of the upper piston, the outer wall of the central pipe, and the inner wall of the liquid cylinder are respectively provided with sealing rings (O-rings), and the outer convex structure of the upper end of the lower central pipe and the outer wall of the lower rubber cylinder seat form a sealing structure.

[0037] The upper piston is detachably connected to the liquid cylinder through a shear pin, and the upper end of the upper piston is connected to the lower end of the lower rubber cylinder seat. A group of lower pressure transmission holes II are further arranged on the side wall of the middle segment of the lower central pipe, and there are four holes uniformly distributed along the circumference. The lower pressure transmission holes II connect the lower end of the upper piston from the inside of the lower central pipe and conduct hydraulic pressure upward. After the upper piston is pressed and the shear pin is cut off, the upper piston can ascend and push the lower rubber cylinder seat to ascend.

[0038] Referring to Figure 1 , the inner wall of the upper part of the upper piston, the lower end of the lower rubber cylinder seat, and the outer wall of the central pipe form a hydraulic cylinder I, and a sealing ring (O-ring) is arranged between the inner wall of the lower rubber cylinder seat and the outer wall of the outer pipe to form a sealing structure. A group of lower pressure transmission holes I are arranged on the side wall of the lower end of the central pipe, and there are four holes uniformly distributed along the circumference. The lower pressure transmission holes I connect the hydraulic cylinder I from the inside of the central pipe and conduct hydraulic pressure to the lower end of the lower rubber cylinder seat to push it to ascend. Referring to Figure 1 , the inner wall of the lower joint / liquid cylinder and the outer wall of the lower central pipe form a hydraulic cylinder III, and a lower piston movable up and down is arranged in the hydraulic cylinder III. The inner wall and the outer wall of the lower part of the lower piston, the outer wall of the lower central pipe, and the inner wall of the lower joint are respectively provided with sealing rings (O-rings), and the outer wall of the upper part of the lower piston and the inner wall of the liquid cylinder form a sealing structure. The upper end of the lower piston protrudes upward from the inner wall of the lower joint / liquid cylinder and the outer wall of the lower central pipe and abuts against the lower end of the upper piston; further, the upper end inner wall of the lower piston is provided with a cutout for the lower pressure transmission holes II to conduct hydraulic pressure to the lower end of the upper piston.

[0039] A group of lower pressure transmission holes III are further arranged on the side wall of the lower segment of the lower central pipe, and there are four holes uniformly distributed along the circumference. The lower pressure transmission holes III connect the lower end of the lower piston from the inside of the lower central pipe and conduct hydraulic pressure upward to push it to ascend.

[0040] When setting, the whole tool is lowered into the well, and hydraulic pressure is applied to the inside of the central tube and the lower central tube from the wellhead, and the hydraulic pressure is conducted along the lower three sets of pressure transmission holes I, pressure transmission holes II and pressure transmission holes III and acts on the lower end of the lower piston, the lower end of the upper piston and the lower end of the lower rubber sleeve seat, respectively, to push them upward. Under the action of the hydraulic pressure in the three hydraulic cylinders I, hydraulic cylinders II and hydraulic cylinders III, the upper piston moves upward under the push of the lower piston and shears the shear pin, and then simultaneously pushes the lower rubber sleeve seat upward, and the lower rubber sleeve seat pushes the outer tube upward. After the lower rubber sleeve seat moves upward, the upper end of the lower rubber sleeve seat extrudes the rubber sleeve, so that the rubber sleeve expands radially to form a sealing separation of the annular space. At the same time, the hydraulic pressure also pushes the unsetting piston along the upper transmission hole of the upper section of the central tube, so that the unsetting piston moves downward. The setting lock teeth on the outer wall of the outer tube after moving upward are also engaged with the inner wall lock teeth of the elastic lock ring, and are hung, and the setting lock teeth are arranged in a direction to form a locking / retaining structure, which can effectively prevent the unsetting from occurring in advance.

[0041] When unsetting, pressure is applied to the upper part of the annular space that is sealed, and the pressure enters the lower end of the unsetting piston through the unsetting hole in the sidewall of the upper rubber sleeve seat, so as to push the unsetting piston to move upward along the axial direction. During the movement of the unsetting piston, the variable-diameter structure of the split claw will interact with the inclined surface guide groove in the inner part of the elastic lock ring, so that the elastic lock ring is subjected to an outward radial expansion force, thereby being expanded and enlarged in size. As the elastic lock ring gradually expands, the limiting constraint effect of the elastic lock ring on the setting lock teeth on the upper end of the outer tube will gradually weaken and eventually disappear.

[0042] When the outer tube loses the limiting effect of the elastic lock ring, it will move downward along the axial direction under the action of its own gravity. With the downward movement of the outer tube, the lower rubber sleeve seat also moves downward, and the rubber sleeve that was extruded loses the extrusion force and also retracts radially, and the unsetting is completed.

[0043] Using annular pressure as the unsetting power source has advantages, and is more convenient in offshore platforms or cluster well exploitation operations where the wellhead space is limited, and is conducive to the design of a reusable setting packer to adapt to complex exploitation requirements.

[0044] The embodiments of the utility model are described above in combination with the drawings, and the structure given in the embodiments does not constitute a limitation on the utility model, and skilled persons in the art can make adjustments as needed, and various modifications or changes within the scope of the appended claims are within the protection scope.

Claims

1. A repeatable-set annulus pressure unsetting packer, comprising, from top to bottom, an upper joint, an upper rubber seat, a rubber seat assembly, a lower rubber seat, a lower joint, and a center tube fixedly arranged inside, characterized in that: It also includes an outer tube, a lock sleeve, an elastic lock ring and an unsealing piston, wherein: The movable outer tube and the unsealing piston are respectively sleeved on the outer wall of the central tube, the lower end of the outer tube is connected with the lower rubber cylinder seat, and the upper end of the outer tube is provided with a plurality of split slots; the lower end of the unsealing piston is provided with a plurality of split claws, which are correspondingly embedded in the split slots; The lock sleeve is arranged between the upper connector and the upper rubber cylinder seat, and the inner wall of the lock sleeve is provided with lock teeth; the elastic lock ring is arranged in the lock sleeve and is sleeved on the middle section of the split claw of the unsealing piston, and the outer wall lock teeth of the elastic lock ring are connected with the lock teeth of the lock sleeve; The inner wall of the elastic lock ring is provided with inner wall lock teeth, and the seat locking teeth on the outer wall of the upper end of the outer tube can be locked; the inner wall of the elastic lock ring is also provided with a plurality of inclined surface guide grooves, and the lower section of the split claw of the unsealing piston is provided with a corresponding variable diameter structure expanding in diameter from top to bottom, and when the unsealing piston moves upward, the variable diameter structure radially expands the elastic lock ring, so that the elastic lock ring is loosened from the outer tube.

2. The repeatable set annulus pressure unsetting packer of claim 1, wherein: It also includes a liquid cylinder, the lower end of the liquid cylinder is connected with the lower connector, and the hydraulic cylinder II formed between the inner wall of the liquid cylinder and the outer wall of the central tube is provided with an upper piston movable upward and downward, the upper piston is connected with the lower end of the lower rubber cylinder seat through a shear pin, and the upper piston is connected with the lower end of the lower rubber cylinder seat through a shear pin; The side wall of the central tube is also provided with a lower pressure transmission hole II, which connects the lower end of the upper piston and transmits the hydraulic pressure upward, and the upper piston can move upward and push the lower rubber cylinder seat upward.

3. The repeatable-set annular pressure unsetting packer of claim 2, wherein: The inner wall of the upper part of the upper piston and the outer wall of the central tube form a hydraulic cylinder I; The side wall of the central tube is provided with a lower pressure transmission hole I, which connects the hydraulic cylinder I and transmits the hydraulic pressure to the lower end of the lower rubber cylinder seat, and pushes it upward.

4. The repeatable set annulus pressure unsetting packer of claim 3, wherein: The lower piston movable upward and downward is arranged in the hydraulic cylinder III formed between the lower connector and the central tube, and the upper end of the lower piston abuts against the lower end of the upper piston; The side wall of the central tube is also provided with a lower pressure transmission hole III, which connects the lower end of the lower piston and transmits the hydraulic pressure upward.

5. The retrievable annular pressure unseating packer of claim 1, wherein: The side wall of the upper section of the central tube is provided with an upper pressure transmission hole, which connects the upper end of the unsealing piston and transmits the hydraulic pressure downward.

6. The repeatable-set annular pressure unsetting packer of claim 5, wherein: The side wall of the upper rubber cylinder seat is provided with an unsealing through hole, which connects the lower end of the unsealing piston.

7. The retrievable annular pressure unseating packer of claim 1, wherein: The lock sleeve and the elastic lock ring are also limited by screws.

8. The retrievably-set annular pressure-release packer of claim 1, wherein: The split claws, split slots and inclined surface guide grooves are uniformly distributed along the circumference.

9. The repeatable-set annular pressure unsetting packer of claim 8, wherein: The number of split claws, split slots and inclined surface guide grooves is four.

10. The retrievable annular pressure unseating packer of any of claims 1-9, wherein: Sealing rings are respectively arranged between the inner wall of the upper part of the unsealing piston, the outer wall of the unsealing piston and the outer wall of the central tube, and the inner wall of the upper connector; And / or, sealing rings are arranged between the inner wall of the lower rubber cylinder seat and the outer wall of the outer tube; And / or, sealing rings are respectively arranged between the inner wall and the outer wall of the lower part of the upper piston, the outer wall of the central tube and the inner wall of the liquid cylinder, and between the inner wall of the upper part of the upper piston and the outer wall of the central tube; And / or, sealing rings are respectively arranged between the inner wall and the outer wall of the lower part of the lower piston, the outer wall of the central tube and the inner wall of the lower connector, and between the outer wall of the upper part of the lower piston and the inner wall of the liquid cylinder.

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