Hydraulic self-feedback repeatable setting packer

Abstract

The present application relates to the technical field of downhole tools, and particularly relates to a hydraulic self-feedback repeatable setting packer to relieve setting stability of the packer, which comprises an upper joint, an inner tube, an outer tube and a rubber sleeve, the lower part of the rubber sleeve is provided with a first pressure applying module and a second pressure applying module; the first pressure applying module and the second pressure applying module are sequentially arranged in the lower part of the rubber sleeve from bottom to top; the upper joint is threadedly connected with the inner tube and the outer tube respectively; the inner tube is communicated with the first pressure applying module, and after pressure boosting, the rubber sleeve is extruded to expand and contact with the well wall; the outer tube is communicated with the second pressure applying module, and after setting is completed, the upper annular pressure can extrude the rubber sleeve through the second pressure applying module to expand and contact with the well wall. After setting is completed, the upper annular pressure can continuously act on the compression tube through the second pressure applying module, forming a self-feedback mechanism of "the higher the pressure, the tighter the sealing", and significantly enhancing the sealing stability under high pressure difference working conditions.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of downhole tools, in particular to a hydraulic self-feedback repeatable setting packer. BACKGROUND

[0002] In the process of oilfield development, in order to improve the productivity of low-yield or low-permeability layers, conventional stimulation measures such as separate layer fracturing and acidizing are often used, the key of which is to realize effective isolation of the target layer and other layers to prevent high-pressure operation fluid from channeling into non-target layers. For this purpose, compression packers are widely used in separate layer strings, which rely on tubing pressure to set and form a seal in the tubing-casing annulus.

[0003] However, the conventional compression packer has obvious defects in structural design: the setting force comes from the pressure established in the tubing, and once the stimulation operation is completed and the tubing pressure is released, the packer is prone to automatic retraction and unsealing due to the lack of effective mechanical locking or anchoring mechanism, resulting in interlayer sealing failure. Especially under the conditions of multi-layer operation or high pressure difference, the interlayer channel formed after unsealing can cause the channeling of formation fluid, not only weakening the effect of stimulation measures, but also possibly causing interlayer interference, water channeling or gas channeling and other secondary problems, seriously affecting the production efficiency and development life of the oil well. In addition, the sealing element of some packers is prone to aging or creep under the influence of temperature and pressure fluctuations during long-term service in the well, further increasing the risk of sealing reliability decline.

[0004] Therefore, how to solve the problem of automatic unsealing after pressure release under the premise of ensuring normal setting of the packer, and improve its stability and sealing durability under complex working conditions, has become a key technical bottleneck that needs to be broken through in the current separate layer stimulation technology. SUMMARY

[0005] To alleviate the above technical problems, the technical scheme provided by the present application is as follows:

[0006] The present application provides a hydraulic self-feedback repeatable setting packer, which comprises an upper joint, an inner tube, an outer tube and a rubber sleeve, and the lower part of the rubber sleeve is sequentially provided with a primary pressure applying module and a secondary pressure applying module from bottom to top.

[0007] The upper joint is threadedly connected with the inner tube and the outer tube respectively;

[0008] The inner tube is in communication with the primary pressure applying module, and after pressure rise, the rubber sleeve is extruded to expand and contact the well wall;

[0009] The outer tube is in communication with the secondary pressure applying module, and after setting is completed, the annulus pressure can extrude the rubber sleeve to expand and contact the well wall through the secondary pressure applying module.

[0010] Further,

[0011] The primary pressure applying module comprises a setting piston, a sealing tube and a connecting tube;

[0012] The inner tube is provided with two groups of first pressure transmission holes in the vertical direction;

[0013] The setting piston and the sealing tube are sequentially sleeved on the inner tube from top to bottom;

[0014] One group of the first pressure transmission holes is arranged corresponding to the groove of the setting piston, and the other group of the first pressure transmission holes is arranged corresponding to the groove of the sealing tube;

[0015] The connecting tube is sleeved on the outside of the setting piston and the sealing tube;

[0016] The setting piston is in sliding connection with the inner tube;

[0017] The sealing tube is fixedly connected with the inner tube through a fixing ring.

[0018] Further,

[0019] After the inner tube is pressurized, the setting piston can move upwards and push the compression tube to extrude the rubber sleeve, so that the rubber sleeve is expanded to contact the well wall.

[0020] Further,

[0021] The secondary pressure applying module comprises a first cavity and a second cavity;

[0022] The upper joint is provided with a second pressure transmission hole;

[0023] The compression tube is sleeved on the outer tube;

[0024] The first cavity is arranged between the outer tube and the inner tube;

[0025] The second cavity is arranged between the outer tube and the compression tube;

[0026] The second pressure transmission hole, the first cavity and the second cavity are sequentially communicated.

[0027] Further,

[0028] After the rubber sleeve is expanded and the setting is completed, when the pressure on the well is increased, the pressure is transmitted from the second pressure transmission hole into the second cavity, so that the compression tube is pressed to move upwards.

[0029] Further,

[0030] Further comprising a locking mechanism;

[0031] The locking mechanism comprises a locking pin and a locking ring;

[0032] The locking pin and the locking ring are arranged on the side wall of the inner tube, respectively;

[0033] The compression tube is provided with a first groove and a second groove matched with the locking pin and the locking ring.

[0034] Further,

[0035] The locking pin is provided with a compression spring away from one side of the compression pipe.

[0036] Further,

[0037] The first groove and the second groove have outwardly expanding inclined surfaces respectively.

[0038] Further,

[0039] The compression pipe and the inner pipe are provided with a first support pipe and a second support pipe;

[0040] The first support pipe and the second support pipe have a first gap therebetween;

[0041] The second support pipe and the inner pipe have a second gap therebetween;

[0042] The first cavity is provided with a third pressure transmission hole;

[0043] The third pressure transmission hole is communicated with the second gap.

[0044] Further,

[0045] The compression pipe is provided with a fourth pressure transmission hole;

[0046] After the compression pipe is moved upward, the fourth pressure transmission hole is communicated with the first gap.

[0047] The beneficial effects of the hydraulic self-feedback repeatable setting packer in the application are analyzed as follows:

[0048] The application provides a hydraulic self-feedback repeatable setting packer, which comprises an upper joint, an inner pipe, an outer pipe and a rubber sleeve, the lower part of the rubber sleeve is provided with a first pressure applying module and a second pressure applying module; the first pressure applying module and the second pressure applying module are sequentially arranged from bottom to top in the lower part of the rubber sleeve; the upper joint is threadedly connected with the inner pipe and the outer pipe respectively; the inner pipe is communicated with the first pressure applying module, and after pressure rising, the inner pipe extrudes the rubber sleeve to make it expand and contact with the well wall; the outer pipe is communicated with the second pressure applying module, and after setting is completed, the upper annular space pressure can extrude the rubber sleeve to make it expand and contact with the well wall through the second pressure applying module.

[0049] By arranging the first pressure applying module and the second pressure applying module, the synergistic effect of internal pressure setting and upper annular space pressure self-feedback sealing is realized, and the problem that the traditional packer is prone to retract and unseal after pressure release is effectively solved. During setting, the inner pipe pressurizes to drive the first pressure applying module to push the compression pipe, so that the rubber sleeve expands to realize reliable sealing; after setting is completed, the upper annular space pressure can continuously act on the compression pipe through the second pressure applying module (through the second pressure transmission hole, the first cavity and the second cavity), forming a self-feedback mechanism of "the higher the pressure, the tighter the sealing", which significantly enhances the sealing stability under high pressure difference working conditions. BRIEF DESCRIPTION OF DRAWINGS

[0050] To more clearly illustrate the technical solutions in the specific embodiments or related technologies of the present invention, the drawings used in the description of the specific embodiments or related technologies 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.

[0051] Figure 1 A schematic diagram of the structure of a hydraulically self-feedback repositionable packer provided in an embodiment of the present invention;

[0052] Figure 2 for Figure 1 A magnified view of part A in the diagram;

[0053] Figure 3 for Figure 1 A magnified view of part B in the diagram;

[0054] Figure 4 for Figure 1 A magnified view of part of C;

[0055] Figure 5 for Figure 1 A magnified view of part of D;

[0056] Figure 6 A schematic diagram of the lower structure of a hydraulically self-feedback repositionable packer provided for an embodiment of the present invention;

[0057] Figure 7 This is a schematic diagram of the locking ring.

[0058] icon:

[0059] 100 - Upper connector; 110 - Second pressure transmission hole;

[0060] 200 - Inner tube; 210 - First pressure transmission hole;

[0061] 300-outer tube;

[0062] 400-Glue Shot;

[0063] 510-Setting piston; 520-Sealing tube; 530-Connecting tube; 540-Compression tube; 541-First groove; 542-Second groove; 543-First support tube; 544-Second support tube; 545-First gap; 546-Second gap; 547-Fourth pressure transmission hole;

[0064] 610 - First cavity; 611 - Third pressure transmission hole; 620 - Second cavity;

[0065] 700 - locking mechanism; 710 - locking pin; 711 - compression spring; 720 - locking ring. DETAILED DESCRIPTION

[0066] Conventional packers are prone to automatic retraction and unsealing after pressure release due to the lack of effective mechanical locking or anchoring mechanisms, resulting in the failure of interlayer sealing. Especially in multilayer operation or high pressure difference conditions, the interlayer channel formed after unsealing can cause the channeling of formation fluid, not only weakening the effect of stimulation treatment, but also possibly causing interlayer interference, water channeling or gas channeling and other secondary problems, seriously affecting the production efficiency and development life of oil wells. In addition, the sealing elements of some packers are prone to aging or creep under the influence of temperature and pressure fluctuations during long-term service in the well, further increasing the risk of sealing reliability decline.

[0067] Therefore, as shown in the present scheme, a hydraulic self-feedback repeatable setting packer is provided to alleviate the above problems. Figures 1 to 6

[0068] The packer includes an upper joint 100, an inner tube 200, an outer tube 300, and a rubber sleeve 400. The lower part of the rubber sleeve 400 is sequentially provided with a primary pressure applying module and a secondary pressure applying module from bottom to top;

[0069] The upper joint 100 is threadedly connected with the inner tube 200 and the outer tube 300, respectively;

[0070] The inner tube 200 is in communication with the primary pressure applying module, and after pressure rise, it extrudes the rubber sleeve 400 to make it expand and contact the well wall;

[0071] The outer tube 300 is in communication with the secondary pressure applying module, and after setting is completed, the upper annular pressure can extrude the rubber sleeve 400 through the secondary pressure applying module to make it expand and contact the well wall.

[0072] Specifically, when the pressure inside the inner tube 200 rises, it can trigger the primary pressure applying module to make the rubber sleeve 400 expand under pressure to achieve the setting of the packer; after the setting is completed, when the upper annular pressure rises, the pressure is transmitted from the outer tube 300 to the secondary pressure applying module, which acts on the rubber sleeve 400 in the same direction, avoiding the unsealing of the rubber sleeve 400 due to pressure difference.

[0073] In the present scheme, as shown in Figure 1 , Figure 4 and Figure 5 , the primary pressure applying module includes a setting piston 510, a sealing tube 520, and a connecting tube 530;

[0074] The inner tube 200 is provided with two groups of first pressure transmission holes 210 in the vertical direction;

[0075] The setting piston 510 and the sealing tube 520 are sequentially sleeved with the inner tube 200 from top to bottom; ​

[0076] A group of first pressure transmission holes 210 are arranged corresponding to the groove of the setting piston 510, and another group of first pressure transmission holes 210 are arranged corresponding to the groove of the sealing tube 520;

[0077] The connecting tube 530 is sleeved on the outside of the setting piston 510 and the sealing tube 520;

[0078] The setting piston 510 is in sliding connection with the inner tube 200;

[0079] The sealing tube 520 is fixedly connected with the inner tube 200 through a fixing ring;

[0080] After the inner tube 200 is pressurized, the setting piston 510 can move upward and push the compression tube 540 to extrude the rubber sleeve 400, so that the rubber sleeve 400 is inflated and in contact with the well wall.

[0081] Specifically, the setting piston 510 and the sealing tube 520 are respectively in sliding connection with the inner tube 200, and each of them corresponds to a group of first pressure transmission holes 210. When the pressure in the inner tube 200 rises, the pressure is transmitted to the setting piston 510 and the sealing tube 520 through the two groups of first pressure transmission holes 210 respectively, so that the two together move upward with the connecting tube 530, and the connecting tube 530 pushes the compression tube 540 above it to move upward and extrude the rubber sleeve 400 to expand, so as to realize the setting of the packer;

[0082] More preferably, the lower part of the inner tube 200 is provided with a lower connector, and the lower connector is fixedly connected with the connecting tube 530 through a shear pin. When the pressure in the inner tube 200 reaches the setting requirement, the shear pin is broken, so that the connecting tube 530 moves upward, so as to avoid the accidental triggering during the process of lowering the packer into the well.

[0083] In this scheme, as shown in Figure 1 、 Figure 2 and Figure 3 , the secondary pressure applying module includes a first cavity 610 and a second cavity 620;

[0084] The upper connector 100 is provided with a second pressure transmission hole 110;

[0085] The compression tube 540 is sleeved with the outer tube 300;

[0086] The first cavity 610 is arranged between the outer tube 300 and the inner tube 200;

[0087] The second cavity 620 is arranged between the outer tube 300 and the compression tube 540;

[0088] The second pressure transmission hole 110, the first cavity 610 and the second cavity 620 are sequentially communicated;

[0089] When the well pressure rises after the rubber sleeve 400 is inflated and set against the well wall, the pressure is transmitted from the second pressure transmission hole 110 into the second cavity 620, causing the compression tube 540 to be pressed upward.

[0090] Specifically, after the rubber sleeve 400 is inflated and set against the well wall by pressurizing the inner tube 200, the upper annular pressure of the packer may rise during the construction process. Since the second pressure transmission hole 110, the first cavity 610 and the second cavity 620 are sequentially connected, the rising pressure of the upper annulus can be transmitted to the second cavity 620 and act on the compression tube 540 from bottom to top, thereby continuously extruding the rubber sleeve 400 and effectively preventing the problem of packer setting failure caused by excessive upper pressure.

[0091] In this scheme, as shown in Figure 1 and Figure 6 , it further comprises a locking mechanism 700;

[0092] The locking mechanism 700 comprises a locking pin 710 and a locking ring 720;

[0093] The locking pin 710 and the locking ring 720 are respectively arranged on the side wall of the inner tube 200;

[0094] The compression tube 540 is provided with a first groove 541 and a second groove 542 matched with the locking pin 710 and the locking ring 720;

[0095] The side of the locking pin 710 away from the compression tube 540 is provided with a compression spring 711;

[0096] The first groove 541 and the second groove 542 respectively have outwardly expanding inclined surfaces.

[0097] Specifically, after the packer is set, the locking pin 710 is clamped into the first groove 541, and the locking ring 720 is clamped into the second groove 542. The locking pin 710 provides outwardly expanding pressure through the compression spring 711. The opening direction of the first groove 541 and the second groove 542 is designed as an outwardly expanding inclined surface, so as to facilitate the locking and unlocking of the locking mechanism 700. In addition, the first cavity 610 is in communication with the installation position of the locking pin 710, so that the pressure of the upper annulus can act on the locking pin 710 to enhance the locking effect of the locking pin 710 when the upper annular pressure rises.

[0098] In this scheme, as shown in Figure 1 and Figure 3 , a first support tube 543 and a second support tube 544 are arranged between the compression tube 540 and the inner tube 200;

[0099] The first support tube 543 and the second support tube 544 have a first gap 545 therebetween;

[0100] The second support pipe 544 has a second gap 546 with the inner pipe 200;

[0101] The first cavity 610 is provided with a third pressure transmission hole 611;

[0102] The third pressure transmission hole 611 is in communication with the second gap 546;

[0103] The compression pipe 540 is provided with a fourth pressure transmission hole 547;

[0104] After the compression pipe 540 moves upward, the fourth pressure transmission hole 547 is in communication with the first gap 545.

[0105] Specifically, after the packer is completed, the third pressure transmission hole 611 can transmit the pressure in the first cavity 610 to the second support pipe 544, so that the second support pipe 544 always drives the compression pipe 540 to move upward, to avoid the packer from being unsealed due to the upper pressure;

[0106] Before the packer is set, the fourth pressure transmission hole 547 is disconnected with the first gap 545, and after the compression pipe 540 moves upward, the fourth pressure transmission hole 547 is in communication with the first gap 545, so that when the pressure in the lower annulus of the packer is increased, the pressure can act on the compression pipe 540 to make the compression pipe 540 move upward, to maintain the setting state of the packer.

[0107] The scheme has at least the following beneficial effects:

[0108] The hydraulic self-feedback repeatable setting packer provided by the scheme realizes the synergistic effect of internal pressure setting and upper annulus pressure self-feedback sealing, effectively solves the problem that the traditional packer is prone to shrink and unseal after pressure release. During the setting process, the inner pipe pressurizes to drive the first pressure module to push the compression pipe, so that the rubber tube expands to achieve reliable sealing; after the setting is completed, the upper annulus pressure can continuously act on the compression pipe upward through the second pressure transmission hole, the first cavity, and the second cavity, forming a self-feedback mechanism of "the higher the pressure, the tighter the sealing", which significantly enhances the sealing stability under high pressure difference conditions. At the same time, the locking mechanism is automatically locked after setting in place, and through the cooperation of the locking pin and the inclined surface of the compression pipe groove, mechanical self-locking is realized under the action of the compression spring, preventing accidental unsealing caused by deformation of the sealing element, temperature fluctuation or pressure drop, and greatly improving the long-term reliability and reusability of the packer. In addition, the linkage design of the third pressure transmission hole and the fourth pressure transmission hole further optimizes the pressure transmission path, ensures that the lower annulus pressure can also participate in sealing, and comprehensively improves the adaptability and safety of the packer under complex well conditions, effectively avoids interlayer channeling, water and gas channeling and other secondary problems, and has important significance for improving the efficiency of stimulation measures and prolonging the development life of oil wells.

[0109] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, and are not intended to limit the present application; although the present application has been described in detail with reference to the above embodiments, those skilled in the art should understand that the technical solutions recorded in the above embodiments can be modified, or some or all of the technical features can be replaced by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A hydraulic self-feedback repeatable setting packer, comprising an upper joint (100), an inner tube (200), an outer tube (300) and a rubber sleeve (400), characterized in that: a first pressure module and a second pressure module are arranged at the lower part of the rubber sleeve (400); the upper joint (100) is threadedly connected with the inner tube (200) and the outer tube (300) respectively; the inner tube (200) is in communication with the first pressure module, and after pressure rising, the inner tube (200) extrudes the rubber sleeve (400) to make it expand and contact with the well wall; the outer tube (300) is in communication with the second pressure module, and after setting is completed, the annulus pressure can extrude the rubber sleeve (400) through the second pressure module to make it expand and contact with the well wall; the first pressure module comprises a setting piston (510), a sealing tube (520) and a connecting tube (530); the inner tube (200) is provided with two groups of first pressure transmission holes (210) in the vertical direction; the setting piston (510) and the sealing tube (520) are sequentially sleeved with the inner tube (200) from top to bottom; one group of the first pressure transmission holes (210) is arranged corresponding to the groove of the setting piston (510), and the other group of the first pressure transmission holes (210) is arranged corresponding to the groove of the sealing tube (520); the connecting tube (530) is sleeved outside the setting piston (510) and the sealing tube (520); the setting piston (510) is slidably connected with the inner tube (200); the sealing tube (520) is fixedly connected with the inner tube (200) through a fixing ring; after the inner tube (200) is pressurized, the setting piston (510) can move upwards and push the compression tube (540) to extrude the rubber sleeve (400), so that the rubber sleeve (400) expands and contacts with the well wall; the second pressure module comprises a first cavity (610) and a second cavity (620); the upper joint (100) is provided with a second pressure transmission hole (110); the compression tube (540) is sleeved with the outer tube (300); the first cavity (610) is arranged between the outer tube (300) and the inner tube (200); the second cavity (620) is arranged between the outer tube (300) and the compression tube (540); the second pressure transmission hole (110), the first cavity (610) and the second cavity (620) are sequentially communicated. 2.The hydraulic self-feedback repeatable setting packer according to claim 1, characterized in that: after the rubber sleeve (400) expands and completes setting with the well wall, when the annulus pressure rises, the pressure is transmitted from the second pressure transmission hole (110) into the second cavity (620), so that the compression tube (540) is pressed and moves upwards. 3.The hydraulic self-feedback repeatable setting packer according to claim 2, characterized in that: further comprising a locking mechanism (700); the locking mechanism (700) comprises a locking pin (710) and a locking ring (720); the locking pin (710) and the locking ring (720) are arranged on the sidewall of the inner tube (200) respectively. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ The compression pipe (540) is provided with a first groove (541) and a second groove (542) matched with the locking pin (710) and the locking ring (720).

4. The hydraulic self-feedback repeat-seating packer according to claim 3, characterized in that: The locking pin (710) is provided with a compression spring (711) away from one side of the compression pipe (540).

5. The hydraulic self-feedback repeat-seating packer according to claim 4, characterized in that: The first groove (541) and the second groove (542) have outwardly expanding inclined surfaces, respectively.

6. The hydraulic self-feedback repeat-seating packer according to claim 5, characterized in that: The compression pipe (540) is provided with a first support pipe (543) and a second support pipe (544) between the compression pipe (540) and the inner pipe (200); The first support pipe (543) and the second support pipe (544) have a first gap (545) therebetween; The second support pipe (544) and the inner pipe (200) have a second gap (546) therebetween; The first cavity (610) is provided with a third pressure transmission hole (611); The third pressure transmission hole (611) is communicated with the second gap (546).

7. The hydraulic self-feedback repeat-seating packer according to claim 6, characterized in that: The compression pipe (540) is provided with a fourth pressure transmission hole (547); After the compression pipe (540) is moved upward, the fourth pressure transmission hole (547) is communicated with the first gap (545).

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