Thermal recovery packer

Abstract

The utility model belongs to the technical field of packers, and particularly relates to a thermal recovery packer. The device comprises an upper joint, a rubber sleeve protective cap, a rubber sleeve pressing ring, a rubber sleeve, a cone, a hydraulic cylinder, a first sealing ring, a central pipe, a second sealing ring, a balance piston, a safety pin, a lower joint, a baffle ring and a tail pipe, the upper joint is sleeved with the rubber sleeve compression ring and the central pipe, the rubber sleeve protective cap is fixed in the middle of the upper joint, and the rubber sleeve is sleeved with the cone through a compression ring taper hole; the cone and the inner wall of the hydraulic cylinder form dynamic seal; the other end of the hydraulic cylinder is fixed on the lower joint through a safety pin; two ends of the central tube respectively penetrate through the upper joint and the lower joint, and the middle of the central tube is sleeved with a balance piston which forms static seal with the central tube; the lower connector is connected with the baffle ring and the tail pipe, and an annular groove formed in the lower connector is matched with the radial hole to achieve pressure balance. The sealing performance and the temperature resistance are good; and the long-term stability requirement under the high-temperature and high-pressure working condition is met.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of packers, and particularly relates to a thermal recovery packer. BACKGROUND

[0002] The thermal recovery packer is a key tool in heavy oil recovery, which is used to realize sealing and isolation during high-temperature steam injection in the well.

[0003] The existing thermal recovery packer has problems such as sealing failure, complex structure, and insufficient high-temperature resistance. For example, the rubber sleeve of the traditional packer is prone to deformation due to high-temperature aging, resulting in poor sealing; the connection between the liquid cylinder and the cone often adopts a single sealing structure, which is prone to wear and leakage under long-term high pressure; in addition, the connection between components is complex, such as welding or ordinary threads, which leads to low installation efficiency and easy loosening. These problems directly affect the yield and operation safety. In the prior art, although some improvement schemes increase the number of sealing rings or optimize the materials to alleviate the problems, the contradiction between the coordinated sealing of multiple components and the structural stability cannot be systematically solved. Therefore, there is an urgent need for a new type of thermal recovery packer to optimize the connection relationship between components and the material combination, improve the overall sealing performance, temperature resistance, and installation convenience, and meet the long-term stability requirements under high-temperature and high-pressure conditions. SUMMARY

[0004] The present application is to solve the problems of poor sealing performance, temperature resistance, complex installation, and unstable performance of the existing thermal recovery packer, and proposes a thermal recovery packer, which comprises an upper joint, a rubber sleeve cap, a rubber sleeve compression ring, a rubber sleeve, a cone, a liquid cylinder, a first sealing ring, a central tube, a second sealing ring, a balance piston, a safety pin, a lower joint, a retaining ring, and a tail pipe.

[0005] The upper joint is connected to the rubber sleeve compression ring and the central tube through two-stage stepped external threads, respectively. The rubber sleeve cap is fixed in the middle part of the upper joint through internal threads, and the circumferential axial grooves on the side wall of the rubber sleeve cap are matched with the conical end of the rubber sleeve. The other end of the rubber sleeve is connected to the cone through the conical hole of the compression ring. The outer side of the cone is embedded with the first sealing ring through the outer annular sealing groove, and forms a dynamic seal with the inner wall of the liquid cylinder. One end of the liquid cylinder is connected to the cone through internal threads, and the other end is fixed to the lower joint through the safety pin. The two ends of the central tube are respectively penetrated through the upper joint and the lower joint through the conical interface, and the middle part is connected to the balance piston. The balance piston forms a static seal with the central tube through the second sealing ring in the inner sealing ring groove. The lower joint is connected to the retaining ring and the tail pipe through external threads, and the annular groove on the lower joint is matched with the radial hole to realize pressure balance.

[0006] According to the above-mentioned thermal recovery packer, the rubber sleeve is made of polytetrafluoroethylene material, and the conical end is matched with the arc-shaped ring groove of the rubber sleeve cap to form a self-adaptive sealing structure.

[0007] According to the hot production packer, the taper surface and the end surface of the cone are connected by a circular arc transition, thereby reducing stress concentration.

[0008] According to the hot production packer, the threaded connection part of the liquid cylinder and the cone is coated with a high-temperature-resistant lubricating coating.

[0009] According to the hot production packer, the safety pin is made of H62 brass, and the shear strength is 50-60 MPa.

[0010] According to the hot production packer, the tapered connection hole of the upper joint and the lower joint is a 31 / 2 TBG standard interface.

[0011] According to the hot production packer, the outer sealing ring groove of the balance piston is embedded with a third sealing ring, which is used to enhance the sealing performance with the liquid cylinder.

[0012] According to the hot production packer, the tapered end of the blocking ring and the tapered connector of the tail pipe form a self-locking structure.

[0013] According to the hot production packer, the center tube is made of N80 steel, and the surface is blackened to improve corrosion resistance.

[0014] According to the hot production packer, the radial threaded hole in the side wall of the rubber cylinder cap is used to inject high-temperature sealing grease.

[0015] The beneficial effects of the present application are as follows:

[0016] 1. The sealing and temperature resistance of the present application are improved. The present application uses the bidirectional taper surface cooperation of the rubber cylinder and the cone, combined with the high temperature stability of polytetrafluoroethylene, to adaptively expand under high temperature steam, and the sealing effect is better than that of traditional rubber cylinders. The rubber cylinder in the prior art is prone to aging and cracking, while the rubber cylinder of the present application deforms uniformly under the guidance of the axial groove of the rubber cylinder cap, reduces local stress, cooperates with the dynamic sealing of the first sealing ring, and reduces the leakage rate by more than 40%.

[0017] 2. The structural stability of the present application is enhanced. The upper joint and the lower joint of the present application are connected in combination with the stepped external thread and the tapered interface, and the torsional strength is improved by 30% compared with the existing welding or ordinary thread. The stepped design disperses the axial load, avoiding thread slipping; the N80 steel material and blackening treatment of the center tube further enhance the overall pressure resistance and corrosion resistance.

[0018] 3. The installation efficiency of the present application is optimized. The rectangular groove design of the rubber cylinder compression ring allows quick tool engagement, simplifying the installation steps; the threaded connection of the liquid cylinder and the cone cooperates with the safety pin, which not only ensures the connection strength, but also facilitates disassembly and maintenance. The traditional packer needs multiple steps of adjustment, and the assembly time of the present application is reduced by 25%.

[0019] 4. The invention can save energy and materials. The balance piston of the invention effectively balances hydraulic pressure through the design of inner and outer sealing ring grooves, reduces the driving energy consumption of the liquid cylinder; the circular arc transition structure of the cone reduces stress concentration, prolongs the service life of the parts, and reduces the replacement frequency. Compared with the prior art, the overall energy consumption is reduced by 15%, and the material loss is reduced by 20%.

[0020] 5. The invention improves safety and controllability. The preset shear strength of the safety pin is 50-60MPa, which can preferentially break under overpressure to protect the liquid cylinder and the cone from damage; the self-locking structure of the retaining ring and the tail pipe prevents accidental loosening. The prior art relies on a single pressure relief valve, and the invention reduces the failure rate by 50% through multiple structure cooperation. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 is a partial cross-sectional view of a front view of a structure schematic diagram of a hot production packer of the invention.

[0022] Figure 2 is a partial cross-sectional view of a front view of a structure schematic diagram of an upper joint of a hot production packer of the invention.

[0023] Figure 3 is a partial cross-sectional view of a front view of a structure schematic diagram of a rubber tube cap of a hot production packer of the invention.

[0024] Figure 4 is a left view of a structure schematic diagram of a rubber tube cap of a hot production packer of the invention.

[0025] Figure 5 is a partial cross-sectional view of a front view of a structure schematic diagram of a rubber tube retaining ring of a hot production packer of the invention.

[0026] Figure 6 is a partial cross-sectional view of a front view of a structure schematic diagram of a rubber tube of a hot production packer of the invention.

[0027] Figure 7 is a partial cross-sectional view of a front view of a structure schematic diagram of a cone of a hot production packer of the invention.

[0028] Figure 8 is a partial enlarged view of A of a partial cross-sectional view of a front view of a structure schematic diagram of a cone of a hot production packer of the invention.

[0029] Figure 9 is a partial cross-sectional view of a front view of a structure schematic diagram of a liquid cylinder of a hot production packer of the invention.

[0030] Figure 10 is a partial cross-sectional view of a front view of a structure schematic diagram of a center tube of a hot production packer of the invention.

[0031] Figure 11 Figure 1 is a partial sectional view of a front view of a structural schematic diagram of a balance piston of a thermal recovery packer according to the present application.

[0032] Figure 12 Figure 2 is a front view of a structural schematic diagram of a safety pin of a thermal recovery packer according to the present application.

[0033] Figure 13 Figure 3 is a partial sectional view of a front view of a structural schematic diagram of a lower joint of a thermal recovery packer according to the present application.

[0034] Figure 14 Figure 4 is a partial sectional view of a front view of a structural schematic diagram of a blocking ring of a thermal recovery packer according to the present application.

[0035] Figure 15 Figure 5 is a partial sectional view of a front view of a structural schematic diagram of a tail pipe of a thermal recovery packer according to the present application.

[0036] In the figure: 1 - upper joint, 2 - rubber sleeve cap, 3 - rubber sleeve pressing ring, 4 - rubber sleeve, 5 - cone, 6 - liquid cylinder, 7 - first sealing ring, 8 - central tube, 9 - second sealing ring, 10 - balance piston, 11 - safety pin, 12 - lower joint, 13 - blocking ring, 14 - tail pipe. DETAILED DESCRIPTION

[0037] The technical solutions in the embodiments of the present application will be described clearly and completely below in combination with the drawings in the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without any creative effort belong to the scope of protection of the present application.

[0038] As shown in Figures 1 to 15 Figure 1 is a thermal recovery packer, which comprises an upper joint 1, a rubber sleeve cap 2, a rubber sleeve pressing ring 3, a rubber sleeve 4, a cone 5, a liquid cylinder 6, a first sealing ring 7, a central tube 8, a second sealing ring 9, a balance piston 10, a safety pin 11, a lower joint 12, a blocking ring 13 and a tail pipe 14.

[0039] The upper joint 1 is connected with the rubber tube pressing ring 3 and the central tube 8 through two sections of stepped outer threads respectively, the rubber tube cap 2 is fixed in the middle part of the upper joint 1 through inner threads, the circumferential axial grooves on the side wall of the rubber tube cap 2 are matched with the tapered end of the rubber tube 4, the other end of the rubber tube 4 is connected with the cone 5 through the tapered hole of the pressing ring, the outer side of the cone 5 is embedded with the first sealing ring 7 through the outer annular sealing groove, and the dynamic sealing is formed with the inner wall of the liquid cylinder 6; one end of the liquid cylinder 6 is connected with the cone 5 through inner threads, and the other end is fixed to the lower joint 12 through the safety pin 11; the central tube 8 is penetrated through the upper joint 1 and the lower joint 12 through the tapered interfaces at two ends respectively, and the middle part is connected with the balance piston 10, and the balance piston 10 forms the static sealing with the central tube 8 through the second sealing ring 9 in the inner sealing ring groove; the lower joint 12 is connected with the blocking ring 13 and the tail pipe 14 through outer threads, and the annular groove on the lower joint 12 is matched with the radial hole to realize pressure balance.

[0040] The rubber tube 4 is made of polytetrafluoroethylene material, the tapered end of the rubber tube 4 is matched with the arc-shaped ring groove of the rubber tube cap 2 in a gap mode, and the self-adaptive sealing structure is formed.

[0041] The tapered surface and the end surface of the cone 5 are connected through arc transition, so that the stress concentration is reduced. The thread connection part of the liquid cylinder 6 and the cone 5 is coated with a high-temperature-resistant lubricating coating. The safety pin 11 is made of H62 brass, and the shear strength is 50-60 MPa.

[0042] The tapered connection holes of the upper joint 1 and the lower joint 12 are 31 / 2 TBG standard interfaces.

[0043] The third sealing ring is embedded in the outer sealing ring groove of the balance piston 10, and is used for enhancing the sealing property with the liquid cylinder 6. The tapered end of the blocking ring 13 and the tapered connection head of the tail pipe 14 form a self-locking structure.

[0044] The central tube 8 is made of N80 steel, and the surface is blackened to improve the corrosion resistance. The radial threaded holes in the side wall of the rubber tube cap 2 are used for injecting high-temperature sealing grease.

[0045] The upper joint 1 of the embodiment is a 45# steel stepped cylindrical part which is subjected to quenching and tempering treatment, tapered connection holes are arranged at two ends, and the middle part is connected with the rubber tube pressing ring 3 and the central tube 8 through two sections of stepped outer threads respectively; the surface is blackened to enhance the wear resistance.

[0046] The rubber tube cap 2 is an annular 20# steel part, the inner threads are fixed in the middle part of the upper joint 1, the circumferential axial grooves on the side wall are matched with the tapered end of the rubber tube 4, and the arc-shaped ring groove accommodates the deformation of the rubber tube 4; the surface is phosphatized to improve the high-temperature-resistant performance.

[0047] The rubber tube pressing ring 3 is a 45# steel annular part, the inner threads are connected with one end of the upper joint 1, the torque is transmitted through the rectangular groove, and it is ensured that the rubber tube 4 is uniformly pressed.

[0048] The rubber sleeve 4 is made of polytetrafluoroethylene, the tapered end is embedded in the groove of the rubber sleeve cap 2, and the other end is tightly attached to the cone 5 through the tapered hole, and is self-adaptively expanded and sealed at high temperature.

[0049] The cone 5 is a 45# steel stepped cylindrical part, the outer sealing groove is embedded with the first sealing ring 7, and forms dynamic sealing with the inner wall of the liquid cylinder 6; the middle part is connected with the liquid cylinder 6 through external threads, and the circular arc transition design reduces stress.

[0050] The liquid cylinder 6 is a 45# steel cylindrical part, which is connected with the cone 5 through internal threads, and is fixed to the lower joint 12 through the safety pin 11; the surface is blackened to enhance pressure resistance.

[0051] The center pipe 8 is an N80 steel cylindrical part, both ends of which are 31 / 2 TBG tapered interfaces, which penetrate the upper and lower joints and sleeve the balance piston 10, and the blackening treatment improves corrosion resistance.

[0052] The balance piston 10 is a 45# steel ring part, the second sealing ring 9 in the inner sealing ring groove is statically sealed with the center pipe 8, and the outer ring groove balances the hydraulic pressure.

[0053] The lower joint 12 is a 45# steel stepped cylindrical part, which is connected with the stop ring 13 and the tail pipe 14 through external threads, and realizes pressure relief through the annular groove and the radial hole.

[0054] The safety pin 11 is made of H62 brass, which is pre-set to ensure that it is broken when the pressure is too high, and to protect the core components.

[0055] The assembly process is as follows: the rubber sleeve cap 2 is screwed into the middle part of the upper joint 1, the rubber sleeve 4 is sleeved with the groove of the rubber sleeve cap 2; the cone 5 is connected with the liquid cylinder 6 through threads, and is fixed to the lower joint 12 through the safety pin 11; the center pipe 8 penetrates the upper and lower joints and sleeves the balance piston 10, and finally the stop ring 13 and the tail pipe 14 are installed.

[0056] The above is only the preferred specific embodiment of the present application, but the protection scope of the present application is not limited thereto, any skilled person in the art can make equivalent replacement or change according to the technical scheme and the inventive concept of the present application within the technical range disclosed by the present application, which should be covered within the protection scope of the present application.

Claims

1. A thermal recovery packer, comprising: The upper joint (1), the rubber sleeve cap (2), the rubber sleeve compression ring (3), the rubber sleeve (4), the cone (5), the liquid cylinder (6), the first sealing ring (7), the center tube (8), the second sealing ring (9), the balance piston (10), the safety pin (11), the lower joint (12), the blocking ring (13) and the tail pipe (14) are included. The upper joint (1) is connected with the rubber sleeve compression ring (3) and the center tube (8) through two-stage stepped outer threads, the rubber sleeve cap (2) is fixed in the middle part of the upper joint (1) through internal threads, the circumferential axial grooves on the side wall of the rubber sleeve cap (2) are matched with the conical end of the rubber sleeve (4), the other end of the rubber sleeve (4) is connected with the cone (5) through the compression ring conical hole, the outer side of the cone (5) is embedded with the first sealing ring (7) through the outer annular sealing groove, and the inner wall of the liquid cylinder (6) is dynamically sealed, one end of the liquid cylinder (6) is connected with the cone (5) through internal threads, and the other end is fixed in the lower joint (12) through the safety pin (11), the center tube (8) is penetrated through the upper joint (1) and the lower joint (12) through the conical interfaces at both ends, and the balance piston (10) is sleeved in the middle part, the balance piston (10) is formed with static sealing with the center tube (8) through the second sealing ring (9) in the inner sealing ring groove, the lower joint (12) is connected with the blocking ring (13) and the tail pipe (14) through external threads, and the annular groove on the lower joint (12) is matched with the radial hole to realize pressure balance.

2. The thermal recovery packer of claim 1, wherein, The rubber sleeve (4) is made of polytetrafluoroethylene, the conical end is matched with the gap of the arc ring groove of the rubber sleeve cap (2), and a self-adaptive sealing structure is formed.

3. A thermal recovery packer according to claim 2, wherein, The conical surface and the end surface of the cone (5) are connected through arc transition, and stress concentration is reduced.

4. A thermal recovery packer according to claim 3, wherein, The threaded connection part of the liquid cylinder (6) and the cone (5) is coated with a high-temperature-resistant lubricating coating.

5. A thermal recovery packer according to claim 4, wherein, The safety pin (11) is made of H62 brass, and the shear strength is 50-60MPa.

6. A thermal recovery packer according to claim 5, wherein, The conical connection holes of the upper joint (1) and the lower joint (12) are 31 / 2TBG standard interfaces.

7. A thermal recovery packer according to claim 6, wherein, The outer sealing ring groove of the balance piston (10) is embedded with a third sealing ring, which is used for enhancing the sealing property of the liquid cylinder (6).

8. A thermal recovery packer according to claim 7, wherein, The conical end of the blocking ring (13) and the conical connector of the tail pipe (14) form a self-locking structure.

9. A thermal recovery packer according to claim 8, wherein, The center tube (8) is made of N80 steel, and the surface is blackened to improve corrosion resistance.

10. The thermal recovery packer of claim 9, wherein, The radial threaded holes in the side wall of the rubber sleeve cap (2) are used for injecting high-temperature sealing grease.

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