High efficiency thermal recovery packer

Abstract

The application relates to a high-efficiency thermal recovery packer, relating to the technical field of oilfield downhole tools. The upper cooler and the lower cooler are both heat pipe structures: the upper cooler and the lower cooler are both closed cavity structures, the inner wall of the cavity is bonded with capillary substances, the cavity is filled with working liquid, and the air pressure in the cavity is in a negative pressure state. The packer has the beneficial effects that: when the lower cooling disc is heated, the outer circle of the lower cooling disc expands and is elastically attached to the inner wall of the casing, steam can be directly blocked below the rubber cylinder, the lower cooling disc directly contacts the casing, heat exchange between the lower cooling disc and the casing below the rubber cylinder is realized, the temperature of the casing contacting the rubber cylinder is reduced, the temperature of the rubber cylinder is further reduced, the sealing performance and service life of the rubber cylinder are improved, the annular groove of the outer circle of the lower cooling disc forms an annular space between the lower cooling disc and the casing, and heat insulation and elastic connection are facilitated.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of oilfield downhole tools, in particular to a high-efficiency thermal recovery packer. BACKGROUND

[0002] The thermal recovery packer is a common and key downhole tool in heavy oil exploitation, which is used for steam injection well sealing and separate layer steam injection, etc. The thermal recovery packer needs to withstand high temperature and high pressure, and has high performance requirements. After each steam injection, the well needs to be closed for a period of time to reduce the viscosity of the heavy oil, and then the heavy oil is exploited. The steam injection and well closing for a long time cause the rubber sleeve of the packer to age, and leakage occurs between the rubber sleeve and the casing. The leakage will continuously expand over time, and eventually leads to the failure of the packer. SUMMARY

[0003] In order to solve the problem that the current thermal recovery packer cannot maintain sealing for a long time, the present application provides a high-efficiency thermal recovery packer.

[0004] The technical scheme provided by the present application is as follows: a high-efficiency thermal recovery packer, comprising an upper joint and a lower joint, the upper joint is threadedly and sealingly connected to a central pipe, the lower part of the central pipe is threadedly and sealingly connected to the lower joint, the outer edge of the lower joint extends upward to form a cylinder sleeve, a piston is arranged between the cylinder sleeve and the central pipe, the piston is connected to the cylinder sleeve and the central pipe through a sealing assembly, and a liquid inlet hole is formed in the lower part of the sealing assembly of the piston.

[0005] An inner heat insulation sleeve is sleeved outside the central pipe, the inner heat insulation sleeve is arranged on the lower part of the upper joint, the upper part of the inner heat insulation sleeve is provided with a flange for positioning, an upper cooler and a lower cooler are sleeved outside the outer side of the inner heat insulation sleeve, the upper cooler is provided with two upper cooling discs, the lower cooler is provided with two lower cooling discs, the upper cooler is provided with an outer contact sleeve, the lower cooler is provided with an inner contact sleeve, the outer contact sleeve and the inner contact sleeve are inserted together, two nuts are threadedly connected to the lower part of the inner heat insulation sleeve, the two nuts are arranged at the lower part of the lower cooling disc, an outer heat insulation sleeve is sleeved outside the outer side of the outer contact sleeve and the inner contact sleeve, a rubber sleeve is sleeved outside the outer heat insulation sleeve, and the upper part of the outer heat insulation sleeve is provided with a flange which is clamped between the rubber sleeve and the upper cooling disc.

[0006] The upper cooler and the lower cooler are both heat pipe structures: the upper cooler and the lower cooler are both closed cavity structures, a capillary material is bonded to the inner wall of the cavity, a working liquid is filled in the cavity, and the air pressure in the cavity is in a negative pressure state.

[0007] The upper part of the piston is fixedly connected to a top rod, the number of the top rods is four and they are uniformly arranged in a circle, the lower cooling disc is provided with a through hole at the position of the top rod, the top rod passes through the through hole upward and is arranged below a partition ring, the partition ring is arranged below the rubber sleeve, and the inner hole of the partition ring is in clearance fit with the outer heat insulation sleeve.

[0008] The center tube extends outward at the position of the top rod part to a support shaft, the support shaft is placed on the lower part of the inner heat insulation sleeve, the support shaft is provided with an upper hole and a lower hole at the position of the top rod part, the upper hole is larger than the lower hole, the top rod passes through the upper hole and the lower hole, an expansion tube is installed in the upper hole, the expansion tube is made of polyethylene material, the lower part of the expansion tube is provided with a locking sleeve, the locking sleeve falls on the bottom of the upper hole, the upper part of the support shaft is connected with a gland through a bolt, the gland is pressed on the upper part of the expansion tube, the locking sleeve is made of elastic metal, the upper part of the locking sleeve is a conical surface which is reduced upward, the locking sleeve is provided with six evenly distributed slits in the circumferential direction, the inner hole of the locking sleeve is processed into a continuous one-way tooth ring, the direction of the one-way tooth ring is that when the inner hole of the locking sleeve is reduced and wrapped on the top rod, the one-way tooth ring enables the top rod to only move upward.

[0009] The center tube is provided with a plurality of heat conduction grooves at the position of the support shaft, and the heat conduction grooves extend to the position near the upper hole.

[0010] The outer edge of the lower cooling disc is provided with an annular groove, and the upper and lower end faces of the lower cooling disc are provided with annular corrugated structures.

[0011] In use, the upper and lower high-efficiency heat extraction packers are used at the same time, wherein the rubber sleeve of the upper high-efficiency heat extraction packer is installed above the piston, and the rubber sleeve of the lower high-efficiency heat extraction packer is installed below the piston.

[0012] The lower part of the locking sleeve is provided with a stepped hole, and the slits are opened downward to the position of the stepped hole.

[0013] The outer edge and the inner hole of the piston are provided with two ring grooves, high-temperature-resistant fillers are inserted into the ring grooves, the bottom of the fillers is provided with a partition plate, and the piston is provided with a pressure channel which communicates the two ring grooves and the pressure surface of the piston.

[0014] A plurality of gaskets are arranged between the gland and the expansion tube.

[0015] The beneficial effects of the present application are as follows: 1. The upper cooler and the lower cooler are arranged above and below the rubber sleeve, and the heat pipe has the characteristics of heat transfer, the heat pipe mainly relies on the vapor-liquid phase change of the working liquid for heat transfer, the thermal resistance is very small, and therefore the heat pipe has very high heat conduction capacity, the lower cooler transmits the heat of the steam at the lower part of the rubber sleeve to the upper cooler, and the upper cooler radiates the heat away, so as to reduce the external environment temperature of the rubber sleeve;

[0016] 2. Due to the annular corrugated structures of the upper and lower end faces of the lower cooling disc, the outer circle of the lower cooling disc expands when heated, the elasticity of the outer circle of the lower cooling disc is attached to the inner wall of the sleeve, and the steam can be directly blocked on the lower side of the rubber sleeve, at the same time, the lower cooling disc directly contacts the sleeve, and can directly exchange heat with the sleeve below the rubber sleeve, that is, the temperature of the sleeve in contact with the rubber sleeve is reduced, the temperature of the rubber sleeve is further reduced, the sealing performance and service life of the rubber sleeve are improved, and the annular groove of the outer circle of the lower cooling disc forms an annular space between the lower cooling disc and the sleeve, which is beneficial to heat insulation and elastic connection.

[0017] 3. The locking mechanism consists of a support shaft, an expansion tube, and a locking sleeve, which can lock the top rod at a set temperature, allowing the rubber sleeve to be stably sealed with the sleeve within a certain temperature range. At this time, the seal of the rubber sleeve is not affected by changes in the injected steam pressure. At the same time, the unsealing temperature is high, the speed is fast, and the operation efficiency is high. Attached Figure Description

[0018] Appendix Figure 1 This is a schematic diagram of the structure of the present invention;

[0019] Appendix Figure 2 It is attached Figure 1 Enlarged view of point A;

[0020] Appendix Figure 3 It is attached Figure 1 Enlarged view of point B;

[0021] Appendix Figure 4 It is attached Figure 1 Enlarged view of point C;

[0022] Appendix Figure 5 This is a schematic diagram of the central tube in this invention;

[0023] Appendix Figure 6 This is a schematic diagram showing the connection between the upper cooler and the lower cooler in this invention;

[0024] Appendix Figure 7 This is a schematic diagram of the locking sleeve in this invention;

[0025] Appendix Figure 8 This is a perspective view of the locking sleeve in this invention;

[0026] Appendix Figure 9 This is an installation diagram of the present invention.

[0027] In the diagram, 1-upper connector, 2-lower connector, 201-cylinder liner, 3-center tube, 301-support shaft, 302-upper section hole, 303-lower section hole, 304-heat conduction groove, 305-liquid inlet hole, 4-piston, 401-packing, 402-partition plate, 403-pressure channel, 5-push rod, 6-rubber sleeve, 7-gasket, 8-inner heat insulation sleeve, 9-upper cooler, 901-upper cooling plate, 902-outer contact sleeve. 10-Outer heat insulation sleeve, 11-Spacer ring, 12-Lower cooler, 1201-Lower cooling plate, 1202-Inner contact sleeve, 1203-Through hole, 13-Nut, 14-Capillary material, 15-Glander cap, 16-Expansion tube, 17-Locking sleeve, 1701-Conical surface, 1702-Slit, 1703-One-way toothed ring, 1704-Stepped hole, 18-Sleeve, 19-Annular groove, 20-Annular corrugation. Detailed Implementation

[0028] As Figures 1-9 A high efficient thermal recovery packer, comprising an upper joint 1 and a lower joint 2, the upper joint 1 is threadedly connected with a central pipe 3, the lower part of the central pipe 3 is threadedly connected with the lower joint 2, the outer edge of the lower joint 2 extends upwardly a cylinder sleeve 201, a piston 4 is arranged between the cylinder sleeve 201 and the central pipe 3, the piston 4 is connected with the cylinder sleeve 201 and the central pipe 3 through a sealing assembly clearance fit, the central pipe 3 is provided with a liquid inlet hole 305 below the sealing assembly of the piston 4;

[0029] The outer side of the central pipe 3 is sleeved with an inner heat insulation sleeve 8, the inner heat insulation sleeve 8 is arranged on the lower part of the upper joint 1, the upper part of the inner heat insulation sleeve 8 is provided with a flange for positioning, the outer side of the inner heat insulation sleeve 8 is sleeved with an upper cooler 9 and a lower cooler 12, the upper cooler 9 is provided with two upper cooling discs 901, the lower cooler 12 is provided with two lower cooling discs 1201, the upper cooler 9 is provided with an outer contact sleeve 902, the lower cooler 12 is provided with an inner contact sleeve 1202, the outer contact sleeve 902 and the inner contact sleeve 1202 are inserted together, the lower part of the inner heat insulation sleeve 8 is threadedly connected with two nuts 13, the two nuts 13 are arranged at the lower part of the lower cooling disc 1201, the outer side of the outer contact sleeve 902 and the inner contact sleeve 1202 is sleeved with an outer heat insulation sleeve 10, the outer side of the outer heat insulation sleeve 10 is sleeved with a rubber tube 6, the upper part of the outer heat insulation sleeve 10 is provided with a flange clamped between the rubber tube 6 and the upper cooling disc 901;

[0030] The upper cooler 9 and the lower cooler 12 are both heat pipe structures: the upper cooler 9 and the lower cooler 12 are both closed cavity structures, the inner wall of the cavity is bonded with a capillary material 14, the cavity is filled with a working liquid, and the air pressure in the cavity is in a negative pressure state;

[0031] The upper part of the piston 4 is fixedly connected with a top rod 5, the number of the top rod 5 is four and is uniformly arranged in a circle, the lower cooling disc 1201 is provided with a through hole 1203 at the position of the top rod 5, the top rod 5 passes upwardly through the through hole 1203 and is arranged below a partition ring 11, the partition ring 11 is arranged below the rubber tube 6, and the inner hole of the partition ring 11 is clearance fit with the outer heat insulation sleeve 10.

[0032] The center tube 3 extends outward at the position of the ejector rod 5 by a supporting shaft 301, the supporting shaft 301 is located at the lower part of the inner heat insulation sleeve 8, the supporting shaft 301 is provided with an upper hole 302 and a lower hole 303 at the position of the ejector rod 5, the upper hole 302 is larger than the lower hole 303, the ejector rod 5 passes through the upper hole 302 and the lower hole 303, the expansion tube 16 is installed in the upper hole 302, the expansion tube 16 is made of polyethylene material, the expansion tube 16 is provided with a locking sleeve 17 at the lower part, the locking sleeve 17 is located at the bottom of the upper hole 302, the upper part of the supporting shaft 301 is connected with the gland 15 through bolts, the gland 15 is pressed on the upper part of the expansion tube 16, the locking sleeve 17 is made of elastic metal, the upper part of the locking sleeve 17 is a conical surface 1701 which is reduced upward, the locking sleeve 17 is provided with six evenly distributed slits 1702 in the circumferential direction, the inner hole of the locking sleeve 17 is processed into a continuous one-way tooth ring 1703, the direction of the one-way tooth ring 1703 is that when the inner hole of the locking sleeve 17 is reduced and wrapped on the ejector rod 5, the one-way tooth ring 1703 makes the ejector rod 5 only move upward;

[0033] The center tube 3 is provided with a plurality of heat conduction grooves 304 at the position of the supporting shaft 301, the heat conduction grooves 304 extend to the position near the upper hole 302, so as to improve the temperature at the position of the supporting shaft 301.

[0034] The supporting shaft 301, the expansion tube 16 and the locking sleeve 17 form a locking mechanism, which can lock the ejector rod 5 at a set temperature, so that the rubber cylinder 6 can stably seal with the sleeve 18 in a certain temperature range, at this time, the sealing of the rubber cylinder 6 is not affected by the change of the injection steam pressure, and the unsealing temperature is high.

[0035] The lower cooling disc 1201 is provided with an annular groove 19 at the outer edge, and the upper and lower end faces of the lower cooling disc 1201 are provided with annular corrugated structures 20, and the upper cooling disc 901 has the same structure.

[0036] The upper cooler 9 and the lower cooler 12 are arranged above and below the rubber cylinder 6, the heat pipe is used to transfer heat, the lower cooler 12 transfers the heat of the steam at the lower part of the rubber cylinder 6 to the upper cooler 9, and the upper cooler 9 radiates the heat, so as to reduce the external environment temperature of the rubber cylinder 6, due to the annular corrugated structures 20 at the upper and lower end faces of the lower cooling disc 1201, the outer circle of the lower cooling disc 1201 expands when heated, and the outer circle of the lower cooling disc 1201 is elastically attached to the inner wall of the sleeve 18, so as to directly block the steam at the lower side of the rubber cylinder 6, and the lower cooling disc 1201 directly contacts with the sleeve 18, so as to exchange heat with the sleeve 18 below the rubber cylinder 6, that is, the temperature of the sleeve 18 contacting with the rubber cylinder 6 is reduced, the temperature of the rubber cylinder 6 is further reduced, the sealing performance and service life of the rubber cylinder 6 are improved, the annular groove 19 at the outer circle of the lower cooling disc 1201 forms an annular space between the lower cooling disc 1201 and the sleeve 18, which is beneficial to heat insulation and elastic connection.

[0037] In use, the upper and lower efficient thermal recovery packers are used simultaneously, wherein the upper efficient thermal recovery packer rubber sleeve 6 is installed above the piston 4, and the lower efficient thermal recovery packer rubber sleeve 6 is installed below the piston 4, so that the expansion tube 16 is in a steam heating position, and the tasks of locking the top rod 5 and the rubber sleeve 6 are completed.

[0038] The lower part of the locking sleeve 17 is provided with a stepped hole 1704, the slits 1702 are opened to the position of the stepped hole 1704, and the inner hole of the locking sleeve 17 is more uniform when it is contracted.

[0039] The outer edge and the inner hole of the piston 4 are provided with two ring grooves, the ring grooves are filled with the packing 401, the bottom of the packing 401 is provided with a partition plate 402, the piston 4 is provided with a pressure channel 403, the pressure channel 403 communicates the two ring grooves and the pressure surface of the piston 4, the steam pressure can act on the partition plate 402 through the pressure channel 403, the partition plate 402 compresses the packing 401 outward, and the sealing effect is better.

[0040] A plurality of gaskets 7 are arranged between the gland 15 and the expansion tube 16, the number of the gaskets 7 can be changed according to needs, the length of the expansion tube 16 is changed, and thus the expansion tube 16 is expanded at a certain temperature range, and the locking sleeve 17 is contracted to lock the top rod 5.

[0041] The compression spring is arranged between the piston 4 and the support shaft 301, when the temperature drops to a set unsealing temperature, the locking sleeve 17 releases the top rod 5, and the piston 4 can be lowered under the action of the compression spring.

[0042] After the efficient thermal recovery packer is lowered into the well, high-pressure steam is introduced into the pipe string, the high-pressure steam drives the piston 4 and the top rod 5 to rise, drives the spacer ring 11 to rise, and the rubber sleeve 6 is compressed and expanded to be seated on the inner wall of the casing 18, when the temperature in the well reaches a set value or above, the expansion tube 16 is expanded and lengthened, the locking sleeve 17 is compressed and locked, the locking sleeve 17 locks the top rod 5 and cannot be lowered, and thus the sealing of the rubber sleeve 6 is fixed, at the set temperature or above, the change of the temperature cannot cause the change of the sealing performance of the rubber sleeve 6, the set temperature of the application is 260°C, that is, when the temperature of the efficient thermal recovery packer reaches 260°C or above after the steam is injected, the rubber sleeve 6 is locked and sealed, when the rubber sleeve 6 leaks, the steam pressure can be increased, the piston 4 and the top rod 5 continue to rise, the expansion degree of the rubber sleeve 6 is increased, and the sealing effect is improved, when unsealing, the temperature is lower than 260°C, the expansion tube 16 is contracted, the locking sleeve 17 releases the top rod 5, the piston 4 is lowered under the action of the compression spring and the self weight, the rubber sleeve 6 is retracted and unsealed, and the unsealing is rapid.

Claims

1. A high-efficiency thermal recovery packer comprising an upper joint (1) and a lower joint (2), characterized in that: The upper joint (1) is threadedly connected with the central pipe (3), the lower joint (2) is threadedly connected with the lower part of the central pipe (3), the outer edge of the lower joint (2) extends upwardly to form a cylinder sleeve (201), the piston (4) is arranged between the cylinder sleeve (201) and the central pipe (3), the piston (4) is connected with the cylinder sleeve (201) and the central pipe (3) through a sealing assembly gap fit, and the central pipe (3) is provided with a liquid inlet hole (305) below the sealing assembly of the piston (4); The inner heat insulation sleeve (8) is sleeved outside the central pipe (3), the inner heat insulation sleeve (8) is arranged on the lower part of the upper joint (1), the upper part of the inner heat insulation sleeve (8) is provided with a flange for positioning, the outer side of the inner heat insulation sleeve (8) is sleeved with the upper cooler (9) and the lower cooler (12), the upper cooler (9) is provided with two upper cooling discs (901), the lower cooler (12) is provided with two lower cooling discs (1201), the upper cooler (9) is provided with an outer contact sleeve (902), the lower cooler (12) is provided with an inner contact sleeve (1202), the outer contact sleeve (902) and the inner contact sleeve (1202) are inserted together, the lower part of the inner heat insulation sleeve (8) is threadedly connected with two nuts (13), the two nuts (13) are arranged below the lower cooling disc (1201), the outer side of the outer contact sleeve (902) and the inner contact sleeve (1202) is sleeved with the outer heat insulation sleeve (10), the outer side of the outer heat insulation sleeve (10) is sleeved with the rubber tube (6), the upper part of the outer heat insulation sleeve (10) is provided with a flange which is clamped between the rubber tube (6) and the upper cooling disc (901); The upper cooler (9) and the lower cooler (12) are both heat pipe structures, the upper cooler (9) and the lower cooler (12) are both closed cavity structures, the inner wall of the cavity is bonded with capillary material (14), the cavity is filled with working liquid, and the air pressure in the cavity is in a negative pressure state; The upper part of the piston (4) is fixedly connected with the top rod (5), the number of the top rod (5) is four and they are uniformly arranged in a circle, the lower cooling disc (1201) is provided with a through hole (1203) at the position of the top rod (5), the top rod (5) passes upwardly through the through hole (1203) and is arranged below the partition ring (11), the partition ring (11) is arranged below the rubber tube (6), and the inner hole of the partition ring (11) is gap-fitted with the outer heat insulation sleeve (10).

2. The high efficiency thermal production packer of claim 1, wherein: The center tube (3) extends outward at the position of the ejector rod (5) by a support shaft (301), the support shaft (301) is located at the lower part of the inner heat insulation sleeve (8), the support shaft (301) is provided with an upper hole (302) and a lower hole (303) at the position of the ejector rod (5), the upper hole (302) is larger than the lower hole (303), the ejector rod (5) passes through the upper hole (302) and the lower hole (303), the expansion tube (16) is installed in the upper hole (302), the expansion tube (16) is made of polyethylene material, the expansion tube (16) is provided with a locking sleeve (17) at the lower part, the locking sleeve (17) falls on the bottom of the upper hole (302), the upper part of the support shaft (301) is connected with the gland (15) by bolts, the gland (15) is pressed on the upper part of the expansion tube (16), the locking sleeve (17) is made of elastic metal, the upper part of the locking sleeve (17) is a conical surface (1701) which is reduced upward, the locking sleeve (17) is provided with six evenly distributed slits (1702) in the circumferential direction, the inner hole of the locking sleeve (17) is processed into a continuous one-way tooth ring (1703), the direction of the one-way tooth ring (1703) is that when the inner hole of the locking sleeve (17) is reduced and wrapped on the ejector rod (5), the one-way tooth ring (1703) makes the ejector rod (5) only move upward; The center tube (3) is provided with a plurality of heat conduction grooves (304) at the position of the support shaft (301), the heat conduction grooves (304) extend to the position near the upper hole (302).

3. The high efficiency thermal production packer of claim 1, wherein: The outer edge of the lower cooling disc (1201) is provided with an annular groove (19), the upper and lower end faces of the lower cooling disc (1201) are provided with annular corrugated structures (20), and the upper cooling disc (901) has the same structure.

4. The high efficiency thermal production packer of claim 1, wherein: In use, the upper and lower high-efficiency heat production packers are used at the same time, the rubber sleeve (6) of the upper high-efficiency heat production packer is installed above the piston (4), and the rubber sleeve (6) of the lower high-efficiency heat production packer is installed below the piston (4).

5. The high efficiency thermal production packer of claim 2, wherein: The lower part of the locking sleeve (17) is provided with a stepped hole (1704), and the slits (1702) are opened downward to the position of the stepped hole (1704).

6. The high efficiency thermal production packer of claim 1, wherein: The outer edge and the inner hole of the piston (4) are provided with two ring grooves, the ring grooves are filled with the packing (401), the bottom of the packing (401) is provided with a partition plate (402), the piston (4) is provided with a pressure channel (403), and the pressure channel (403) communicates the two ring grooves and the pressure receiving surface of the piston (4).

7. The high efficiency thermal production packer of claim 2, wherein: A plurality of gaskets (7) are arranged between the gland (15) and the expansion tube (16).

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