Constant-set packer force heat-sensitive long rubber cylinder steam injection pipe column

Abstract

The application discloses a constant setting force heat-sensitive long rubber cylinder steam injection pipe column and belongs to the technical field of oil production technology. The constant setting force heat-sensitive long rubber cylinder steam injection pipe column comprises a sleeve, a hydraulic release telescopic pipe assembly, a heat-sensitive packer assembly, an anchoring packer assembly and a ball seat assembly which are sequentially communicated through the oil pipe and are arranged in the sleeve. A ball is put into the oil pipe, the ball is adapted to be matched with the ball seat assembly and seals the oil pipe at the ball seat assembly, high-pressure fluid is injected into the oil pipe, the anchoring packer assembly is elongated towards the direction of the sleeve and is anchored on the inner wall of the sleeve, the hydraulic release telescopic pipe assembly is elongated along the axial direction, so that the upper joint assembly and the lower joint assembly in the heat-sensitive packer assembly realize relative movement, steam is injected into the oil pipe, the heat-sensitive packer assembly is expanded towards the inner wall of the sleeve after being heated and seals and blocks the sleeve. The steam injection pipe column has the advantage that the setting pressure of the heat-sensitive packer assembly on the sleeve is effectively reduced.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of oil extraction, and particularly relates to a constant setting force heat-sensitive long rubber sleeve steam injection pipe column. BACKGROUND

[0002] The setting force of the packer in the existing steam injection pipe column is uncontrollable. In order to ensure the steam injection sealing property in the downhole high-temperature environment, the setting force is often very large. Under the long-term high-temperature environment in the downhole, the casing at the packer setting position is prone to deformation due to the long-term influence of the radial pressure of the packer. Long-term stress can easily cause casing damage and steam injection pipe column sealing failure and other problems, causing irreversible damage to the casing, and greatly reducing the service life of the steam injection pipe column. SUMMARY

[0003] The application aims to at least solve the technical problem that the casing at the packer setting position is prone to deformation or damage due to the long-term influence of the radial pressure of the packer, thereby affecting the sealing property of the steam injection pipe column. Therefore, the application provides a constant setting force heat-sensitive long rubber sleeve steam injection pipe column.

[0004] In a first aspect, the application provides a constant setting force heat-sensitive long rubber sleeve steam injection pipe column, comprising: a casing; and a hydraulic release telescopic pipe assembly, a heat-sensitive packer assembly, an anchoring packer assembly and a ball seat assembly arranged in the casing and sequentially communicated through an oil pipe. By injecting a ball into the oil pipe, the ball is adapted to be matched with the ball seat assembly and seal the oil pipe at the ball seat assembly. By injecting high-pressure fluid into the oil pipe, the anchoring packer assembly is elongated towards the direction of the casing and anchored on the inner wall of the casing. The hydraulic release telescopic pipe assembly is elongated in the axial direction to enable the upper joint assembly and the lower joint assembly in the heat-sensitive packer assembly to move relatively. Steam is injected into the oil pipe. After being heated, the heat-sensitive packer assembly expands towards the inner wall of the casing and seals and blocks the casing.

[0005] The heat-sensitive packer assembly comprises the upper joint assembly and the lower joint assembly. The upper joint assembly and the lower joint assembly are detachably connected.

[0006] The upper joint assembly comprises an outer central pipe and a heat-sensitive rubber sleeve sleeved on the outer central pipe. A heat-sensitive cavity is formed on the heat-sensitive rubber sleeve, and a heat-sensitive substance is contained in the heat-sensitive cavity.

[0007] The upper joint assembly further comprises an upper connector and an upper joint, one end of the upper joint is connected with the oil pipe, the other end is connected with the first end of the upper connector, and the second end of the upper connector is detachably connected with the outer central pipe.

[0008] The lower joint assembly comprises an inner central pipe, and the outer central pipe is sleeved on the inner central pipe and connected as a whole through a pin.

[0009] An annular cavity with an opening facing the inner central pipe is formed on the outer central pipe, and the annular cavity and the outer wall of the inner central pipe are jointly configured as a buffer chamber.

[0010] A through hole is formed on the outer wall of the inner central pipe, and the through hole is in communication with the buffer chamber.

[0011] The lower joint assembly further comprises a lower connector, and the lower connector is detachably connected with the inner central pipe.

[0012] The lower joint assembly further comprises a lower joint which is partially sleeved on the lower connector and is detachably connected with the lower connector.

[0013] The lower joint assembly further comprises an outer sleeve ring and a deblocking needle seat which is sleeved on the lower connector, one end of the outer sleeve ring is sealingly connected with the heat-sensitive rubber cylinder, and the other end of the outer sleeve ring is connected as a whole with the deblocking needle seat through a deblocking pin.

[0014] The lower joint assembly further comprises a deblocking needle which is arranged on the deblocking needle seat and extends towards the side end face of one end of the heat-sensitive rubber cylinder.

[0015] The anchoring packer assembly comprises an anchoring packer body which is in communication with the oil pipe, and an anchoring claw which is arranged on the anchoring packer body and extends towards the inner wall of the casing.

[0016] The constant setting force heat-sensitive long rubber cylinder steam injection pipe column further comprises a ball basket and a steam injection valve, the ball basket is arranged below the ball seat assembly and is adapted to catch the ball which is put into the oil pipe, and the steam injection valve is arranged on the oil pipe which connects the ball basket and the ball seat assembly.

[0017] Compared with the prior art, the constant setting force heat-sensitive long rubber cylinder steam injection pipe column has the following advantages:

[0018] After setting the sealing gas, the constant-setting-force thermosensitive long rubber sleeve steam injection string of this application is inserted, and a ball is inserted into the oil pipe. The ball will be locked at the opening of the ball seat assembly, at which time the ball seat assembly is in a sealed state. By injecting high-pressure fluid into the oil pipe, the constant-setting-force thermosensitive long rubber sleeve steam injection string begins to pressurize. When the pressure in the constant-setting-force thermosensitive long rubber sleeve steam injection string reaches a certain level, the anchoring packer assembly extends towards the casing and anchors to the inner wall of the casing. The hydraulic release telescopic tube assembly extends axially, so that the upper connector assembly and the lower connector assembly in the thermosensitive packer assembly achieve relative movement. Steam is injected into the oil pipe. After being heated, the thermosensitive packer assembly will expand towards the inner wall of the casing and seal the casing. It can be seen that this application... The self-weight of the tubing between the thermal packer assembly and the hydraulic release telescopic tube assembly balances the setting force of the thermal packer assembly, allowing it to maintain a constant setting force throughout operation regardless of the steam injection temperature. Furthermore, the thermal packer assembly in this application employs a long rubber sleeve design, significantly increasing the contact area between the thermal packer sleeve and the bushing. This effectively reduces the setting pressure of the thermal packer assembly on the bushing, further minimizing damage to the bushing. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 A schematic diagram of the overall structure of the constant-seating-force thermosensitive long rubber tube steam injection pipe column according to an embodiment of this application is shown;

[0021] Figure 2 for Figure 1 A schematic diagram of the overall structure of the thermal packer assembly.

[0022] Reference numerals: 1: Sleeve; 2: Oil pipe; 3: Hydraulic release telescopic tube assembly; 4: Thermosensitive packer assembly; 41: Upper connector assembly; 411: Outer central tube; 412: Thermosensitive rubber sleeve; 413: Upper connector; 414: Upper connector; 421a: Thermosensitive cavity; 42: Lower connector assembly; 421: Inner central tube; 421a: Through hole; 422: Pin; 423: Lower connector; 424: Lower connector; 425: Outer ring; 426: Release needle seat; 427: Release needle; 428: Buffer chamber; 429: Release needle; 5: Anchor packer assembly; 51: Anchor packer body; 52: Anchor claw; 6: Ball seat assembly; 7: Ball. DETAILED DESCRIPTION

[0023] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all the other embodiments obtained by a person of ordinary skill in the art without creative work under the premise that the embodiments in the present application are within the scope of protection of the present application.

[0024] It should be noted that all the directionality indications in the embodiments of the present application are only used to explain the relative position relationship, movement condition and the like between components in a certain posture, and if the certain posture changes, the directionality indications also change accordingly.

[0025] In the present application, unless otherwise explicitly specified and limited, the terms “connection”, “fixation” and the like should be understood in a broad sense, for example, “fixation” can be fixed connection, or detachable connection, or integral; can be mechanical connection, or electrical connection; can be direct connection, or indirect connection through an intermediate medium; can be the internal communication of two elements or the interaction relationship between two elements, unless otherwise explicitly limited. For a person of ordinary skill in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0026] In addition, the description such as “first”, “second” and the like in the present application is only for the purpose of description, and cannot be understood as indicating or implying the relative importance of the indicated technical features or implicitly indicating the number of the indicated technical features. Therefore, the features limited by “first”, “second” can explicitly or implicitly include at least one of the features. In addition, the technical solutions of each embodiment can be combined with each other, but it must be based on the fact that a person of ordinary skill in the art can realize it, and when the combination of technical solutions appears contradictory or unachievable, it should be considered that the combination of technical solutions does not exist, and is also not within the scope of protection claimed by the present application.

[0027] In the related art, the setting force of the packer in the existing steam injection pipe column is uncontrollable, in order to ensure the steam injection sealing property in the downhole high temperature environment, the setting force is often large, under the long-term high temperature environment in the downhole, the casing at the packer setting position is easy to deform due to the long-term influence of the radial pressure of the packer, long-term stress is easy to cause casing damage and steam injection pipe column sealing failure and other problems, which causes irreversible damage to the casing, and also greatly reduces the service life of the steam injection pipe column. The embodiments of the present application provide a constant setting force heat-sensitive long rubber sleeve steam injection pipe column, which can at least solve the problem that the casing at the packer setting position is easy to deform due to the long-term influence of the radial pressure of the packer, long-term stress is easy to cause casing damage and steam injection pipe column sealing failure and other problems, which causes irreversible damage to the casing, and also greatly reduces the service life of the steam injection pipe column.

[0028] The present application will be described below in conjunction with the accompanying drawings Figures 1 to 2 and with reference to specific embodiments:

[0029] The embodiments of the present application provide a constant setting force heat-sensitive long rubber sleeve steam injection pipe column, which includes a casing 1, a tubing 2, a hydraulic release telescopic pipe assembly 3, a heat-sensitive packer assembly 4, an anchor packer assembly 5, a ball seat assembly 6, a ball 7, a ball basket 8 and a steam injection valve 9.

[0030] In the embodiments of the present application, the hydraulic release telescopic pipe assembly 3, the thermal packer assembly 4, the anchoring packer assembly 5 and the ball seat assembly 6 are all arranged in the casing 1 and sequentially communicated through the oil pipe 2, wherein by putting the ball 7 into the oil pipe 2, the ball 7 is adapted to be matched with the ball seat assembly 6 and seal the oil pipe 2 at the ball seat assembly 6, by injecting high-pressure fluid into the oil pipe 2, the anchoring packer assembly 5 is elongated towards the casing 1 and anchored on the inner wall of the casing 1, the hydraulic release telescopic pipe assembly 3 is elongated in the axial direction to enable the relative movement between the upper joint assembly 41 and the lower joint assembly 42 of the thermal packer assembly 4, and by injecting steam into the oil pipe 2, the thermal packer assembly 4 is expanded towards the inner wall of the casing 1 after being heated and seals the casing 1. Specifically, after setting, the constant setting force thermal long rubber sleeve steam injection pipe column of the present application is run in, at this time the ball seat assembly 6 is in the open state and there is no ball at the ball seat assembly 6, the ball 7 is put into the oil pipe 2, the ball 7 is clamped at the opening of the ball seat assembly 6, at this time the ball seat assembly 6 is in the sealed state. By injecting high-pressure fluid into the oil pipe 2 (for example, injecting clean water into the oil pipe 2 of the constant setting force thermal long rubber sleeve steam injection pipe column), the pressure in the constant setting force thermal long rubber sleeve steam injection pipe column starts to rise, when the pressure in the constant setting force thermal long rubber sleeve steam injection pipe column reaches a certain degree, the anchoring packer assembly 5 is elongated towards the casing 1 and anchored on the inner wall of the casing 1, the hydraulic release telescopic pipe assembly 3 is elongated in the axial direction to enable the relative movement between the upper joint assembly 41 and the lower joint assembly 42 of the thermal packer assembly 4, and by injecting steam into the oil pipe 2, the thermal packer assembly 4 is expanded towards the inner wall of the casing 1 after being heated and seals the casing 1. It can be seen that the pipe column self-weight between the thermal packer assembly 4 and the hydraulic release telescopic pipe assembly 3 of the present application is used to balance the setting force of the thermal packer assembly 4, so that the thermal packer assembly 4 can not be affected by the steam injection temperature and always maintain a constant setting force during the working process. At the same time, the thermal rubber sleeve 42 in the thermal packer assembly 4 of the present application adopts a long rubber sleeve design, thereby greatly increasing the contact area between the thermal rubber sleeve 412 in the thermal packer assembly 4 and the casing 1, effectively reducing the setting pressure of the thermal packer assembly 4 on the casing 1, and further reducing the damage of the thermal packer assembly 4 to the casing 1.

[0031] As shown in Figure 2 some embodiments, the thermal packer assembly 4 includes the upper joint assembly 41 and the lower joint assembly 42, and the upper joint assembly 41 is detachably connected with the lower joint assembly 42. Specifically, in the working state, the thermal packer assembly 4 is located underground, the upper joint assembly 41 is arranged above the lower joint assembly 42, and the upper joint assembly 41 and the lower joint assembly 42 are connected as a whole by means of buckling, bolts or threaded connection.

[0032] As shown in Figure 2 some embodiments of the present application, the upper joint assembly 41 comprises an outer central tube 411 and a heat-sensitive rubber sleeve 412 sleeved on the outer central tube 411, wherein a heat-sensitive cavity 412a is formed on the heat-sensitive rubber sleeve 412, and a heat-sensitive substance is contained in the heat-sensitive cavity 412a. Specifically, by sleeving the heat-sensitive rubber sleeve 412 on the outer central tube 411 and containing the heat-sensitive substance in the heat-sensitive rubber sleeve 412, when steam is injected into the oil pipe 1, at this time, the heat-sensitive substance in the heat-sensitive rubber sleeve 412 is heated and expands, prompting the heat-sensitive rubber sleeve 412 to move towards the inner wall of the casing 1, thereby sealing the upper and lower spaces in the casing 1 and achieving the setting of the casing 1. At this time, the heat-sensitive rubber sleeve 412 is subjected to the pressure of the upper joint assembly 41 and the lower end pipe string of the hydraulic release telescopic pipe assembly 3, and when the pressure of the heat-sensitive rubber sleeve 412 is too large, the heat-sensitive rubber sleeve 412 can push up the upper joint assembly 41 and the hydraulic release telescopic pipe assembly 3, so as to ensure that the pressure of the heat-sensitive rubber sleeve 412 is balanced with the weight of the upper joint assembly 41 and the hydraulic release telescopic pipe assembly 3, at this time, the heat-sensitive rubber sleeve 412 is axially elongated, but the setting force of the heat-sensitive rubber sleeve 412 remains constant.

[0033] As shown in Figure 2 some embodiments of the present application, the upper joint assembly 41 further comprises an upper connector 413 and an upper joint 414, wherein one end of the upper joint 414 is connected with the oil pipe 2, the other end is connected with the first end of the upper connector 413, and the second end of the upper connector 413 is detachably connected with the outer central tube 411. Specifically, one end of the upper joint 414 is detachably connected (threaded connection, bolt connection or buckle connection) with the oil pipe 2, the other end is detachably connected (threaded connection, bolt connection or buckle connection) with the upper connector 413, and the second end of the upper connector 413 is detachably connected with the outer central tube 411, so as to facilitate the quick installation and disassembly between the upper joint 414, the upper connector 413 and the outer central tube 411.

[0034] As shown in Figure 2 some embodiments of the present application, the lower joint assembly 42 comprises an inner central tube 421, and the outer central tube 411 is sleeved on the inner central tube 421 and connected as a whole through a pin 422. Specifically, the outer central tube 411 is sleeved on the inner central tube 421 and connected as a whole through the pin 422, so as to achieve firm connection between the outer central tube 411 and the inner central tube 421. Specifically, the pin 422 penetrates the outer wall of the outer central tube 411 and the outer wall of the inner central tube 421 in sequence, and by tightening the pin 422, the fixed connection between the outer central tube 411 and the inner central tube 421 can be achieved.

[0035] AsFigure 2 As shown, in some embodiments of this application, an annular cavity with an opening facing the inner central tube 411 is constructed on the outer central tube 411, wherein the annular cavity and the outer wall of the inner central tube 421 together constitute a buffer chamber 428. It should be noted that the buffer chamber 428 is suitable for partial inflow of high-pressure fluid.

[0036] like Figure 2 As shown, in some embodiments of this application, a through hole 421a is formed on the outer wall of the inner central tube 421, and the through hole 421a is connected to the buffer chamber 428. Specifically, before setting, high-pressure fluid is injected into the oil pipe 2. The high-pressure fluid flows through the oil pipe 2, through the inner central pipe 421, and through the through hole 421a on the inner central pipe 421 into the buffer chamber 428. As the amount of high-pressure fluid flowing into the buffer chamber 428 gradually increases, the pressure in the buffer chamber 428 gradually increases, thereby driving the inner central pipe 421 and the outer central pipe 411 to move relative to each other. That is, under normal circumstances, since the inner central pipe 421 and the outer central pipe 411 are fixedly connected as one unit by the pin 422, it is ensured that there is no relative movement between the inner central pipe 421 and the outer central pipe 411. However, when the shear force between the inner central pipe 421 and the outer central pipe 411 reaches a certain level, the pin 422 will be sheared, thereby realizing the relative movement between the inner central pipe 421 and the outer central pipe 411.

[0037] like Figure 2 As shown, in some embodiments of this application, the lower connector assembly 42 further includes a lower connector 423, which is detachably connected to the inner central tube 421. Specifically, the lower connector 423 and the inner central tube 421 can be connected as one unit by means of threaded connection or snap-fit ​​connection, etc.

[0038] like Figure 2 As shown, in some embodiments of this application, the lower connector assembly 42 further includes a lower connector 424 that is partially sleeved on the lower connector 423 and detachably connected to the lower connector 423. Specifically, the lower connector 424 can be connected to the lower connector 423 as a whole through a connection method such as threaded connection, bolt connection, or snap-fit ​​connection.

[0039] like Figure 2As shown, in some embodiments of this application, the lower connector assembly 42 further includes an outer ring 425 and a release pin seat 426 sleeved on the lower connector 423. One end of the outer ring 425 is sealed and connected to the heat-sensitive adhesive cartridge 412, and the other end of the outer ring 425 is integrally connected to the release pin seat 426 via a release pin 427. Specifically, the release pin seat 426 is sleeved on the lower connector 423, one end of the outer ring 425 is sealed and connected to the heat-sensitive adhesive cartridge 412, and the other end is integrally connected to the release pin seat 426 via a release pin 427. Specifically, during unsealing, the oil pipe 2 is lowered. At this time, the lower connector assembly 42 in the thermal packer assembly 4 is fixed by the lower anchoring packer assembly 5. When the steam injection string of this application is lowered, the upper connector assembly 41 in the thermal packer assembly 4 pushes the thermal rubber sleeve 412 downward. When the pressure reaches a certain level, the thermal rubber sleeve 412 acts on the downward pressure on the outer ring 425. Figure 2 When the force applied (horizontally to the right) exceeds the shearing force of the unsealing pin 427, the unsealing pin 427 is sheared off. Simultaneously, the unsealing needle seat 426 is knocked off, and the unsealing needle 429, as shown below, contacts and punctures the thermosensitive adhesive sleeve 412, thereby achieving unsealing. After the thermosensitive packer assembly 4 is unsealed, the steam injection string of this application is lifted. When the lifting force reaches a certain level, the unsealing pin (not shown in the figure) in the anchor packer assembly 5 is sheared off, and the anchoring claw in the anchor packer assembly 5 retracts towards the center in the direction away from the inner wall of the sleeve 1. At this time, the steam injection string of this application is no longer anchored to the sleeve 1. The tool can be removed by lifting the steam injection string of this application from top to bottom.

[0040] like Figure 2 As shown, in some embodiments of this application, the lower connector assembly 42 further includes an unsealing needle 429 disposed on the unsealing needle seat 426 and extending toward the side end face of one end of the thermosensitive adhesive tube 412. Specifically, the unsealing needle 429 is configured to pierce the thermosensitive adhesive tube 412, thereby achieving unsealing.

[0041] It should be noted that the tip of the unsealing needle 412 always faces the side end face of one end of the heat-sensitive adhesive tube 412, and the unsealing needle 412 can be arranged horizontally or inclined relative to the horizontal.

[0042] like Figure 2As shown, in some embodiments of this application, the anchor packer assembly 5 includes an anchor packer body 51 connected to the oil pipe 2 and anchoring claws 52 disposed on the anchor packer body 51 and extending toward the inner wall of the casing 1. Specifically, when high-pressure fluid is injected into the oil pipe 2, the anchor packer assembly 5, under the action of the high-pressure fluid, causes the anchoring claws 52 to extend toward the inner wall of the casing 1, thereby ensuring that the entire anchor packer assembly 5 can be fixed inside the casing 1, thus ensuring that the entire steam injection string of this application can be fixed inside the casing 1 and preventing it from falling off.

[0043] like Figure 1 Figure 1 As shown, in some embodiments of this application, the constant-seating-force thermosensitive long rubber sleeve steam injection string further includes a ball basket 8 and a steam injection valve 9. The ball basket 8 is located below the ball seat assembly 6 and is adapted to receive the ball 7 inserted into the oil pipe 2. The steam injection valve 9 is located on the oil pipe 2 connecting the ball basket 8 and the ball seat assembly 6. Specifically, during steam injection, steam is injected into the oil pipe 2. At this time, the thermosensitive rubber sleeve 412 expands due to heat, thereby sealing the upper and lower spaces within the sleeve 1 where the thermosensitive packer assembly 4 is located. At this time, the thermal adhesive sleeve 412 is subjected to the pressure of the upper connector assembly 41 and the lower end of the hydraulic release telescopic tube assembly 3. When the pressure of the thermal adhesive sleeve 412 is too high, the thermal adhesive sleeve 412 can push the upper connector assembly 41 and the hydraulic release telescopic tube assembly 3 to ensure that the pressure of the thermal adhesive sleeve 412 is balanced with the self-weight of the upper connector assembly 41 and the hydraulic release telescopic tube assembly 3. At this time, the thermal adhesive sleeve 412 is axially elongated, but the setting force of the thermal adhesive sleeve 412 remains constant.

[0044] It should be noted that the ball seat assembly 6 is a conventional ball seat. Inserting the ball 7 into the steam injection column of this application can seal the space inside the steam injection column above the ball seat assembly 6. At this time, liquid is injected into the column to pressurize it and increase the liquid pressure inside the steam injection column. With the help of other tools such as hydraulic switches (e.g., steam injection valve 9), when the pressure exceeds the set threshold, the shear pin (not shown in the figure) inside the ball seat assembly 6 will be broken, and the ball seat assembly 6 will fall into the ball basket 8. At this time, the upper part of the steam injection column of the ball seat assembly 6 is connected to the lower part of the steam injection column.

[0045] In summary, after setting, the constant setting force heat-sensitive long rubber sleeve steam injection pipe column of the application is lowered (at this time, the ball seat assembly 6 is in an open state, and there is no ball in the ball seat assembly 6), and the ball 7 is put into the oil pipe 2, and the ball 7 is clamped at the opening of the ball seat assembly 6, at this time, the ball seat assembly 6 is in a sealed state. By injecting high-pressure fluid into the oil pipe 2 (for example, injecting clean water into the oil pipe 2 of the constant setting force heat-sensitive long rubber sleeve steam injection pipe column), the pressure in the constant setting force heat-sensitive long rubber sleeve steam injection pipe column starts to rise, and when the pressure in the constant setting force heat-sensitive long rubber sleeve steam injection pipe column reaches a certain degree, the anchoring packer assembly 5 extends towards the casing 1 and is anchored on the inner wall of the casing 1, and the hydraulic release telescopic pipe assembly 3 extends in the axial direction, so that the upper joint assembly 41 and the lower joint assembly 42 of the heat-sensitive packer assembly 4 move relatively, steam is injected into the oil pipe 2, and the heat-sensitive packer assembly 4 expands towards the inner wall of the casing 1 after being heated and seals and blocks the casing 1. It can be seen that the pipe column weight between the heat-sensitive packer assembly 4 and the hydraulic release telescopic pipe assembly 3 of the application is used to balance the setting force of the heat-sensitive packer assembly 4, so that the heat-sensitive packer assembly 4 can not be affected by the steam injection temperature and can always maintain a constant setting force during the working process. At the same time, the heat-sensitive rubber sleeve 42 in the heat-sensitive packer assembly 4 of the application adopts a long rubber sleeve design, thereby greatly increasing the contact area between the heat-sensitive rubber sleeve 412 in the heat-sensitive packer assembly 4 and the casing 1, effectively reducing the setting pressure of the heat-sensitive packer assembly 4 on the casing 1, and further reducing the damage of the heat-sensitive packer assembly 4 to the casing 1.

[0046] In the description of the present specification, the description of the terms "one embodiment", "some embodiments", "an example", "a specific example", or "some examples" and the like means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and integrate different embodiments or examples described in the present specification.

[0047] In addition, the technical solutions of each embodiment can be combined with each other, but it must be based on the fact that a person skilled in the art can realize it, and when the combination of technical solutions appears contradictory or cannot be realized, it should be considered that the combination of technical solutions does not exist and is not within the protection scope required by the present application.

[0048] While the embodiments of the present application have been shown and described, it is to be understood that the embodiments can be varied, modified, substituted and changed by those skilled in the art without departing from the principles and spirit of the present application, the scope of which is defined by the claims and their equivalents.

Claims

1. A constant setting force heat-sensitive long rubber-encased steam injection string, characterized in that, The hydraulic release telescopic pipe assembly, the heat-sensitive packer assembly, the anchoring packer assembly and the ball seat assembly are arranged in the casing and are communicated in sequence through the oil pipe. The heat-sensitive packer assembly includes the upper joint assembly and the lower joint assembly. The upper joint assembly includes an outer central pipe and a heat-sensitive rubber sleeve arranged on the outer central pipe. The upper joint assembly further includes an upper connector and an upper joint. The lower joint assembly includes an inner central pipe. An annular recess is arranged on the outer central pipe and faces the inner central pipe. A through hole is arranged on the outer wall of the inner central pipe and is communicated with the buffer chamber. The lower joint assembly further includes a lower connector. The lower joint assembly further includes a lower joint partially arranged on the lower connector and detachably connected with the lower connector.

2. The constant setting force heat-sensitive long rubber- bladder gas injection string of claim 1, wherein, The lower joint assembly further includes an outer sleeve ring and a releasing needle seat arranged on the lower connector.

3. The constant setting force heat-sensitive long rubber- bladder gas injection string of claim 2, wherein, The lower joint assembly further includes a releasing needle arranged on the releasing needle seat and extending towards the side end surface of one end of the heat-sensitive rubber sleeve.

4. The constant setting force heat-sensitive long rubber- bladder gas injection string of claim 3, wherein, The anchoring packer assembly includes an anchoring packer body communicated with the oil pipe and an anchoring claw arranged on the anchoring packer body and extending towards the inner wall of the casing.

5. The constant setting force heat-sensitive long rubber- bladder gas injection string of claim 4, wherein, ​ 6. The constant setting force heat-sensitive long rubber- bladder gas injection string of claim 1, wherein, ​ 7. The constant setting force heat-sensitive long rubber- bladder gas injection string of claim 1, wherein, The constant setting force heat-sensitive long rubber sleeve steam injection pipe column further comprises a ball basket and a steam injection valve, wherein the ball basket is arranged below the ball seat assembly and is adapted to catch the ball put into the oil pipe, and the steam injection valve is arranged on the oil pipe connecting the ball basket and the ball seat assembly.

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