Positioning insert seal capable of withstanding high-low temperature alternation

Abstract

The application provides a positioning and inserting seal capable of bearing high and low temperature alternation, and belongs to the field of inserting seal devices for oil and gas field development. The device comprises an upper core pipe, a composite seal, a connecting double male, a movable sleeve, a disc spring, a compensation pressure sleeve, an outer sleeve, a shear pin, a lower core pipe, a C-shaped tooth ring, a conversion joint, a mud scraping ring, a positioning joint and a soluble guide shoe. The device adopts a method of lower positioning and upper pipe column ballast to forcibly extrude and expand the composite seal, so that the metal seal and the non-metal seal seal the wellbore at the same time. The metal seal has better sealing effect at high temperature, and the non-metal seal has better effect at low temperature. The combination of the two solves the sealing problem of high and low temperature alternating wells. Meanwhile, the device adopts a combination mechanism of a sawtooth-shaped opening lock ring and an energy storage disc spring to offset the material stress change caused by temperature change, ensure the continuous force of the seal, and ensure better sealing effect at high and low temperatures.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of insert seal devices for oil and gas field development, and particularly relates to a positioning insert seal capable of bearing high-low temperature alternation. BACKGROUND

[0002] In the development process of heavy oil fields, in order to increase the flowability of crude oil, high-temperature hot steam is usually injected into the formation to increase the temperature of the formation crude oil and reduce the viscosity of the crude oil. In order to control the flow direction of the injected steam and reduce heat loss, a high-temperature packer or an insert seal is needed to ensure that all the steam can directly enter the target layer and prevent the steam from entering the oil-casing annulus.

[0003] At present, the conventional positioning insert seal mainly has two types: one is a rubber vulcanization ring structure, which uses rubber material to achieve interference sealing; and the other is a hard sealing form such as V-shaped seal or a pan seal, and the sealing material is mostly non-elastic material such as PTFE and PEEK. The highest applicable temperature of the above sealing forms can only reach 300 DEG C, and cannot meet the high temperature of 350 DEG C in the downhole of the current heavy oil thermal recovery well.

[0004] In the steam stimulation oil well, the positioning insert seal not only involves the problem of high temperature, but also involves the problem of high-low temperature alternation (low temperature 50 DEG C, high temperature 350 DEG C). Many sealing structures and materials can meet the continuous high temperature, but once the temperature is lowered, the sealing will fail. Therefore, there is an urgent need for a positioning insert seal device capable of adapting to the high-low temperature alternation of the thermal recovery well. SUMMARY

[0005] Therefore, the present application aims to provide a positioning insert seal capable of bearing high-low temperature alternation, self-locking and temperature compensation, which can meet the high-low temperature alternation of the thermal recovery well.

[0006] To achieve the above object, the technical scheme of the present application is as follows: A positioning and inserting seal capable of bearing high-low temperature alternation, comprising an upper core pipe and a lower core pipe, the right end of the upper core pipe is threadedly connected with the lower core pipe, the outer part of the upper core pipe is provided with a connecting double male, the left end of the connecting double male is threadedly connected with a composite seal, and the right end is threadedly connected with a movable sleeve, the right end of the movable sleeve is provided with a compensation pressing sleeve, and the variable diameter step provided on the inner surface of the right end of the movable sleeve is matched with the limiting step provided on the left end of the compensation pressing sleeve, the connecting double male, the movable sleeve and the compensation pressing sleeve are cooperatively connected to form a cavity, a plurality of disc springs are arranged in the cavity, the outer part of the lower core pipe is provided with an outer sleeve, the left end of the outer sleeve is threadedly connected with the compensation pressing sleeve, and the right end is threadedly connected with a conversion joint, a positioning joint and a soluble guide shoe in sequence, the outer sleeve is in a cylindrical structure, the inner surface of the outer sleeve is provided with fine thread, a C-shaped tooth ring is arranged between the outer sleeve and the lower core pipe, the outer surface of the C-shaped tooth ring is threadedly connected with the outer sleeve, and the inner surface is threadedly connected with the lower core pipe, the outer surface of the lower core pipe is provided with an annular groove, a plurality of circumferentially distributed thread holes are arranged at the position corresponding to the annular groove of the outer sleeve, the thread holes are connected with shear pins, and the lower ends of the shear pins extend into the annular groove.

[0007] Further, the left end of the upper core pipe is provided with a threaded structure connected with other pipe columns, the outer surface is sequentially provided from left to right with an outer sealing surface matched with the composite seal and a guide surface, and the rightmost end is provided with a threaded structure connected with the lower core pipe.

[0008] The composite seal comprises a metal sealing base and a plurality of non-metal sealing rings, the outer surface of the metal sealing base is provided with a plurality of annular grooves, the left end of the inner surface is provided with a guide surface, and the right end is provided with a threaded structure, the annular grooves are equidistantly distributed, and the size of each annular groove is the same, and one non-metal sealing ring is correspondingly arranged in each annular groove.

[0009] Further, the outer diameter of the outer sealing surface is smaller than the inner diameter of the composite seal, and the guide surface and the guide surface of the upper core pipe have the same angle and smoothness.

[0010] Further, the non-metal sealing ring is made of high-temperature hard plastic material and is integrally bonded by high-temperature vulcanization process, the non-metal sealing ring has the same width as the annular groove, and the outer diameter of the non-metal sealing ring is 0.5mm-1mm larger than the outer diameter of the metal sealing base.

[0011] Further, the connecting double male is provided with threaded structures at both ends, the movable sleeve is in a thin-walled cylindrical structure, the left end of the movable sleeve is provided with a threaded structure, and the right end of the movable sleeve is provided with a variable diameter step, the right end of the compensation pressing sleeve is provided with a threaded structure, and the left end of the compensation pressing sleeve is provided with a limiting step.

[0012] The inner surface of the left end of the lower core pipe is provided with a threaded structure, connected with the upper core pipe, and the outer surface of the right end is provided with a sawtooth threaded structure, connected with the C-shaped tooth ring; the outer surface of the left end of the conversion joint is provided with a threaded structure, and the inner surface of the right end is provided with a threaded structure; the outer surface of the left end of the positioning joint is provided with a threaded structure, and the inner surface of the right end is provided with a threaded structure.

[0013] Further, the disc springs have the same structural size, a plurality of groups of disc springs are installed in coincidence, the left ends of the plurality of groups of disc springs are aligned and extruded with the connecting double public, and the right ends are aligned and extruded with the compensation pressure sleeve.

[0014] Further, the two ends of the outer sleeve are respectively provided with threaded structures, and the fine tooth thread provided on the inner surface of the outer sleeve is a sawtooth thread.

[0015] Further, the C-shaped tooth ring is an open ring structure, and an opening part is arranged on the ring structure, so that the C-shaped tooth ring has a certain elasticity, the outer surface of the C-shaped tooth ring has a fine tooth sawtooth thread with the same tooth type as the inner wall of the outer sleeve, and the inner surface has a coarse tooth sawtooth thread connected with the lower core pipe.

[0016] Further, the outer surface of the conversion joint is provided with a sealing plane, and a mud scraping ring is arranged in the sealing plane, the mud scraping ring is a multi-ring elastic body, the inner surface of the multi-ring elastic body is a smooth surface, and the outer surface has uniformly distributed trapezoidal ring structures; the mud scraping ring is made of PTFE, PEEK or other similar oil-resistant plastic materials.

[0017] Further, the soluble guide shoe is made of soluble aluminum-magnesium alloy material, one end of the soluble guide shoe is provided with a connecting thread, the other end is provided with a large chamfer structure, and the inner surface of the soluble guide shoe is provided with a plurality of groups of internally tangent flow grooves.

[0018] Compared with the prior art, the positioning insertion seal capable of bearing high-low temperature alternation has the following advantages:

[0019] (1) The positioning insertion seal disclosed by the present application adopts the method of lower positioning and upper pipe column ballast, forcibly extrudes and expands the composite sealing element, so that the metal sealing element and the non-metal sealing element seal the wellbore at the same time, the metal sealing element has better sealing effect at high temperature, the non-metal sealing element has better effect at low temperature, and the combination of the two solves the problem of high-low temperature alternation well sealing;

[0020] (2) In order to compensate for the fluctuation of extrusion load caused by temperature change, the present application utilizes the characteristics that the sawtooth lock ring can only move in one direction and the large load energy storage advantage of the disc spring, so as to ensure that the insertion seal after ballast has a continuous force to ensure the best sealing effect;

[0021] (3) The positioning plug seal of the present application adopts soluble guide shoe structure in the lower part, which can ensure the safe running and reliable positioning of the positioning plug seal; the soluble material maximizes the inner diameter of the positioning plug seal after a certain time of dissolution. BRIEF DESCRIPTION OF DRAWINGS

[0022] The accompanying drawings, which form a part of the present application, are used to provide further understanding of the present application, and serve as an aid in explaining the exemplary embodiments of the present application and their descriptions, and are not intended as improper limitations on the present application. In the drawings:

[0023] Figure 1 Structure schematic view of the positioning plug seal capable of withstanding high-low temperature alternation according to the embodiments of the present application;

[0024] Figure 2 Enlarged schematic view of A part in Figure 1 ;

[0025] Figure 3 Enlarged schematic view of B part in Figure 1 ;

[0026] Figure 4 Enlarged schematic view of C part in Figure 1 ;

[0027] Figure 5 Structure schematic view of C type tooth ring according to the embodiments of the present application;

[0028] Figure 6 Sectional view schematic view of E-E in Figure 5 ;

[0029] Figure 7 Structure schematic view of soluble guide shoe according to the embodiments of the present application;

[0030] Figure 8 Sectional view schematic view of F-F in Figure 7 .

[0031] Explanation of reference signs:

[0032] 1, upper core pipe; 1.1, outer sealing surface; 1.2, guide surface;

[0033] 2, composite sealing element; 2.1, metal sealing base; 2.2, non-metal sealing ring; 2.3, guide surface;

[0034] 3, connecting double male; 4, movable sleeve; 5, disc spring; 6, compensation pressure sleeve; 7, outer sleeve; 8, shear pin; 9, lower core pipe;

[0035] 10, C type tooth ring; 10.1, coarse tooth sawtooth thread; 10.2, fine tooth sawtooth thread; 10.3, opening part;

[0036] 11, conversion joint; 12, mud scraping ring; 13, positioning joint;

[0037] 14, soluble guiding shoe; 14.1, connecting thread; 14.2, groove; 14.3, large chamfer. DETAILED DESCRIPTION

[0038] It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict.

[0039] The present application will be described in detail below with reference to the accompanying drawings and in conjunction with the embodiments.

[0040] In view of the limitations of the commonly used positioning insert seal in the application of heavy oil thermal recovery, the present application provides a large-diameter positioning insert seal device that meets the requirements of high and low temperature alternation, self-locking and temperature compensation in thermal recovery wells.

[0041] As shown in Figures 1-8 The present application is a positioning insert seal that can withstand high and low temperature alternation, which comprises an upper core pipe 1 and a lower core pipe 9, the right end of the upper core pipe 1 is threadedly connected with the lower core pipe 9, the outer part of the upper core pipe 1 is provided with a connecting double male 3, the left end of the connecting double male 3 is threadedly connected with a composite sealing element 2, and the right end is threadedly connected with a movable sleeve 4, the right end of the movable sleeve 4 is provided with a compensation pressure sleeve 6, and the variable diameter step provided on the inner surface of the right end of the movable sleeve 4 is in close contact with the limiting step provided on the left end of the compensation pressure sleeve 6, the connecting double male 3, the movable sleeve 4 and the compensation pressure sleeve 6 are connected in cooperation to form a cavity, and a plurality of disc springs 5 are arranged in the cavity.

[0042] The outer part of the lower core pipe 9 is provided with an outer sleeve 7, the outer sleeve 7 is a cylindrical structure, and the two ends thereof are respectively provided with thread structures, the left end of the outer sleeve 7 is threadedly connected with the compensation pressure sleeve 6, and the right end is sequentially threadedly connected with a conversion joint 11, a positioning joint 13 and a soluble guiding shoe 14, and the inner surface of the outer sleeve 7 is provided with a fine-tooth sawtooth thread 10.2, a C-shaped tooth ring 10 is arranged between the outer sleeve 7 and the lower core pipe 9, the outer surface of the C-shaped tooth ring 10 has the same tooth type of the fine-tooth sawtooth thread 10.2 as the inner wall of the outer sleeve 7 and is connected with the outer sleeve 7, and the inner surface has a coarse-tooth sawtooth thread 10.1 and is connected with the lower core pipe 9, the C-shaped tooth ring 10 is an open ring structure, and an opening part 10.3 is arranged on the ring structure, so that the C-shaped tooth ring 10 has a certain elasticity. When the lower core pipe 9 drives the C-shaped tooth ring 10 to move to the right, the fine-tooth sawtooth thread 10.2 of the C-shaped tooth ring 10 can be disengaged from the thread engagement of the outer sleeve 7 under elastic deformation and move to the right. Due to the one-way passing characteristics of the sawtooth thread, after the lower core pipe 9 drives the C-shaped tooth ring 10 to move to the right, it cannot be returned.

[0043] The outer surface of the lower core pipe 9 is provided with an annular groove, the outer sleeve 7 is provided with a plurality of circumferentially distributed threaded holes corresponding to the position of the annular groove, and each threaded hole is respectively connected with a shear pin 8, and the lower end of the shear pin 8 extends into the annular groove. The shear pin 8 is made of brass or stainless steel and is easy to shear when the acting force exceeds the shear stress. In actual work, the shear pin 8 is used to fix the outer sleeve 7 and the lower core pipe 9 and is sheared under the action of gravity when working. In the description of the present application, it should be understood that the terms "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" and the like indicate the orientation or positional relationship shown in the drawings, and are only used for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application.

[0044] The left end of the upper core pipe 1 is provided with a threaded structure connected with other pipe columns, and the outer surface is sequentially provided from left to right with an outer sealing surface 1.1 matched with the composite sealing element 2 and a guide surface 1.2, and the rightmost end is provided with a threaded structure connected with the lower core pipe 9. The inner diameter of the upper core pipe 1 is a standard casing inner diameter.

[0045] The composite sealing element 2 comprises a metal sealing base 2.1 and a plurality of high-temperature-resistant non-metal sealing rings 2.2. The outer surface of the metal sealing base 2.1 is provided with a plurality of annular grooves, the inner surface is provided with a guide surface 2.3 at the left end and a threaded structure at the right end. The annular grooves are equally distributed, and the size of each annular groove is the same. One non-metal sealing ring 2.2 is installed in each annular groove. In this embodiment, the non-metal sealing ring 2.2 is preferably provided in four groups, and more groups can be used in actual application. In the description of the present application, "a plurality of groups" means two groups or more, unless otherwise specified. The present application adopts the method of lower positioning and upper pipe column ballast to forcibly extrude and expand the composite sealing element 2, so that the metal sealing base 2.1 and the non-metal sealing ring 2.2 seal the wellbore at the same time. The wellbore is the existing foundation. The metal sealing base 2.1 has better sealing effect at high temperature, and the non-metal sealing ring 2.2 has better effect at low temperature. The combination of the two effectively solves the sealing problem of high-low temperature alternating wells.

[0046] The outer diameter of the outer sealing surface 1.1 is smaller than the inner diameter of the composite sealing element 2; the guide surface 2.3 and the guide surface 1.2 of the upper core pipe 1 have the same angle and smoothness, so that they can smoothly slide on the contact surface.

[0047] The non-metal sealing ring 2.2 is made of high-temperature hard plastic material and is bonded into one body by high-temperature vulcanization process, the non-metal sealing ring 2.2 has the same width as the annular groove, and the outer diameter of the non-metal sealing ring 2.2 is 0.5-1mm larger than the outer diameter of the metal sealing base 2.1.

[0048] The connecting double male 3 is provided with a threaded structure at both ends; the movable sleeve 4 is a thin-walled cylinder structure, the left end of which is provided with a threaded structure, and the inner surface of the right end is provided with a variable-diameter step; the right end of the compensation pressure sleeve 6 is provided with a threaded structure, and the left end is provided with a limiting step, and the two steps can form a limiting effect after cooperation; the compensation pressure sleeve 6 and the connecting movable sleeve 4 are not threadedly connected, and the two can move horizontally relative to each other; a plurality of disc springs 5 are arranged in the cavity formed by the cooperation and connection of the connecting double male 3, the movable sleeve 4 and the compensation pressure sleeve 6, the plurality of disc springs 5 have the same structure size, the plurality of disc springs 5 are installed in superposition, the left end of the plurality of disc springs 5 is in alignment with the connecting double male 3 for extrusion, and the right end is in alignment with the compensation pressure sleeve 6 for extrusion. In the actual working process, the composite sealing element 2 is extruded at the same time, and the force is also compressed on the disc spring 5, so that the disc spring 5 can store the force in the construction process in its interior, and after the pipe column force disappears, the disc spring 5 can provide a lasting leftward thrust to push the composite sealing element 2 to move leftward, and make the metal sealing base 2.1 and the non-metal sealing ring 2.2 of the composite sealing element 2 adhere to the inner wall of the sealing cylinder for sealing. Especially under low temperature conditions, the metal sealing base 2.1 and the sealing cylinder fail to seal due to cold shrinkage, at this time, the thrust provided by the disc spring 5 can make the two always adhere to seal.

[0049] The inner surface of the left end of the lower core pipe 9 is provided with a normal threaded structure, which is connected with the upper core pipe 1, and the outer surface of the right end is provided with a sawtooth threaded structure, which is connected with the C-shaped tooth ring 10; the outer surface of the left end of the conversion joint 11 is provided with a threaded structure, and the inner surface of the right end is provided with a threaded structure; the outer surface of the left end of the positioning joint 13 is provided with a threaded structure, and the inner surface of the right end is provided with a threaded structure.

[0050] The outer surface of the conversion joint 11 is provided with a sealing plane, and the sealing plane is provided with a mud scraping ring 12 installed therein, which is used to clean the inner surface of the sealing cylinder in advance, can remove dirt and impurities on the surface of the sealing cylinder, and ensure that the composite sealing element 2 can have a better sealing environment, so as to ensure the sealing effect of the positioning insertion sealing, the mud scraping ring 12 is a multi-ring elastomer, the inner surface of the multi-ring elastomer is a smooth surface, and the outer surface has uniformly distributed trapezoidal ring structures; the mud scraping ring 12 is made of PTFE, PEEK or other similar oil-resistant plastic materials, the mud scraping ring made of PTFE and PEEK has the characteristics of small sliding friction resistance, can produce certain deformation and will not scratch the inner surface of the sealing cylinder, and can meet the requirements of safe running-in of the entire insertion sealing.

[0051] The soluble guide shoe 14 is made of soluble aluminum magnesium alloy material, one end of which is provided with a connecting thread 14.1 connected with the positioning sub 13, and the other end is provided with a large chamfer 14.3 structure, which is beneficial to the centralization and guidance during running, and the inner surface of which is provided with a plurality of inner tangent flow grooves for flow during oil production and to accelerate the dissolution rate. The soluble guide shoe 14 is used to assist the positioning sub 13 to smoothly enter the wellbore, and automatically dissolve in the liquid and gradually disappear after the positioning is completed.

[0052] The positioning and inserting sealing device is used, the left end thread of the positioning and inserting sealing device is connected with other pipe strings and is run into the well, and the other pipe strings are the existing foundation. After running into the well, the positioning sub 13 first enters the inside of the expected wellbore, and since the soluble guide shoe 14 has a large chamfer 14.3 as a larger guide angle, it can be adapted to a high angle well or a horizontal well, avoiding a large resistance caused by an ordinary guide shoe, which leads to the shear pin 8 being cut off in advance. At the same time, the mud scraping ring 12 is a multi-ring elastomer, which can remove dirt and impurities on the surface of the sealing cylinder to ensure the sealing effect of the positioning and inserting sealing device.

[0053] Once the positioning sub 13 enters the expected positioning step position, the positioning and inserting sealing device no longer continues to run down, and the weight of the upper pipe string gradually acts on the upper core pipe 1, the lower end thread of the upper core pipe 1 transmits the force to the lower core pipe 9, and the lower core pipe 9 transmits the force to the shear pin 8. Since the shear pin 8 is made of brass or stainless steel material and is an easy-to-cut material, when the force exceeds the shear stress, the shear pin 8 is cut off, and the upper core pipe 1 and the lower core pipe 9 continue to run down, at the same time driving the C-shaped tooth ring 10 to run down and being locked on the inner surface fine sawtooth thread 10.2 of the outer sleeve 7 and no longer moving.

[0054] Referring to Figure 2 At the same time of the movement of the upper core pipe 1, the composite sealing element 2 will climb the outer sealing surface 1.1 along the guide surface 1.2 of the outer surface of the upper core pipe 1 and expand under the extrusion of the outer sealing surface 1.1, so that the metal sealing base 2.1 and the non-metal sealing ring 2.2 of the composite sealing element 2 are uniformly expanded and enlarged and tightly adhere to the inner surface of the expected downhole sealing cylinder, forming a forced multiple sealing effect.

[0055] Referring to Figure 3 At the same time of the extrusion of the composite sealing element 2, the force also compresses the disc spring 5, so that the disc spring 5 can store the force in the disc spring 5 during the construction process, and after the pipe string force disappears, the disc spring 5 can provide a lasting extrusion force, especially under the condition of high and low temperature alternation, the disc spring 5 also acts as a temperature compensation to compensate the metal deformation caused by temperature.

[0056] The above merely provides the preferred embodiment of the present application, and is not used to limit the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims

1. A positioning insert seal capable of withstanding high low temperature cycling, characterized by: The utility model provides a kind of double-connection casing pipe, including upper core pipe (1) and lower core pipe (9), the right end of the upper core pipe (1) is threadedly connected with lower core pipe (9), the outside of the upper core pipe (1) is provided with connecting double male (3), the left end of the connecting double male (3) is threadedly connected with composite seal (2), right end is threadedly connected with movable sleeve (4), the right end of the movable sleeve (4) is provided with compensation pressure sleeve (6), while the right end inner surface of the movable sleeve (4) is provided with the diameter change step and the limiting step of the left end of the compensation pressure sleeve (6) is attached, the connecting double male (3), movable sleeve (4) and compensation pressure sleeve (6) are formed with a cavity after being connected with three, multiple disc springs (5) are provided in cavity, the outside of the lower core pipe (9) is provided with outer sleeve (7), the left end of the outer sleeve (7) is threadedly connected with compensation pressure sleeve (6), right end is threadedly connected with conversion joint (11), positioning joint (13) and soluble guide shoe (14) in proper order, the outer sleeve (7) is cylindrical structure, and the inner surface of the outer sleeve (7) is provided with fine thread, C type tooth ring (10) is arranged between the outer sleeve (7) and lower core pipe (9), the outer surface of the C type tooth ring (10) is threadedly connected with the outer sleeve (7), and the inner surface is threadedly connected with the lower core pipe (9);The outer surface of the lower core pipe (9) is provided with annular groove, the outer sleeve (7) is provided with multiple circumferentially distributed screw holes at the position corresponding to the annular groove, and the screw hole is connected with shear nail (8) inside, while the lower end of shear nail (8) is inserted into annular groove; The left end of the upper core pipe (1) is provided with threaded structure connected with other pipe columns, and the outer surface is sequentially provided with outer sealing surface (1.1) and guide surface (1.2) matched with composite seal (2) from left to right, and the rightmost end is provided with threaded structure connected with lower core pipe (9); The composite seal (2) includes metal sealing base (2.1) and multiple non-metallic sealing rings (2.2), the outer surface of the metal sealing base (2.1) is provided with multiple annular grooves, the inner surface is provided with guide surface (2.3) at the left end, and is provided with threaded structure at the right end, the annular grooves are equidistantly distributed, and the size of each annular groove is same, and one non-metallic sealing ring (2.2) is installed in each annular groove; The two ends of the connecting double male (3) are respectively provided with threaded structure;The movable sleeve (4) is thin-walled cylinder structure, and the left end is provided with threaded structure, and the right end inner surface is provided with diameter change step;The right end of the compensation pressure sleeve (6) is provided with threaded structure, and the left end is provided with limiting step; The inner surface of the left end of the lower core pipe (9) is provided with threaded structure, is connected with the upper core pipe (1), and the outer surface of the right end is provided with sawtooth thread structure, is connected with C type tooth ring (10);The outer surface of the left end of the conversion joint (11) is provided with threaded structure, and the inner surface of the right end is provided with threaded structure;The outer surface of the left end of the positioning joint (13) is provided with threaded structure, and the inner surface of the right end is provided with threaded structure; The two ends of the outer sleeve (7) are respectively provided with threaded structure, and the fine thread provided in the inner surface of the outer sleeve (7) is sawtooth thread; The C-shaped tooth ring (10) is an open ring structure, and an opening (10.3) is arranged on the open ring structure, so that the C-shaped tooth ring (10) has a certain elasticity, the outer surface of the C-shaped tooth ring (10) is provided with a fine-tooth sawtooth thread (10.2) with the same tooth shape as the inner wall of the outer sleeve (7), and the inner surface is provided with a coarse-tooth sawtooth thread (10.1) connected with the lower core pipe (9).

2. The positioning insert seal capable of withstanding high-low temperature cycling of claim 1, wherein: The outer diameter of the outer sealing surface (1.1) is smaller than the inner diameter of the composite sealing element (2); the guide surface (2.3) has the same angle and smoothness as the guide surface (1.2) of the upper core pipe (1).

3. The positioning insert seal capable of withstanding high-low temperature cycling of claim 1, wherein: The non-metallic sealing ring (2.2) is made of high-temperature hard plastic material and is bonded into one body by high-temperature vulcanization process, the non-metallic sealing ring (2.2) has the same width as the annular groove, and the outer diameter of the non-metallic sealing ring (2.2) is 0.5mm-1mm larger than the outer diameter of the metal sealing base (2.1).

4. The positioning insert seal capable of withstanding high-low temperature cycling of claim 1, wherein: The disc springs (5) have the same structure and size, a plurality of disc springs (5) are installed in a superimposed manner, the left ends of the plurality of disc springs (5) are aligned and extruded with the connecting double male (3), and the right ends are aligned and extruded with the compensation pressure sleeve (6).

5. The positioning insert seal capable of withstanding high-low temperature cycling of claim 1, wherein: The outer surface of the conversion joint (11) is provided with a sealing plane, the sealing plane is provided with a mud scraping ring (12), the mud scraping ring (12) is a multi-ring elastic body, the inner surface of the multi-ring elastic body is a smooth surface, and the outer surface has a uniformly distributed trapezoidal circular ring structure.

6. The positioning insert seal of claim 1, wherein: The soluble guide guide shoe (14) is made of soluble aluminum magnesium alloy material, one end of which is provided with a connecting thread (14.1), the other end is provided with a large chamfer (14.3) structure, and the inner surface is provided with a plurality of inner tangent flow grooves.

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