High-temperature and high-pressure expansion joint sealing structure

Abstract

The utility model provides a sealing structure of a high-temperature and high-pressure expansion joint. The mandrel is arranged on the inner side face of the outer cylinder, one end of the outer side face of the mandrel is sleeved with a pressing ring, a pressing nut is arranged on one side of the pressing ring, a back ring is arranged on the other side of the pressing ring, the pressing nut is in threaded connection with one end of the outer side face of the mandrel, and a sealing ring is arranged on one side of the back ring. According to the high-temperature and high-pressure expansion joint sealing structure provided by the utility model, the wiping rings are arranged on the mandrel and the compression nut, and the sealing structure is arranged between the two wiping rings, so that silt on the inner wall of the outer cylinder can be pushed and scraped during subsequent use and when the outer cylinder and the mandrel move; silt is prevented from entering the position of the sealing structure, so that friction between the sealing structure and the silt is avoided, and the sealing stability of the sealing structure is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of petroleum engineering, in particular to a high-temperature and high-pressure expansion joint sealing structure. Background Art

[0002] The high-temperature and high-pressure expansion joint is an expansion joint suitable for high-temperature and high-pressure wells in oil fields. It can greatly expand the range of ultra-deep well test application wells, provide a solid equipment foundation for ultra-deep well exploration and development, and provide strong technical support for the development of ultra-deep well petroleum engineering market.

[0003] The expansion joint includes a center tube and an outer tube. The center tube reciprocates in the outer tube. A sealing structure is designed between the center tube and the outer tube. The commonly used sealing form is O-ring sealing, which has the advantages of simple structure, low cost, and simple installation and operation. It is often used in static sealing with a pressure below 70MPa and a temperature below 150°C. Combined with the structure and function of the expansion joint, the center tube and the outer tube are dynamically sealed. If only O-rings are used as sealing elements, it is inevitable that mud and sand will enter between the outer tube and the center tube when used in the well, causing friction between the seal and the mud and sand. After long-term use, the seal is easily worn, and the stability of its sealing performance cannot be guaranteed.

[0004] Therefore, it is necessary to provide a high-temperature and high-pressure expansion joint sealing structure to solve the above technical problems. Utility Model Content

[0005] The utility model provides a high-temperature and high-pressure expansion joint sealing structure, which solves the problem that mud and sand entering the interior of the outer cylinder and the friction between the sealing structure easily cause the seal to wear and the stability of its sealing performance cannot be guaranteed.

[0006] In order to solve the above technical problems, the utility model provides a high-temperature and high-pressure expansion joint sealing structure, comprising:

[0007] outer cylinder;

[0008] A core shaft, the core shaft is arranged on the inner side surface of the outer cylinder, one end of the outer side surface of the core shaft is sleeved with a pressure ring, one side of the pressure ring is provided with a clamping nut, the other side of the pressure ring is provided with a back ring, the clamping nut is threadedly connected to one end of the outer side surface of the core shaft, one side of the back ring is provided with a sealing ring, the sealing ring is sleeved on the outer side surface of the core shaft, one side of the sealing ring is provided with a first supporting seal, one side of the first supporting seal is provided with a first ferrule, the first supporting seal and the first ferrule are both sleeved on the outer side surface of the core shaft;

[0009] The rubbing rings are respectively sleeved on the outer side surfaces of the clamping nut and the core shaft, and the outer side surfaces of the two rubbing rings are both in contact with the inner wall of the outer cylinder.

[0010] Preferably, an upper joint is provided at one end of the inner side surface of the outer cylinder, and the outer side surface of the upper joint is also sleeved with a first support seal and a first ring. A first screw passes through the interior of one end of the outer cylinder, and one end of the first screw is threadedly connected to the interior of the upper joint.

[0011] Preferably, a lower joint is sleeved on the other end of the outer side surface of the core shaft, a second supporting seal and a second ring are provided on the outer side surface of the core shaft, the second supporting seal and the second ring are both arranged inside the lower joint, a third supporting seal is provided on the outer side surface of the lower joint, and a third ring is provided on the outer side surface of the third supporting seal.

[0012] Preferably, a spline sleeve is provided on the outer side surface of the core shaft, a key body is provided on the inner side surface of the spline sleeve, and a retaining ring is provided on the outer side surface of the spline sleeve.

[0013] Preferably, a pin is passed through the interior of the retaining ring, one end of the pin is arranged inside the core shaft, and a second screw is passed through the interior of the retaining ring, one end of the second screw is threadedly connected to the interior of the spline sleeve.

[0014] Preferably, a clamping groove is provided on one side of the lower joint, and a clamping ring is clamped on the inner side surface of the clamping groove.

[0015] Preferably, a rubber ring is fixedly connected to one side of the clamping ring.

[0016] Compared with the related art, the high-temperature and high-pressure expansion joint sealing structure provided by the utility model has the following beneficial effects:

[0017] The utility model provides a high-temperature and high-pressure expansion joint sealing structure, in which rubbing rings are arranged on the top of the core shaft and the clamping nut, and the sealing structure is arranged in the middle of the two rubbing rings. In this way, when the outer cylinder and the core shaft are used later, the mud and sand on the inner wall of the outer cylinder can be pushed and scraped off to prevent the mud and sand from entering the position of the sealing structure, thereby avoiding friction between the sealing structure and the mud and sand, and increasing the sealing stability of the sealing structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 A structural schematic diagram of a first embodiment of a high-temperature and high-pressure expansion joint sealing structure provided by the utility model;

[0019] Figure 2 for Figure 1 The schematic diagram of the outer cylinder structure shown;

[0020] Figure 3 for Figure 1 The schematic diagram of the mandrel structure shown;

[0021] Figure 4 This is a structural schematic diagram of a second embodiment of a high-temperature and high-pressure expansion joint sealing structure provided by the utility model.

[0022] Numbers in the figure: 1, upper joint, 2, locking nut, 3, outer cylinder, 4, core shaft, 5, spline sleeve, 6, key body, 7, retaining ring, 8, lower joint, 9, wiping ring, 10, pin, 11, pressure ring, 12, back ring, 13, first supporting seal, 14, second supporting seal, 15, sealing ring, 16, third supporting seal, 19, first ferrule, 20, second ferrule, 21, third ferrule, 22, first screw, 23, second screw, 31, snap-in groove, 32, snap-in ring, 33, rubber ring. DETAILED DESCRIPTION

[0023] The utility model is further described below in conjunction with the accompanying drawings and implementation modes.

[0024] First embodiment

[0025] Please refer to Figure 1 , Figure 2 , Figure 3 ,in, Figure 1 A structural schematic diagram of a first embodiment of a high-temperature and high-pressure expansion joint sealing structure provided by the utility model; Figure 2 for Figure 1 The schematic diagram of the outer cylinder structure shown; Figure 3 for Figure 1 A schematic diagram of the core shaft structure is shown. A high-temperature and high-pressure expansion joint sealing structure comprises: an outer cylinder 3;

[0026] A core shaft 4, wherein the core shaft 4 is arranged on the inner side surface of the outer tube 3, a pressure ring 11 is sleeved on one end of the outer side surface of the core shaft 4, a clamping nut 2 is arranged on one side of the pressure ring 11, a back ring 12 is arranged on the other side of the pressure ring 11, the clamping nut 2 is threadedly connected to one end of the outer side surface of the core shaft 4, a sealing ring 15 is arranged on one side of the back ring 12, the sealing ring 15 is sleeved on the outer side surface of the core shaft 4, a first supporting seal 13 is arranged on one side of the sealing ring 15, a first ferrule 19 is arranged on one side of the first supporting seal 13, and both the first supporting seal 13 and the first ferrule 19 are sleeved on the outer side surface of the core shaft 4;

[0027] The rubbing rings 9 are respectively sleeved on the outer side surfaces of the clamping nut 2 and the core shaft 4 , and the outer side surfaces of the two rubbing rings 9 are both in contact with the inner wall of the outer tube 3 .

[0028] An upper joint 1 is provided at one end of the inner side of the outer tube 3, and a first supporting seal 13 and a first ferrule 19 are also sleeved on the outer side of the upper joint 1. A first screw 22 passes through the interior of one end of the outer tube 3, and one end of the first screw 22 is threadedly connected to the interior of the upper joint 1.

[0029] The other end of the outer side surface of the core shaft 4 is sleeved with a lower joint 8, and the outer side surface of the core shaft 4 is provided with a second supporting seal 14 and a second ring 20, both of which are arranged inside the lower joint 8, and the outer side surface of the lower joint 8 is provided with a third supporting seal 16, and the outer side surface of the third supporting seal 16 is provided with a third ring 21.

[0030] The outer side surface of the core shaft 4 is provided with a spline sleeve 5 , the inner side surface of the spline sleeve 5 is provided with a key body 6 , and the outer side surface of the spline sleeve 5 is provided with a retaining ring 7 .

[0031] A pin 10 passes through the interior of the retaining ring 7 , one end of which is arranged inside the core shaft 4 . A second screw 23 passes through the interior of the retaining ring 7 , one end of which is threadedly connected to the interior of the spline sleeve 5 .

[0032] The first supporting seal 13, the second supporting seal 14, and the third supporting seal 16 are all made of PEEK;

[0033] The sealing ring 15 is a V-shaped sealing ring made of fluororubber;

[0034] The first ring 19, the second ring 20 and the third ring 21 are all AFLAS O-rings. Aflas fluororubber material has the following advantages: 1. Alkali and amine resistance. Due to its unique molecular structure, it has outstanding alkali and amine resistance. 2. Steam resistance. It has excellent durability against high-temperature and high-pressure steam (except for the 200 series). 3. Electrical insulation. The volume intrinsic resistance has an extremely excellent insulation of 10-16. It also has excellent insulation for high voltage. 4. Heat resistance. The continuous use temperature is 200°C. If it is for a short time, it also has excellent heat resistance for 250°C. 5. Acid resistance. It also has excellent acid resistance for strong acids such as sulfuric acid and hydrochloric acid. 6. Oil resistance. It has excellent oil resistance, especially for oils with amine-containing anti-acidifiers. And, especially for heavy oil, its durability is better than other rubbers.

[0035] The wiping ring 9 is made of PEEK.

[0036] The working principle of a high-temperature and high-pressure expansion joint sealing structure provided by the utility model is as follows:

[0037] When in use, when the core shaft 4 moves, it will drive the clamping nut 2 to move on the inner side of the outer tube 3, and through the movement of the core shaft 4 and the clamping nut 2, it will drive the wiping ring 9 to slide on the inner wall of the outer tube 3, so as to clean the sand and gravel on the inner wall of the outer tube 3, and in subsequent use, it can be connected through the upper joint 1 and the lower joint 8, so as to connect and assemble multiple telescopic joints.

[0038] Compared with the related art, the high-temperature and high-pressure expansion joint sealing structure provided by the utility model has the following beneficial effects:

[0039] By arranging wiping rings 9 on both the core shaft 4 and the clamping nut 2, and arranging the sealing structure in the middle of the two wiping rings 9, when the outer cylinder 3 and the core shaft 4 are used later, the mud and sand on the inner wall of the outer cylinder 3 can be pushed and scraped off to prevent the mud and sand from entering the position of the sealing structure, thereby avoiding friction between the sealing structure and the mud and sand, and increasing the sealing stability of the sealing structure.

[0040] Second embodiment

[0041] Please refer to Figure 4 Based on the high-temperature and high-pressure expansion joint sealing structure provided by the first embodiment of the present application, the second embodiment of the present application proposes another high-temperature and high-pressure expansion joint sealing structure. The second embodiment is only a preferred embodiment of the first embodiment, and the implementation of the second embodiment will not affect the independent implementation of the first embodiment.

[0042] Specifically, the second embodiment of the present application provides a high-temperature and high-pressure expansion joint sealing structure, which is different in that a high-temperature and high-pressure expansion joint sealing structure is provided with a snap-in groove 31 on one side of the lower joint 8, and a snap-in ring 32 is snap-into the inner side surface of the snap-in groove 31.

[0043] A rubber ring 33 is fixedly connected to one side of the clamping ring 32 .

[0044] The working principle of a high-temperature and high-pressure expansion joint sealing structure provided by the utility model is as follows:

[0045] When in use, the clamping ring 32 is clamped into the inner side of the clamping groove 31 to install the rubber ring 33, which can play a sealing role when the upper joint 1 and the lower joint 8 are connected.

[0046] Compared with the related art, the high-temperature and high-pressure expansion joint sealing structure provided by the utility model has the following beneficial effects:

[0047] By cooperating with each other through structures such as the clamping groove 31, the clamping ring 32 and the rubber ring 33, when the upper joint 1 and the lower joint 8 are installed and connected during use, the sealing effect can be increased.

[0048] The above description is only an embodiment of the present invention, and does not limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made by using the contents of the specification and drawings of the present invention, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A high temperature and high pressure expansion joint sealing structure, characterized in that: include: outer cylinder; A core shaft, the core shaft is arranged on the inner side surface of the outer cylinder, one end of the outer side surface of the core shaft is sleeved with a pressure ring, one side of the pressure ring is provided with a clamping nut, the other side of the pressure ring is provided with a back ring, the clamping nut is threadedly connected to one end of the outer side surface of the core shaft, one side of the back ring is provided with a sealing ring, the sealing ring is sleeved on the outer side surface of the core shaft, one side of the sealing ring is provided with a first supporting seal, one side of the first supporting seal is provided with a first ferrule, the first supporting seal and the first ferrule are both sleeved on the outer side surface of the core shaft; The rubbing rings are respectively sleeved on the outer side surfaces of the clamping nut and the core shaft, and the outer side surfaces of the two rubbing rings are both in contact with the inner wall of the outer cylinder.

2. A high temperature and high pressure expansion joint sealing structure according to claim 1, characterized in that: An upper joint is arranged at one end of the inner side of the outer tube, and a first supporting seal and a first ferrule are also sleeved on the outer side of the upper joint. A first screw penetrates the interior of one end of the outer tube, and one end of the first screw is threadedly connected to the interior of the upper joint.

3. A high temperature and high pressure expansion joint sealing structure according to claim 2, characterized in that: The other end of the outer side surface of the core shaft is sleeved with a lower joint, the outer side surface of the core shaft is provided with a second supporting seal and a second ring, the second supporting seal and the second ring are both arranged inside the lower joint, the outer side surface of the lower joint is provided with a third supporting seal, and the outer side surface of the third supporting seal is provided with a third ring.

4. A high-temperature and high-pressure expansion joint sealing structure according to claim 3, characterized in that: The outer side surface of the core shaft is provided with a spline sleeve, the inner side surface of the spline sleeve is provided with a key body, and the outer side surface of the spline sleeve is provided with a retaining ring.

5. A high-temperature and high-pressure expansion joint sealing structure according to claim 4, characterized in that: A pin is passed through the interior of the retaining ring, one end of which is arranged inside the core shaft, and a second screw is passed through the interior of the retaining ring, one end of which is threadedly connected to the interior of the spline sleeve.

6. A high-temperature and high-pressure expansion joint sealing structure according to claim 5, characterized in that: A clamping groove is provided on one side of the lower joint, and a clamping ring is clamped on the inner side surface of the clamping groove.

7. A high-temperature and high-pressure expansion joint sealing structure according to claim 6, characterized in that: One side of the clamping ring is fixedly connected with a rubber ring.

Images